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 α (TNFα) 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 TNFα production by PBMC.