Expression of miRNA-124a in CD4 Cells Reflects Response to a Multidisciplinary Treatment Program in Patients With Chronic Low Back Pain

STUDY DESIGN.Prospective evaluation of miRNA expression in patients with chronic low back pain (CLBP). OBJECTIVE.To evaluate whether pain and T cell related miRNAs are differentially expressed in CLBP when compared to healthy volunteers and whether these miRNAs may distinguish between responders and non-responders to a multidisciplinary treatment program. SUMMARY OF BACKGROUND DATA.CLBP is a common health problem worldwide. Multidisciplinary pain treatment programs have been proven as effective treatment option. MicroRNAs (miRNAs) are known to be important mediators of gene regulation in various processes, including pathophysiology of pain. The expression of miRNAs in CLBP and changes due to multidisciplinary treatment programs are still unknown. METHODS.34 patients with CLBP were enrolled (46.5 ± 12.7 years). CLBP was defined as low back pain with an average intensity of NRS≥ 3 during the last 4 weeks, persisting longer than six months, and not attributable to a recognized specific pathological condition. Expression of pain and T cell related miRNAs in human CD4 cells were determined using TaqMan assays and RealTime PCR. MiRNA expression in patients with CLBP was compared to the expression in healthy volunteers before a multidisciplinary treatment program started. The multidisciplinary outpatient program (four weeks, five days a week, eight hours per day) is a clinically established outpatient program and comprises medical (examination, education), physical (exercise), work-related and psychological therapy components. After the program, differentially expressed miRNAs in CLBP (before treatment) were analyzed once more. Expression of these miRNAs in patients who respond to the treatment (n = 14) was compared to those who did not respond (n = 20). Response to therapy was defined as reduction of pain of ≥ 50% (NRS) from baseline. RESULTS.MiRNA-124a (patients0.79 ± 0.63 vs. healthy volunteers0.30 ± 0.16; p