Persistence of anti-desmoglein 3 antibodies in patients with pemphigus vulgaris in complete remission is associated with restricted isotype diversity and desmoglein 3 ectodomain recognition

In pemphigus vulgaris, baseline severity and relapse correlate with anti-desmoglein 3 (anti-Dsg3) antibodies targeting ectodomains (ECs), specifically EC1–2 and EC4–5, and involving multiple IgG subclasses (two to three subclasses in 81% of patients). In contrast, patients in complete remission despite persistent anti-Dsg3 autoantibodies show limited EC recognition and predominantly single IgG subclass responses, with lower frequencies of antibody-secreting cells and reduced in vitro keratinocyte dissociation.