Association Between HLA Antibodies and Different Sensitization Events in Renal Transplant Candidates.

Abstract

Background. Human leukocyte antigen (HLA) allo-immunization is caused by variousevents such as blood transfusions, pregnancies, or organ transplantations, which can leadto sensitization. In this retrospective study, we evaluated different sensitization models andtheir effects on panel-reactive antibody (PRA) profiles of renal transplantation candidates.Methods. Anti-HLA class I/II antibody screening tests were performed in 906 renaltransplantation candidates with the use of a microbead-based assay (Luminex).Results. Two hundred ninety-seven (32.8%) of the patients were determined as positivein terms of PRA, and 609 (67.2%) were negative. Sensitized and non-sensitized patientswere compared separately in terms of each sensitization type. The anti-HLA class I, II,and IþII positivity rates in patients sensitized only by blood transfusion were 13.1%,6.3%, and 14.1%, the rates with pregnancy sensitization were 35.5%, 29%, and 45.2%,and rates with previous transplantation sensitization were 15.6%, 34.4%, and 38.9%,respectively. Prevalence of PRA positivity was significantly higher in patients withprevious pregnancy than with transplantation and transfusion (odds ratio, 1.003; 95%confidence interval, 0.441e2.281; P ¼ .031). The risk of developing HLA class Iantibodies was higher in pregnancies (P < .001), and the risk of developing anti-HLAclass II antibodies was higher in patients who had undergone a previous transplantation(P < .001). The rate of developing HLA-B antibodies in patients sensitized bypregnancy were significantly higher compared with sensitization after transfusion(P ¼ .015), as was the rate of developing HLA-DQ antibodies in patients sensitized byprevious transplantation compared with sensitization through pregnancy (P ¼ .042).Conclusions. In patients who are waiting for kidney transplantation, sensitization bypregnancy and transplantation have a significant impact on development of HLA class Iand class II antibodies.