Familial Mediterranean Fever

At a glance

Genetically transmitted disorder characterized by recurrent episodes of fever with abdominal pain, arthritis, or pleurisy.

Synonym

Recurrent Polyserositis Syndrome.

Incidence

Incidence is higher in the Mediterranean population. Carrier state can be as high as 1:5 in at-risk population (Sephardic Jews, Armenians, Arabs, Turks).

Genetic inheritance

Autosomal recessive. The syndrome is caused by missense mutations in the MEFV gene located on chromosome 16 leading to alteration in the shape of the pyrin (or marenostrin) protein, exclusively found in granulocytes, which is thought to activate the biosynthesis of a chemotactic-factor inactivator.

Pathophysiology

Affected patients lack a specific protease that is usually present in serosal fluids and that normally inactivates interleukin-8 and the chemotactic complement factor 5a inhibitor. It is believed that it accumulates and causes exaggerated inflammatory response.

Diagnosis

Based on the clinical course and the presence of elevated C-reactive protein, erythrocyte sedimentation rate, fibrinogen, serum amyloid A, and leukocyte count during an acute episode but are nonspecific. Usually there is no increase in platelets. The diagnosis usually is made at age approximately 5 years and almost always before age 20 years.

Clinical aspects

Familial Mediterranean fever (FMF) is characterized by recurrent episode of fever, serositis, oligoarticular arthritis, and rash, beginning between the ages of 5 and 15 years and tending to occur every 2 to 4 weeks. Abdominal pain of short duration is present in 90% of patients and represents acute peritonitis. Peritoneal adhesions may form and cause small-bowel obstruction. Acute scrotal pain may be a manifestation of FMF and should be distinguished from testicular torsion. Pleuritis occurs in approximately 30% of cases and can lead to recurrent atelectasis. Monoarticular arthritis involving large joints is present in up to 70% of patients. The most serious complication of FMF is amyloidosis of the AA type, which can lead to renal failure and death. Splenomegaly is a common complication of amyloidosis; other organs are rarely involved. Amyloidosis is mostly prevalent among Sephardic Jews. Symptoms of an acute attack appear suddenly and last from a few hours up to 96 hours. The disease has a variable and unpredictable course in each patient. Prophylactic therapy with colchicine prevents inflammatory attacks and the development of amyloidosis. The therapy should be continued throughout pregnancy and during lactation as long-term follow-up does not reveal any adverse effect on the children. The association of FMF with seronegative spondyloarthropathies remains controversial.

Precautions before anesthesia

Laparotomy during an acute episode should be avoided because it might cause a flare-up of the disease. Evaluate renal function and test for the presence of proteinuria. Test electrolytes and acid-base status if severe renal failure is diagnosed. If patient ...