Plasma total homocysteine level and methylenetetrahydrofolate reductase 677C>T genetic polymorphism in Japanese patients with rheumatoid arthritis

Abstract

Hyperhomocysteinemia is a known risk factor of cardiovascular disease. Homocysteine has been also linked to inflammation in rheumatoid arthritis (RA). In this study, we investigated the relationship between plasma homocysteine levels and single nucleotide polymorphism (SNP) of the gene coding for methylenetetrahydrofolate reductase (MTHFR), an enzyme involved in the biosynthesis of homocysteine, and the correlation between the plasma homocysteine levels and generally used inflammatory markers (C-reactive protein, erythrocyte sedimentation rate and matrix metalloproteinase-3) in 96 Japanese patients with RA. Plasma homocysteine levels in patients with the MTHFR 677TT genotype were significantly higher than in those with the 677CC genotype (p < 0.05). In addition, plasma homocysteine levels were increased along with the elevation of general inflammatory markers. Therefore, we conclude that homocysteine might affect the inflammatory status of patients, and the MTHFR 677C>T SNP could be a predictive factor of hyperhomocysteinemia in patients with RA.

Keywords::

• Homocysteine
• inflammation
• methylenetetrahydrofolate reductase
• rheumatoid arthritis
• single nucleotide polymorphism

Acknowledgements

The authors gratefully thank Mr Naoto Harada at the University of Shizuoka, and Dr Osamu Kimoto, Ms Chiharu Kuroda and the professional nurses at Shizuoka Kousei Hospital for their medical expertise. This study was supported in part by Grant-in-Aid for Young Scientists (B) (No. 20790140 to HH) from the Ministry of Education, Culture, Sports, Science and Technology, Japan.

Declaration of interest: There is no commercial or proprietary interest on any product or company.