ABNORMAL VITAMIN-B-6 STATUS IN RHEUMATOID CACHEXIA - ASSOCIATION WITH SPONTANEOUS TUMOR-NECROSIS-FACTOR-ALPHA PRODUCTION AND MARKERS OF INFLAMMATION

Objective. To compare vitamin B-6 levels in rheumatoid arthritis (RA) patients and healthy control subjects. Methods, We measured levels of vitamin B-6 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 B-12 concentrations and erythrocyte B-6 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.