Sclerostin as an innovative insight towards understanding Rheumatoid Arthritis

BackgroundRheumatoid arthritis (RA) is a chronic autoimmune disease characterized by joint inflammation leading to cartilage and local bone erosion. Sclerostin is a protein that in humans has been identified as an inhibitor of the pathway and leads to decreased bone formation.Aim of the workThis study aimed to investigate the level of serum sclerostin in RA patients, its association with inflammatory profile and its relation to disease activity and severity.Patients and methodsThirty-one Egyptian RA patients (28 females, 3 men) participated in this study. Their median age was 40 years. Disease activity score was assessed by the disease activity score (DAS28) and the functional status by the modified health assessment questionnaire (MHAQ). Ten matched controls were also included. Radiological severity was assessed according to the Larsen score. Serum sclerostin was measured.ResultsMedian serum sclerostin in RA patients was 2000 ng/dl (800–3300 ng/dl) which was significantly higher than in controls [210 ng/dl (150–2859)] (Z = −4.47, p < 0.001). Sclerostin significantly negatively correlated with C-reactive protein and DAS28 (p = 0.014 and p = 0.02 respectively) and positively correlated with the Larsen score and total joint count (p = 0.03 and p = 0.02 respectively). At serum level 267 ng/dl sclerostin has sensitivity of 96.8% to diagnose RA and a positive predictive value of 96.6%.ConclusionSerum sclerostin was significantly higher in RA patients than controls and correlated with disease activity and severity which highly suggests that it may play a role in the pathogenesis of RA making it a valuable new marker of monitoring the disease progress and prognosis.