Clinical correlations of antibodies in pemphigus studied by radioimmunoassay.

Pemphigus antibodies of class G immunoglobulins (IgG) were studied with the use of a solid-phase radioimmunoassay (RIA) that utilizes COLO-16, a squamous cell tumor line, as the substrate. Sera from patients with pemphigus vulgaris and pemphigus vegetans showed greater average binding than did sera from patients with pemphigus foliaceus and pemphigus erythematosus. The patients were subgrouped according to their clinical presentations and were divided into patients with skin lesions only, those with mucous membrane lesions only, and those with both skin and mucous membrane lesions. No significant differences were observed between these groups. There was good correlation between IgG binding in the RIA and both the disease activity and the response to therapy. Blood group antigen absorbable "false positive" anti-intercellular substance antibodies were not detected in the RIA.