Immunochemical Analysis of Bronchogenic Carcinomatous Sputum with Special Reference to Secretion-Specific Protein

¹ Evelyn Castera Cancer Research Laboratory, Department of Infectious Diseases, School of Medicine, University of California, Los Angeles, and Pulmonary Disease Service, Veterans Administration Hospital, Long Beach, California

Antigenic components of sputa from patients with bronchogenic carcinoma and from other patients with non-neoplastic pulmonic diseases were analyzed by double gel diffusion and by immunoelectrophoresis. Ninety-five per cent of the specimens gave positive precipitin reactions with both rabbit antiserum against pooled bronchogenic carcinomatous secretions and rabbit antiserum against pooled non-carcinomatous secretions. No statistically significant difference was observed between the two types of sputa. Immunoelectrophoretic patterns of the sputa when reacted with anti-secretion sera were similar to but not indentical with serum patterns. The former showed more complex precipitin arcs especially in the regions of ₂- and -globulins. A modified immunoelectrophoretic method demonstrated precipitin arcs with "reactions of identity" to those of _2a-globulin and to x-protein in serum. The method also demonstrated the presence of at least one precipitin arc having no "reaction of identity" with any of the arcs in human serum. Attempts to isolate and characterize the sputum-specific antigenic components are in progress. Significance of these findings are discussed.