Objective: we aimed to study systemic sclerosis patients in order to assess osteoprotegerin/Receptor activator of nuclear factor-kB ligand (OPG/RANKL) system and find the relation of these biomarkers with the clinical features of the disease, the carotid intima thickness, markers of inflammation, lipid profile, and other laboratory characteristics. Methods: both the level of (RANKL), (OPG) in sera of participants, in 30 (SSc) patients and the atherosclerotic changes affecting the common carotid artery were measured and, were compared to 30 healthy controls matched for age and sex. All participants were assessed clinically and subjected to the Revised Medsger SSc severity scale and underwent carotid Doppler ultrasound examination. Results: OPG, RANKL, and RANKL/OPG were 1.9 ± 0.4 ng/ml, 24.3 ± 17.25 ng/ml, and 13.5 ±9.8 versus 0.77 ± 0.25 ng/ml, 7.13 ± 3.02 ng/ml, and 9.6 ± 3.1 in the SSc patients and the controls with significance (P = 0.001, P = 0.001, P = 0.045) respectively. The OPG- RANKL axis in the SSc patients correlated significantly with carotid intima thickness, arthritis, arthralgia, inflammatory markers, Medsger joint, Medsger vascular, Medsger skin, and dyslipidemia. Conclusion: In cardiovascular risks, OPG serum level might increase as a preventive compensatory mechanism to neutralize the RANKL level increment. The determination of the OPG-RANKL system is a diagnostic indicator for the intensity of vascular calcification and atherosclerosis in SSc patients.
