American Red Cross Pitman, New Jersey, United States
Background/Case Studies: Selective IgA deficiency is defined as decreased serum IgA with normal serum IgM and IgG levels. IgA deficiency is the most common immunodeficiency reported, occurring in 1 in 400 to 1 in 800 individuals. The majority of patients with IgA deficiency receiving transfusion are asymptomatic and do not have anti-IgA. However, patients who have absolute IgA (aIgA) deficiency, defined as an IgA concentration of < 0.05mg/dL, and have produced anti-IgA antibodies can experience hypersensitivity transfusion reactions. IgA deficient plasma and platelets are collected for this purpose. Donors with aIgA deficiency are eligible for the American Rare Donor Program (ARDP). Though IgA-deficient plasma can be provided via frozen inventory, IgA-deficient platelets and red cells are typically obtained by special recruitment. Alternatively, washed red cells and platelets may be utilized. Most blood centers do not routinely screen blood donors for IgA levels. Those found to be IgA deficient need to be confirmed with a sensitive assay before being classified as aIgA deficient. We present information on activities of the three ARDP members performing screening for IgA deficiency.
Study
Design/Methods: Blood centers shared their screening method and process as well as the results of screening over the last several years. Information on the IgA deficient donors and the number of frozen plasma units by ABO type is presented. Information expiry was also examined.
Results/Findings: The three centers are using different methods to screen donors for IgA deficiency –the commercial human Immunoglobulin Isotyping Magnetic Bead Panel (Millipore) and two lab-developed tests (Ouchterlony Immunodiffusion and ELISA). The screening programs have been in place for more than 20 years at two centers and for two years at one center. The three centers screened a total of 2258 donors in CY2022. One of the centers reported screening 34,903 donors in CY2021 and identified 75 donors (1:465) who require confirmatory testing before being classified as aIgA deficient. Across the three centers, there are 76 active aIgA deficient donors and 247 frozen plasma products of the following types (132 group A, 109 group O, 1 group B and 5 group AB). Conclusions: Currently, few blood collection centers in the USA perform screening for IgA-deficiency. There are less than one hundred active donors at the three centers with active screening programs. The supply of frozen plasma products at these centers are limited. With limited donors and frozen inventory, the ARDP is challenged to fulfill requests for IgA-deficient blood products. It would be beneficial for additional centers to institute screening programs and for centers with existing programs to increase screening. It is not clear why so few centers are screening donors; it may be due to cost and/or ongoing laboratory staffing challenges.
Importance of research: Patients with absolute IgA (aIgA) deficiency are at risk of allergic and/or anaphylactic transfusion reactions. Such patients need blood products lacking IgA. Identifying donors with aIgA deficiency and managing an inventory of frozen aIgA deficient plasma is critical to meeting the needs of these patients. This study highlights that few centers are screening for these donors, and the number of active aIgA donors is low. We hope this work will encourage centers to institute screening programs.
