Antidesmoglein 1 and 3 serum IgG and positivity by direct immunofluorescence microscopy is associated with relapse in pemphigus in a prospective bicontinental study.

BACKGROUND

Prospective studies identifying immunological parameters that can predict clinical relapse in pemphigus are scarce.

OBJECTIVE

To periodically assess immunological parameters in patients with pemphigus vulgaris and foliaceous in remission to understand immunological events preceding clinical relapse.

METHODS

A total of 105 patients were included. Baseline assessment included direct immunofluorescence (DIF), serum IgG against desmoglein (Dsg) 1, IgG, IgG1, and IgG4 against Dsg 3, IgG against the extracellular domains 1 and 2 of Dsg 3, IgG against muscarinic (M3)-AchR, and peripheral CD19+CD27+ memory B cells/plasma cells, repeated every 3 months for up to 12 months or until clinical relapse. DIF was repeated at month 12 and on relapse.

RESULTS

About 29 of 105 patients (28%) experienced a relapse. Longer duration of clinical remission, presence of pruritus and positive anti-Dsg1 at baseline correlated with higher relapse rates. Compared with the visit immediately preceding relapse, a significantly increased number of patients with positive anti-Dsg1 (38% vs 31.1%, P = .01), anti-Dsg3 (51.7% vs 41.4%, P = .01) and IgG positivity by DIF (85.7% vs 25%, P < .001) was observed at the time of relapse.

CONCLUSION

Regular monitoring of anti-Dsg 1 and anti-Dsg 3 serum levels and DIF positivity during the course of the disease in remission may predict relapse.