Changes in maintenance immunosuppression after pediatric kidney transplantation: a report from the Nordic pediatric kidney transplantation registry

Background: Few studies are available on changes in maintenance immunosuppression after pediatric kidney transplantation (KT). This is a retrospective registry analysis of the long-term medication modifications in the Nordic countries. Methods: All pediatric KT recipients transplanted between the years 2005 and 2016 were identified from the Scandiatransplant registry. Of the 482 patients, 345 met the inclusion criteria: age below 16 years at KT and at least 2 years post-transplant follow-up. Results: A change in maintenance immunosuppression occurred in 160 patients (46.4%) at 2.0 (interquartile range 1.0–3.0) years median time from KT. The most common change (35.8%) was switching cyclosporine A (CsA) to tacrolimus (Tac). Initial CsA treatment was modified significantly more often compared to Tac (72.0% vs. 6.0%; p < 0.001). Modifications of mycophenolate mofetil (MMF) were observed more often in recipients aged < 2 (75.0%) and 2–5 (55.6%) years compared with 5–16 years (13.2%; p < 0.001); particularly, MMF discontinuation was common (< 2 years 45.8% and 2–5 years 38.9%). Otherwise, initial immunosuppression remained mainly unchanged. The main reasons for changing CsA to Tac were cosmetic side effects (26.2%), rejections (26.2%), and declining graft function (23.0%). In case of rejection or declining graft function, CsA-to-Tac conversion slowed the decrease in measured glomerular filtration rate. MMF modifications did not affect graft survival from 2 to 7.5 years post-transplant. Conclusions: Maintenance immunosuppression is modified in almost half of pediatric KT recipients. Particularly, CsA conversion to Tac and young recipients’ MMF modifications are common.