Acute rejection after paediatric heart transplantation: far less common and less severe.

Despite improved immunosuppression, rejection accounts for significant morbidity and mortality in children after heart transplantation. We report the incidence and outcome of rejection of 105 children (male = 50; mean age of 8.3 +/- 5.8 years) following heart transplantation between January 2002 and August 2007. A multi-variant model was constructed for risk factors associated with significant rejection. In 271.9 patient-years of follow-up, there were 23 episodes of significant rejection (>or=3A) in 21 patients (20%). Five presented in haemodynamic collapse requiring extracorporeal membrane oxygenation support 1.6-35.9 months after transplantation; four of five survived the rejection episode. Overall rejection episodes were more common in older children, boys and those treated with sirolimus. Whereas the risk for rejection in patients on an immunosuppression regime containing tacrolimus was significantly lower. The latter finding persisted on multivariate analysis (P < 0.002). Interestingly, none of the patients who presented with haemodynamic collapse was on mycophenolate mofetil. While our experience is of a far lower incidence of rejection than registry data, rejection remains a serious problem after paediatric heart transplantation. Sirolimus without a calcineurin inhibitor was associated with more rejection episodes, whereas tacrolimus and mycophenolate appeared to provide the best protective profile.