Serum Clusterin Levels in Patients with Rheumatoid Arthritis and its Implication in the Disease Activity and Severity

Background: Rheumatoid arthritis (RA) is a multifactorial autoimmune disease marked by persistent inflammation, Clusterin (CLU) is an 80 kDa glycoprotein that exhibits chaperone-like and cytoprotective functions. Aim: To measure the serum titre of CLU in RA cases and to correlate its titre with the different disease parameters to determine its potential role and implication in the disease activity and severity. Methods: This cross-sectional investigation enrolled 60 participants (30 RA cases and 30 matched controls) from Benha University Hospital's Rheumatology Department. All participants underwent comprehensive clinical evaluation The history assessment covered personal data, present illness characteristics, past medical history, and family history. Physical examination. Disease activity byDAS-28 and VAS scores. Functional disability by HAQ. All participants underwent standardized laboratory testing including inflammatory markers,complete blood count, autoantibody testing, and serum CLU measurement via ELISA. Radiographic evaluation of hands and wrists. Results: There was a non-significant difference between RA cases and controls regarding age (p=0.11). RA cases had median disease duration of 10.5 years, Laboratory assessments revealed elevated inflammatory markers and moderate disease activity Radiological evaluation showed 40% of cases had moderate joint damage, while functional assessment indicated 63.3% maintained normal daily activities .CLU titres were higher in RA cases than control, CLU showed strong negative correlations with disease duration (r=-0.757) and radiographic damage (r=-0.549), but positive associations with disease activity (DAS28 r=0.364) and swollen joint count (r=0.46). Conclusion CLU shows promising potential as a biomarker for differentiating RA from controls, with sensitivity 63.3%, a specificity of 66.7% and a total accuracy 65%.