Tyler J. Albert, MD

THE CASE

A 52-year-old man presented to the emergency department after vomiting a large volume of blood and was admitted to the intensive care unit. His past medical history was remarkable for untreated chronic hepatitis C resulting from injection drug use and cirrhosis without prior history of esophageal varices.

Due to ongoing hematemesis, he was intubated for airway protection and underwent esophagogastroduodenoscopy with banding of large esophageal varices on hospital day (HD) 1. He was extubated on HD 2 after clinical stability was achieved; however, he became encephalopathic over the subsequent days despite treatment with lactulose. On HD 4, the patient required re-intubation for progressive respiratory failure. Chest imaging revealed a large, simple-appearing right pleural effusion and extensive bilateral patchy ground-glass opacities (FIGURE 1).

Thoracentesis was ordered and revealed transudative pleural fluid; this finding, along with negative infectious studies, was consistent with hepatic hydrothorax. In the setting of initial decompensation, empiric treatment with vancomycin and meropenem was started for suspected hospital-acquired pneumonia.

The patient had persistent fevers that had developed during his hospital stay and pulmonary opacities, despite 72 hours of treatment with broad-spectrum antibiotics. Thus, a diagnostic bronchoscopy with bronchoalveolar lavage (BAL) was performed. BAL cell count and differential revealed 363 nucleated cells/µL, with profound eosinophilia (42% eosinophils, 44% macrophages, 14% neutrophils).

Bacterial and fungal cultures and a viral polymerase chain reaction panel were negative. HIV antibody-antigen and RNA testing were also negative. The patient had no evidence or history of underlying malignancy, autoimmune disease, or recent immunosuppressive therapy, including corticosteroids. Due to consistent imaging findings and lack of improvement with appropriate treatment for bacterial pneumonia, further work-up was pursued.

THE DIAGNOSIS

Given the consistent radiographic pattern, the differential diagnosis for this patient included pneumocystis pneumonia (PCP), a potentially life-threatening opportunistic infection. Work-up therefore included direct fluorescent antibody testing, which was positive for Pneumocystis jirovecii, a fungus that can cause PCP.

Of note, the patient’s white blood cell count was elevated on admission (11.44 × 10³/µL) but low for much of his hospital stay (nadir = 1.97 × 10³/µL), with associated lymphopenia (nadir = 0.22 × 10³/µl). No peripheral eosinophilia was noted.

Continue to: DISCUSSION

 

 

DISCUSSION

PCP typically occurs in immunocompromised individuals and may be related to HIV infection, malignancy, or exposure to immunosuppressive therapies.^1,2 While rare cases of PCP have been described in adults without predisposing factors, many of these cases occurred at the beginning of the AIDS epidemic, prior to reliable HIV testing.^3-5

Uncharted territory. We were confident in our diagnosis because immunofluorescence testing has very few false-positives and a high specificity.^6-8 But there were informational gaps. The eosinophilia recorded on BAL is poorly described in HIV-negative patients with PCP but well-described in HIV-positive patients, with the level of eosinophilia associated with disease severity.^9,10 Eosinophils are thought to contribute to pulmonary inflammation, which may explain the severity of our patient’s course.¹⁰

A first of its kind case?

To our knowledge, this is the first report of PCP in a patient with cirrhosis from chronic hepatitis C virus infection and no other predisposing conditions or preceding immunosuppressive therapy. We suspect that his lymphopenia, which was noted during his critical illness, predisposed him to PCP.

Individuals with lymphopenia and low CD4+ T-cell counts have been shown to be at increased risk of pneumocystis pneumonia.

Lymphocytes (in particular CD4+ T cells) have been shown to play an important role, along with alveolar macrophages and neutrophils, in directing the host defense against P jirovecii infection.^1,3,11 Individuals with lymphopenia and low CD4+ T-cell counts have been shown to be at increased risk of PCP; risk increases markedly with CD4+ T cells below 200 cells/µL.^11-13

Typical risk factors for lymphopenia had not been observed in this patient. However, cirrhosis has been associated with low CD4+ T-cell counts and disruption of cell-mediated immunity, even in HIV-­seronegative patients.^14,15 There are several postulated mechanisms for low CD4+ T-cell counts in cirrhosis, including splenic sequestration, impaired T-cell production (due to impaired thymopoiesis), increased T-cell consumption, and apoptosis (due to persistent immune system activation from bacterial translocation and an overall pro-infl­ammatory state).^16,17

Continue to: Predisposing factors guide treatment

 

 

Predisposing factors guide treatment

Routine treatment for PCP in patients without HIV is a 21-day course of trimethoprim/­sulfamethoxazole (Bactrim). Dosing for patients with normal renal function is 15 to 20 mg/kg orally or intravenously per day. Patients with allergy to trimethoprim/sulfamethoxazole should ideally undergo desensitization, given its effectiveness against PCP.

Due to a sulfonamide allergy, our patient was started on primaquine 30 mg/d, clindamycin 600 mg tid, and prednisone 40 mg bid. (The corticosteroid was added because of the severity of the disease.) Three days after starting treatment—and 10 days into his hospital stay—the patient had significant improvement in his respiratory status and was successfully extubated. He underwent trimethoprim/sulfamethoxazole desensitization and completed a 21-day course of treatment for PCP with complete resolution of respiratory symptoms. Follow-up chest radiograph 2 months later (FIGURE 2) confirmed clearance of opacities.

THE TAKEAWAY

PCP remains a rare disease in patients without the typical immunosuppressive risk factors. However, it should be considered in patients with cirrhosis who develop respiratory failure, especially those with compatible radiographic findings and negative microbiologic evaluation for other, more typical, organisms.

