PHILADELPHIA—Researchers believe a simple screening strategy could reduce the risk of transfusion-related acute lung injury (TRALI) in patients receiving apheresis platelets (APs) by about 60%.
Studying TRALI cases reported to the American Red Cross, the investigators found evidence to support the idea that testing female AP donors who report prior pregnancy and deferring those with human leukocyte antigen (HLA) antibodies could greatly decrease the risk of TRALI.
Anne Eder, MD, of the American Red Cross in Rockville, Maryland, presented this research at the AABB Annual Meeting 2014 (abstract S82-040B).
Dr Eder and her colleagues assessed cases of TRALI and possible TRALI reported to the American Red Cross’s national hemovigilance program. The researchers compared the incidence of TRALI according to the type of blood component transfused as well as the sex of the donor.
TRALI cases due to APs and red blood cells (RBCs) from 2006 to 2013 and male-donor-predominant plasma from 2008 to 2013 were calculated as rates per 106 distributed units.
The blood center distributed 6.6 million AP units (>70% from male donors, excluding platelet additive solution), 9.6 million plasma units (>95% from male donors), and 48.6 million RBC units (54% from male donors).
In all, there were 224 cases of TRALI, 175 among patients who received a single type of blood component within 6 hours. There were 36 TRALI cases among plasma recipients, 92 among RBC recipients, and 41 among AP recipients.
The TRALI risk was about 3-fold greater for AP recipients than for RBC recipients or recipients of male-predominant plasma. The odds ratios (ORs) were 3.2, 1.0, and 0.8, respectively. The OR for all plasma recipients (including group AB female plasma) was 2.0.
The rate of fatalities was higher for AP recipients than RBC recipients, at 0.6 per 106 and 0.2 per 106, respectively (P=0.04).
When the researchers analyzed TRALI cases according to donor, they found a nearly 6-fold predilection for female donors among AP recipients (OR=5.6) and a nearly 5-fold predilection for female donors in RBC recipients (OR=4.5).
The investigators also considered the 41 AP TRALI cases individually to assess how effective a screening program might have been for reducing the risk of TRALI.
In 12 cases, patients had received AP from a male donor. Of the 29 female donors, 26 had reported a prior pregnancy, and 2 had test results suggesting a prior pregnancy.
Of those 28 donors, 3 were negative for HLA antibodies, leaving 25 cases, or 61%, positive for HLA antibodies.
Seventeen of the female donors had HLA class I and II antibodies, including 3 whose donation resulted in a fatality. One had HLA class I only, 2 had HLA class II only, 5 had HLA I or II and a specific human neutrophil antigen (HNA) antibody, and 1 had a specific HNA antibody only.
The researchers evaluated 7 cases in which donors had HLA class I or II antibodies. And they found that all 7 had signal-to-cutoff ratios much higher than any cutoff discussed for screening donors (greater than 100).
“So we predict that a strategy to test female apheresis donors who report prior pregnancy and to defer those with HLA antibodies may reduce the risk of TRALI by about 60% and prevent cases from human neutrophil antibodies as well,” Dr Eder concluded.