Clinical features of late onset non-infectious pulmonary complications following pediatric allogeneic hematopoietic stem cell transplantation

Background: Late onset non-infectious pulmonary complications (LONIPCs) are major causes of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (allo-HSCT). We evaluated the incidence and the outcomes of LONIPCs in children who underwent allo-HSCT. Methods: Data for 143 children who underwent allo-HSCT at Asan Medical Center between April 2002 and April 2009 were reviewed, and the 127 who survived more than three months were enrolled. Results: Eleven (8.7%) developed LONIPCs at a median eight months (range 3-14 months) after allo-HSCT, presenting with cough and dyspnea. Six had bronchiolitis obliterans and five had idiopathic pneumonia syndrome. FVC declined more significantly in LONIPC than in non-LONIPC patients three months after HSCT. A significant risk factor for the development of LONIPCs was chronic graft-versus-host disease (GVHD) (p = 0.002). At a median follow-up of 36 months, the three-yr overall survival rate in LONIPC patients was significantly lower than that of non-LONIPC patients (37.4% vs. 72.7%, p = 0.02). The major cause of death was respiratory failure. Conclusions: Along with chronic GVHD, deterioration of pulmonary function at three months after HSCT may help in the early identification of patients at risk of subsequent LONIPCs. Considering the poor prognosis of LONIPC, strategies should be aimed at their prevention.