The involvement of inflammatory components in the pathophysiology of low back pain (LBP) is poorly understood. It has been suggested that spinal manipulative therapy (SMT) may exert anti-inflammatory effects.
The purpose of this study was to determine the involvement of inflammation-associated chemokines (CC series) in the pathogenesis of nonspecific LBP and to evaluate the effect of SMT on that process.
Patients presenting with nonradicular, nonspecific LBP (minimum pain score 3 on 10-point visual analog scale) were recruited according to stringent inclusion criteria. They were evaluated for appropriateness to treat using a high velocity low amplitude manipulative thrust in the lumbar-lumbosacral region. Blood samples were obtained at baseline and following the administration of a series of 6 high velocity low amplitude manipulative thrusts on alternate days over the period of 2 weeks. The in vitro levels of CC chemokine ligands (CCL2, CCL3, and CCL4) production and plasma levels of an inflammatory biomarker, soluble E-selectin (sE-selectin), were determined at baseline and at the termination of treatments 2 weeks later.
Compared with asymptomatic controls baseline production of all chemokines was significantly elevated in acute ( P=0.004 to <0.0001), and that of CCL2 and CCL4 in chronic LBP patients ( P<0.0001). Furthermore, CCL4 production was significantly higher ( P<0.0001) in the acute versus chronic LBP group. sE-selectin levels were significantly higher ( P=0.003) in chronic but not in acute LBP patients. Following SMT, patient-reported outcomes showed significant ( P<0.0001) improvements in visual analog scale and Oswestry Disability Index scores. This was accompanied by a significant decline in CCL3 production ( P<0.0001) in both groups of patients. Change scores for CCL4 production differed significantly ( P<0.0001) only for the acute LBP cohort, and no effect on the production of CCL2 or plasma sE-selectin levels was noted in either group.