Potential blood markers as screening tools for subjects with low back pain: an age- and gender-matched cross-sectional analysis.

Introduction: Mechanical and inflammatory factors were suggested as the causes of spine degeneration and low back pain (LBP). Previous studies partly reported the association of LBP with inflammation. However, none of them compared patients with LBP and asymptomatic subjects in terms of complete blood count and inflammatory markers in detail. We aimed to analyze the association of serum white blood cell (WBC) count, C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) with chronic LBP by comparing the patients with chronic LBP and age- and gender-matched asymptomatic subjects. Methods: Lumbar intervertebral disc degeneration and vertebral end-plates were evaluated using Pfirrmann grading and Modic classification on lumbar spine magnetic resonance imagings, respectively. Serum WBC counts, CRP levels, and ESRs were recorded from chart reviews. Results: We included 147 patients with chronic LBP and 101 asymptomatic subjects. Patients with chronic LBP had significantly higher serum neutrophil, monocyte, and basophil counts, higher neutrophil-to-lymphocyte ratio, higher ESR and lower serum CRP levels compared to the asymptomatic subjects. Serum monocyte and basophil cell counts and ESR were the most remarkable predictive factors for chronic LBP, severe IVDD, and Modic changes. Higher serum monocyte and basophil cell counts and higher serum ESR above cut-off values of 0.42 x 10^3/uL, 0.025 x 10^3/uL, and 3.5 mm/hour could be used as screening tool for subjects with persistent LBP in primary care. Discussion: Higher serum monocyte and basophil counts and serum ESR above new cut-off values should be alarming to obtain early spinal imaging and to prevent chronicity in patients with LBP.