The Association Between Three MMP3 Gene Polymorphisms and the Efficacy of Platelet-Rich Plasma Therapy in the Treatment of Lateral Elbow Tendinopathy-A Prospective Cohort Study.

Matrix metalloproteinases (MMPs) are proteolytic enzymes involved in connective tissue remodeling. Matrix metalloproteinase 3 (MMP3) belongs to the MMP family and is associated with the pathogenesis of tendinopathy. Moreover, MMP3 gene polymorphisms have been associated with the risk of tendinopathy development. The goal of this study was to investigate whether this gene polymorphisms could also affect the effectiveness of platelet-rich plasma (PRP) tendinopathy treatment. 107 patients (132 elbows) with lateral elbow tendinopathy underwent PRP injection and were followed for two years at specific follow-up weeks (2, 4, 8, 12, 24, 52, 104). The effectiveness of the therapy was assessed based on patient-reported outcome measures (PROMs) values, specifically visual analogue scale (VAS), quick version of the disabilities of the arm, shoulder and hand (QDASH), patient-rated tennis elbow evaluation (PRTEE), and the achievement of minimal clinically important difference (MCID). Three MMP3 single nucleotide polymorphisms (SNPs) (rs520540, rs591058, rs679620) were genotyped using the TaqMan method. All studied polymorphisms were found to present strong linkage disequilibrium and were associated with the effectiveness of therapy on the VAS scale (week 4) and PRTEE (week 104), as well as with MCID achievement (PRTEE week 4); however, these were not strong associations. The studied SNPs also showed an association with the frequency of hand pain before treatment. MMP3 gene polymorphisms are associated with pain experienced before PRP therapy, but do not show a clear association with treatment effectiveness.