Why PRP works only on certain patients with tennis elbow? Is PDGFB gene a key for PRP therapy effectiveness? A prospective cohort study

Abstract

Background There is variability in individual response to platelet-rich plasma (PRP) therapy in tennis elbow treatment. Genetic variation, especially within genes encoding growth factors may influence the observed inter-individual differences. The purpose of this study was to identify polymorphic variants of the platelet-derived growth factor beta polypeptide gene (PDGFB) that determine an improved individual response to PRP therapy in tennis elbow patients. Methods This prospective cohort study was designed in accordance with STROBE and MIBO guidelines. A cohort of 107 patients (132 elbows, 25 bilateral) was studied, including 65 females (77 elbows) and 42 males (55 elbows), aged 24–64 years (median 46.00 ± 5.50), with lateral elbow tendinopathy treated with autologous PRP injection. The effectiveness of PRP therapy was recorded in all subjects at 2, 4, 8, 12, 24 and 52 weeks after PRP injection using the Visual Analog Scale (VAS), quick version of Disabilities of the Arm, Shoulder and Hand score (QDASH) and Patient-Rated Tennis Elbow Evaluation (PRTEE). In order to determine the PDGFB variants with the best response to PRP therapy, patient reported outcome measures were compared between individual genotypes within studied polymorphic variants (rs2285099, rs2285097, rs2247128, rs5757572, rs1800817 and rs7289325). The influence of single nucleotide polymorphisms on blood and PRP parameters, including the concentration of PDGF-AB and PDGF-BB proteins was also analyzed. Results Our analysis identified genetic variants of the PDGFB gene that lead to a better response to PRP therapy. The TT (rs2285099) and CC (rs2285097) homozygotes had higher concentration of platelets in whole blood than carriers of other genotypes (p = 0.018) and showed significantly (p < 0.05) lower values of VAS (weeks 2–12), QDASH and PRTEE (weeks 2–24). The rs2285099 and rs2285097 variants formed strong haplotype block (r2 = 98, D’=100). The AA homozygotes (rs2247128) had significantly lower values of VAS (weeks 4–52), QDASH and PRTEE (weeks 8, 12). Conclusions PDGFB gene’s polymorphisms increase the effectiveness of PRP therapy in tennis elbow treatment. Genotyping two polymorphisms of the PDGFB gene, namely rs2285099 (or rs2285097) and rs2247128 may be a helpful diagnostic tool while assessing patients for PRP therapy and modifying the therapy to improve its effectiveness.

What Role Does PDGFA Gene Polymorphisms Play in Treating Tennis Elbow with PRP? A Prospective Cohort Study

“…In our previous work, we showed that specific genotypes of the PDGFB gene, namely TT (rs2285099), CC (rs2285097), and AA (rs2247128) were associated with a significantly higher effectiveness of PRP therapy. during almost the entire one-year follow-up period [ 13 ]. These data, together with the results of the present study, suggest that the body’s response to the PRP therapy may be the result of the interaction of multiple gene variants (multi-gene inheritance model).…”

“…The study population was the same as in our previous work [ 13 ]. Patients were recruited for the study between November 2018 and November 2019.…”

“…Approximately 0.5 mL was left for protein analyses. The exact procedures of PRP separation and injection were described previously [ 13 ].…”

“…As in our previous work [ 13 ], the complete blood count and the platelet parameters in whole blood and fresh PRP were determined. The PDGF-AB protein concentration was measured in PRP using the Human DuoSet ELISA kit (R&D Systems Inc., Minneapolis, MN, USA).…”

“…The procedure used for DNA isolation and genotyping was the same as in our previous study [ 13 ]. The MasterPure genomic DNA purification kit (Epicenter Technologies, Madison, WI, USA) was used for DNA isolation.…”