IMMUNOHISTOPATHOLOGICAL STUDY OF AUTOIMMUNE PEMPHIGUS - LACK OF STRICTLY SPECIFIC HISTOLOGICAL AND INDIRECT IMMUNOFLUORESCENCE CRITERIA FORPARANEOPLASTIC PEMPHIGUS

Paraneoplastic pemphigus (PNP) is a form of pemphigus considered to be ar characteristic immunohistopathological features (vacuolar-interface dermatitis, keratinocyte dyskeratosis and reactivity of patients' ser a with transitional epithelia). The present study was undertaken in or der to investigate whether these criteria are specific enough so as to allow the diagnosis of PNP in the absence of clinical data. A retrosp ective study of 66 biopsies of pemphigus revealed that one third of th em comprised histological signs of PNP; one of the corresponding sera reacted with mouse bladder epithelium. However, no evidence of a neopl astic disease was present in any of the patients, and Western blotting further excluded the diagnosis of PNP. These results suggest that som e of the features considered characteristic of PNP are not strictly sp ecific for this variety of pemphigus; hence this diagnosis cannot be r eliably established by histology or immunofluorescence but requires bi ochemical studies.