Abnormal vitamin b₆status in rheumatoid cachexia association with spontaneous tumor necrosis factor α production and markers of inflammation

Abstract

OBJECTIVE: To compare vitamin B6 levels in rheumatoid arthritis (RA) patients and healthy control subjects. METHODS: We measured levels of vitamin B6 in 23 adults with well-controlled RA, and in 23 healthy control subjects matched for age, sex, race, and weight. RESULTS: Although plasma folate and vitamin B12 concentrations and erythrocyte B6 activity coefficients were similar in the patients and controls, plasma levels of pyridoxal-5'-phosphate (PLP) were lower in the RA patient group (mean +/- SD 46.1 +/- 48.1 versus 69.3 +/- 58.4 nmoles/liter; P < 0.004). In multivariate analyses, PLP was inversely associated with tumor necrosis factor alpha (TNF alpha) production by peripheral blood mononuclear cells (PBMC) (P < 0.001), after adjustment for age, pain score, erythrocyte sedimentation rate, and use of nonsteroidal antiinflammatory drugs. CONCLUSION: PLP levels are reduced in patients with RA. This reduction is associated with TNF alpha production by PBMC.