BACKGROUNDThe number of highly sensitized patients is rising, and sensitization can lead to renal transplant failure. The present study aimed to investigate the safety and efficacy of protein A immunoadsorption combined with rituximab (RTX) in highly sensitized recipients of kidney transplants.

METHODSSeven highly sensitized recipients of living-related renal transplants (4 men and 3 women, mean aged 42.5 years old (range 33 - 51)) were pretreated with this combination. Human leukocyte antigen (HLA) mismatch number was 2 - 5. Panel reactive antibody (PRA) of class I was high in 2 cases and that of class II was high in 1 case. All patients were pretreated with immunoadsorption 2 - 10 times. Immunoglobulin and PRA changes were monitored before and after absorption. The operation was conducted when PRA or immunoglobulin levels were at or below normal levels. Immunosuppressive drugs were provided 3 - 5 days before the operation, and one dose of RTX (375 mg/m(2)) was infused with polyclonal antibody on the day of operation. Postoperative creatinine (Cr), creatinine clearance rate (Ccr), PRA ratio, and immunoglobulin changes were monitored.

RESULTSAll 7 patients had good recovery without delayed graft function. Acute rejection occurred in 3 cases at postoperative days 8, 10, and 14, respectively. The Banff 07 biopsy grades were Ia in 1 case and IIa C4d0 in 2 cases. Successful reversion was achieved after giving methylprednisolone or antithymocyte immunoglobulin + cyclophosphamide. All patients were discharged with normal renal function, mean class I PRA was 14% and mean class II PRA was 35%. PRA was completely negative in 3 cases.

CONCLUSIONProtein A immunoadsorption combined with RTX can safely reduce the occurrence of humoral rejection in highly sensitized renal transplant recipients.