CORRESPONDENCE
Tyler Albert, MD, VA Puget Sound Healthcare System, 1660 South Columbian Way, S-111-Pulm, Seattle, WA 98108; talbert@uw.edu

THE CASE

A 52-year-old man presented to the emergency department after vomiting a large volume of blood and was admitted to the intensive care unit. His past medical history was remarkable for untreated chronic hepatitis C resulting from injection drug use and cirrhosis without prior history of esophageal varices.

Due to ongoing hematemesis, he was intubated for airway protection and underwent esophagogastroduodenoscopy with banding of large esophageal varices on hospital day (HD) 1. He was extubated on HD 2 after clinical stability was achieved; however, he became encephalopathic over the subsequent days despite treatment with lactulose. On HD 4, the patient required re-intubation for progressive respiratory failure. Chest imaging revealed a large, simple-appearing right pleural effusion and extensive bilateral patchy ground-glass opacities (FIGURE 1).

Thoracentesis was ordered and revealed transudative pleural fluid; this finding, along with negative infectious studies, was consistent with hepatic hydrothorax. In the setting of initial decompensation, empiric treatment with vancomycin and meropenem was started for suspected hospital-acquired pneumonia.

The patient had persistent fevers that had developed during his hospital stay and pulmonary opacities, despite 72 hours of treatment with broad-spectrum antibiotics. Thus, a diagnostic bronchoscopy with bronchoalveolar lavage (BAL) was performed. BAL cell count and differential revealed 363 nucleated cells/µL, with profound eosinophilia (42% eosinophils, 44% macrophages, 14% neutrophils).

Bacterial and fungal cultures and a viral polymerase chain reaction panel were negative. HIV antibody-antigen and RNA testing were also negative. The patient had no evidence or history of underlying malignancy, autoimmune disease, or recent immunosuppressive therapy, including corticosteroids. Due to consistent imaging findings and lack of improvement with appropriate treatment for bacterial pneumonia, further work-up was pursued.

THE DIAGNOSIS

Given the consistent radiographic pattern, the differential diagnosis for this patient included pneumocystis pneumonia (PCP), a potentially life-threatening opportunistic infection. Work-up therefore included direct fluorescent antibody testing, which was positive for Pneumocystis jirovecii, a fungus that can cause PCP.

Of note, the patient’s white blood cell count was elevated on admission (11.44 × 10³/µL) but low for much of his hospital stay (nadir = 1.97 × 10³/µL), with associated lymphopenia (nadir = 0.22 × 10³/µl). No peripheral eosinophilia was noted.

Continue to: DISCUSSION

 

 

DISCUSSION

PCP typically occurs in immunocompromised individuals and may be related to HIV infection, malignancy, or exposure to immunosuppressive therapies.^1,2 While rare cases of PCP have been described in adults without predisposing factors, many of these cases occurred at the beginning of the AIDS epidemic, prior to reliable HIV testing.^3-5

Uncharted territory. We were confident in our diagnosis because immunofluorescence testing has very few false-positives and a high specificity.^6-8 But there were informational gaps. The eosinophilia recorded on BAL is poorly described in HIV-negative patients with PCP but well-described in HIV-positive patients, with the level of eosinophilia associated with disease severity.^9,10 Eosinophils are thought to contribute to pulmonary inflammation, which may explain the severity of our patient’s course.¹⁰

A first of its kind case?

To our knowledge, this is the first report of PCP in a patient with cirrhosis from chronic hepatitis C virus infection and no other predisposing conditions or preceding immunosuppressive therapy. We suspect that his lymphopenia, which was noted during his critical illness, predisposed him to PCP.

Individuals with lymphopenia and low CD4+ T-cell counts have been shown to be at increased risk of pneumocystis pneumonia.

Lymphocytes (in particular CD4+ T cells) have been shown to play an important role, along with alveolar macrophages and neutrophils, in directing the host defense against P jirovecii infection.^1,3,11 Individuals with lymphopenia and low CD4+ T-cell counts have been shown to be at increased risk of PCP; risk increases markedly with CD4+ T cells below 200 cells/µL.^11-13

Typical risk factors for lymphopenia had not been observed in this patient. However, cirrhosis has been associated with low CD4+ T-cell counts and disruption of cell-mediated immunity, even in HIV-­seronegative patients.^14,15 There are several postulated mechanisms for low CD4+ T-cell counts in cirrhosis, including splenic sequestration, impaired T-cell production (due to impaired thymopoiesis), increased T-cell consumption, and apoptosis (due to persistent immune system activation from bacterial translocation and an overall pro-infl­ammatory state).^16,17

Continue to: Predisposing factors guide treatment

 

 

Predisposing factors guide treatment

Routine treatment for PCP in patients without HIV is a 21-day course of trimethoprim/­sulfamethoxazole (Bactrim). Dosing for patients with normal renal function is 15 to 20 mg/kg orally or intravenously per day. Patients with allergy to trimethoprim/sulfamethoxazole should ideally undergo desensitization, given its effectiveness against PCP.

Due to a sulfonamide allergy, our patient was started on primaquine 30 mg/d, clindamycin 600 mg tid, and prednisone 40 mg bid. (The corticosteroid was added because of the severity of the disease.) Three days after starting treatment—and 10 days into his hospital stay—the patient had significant improvement in his respiratory status and was successfully extubated. He underwent trimethoprim/sulfamethoxazole desensitization and completed a 21-day course of treatment for PCP with complete resolution of respiratory symptoms. Follow-up chest radiograph 2 months later (FIGURE 2) confirmed clearance of opacities.

THE TAKEAWAY

PCP remains a rare disease in patients without the typical immunosuppressive risk factors. However, it should be considered in patients with cirrhosis who develop respiratory failure, especially those with compatible radiographic findings and negative microbiologic evaluation for other, more typical, organisms.

