Pulmonary complications are common and often lethal in hematopoietic SCT recipients. The objective of this prospective interventional study was to evaluate the etiology, diagnostic procedures, risk factors and outcome of pulmonary complications in a cohort of hematopoietic SCT recipients followed up for 1 year. For patients suffering from a pulmonary complication, a diagnostic algorithm that included non-invasive and bronchoscopic procedures was performed. We identified 73 pulmonary complications in 169 patients: 50 (68%) were pneumonias; 21 (29%) were non-infectious complications and 2 (3%) were undiagnosed. Viruses (particularly Rhinovirus) and bacteria (particularly P. aeruginosa) (28 and 26%, respectively) were the most common causes of pneumonia. A specific diagnosis was obtained in 83% of the cases. A non-invasive test gave a specific diagnosis in 59% of the episodes. The diagnostic yield of bronchoscopy was 67 and 78% in pulmonary infections. Early bronchoscopy (⩽5 days) had higher diagnostic yield than late bronchoscopy (78 vs 23%; P = 0.02) for pulmonary infections. Overall mortality was 22 and 32% of all fatalities were due to pulmonary complications. Pulmonary complications are common and constitute an independent risk factor for mortality, stressing the importance of an appropriate clinical management. The increasing number of indications and the selection of more debilitated patients as potential candidates for HSCT seem to be changing the epidemiology of PC. 5,6 Studies have shown that in immunocompromised patients an early identification of the etiology of PC improves survival. 7,8 Fiberoptic bronchoscopy (FOB) has an important role in the diagnosis of PC; 9-12 however, detractors of this technique consider that the information provided may be also obtained by different non-invasive explorations. [13][14][15] The majority of the studies evaluating the etiology, diagnosis and prognosis of PC in patients with hematologic diseases are retrospective, 4,6,16 and include both non-transplantation and transplantation recipients. 2,7 We hypothesized that the prospective follow-up of a cohort of HSCT recipients may improve the clinical management of PC. First, the knowledge of the epidemiology of the PC with the different prevalence of infectious and non-infectious etiologies can be accurately determined. Second, predetermined criteria for performing a FOB should clarify the role of this technique by better defining the diagnostic yield, clinical implications and potential complications. Finally, the identification of prognostic factors is much more precise when data are recorded prospectively in a homogeneous group of immunocompromised patients.The aim of this study was to evaluate the incidence, diagnostic and clinical implications of non-invasive and FOB explorations, risk factors and outcome of PC. To this aim, a cohort of consecutive patients requiring HSCT was followed-up for 1 year and the PC were closely analyzed.

Prior treatment with ICS in a population of patients with different respiratory chronic disorders who develop pneumonia is associated with lower incidence of parapneumonic effusion.