In 1994, Research led by P.C. Brennan, et. al., have delved into the lymphocyte profiles of patients enrolled in a clinical trial focusing on manipulative therapies for chronic low back pain (LBP) with mechanical origins. The study, conducted at a chiropractic teaching clinic in suburban Chicago, aims to contribute valuable insights into the immune system’s role in chronic LBP.

The randomized controlled trial involved baseline measures taken at the initial visit, followed by 11 scheduled treatments within 14 days. Patients received one of three interventions: a high-force, high-velocity, low-amplitude manipulation; a low-force, high-velocity, low-amplitude procedure; or a series of educational lectures on lower back pain. Posttreatment measures were collected at the final session, with follow-up measures obtained two weeks later.

The participants, totaling 201 patients, were over 18 years old, with LBP lasting more than 50 days and pain elicited during palpation over facet joints from spinal levels L1 to S1. Exclusion criteria included neurological signs, systemic diseases affecting the musculoskeletal system, contraindications to spinal manipulation, and medication use for LBP symptoms.

Outcome measures focused on the absolute numbers and percentages of B-lymphocytes, T-lymphocytes, T-Helper (TH), T-Suppressor (TS), and Natural Killer (NK) lymphocytes. Blood samples were collected simultaneously with primary outcome measures, and flow cytometry was employed for quantification.

Results indicated that at baseline, there were no significant differences in lymphocyte profiles among the three intervention groups. All baseline values fell within reported reference ranges for normal adults, except for the percentage of NK cells, which was below the published minimum critical value. Notably, 35 patients dropped out before follow-up, and technical issues led to data loss, resulting in 148 cases analyzed for B cells, 146 for TH, TS, and NK cells, and 138 for cells carrying both NK and TS markers.

The researchers conducted a repeated measures analysis of variance to assess treatment effects over time. Interaction tests revealed that TH cells, total T cell percent, and absolute total T cells showed statistical significance. However, no significant differences were observed for B cells, TS cells, or NK cells in terms of either percent or absolute counts.

In conclusion, this study represents the first examination of lymphocyte profiles in patients with diagnosed chronic LBP. The lower percentage of NK cells in these patients aligns with previous findings regarding musculoskeletal problems. However, manipulative therapy did not demonstrate a clinically significant effect on lymphocyte profiles. Further research may illuminate the complex relationship between immune function and chronic LBP.

Reference: Brennan, P. C., Graham, M. A., Triano, J. J., Hondras, M. A., & Anderson, R. J. (1994). Lymphocyte profiles in patients with chronic low back pain enrolled in a clinical trial. Journal of Manipulative and Physiological Therapeutics, 17(4), 219-227.