Vitamin B-6 Status Correlates with Disease Activity in Rheumatoid Arthritis Patients During Treatment with TNFα Inhibitors. Issue 5 (3rd May 2019)

• Record Type: Journal Article
• Authors: Sande, Jon Sigurd; Ulvik, Arve; Midttun, Øivind; Ueland, Per M; Hammer, Hilde B; Valen, Merete; Apalset, Ellen M; Gjesdal, Clara G
• Is Part Of: Journal of nutrition. Volume 149:Issue 5(2019)
• Page Start: 770
• Page End: 775
• Publication Date: 2019-05-03
• Subjects: pyridoxal 5′-phosphate -- 3-hydroxykynurenine: xanthurenic acid ratio -- functional vitamin B-6 status -- rheumatoid arthritis -- TNFα inhibitors; Nutrition -- Periodicals; Diet -- Periodicals; 613.205
• DOI: 10.1093/jn/nxz001
• Languages: English
• ISSNs: 0022-3166

Abstract

ABSTRACT: Background: A frequent observation in inflammatory conditions, including rheumatoid arthritis (RA), is low circulating amounts of pyridoxal 5′-phosphate (PLP), the metabolically active form of vitamin B-6. Recently, a functional marker of vitamin B-6 status, the ratio of 3-hydroxykynurenine (HK): xanthurenic acid (XA) in plasma (HK: XA), was proposed. Objective: We investigated vitamin B-6 status in patients with RA before and after established treatment with TNFα inhibitors. Methods: We performed a longitudinal study of RA patients ( n = 106, 36% men, median age 54 y) starting first treatment with a TNFα inhibitor (infliximab, etanercept, adalimumab, golimumab, or certolizumab). Clinical assessment (Disease Activity Score for 28 standard joints, DAS28), joint ultrasonography, and blood draw were performed at baseline and after 3 mo treatment. Plasma concentrations of PLP, HK, and XA were measured by liquid chromatography–tandem mass spectrometry. Associations of changes in vitamin B-6 markers with change in DAS28 were assessed by generalized additive models regression and with European League Against Rheumatism (EULAR) response categories by linear regression. Results: At baseline PLP was inversely correlated with CRP (ρ = −0.27, P = 0.007), whereas HK: XA correlated with DAS28 (ρ = 0.46, P < 0.001), CRP (ρ = 0.36, P < 0.001), and ultrasonography scores (ρ = 0.29–0.35, P ≤ 0.003). After 3 mo treatment, the change (a 33% overall reduction) in DAS28 was related to changes in both PLP (ß = −0.28, P = 0.01) and HK: XA (ß = 0.33, P < 0.001). Good responders (45%) according to EULAR criteria experienced a 31% increase in PLP ( P = 0.003) and an 11% decrease in HK: XA ( P = 0.1), whereas nonresponders (24%) experienced a 25% increase in HK: XA ( P = 0.02). Conclusion: Two independent measures of vitamin B-6 status confirm an association with disease activity in RA patients. The association of HK: XA with disease activity may also imply perturbations in kynurenine metabolism in RA. This trial was registered at helseforskning.etikkom.no as 2011/490.