Pretreatment neutrophil-to-lymphocyte ratio in peripheral blood was associated with pulmonary tuberculosis retreatment.

INTRODUCTION

The neutrophil-to-lymphocyte ratio (NLR) is a readily available biomarker associated with recurrence and survival in various diseases. The objective of this study was to investigate the relationship between NLR and pulmonary tuberculosis (PTB) retreatment.

MATERIAL AND METHODS

This was a case-control study that included 306 newly diagnosed cases of PTB in the clinical database of the Infectious Hospital of Wuxi from December 2009 to December 2011. Of the 306 patients, a total of 68 cases were followed up with TB retreatment. The remaining 238 PTB patients who completed anti-TB treatment and were cured without retreatment were selected as controls.

RESULTS

According to the ROC curve, the best cut-off value of NLR was 2.53, with a sensitivity of 70.6% and a specificity of 45.4%. The NLR ≥ 2.53 before anti-TB treatment was associated with PTB retreatment (OR = 1.994, 95% CI: 1.116-3.564; adjusted OR (AOR) = 2.409, 95% CI: 1.212-4.788). The retreatment rates with NLR ≥ 2.53 and NLR < 2.53 were 27.1% and 15.5%, respectively, with a significant difference (log-rank test; = 0.010). Additionally, cavitation on chest X-ray (OR = 2.922, 95% CI: 1.654-5.411; AOR = 2.482, 95% CI: 1.230-5.007), history of smoking (OR = 2.202, 95% CI: 1.158-3.493; AOR = 2.321, 95% CI: 1.135-4.745) and age ≥ 60 (OR = 3.828, 95% CI: 1.626-9.015; AOR = 2.931, 95% CI: 1.122-7.653) were also associated with PTB retreatment.

CONCLUSIONS

NLR ≥ 2.53 is predictive of PTB retreatment. Otherwise, initial cavitation on chest X-ray, history of smoking, and age of ≥ 60 are also risk factors for PTB retreatment.