Value of enumerating cellular constituents of bronchoalveolar lavage fluid in differentiating sarcoidosis and cryptogenic fibrosing alveolitis.

Based on the observations of cellular constituents in the BAL fluid in 73 patients with sarcoidosis and 18 patients with cryptogenic fibrosing alveolitis, various diagnostic criteria for differentiating these two disorders were examined. Receiver operator characteristics curve was constructed using different levels of lymphocyte percent (L) in the BAL fluid. Discriminant accuracy was improved if the percent of polymorphs (P) was also taken into account. A log transformation of the ratio L/P + 1 was normally distributed and most useful in differentiating sarcoidosis from cryptogenic fibrosing alveolitis. A formal analysis of results may be helpful in assigning likelihood ratios for the observations on cellular constituents of BAL in patients suspected to have sarcoidosis.