Impact of late conversion from C0 to C2 monitoring of microemulsified cyclosporine in pediatric living donor liver transplant recipients

The efficacy and feasibility of 2-h post-dose level (C2) monitoring of cyclosporine in long-term living donor liver transplantation (LDLT) is not clear. The aim of this study was to investigate the impact of late conversion from conventional trough-level (C0) monitoring to C2 monitoring of a microemulsion form of cyclosporine (Neoral) in pediatric LDLT recipients. From June 1994 to August 2002, we performed 116 LDLTs in 115 patients. Initially, we adapted conventional C0 monitoring of Neoral, which was converted to C2 monitoring starting in January 2002. The 60 patients who were enrolled in the study had the following characteristics: they were younger than or equal to 15 yr at transplantation, and they had survived LDLT, and they had received a Neoral-based immunosuppression regimen, and they underwent conversion to C2 more than 1 month after transplantation. We evaluated the impact of conversion on doses, blood levels, rejection, adverse effects, and patient/graft outcome. In the long-term patients, the mean C2 levels immediately after conversion were higher than the target levels at any time point selected after transplantation; thus, 34 patients (57%) finally required a dose reduction of Neoral. The current mean C2 level was significantly lower than that observed immediately after conversion (584.6 ± 262.8 ng/ml vs. 893.1 ± 260.2 ng/ml, mean ± SD, p < 0.0001) with a mean follow-up period of 7.4 ± 0.6 months (range: 5-8 months) after conversion. Only one patient encountered rejection after conversion (1.7%), and no de novo infection or adverse effects were observed. Traditional C0 monitoring of Neoral was safely replaced by C2 monitoring without an increase in the rejection rate or any adverse effects in pediatric LDLT patients. C2 monitoring contributed to the dose reduction of Neoral, which may lead to the avoidance of long-term complications due to immunosuppression.