A clinical guide to autoinflammatory diseases: familial Mediterranean fever and next-of-kin.

Autoinflammatory diseases are associated with abnormal activation of the innate immune system, leading to clinical inflammation and high levels of acute-phase reactants. The first group to be identified was the periodic fever diseases, of which familial Mediterranean fever (FMF) is the most common. In FMF, genetic results are not always straightforward; thus, flowcharts to guide the physician in requesting mutation analyses and interpreting the findings are presented in this Review. The other periodic fever diseases, which include cryopyrin-associated periodic syndromes (CAPS), TNF receptor-associated periodic syndrome (TRAPS) and mevalonate kinase deficiency/hyperimmunoglobulin D syndrome (MKD/HIDS), have distinguishing features that should be sought for carefully during diagnosis. Among this group of diseases, increasing evidence exists for the efficacy of anti-IL-1 treatment, suggesting a major role of IL-1 in their pathogenesis. In the past decade, we have started to learn about the other rare autoinflammatory diseases in which fever is less pronounced. Among them are diseases manifesting with pyogenic lesions of the skin and bone; diseases associated with granulomatous lesions; diseases associated with psoriasis; and diseases associated with defects in the immunoproteasome. A better understanding of the pathogenesis of these autoinflammatory diseases has enabled us to provide targeted biologic treatment at least for some of these conditions.