Circulating levels of interleukin-6, vascular endothelial growth factor, YKL-40, matrix metalloproteinase-3, and total aggrecan in spondyloarthritis patients during 3 years of treatment with TNF alpha inhibitors

S.J. Pedersen, M.L. Hetland, Inge Juul Sørensen, Mikkel Østergaard, H.J. Nielsen, J.S. Johansen

    Abstract

    The objectives of the study were to investigate short and long-term changes and relations to treatment response of plasma interleukin-6 (IL-6), vascular endothelial growth factor (VEGF), YKL-40, matrix metalloproteinase-3 (MMP-3), and total aggrecan in patients with spondyloarthritis (SpA) treated with tumor necrosis factor-alpha (TNF alpha) inhibitors and to compare with levels in healthy subjects. Biomarkers were measured in an observational cohort of 49 SpA patients (ankylosing spondylitis, n = 32, and psoriatic arthritis, n = 17) initiating TNF alpha inhibitor therapy (infliximab, n = 38; etanercept, n = 8; and adalimumab, n = 3) and compared with levels in healthy subjects. Clinical parameters and biomarkers were measured at baseline, weeks 2, 6, and every 6-12 weeks for up to 3 years. Patients with co-morbidities (n = 4), missing baseline samples (n = 3), and adverse events (n = 5) were excluded. Patients with SpA had compared with healthy subjects elevated IL-6 (median 8.5 ng/l (range, 0.98-64) vs. 1.3 (0.33-26)), VEGF (105 ng/l (22-752) vs. 45 (12-351)), YKL-40 (74 mu g/l (14-572) vs. 43 (20-184)), and MMP-3 (43 mu g/l (9.1-401) vs. 16 (2.5-47), p a parts per thousand currency signaEuro parts per thousand 0.001), whereas total aggrecan was lower (662 mu g/l (223-2,219) vs. 816 (399-2,190),p a parts per thousand currency signaEuro parts per thousand 0.001). Two weeks after first treatment, all biomarker levels changed towards normal levels (p a parts per thousand currency signaEuro parts per thousand 0.03) in clinical responders (n = 24), and persistent reductions over 3 years were found in IL-6, VEGF, YKL-40, and MMP-3. Only MMP-3 decreased (p a parts per thousand currency signaEuro parts per thousand 0.02) in non-responders (n = 13). The study demonstrated changes of plasma IL-6, VEGF, YKL-40, MMP-3, and total aggrecan and a potential value for monitoring disease activity and treatment response in SpA patients. Larger prospective studies are required to clarify clinical utility of these biomarkers
    Original languageEnglish
    JournalClinical Rheumatology
    Volume29
    Issue number11
    Pages (from-to)1301-1309
    Number of pages9
    ISSN0770-3198
    Publication statusPublished - 2010

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