Conversion to C2 monitoring of cyclosporine A exposure in maintenance kidney transplant recipients:: Results at 3 years

Background It has been suggested that conversion from monitoring cyclosporine A (CsA) trough level to the level 2 hours after the morning dose (CO may have clinical benefits in maintenance adult renal transplant recipients, but evidence supporting such a suggestion presently is very limited. Methods: We enrolled 188 maintenance patients to investigate the clinical impact of the adjustment of CsA dose according to C-2 levels over 3 years (target, 800 ng/mL). Results: Patient and graft survival rates were 100% and 98.4%, respectively. C-2 monitoring led to a reduction in CsA dose in 49.4% of patients and an increase in more than 20% of patients without an increase in acute rejection risk and clinically overt nephrotoxicity. Patients in the greatest quartile of C-2 levels showed the lowest serum creatinine levels (P = 0.009), the greatest creatinine clearance values (P = 0.0006), and the lowest prevalence of chronic allograft nephropathy (P = 0.01). By means of multivariate analysis, C-2 levels were the most relevant independent predictors of graft deterioration (change in serum creatinine level from baseline to end of study greater than or equal to0.5 mg/dL [greater than or equal to44 mumol/L]). Receiver operating characteristic analysis showed an inflection point of mean C-2 level versus risk for graft deterioration at less than 661 ng/mL. Conclusion: In maintenance renal transplant recipients, conversion to C-2 monitoring is a seemingly safe option with good graft performance after 3 years. Mean C-2 levels greater than 661 ng/mL seem to be associated with better long-term graft function and a lower prevalence of biopsy-proven chronic allograft nephropathy, at least during a 3-year follow-up.