Cyclosporine Therapeutic Monitoring With CMAX in Kidney Transplant Recipients: Impact of Schistosomal Infection

BACKGROUND The aim of the study was to assess whether the C2 level is a good parameter to predict a drug's maximal concentration (CMAX) values in Egyptian kidney transplant recipients (KTR). METHODS A total of 50 stable KTRs with a previously confirmed diagnosis of schistosomal infection compared to KTRs (n = 50) without schistosomal infection regarding cyclosporine (CsA) concentrations at time 0 (trough), 1.5, 2, 2.5, 3, and 3.5 hours post-CsA. The statistical significance of linear regression between different CsA time concentrations and drug dosages was calculated. RESULTS Patients in the schistosomal group had significantly lower C2 levels (511 ± 118 ng/mL) compared with the control group (669 ± 213 ng/mL; p < 0.05), whereas the C2.5 level was significantly higher (730 ± 215 and 527 ± 129 ng/mL, respectively; p < 0.05). Only C2.5 in the schistosomal group had a significant linear regression relationship with both morning CsA dose and CsA dose expressed as mg/kg/d (p = 0.0123, r = 0.573018). CONCLUSIONS Egyptian patients have special characteristics in drug absorption and metabolism, mostly due to schistosomal infection, and they may need the use of C2.5 for monitoring of CsA. If confirmed by subsequently larger studies, these findings may have a significant impact on our management of CsA immunosuppression in clinical renal transplantation in certain ethnicities.