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

Background 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.Methods 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 Ⅰwas high in 2 cases and that of class Ⅱwas 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.Results 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 la in 1 case and lla 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 ⅡPRA was 35%. PRA was completely negative in 3 cases. Conclusion Protein A immunoadsorption combined with RTX can safely reduce the occurrence of humoral rejection in highly sensitized renal transplant recipients.

Protein A immunoadsorption therapy in the highly sensitized kidney transplant candidates

Background Sensitization in transplant candidates increases risk of irreversible immunologic injury of graft in the early period postoperatively. Elimination of anti-human leukocyte antigen （HLA） antibodies using protein A immunoadsorption （IA） might benefit these patients.Methods Protein A IA was used in 21 patients with high panel reactive antibody （PRA）. The patients had IA 1-6 times （median 5 times） with the interval period was 2-5 days （median 2.5 days）.Results Total 67 IA procedures were carried out smoothly in all patients. IA treatment reduced PRA I （pre （31.4±3.8）% vs. post （24.4±3.4）%, P 〈0.01） and II （pre （37.1±4.3）% vs. post （34.1±3.9）%, P 〈0.01）. However, PRA did not change in some patients after the treatment. The serum immunoglobulin （IgG, IgM and IgA） and complement C3, C4 level were decreased significantly. Hemoglobin and albumin levels were slightly decreased associated with IA procedures. Flu-like symptoms were observed in a few of cases during the procedure but generally mild and transient.Conclusion Protein A IA is capable to efficiently remove serum immunoglobulin and complement, reduce HLA class I and class II PRA in high sensitized transplant candidates, which is likely to benefit the kidney transplantation in these patients.