CORRESPONDENCE
Tyler Albert, MD, VA Puget Sound Healthcare System, 1660 South Columbian Way, S-111-Pulm, Seattle, WA 98108; talbert@uw.edu

THE CASE

A 52-year-old man presented to the emergency department after vomiting a large volume of blood and was admitted to the intensive care unit. His past medical history was remarkable for untreated chronic hepatitis C resulting from injection drug use and cirrhosis without prior history of esophageal varices.

Due to ongoing hematemesis, he was intubated for airway protection and underwent esophagogastroduodenoscopy with banding of large esophageal varices on hospital day (HD) 1. He was extubated on HD 2 after clinical stability was achieved; however, he became encephalopathic over the subsequent days despite treatment with lactulose. On HD 4, the patient required re-intubation for progressive respiratory failure. Chest imaging revealed a large, simple-appearing right pleural effusion and extensive bilateral patchy ground-glass opacities (FIGURE 1).

Thoracentesis was ordered and revealed transudative pleural fluid; this finding, along with negative infectious studies, was consistent with hepatic hydrothorax. In the setting of initial decompensation, empiric treatment with vancomycin and meropenem was started for suspected hospital-acquired pneumonia.

The patient had persistent fevers that had developed during his hospital stay and pulmonary opacities, despite 72 hours of treatment with broad-spectrum antibiotics. Thus, a diagnostic bronchoscopy with bronchoalveolar lavage (BAL) was performed. BAL cell count and differential revealed 363 nucleated cells/µL, with profound eosinophilia (42% eosinophils, 44% macrophages, 14% neutrophils).

Bacterial and fungal cultures and a viral polymerase chain reaction panel were negative. HIV antibody-antigen and RNA testing were also negative. The patient had no evidence or history of underlying malignancy, autoimmune disease, or recent immunosuppressive therapy, including corticosteroids. Due to consistent imaging findings and lack of improvement with appropriate treatment for bacterial pneumonia, further work-up was pursued.

THE DIAGNOSIS

Given the consistent radiographic pattern, the differential diagnosis for this patient included pneumocystis pneumonia (PCP), a potentially life-threatening opportunistic infection. Work-up therefore included direct fluorescent antibody testing, which was positive for Pneumocystis jirovecii, a fungus that can cause PCP.

Of note, the patient’s white blood cell count was elevated on admission (11.44 × 10³/µL) but low for much of his hospital stay (nadir = 1.97 × 10³/µL), with associated lymphopenia (nadir = 0.22 × 10³/µl). No peripheral eosinophilia was noted.

Continue to: DISCUSSION

 

 

DISCUSSION

PCP typically occurs in immunocompromised individuals and may be related to HIV infection, malignancy, or exposure to immunosuppressive therapies.^1,2 While rare cases of PCP have been described in adults without predisposing factors, many of these cases occurred at the beginning of the AIDS epidemic, prior to reliable HIV testing.^3-5

Uncharted territory. We were confident in our diagnosis because immunofluorescence testing has very few false-positives and a high specificity.^6-8 But there were informational gaps. The eosinophilia recorded on BAL is poorly described in HIV-negative patients with PCP but well-described in HIV-positive patients, with the level of eosinophilia associated with disease severity.^9,10 Eosinophils are thought to contribute to pulmonary inflammation, which may explain the severity of our patient’s course.¹⁰

A first of its kind case?

To our knowledge, this is the first report of PCP in a patient with cirrhosis from chronic hepatitis C virus infection and no other predisposing conditions or preceding immunosuppressive therapy. We suspect that his lymphopenia, which was noted during his critical illness, predisposed him to PCP.

Individuals with lymphopenia and low CD4+ T-cell counts have been shown to be at increased risk of pneumocystis pneumonia.

Lymphocytes (in particular CD4+ T cells) have been shown to play an important role, along with alveolar macrophages and neutrophils, in directing the host defense against P jirovecii infection.^1,3,11 Individuals with lymphopenia and low CD4+ T-cell counts have been shown to be at increased risk of PCP; risk increases markedly with CD4+ T cells below 200 cells/µL.^11-13

Typical risk factors for lymphopenia had not been observed in this patient. However, cirrhosis has been associated with low CD4+ T-cell counts and disruption of cell-mediated immunity, even in HIV-­seronegative patients.^14,15 There are several postulated mechanisms for low CD4+ T-cell counts in cirrhosis, including splenic sequestration, impaired T-cell production (due to impaired thymopoiesis), increased T-cell consumption, and apoptosis (due to persistent immune system activation from bacterial translocation and an overall pro-infl­ammatory state).^16,17

Continue to: Predisposing factors guide treatment

 

 

Predisposing factors guide treatment

Routine treatment for PCP in patients without HIV is a 21-day course of trimethoprim/­sulfamethoxazole (Bactrim). Dosing for patients with normal renal function is 15 to 20 mg/kg orally or intravenously per day. Patients with allergy to trimethoprim/sulfamethoxazole should ideally undergo desensitization, given its effectiveness against PCP.

Due to a sulfonamide allergy, our patient was started on primaquine 30 mg/d, clindamycin 600 mg tid, and prednisone 40 mg bid. (The corticosteroid was added because of the severity of the disease.) Three days after starting treatment—and 10 days into his hospital stay—the patient had significant improvement in his respiratory status and was successfully extubated. He underwent trimethoprim/sulfamethoxazole desensitization and completed a 21-day course of treatment for PCP with complete resolution of respiratory symptoms. Follow-up chest radiograph 2 months later (FIGURE 2) confirmed clearance of opacities.

THE TAKEAWAY

PCP remains a rare disease in patients without the typical immunosuppressive risk factors. However, it should be considered in patients with cirrhosis who develop respiratory failure, especially those with compatible radiographic findings and negative microbiologic evaluation for other, more typical, organisms.

