Immunopathology of oral mucosa in bullous pemphigoid.

The immunopathology of the oral mucosa was studied in twenty-nine patients with bullous pemphigoid. The 14 patients with simultaneous involvement of the skin and oral mucosa had positive oral mucosa biopsies by direct immunofluorescence, whereas 85.7 percent had positive skin biopsies. Of the fifteen patients with only skin lesions, 80 percent had positive oral mucosa biopsies by direct immunofluorescence, although the oral cavity was clinically free of disease. A total of 89.6 percent of the patients had positive oral mucosa biopsies, and an equal percentage had positive skin biopsies. IgG was present in the immune deposits in all positive biopsies, and in eight cases C'3 was detected as well. Circulating antibasement membrane zone antibodies were detected in 79.3 percent of the cases when a compound animal substrate was used and in 82.7 percent of the cases when healthy human oral mucosa was used as substrate.