A 40-year-old women is evaluated for liver abnormalities. She had elevated transaminases and alkaline phosphatase. A liver ultrasound showed multiple lesions. She underwent liver biopsy, which showed granulomas. What test results, if abnormal, would be most suggestive of sarcoidosis?
A. Erythrocyte sedimentation rate
B. C-reactive protein
C. Lymphocyte count
D. Antinuclear antibodies
The correct answer here is lymphocyte count. Sarcoidosis is in just about every differential diagnosis, as it can involve every organ system. I will share with you a few pearls I have learned over 30 years of taking care of patients with sarcoidosis. Lymphocyte counts drop with active sarcoidosis. Sarcoidosis should always be part of the differential when you see lymphopenia. El Jammal et al. studied 90 patients referred for possible granulomatous hepatitis.1 Seventy-three patients had a final diagnosis of granulomatous hepatitis, and 38 of those patients had sarcoidosis. Lymphopenia had a high specificity (85.7%) for the diagnosis of sarcoidosis, with a specificity of 100% in the patients under 50 years old.
Morell and colleagues looked at whether low lymphocyte counts and low lymphocyte percentage were markers of active sarcoidosis.2 Forty patients with biopsy-proven sarcoidosis were prospectively evaluated every 6 months. A low lymphocyte count and a low lymphocyte percentage (< 20%) were detected more frequently in patients with active sarcoidosis than in the patients with asymptomatic sarcoidosis (P < .02 and P < .0001).
Dr. Douglas S. Paauw
Jones et al. looked at lymphopenia as a marker of sarcoidosis in patients presenting with uveitis.3 The study was a retrospective case-control study (112 patients with sarcoidosis-associated uveitis and 398 controls with other forms of uveitis). The mean lymphocyte count for patients with sarcoidosis was 1.43 vs. 2.04 for other causes of uveitis (P ≤ .0001).
Patients with sarcoidosis are at risk of hypercalciuria, hypercalcemia, and kidney stones. These are common in patients with sarcoidosis, with up to 50% of such patients having hypercalciuria. This is because in sarcoidosis patients 25(OH) vitamin D is converted in granulomas by activated macrophages to 1,25(OH)2 vitamin D, which is the active form of vitamin D.
Several studies have looked at the diagnostic utility of 1,25(OH)2 vitamin D levels in patients with suspected sarcoidosis. Rohmer and colleagues looked at whether 1,25(OH)2 vitamin D levels could help with the diagnosis of sarcoidosis as the cause of uveitis.4 They found that the level of 25(OH) vitamin D in sarcoidosis patients with uveitis was lower than in patients with uveitis without sarcoidosis, 34 vs. 43 nmol/mL (P < .02), whereas the 1,25(OH)2 vitamin D level was higher in patients with sarcoidosis than in those with uveitis without sarcoidosis, 132 vs. 108 pmol/L (P = .02). They looked at the 1,25(OH)2D/25(OH)D ratio; a ratio > 3.5 was strongly associated with an abnormal chest CT-scan (OR = 5.7, P = .003) and granulomas on bronchial biopsy (OR = 14.7, P = .007).
Kavathia et al. looked at whether elevated 1,25(OH)2 vitamin D levels predicted chronicity of sarcoidosis.5 A total of 59 sarcoidosis patients were recruited for the study. Higher serum 1,25(OH)2 vitamin D levels were associated with patients requiring repeated systemic immunosuppressive therapy or > 1 year of therapy. Increasing quartiles of serum 1,25(OH)2 vitamin D level were associated with increased odds of patients having chronic sarcoidosis (OR = 1.82; 95% CI, 1.11-2.99, P = .019).
Because of the higher activated vitamin D levels in sarcoidosis patients, they are at risk for problems with vitamin D supplementation. I have seen two patients develop large numbers of kidney stones after receiving high-dose vitamin D. Sodhi and Aldrich reported on a cohort of 196 sarcoidosis patients who had received vitamin D and compared them with 196 control patients with sarcoidosis who were not receiving vitamin D.6 Hypercalcemia was more frequent in the group that received vitamin D (42.3%) than in the group that did not (18.3%, P < .0001). In this study, only a minority (23%) of patients receiving vitamin D had their 1,25(OH)2 vitamin D level checked.
Pearl: Lymphocyte count and 1,25(OH)2 vitamin D levels can be helpful tests in assessing sarcoidosis activity. Patients with sarcoidosis who receive vitamin D should have their 1.25(OH)2 vitamin D levels monitored.
Dr. Paauw is professor of medicine in the division of general internal medicine at the University of Washington, Seattle, and he serves as third-year medical student clerkship director at the University of Washington. Contact Dr. Paauw at dpaauw@uw.edu.
References
1. El Jammal et al. Sarcoidosis Vasc Diffuse Lung Dis. 2023 Sep 13;40(3):e2023031.
2. Morell F et al. Chest. 2002 Apr;121(4):1239-44.
3. Jones NP et al. Br J Ophthalmol. 2016 Oct;100(10):1393-6.
4. Rohmer J et al. Ocul Immunol Inflamm. 2020 Apr 2;28(3):341-7.
5. Kavathia D et al. Respir Med. 2010 Apr;104(4):564–70.
6. Sodhi A and Aldrich T. Am J Med Sci. 2016 Sep;352(3):252-7.