IMPAIRED RENAL GRAFT-SURVIVAL AFTER A POSITIVE B-CELL FLOW-CYTOMETRY CROSS-MATCH

Background. The clinical and immunological relevance of a positive B-c ell flow-cytometry (B-FCXM) crossmatch in renal transplantation is sti ll controversial. Methods. We retrospectively analysed 145 consecutive cadaveric renal transplantations performed from May 1991 to September 1995 in our institution. All grafts were transplanted following a neg ative IgG T-cell complement-dependent cytotoxicity crossmatch (T-CDCXM ). Concomitantly to CDCXM, B-cell and T-cell FCXM were performed and r esults were expressed as a mean fluorescence index (FI). Two groups we re compared: 116 recipients grafted with a negative B-FCXM vs a group of 19 patients grafted with a positive B-FCXM. Results. The two groups were similar for length of cold ischaemia, donor and recipient's age and degree of HLA mismatching. The proportion of patients with pre-tra nsplant anti-HLA class I antibodies or a retransplantation was signifi cantly increased in the positive B-FCXM group vs the negative B-FCXM g roup. Recipient survival at 48 months was not significantly different in the two groups. However, graft survival at 12 and 48 months was sig nificantly poorer in the positive B-FCXM than in negative B-FCXM (68% us 90% at 12 months: P=0.007, and 57% vs 79% at 48 months: P=0.02). Wi thin the positive B-FCXM group, no differences were found in pre-trans plant anti-HLA class I or II alloimmunization as well as retransplanta tion frequency between the patients who lost their graft and the patie nts who did not. Conclusion. Our results suggest that a pretransplant positive B-FCXM is associated with an impaired longterm graft survival in renal allotransplantation.