Impact of Vascular Endothelial Growth Factor Concentration on the Short-term Efficacy of Platelet-Rich Plasma (PRP) Therapy for Knee Osteoarthritis

Introduction This study investigates the association between vascular endothelial growth factor (VEGF) levels and platelet-rich plasma (PRP) treatment outcomes, as well as the role of other cytokines in symptom improvement.Methods Thirty-nine patients with knee osteoarthritis (KOA) who underwent PRP therapy were analyzed. Cytokine and growth factor levels in PRP were measured, and clinical outcomes were assessed using the visual analog scale (VAS) and the Knee Injury and Osteoarthritis Outcome Score (KOOS) before and 1 month after a single intra-articular PRP injection. Correlations between cytokine levels and clinical improvements were evaluated.Results Age correlated positively with C-X-C motif chemokine ligand 9 (CXCL9) (r = 0.50, p < 0.001). Body mass index (BMI) correlated negatively with interleukin-10 (IL-10) and positively with interleukin-18 (IL-18). Elevated IL-18 levels correlated with worse KOOS-Activities of Daily Living (ADL) improvements (r = -0.410, P = 0.01), linking obesity, inflammation, and reduced PRP efficacy. While VEGF showed no association with patient background, higher VEGF levels correlated with poorer VAS score improvements (r = -0.381, P = 0.017), suggesting reduced PRP efficacy. A VEGF cut-off of 120 pg/ml identified non-responders with 82.6% sensitivity, 56.2% specificity, and an area under the curve (AUC) of 0.71. Among patients with VEGF >= 120 pg/ml, the response rate was 26.9%, while those with VEGF <120 pg/ml had 75%.Conclusions Higher VEGF concentrations in PRP were associated with reduced short-term clinical efficacy in patients with knee osteoarthritis. VEGF may serve as a predictive biomarker for PRP treatment response.