Comparison of different epithelial substrates useful for indirect immunofluorescence testing of sera from patients with active pemphigus.

A positive statistical correlation between intercellular antibody titer and disease severity was found for a group of 6 patients with active pemphigus vulgaris, irrespective of whether indirect IF testing was performed on 5 different epithelial substrates which included guinea pig esophagus, human foreskin, rabbit esophagus, monkey esophagus and monkey lip. In a group of 4 patients with pemphigus foliaceus a positive correlation between disease severity and titer was found only when rabbit esophagus was used for indirect fluorescence testing. In both groups of patients there were individual patients in whom the antibody titer was positive at a time when no disease was present and conversely, there were some patients in whom the antibody titer was negative at a time when extensive disease was present. Because of this inconsistency, the use of antibody titers to monitor disease activity and therapy in individual patients may not be justifiable.