Cartilage Oligomeric Matrix Protein (COMP) and Hyaluronic Acid (HA): Diagnostic Biomarkers of Knee Osteoarthritis

Abstract

Introduction: Osteoarthritis of knee is diagnosed on clinical features, functional and radiological evaluation. More recently biochemical markers are used to diagnose the condition in early stage, to assess the disease progression and efficacy of treatment. Aims & Objectives: The aim of the study is to assess role of serum Cartilage oligomeric matrix protein (COMP) and serum Hyaluronic acid (HA) levels as diagnostic biomarker and burden of disease biomarker in primary knee osteoarthritis. Materials and Methods: Radiographic assessment (K-L grading) and functional assessment (WOMAC score) was done for 100 cases and 50 control subjects. Serum COMP and HA levels were estimated for all the subjects. Results: Mean HA levels in mild cases was 14.07+7.04 ng/ml, in moderate cases was 38.28±41.34 ng/ml and in severe cases was 148.41+133.06 ng/ ml (p<0.001). Mean COMP levels in mild cases was 606.08 ±105.27 ng/dl, in moderate cases it was 702.44±133.16 ng/dl and in severe cases it was 898.24 ±82.09 ng/dl (p<0.001). HA levels show good discriminant ability of between cases and control (sensitivity: 95.0%, specificity: 90.0%), between mild and moderate case (sensitivity: 87.6%, specificity: 86.0%) and between moderate and severe cases (sensitivity: 92.3 %, specificity: 93.1%). COMP show excellent discriminant ability between cases and controls (sensitivity: 98%, specificity: 98.0%), between mild and moderate cases (sensitivity: 92.9%, specificity: 93.2%) and in between moderate and severe cases (sensitivity: 100%, specificity: 97.7 %). COMP estimation shows higher sensitivity, specificity and accuracy as compared to HA as diagnostic and burden of disease biomarker.