CORRESPONDENCE
Tyler Albert, MD, VA Puget Sound Healthcare System, 1660 South Columbian Way, S-111-Pulm, Seattle, WA 98108; talbert@uw.edu

Historically, aspergillosis in patients with hematopoietic stem cell transplantation (HSCT) has carried a high mortality rate. However, recent data demonstrate a dramatic improvement in outcomes for patients with HSCT: 90-day survival increased from 22% before 2000 to 45% over the past 15 years.¹ Improved outcomes coincide with changes in transplant immunosuppression practices, use of cross-sectional imaging for early disease identification, galactomannan screening, and the development of novel treatment options.

Voriconazole is an azole drug that blocks the synthesis of ergosterol, a vital component of the cellular membrane of fungi. Voriconazole was approved in 2002 after a clinical trial demonstrated an improvement in 50% of patients with invasive aspergillosis in the voriconazole arm vs 30% in the amphotericin B arm at 12 weeks.² Amphotericin B is a polyene antifungal drug that binds with ergosterol, creating leaks in the cell membrane that lead to cellular demise. Voriconazole quickly became the first-line therapy for invasive aspergillosis and is recommended by both the Infectious Disease Society of American (IDSA) and the European Conference on Infections in Leukemia.³

Case Presentation

A 55-year-old man with high-risk chronic myelogenous leukemia (CML) underwent a 10 of 10 human leukocyte antigen allele and antigen-matched peripheral blood allogeneic HSCT with a myeloablative-conditioning regimen of busulfan and cyclophosphamide, along with prophylactic voriconazole, sulfamethoxazole/trimethoprim, and acyclovir. After successful engraftment (without significant neutropenia), his posttransplant course was complicated by grade 2 graft vs host disease (GVHD) of the skin, eyes, and liver, which responded well to steroids and tacrolimus. Voriconazole was continued for 5 months until immunosuppression was minimized (tacrolimus 1 mg twice daily). Two months later, the patient’s GVHD worsened, necessitating treatment at an outside hospital with high-dose prednisone (2 mg/kg/d) and cyclosporine (300 mg twice daily). Voriconazole prophylaxis was not reinitiated at that time.

One year later, at a routine follow-up appointment, the patient endorsed several weeks of malaise, weight loss, and nonproductive cough. The patient’s immunosuppression recently had been reduced to 1 mg/kg/d of prednisone and 100 mg of cyclosporine twice daily. A chest X-ray demonstrated multiple pulmonary nodules; follow-up chest computed tomography (CT) confirmed multiple nodular infiltrates with surrounding ground-glass opacities suspicious with a fungal infection (Figure 1). 

Bronchoscopy with bronchoalveolar lavage (BAL) was significant for a positive Aspergillus fumigatus (A fumigatus) DNA polymerase chain reaction (PCR) assay and a BAL galactomannan level of > 5.3 optical density index (ODI) (normal, < 0.5). Bacterial and fungal cultures were negative, and serum galactomannan testing was not performed.

Treatment with oral voriconazole (300 mg twice daily) was initiated for probable pulmonary aspergillosis. Cyclosporine (150 mg twice daily) and prednisone (1 mg/kg/d) were continued throughout treatment out of concern for hepatic GVHD. The patient’s symptoms improved over the next 10 days, and follow-up chest imaging demonstrated improvement.

Two weeks after initiation of voriconazole treatment, the patient developed a new productive cough and dyspnea, associated with fevers and chills. Repeat imaging revealed right lower-lobe pneumonia. The serum voriconazole trough level was checked and was 3.1 mg/L, suggesting therapeutic dosing. The patient subsequently developed acute respiratory distress syndrome and required intubation and mechanical ventilation. Repeat BAL sampling demonstrated multidrug-resistant Escherichia coli, a BAL galactomannan level of 2.0 ODI, and negative fungal cultures. The patient’s hospital course was complicated by profound hypoxemia, requiring prone positioning and neuromuscular blockade. He was treated with meropenem and voriconazole. His immunosuppression was reduced, but he rapidly developed acute liver injury from hepatic GVHD that resolved after reinitiation of cyclosporine and prednisone at 0.75 mg/kg/d.

The patient improved over the next 3 weeks and was successfully extubated. Repeat chest CT imaging demonstrated numerous pneumatoceles in the location of previous nodules, consistent with healing necrotic fungal disease, and a new right lower-lobe cavitary mass (Figure 2). Two days after transferring out of the intensive care unit, the patient again developed hypoxemia and fevers to 39° C. Bronchoscopy with BAL of the right lower lobe revealed positive A fumigatus and Rhizopus sp polymerase chain reaction (PCR) assays, although fungal cultures were positive only for A fumigatus. Liposomal amphotericin B (5 mg/kg) was added to voriconazole therapy to treat mucormycosis and to provide a second active agent against A fumigatus.

Unfortunately, the patient’s clinical status continued to deteriorate with signs of progressive respiratory failure and infection despite empiric, broad-spectrum antibiotics and dual antifungal therapy. His serum voriconazole level continued to be therapeutic at 1.9 mg/L. The patient declined reintubation and invasive mechanical ventilation, and he ultimately transitioned to comfort measures and died with his family at the bedside.

Autopsy demonstrated widely disseminated Aspergillus infection as the cause of death, with evidence of myocardial, neural, and vascular invasion of A fumigatus (Figures 3 and 4). 

Rhizopus sp was identified in the large right lower lobe cavity without signs of angioinvasion, suggestive of cavity colonization. Follow-up sensitivity data (University of Texas, San Antonio, CLSI M38 A2, broth microdilution) of the A fumigatus demonstrated voriconazole sensitivity (MIC 0.25 µg/dL) but surprisingly, amphotericin B resistance (MIC > 2 µg/dL).

