Mc. Bittencourt et al., IMPAIRED RENAL GRAFT-SURVIVAL AFTER A POSITIVE B-CELL FLOW-CYTOMETRY CROSS-MATCH, Nephrology, dialysis, transplantation, 13(8), 1998, pp. 2059-2064
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.