IDENTIFICATION OF HIGH-RISK AND LOW-RISK 2ND KIDNEY GRAFTS

The purpose of this study was to identify recipients who are at low or high risk of early cadaveric regraft failure by segregating results o f the flow cytometric crossmatch (FCXM) test with previous graft survi val time (PGST). Early immunologic kidney regraft failure was analyzed in 103 multicenter recipients by cross-stratifying FCXM negative/posi tive status with less than or equal to 3- and >3-month PGST. T cell an d B cell cytotoxicity crossmatches were negative, All were tested retr ospectively in the T cell FCXM and 60 of the 103 were also tested in t he B cell FCXM. A positive T and B cell FCXM was defined as a mean cha nnel shift of greater than or equal to 9 (256 channel log scale) or gr eater than or equal to 40 (1024 channel log scale) for pretransplant c rossmatch serum above negative control serum, Recipients received trip le immunosuppression therapy and limited-use antilymphocyte induction therapy. Early cadaveric regraft losses were biopsied, Comparably good rates of second kidney graft survival at 3 years were found among thr ee low risk subsets: 78% for 18 FCXM-positive patients with PGST >3 mo nths, 78% for 49 FCXM-negative patients with PGST >3 months, and 84% f or 19 FCXM-negative patients with PGST less than or equal to 3 months, In contrast, 53% 3-month and 44% 3-year regraft survival rates occurr ed in 17 high-risk FCXM-positive recipients with a PG;ST less than or equal to 3 months, The odds ratio for increased relative risk of early second graft loss was 4.5 (confidence interval: 1.32-16.7) for the hi gh-risk Versus low-risk subsets (P=0.009), Within the high-risk subset , 56% (5 of 9) of those who were FCXM T negative B positive experience d early regraft loss. A positive B cell FCXM has an adverse clinical i mpact only for high-risk regraft recipients, Pretransplant panel react ive antibody levels, pregnancy, number of blood transfusions between g rafts, repeat donor HLA mismatches, and regraft-recipient HLA mismatch es did not correlate with early regraft loss, We conclude that kidney regraft survival rates in low-risk recipients (PGST >3 months/FCXM. ne gative or positive [T and/or B cell] and PG;ST less than or equal to 3 months/FCXM negative) approach primary graft survival rates and justi fy retransplantation, but the rate in high-risk regraft candidates (PG ST less than or equal to 3 months/FCXM positive T and/or B cell) sugge sts that retransplantation should be performed only with a negative FC XM.