Acupuncture and Celecoxib for Chronic Knee Pain: Genetic Factors May Influence Response

The mechanisms underlying individual variability in acupuncture analgesia among patients with chronic pain remain unclear. This randomized controlled trial investigated the core mechanisms of differential responses to acupuncture from genetic, neuroimaging, and transcriptomic perspectives in patients with chronic pain due to knee osteoarthritis (KOA). A total of 180 KOA chronic knee pain patients were randomly assigned to verum acupuncture (VA), sham acupuncture (SA), celecoxib (SC), placebo (PB), or waiting list (WL) groups (36 each). Over 2 weeks, VA/SA received 10 sessions, SC/PB oral medication for 14 days, and WL no intervention. Baseline 3.0T MRI 3D-T1 scans and genotyping (GABRB3 rs4906902, OPRM1 rs1799971, COMT rs4680, BDNF rs6265) were performed. Efficacy was assessed via VAS and WOMAC; responders/non-responders were defined by minimally clinically important difference. Chi-square test, logistic regression, voxel-based morphometry (VBM), and Allen Human Brain Atlas-based partial least squares regression were used. No significant difference in primary outcomes was observed between VA and SA, so they were combined as the acupuncture group (AG) to enhance statistical power. Only AG had a significant association between GABRB3 rs4906902 AG/GG genotype and acupuncture response (p < 0.05); other loci showed no correlation. AG/GG carriers in AG had lower gray matter volume in caudate head, putamen, and ventral striatum, with higher GABRB3 expression in these regions. Genetic polymorphisms at GABRB3 rs4906902 could influence the analgesic effect of acupuncture treatment in patients with KOA chronic knee pain, with AG/GG genotype carriers exhibiting superior analgesic effects. This finding may be associated with pain-modulating brain regions' gray matter volume reduction and upregulation of GABRB3 gene expression.