Hidden aspects of inflammation in radiographic knee osteoarthritis

Abstract

Primary osteoarthritis (OA) is known historically to be a non inflammatory condition but recent observations indicate that a low grade inflammation is encountered in pathophysiology of OA's symptoms and progression. We enrolled 150 female patients aged between 50-70 years old diagnosed as OA. Exclusion criteria were any recent infection, trauma, and proved rheumatologic disease. Bilateral standing knee joint radiography was taken and all were categorized according to Kellgren and Lawrence scale. Markers of inflammation consisting of ESR (1st hour), CRP, Anti-CCP and IgM RF were measured in harvested blood samples. Laboratory results from the patients with low radiographic knee OA (grade I and II) were compared to those in high grade patients (grade III and IV). The mean serum level of ESR in low and high grade groups was 12.85±18.65 and 13.65±15.25 respectively (p = 0.77(. As for the anti-CCP, the values of 13.87±43.75 and 23.42±58.87 were obtained for low and high grades respectively (p = 0.26). The differences between the positivity of RF (p = 0.51) and CRP (p = 0.56) in both groups was also not statistically significant. But inflammation score was significantly higher in high grade group than low grade group (p = 0.03). We conclude that although the differences weren't remarkable but severity of inflammation in higher radiographic grades should be taken into consideration of OA's progression.