Response to ‘Serum level of adiponectin is a surrogate independent biomarker of radiographic disease progression in early rheumatoid arthritis: results from the ESPOIR cohort’– authors’ reply

  • Eric Toussirot1Email author and

    Affiliated with

    • Gilles Dumoulin2, 3

      Affiliated with

      Arthritis Research & Therapy201416:407

      DOI: 10.1186/ar4537

      Published: 10 April 2014

      We read with great interest the recent article in Arthritis Research & Therapy in which Meyer and colleagues evaluated different circulating adipokines in patients with recent-onset rheumatoid arthritis (RA) [1]. The authors found that total adiponectin was independently associated with baseline radiographic score and with a change in this score over time. The authors concluded that total adiponectin at the time of diagnosis is a surrogate marker for radiographic progression in early RA.

      However, there are some compelling reasons why the role of adiponectin in RA requires further elucidation. The conclusion by Meyer and colleagues should thus be tempered.

      First, several studies have investigated circulating concentrations of leptin, adiponectin, visfatin and resistin in RA, showing, in general, elevated levels. However, the link between these adipose products and disease activity remains controversial.

      Second, both proinflammatory and anti-inflammatory effects of adiponectin have been reported.

      Third, adiponectin exists in various isoforms, monomers and multimers. These different isoforms perform distinct and sometimes counteracting biological functions: low molecular weight adiponectin has been shown to inhibit lipopolysaccharide-mediated IL-6 release and to stimulate IL-10 secretion [2]. Conversely, high molecular weight (HMW) adiponectin induces secretion of IL-6 by monocytes, and increases production of monocyte chemoattractant protein-1 and IL-8 by peripheral blood mononuclear cells and microvascular endothelial cells [3].

      Fourth, in a cross-sectional study, we evaluated total adiponectin and HMW adiponectin in patients with established RA and in healthy controls. We found that circulating HMW adiponectin did not differ between patients and controls, whereas total adiponectin was elevated in the RA group. In addition, total adiponectin and HMW adiponectin did not correlate in this series [4].

      Fifth, adiponectin has been shown to be associated with disease severity or joint destruction in both cross-sectional and longitudinal studies with conflicting results [1]. Moreover, in a murine collagen-induced arthritis model of RA, total adiponectin was shown to attenuate the severity of arthritis [5].

      Finally, studies conducted to date in RA measured exclusively total adiponectin and not its isoforms, and the discrepancies between the findings of these studies may be explained by the distinct biological properties of the different adiponectin isoforms. In this context, no formal conclusion may be drawn about the role of adiponectin in disease activity and severity in RA. Future studies evaluating adiponectin in RA and its relationships with radiographic progression should include assessment of the different adiponectin isoforms.

      Abbreviations

      HMW: 

      High molecular weight

      IL: 

      Interleukin

      RA: 

      Rheumatoid arthritis.

      Declarations

      Authors’ Affiliations

      (1)
      Clinical Investigation Center for Biotherapy, INSERM CBT-506, FHU INCREASE, University Hospital of Besançon
      (2)
      Endocrine and Metabolic Biochemistry, University Hospital of Besançon
      (3)
      UPRES EA 3920 “Cardiovascular Pathophysiology and Prevention”, SFR FED, University of Franche Comté

      References

      1. Meyer M, Sellam J, Fellahi S, Kotti S, Bastard JP, Meyer O, Liote F, Simon T, Capeau J, Berenbaum F: Serum level of adiponectin is a surrogate independent biomarker of radiographic disease progression in early rheumatoid arthritis: results from the ESPOIR cohort. Arthritis Res Ther 2013, 15:R210.PubMed CentralPubMedView Article
      2. Neumeier M, Weigert J, Schaffler A, Wehrwein G, Muller-Ladner U, Scholmerich J, Wrede C, Buechler C: Different effects of adiponectin isoforms in human monocytic cells. J Leukoc Biol 2006, 79:803–808.PubMedView Article
      3. Song H, Chan J, Rovin BH: Induction of chemokine expression by adiponectin in vitro is isoform dependent. Transl Res 2009, 154:18–26.PubMed CentralPubMedView Article
      4. Toussirot E, Grandclement E, Gaugler B, Michel F, Wendling D, Saas P, Dumoulin G: CBT-506: Serum adipokines and adipose tissue distribution in rheumatoid arthritis and ankylosing spondylitis. A comparative study. Front Immunol 2013, 4:453.PubMed CentralPubMedView Article
      5. Lee SW, Kim JH, Park MC, Park YB, Lee SK: Adiponectin mitigates the severity of arthritis in mice with collagen-induced arthritis. Scand J Rheumatol 2008, 37:260–268.PubMedView Article

      Copyright

      © The Author(s) 2014

      This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

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