Long Term Effects of Hyaluronate Viscosupplementation on Th17 and Activated CD4+ T Lymphocytes Blood Expression in Patients with Hip or Knee Osteoarthritis

Background: Osteoarthritis (OA) is a chronic disease associated with joint destruction that has long been regarded in the past as a “no inflammatory” disease. Aim of our study was to measure in the long term characteristics of T lymphocytes CD4+ Th1 Th2 and Th17 in peripheral blood of patients with hip or knee OA treated with viscosupplementation. Methods: Patients with early primary knee or hip OA (ACR Criteria) who completed the 3 months study about the peripheral T lymphocytes concentration as described from our study group(Osteoarthritis Cartilage. 2015 Jan;23(1):88-93) entered this long-term extension. After 6 months from the last observation (i.e. 9 months check-point from baseline), a new flow-cytometry from blood samples to assess T cells subpopulations (CD3, CD4, CD8, CCR6, CD38, CxCR3, and HLA DR) was performed. Lequesne index was scored and compared to data at baseline and at the end of the original study. Results: 35 patients treated were recruited (24 knee OA, 11hip OA). Data of 15 subjects with OA in the control untreated group were collected too. In the treated group, Th 17, activated CD4 T cells levels, Th2, Th1were similar to those observed after 3 months from viscosupplementation course (p=0.07), persistently higher than in control group (p=0.01). Lequesne index was also significantly higher between treated and control groups (p=0.01). Conclusion: Our results seem to show that HA injections maintain low levels of activated T cells in patients with hip or knee OA. Alongside also the severity indices show a similar trend.