An EIA method on single donor solubilized HLA antigens for the identification of anti-HLA antibodies

An enzyme immunoassay (EIA) method based on solubilized human leucocyte antigens (HLA) derived from single donor platelets is described. The EIA results on these solubilized single donor HLA antigens (SDszHLA) correlated well with the complement dependent cytotoxicity (CDC) results on the lymphocytes of the same donors and also with the panel reactivity (PRA) in CDC. A concordancy rate of 78% was found for individual HLA specificities. The EIA+/CDC- ('false positive') discrepancies were more pronounced than EIA-/CDC+ ('false negative') discrepancies and varied for the different donors. To confirm discrepancies, our method was compared with a commercial PRA-STAT EIA method (based on secreted soluble HLA antigens). The same discrepancies between CDC and PRA-STAT EIA were found and are probably due to the higher and different sensitivity (e.g. non complement fixing antibodies) of EIA methods. A SDszHLA EIA method allows the identification of HLA specificities of HLA-antisera. The possibility of using individual and selected donors for the production of SDszHLA allows the directed search for well defined HLA specificities in order to confirm anti-HLA specificities found in other anti-HLA screening methods. An individualized HLA panel can be established with the support of blood banks that have HLA typed blood and platelet donors.