Is positive flow cytometric cross-match a risk factor for early cadaveric kidney graft dysfunction?

The final decision about transplantation is based primarily on a negative result of a complement-dependent cytotoxicity cross-match. The significance of a positive flow cytometric cross-match (FCXM) is unclear.

From July 2002 to October 2004, FCXM was performed prior to cadaveric kidney transplantation in 63 patients aged 1.5 to 26 years (mean 13 +/- 5). Immunosuppression (not adjusted to results of FCXM) was considered standard (prednisone + mycophenolate mofetil or azathioprine + cyclosporine or rapamycin) in 57%, or "enhanced" (+ monoclonal antibodies and/or tacrolimus) in 43% of patients.

Immunoglobulin IgG and/or IgM antibodies against T and/or B cells were found in 14/63 patients (22.2%). The distribution of immunosuppressive regimens was similar for FCXM(+) and FCXM(-) patients. Deteriorated graft function (creatinine > or =1.5 mg/dL) or demand for dialysis was observed in 6/14 (42.9%) FCXM(+) group versus 6/49 (12.2%) in the FCXM(-) group. During the first month after kidney transplantation biopsy-proven rejection episodes occurred more frequently among the FCXM(+) than the FCXM(-) group: 21.4% versus 4.1%, respectively. During the first 3 months after transplantation two of four kidneys in the FCXM(+) group (14.3%) demonstrated histological evidence of rejection plus one case of immunological cause of graft failure later found to be associated with an extremely high panel-reactive antibodies that were absent before transplantation (altogether 21.4%). Only one kidney (2.0%) was lost due to rejection among the FCXM(-) group.

A positive flow cytometric cross-match should be considered an important risk factor for early kidney graft dysfunction.