ABSTRACT
Pemphigus is a group of chronic cutaneous autoimmune diseases that are characterized by blistering of skin and mucous membranes, epidermal cell-cell detachment, also termed acantholysis, and IgG autoantibodies directed against desmosomal antigens (1-4). There are five major forms of pemphigus: 1) Pemphigus vulgaris (PV) and its variant, pemphigus vegetans; 2) pemphigus foliaceus (PF) and its variant, Brazilian pemphigus foliaceus, fogo selvagem (FS); 3) pemphigus erythematosus; 4) drug-induced pemphigus, and 5) paraneoplastic pemphigus. The autoantibodies are important diagnostic and pathological markers of these diseases. Several passive transfer experiments have convincingly demonstrated that the IgG fraction from PV and PF sera reproduce the key clinical, histological and immunological features of humans in neonatal mice (5,6). The autoantigens targeted by PV and PF autoantibodies have been well characterized at the molecular level, however, the etiology of these diseases remains unclear. PV and PF are strongly associated with certain MHC II alleles, hence, it is thought that genetic predisposition plays an important role in the development of these diseases (7-9). Recently, we have demonstrated that T cells from patients with PV and PF react with the same desmosomal antigens that are recognized by the autoantibodies produced by the patients. This observation indicates that self-reactive T lymphocytes are also important elements in the pathogenesis of these diseases (10,11). Since PV and PF account for the majority of patients with pemphigus and most of the current research is devoted to explore the pathogenesis of these diseases, this chapter will focus on recent advances in the understanding of these two autoimmune disorders.
