Serum amyloid A1 and tumor necrosis factor-alpha alleles in Turkish Familial Mediterranean Fever patients with and without amyloidosis

Abstract

The major complication of familial Mediterranean fever (FMF) is AA amyloidosis. The influence of FMF gene (MEFV) mutations and or unknown environmental factors and other genetic modifiers are likely to affect the pheno-typic variations of the disease and the development of amyloidosis. Serum amyloid A is a serum precursor of AA amyloid that is induced by inflammatoy cytokines including TNF-a. Our analysis of SAAI.1 frequency in Turkish FMF-amyloidosis patients, revealed a higher frequency compared to non FMF-amyloidosis patients but the difference was not significant. On the other hand, the distribution of SAAI.1 homozygosity among FMF-amyloidosis patients was 55.5 % compared to FMF-non-amyloidosis patients (30.8 %) which was statistically significant revealing a 2.5 fold risk for the occurrence of amyloidosis. There was no significant difference between the controls and FMF patients with and without amyloidosis for the TNF-α-308 G-A allele. It is worth noting that all TNF-α -308 G-A carriers (n=6) in FMF-amyloidosis group have SAAI.1 homozygosity compared to 2/11 in FMF-non-amyloidosis group. Further evaluation of these polymorphisms may have importance and need further study.

Key Words:

• serum Amyloid A
• tumor necrosis factor- alpha
• familial Mediterranean fever
• amyloidosis