Cyclosporine Effects on Pediatric Kidney Recipients

(1), entitled “Cyclosporine trough and 2 hour post dose monitoring and its contributing factors among pediat-ric kidney recipients,” recently published in the Nephro-Urology Monthly. The authors correctly mentioned that there is a negative relationship between cyclosporine A levels (C0 and C2) and serum creatinine. Based on their data, the mean of C0 levels (118 ± 65 ng/mL) was in the therapeutic range, which is an acceptable level of cyclo-sporine after 6 months using the EMIT (Enzyme multi-plied immunoassay technique) assay method (2). Then lower serum creatinine levels that better reflects graft function are predictable. Although in this study, the mean of C2 levels (471 ± 148 ng/mL) was lower than thera-peutic levels (600-800 ng/mL), patients had good graft function. This result can be explained by previous simi-lar studies in Iran in which most patients at therapeutic C2 levels presented with cyclosporine nephrotoxicity or the recipients did not reach target levels, so they didn’t recommend routine checking of C2 levels (2, 3). This may be due to genetic differences in drug metabolism in dif-ferent races which can lead to different peak levels or dif-ferent peak times (for example 3 or 4 hours after taking) in Iranian patients.Another factor that may impact on graft function con-sists of the donor’s demographic data such as type (ca-daveric