Bone metabolism and inflammatory biomarkers in radiographic and non-radiographic axial spondyloarthritis patients: a comprehensive evaluation

Front Endocrinol (Lausanne). 2024 Feb 15:15:1227196. doi: 10.3389/fendo.2024.1227196. eCollection 2024.

Abstract

Introduction: Axial spondyloarthritis (axSpA) is a heterogeneous disease that can be represented by radiographic axSpA (r-axSpA) and non-radiographic axSpA (nr-axSpA). This study aimed to evaluate the relationship between the markers of inflammation and bone turnover in r-axSpA patients and nr-axSpA patients.

Methods: A cross-sectional study included 29 r-axSpA patients, 10 nr-axSpA patients, and 20 controls matched for age and sex. Plasma markers related to bone remodeling such as human procollagen type 1 N-terminal propeptide (P1NP), sclerostin, tartrate-resistant acid phosphatase 5b (TRACP5b), receptor activator of nuclear factor kappa B ligand (RANKL), and osteoprotegerin (OPG) were measured by an ELISA kit. A panel of 92 inflammatory molecules was analyzed by proximity extension assay.

Results: R-axSpA patients had decreased plasma levels of P1NP, a marker of bone formation, compared to controls. In addition, r-axSpA patients exhibited decreased plasma levels of sclerostin, an anti-anabolic bone hormone, which would not explain the co-existence of decreased plasma P1NP concentration; however, sclerostin levels could also be influenced by inflammatory processes. Plasma markers of osteoclast activity were similar in all groups. Regarding inflammation-related molecules, nr-axSpA patients showed increased levels of serum interleukin 13 (IL13) as compared with both r-axSpA patients and controls, which may participate in the prevention of inflammation. On the other hand, r-axSpA patients had higher levels of pro-inflammatory molecules compared to controls (i.e., IL6, Oncostatin M, and TNF receptor superfamily member 9). Correlation analysis showed that sclerostin was inversely associated with IL6 and Oncostatin M among others.

Conclusion: Altogether, different inflammatory profiles may play a role in the development of the skeletal features in axSpA patients particularly related to decreased bone formation. The relationship between sclerostin and inflammation and the protective actions of IL13 could be of relevance in the axSpA pathology, which is a topic for further investigation.

Keywords: Interleukin 13; biomarkers; bone metabolism; inflammation; radiographic axial spondyloarthritis; sclerostin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biomarkers
  • Cross-Sectional Studies
  • Humans
  • Inflammation / diagnostic imaging
  • Interleukin-13
  • Interleukin-6
  • Non-Radiographic Axial Spondyloarthritis*
  • Oncostatin M

Substances

  • Oncostatin M
  • Interleukin-13
  • Interleukin-6
  • Biomarkers

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This work was funded by Instituto Salud Carlos III (ISCIII; PI19/00701), co-funded by the European Regional Development Fund (ERDF), and Junta de Andalucía (grant number PI0151-2018). PR-L was supported by a “Miguel Servet” postdoctoral contract (CP22/00096) by the ISCIII-Madrid (Spain) and co-funded by the European Union. JMD-T was supported by a “Sara Borrell” postdoctoral contract (CD19/00055) by the ISCIII-Madrid (Spain), co-funded by the ERDF. GP-L was supported by the Institute of Health Carlos III (project IMPaCT-Data, exp. IMP/00019), co-funded by the European Union, European Regional Development Fund (ERDF, “A way to make Europe”). IM-I was supported by the “Miguel Servet Type II” program (CPII21/00013) of the ISCIII-Madrid (Spain) and co-funded by the European Union.