Serum Sclerostin Level Among Egyptian Rheumatoid Arthritis Patients: Relation to Disease Activity ,Bone Mineral Density and Radiological Grading

Introduction: Bone loss in rheumatoid arthritis is caused by increased bone resorption without increasing bone formation. The Wnt pathway is important in the control of bone formation through the regulation of osteoblast activity. Sclerostin is an important regulator of the Wnt pathway by blocking Wnt binding to its receptor and thereby inhibiting bone formation. Aim: This study aimed to assess the serum sclerostin level in a group of Egyptian rheumatoid arthritis patients and to correlate its level with bone mineral density, disease activity and radiological grading. Methods: Forty rheumatoid arthritis patients (mean age 48.9 ± 11.6 years, disease duration 8 ± 6.4 years) and 40 age and sex matched apparently healthy subjects were included. Serum sclerostin level was measured using Enzyme linked Immunosorbent Assay. Plain radiographs of hands and feet and dual-energy x-ray absorptiometry test were done for all patients. Results: No significant difference was found between rheumatoid arthritis patients and healthy controls as regard mean value of sclerostin level. Postmenopausal healthy women had higher levels of sclerostin than premenopausal healthy women only. Serum sclerostin had significantly positive correlations with the age of onset and weight of rheumatoid arthritis patients and negative correlation with Erythrocyte Sedimentation Rate. No correlation was encountered between sclerostin level and bone mineral density, disease activity or radiographic grading. Conclusion: For better clarification of the role of sclerostin on bone mass in rheumatoid arthritis, larger sample size is needed. More studies on serum sclerostin levels among different grades of RA activity are encouraged.