Neutrophil-to-Monocyte-Plus-Lymphocyte Ratio as a Potential Marker for Discriminating Pulmonary Tuberculosis From Nontuberculosis Infectious Lung Diseases

You La Jeon, MD, PhD; Woo-In Lee, MD, PhD; So Young Kang, MD, PhD; Myeong Hee Kim, MD, PhD


Lab Med. 2019;50(3):286-291. 

In This Article

Abstract and Introduction


Objective: To determine whether NMLR has more statistical strength than NLR in discriminating TB from non-TB infectious lung diseases.

Methods: Among patients who underwent 3 or more TB culture tests with molecular study between January 2016 and December 2017, 110 patients with TB, and 159 patients diagnosed with non-TB infectious lung diseases were enrolled. The original complete blood count (CBC) parameters and modified CBC indices, including NLR and NMLR, were analyzed.

Results: The NLR and NMLR were significantly lower in TB patients than in patients with other infectious lung diseases. However, the area under the curve (AUC) for NMLR (0.90; 95% confidence interval [CI], 0.86–0.93) was significantly greater than that for NLR (0.88 [0.84–0.92]).

Conclusions: The neutrophil-to-monocyte-plus-lymphocyte ratio (NMLR) can be used as a new index that is more powerful than neutrophil-to-lymphocyte ratio (NLR) in discriminating tuberculosis (TB) from non-TB infectious lung diseases.

NMLR had more statistical strength than NLR in discriminating TB from non-TB infectious lung diseases.


Complete blood count (CBC) parameters such as neutrophils, lymphocytes, and platelets, as well as modified CBC indices representing ratios, have been suggested as diagnostic markers for many infectious or inflammatory diseases and as prognostic markers for malignant diseases.[1–4] In pulmonary tuberculosis (TB) infection, these CBC parameters and modified indices have been assessed as diagnostic markers. Patients with TB tend to have increased neutrophil and monocyte counts and decreased lymphocyte counts, compared with healthy subject individuals.[5–7] Moreover, the monocyte-to-lymphocyte ratio (MLR) was suggested as a predictive marker of active TB in a report comparing healthy subjects to patients with TB.[8]

Recently, the neutrophil-to-lymphocyte ratio (NLR) has been reported as a useful marker for differential diagnosis between TB and bacterial pneumonia or sarcoidosis.[9,10] Also, the platelet-to-lymphocyte ratio (PLR) was also introduced as a potential marker to identify TB infection in patients with chronic obstructive pulmonary disease (COPD).[11] However, research on the role of CBC parameters or modified indices in discriminating TB from non-TB infectious lung diseases is lacking; further studies are needed.

The aim of this study was to analyze the clinical efficacy of the original CBC parameters and the modified CBC indices, such as MLR, NLR, and PLR, with additional CBC parameters in the differential diagnosis of TB from non-TB infectious lung diseases. The neutrophil-to-monocyte-plus-lymphocyte ratio (NMLR), defined as the neutrophil count/(monocyte count + lymphocyte count), was the first marker we had developed for this study (considering the CBC parameters of patients with TB), compared with those in patients with non-TB infectious lung diseases. This study evaluated the NMLR as a diagnostic marker to differentiate TB from other infectious diseases in comparison with other parameters, especially the NLR.