Airflow obstruction in sarcoidosis

. Aberrations in pulmonary function test are present in about 20% of patients with radiographic stage I sarcoidosis, whereas the pulmonary function is damaged in 40-80% of patients with parenchymal infiltrates (stages II, III or IV). Discussion and Review of Literature. Reductions in lung volumes (vital capacity and total lung capacity) are characteristic. The diffusing capacity of lungs is often reduced, but it is less pronounced in sarcoidosis than in idiopathic pulmonary fibrosis. Oxygenation is usually preserved until late in the course of sarcoidosis. Airflow obstruction (reduced forced expiratory volume in one second and expiratory flow rates) and bronchial hyper-reactivity occur in 30-50% of sarcoidosis patients with pulmonary parenchymal involvement. Conclusion. While restrictive spirometry pattern could easily be explained by fibrous changes in lung parenchyma, especially in late stages of the lung disease, pathogenesis of airflow limitation can be attributed mostly to endobronchial involvement (intraluminal granuloma or fibrous scars formation), airway compression due to enlarged lymph nodes and to distortion of small airways due to established pulmonary fibrosis. [Projekat Ministarstva nauke Republike Srbije, br. 175046 i br.175081