To analyze the presence of inflammatory cells in the synovial fluid (SF) of subjects with osteoarthritis (OA) and correlate them with the concentration of sulfated glycosaminoglycan (GAG).
The degree of chondral injury from 20 subjects (17 men, 3 women, mean age 48.06 +/- 14.35 yrs) was evaluated macroscopically by means of arthroscopy and graded according to the International Cartilage Repair Society classification. All subjects presented anterior cruciate ligament (ACL) injuries, associated or not to menisci injuries. SF was aspirated and centrifuged. Sulfated GAG concentration was quantified by dimethylene blue staining. Manual morphometry was used to determine the inflammatory cell count (mononuclear and polymorphonuclear) by optical microscopy, after staining with May-Grünwald-Giemsa. The time of injury and degree of chondral injury were considered, and correlations among the variables were obtained by Spearman nonparametric correlation test.
There was no significant correlation between the amount of mononuclear cells and the GAG concentration. There was a significant positive correlation between the polymorphonuclear cells and the GAG concentration, and a significant negative correlation between the degree of chondral injury and the GAG concentration.
Polymorphonuclear cells may be either a cause or an effect in the metabolic and biochemical processes occurring in chondral injuries. The correlations support the hypothesis that inflammatory cells have a significant role in the progression and chronicity of chondral injury in secondary OA.