Curr Rheumatol Rep 19 (7): 41, 2017. doi: 10.1007 / s11926 - 017 - 0670 - 8 Complications of familial Mediterranean fever The most significant long-term complication of FMF is Chronic renal failure caused by deposition of amyloid protein in the kidneys Amyloid may also be deposited in the gastrointestinal tract, liver, spleen, heart, testes, and thyroid.