title: Low-Density Granulocytes Are Elevated in Mycobacterial Infection and Associated with the Severity of Tuberculosis.
abstract: Tuberculosis remains a global health problem caused by infection with Mycobacterium tuberculosis. Numerous studies have established a close correlation between the development of tuberculosis and the roles of neutrophils. Recently, a distinct population of CD15+ granulocytes was found to be present in the peripheral blood mononuclear cell (PBMC) fraction in humans. This population of granulocytes, termed low-density granulocytes (LDGs), was reported to be elevated and associated with disease activity or severity in a number of different conditions including SLE, asthma and HIV infection. However, both the frequency and clinical significance of LDGs associated with tuberculosis are unclear. Here we determined LDG levels and made comparisons between subjects with active pulmonary tuberculosis (PTB) and healthy controls, between PTB patients with mild-to-moderate disease and patients with advanced disease, and among PTB patients following anti-tuberculous therapy of varying durations. The direct correlation between M. tuberculosis infection and LDG levels was confirmed by in vitro infection of whole peripheral blood and isolated granulocytes with mycobacteria. Our results demonstrated that PBMCs in PTB patients contained significantly elevated percentages of LDGs compared with control subjects. LDGs in tuberculosis expressed higher levels of activation markers compared to normal-density granulocytes (NDGs). M. tuberculosis induced the generation of LDGs in both whole blood and isolated NDGs from control subjects, which suggests that LDGs associated with M. tuberculosis infection are likely to originate from in situ activation. Furthermore, our results revealed that the frequency of LDGs is associated with the severity of tuberculosis.
authors.affiliation: Department of Clinical Laboratory, the First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China.
authors.forename: Yating
authors.initials: Y
authors.lastname: Deng
authors.affiliation: Department of Clinical Laboratory, the First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China.
authors.forename: Jianqing
authors.initials: J
authors.lastname: Ye
authors.affiliation: Department of Clinical Laboratory, the First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Luo
authors.affiliation: Department of Clinical Laboratory, the First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China.
authors.forename: Zhikun
authors.initials: Z
authors.lastname: Huang
authors.affiliation: Department of Tuberculosis, Jiangxi Chest Hospital, Nanchang, Jiangxi, China.
authors.forename: Yiping
authors.initials: Y
authors.lastname: Peng
authors.affiliation: Department of Clinical Laboratory, Jiangxi Chest Hospital, Nanchang, Jiangxi, China.
authors.forename: Guoliang
authors.initials: G
authors.lastname: Xiong
authors.affiliation: Department of Clinical Laboratory, the First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Guo
authors.affiliation: Department of Clinical Laboratory, the First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Jiang
authors.affiliation: Department of Clinical Laboratory, the First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China.
authors.forename: Junming
authors.initials: J
authors.lastname: Li
mesh_terms: D000328:Adult; D005260:Female; D006098:Granulocytes / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D007958:Leukocyte Count; D016256:Lewis X Antigen / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis; D017382:Reactive Oxygen Species / Q000378:metabolism; D012720:Severity of Illness Index; D014397:Tuberculosis, Pulmonary / Q000473:pathology*
chemical_list: D016256:Lewis X Antigen; D017382:Reactive Oxygen Species