IS A POSITIVE B-CELL CROSSMATCH ALWAYS BAD?

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IS A POSITIVE B-CELL CROSSMATCH ALWAYS BAD?
Prakash Rao Ph.D , Stephen B. Skelton, B.S. , Rodney L. Crenshaw, B.S. , Mario Magnone M.D. , Velma Scantleburry M.D. and Leroy Thacker Ph.D . Mobile Al, USA, University of South Alabama Medical Center, 36617, Department of Pathology & Surgery and Richmond VA, USA, South Eastern Organ Procuremnt Foundation, 23235, SEOPF .

In renal transplantation, the role of a positive B cell crossmatch on graft survival remains controversial. In this study, we retrospectively analyzed data from the SouthEastern Organ Procurement Foundation (SEOPF) on 13,968 transplants performed between 10-1-87 and 12-31-96. Inclusion criteria were transplants where B & T cell crossmatches were performed, and on whom survival data was available. The 13,968 transplants were divided into 4 groups; l) those with negative B & T cell crossmatches, 2)B cell positive, T cell negative; 3)B cell negative, T cell positive; 4)B cell positive, T cell positive. Chi-square analysis testing the assumption of independence showed a highly significant difference (p<.0001), with the greatest contribution being in the B cell positive/T cell positive group. Graft failure was defined as a return to dialysis following transplant. Graft and patient survival for the four groups were computed using Kaplan-Meirer estimates and tests of equality of survival curves were done utilizing both the Log Rank and Wilcoxon tests. A significant difference in survival is observed between the four groups by both the Log Rank (χ²= 17.9215, p. = .0005) and Wilcoxon (χ²= 36.9833, p=.000l) tests. However, survival in the B cell negative/ T cell positive group is significantly worse than the B cell negative/T cell negative group(χ² =15.1920, p. = .000l), and the B cell positive/T cell negative group(χ²11.2285, p. = .0008). Our results suggest that there is: no effect of a positive B cell crossmatch if the T cell crossmatch is negative, strong effect of a positive B cell crossmatch if the T cell crossmatch is positive. Conclusion: Must take B cell crossmatch into consideration if one decides to do a transplant across a positive T cell crossmatch.