Protein A immunoadsorption combined with rituximab in highly sensitized kidney transplant recipients

The 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.

Seven 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.

All 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.

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