IGF‐1 levels, genetic polymorphisms, and intrameniscal platelet‐rich plasma are associated with clinical response in a caucasian cohort with mild‐to‐moderate knee osteoarthritis

Purpose This study aimed to evaluate the influence of patient clinical and demographic characteristics, platelet‐rich plasma composition, and genetic factors on the response to PRP therapy in patients with KOA. Methods Patients of both sexes over 18 years old diagnosed with mild/moderate KOA (Ahlbäck grade I–II) received three intra‐articular injections of 8 mL of leucocyte‐ and erythrocyte‐free PRP with a moderate platelet concentration. In cases of degenerative meniscal lesions, additional intrameniscal injections were performed. Patients did not receive any other medical treatment or physiotherapy. Clinical outcomes were assessed using the Knee Injury and Osteoarthritis Outcome Score (KOOS) at baseline and at 6 months. Patient‐related variables, PRP composition, and genetic polymorphisms were analyzed. Associations with treatment response were evaluated using chi‐squared tests, and a prognostic model was developed using binary logistic regression. Results A total of 300 patients were included. The mean age was 55.5 ± 13.6 years with a median body mass index (BMI) of 26.7 ± 4.0 and 110 women (36.7%). At 6 months, 207 patients (69.0%) were responders showing minimal clinically important improvement. The application of intrameniscal PRP in patients with associated degenerative meniscus injury showed a significant association with the response to PRP ( p = 0.011). While platelet concentration was not associated with a greater response ( p = 0.938), insulin‐growth factor 1 (IGF‐1) concentration was ( p = 0.033). Twelve genetic polymorphisms showed a significant association, including both effector molecules and cell receptors, with particular relevance to the IGF family. Conclusion Intrameniscal PRP application in meniscal injuries associated with KOA, the presence of IGF‐1 in PRP composition, and polymorphisms within the IGF family and genes related to growth factors, cell receptors, and inflammatory pathways were associated with treatment outcomes. These variables enabled the development of a preliminary multivariable model to estimate the probability of response to PRP. Level of Evidence Level IV.