Cyclosporin A monitoring by 2-h levels: preliminary target levels in stable pediatric kidney transplant recipients.

Clinical trials in adults have shown that management of transplanted patients with cyclosporin A (CsA) 2-h levels (C2) lead to superior outcome compared with monitoring of 12-h trough levels (C0). In both adults and children, C2 levels enabled a better estimation of the area under the curve concentration than C0 levels. Therefore, it can be suspected that C2 monitoring might also lead to a better outcome in children. Until now C2 target levels for children have not been defined. We measured C2 levels in 101 stable pediatric kidney recipients with a minimum time of 1 yr after transplantation. C2 levels were compared with changes in glomerular filtration rate (GFR) 6 months later. Median C2 levels in children after renal transplantation were 714 ng/mL (95% confidence interval 654-774). Patients with C2 levels below 750 ng/mL had a significantly higher percentage of decline in GFR than patients with C2 levels above 750 ng/mL (p < 0.05). In children with C2 levels below 500 ng/mL three acute rejections occurred in comparison with no rejection in the remaining patients (p < 0.05). We conclude that the lower C2 target level should be above 750 ng/mL in stable pediatric transplant recipients. An upper target level above 1000 ng/mL should be avoided. The question, whether C2 monitoring in pediatric kidney recipients is superior to C0 monitoring, is yet to be answered.