Immunodiagnosis of mesothelioma: use of antimesothelial cell serum in an indirect immunofluorescence assay.

Cells isolated from human serous effusions were cultured in vitro. Monolayers of large multipolar cells were established. Antisera to the cultured cells were prepared in rabbits and rats. The antisera were absorbed with human red cells, liver powder and MOLT-4F cell line lymphocytes. Specificity of the absorbed antisera for human mesothelial cells were demonstrated in an indirect immunofluorescence assay. The antisera were used to confirm the diagnosis of mesothelioma in two cases. In both the patients, the morphologically identifiable malignant cell populations in the effusions stained positively with the antimesothelial cell serum thus establishing their mesothelial origin. Normal nonmesothelial tissue and known nonmesothelial tumors failed to react with the antisera thus confirming the specificity of the antisera.