Immunocytochemical detection of autoantibody deposits in Tzanck smears from patients with oral pemphigus.

Eighteen patients, ten affected by pemphigus vulgaris and four affected by herpes simplex of the oral mucosa, together with four healthy patients as controls, were investigated by cytologic examination of Papanicolaou stained smears obtained by scraping the oral mucosa. In all cases additional smears were immunostained with the alkaline phosphatase-anti-alkaline phosphatase (APAAP) technique using monoclonal antibodies against human heavy IgG chains and lambda light chains. The results have shown that, for a cytological diagnosis of pemphigus, this technique can be used as an easy substitute for the immunofluorescence test and does not require any specialized training or equipment. The findings are clearly detectable by light microscopy and allow, together with the immunostaining, an adequate visualization of cell morphology.