 

Discussion

This case of fatal, progressive, invasive, pulmonary aspergillosis demonstrates several important factors in the treatment of patients with this disease. Treatment failure usually relates to any of 4 possible factors: host immune status, severity or burden of disease, appropriate dosing of antifungal agents, and drug resistance. This patient’s immune system was heavily suppressed for a prolonged period. Attempts at reducing immunosuppression to the minimal required dosage to prevent a GVHD flare were unsuccessful and became an unmodifiable risk factor, a major contributor to his demise.

The risks of continuous high-dose immunosuppression in steroid-refractory GVHD is well understood and has been previously demonstrated to have up to 50% 4-year nonrelapse mortality, mainly due to overwhelming bacterial, viral, and fungal infections.⁴ All attempts should be made to cease or reduce immunosuppression in the setting of a severe infection, although this is sometimes impossible as in this case.

The patient’s disease burden was significant as evidenced by the bilateral, multifocal pulmonary nodules seen on chest imaging and the disseminated disease found at postmortem examination. His initial improvement in symptoms with voriconazole and the evolution of his images (with many of his initial pulmonary nodules becoming pneumatoceles) suggested a temporary positive immune response. The authors believe that the Rhizopus in his sputum represents noninvasive colonization of one of his pneumatoceles, because postmortem examination failed to reveal Rhizopus at any other location.

Voriconazole has excellent pulmonary and central nervous system penetration: In this patient serum levels were well within the therapeutic range. His peculiar drug resistance pattern (sensitivity to azoles and resistance to amphotericin) is unusual. Azole resistance in leukemia and patients with HSCT is more common than is amphotericin resistance, with current estimates of azole resistance close to 5%, ranging between 1% and 30%.^5,6 Widespread use of antifungal prophylaxis with azoles likely selects for azole resistance.⁶

Despite this concern of azole resistance, current IDSA guidelines recommend against routine susceptibility testing of Aspergillus to azole therapy because of the current lack of consensus between the European Committee on Antibiotic Susceptibility Testing and Clinical and Laboratory Standards Institute on break points for resistance patterns.^3,7 This is an area of emerging research, and proposed cut points for declaration of resistance do exist in the literature even if not globally agreed on.⁸

Combination antifungal therapy is an option for treatment in cases of possible drug resistance. Nonetheless, a recent randomized, double-blind, placebo-controlled, multicenter trial comparing voriconazole monotherapy with the combination of voriconazole and anidulafungin failed to demonstrate an overall mortality benefit in the primary analysis, although secondary analysis showed a mortality benefit with combination therapy in patients at highest risk for death.⁹

Despite the lack of unified standards with susceptibility testing, it may be reasonable to perform such tests in patients with demonstrating progressive disease. In this patient’s case, amphotericin B was added to treat the Rhizopus species found in his sputum, and while not the combination studied in the previously mentioned study, the drug should have provided an additional active agent for Aspergillus should this patient have had azole resistance.

Surprisingly, subsequent testing demonstrated the Aspergillus species to be resistant to amphotericin B. De novo amphotericin B-resistant A fumigates is extremely rare, with an expected incidence of 1% or less.¹⁰ The authors believe the patient may have demonstrated induction of amphotericin-B resistance through activation of fungal stress pathways by prior treatment with voriconazole. This has been demonstrated in vitro and should be considered should combination salvage therapy be required for the treatment of a refractory Aspergillus infection especially if patients have received prior treatment with voriconazole.¹¹

 

Conclusion

This fatal case of invasive pulmonary aspergillosis illustrates the importance of considering the 4 main causes of treatment failure in an infection. Although the patient had a high burden of disease with a rare resistance pattern, he was treated with appropriate and well-dosed therapy. Ultimately, his unmodifiable immunosuppression was likely the driving factor leading to treatment failure and death. The indication for and number of bone marrow transplants continues to increase, thus exposure to and treatment of invasive fungal infections will increase accordingly. As such, providers should ensure that all causes of treatment failure are considered and addressed.

Historically, aspergillosis in patients with hematopoietic stem cell transplantation (HSCT) has carried a high mortality rate. However, recent data demonstrate a dramatic improvement in outcomes for patients with HSCT: 90-day survival increased from 22% before 2000 to 45% over the past 15 years.¹ Improved outcomes coincide with changes in transplant immunosuppression practices, use of cross-sectional imaging for early disease identification, galactomannan screening, and the development of novel treatment options.

Voriconazole is an azole drug that blocks the synthesis of ergosterol, a vital component of the cellular membrane of fungi. Voriconazole was approved in 2002 after a clinical trial demonstrated an improvement in 50% of patients with invasive aspergillosis in the voriconazole arm vs 30% in the amphotericin B arm at 12 weeks.² Amphotericin B is a polyene antifungal drug that binds with ergosterol, creating leaks in the cell membrane that lead to cellular demise. Voriconazole quickly became the first-line therapy for invasive aspergillosis and is recommended by both the Infectious Disease Society of American (IDSA) and the European Conference on Infections in Leukemia.³

Case Presentation

A 55-year-old man with high-risk chronic myelogenous leukemia (CML) underwent a 10 of 10 human leukocyte antigen allele and antigen-matched peripheral blood allogeneic HSCT with a myeloablative-conditioning regimen of busulfan and cyclophosphamide, along with prophylactic voriconazole, sulfamethoxazole/trimethoprim, and acyclovir. After successful engraftment (without significant neutropenia), his posttransplant course was complicated by grade 2 graft vs host disease (GVHD) of the skin, eyes, and liver, which responded well to steroids and tacrolimus. Voriconazole was continued for 5 months until immunosuppression was minimized (tacrolimus 1 mg twice daily). Two months later, the patient’s GVHD worsened, necessitating treatment at an outside hospital with high-dose prednisone (2 mg/kg/d) and cyclosporine (300 mg twice daily). Voriconazole prophylaxis was not reinitiated at that time.

