[Diagnosis and Clinical Examination of Autoinflammatory Syndrome].

Autoinflammatory syndrome is characterized by: 1) episodes of seemingly unprovoked inflammation, 2) the absence of a high titer of autoantibodies or auto-reactive T cells, and 3) an inborn error of innate immunity. In this decade, many autoinflammatory syndromes have been reported in Japan, and so many Japanese physicians have become aware of this syndrome. Monogenic autoinflammatory syndromes present with excessive systemic inflammation including fever, rashes, arthritis, and organ-specific inflammation and are caused by defects in single genes encoding proteins that regulate innate inflammatory pathways. The main monogenic autoinflammatory syndromes are familial Mediterranean fever (FMF), TNF receptor-associated periodic syndrome (TRAPS), mevalonate kinase deficiency (MKD), cryopyrin-associated periodic syndrome (CAPS), Blau syndrome, and pyogenic arthritis, pyoderma gangrenosum, and acne (PAPA) syndrome. We diagnosed these syndromes as clinical manifestations and performed genetic screening. Many serum cytokines are elevated in patients with autoinflammatory syndrome, but this is not disease-specific. The pathogeneses of many autoinflammatory syndromes are known to be related to inflammasomes, which are multiprotein complexes that serve as a platform for caspase 1 activation and interleukin-1β (IL-1β) and IL-18 muturation. Especially, NLRP3 inflammasomes may play a crucial role in the intiation and progression of FMF and CAPS. In the future, we hope to discover new clinical examinations which can provide evidence of inflammasome activation independent of genetic screening. In this issue, I introduce autoinflammatory syndromes and discuss the diagnosis and clinical examination of these syndromes.