Neutrophil–lymphocyte ratio as a potential marker for differential diagnosis between spinal tuberculosis and pyogenic spinal infection

Objective Distinguishing spinal tuberculosis and pyogenic spinal infection is extremely important. The neutrophil–lymphocyte ratio (NLR), a simple indicator, has been shown to be a novel inflammatory marker. The objective of our study was to determine whether the NLR could be a potential indicator for discriminating spinal tuberculosis (STB) from pyogenic spinal infection (PSI). Methods We compared the clinical and laboratory characteristics of 146 patients diagnosed with STB and 60 participants with PSI from the First Affiliated Hospital of Nanjing Medical University. The NLR's diagnostic ability for differential diagnosis was assessed and compared to other hematological indicators, including the platelet–lymphocyte ratio (PLR). Results The NLR in STB patients was considerably lower than that in PSI patients [3.85 (2.70–5.71) vs. 10.82 (6.79–17.62), P < 0.001]. An NLR of 6.742 was proposed as an optimal cutoff value for distinguishing patients with STB from those with PSI (sensitivity 78.33%, specificity 83.56%). However, the NLR's area under the curve [0.87, 95% confidence interval (CI) 0.81–0.92] was considerably higher than that of the PLR (0.73, 95% CI 0.65–0.80; P < 0.0001). Conclusion NLR levels could be a valuable laboratory diagnostic for distinguishing patients with STB from those who have PSI.