Site-specific relapse in pemphigus is associated with localized tissue-resident memory T-cell enrichment

Pemphigus relapse shows a nonrandom, site-specific pattern, with recurrent lesions preferentially occurring at previously affected anatomical locations. In a retrospective cohort of 105 patients, we found that spatial overlap between new-onset and relapse sites significantly exceeded random expectation and was independent of circulating autoantibody levels. Recurrent lesions were enriched for CD4+CD69+ and CD8+CD103+ tissue-resident memory T cells, suggesting a role for localized immune memory in disease recurrence.