Mycophenolate mofetil in pediatric heart transplant recipients: A single-center experience

Mycophenolate mofetil(MMF) is emerging as an effective agent for the treatm ent of both established rejection and primary rejection prophylaxis in soli d-organ transplantation (Tx), However, little data is available on the use of MMF in the pediatric population, We therefore report on our experience w ith MMF in 21 pediatric heart transplant recipients, Data were obtained by retrospective chart review. Median age at time of review was 12.3 yr (range 11 months to 16.9 yr). Median age at Tx was 10.7 yr (range 55 days to 16.7 yr), MMF was started at a median of 4.3 months after Tx (range 1 day to 4. 5 yr). Ar the time of MMF institution, all patients were concurrently on pr ednisone and azathioprine: 20 of these patients were also undergoing treatm ent with tacrolimus (median dose 0.18 mg/kg, range 0.03-0.64 mg/kg) and one with cyclo-sporin A (10 mg/kg), Azathioprine was discontinued at the time of commencing MMF. The average MMF dose was 40 +/- 14 mg/kg. The rationale for switching to MMF included rejection (International Society for Heart an d Lung Transplantation [ISHLT] 3A/B), 66%; inability to wean steroids, 14%; ABO blood group donor-recipient mismatch, 10%: coronary artery disease (CA D), 5%; and side-effects of immunosuppression, 5%. Of the patients switched for rejection, 93% demonstrated resolved or improving I ejection. Both ABO donor-recipient mismatch patients were started on tacrolimus/MMF as primar y therapy and had Ilo significant episodes of rejection. Two patients had r ejection classified as unchanged tone with CAD, one treated with addition o f sirolimus prior to improvement). Corticosteroids were successfully discon tinued in 28% of patients, and 20% are currently on a reduced dose. Fourtee n pet cent developed significant rejection while attempting to reduce the s teroid dose. Steroid reduction has not yet been attempted in 38%, of patien ts. The following side-effects were reported in 38% of the patients: diarrh ea, 10%; gastrointestinal discomfort, 20%; and leukopenia, 20%. Dose reduct ion or temporary discontinuation was required in 63% of the patients who ex perienced side-effects (24% of the total number of patients), Opportunistic infections developed in 10% (cryptococcus, cytomegalovirus). Hence, MMF ap pears to be effective for treatment of rejection in the pediatric heart tra nsplant population and has an acceptable side-effect profile. In addition, it may have a role in primary rejection prophylaxis and may facilitate a re duced steroid dosage or a steroid-free immunosuppression regimen.