Autoinflammatory Diseases: A Review

Autoinflammatory disease (AID) is a vast spectrum of disorders characterized by recurrent attacks of sterile inflammation. Since the first cloning of the familial Mediterranean fever gene in 1997, there has been a rapid rate of discovery of new AIDs. As of 2022, there have been 485 inborn errors of immunity documented by the International Union of Immunological Societies, for which many display aspects of autoinflammation. The pathophysiology of AIDs is complex. Although many are caused by rare mutations in genes that govern innate immunity, others are polygenic, where disease expression is thought to be triggered by environmental factors in genetically predisposed hosts. AIDs range in prevalence from common entities like gout to ultrarare monogenic diseases. Whereas AIDs were initially studied in pediatric populations, it is now apparent that they can present in adulthood and even in the elderly. AIDs can be clinically challenging given their rarity, as well as the heterogeneity in presentation and underlying etiology. Although the care of AIDs can span medical disciplines, the rheumatologist often plays a central role given the inflammatory nature of these illnesses. In this review, we explore the current understanding of the pathophysiology of these complex conditions and propose a classification system for AIDs. We place an emphasis on AIDs that present to the adult rheumatologist and discuss important AIDs that can mimic more classic rheumatic diseases such as systemic lupus erythematosus and inflammatory arthritis. Finally, we offer an approach to the clinical assessment, diagnosis, and management of AIDs.