The COL1A1 gene encodes the α1 chain of type I collagen, and the data reported so far demonstrate that its polymorphic variants may affect biomechanical properties of bones, muscles, and tendons, and contribute to musculoskeletal disorders. Given, however, limited research on these variants in tendon pathology, we analyzed the impact of COL1A1 polymorphisms on the tendinopathy phenotype and the effectiveness of platelet-rich plasma (PRP) treatment for tennis elbow. Pain perception and therapy outcomes were analyzed from baseline, i.e., before PRP injection to two years post-PRP injection in a cohort of 107 patients. The study focused on seven COL1A1 variants: rs2249492 (C/T), rs2586488 (A/G), rs2075558 (A/C), rs2253369 (C/T), rs35231764 (A/G), rs1800012 (C/A), and rs9898186 (C/T). We demonstrated that carriers of the TT/CT (rs2249492), AA/AC (rs1800012), and TT/CT (rs9898186) genotypes reported pain related to injury more frequently than subjects with other COL1A1 variants, also in the context of performing specific activities and other pain characteristics. These polymorphisms did not significantly influence therapy effectiveness, although rs35231764 showed a moderate effect. In conclusion, the T (rs2249492), A (rs1800012), and T (rs9898186) alleles of COL1A1 gene are risk factors for pain perception in tennis elbow patients, but do not appear to substantially impact PRP treatment outcomes.
Keywords: COL1A1; collagen; genetic polymorphism; platelet-rich plasma; tendinopathy; tennis elbow.