Elevated CD14 Expression in Blood of Patients with Shoulder Osteoarthritis- SOMOS 2025

c brunette, f say, j johnson, b kowalski c gerber, z caolburn, m bedrin, j galvin

Abstracted accepted for a rapid-fire presentation at the 2025 Society of Military Orthopaedic Surgeons Annual Meeting.

Introduction:
Osteoarthritis (OA) is a common degenerative joint disease characterized by the loss of hyaline cartilage integrity, activation of inflammatory cascades, and progressive pain and dysfunction. Although traditionally considered a localized articular process, systemic inflammation has been increasingly implicated in the pathogenesis of OA. The identification of circulating molecular biomarkers may facilitate earlier diagnosis and inform therapeutic strategies. The purpose of this study was to determine whether gene expression profiles in whole blood differ between patients with and without shoulder OA.

Methods:
A prospective, single-center cohort study was conducted in patients (ages 20–65) undergoing elective shoulder surgery at a single institution. Participants were classified into OA (n=5) and non-OA (n=44) groups based on clinical and radiographic criteria. Whole blood was collected using DNA/RNA Shield tubes, and RNA was extracted for analysis. Gene expression was quantified using the NanoString nCounter Inflammation Panel. Statistical analysis was performed using the NanoStringDiff package in R, with adjustments for the relatively small sample size of the OA group.

Results:
Among the genes analyzed, CD14 was the only transcript found to be elevated in the OA group compared to the non-OA group (p = 0.03).

Conclusion:
This preliminary investigation identifies CD14 as a potential systemic biomarker of inflammation in patients with shoulder OA. CD14 encodes a surface glycoprotein primarily expressed on monocytes and macrophages and plays a key role in innate immune activation via lipopolysaccharide (LPS) signaling. Its elevated expression suggests enhanced systemic immune activation in patients with OA. Increased CD14 expression in whole blood may reflect heightened innate immune system activity associated with OA pathophysiology. Further confirmatory studies are warranted to validate CD14 as a diagnostic or prognostic biomarker and to elucidate its mechanistic role in OA.