Detection of psoriasis-associated antigen pso p27 in sarcoidosis bronchoalveolar lavage fluid using monoclonal antibodies.

Sarcoidosis is a multisystem granulomatous disorder of unknown etiology, predominantly affecting the lung. The increased concentration of pulmonary lymphocytes with specific receptors in subgroups of sarcoidosis patients suggests a local specific immune response. pso p27, a psoriatic scale antigen linked to the pathogenesis of psoriasis, was previously found in BAL cells, serum, and Kveim-Siltzback test in sarcoidosis. With an enzyme-linked immunoassay based on murine monoclonal antibodies, we analyzed BAL fluid from 21 patients with pulmonary sarcoidosis. Eleven (52%) of the patients have detectable levels of pso p27 antigen. No antigen is detected in the BAL fluid from five healthy, nonsmoking controls. Serum concentrations of pso p27 shows no significant difference between the two groups, but three of the sarcoidosis patients have detectable levels of the antigen. Mean concentration of pso p27 is >100 fold higher in BAL fluid than in serum from the sarcoidosis patients. This strongly suggests local pulmonary production of pso p27 antigen.