Carmona-Rivera C, O’Neil LJ, Patino-Martinez E, et al. - In hidradenitis suppurativa (HS), specific IgG autoantibodies exist that recognize circulating and tissue antigens. This observation not only implies an autoimmune mechanism in HS but also unveils putative treatment targets.

• According to previous observation, there exists dysregulation of humoral immune responses in HS.

• Comparison of IgG autoreactivity in HS sera and lesional skin vs those in normal healthy controls was performed.

• Autoantibodies against nuclear antigens, cytokines, cytoplasmic proteins, extracellular matrix proteins, neutrophil proteins, and citrullinated antigens were present, as demonstrated using Cy3-labeled anti–human assay.

• In stages II‒III in HS sera and stage III in HS skin lesions, significantly elevated levels of most of these autoantibodies were seen vs healthy controls.

• Activation of M1 and M2 macrophages can be induced by immune complexes comprising both native and citrullinated versions of antigens, and subsequently proinflammatory cytokines are released.