Monotherapy Immunosuppression in Pediatric Heart Transplant Recipients.

Although dual-drug immunosuppression is standard for rejection prophylaxis in pediatric heart transplant (HT), single-drug immunosuppression (monotherapy) may be sufficient for certain patients. We describe the experience with monotherapy at a single institution. Retrospective review of HT patients at a single pediatric transplant center who underwent HT between from 1/2001- 12/2020 and were treated with calcineurin-inhibitor monotherapy for > 1 month. Patients were transitioned to monotherapy per primary clinician due to concerns for over-immune suppression or post-transplant lymphoproliferative disorder (PTLD). Clinical characteristics and patient outcomes were analyzed. During the study period, 12/333 (3.6%) patients were placed on monotherapy at a median of 4.6 years post-HT [IQR 1.9-6.7 years]. Ten (83%) were transplanted as infants and 6 (50%) were transplanted for congenital heart disease. Nine (75%) were on tacrolimus monotherapy and 3 were on cyclosporine monotherapy. Indication for monotherapy was serious or chronic infection in 6 (50%), PTLD in 4 (33%), and neutropenia in 2 (16%). At a median follow-up of 1.5 years [IQR 1.1-2.2 years], 2 (16%) patients experienced grade 1B/1R cellular rejection, one of which required mechanical support and was transitioned back to dual therapy immunosuppression. All patients remain alive, with the remaining 11 (91%) still on monotherapy at time of last follow-up. Monotherapy immunosuppression with calcineurin inhibitors can be safely used in a subset of pediatric HT patients with evidence of over-immune suppression without significant increase in rejection. [ABSTRACT FROM AUTHOR]