Modifying the red cell surface: towards an ABO‐universal blood supply

Abstract

SummaryEliminating the risk for ABO-incompatible transfusion errors and simplifying logistics by creating a universal blood inventory is a challenging idea. Goldstein and co-workers pioneered the field of enzymatic conversion of blood group A and B red blood cells (RBCs) to O (ECO). Using a-galactosidase from coffee beans to produce B-ECO RBCs, proof of principle for this revolutionary concept was achieved in clinical trials. However, because this enzyme has poor kinetic properties and low pH optimum the process was not economically viable. Conversion of group A RBCs was only achieved with the weak A 2 subgroup with related enzymes having acidic pH optima. More recently, the identification of entirely new families of bacterial exoglycosidases with remarkably improved kinetic properties for cleaving A and B antigens has reinvigorated the field. Enzymatic conversion of groups A, B and AB RBCs with these novel enzymes resulting in ECO RBCs typing as O can now be achieved with low enzyme protein consumption, short incubation times and at neutral pH. Presently, clinical trials evaluating safety and efficacy of ECO RBCs are ongoing. Here, we review the status of the ECO technology, its impact and potential for introduction into clinical component preparation laboratories.

The IgG-specific endoglycosidase EndoS inhibits both cellular and complement-mediated autoimmune hemolysis

“…These are now being evaluated for applications in transfusion medicine. 38,39 However, the benefit of EndoS action is the specific activity against IgG, apparently without affecting the RBC surface itself. Other endoglycosidases, such as EndoF 1-3 from Elizabethkingia meningoseptica or EndoE from Enterococcus faecalis, have activity on a broad range of glycoproteins.…”

Human RBCs blood group conversion from A to O using a novel α-N-acetylgalactosaminidase of high specific activity

“…Now the clinical trials of universal RBCs are being performed in the USA. If this technology proves successful in clinical trials, it will be of wide use in clinical transfusion in the future and there will be a great revolution [18] . Liu et al [15] used pET-28a(+) expression vector to obtain combinant αNAGA enzyme cloned from ATCC 13253, K cat /K m value of which was 127.6 (s·μmol/L) −1 .…”

Mechatronic system for performing blood pre-transfusion tests

“…Although these systems are less frequent in the population and induce the formation of antibodies to a significant lower level of intensity in comparison to the ABO and Rh systems they cause minor consequences in terms of transfusion reactions [34,35].…”