Protein A immunoadsorption combined with rituximab in renal transplant recipients positive for panel reactive antibody(Report of 7 cases)

Objective To investigate the safety and efficacy of combined use of protein A immunoadsorption and rituximab(RTX)in kidney transplant recipients positive for panel reactive antibody(PRA).Methods Five cases received second transplantation,and 2 cases had the history of multiple pregnancies.All the cases received living-related kidney transplantation and all grafts came from male donors.Recipients and donors had the same blood type,and complement dependent cytotoxic (CDC)was negative.HLA mismatch number was 2-5.Three out of 7 cases had high PRA of both class Ⅰ and 11,2 cases had high class Ⅰ,and the rest 2 had high class Ⅱ.Mean immunoglobulin IgG,IgA,and IgM levels were 13.4,1.78,and 1.47g/L respectively.All patients were pretreated with immunoabsorption for 2-10 times(mean 5 times).Immunoglobulin and PRA changes were monitored before and after absorption.Transplantation was done after PRA or immunoglobulin levels were reduced to normal or below normal values.Before the transplantations single dose of RTX(375 mg/m2)was infused together with polyclonal antibody induction.All patients received immunosuppressive agents such as tacrolimus or cyclosporin A,mycophenolate mofetil and prednisone after transplantation.Creatinine(Cr),and creatinine clearance rate(Ccr)were monitored after transplantatioa Biopsy would be performed when rejection occurred.The percentage of peripheral blood B lymphocytes CD19 and CD20 was determined in 3 patients by using flow cytometry before transplantation and one week posttransplantation.Results There was no adverse reactions during the combined use of protein A immunoadsorption and RTX.The PRA of class Ⅰ and Ⅱ was descended after administration of protein A immunoadsorption.The average levels of IgG,IgA and IgM were also descended.Seven cases of kidney transplantation had a good recovery,with no delayed graft function (DGF).Three cases had acute rejection 8,10 and 14 days after transplantation respectively.Successful reversion was achieved after treatment.CD 19 before transplantation was 1.98 %,4.64 % and 4.45 % respectively,and 0.39 %,0.98 % and 0.11 % respectively after transplantation;CD 20 before transplantation was 15.15 %,2.01 % and 1.15% respectively,and 0.34 %,0.15 % and 0.01 % respectively after transplantatioa One patient developed a cytomegalovirus infection in lung,and successful reversion was achieved after treatment.One patient died of Aspergillus pneumonia with normal graft function.Conclusion The combined use of protein A immunoadsorption and RTX were effective to decrease the risk of the patients positive for PRA.After treatment,the patients could receive a successful kidney transplantation. Key words: Kidney transplantation; Panel reactive antibody; Immunosorbent techniques; Rituximab