Detection of allo- and autoantibodies in kidney transplantation by flow cytometry (original) (raw)

A LLOANTIBODIES present in the serum of kidney graft recipients and induced by prior transfusions, transplants, or pregnancies recognize antigens on the graft's surfaces that can lead to graft rejection and loss. 1,2 These alloantibodies may be directed against major histocompatibility antigens or other antigenic systems. 1,2 Recipients may also have autoantibodies whose presence is associated with a better graft acceptance. 1-5 Many techniques have been developed for allo-and autoantibodies detection. The complement-dependent cytotoxicity (CDC) crossmatches are the most commonly used. Among these are the classic NIH, 2,6 Amos, 7 and Antikappa crossmatches 8,9 and the use of DTT for differentiation of IgG and IgM antibodies. 11 The flow cytometry crossmatch (FCXM) is an indirect immunofluorescence test that offers higher reliability and sensitivity. 10 -15 It is controversial whether FCXM has a prognostic value in kidney transplantation. It has been reported that kidney graft recipients with FCXM positive and CDC negative crossmatches have increased rejection episodes and lower graft survival, compared to patients with both FCXM and CDC negative tests. [15][16][17] In high risk groups like retransplanted and multitransfused patients and women with previous pregnancies, the correlation with FCXM is more clear than for low risk patients. 19 -21 Moreover, posttransplant positivization detected by FCXM has also been associated with lower survival rates. 22,23 However, there are also reports showing no association of FCXM positivity and rejection or graft loss. The aim of this study was to evaluate the capacity of FCXM to detect alloantibodies that lead to rejection and graft loss in both cadaveric and living related kidney transplants. Our results show that the alloantibodies detected by flow cytometry are significantly associated with hyperacute and accelerated rejections.