Genetics and new treatment modalities for familial Mediterranean fever.

Familial Mediterranean fever (FMF) is the most common of a rare group of disorders collectively termed familial hereditary periodic fever syndromes, also known as autoinflammatory syndromes. FMF is clinically characterized by intermittent bouts of fever with peritonitis and abdominal pain, pleuritis, arthritis, or erysipelas-like rashes. Amyloidosis due to chronic inflammation progressing to renal failure is one of the most serious potential complications of this disease. Individuals with FMF have identifiable genetic defects in the Mediterranean fever (MEFV) gene, which codes for the protein pyrin. Pyrin normally blunts neutrophil-mediated inflammation, likely via interleukin-1 (IL-1) downregulation, but is defective in FMF. Potential treatments include colchicine, with case reports of benefits with catecholamine blockade (prazosin), tumor necrosis factor (TNF) antagonism (etanercept, thalidomide), and IL-1 receptor blockade (anakinra).