bronchiolitis obliterans following hematopoietic stem cell transplantation: risk factors and diagnostic methods

introduction: bronchiolitis obliterans (bo) is one of the most important pulmonary complications of hematopoietic stem cell transplantation (hsct). we decided to evaluate the prevalence and risk factors of bo in hsct patients in the shariati hospital oncology research center. materials and methods: forty two patients, who had had hsct for at least 6 months ago, completed the study. the diagnosis of bo was confirmed either by spirometry or inspiratory and expiratory views of hrct with a fev 1 /fvc lower than 75% or more than a 10% drop of fev 1 /fvc from a baseline value and mosaic or air trapping on hrct, respectively. results: nineteen out of forty two patients were bo, with a prevalence of 45.2%; seventeen cases by hrct and eleven by spirometry criteria. identified risk factors for bo were acute and chronic gvhd, age 21-40 yrs. female donor to male recipient and unmatched genders. there was a strong negative predictve value of symptoms under age 20. conclusion: young patients under 20, without respiratory symptoms, need no further evaluation. acute and chronic gvhd are again the main risk factors regarding female donors to male recipients within the age group of 21-40.