Immunogenetic findings in cutaneous lupus erythematosus.

The serologic features and histocompatibility antigen associations of 93 patients with cutaneous lupus erythematosus are reported. Of them, 37 had chronic cutaneous lupus erythematosus and 56 had subacute cutaneous lupus erythematosus. Subacute cutaneous lupus erythematosus with an annular pattern occurred in 32 patients; 24 had a papulosquamous morphology. Sixty percent of patients with annular subacute cutaneous lupus erythematosus had anti-Ro antibodies. The incidence of this antibody in the other two groups was lower. In addition, patients with annular skin lesions had significant antigen association with HLA-B8 (37.5%; relative risk, 4.6) and HLA-DR3 (59.4%; relative risk, 4.3). There were no significant differences among chronic cutaneous lupus erythematosus and subacute cutaneous lupus erythematosus of the papulosquamous type and the control population for any HLA loci. Thus only patients with annular skin lesions represent a homogeneous subgroup in which there is a striking concordance of anti-Ro antibodies and the HLA-B8 and HLA-DR3 phenotypes.