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

Pemphigus relapse shows a non-random, 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 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.