One year later, at a routine follow-up appointment, the patient endorsed several weeks of malaise, weight loss, and nonproductive cough. The patient’s immunosuppression recently had been reduced to 1 mg/kg/d of prednisone and 100 mg of cyclosporine twice daily. A chest X-ray demonstrated multiple pulmonary nodules; follow-up chest computed tomography (CT) confirmed multiple nodular infiltrates with surrounding ground-glass opacities suspicious with a fungal infection (Figure 1). 

Bronchoscopy with bronchoalveolar lavage (BAL) was significant for a positive Aspergillus fumigatus (A fumigatus) DNA polymerase chain reaction (PCR) assay and a BAL galactomannan level of > 5.3 optical density index (ODI) (normal, < 0.5). Bacterial and fungal cultures were negative, and serum galactomannan testing was not performed.

Treatment with oral voriconazole (300 mg twice daily) was initiated for probable pulmonary aspergillosis. Cyclosporine (150 mg twice daily) and prednisone (1 mg/kg/d) were continued throughout treatment out of concern for hepatic GVHD. The patient’s symptoms improved over the next 10 days, and follow-up chest imaging demonstrated improvement.

Two weeks after initiation of voriconazole treatment, the patient developed a new productive cough and dyspnea, associated with fevers and chills. Repeat imaging revealed right lower-lobe pneumonia. The serum voriconazole trough level was checked and was 3.1 mg/L, suggesting therapeutic dosing. The patient subsequently developed acute respiratory distress syndrome and required intubation and mechanical ventilation. Repeat BAL sampling demonstrated multidrug-resistant Escherichia coli, a BAL galactomannan level of 2.0 ODI, and negative fungal cultures. The patient’s hospital course was complicated by profound hypoxemia, requiring prone positioning and neuromuscular blockade. He was treated with meropenem and voriconazole. His immunosuppression was reduced, but he rapidly developed acute liver injury from hepatic GVHD that resolved after reinitiation of cyclosporine and prednisone at 0.75 mg/kg/d.

The patient improved over the next 3 weeks and was successfully extubated. Repeat chest CT imaging demonstrated numerous pneumatoceles in the location of previous nodules, consistent with healing necrotic fungal disease, and a new right lower-lobe cavitary mass (Figure 2). Two days after transferring out of the intensive care unit, the patient again developed hypoxemia and fevers to 39° C. Bronchoscopy with BAL of the right lower lobe revealed positive A fumigatus and Rhizopus sp polymerase chain reaction (PCR) assays, although fungal cultures were positive only for A fumigatus. Liposomal amphotericin B (5 mg/kg) was added to voriconazole therapy to treat mucormycosis and to provide a second active agent against A fumigatus.

Unfortunately, the patient’s clinical status continued to deteriorate with signs of progressive respiratory failure and infection despite empiric, broad-spectrum antibiotics and dual antifungal therapy. His serum voriconazole level continued to be therapeutic at 1.9 mg/L. The patient declined reintubation and invasive mechanical ventilation, and he ultimately transitioned to comfort measures and died with his family at the bedside.

Autopsy demonstrated widely disseminated Aspergillus infection as the cause of death, with evidence of myocardial, neural, and vascular invasion of A fumigatus (Figures 3 and 4). 

Rhizopus sp was identified in the large right lower lobe cavity without signs of angioinvasion, suggestive of cavity colonization. Follow-up sensitivity data (University of Texas, San Antonio, CLSI M38 A2, broth microdilution) of the A fumigatus demonstrated voriconazole sensitivity (MIC 0.25 µg/dL) but surprisingly, amphotericin B resistance (MIC > 2 µg/dL).

 

Discussion

This case of fatal, progressive, invasive, pulmonary aspergillosis demonstrates several important factors in the treatment of patients with this disease. Treatment failure usually relates to any of 4 possible factors: host immune status, severity or burden of disease, appropriate dosing of antifungal agents, and drug resistance. This patient’s immune system was heavily suppressed for a prolonged period. Attempts at reducing immunosuppression to the minimal required dosage to prevent a GVHD flare were unsuccessful and became an unmodifiable risk factor, a major contributor to his demise.

The risks of continuous high-dose immunosuppression in steroid-refractory GVHD is well understood and has been previously demonstrated to have up to 50% 4-year nonrelapse mortality, mainly due to overwhelming bacterial, viral, and fungal infections.⁴ All attempts should be made to cease or reduce immunosuppression in the setting of a severe infection, although this is sometimes impossible as in this case.

The patient’s disease burden was significant as evidenced by the bilateral, multifocal pulmonary nodules seen on chest imaging and the disseminated disease found at postmortem examination. His initial improvement in symptoms with voriconazole and the evolution of his images (with many of his initial pulmonary nodules becoming pneumatoceles) suggested a temporary positive immune response. The authors believe that the Rhizopus in his sputum represents noninvasive colonization of one of his pneumatoceles, because postmortem examination failed to reveal Rhizopus at any other location.

