SAN ANTONIO – Although there has been a general decline in transfusion-related anaphylaxis and acute infections over time among hospitalized older adults in the United States, incidence rates for both transfusion-related acute lung injury and transfusion-associated circulatory overload have risen over the last decade, according to researchers from the Food and Drug Administration.
Dr. Mikhail Menis
Mikhail Menis, PharmD, an epidemiologist at the FDA Center for Biologics Evaluation and Research (CBER) and colleagues queried large Medicare databases to assess trends in transfusion-related adverse events among adults aged 65 years and older.
The investigators saw “substantially higher risk of all outcomes among immunocompromised beneficiaries, which could be related to higher blood use of all blood components, especially platelets, underlying conditions such as malignancies, and treatments such as chemotherapy or radiation, which need further investigation,” Dr. Menis said at the annual meeting of AABB, the group formerly known as the American Association of Blood Banks.
He reported data from a series of studies on four categories of transfusion-related events that may be life-threatening or fatal: transfusion-related anaphylaxis (TRA), transfusion-related acute lung injury (TRALI), transfusion-associated circulatory overload (TACO), and acute infection following transfusion (AIFT).
For each type of event, the researchers looked at overall incidence and the incidence by immune status, calendar year, blood components transfused, number of units transfused, age, sex, and race.
Anaphylaxis (TRA)
TRA may be caused by preformed immunoglobin E (IgE) antibodies to proteins in the plasma in transfused blood products or by preformed IgA antibodies in patients who are likely IgA deficient, Dr. Menis said.
The overall incidence of TRA among 8,833,817 inpatient transfusions stays for elderly beneficiaries from 2012 through 2018 was 7.1 per 100,000 stays. The rate was higher for immunocompromised patients, at 9.6, than it was among nonimmunocompromised patients, at 6.5.
The rates varied by every subgroup measured except immune status. Annual rates showed a downward trend, from 8.7 per 100,000 in 2012, to 5.1 in 2017 and 6.4 in 2018. The decline in occurrence may be caused by a decline in inpatient blood utilization during the study period, particularly among immunocompromised patients.
TRA rates increased with five or more units transfused. The risk was significantly reduced in the oldest group of patients versus the youngest (P less than .001), which supports the immune-based mechanism of action of anaphylaxis, Dr. Menis said.
They also found that TRA rates were substantially higher among patients who had received platelet and/or plasma transfusions, compared with patients who received only red blood cells (RBCs).
Additionally, risk for TRA was significantly higher among men than it was among women (9.3 vs. 5.4) and among white versus nonwhite patients (7.8 vs. 3.8).
The evidence suggested TRA cases are likely to be severe in this population, with inpatient mortality of 7.1%, and hospital stays of 7 days or longer in about 58% of cases, indicating the importance of TRA prevention, Dr. Menis said.
The investigators plan to perform multivariate regression analyses to assess potential risk factors, including underlying comorbidities and health histories for TRA occurrence for both the overall population and by immune status.