Research suggests that SARS-CoV-2 infection directly contributes to bone loss in individuals with chronic immune-mediated inflammatory diseases (IMIDs). The findings demonstrate that the SARS-CoV-2 accessory protein ORF8, which mimics IL-17 signalling, intensifies inflammation and accelerates bone resorption. “These findings are significant for patients with IMIDs, as they identify a molecular mechanism through which SARS-CoV-2 exacerbates disease pathology”, notes Weiqiang Chen, one of the corresponding authors of the study.

The researchers first used high-throughput multiplexed proteomics to analyse 1,500 protein biomarkers in plasma samples from four groups of individuals: those with confirmed COVID-19 and a pre-existing IMID (n = 13); those with an IMID but no history of COVID-19 (n = 20); those with confirmed COVID-19 but no history of IMID (n = 20); and healthy control individuals with no history of COVID-19 or IMID (n = 20). The analysis showed that the group with COVID-19 and an IMID had the highest number of differentially expressed proteins, with increased expression of pro-inflammatory cytokines and markers of bone resorption.