Familial Mediterranean fever and the other autoinflammatory syndromes: evaluation of the patient with recurrent fever.
PURPOSE OF REVIEW: The aim of this article is to summarize recent clinical, genetic and pathophysiologic findings of familial Mediterranean fever and several of the other systemic autoinflammatory diseases, a recently recognized group of disorders characterized by seemingly unprovoked inflammation but lacking high-titer autoantibodies. Genetic and clinical tools are improving the ability of the clinician to better approach patients with periodic fever and inflammation. RECENT FINDINGS: The spectrum of reported genetic mutations and susceptible ethnicities for the hereditary periodic fever subset of the autoinflammatory diseases has continued to expand. At the same time, the pathogeneses of many of these diseases are now understood to involve different aspects of a common pathway, largely affecting inflammatory cascades related to IL-1 or tumor necrosis factor-alpha. Three of these diseases which have been grouped as the cryopyrin-associated periodic syndromes result from defects in the same gene, and all three appear to respond well to anti-IL-1 therapy although controlled trials are still in progress. In addition, cytokine-based therapies are also now under investigation for hyperimmunoglobulinemia D with periodic fever syndrome and pyogenic sterile arthritis, pyoderma gangrenosum, and acne syndrome. SUMMARY: The identification of the genes and proteins mutated in many of the autoinflammatory diseases has broadened our understanding of the regulation of inflammation and the immune system, and provided the basis for the use of targeted therapies in these syndromes. We propose an algorithm for the evaluation of a patient with periodic fever, taking into account the patient's age, ethnicity, symptoms and signs, and results from laboratory and genetic testing.