# 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

## TL;DR

This study explores how genetic variations in the MMP3 gene affect the effectiveness of platelet-rich plasma therapy for elbow tendinopathy.

## Contribution

The study is the first to investigate the association between MMP3 gene polymorphisms and PRP therapy outcomes in lateral elbow tendinopathy.

## Key findings

- MMP3 SNPs were associated with pre-treatment hand pain frequency.
- SNPs showed weak associations with short- and long-term pain and function outcomes.
- No strong evidence was found linking MMP3 polymorphisms to PRP treatment effectiveness.

## Abstract

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.