2.2 Data collection
We collected data on demographics(sex, age, weight), symptoms/signs, hospital stay, blood investigations(whole blood count, neutrophil/lymphocyte/monocyte percentage, C reactive protein, procalcitonin, arterial blood gas, peripheral lymphocyte subset percentage), radiological imagings, bronchoalveolar lavage fluid analysis(lymphocyte subset percentage and neutrophil/lymphocyte/macrophage percentage), source of inhaled oil substance, comorbidity, number of therapeutic bronchoalveolar lavage and clinical course. Clinical course was classed into four categories as follows: complete or partial resolution; no chage; progression; lost to follow-up. Bronchoscopic data on lymphocyte subset was determined by flow cytometry.