An enzyme immunoassay for auto-antibodies to keratin in normal human serum and in pleural fluids from patients with various malignant or non-malignant lung diseases.
An enzyme-linked immunosorbent assay (ELISA) for anti-keratin antibodies was prepared by coating microplates with epidermal keratin purified from the stratum corneum from human foot. Naturally occurring auto-antibodies bind keratin via their f(ab')2 fragment. They were assayed in the serum from 65 healthy people. The serum titer increased significantly with aging. Auto-antibodies stained all the layers of a normal human epidermis whereas an immune serum, prepared by injecting a rabbit with pure human keratin proteins, stained more efficiently the outer layers of the human skin; pre-immune rabbit serum did not stain human skin at all. The lowest anti-keratin activities were observed in serum from patients with squamous cell lung carcinoma and with mesothelioma. The activity was lower in pleural fluid from patients with pleural mesothelioma than in pleural fluid from other types of cancer. This is possibly due to the fixation of autoantibodies onto the pleural tumor or on cell debris arising from the tumor.
D000818:Animals; D000906:Antibodies / Q000276:immunology; D001323:Autoantibodies / Q000032:analysis* / Q000276:immunology; D002294:Carcinoma, Squamous Cell / Q000097:blood / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D006651:Histocytochemistry; D006801:Humans; D007124:Immunoenzyme Techniques; D007633:Keratins / Q000276:immunology*; D008171:Lung Diseases / Q000097:blood* / Q000276:immunology; D008175:Lung Neoplasms / Q000097:blood* / Q000276:immunology; D008654:Mesothelioma / Q000097:blood / Q000276:immunology; D010996:Pleural Effusion / Q000276:immunology*; D011817:Rabbits / Q000276:immunology
D000906:Antibodies; D001323:Autoantibodies; D007633:Keratins