Epidermal nuclear immunoglobulin deposits in some connective tissue diseases: correlation with ENA antibodies

In-vivo nuclear deposits of IgG were demonstrated by direct immunofluorescence in epidermal cells of normal skin from 6 patients with serum antibodies to an RNase-sensitive extractable nuclear antigen (ENA). Addition of complement to the skin sections showed that C3 could bind to epidermal cells with IgG deposits. A skin biopsy from a patient with polymyositis and serum antibodies to ENA, but without nuclear IgG deposits, showed nuclear binding of C3 after addition of complement to the skin sections. The clinical diagnoses of patients with immunofluorescent staining of epidermal cells were mixed connective tissue disease (MCTD) 4 cases, systemic lupus erythematosus (SLE) 2 cases, and polymyositis 1 case. No epidermal nuclear IgG deposits could be demonstrated in 5 cases of SLE, 2 cases of MCTD, one case of polymyositis, or 15 cases of rheumatoid arthritis without antibodies to ENA.