Flow Cytometric Detection of Anti-AB Antibody Titers in Blood Group O Recipients of Blood Group A2 Donor Kidneys

Abstract Aim ABO-incompatible kidney transplantation has been accepted for end-stage renal failure patients who have no ready opportunity for a deceased or living donor. Antibody titration for ABO-incompatible renal transplantation is not only difficult but also lacks conformity among laboratories. Herein we analyzed 20 living related renal transplant couples to detect recipient anti-A2 antibody using flow cytometric analysis. Materials and methods Patients were admitted to our center for renal transplantation between January 1999 and December 2010. All but four of them had undergone a previous renal transplantation from an ABO-compatible donor but experienced graft failure. All donor blood groups were subtyped by our blood bank using a lectin-based dilution assay. To detect recipient anti-A2 antibody titers we used a tube hemagglutination method. A/B antibody titer analysis by flow cytometry incubated serially diluted serum samples with donor erythrocytes. Each analysis was repeated three times over a 2-week period using an older and the last sera simultaneously. Results The 13 male and 7 female patients showed our overall mean age of 32 ± 12 years. All patients had panel-reactive antibody levels below 15%. The level of flow cytometric antibody titers did not vary upon repeated analysis ( P = .01). When compared with the tube method there was a discrepancy of the level at which the antibody titer became negative. Discussion Flow cytometric antibody titration is a practical and rapid technique to determine the amount of anti-A2 antibody in renal recipients.