Beyond the skin: B cells in pemphigus vulgaris, tolerance and treatment.

Pemphigus vulgaris (PV) is a rare autoimmune bullous disease characterized by blistering of the skin and mucosa owing to the presence of autoantibodies against the desmosome proteins desmoglein 3 and occasionally in conjunction with desmoglein 1. Fundamental research into the pathogenesis of PV has revolutionized its treatment and outcome with rituximab, a B-cell-depleting therapy. The critical contribution of B cells to the pathogenesis of pemphigus is well accepted. However, the exact pathomechanism, mechanisms of onset, disease course and relapse remain unclear. In this narrative review, we provide an overview of the fundamental research progress that has unfolded over the past few centuries to give rise to current and emerging therapies. Furthermore, we summarize the multifaceted roles of B cells in PV, including their development, maturation and antibody activity. Finally, we explored how these various aspects of B-cell function contribute to disease pathogenesis and pave the way for innovative therapeutic interventions.