title: Upregulation of CD19⁺CD24(hi)CD38(hi) regulatory B cells is associated with a reduced risk of acute lung injury in elderly pneumonia patients.
abstract: Acute lung injury (ALI) is a common complication in elderly pneumonia patients who have a rapid progression, and is accompanied by a high mortality rate. Because the treatment options of ALI are limited to supportive care, identifying pneumonia patients who are at higher risk of ALI development is the emphasis of many studies. Here, we approach this problem from an immunological perspective by examining CD19(+)CD24(hi)CD38(hi) B cells, an important participant in acute and chronic inflammation. We find that elderly pneumonia patients have elevated CD19(+)CD24(hi)CD38(hi) B cell frequency compared to healthy individuals. This B cell population may express a higher level of IL-10, which has been was shown to suppress CD4(+) T cell-mediated proinflammatory cytokine interferon gamma (IFNg) and tumor necrosis factor alpha (TNFa) production, through an IL-10-dependent mechanism. We also observe that the frequency of CD19(+)CD24(hi)CD38(hi) B cell is positively correlated with the frequency of CD4(+)CD25(+)Foxp3(+)Tregs in peripheral blood. Moreover, consistent with CD19(+)CD24(hi)CD38(hi) B cell's anti-inflammatory role, we find that pneumonia patients who later developed ALI have reduced level of CD19(+)CD24(hi)CD38(hi) B cells. Together, our results demonstrated that CD19(+)CD24(hi)CD38(hi) B cells in pneumonia patients possess regulatory function in vivo, and are associated with a reduced ALI risk.
authors.affiliation: Department of Internal Medicine, Emergency Center, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, 200120, China.
authors.forename: Haihan
authors.initials: H
authors.lastname: Song
authors.affiliation: Department of Geriatrics, The Affiliated Hospital of Inner Mongolia Medical University, Hohhot, 010050, China.
authors.forename: Jianjun
authors.initials: J
authors.lastname: Xi
authors.affiliation: ICU, Affiliated Bayi Brain Hospital, General Hospital of Beijing Military Command, Beijing, 100700, China.
authors.forename: Guang-Gang
authors.initials: GG
authors.lastname: Li
authors.affiliation: Department of Internal Medicine, Emergency Center, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, 200120, China.
authors.forename: Shumin
authors.initials: S
authors.lastname: Xu
authors.affiliation: Department of Internal Medicine, Emergency Center, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, 200120, China.
authors.forename: Chunmei
authors.initials: C
authors.lastname: Wang
authors.affiliation: Department of Internal Medicine, Emergency Center, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, 200120, China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Cheng
authors.affiliation: Department of Internal Medicine, Emergency Center, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, 200120, China.
authors.forename: Hongqiang
authors.initials: H
authors.lastname: Li
authors.affiliation: Department of Internal Medicine, Emergency Center, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, 200120, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Internal Medicine, Emergency Center, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, 200120, China.
authors.forename: Xiandong
authors.initials: X
authors.lastname: Liu
authors.affiliation: Department of Internal Medicine, Emergency Center, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, 200120, China. jianwenbai1019@126.com.
authors.forename: Jianwen
authors.initials: J
authors.lastname: Bai
mesh_terms: D055371:Acute Lung Injury / Q000209:etiology / Q000276:immunology* / Q000503:physiopathology; D000368:Aged; D000369:Aged, 80 and over; D018941:Antigens, CD19 / Q000378:metabolism*; D060151:B-Lymphocytes, Regulatory / Q000276:immunology / Q000378:metabolism*; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D002681:China; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D015577:Geriatric Assessment; D006769:Hospitals, General; D006801:Humans; D008297:Male; D011014:Pneumonia / Q000150:complications* / Q000382:microbiology / Q000503:physiopathology; D011379:Prognosis; D012016:Reference Values; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D015854:Up-Regulation
chemical_list: D018941:Antigens, CD19; D015415:Biomarkers; C000604811:CD19 molecule, human
keywords: Acute lung injury; B cells; Senior pneumonia