Is It Possible to Predict Pulmonary Complications and Mortality in Hematopoietic Stem Cell Transplantation Recipients from Pre-Transplantation Exhaled Nitric Oxide Levels?

Chemo/radiotherapy-induced free oxygen radicals and reactive oxygen derivatives contribute to the development of early and late transplantation-related pulmonary and extra-pulmonary complications in hematopoietic stem cell transplantation (HSCT) recipients. It has been proposed that an increase in fractional exhaled nitric oxide (FeNO) level indicates oxidative stress and inflammation in the airways. The aim of this prospective study is to evaluate the pre-transplantation FeNO levels in HSCT patients and to search for its role in predicting post-transplantation pulmonary complications and mortality. HSCT patients were included in the study prospectively between October 2009 and July 2011. Pre-transplantation FeNO levels were measured with a NIOX MINO® device prior to conditioning regimens. All patients were monitored prospectively for post-transplantation pulmonary complications with medical history, physical examination, chest X-ray, and pulmonary function tests. A total of 56 patients (33 autologous, 23 allogeneic) with mean age of 45±13 years were included in the study, among whom 40 (71%) were male. Pre-transplantation FeNO level of the whole study group was found to be 24±13 (mean ± standard deviation) parts per billion (ppb). The FeNO level in allogeneic HSCT recipients was 19±6 ppb while it was 27±15 ppb in autologous HSCT recipients (p=0.042). No significant correlation was found between the pre-transplantation chemotherapy and radiotherapy protocols and baseline FeNO levels (p>0.05). Post-transplantation pulmonary toxicity was identified in 12 (21%) patients and no significant relationship was found between baseline FeNO levels and pulmonary toxicity. The survival rate of the whole study group for 1 year after transplantation was 70%. No significant relationship was identified between baseline FeNO values and survival (FeNO 19±7 ppb in patients who died and 26±15 ppb in the survivors; p=0.114). Pre-transplantation FeNO measurement does not seem to have a role in predicting post-transplantation pulmonary complications and mortality.