Background and Aims

Pemphigus Vulgaris is an autoimmune disease associated with pathogenic autoantibodies which recognize skin adhesion proteins called desmogleins. Treatment of pemphigus patients with systemic corticosteroids and/or immunosuppressive drugs improve their condition, which is usually associated with a decrease in serum anti-desmoglein autoantibody titers. However, few patients still have persistent serum anti-desmoglein antibodies after treatment, while being in clinical remission (CR).

The aim of this study was to determine whether or not anti-desmoglein autoantibodies detected in the serum from pemphigus patients in CR were pathogenic, and to compare their pathogenic activity with anti-desmoglein autoantibodies (Ab) detected in these patients’sera during the active phase of the disease.

Methods

Pathogenic activity of autoantibodies was measured in vitro on immortalized keratinocytes by immunofluorescence and dissociation assays.

Results

Some patients remained in CR until the end of the study whereas others relapsed. All serum samples, even those collected from patients in CR, had high anti-Dsg3 Ab titers measured by ELISA.

Incubation with the patients’ IgG collected during the active phase of the disease induced a decrease of desmoglein 3 expression on keratinocytes and a disorganization of cytoskeleton revealed by flotilin 2 staining measured by immunofluorescence and a loss of keratinocyte adhesion measured by dissociation assay. The same experiments performed with IgG from patients who further relapsed showed a pathogenic activity. In contrast, the IgG from patient with persistent CR did not induce any pathogenic effect.

Conclusions

Our results showed a differential pathogenic effect of IgG from patients in CR depending on whether patients will further relapse or not.