Sequential blood level monitoring of basiliximab during multisession plasmapheresis in a kidney transplant recipient

Basiliximab, a chimeric monoclonal antibody against the alpha chain of the interleukin-2 receptor (IL-2R) has been used in renal transplant patients. We monitored sequential blood concentrations of basiliximab in a patient who received a kidney transplant with basiliximab-based immunosuppression together with multiple sessions of plasmapheresis. A 34-year-old man received a living-related kidney transplant with induction immunosuppression including tacrolimus, mycophenolate, methylprednisolone, and basiliximab. Severe antibody-mediated acute rejection lead to a requirement for hemodialysis. Deoxyspergualin was administered for 10 days at a daily dose of 5 mg/kg combined with eight sessions of double filtration plasmapheresis (DFPP). After treatment, the serum creatinine returned to 0.95 mg/dL, and there were no major complications or infections. Sequential basiliximab blood levels of the patient were monitored following transplantation. The serum basiliximab concentration decreased by 72.4% after five consecutive DFPPs, and by 87.6% after eight DFPP sessions. The elimination rate of basiliximab (ΔBLX) was 6.1% before DFPP, but increased over eight DFPPs to 20.5%. Serum basiliximab concentrations declined to 0.16 μg/mL on day 33, which is below the IL-2R saturation concentration (0.2 μg/mL). Multiple sessions of plasmapheresis using DFPP enhanced the elimination of serum basiliximab at an average elimination rate of 19.1%. In the patient reported on here, the serum basiliximab concentration fell to below the IL-2R saturation level (0.2 μg/mL) within 1 month of living-related kidney transplantation. We recommend that additional basiliximab infusions be considered for cases undergoing more than three plasmapheresis sessions.