Voriconazole has excellent pulmonary and central nervous system penetration: In this patient serum levels were well within the therapeutic range. His peculiar drug resistance pattern (sensitivity to azoles and resistance to amphotericin) is unusual. Azole resistance in leukemia and patients with HSCT is more common than is amphotericin resistance, with current estimates of azole resistance close to 5%, ranging between 1% and 30%.^5,6 Widespread use of antifungal prophylaxis with azoles likely selects for azole resistance.⁶

Despite this concern of azole resistance, current IDSA guidelines recommend against routine susceptibility testing of Aspergillus to azole therapy because of the current lack of consensus between the European Committee on Antibiotic Susceptibility Testing and Clinical and Laboratory Standards Institute on break points for resistance patterns.^3,7 This is an area of emerging research, and proposed cut points for declaration of resistance do exist in the literature even if not globally agreed on.⁸

Combination antifungal therapy is an option for treatment in cases of possible drug resistance. Nonetheless, a recent randomized, double-blind, placebo-controlled, multicenter trial comparing voriconazole monotherapy with the combination of voriconazole and anidulafungin failed to demonstrate an overall mortality benefit in the primary analysis, although secondary analysis showed a mortality benefit with combination therapy in patients at highest risk for death.⁹

Despite the lack of unified standards with susceptibility testing, it may be reasonable to perform such tests in patients with demonstrating progressive disease. In this patient’s case, amphotericin B was added to treat the Rhizopus species found in his sputum, and while not the combination studied in the previously mentioned study, the drug should have provided an additional active agent for Aspergillus should this patient have had azole resistance.

Surprisingly, subsequent testing demonstrated the Aspergillus species to be resistant to amphotericin B. De novo amphotericin B-resistant A fumigates is extremely rare, with an expected incidence of 1% or less.¹⁰ The authors believe the patient may have demonstrated induction of amphotericin-B resistance through activation of fungal stress pathways by prior treatment with voriconazole. This has been demonstrated in vitro and should be considered should combination salvage therapy be required for the treatment of a refractory Aspergillus infection especially if patients have received prior treatment with voriconazole.¹¹

 

Conclusion

This fatal case of invasive pulmonary aspergillosis illustrates the importance of considering the 4 main causes of treatment failure in an infection. Although the patient had a high burden of disease with a rare resistance pattern, he was treated with appropriate and well-dosed therapy. Ultimately, his unmodifiable immunosuppression was likely the driving factor leading to treatment failure and death. The indication for and number of bone marrow transplants continues to increase, thus exposure to and treatment of invasive fungal infections will increase accordingly. As such, providers should ensure that all causes of treatment failure are considered and addressed.

Historically, aspergillosis in patients with hematopoietic stem cell transplantation (HSCT) has carried a high mortality rate. However, recent data demonstrate a dramatic improvement in outcomes for patients with HSCT: 90-day survival increased from 22% before 2000 to 45% over the past 15 years.¹ Improved outcomes coincide with changes in transplant immunosuppression practices, use of cross-sectional imaging for early disease identification, galactomannan screening, and the development of novel treatment options.

Voriconazole is an azole drug that blocks the synthesis of ergosterol, a vital component of the cellular membrane of fungi. Voriconazole was approved in 2002 after a clinical trial demonstrated an improvement in 50% of patients with invasive aspergillosis in the voriconazole arm vs 30% in the amphotericin B arm at 12 weeks.² Amphotericin B is a polyene antifungal drug that binds with ergosterol, creating leaks in the cell membrane that lead to cellular demise. Voriconazole quickly became the first-line therapy for invasive aspergillosis and is recommended by both the Infectious Disease Society of American (IDSA) and the European Conference on Infections in Leukemia.³

Case Presentation

A 55-year-old man with high-risk chronic myelogenous leukemia (CML) underwent a 10 of 10 human leukocyte antigen allele and antigen-matched peripheral blood allogeneic HSCT with a myeloablative-conditioning regimen of busulfan and cyclophosphamide, along with prophylactic voriconazole, sulfamethoxazole/trimethoprim, and acyclovir. After successful engraftment (without significant neutropenia), his posttransplant course was complicated by grade 2 graft vs host disease (GVHD) of the skin, eyes, and liver, which responded well to steroids and tacrolimus. Voriconazole was continued for 5 months until immunosuppression was minimized (tacrolimus 1 mg twice daily). Two months later, the patient’s GVHD worsened, necessitating treatment at an outside hospital with high-dose prednisone (2 mg/kg/d) and cyclosporine (300 mg twice daily). Voriconazole prophylaxis was not reinitiated at that time.

One year later, at a routine follow-up appointment, the patient endorsed several weeks of malaise, weight loss, and nonproductive cough. The patient’s immunosuppression recently had been reduced to 1 mg/kg/d of prednisone and 100 mg of cyclosporine twice daily. A chest X-ray demonstrated multiple pulmonary nodules; follow-up chest computed tomography (CT) confirmed multiple nodular infiltrates with surrounding ground-glass opacities suspicious with a fungal infection (Figure 1). 

Bronchoscopy with bronchoalveolar lavage (BAL) was significant for a positive Aspergillus fumigatus (A fumigatus) DNA polymerase chain reaction (PCR) assay and a BAL galactomannan level of > 5.3 optical density index (ODI) (normal, < 0.5). Bacterial and fungal cultures were negative, and serum galactomannan testing was not performed.

Treatment with oral voriconazole (300 mg twice daily) was initiated for probable pulmonary aspergillosis. Cyclosporine (150 mg twice daily) and prednisone (1 mg/kg/d) were continued throughout treatment out of concern for hepatic GVHD. The patient’s symptoms improved over the next 10 days, and follow-up chest imaging demonstrated improvement.

Two weeks after initiation of voriconazole treatment, the patient developed a new productive cough and dyspnea, associated with fevers and chills. Repeat imaging revealed right lower-lobe pneumonia. The serum voriconazole trough level was checked and was 3.1 mg/L, suggesting therapeutic dosing. The patient subsequently developed acute respiratory distress syndrome and required intubation and mechanical ventilation. Repeat BAL sampling demonstrated multidrug-resistant Escherichia coli, a BAL galactomannan level of 2.0 ODI, and negative fungal cultures. The patient’s hospital course was complicated by profound hypoxemia, requiring prone positioning and neuromuscular blockade. He was treated with meropenem and voriconazole. His immunosuppression was reduced, but he rapidly developed acute liver injury from hepatic GVHD that resolved after reinitiation of cyclosporine and prednisone at 0.75 mg/kg/d.

