In OA assessment, which inflammatory marker is more specific and sensitive?

• A. C-reactive protein
• B. Erythrocyte sedimentation rate
• C. White blood cell count
• D. Rheumatoid factor

Answer: (A)

C-reactive protein is a sensitive marker of acute inflammation that rises quickly in response to inflammatory activity and falls as inflammation resolves, making it a more reliable indicator of active inflammation in osteoarthritis when present. It tends to track disease activity and response to treatment better than the erythrocyte sedimentation rate, which changes more slowly and is influenced by many non-inflammatory factors like age, anemia, and pregnancy, reducing its specificity. White blood cell count usually stays normal in OA unless there’s infection or another inflammatory process, so it’s not a good marker for OA activity. Rheumatoid factor is associated with rheumatoid arthritis rather than OA, so it isn’t useful for assessing OA. Therefore, CRP is the best choice among these for detecting inflammatory activity in OA.