Allogeneic Platelet-rich Plasma for Knee Osteoarthritis in Patients with Primary Immune Thrombocytopenia: A Randomized Clinical Trial

The treatment of painful KOA in adult patients with ITP has not been well studied yet. We conducted a prospective, double-blind, randomized, placebo-controlled trial to evaluate the efficacy of intra-articular allogeneic PRP injections on symptoms and joint structure in patients with KOA and ITP. 80 participants were randomly allocated in a 1:1 ratio to allogeneic PRP group or saline group. The primary outcome was the WOMAC total score at 12 months post-injection. The number of patients in each group who achieved MCID of primary outcome showed a statistically significant difference only at 3-month (27/39 vs 5/39, P = .001) and 6-month (15/39 vs 3/38, P = .032). The difference in WOMAC total score exceeded the MCID only at 3-month (mean difference of -15.1 [95% CI -20.7 to -9.5], P < .001). Results suggest that allogeneic PRP was superior to placebo only with respect to symptoms at 3-month of follow-up.