Turesson, Carl

Abstract Objective The aim of this study was to investigate the relationship between biomarkers associated with metabolism and subsequent development of GCA. Method Participants in the population-based Malmö Diet Cancer Study (MDCS; N = 30 447) who were subsequently diagnosed with GCA were identified in a structured process. Matched GCA-free controls were selected from the study cohort. Baseline plasma samples were analysed using the antibody-based OLINK proteomics metabolism panel (92 metabolic proteins). Analyses were pre-designated as hypothesis-driven or hypothesis-generating. In the latter, principal component analysis was used to identify groups of proteins that explained the variance in the proteome. Results There were 95 cases with a confirmed incident diagnosis of GCA (median 12.0 years after inclusion). Among biomarkers with a priori hypotheses, adhesion G protein-coupled receptor E2 (ADGRE2) was positively associated [odds ratio (OR) per S.D. 1.67; 95% CI 1.08–2.57], and fructose-1,6-bisphosphatase 1 (FBP1) was negatively associated (OR per S.D. 0.59; 95% CI 0.35–0.99) with GCA. In particular, ADGRE2 levels were associated with subsequent GCA in the subset sampled <8.5 years before diagnosis. For meteorin-like protein (Metrnl), the highest impact on the risk of GCA was observed in those patients sampled closest to diagnosis, with a decreasing trend with longer time to GCA (P = 0.03). In the hypothesis-generating analyses, elevated levels of receptor tyrosine-like orphan receptor 1 (ROR1) were associated with subsequent GCA. Conclusion Biomarkers identified years before clinical diagnosis indicated a protective role of gluconeogenesis (FBP1) and an association with macrophage activation (ADGRE2 and Metrnl) and proinflammatory signals (ROR1) for development of GCA.

Abstract Objective To investigate the relation between biomarkers of inflammation and subsequent development of GCA. Method Participants in the population-based Malmö Diet Cancer Study (MDCS; N = 30 447), established 1991–96, who were subsequently diagnosed with GCA, were identified in a structured process. GCA-free controls, matched for sex, year of birth and year of screening were selected from the study cohort. Baseline plasma samples were analysed using the antibody-based OLINK proteomics inflammation panel (92 inflammatory proteins). Analyses were pre-designated as hypothesis-driven or hypothesis-generating. In the latter, principal component analysis was used to identify groups of proteins that explain the variance in the proteome. Within components selected based on eigenvalues, proteins with a factor loading of >0.50 were investigated. Results Ninety-four cases with a confirmed incident diagnosis of GCA (median 11.9 years after inclusion) were identified. Among biomarkers with a priori hypotheses, IFN-γ was positively associated with GCA [odds ratio (OR) per s.d. 1.52; 95% CI 1.00, 2.30]. Eight biomarkers in the hypothesis-generating analyses were significantly associated with development of GCA. Among these, higher levels of IFN-γ (OR 2.37; 95% CI 1.14, 4.92) and monocyte chemotactic protein 3 (MCP3) (OR 4.27; 95% CI 1.26, 14.53) were particularly associated with increased risk of GCA in the subset sampled <8.5 years before diagnosis. Several other proteins known to be important for T cell function were also associated with GCA in these analyses, e.g. CXCL9, IL-2, CD40 and CCL25. Conclusion Elevated IFN-γ levels were found years prior to diagnosis of GCA. T cell activation may precede the clinical onset of GCA.