Abstract:

Objective To investigate the changes of neutrophil-to-lymphocyte ratio (NLR) in peripheral blood of secondary pulmonary infection patients with type 2 diabetes mellitus (T2DM) complicated with pulmonary tuberculosis (PTB). Methods A retrospective study was conducted in 951 T2DM patients complicated with PTB, who were hospitalized for the first time in the Tuberculosis Department of Guangzhou Chest Hospital from January 2013 to January 2018. They were newly treated and the TB detection is positive, the clinical data including age, gender, clinical symptoms, diabetes history, glycosylated hemoglobin A1c (HbA1c), peripheral blood white blood cell (WBC) count, neutrophil count, lymphocyte count and anti-infective treatment effect were analyzed. All the patients were divided into infection group and non-infection group according to whether they had secondary pulmonary infection when admission; according to whether the peripheral blood lymphocyte count was ≥0.8×10⁹/L when admission, they were divided into normal group and low lymphocyte count group. The correlation between NLR and secondary lung infections in the study subjects was analyzed. Results Of the patients, 524 suffered secondary lung infection (55.10%); the lesion mainly involved 5-6 lung fields in the infected group (60.5%, 317/524), which was significantly higher than that in the non-infected group (41.0%, 175/427) (χ²=42.587, P=0.000). The NLR level of the infected group (M(Q₁,Q₃)) was 6.79 (5.10, 9.70), which was significantly higher than that of the non-infected group (3.01 (2.27, 3.55)) (U=16 545.00, P=0.000). The NLR levels (M(Q₁,Q₃)) of patients with low peripheral blood lymphocyte counts in the infected and non-infected groups were 12.09 (8.67, 16.05) and 4.26 (3.71, 6.39), respectively, both significantly higher than those of patients whose peripheral blood lymphocytes counts were normal (5.90 (4.71, 7.55), U=5964.00, P=0.000 and 2.97 (2.25, 3.80), U=1695.50, P=0.000, respectively). The neutrophil count (M(Q₁,Q₃)) of patients with low peripheral blood lymphocyte counts were 6.42 (5.01, 9.07)×10⁹/L and 3.13 (1.88, 3.51)×10⁹/L, in the two groups, which were significantly lower than those of patients with normal peripheral blood lymphocyte count (7.90 (6.72, 9.27)×10⁹/L, U=18697.00, P=0.000 and 4.57 (3.70, 5.40)×10⁹/L, U=1257.00, P=0.000, respectively). Conclusion The level of NLR in the secondary pulmonary infection in T2DM patients complicated with PTB was significantly increased, and patients with low peripheral blood lymphocyte counts were prone to secondary lung infection.

Key words: Tuberculosis,pulmonary, Diabetes Mellitus,Type 2, Infection, Neutrophil-to-lymphocyte ratio