Background
HYPERSENSITIVITY PNEUMONITIS, PULMONARY FIBROSIS, HYPERSENSITIVITY PNEUMONITIS, DISEASES, DISORDERS, COMPLICATION, PULMONARY HYPERTENSION, ALYMPHOCYTOSIS, PULMONARY HYPERTENSION
Hypersensitivity pneumonitis (HP) is a complex immune mediated disorders caused by repeated inhalation of and sensitization to wide range of antigens including organic particles and chemical compounds, leading to exaggerated immuneresponse [HP is classified into two subtypes according to computed tomography findings into fibrotic and non-fibrotic HP. Diagnosis of HP is challenging especially the fibrotic subtype. A multidisciplinary approach including exposure history, HRCT findings, BAL lymphocytosis over 50% and lung tissue biopsy can be used to determine the likelihood of hypersensitivity pneumonitis [The inflammatory process in HP affect small airways and lung parenchyma with development of pulmonary fibrosis, which lead to impairment of exercise capacity and pulmonary hypertension (PH) [Pulmonary hypertension has been found as a complication of a number of diseases affecting the lung interstitium, including hypersensitivity pneumonitis, with subsequent affection of the mortality [