Analysis of IL-6 marker in synovial fluid of the knee joint in patients with osteoarthritis and rheumatoid arthritis before and after platelet-rich plasma administration

Platelet-rich plasma (PRP) has emerged as a treatment for osteoarthritis (OA) and rheumatoid arthritis (RA). The aim of the current study is to assess the effect of PRP injection and its influence on interleukin-6 (IL-6) in the synovial fluid of the knee joint in OA and RA patients.

Clinico-radiologically diagnosed case of OA and RA of 30 each was included during the study period of 2 years. 10 ml of patient blood collected and PRP was prepared by differential centrifugation method, and this freshly prepared PRP was injected to the affected knee joint slowly. IL-6 levels assessed in synovial fluid at pre-PRP injection and 1st, 3rd and 6th month post-PRP Injection. Pain was measured using Visual Analog Scale.

The mean age of the cases was 58.5 years for OA and 47.2 years for RA. Females were predominantly compared to males. Majority were Kellegren Lawrence radiological grade 3 in 15 (50%) cases, following grade 2 in 8 (26.67%) cases, grade 4 in 6(20%) cases and grade 1 in 1(3.33%) case. Mean IL-6 in OA cases was 89.5±24.5 pg/ml at pre PRP, and 66.48±23.1 pg/ml at post PRP (p<0.001, paired t-test). Mean IL-6 in RA was 97.5±18.9 pg/ml at pre-PRP injection, and 89.6±17.9 at post PRP (p<0.001, paired t-test). In OA cases, paired t-test between the mean pain scores (VAS) at follow-up depicts that the mean difference and standard error of difference between 6-month follow-up and one-month follow-up was -1.23 ± 0.20 statistically significant differences (95%CI: -1.71 to -0.73). In RA cases, paired t-test between the mean pain scores (VAS) at followup depicts that the mean difference and standard error of difference between 6-month follow-up and one-month follow-up was -1.38 ± 0.19 statistically significant differences (95% CI: -1.69 to -0.75). There was a positive correlation between levels of IL-6 and pain score (r=0.309, p=0.004).

Study shows that anti-Inflammatory role of PRP, which was evidenced by the statistically significant difference in the IL-6 levels at follow-up. It may be beneficial to halt the progress in arthritic joints. This study successfully established an anti-inflammatory role of PRP in joint pathology by influencing the IL-6 levels.