Sensitivity of indirect immunofluorescence test in the diagnosis of pemphigus

Indirect immunofluorescence testing of sera from patients with pemphigus produces a positive intercellular staining on a variety of epithelial substrates with different sensitivity. We aimed to determine the sensitivity of indirect immunofluorescence (IIF) test in detecting pemphigus antibodies, using two different substrates: guinea pig lip and human skin. IIF detected antibodies in 66 out of 109 patients with different types of pemphigus. Sensitivity of IIF performed with guinea pig lip was 40%, while with human skin it increased to 69%. However, we found that neither human skin nor guinea pig lip was sensitive enough to make an IIF test reliable for the diagnosis of pemphigus.