Continuous Monitoring of Donor Specific Anti-HLA Antibody in Kidney Transplantation Patients

Abstract

BACKGROUND: A positive reaction at flow cytometry crossmatch (FCXM) has been highlighted by its predictive value for clinical outcome in kidney transplantation after accumulation of large clinical data. The detection of de novo development of anti-HLA antibodies after transplantation is associated with increased rejection and decreased graft survival. In this study, we report the experience for the detection of anti-donor specific antibody (DSA) by more sensitive FCXM methods in renal transplantation patients. METHODS: T and B cell FCXMs were performed on 11 pretransplant and 51 posttransplant sera from 11 patients who received renal grafts between 2004 and 2005. The posttransplant sera were collected in specific and regular intervals from posttranspant 1 week to 1 year. RESULTS: Among 62 sera, four (7.8%) from 2 patients showed positive FCXM. In one patient, pretransplant serum which was negative at previous CDCXM, and 2 consecutive sera collected at 1 week and 1 month after transplantation were positive at FCXM. And the antibody identified was B51 which was specific for one of donor alleles (DSA). In another patient, FCXM became positive 1 week after transplantation although pretransplant serum had negative results at both CDCXM and FCXM. Both patients had experienced more than one rejection episodes. CONCLUSIONS: Detection of DSA with more sensitive technique such as flow cytometry based method clearly displayed a beneficial effect for prediction of clinical outcome as a part of pretransplant compatibility test, and also as a posttransplant monitoring test to identify the de novo production of clinically significant DSA.