Exhaled nitric oxide and pulmonary complications after paediatric stem cell transplantation

Pulmonary complications are major causes of morbidity and mortality after haematopoietic stem cell transplantation (HSCT). We hypothesise that elevated exhaled nitric oxide (FeNO) levels early after HSCT in children are predictive for pulmonary complications. The present prospective study included 30 children (age, 4–18 years) before HSCT. FeNO levels were evaluated 10 days before transplant, at day 0, day +28 and day +60 after HSCT. During the follow-up period until day +100, pulmonary complications and lung function were assessed. Before HSCT, the mean FeNO levels were comparable in children with or without post-transplant pulmonary complications. However, they differed at day 0 and day +28 with a mean of 7 (±1.95) and 13 (±3.44) ppb at day 0 and a mean of 13 (±3.44) and 14 (±3.57) ppb at day +28, respectively. Conclusion: Children with pulmonary complications after day +28 have higher mean FeNO levels 28 days after HSCT than children without later pulmonary complications. Therefore, FeNO could be an important diagnostic tool for hyperinflammatory response in bronchial epithelium after paediatric HSCT.