Clinical, Serologic, and Histopathologic Features of Patients With Pemphigus With Either Positive or Negative <scp>IgG4</scp> Intercellular Deposition by Direct Immunofluorescence (<scp>DIF</scp>): A Retrospective Case–Control Study of 55 <scp>DIF</s

For pemphigus, DIF IgG4 status correlated with ocular involvement, the clinical morphology selected for biopsy, the likelihood of detecting circulating desmoglein antibodies, the presence of specific histopathologic features such as acantholysis and lichenoid inflammation, and the likelihood of having a final diagnosis of PNP. Further studies are needed to determine whether the presence of tissue-bound intercellular IgG4 antibodies correlates with particular disease variants or lesion-specific characteristics.