The patient improved over the next 3 weeks and was successfully extubated. Repeat chest CT imaging demonstrated numerous pneumatoceles in the location of previous nodules, consistent with healing necrotic fungal disease, and a new right lower-lobe cavitary mass (Figure 2). Two days after transferring out of the intensive care unit, the patient again developed hypoxemia and fevers to 39° C. Bronchoscopy with BAL of the right lower lobe revealed positive A fumigatus and Rhizopus sp polymerase chain reaction (PCR) assays, although fungal cultures were positive only for A fumigatus. Liposomal amphotericin B (5 mg/kg) was added to voriconazole therapy to treat mucormycosis and to provide a second active agent against A fumigatus.

Unfortunately, the patient’s clinical status continued to deteriorate with signs of progressive respiratory failure and infection despite empiric, broad-spectrum antibiotics and dual antifungal therapy. His serum voriconazole level continued to be therapeutic at 1.9 mg/L. The patient declined reintubation and invasive mechanical ventilation, and he ultimately transitioned to comfort measures and died with his family at the bedside.

Autopsy demonstrated widely disseminated Aspergillus infection as the cause of death, with evidence of myocardial, neural, and vascular invasion of A fumigatus (Figures 3 and 4). 

Rhizopus sp was identified in the large right lower lobe cavity without signs of angioinvasion, suggestive of cavity colonization. Follow-up sensitivity data (University of Texas, San Antonio, CLSI M38 A2, broth microdilution) of the A fumigatus demonstrated voriconazole sensitivity (MIC 0.25 µg/dL) but surprisingly, amphotericin B resistance (MIC > 2 µg/dL).

 

Discussion

This case of fatal, progressive, invasive, pulmonary aspergillosis demonstrates several important factors in the treatment of patients with this disease. Treatment failure usually relates to any of 4 possible factors: host immune status, severity or burden of disease, appropriate dosing of antifungal agents, and drug resistance. This patient’s immune system was heavily suppressed for a prolonged period. Attempts at reducing immunosuppression to the minimal required dosage to prevent a GVHD flare were unsuccessful and became an unmodifiable risk factor, a major contributor to his demise.

The risks of continuous high-dose immunosuppression in steroid-refractory GVHD is well understood and has been previously demonstrated to have up to 50% 4-year nonrelapse mortality, mainly due to overwhelming bacterial, viral, and fungal infections.⁴ All attempts should be made to cease or reduce immunosuppression in the setting of a severe infection, although this is sometimes impossible as in this case.

The patient’s disease burden was significant as evidenced by the bilateral, multifocal pulmonary nodules seen on chest imaging and the disseminated disease found at postmortem examination. His initial improvement in symptoms with voriconazole and the evolution of his images (with many of his initial pulmonary nodules becoming pneumatoceles) suggested a temporary positive immune response. The authors believe that the Rhizopus in his sputum represents noninvasive colonization of one of his pneumatoceles, because postmortem examination failed to reveal Rhizopus at any other location.

Voriconazole has excellent pulmonary and central nervous system penetration: In this patient serum levels were well within the therapeutic range. His peculiar drug resistance pattern (sensitivity to azoles and resistance to amphotericin) is unusual. Azole resistance in leukemia and patients with HSCT is more common than is amphotericin resistance, with current estimates of azole resistance close to 5%, ranging between 1% and 30%.^5,6 Widespread use of antifungal prophylaxis with azoles likely selects for azole resistance.⁶

Despite this concern of azole resistance, current IDSA guidelines recommend against routine susceptibility testing of Aspergillus to azole therapy because of the current lack of consensus between the European Committee on Antibiotic Susceptibility Testing and Clinical and Laboratory Standards Institute on break points for resistance patterns.^3,7 This is an area of emerging research, and proposed cut points for declaration of resistance do exist in the literature even if not globally agreed on.⁸

Combination antifungal therapy is an option for treatment in cases of possible drug resistance. Nonetheless, a recent randomized, double-blind, placebo-controlled, multicenter trial comparing voriconazole monotherapy with the combination of voriconazole and anidulafungin failed to demonstrate an overall mortality benefit in the primary analysis, although secondary analysis showed a mortality benefit with combination therapy in patients at highest risk for death.⁹

Despite the lack of unified standards with susceptibility testing, it may be reasonable to perform such tests in patients with demonstrating progressive disease. In this patient’s case, amphotericin B was added to treat the Rhizopus species found in his sputum, and while not the combination studied in the previously mentioned study, the drug should have provided an additional active agent for Aspergillus should this patient have had azole resistance.

Surprisingly, subsequent testing demonstrated the Aspergillus species to be resistant to amphotericin B. De novo amphotericin B-resistant A fumigates is extremely rare, with an expected incidence of 1% or less.¹⁰ The authors believe the patient may have demonstrated induction of amphotericin-B resistance through activation of fungal stress pathways by prior treatment with voriconazole. This has been demonstrated in vitro and should be considered should combination salvage therapy be required for the treatment of a refractory Aspergillus infection especially if patients have received prior treatment with voriconazole.¹¹

 

Conclusion

This fatal case of invasive pulmonary aspergillosis illustrates the importance of considering the 4 main causes of treatment failure in an infection. Although the patient had a high burden of disease with a rare resistance pattern, he was treated with appropriate and well-dosed therapy. Ultimately, his unmodifiable immunosuppression was likely the driving factor leading to treatment failure and death. The indication for and number of bone marrow transplants continues to increase, thus exposure to and treatment of invasive fungal infections will increase accordingly. As such, providers should ensure that all causes of treatment failure are considered and addressed.