Familial Mediterranean fever-associated renal amyloidosis: case report and review of the literature

Familial Mediterranean fever (FMF) is a hereditary autoinflammatory disease, which is diagnosed especially in Mediterranean patients, but is a rare disorder in our geographical area. Due to its rarity and symptoms consisting mainly in recurrent episodes of fever and serositis, it may be mistaken with other, more frequent diseases, especially acute abdomen and systemic rheumatic diseases. The most important lifethreatening complication is secondary amyloidosis, which usually affects kidneys, with proteinuria up to nephrotic syndrome and chronic kidney disease progressing to end-stage renal disease requiring dialysis or transplantation. In patients with suspected amyloidosis, kidney biopsy or submucosal rectal biopsy are the methods of choice for diagnosis. Kidney biopsy is also useful in patients with FMF who start to develop proteinuria, since other non-amyloid glomerular involvement may appear in FMF. Colchicine is now the gold standard for treatment, not only to reduce the frequency of attacks but also to improve renal prognosis. For this reason, the sooner the diagnosis is established the better the prognosis will be since the patient will benefit from the appropriate treatment with Colchicine. We present the case of a young female patient diagnosed through kidney biopsy with amyloid A (AA) amyloidosis after 30 years of evolution of FMF and we review the present knowledge regarding the pathogenesis and management of this rare genetic disease.