Abstract
BACKGROUND: This systematic review aims to determine the loads of anti-A and anti-B in plasma-containing blood products that can safely be transfused to adults. MATERIALS AND METHODS: A comprehensive literature search was performed in PubMed, including studies dating back to 1940 until January 1(st), 2023. In total 1,869 articles were screened, describing 86 cases of hemolytic transfusion reactions (HTR) due to anti-A and/or anti-B in ABO incompatible products. Publications in English were included that reported the anti-A and/or anti-B IgM and/or IgG titers in the blood products, the volume of the transfused product and the clinical and/or laboratory signs compatible with an HTR. Publications reporting HTR in patients 18 years of age or younger, HTR after infusion of immunoglobulin drug products or after transfusion of units of red blood cell concentrates were excluded. Antibody load was defined as volume of the blood product in milliliters multiplied by antibody titer, defined by arbitrary units (AU). The studies were analyzed and evaluated to determine an amount of ABO antibodies in plasma that can be used safely for transfusion purposes. RESULTS: We identified HTRs with a wide-ranging antibody content, with the lowest being a platelet product with an antibody content of 12,480 AU for both IgM and IgG. However, we could establish that a calculated cutoff of 10,000 AU for IgM as well as 30,000 AU for IgG in plasma could be considered safe for transfusion. DISCUSSION: While titer is considered the gold standard when evaluating risk for HTR, the total volume of plasma transfused is rarely considered. Here, we recommend calculating an antibody content by using a titer and plasma volume of the unit(s) intended for transfusion as a good risk mitigation strategy for reducing HTRs.