Detailed profiling of anti-desmoglein autoantibodies identifies anti-Dsg1 reactivity as a key driver of disease activity and clinical expression in pemphigus vulgaris.

With their near-universal presence in patients and ease of clinical measurement, anti-desmoglein (Dsg) antibodies serve as primary candidates for creating prognostic tools in Pemphigus vulgaris (PV). Although the desmoglein compensation hypothesis postulates a clear relationship between anti-Dsg autoantibodies and clinical phenotype in PV, recent studies have questioned the fidelity of this hypothesis as a predictor of lesion morphology. Moreover, few studies address the association of anti-Dsg antibodies to other clinical parameters such as disease phase and age at onset. Using the largest patient repository to date in PV, we present a detailed analysis of anti-desmoglein antibody profiles across a comprehensive range of dynamic (disease phase, therapy, lesion morphology) and temporal (disease duration, age at sampling, age at onset) clinical parameters. Our data highlight the non-traditional but key role of anti-Dsg1 levels in tracking disease activity. We show that declining anti-Dsg1 levels may predict progression from active phase to early remission and long-term maintenance of remission, regardless of lesion morphology. In contrast, many remittent patients have elevated levels of anti-Dsg3 without lesional activity. Furthermore, we describe a unique subset of remittent patients that develop chronic transient lesions (lasting <1 week) in the setting of elevated anti-Dsg3 levels but do not meet the consensus criteria for active phase. Re-classification of patients with transient lesions as "active" may shed new light on pathophysiological processes underlying cycles of blister formation and rapid spontaneous healing in PV. Additionally, we provide evidence for the potential attenuation of the immune response with prolonged disease duration. Our data fit into the broader effort of immunoprofiling to promote data-informed decision-making regarding diagnosis, prognosis and treatment of complex diseases.