Description
Background: Platelet-rich plasma (PRP) is increasingly used for the injective treatment of knee osteoarthritis (OA). However, the role of leukocytes contained in PRP is controversial, with some preclinical studies suggesting detrimental effects while others emphasizing their contribution in secreting bioactive molecules.
Purpose: To compare the safety and effectiveness of fresh leukocyte-rich PRP (LR-PRP) and fresh leukocyte-poor PRP (LP-PRP) for the treatment of knee OA.
Methods: This double-blinded randomized controlled trial (RCT) included 132 patients affected by Kellgren-Lawrence I-III knee OA, who were randomized in a 3-injection cycle of either LR-PRP or LP-PRP. Patients were prospectively assessed at baseline, 2, 6, and 12 months with the International Knee Documentation Committee (IKDC) subjective score, the Knee injury and Osteoarthritis Outcome Score (KOOS) scales, the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) score, the pain visual analogue scale (VAS), the EuroQol VAS (EQ-VAS), the EQ-5D and the Tegner sores. Objective evaluations were the IKDC objective score, active/passive range of movement and circumference of treated and contralateral knees. Patient judgment on the treatment was recorded, as well as adverse reactions and failures.
Results: An overall improvement in the subjective and objective clinical scores was documented with no differences between the two groups, except for the IKDC subjective improvement at 2 months, which was greater for LR-PRP (14.8±14.8 vs 8.6±13.3, p=0.046). The IKDC subjective score improved from the baseline value of 42.5±17.6 to 55.6±21.4 at 12 months for the LR-PRP group (p<0.0005) and from 45.7±16.4 to 55.3±20.4 for the LP-PRP group (p=0.001). No differences in terms of patient treatment judgement were observed at all follow-ups. No severe adverse events related to the treatment were reported, while some mild adverse events related to the treatment were observed: 16 in LR-PRP and 17 in LP-PRP; 5 patients failed in the LR-PRP group, 2 in the LP-PRP group.
Conclusion: This double-blind RCT demonstrated that leukocytes do not affect safety and efficacy of intra-articular PRP injections for the treatment of patients with knee OA. LR-PRP and LP-PRP demonstrated comparable clinical outcomes at all follow-up evaluations, without showing differences in terms of subjective and objective scores, as well as adverse events and treatment failures.
