In vitro synthesis of immunoglobulins, secretory component and complement in normal and pathological skin and the adjacent mucous membranes.

A study on the synthesis of immunoglobulins (IgG, IgA, IgM, IgD, and IgE), secretory component and complement in normal and pathological skin and in the adjacent mucous membranes (i.e. conjunctiva, nasal, oral and vaginal mucosa) is reported. The results are based on the culture of tissue samples in a medium with two radioactive amino acids and the detection of synthesized proteins by autoradiography of the immunoelectrophoretic pattern of the culture fluid, except in the case of IgE for which the Ouchterlony technique was used. The results indicate that the normal skin does not synthesize immunoglobulins, whereas normal mucous membranes produce IgG and IgA. In the lesions of various skin diseases immunoglobulins are synthesized, mainly IgG but sometimes also IgA and IgE. The cells responsible for the production of immunoglobulins are plasma cells and lymphoid cells present in the skin lesions and mucous membranes. Synthesis of the free secretory component could be demonstrated only in certain mucous membranes (i.e. conjunctiva, nasal mucosa, and oral mucosa). Complement (C3) synthesis was found in normal skin, mucous membranes (i.e. conjunctiva, nasal and oral mucosa), and in the lesions of such skin diseases as discoid lupus erythematosus, (bullous) pemphigoid, dermatitis herpetiformis, malignant reticulosis, eczema and lichen planus. Complement production was also demonstrated in allergic skin reactions (i.e. tissue from allergic-positive patch tests, positive Mantoux tests and drug eruptions), but no immunoglobulin synthesis was detected in these lesions.