Association between serum levels of growth differentiation factor-15 and rheumatoid arthritis activity

Background Growth differentiation factor-15 (GDF-15), also known as macrophage inhibitory cytokine-1, is a member of the transforming growth factor-beta superfamily involved in macrophage regulation. Its exact role in inflammation and tissue repair remains unclear. Aim To evaluate GDF-15 as a biomarker for rheumatoid arthritis (RA) activity and compare its levels between patients and healthy controls. Patients and methods A case–control study included 50 RA patients (>18 years, both sexes) diagnosed clinically and radiologically, and 38 healthy controls. Serum GDF-15 levels were measured in all participants. Results GDF-15 levels were significantly higher in RA patients than controls. A negative correlation was found with creatinine ( P <0.05), while positive correlations were observed with disease activity score 28-erythrocyte sedimentation rate, C-reactive protein, erythrocyte sedimentation rate, anti-cyclic citrullinated peptide, and platelet count. At a cut-off value more than 66.9 ng/l, GDF-15 showed 96.0% sensitivity and 92.11% specificity for distinguishing RA patients from healthy individuals. Conclusion GDF-15 correlates positively with RA disease activity markers and may serve as a reliable biomarker for identifying active disease and differentiating patients from healthy controls.