Monitoring of circulating antibodies in a renal transplantation population: preliminary results

The presence of circulating antibodies (CA) against human leukocyte antigen (HLA) and major-histocompatibility-complex class I-related chain A (MICA) antigens has been associated with worse renal function and reduced kidney allograft survival. We sought to describe the presence of donor-specific anti-HLA antibodies, non-donor specific antibodies, and antibodies against MICA antigens among a cohort of renal transplant recipients with respect to their evolution effects on renal function and occurrence of an acute rejection episode (AR) after transplantation.

This prospective study of 22 renal transplant recipients of deceased donor kidneys underwent studies of antibodies before and 3 months after grafting using Luminex technology.

Ten patients (five men and five women) showed preexistent CA. Comparing patients with versus without preformed CA, we did not observe a significant difference in donor and recipient age or gender. Eight patients (80%) with CA had undergone induction treatment with anti-human-activated T-lymphocyte rabbit immunoglobulin and 2 (20%) with basiliximab. There were no differences between groups regarding the incidence of acute rejection episodes (ARE n = 3 each). There was one case of Banff grade IIB ARE in a patient without preexisting CA; the other episodes were low-grade cellular responses. There were no differences in other variables including cold ischemia time, HLA mismatches, panel-reactive antibody levels, number of transfusions, cytomegalovirus infection or renal function at discharge and 3 months later. Retransplantation was the only factor associated with preformed CA. Retransplantation and preformed CA were associated with CA at 3 months after transplantation.

CA monitoring is important for highly sensitized renal transplants, although our experience failed to show a difference in graft survival or renal function in the first 3 months' follow-up.