Familial Mediterranean Fever (FMF) is an inherited auto inflammatory disease (ethnicity-specific). In fact, FMF targets the masses of the Mediterranean region such as Arabs, Armenians, Turkish, Jewish, North African, Italian and Greeks. To clarify, it is an autosomal recessive disease where the genetic mutation is at the level of MEFV gene on the short arm of chromosome 16, which encodes an immune regulatory protein called “pyrin”.
What does familial Mediterranean fever cause?
Familial Mediterranean Fever is of 2 phenotypes. Firstly, phenotype 1 cause short repeated fever episodes and serositis. As a matter of fact, serositis refers to serous tissue inflammation (pericardium, pleura and peritoneum) and their organs. Besides, amyloidosis occurs as a worst-case complication of this disorder, where the protein named amyloid is formed from several proteins and accumulates in the patient’s organs. Thus, this build up leads to renal failure. Secondly, phenotype 2 shows amyloidosis as the first symptom of the disorder.
Major symptoms of familial Mediterranean fever:
-Increased erythrocyte sedimentation rate (ESR)
-Elevated serum fibrinogen concentration
|Minor Features||Normal Values|
|Erythrocyte sedimentation rate (ESR)|| For women:|
<50 years: <20 mm/hr
50-85 years: <30 mm/hr
<50 years: <15 mm/hr
50-85 years: <20 mm/h
|Leukocytosis||4.5-11 × 103µL|
|Serum fibrinogen concentration||200-400 mg/dl|
The diagnosis clinical criteria for FMF are Tel-Hashomer clinical criteria. Meanwhile, if uncertainty takes place, molecular testing for bi-allelic MEFV pathogenic variants decides the diagnosis. Furthermore, if molecular testing didn’t give a perfect result, colchicine is used for 6-months trial as a final resort. In other words, colchicine provides conclusive result since it reliefs from the fever attacks.
Basically, there is no cure for FMF yet. However, colchicine stops the inflammatory attacks and accumulation of amyloid. In fact, a lifelong treatment with colchicine is required (1-2 mg/day orally for adults, 0.5-1 mg/day for children according to weight and age). When FMF is intolerant, interleukin (IL)-1 antagonists are used as a second treatment. Finally, anakinra and canakinumab are given to colchicine resistant patients.
Who would get the diseases?
If you have the following conditions, you are more likely to get Familial Mediterranean Fever (FMF):
-A first degree relative who has FMF
-Belong to an ethnic group with a high-risk of having FMF
-Positive response to colchicine treatment
-Repeated febrile episodes along with peritonitis, synovitis, or pleuritis
-Repeated erysipelas-like erythema
-Recurrent laparotomies for acute abdomen with no pathology detected
-AA type amyloidosis that starts after the age of 15 years in untreated patients.
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