Objective: To analyse the correlations between the levels of Tumor Necrosis Factor α, Matrix Metalloproteinase 8, Interleukin 6 and the presence of cartilage lesions in the knee.
Methods: We studied 79 individuals divided in three groups – a group with cartilage lesions, a group with meniscal lesions and a control group. All patients underwent arthroscopic surgical interventions – either diagnostic or therapeutic. Venous blood samples and synovial fluid samples were obtained and we determined the levels of TNF-α, MMP-8 and IL-6 respectively. All study participants filled out the International Knee Documentation Committee (IKDC) Subjective Knee Evaluation Score questionnaire, based on which the IKDC score was calculated.
Results: we found higher levels of MMP-8 in both serum and synovial fluid for groups 1 and 2 compared to the control group, but no correlation between the serum and synovial fluid levels of MMP-8. The serum MMP-8 levels showed a significant negative correlation with the highest level of activity without pain and significant giving way. The synovial MMP-8 could be correlated to the IKDC score. Serum levels and synovial levels of TNF-α were in strong correlation. We found no association between serum and/or synovial TNF-α and MMP-8 levels.
Conclusions: We found that synovial MMP-8 concentrations showed a reverse correlation with the IKDC scores (an activity-based score) – thus MMP-8 might be a diagnostic and prognostic marker in knee osteoarthritis.