Increased Serum Concentrations of Homocysteine and Lipoprotein (a) in Familial Mediterranean Fever

Serum homocysteine, folic acid, lipoprotein (a) (Lp(a)), fibrinogen, and C-reactive protein (CRP) concentrations and erythrocyte sedimentation rates (ESR) were measured in 52 patients with familial Mediterranean fever (FMF) during attack-free periods and in 30 healthy control subjects. Serum homocysteine levels were significantly higher in the FMF patients (median 17.8 mu g/dl; range 5.6-80.8) than in controls (median 11.7; range 5.6-42.2; p = 0.013). Serum homocysteine levels were elevated above the upper reference limit (15 mu g/dl) in 56% of the FMF patients compared to 27% of the controls (p = 0.011). Serum Lp(a) levels were significantly higher in the FMF patients (median 39.3 mg/dl; range 6.6-124.5) than in controls (median 27.2; range 11.1-78.1; p = 0.035). Serum Lp(a) levels were elevated above the upper reference limit (30 mg/dl) in 71% of the FMF patients compared to 47% of the controls (p = 0.028). The ESR, fibrinogen, CRP, and folic acid levels were similar in both groups. In conclusion, serum homocysteine and Lp(a) concentrations are often increased in FMF patients during attack-free periods. The elevated homocysteine and Lp(a) levels, which are markers of sub-clinical inflammation, may be mediators of atherosclerotic disease in FMF patients.