title: Increased interleukin‑9 and CD4+IL-9+ T cells in patients with systemic             lupus erythematosus.
abstract: Systemic lupus erythematosus (SLE) is an autoimmune disease of unknown origin             affecting all the organ systems. Apart from genetic and environmental factors,             autoantibody and immune complex deposition as well as cytokine imbalances contribute             to immune dysfunction. Interleukin‑9 (IL-9) is a T cell-derived factor preferentially             expressed by CD4+ T cells and it has been characterized in human and murine systems.             IL-9 targets cells of the lymphoid, myeloid and mast cell lineages, and is likely             to contribute to the development of allergic and autoimmune diseases such as asthma,             arthritis, multiple sclerosis and experimental autoimmune encephalomyelitis (EAE).             Nevertheless, until recently there have been no studies on its role in SLE in             humans. In the present study, the mRNA and serum IL-9 levels in the peripheral             blood of SLE patients and healthy controls were assessed using real-time PCR and             enzyme-linked immunosorbent assay (ELISA), respectively. Flow cytometry was used             to analyze the percentages of CD4+IL-9+ T cells in SLE patients. Moreover, differences             between the groups and the effect of glucocorticoids were analyzed. The results             showed that the plasma concentration and mRNA levels of IL-9 were significantly             elevated in SLE patients compared with the healthy controls. The percentages of             CD4+IL-9+ T cells were also increased in SLE patients. In addition, serum IL-9             levels and the percentages of CD4+IL-9+ T cells were correlated with the SLE disease             activity index (SLEDAI). Additionally, the percentages of CD4+IL-9+ T cells and             serum IL-9 levels in 8 untreated active SLE patients were decreased at 1, 2 and             3 weeks after treatment with methylprednisolone. In conclusion, we provide evidence             that IL-9 is increased in SLE patients. Moreover, it is described for the ﬁrst             time that high expression of IL-9 levels and the percentages of CD4+IL-9+ T cells             correlate with disease activity and severity. This suggests an important role             of IL-9 in the pathogenesis of SLE.
authors.affiliation: Department of Nephrology, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215004, PR China.
authors.forename: Han
authors.initials: H
authors.lastname: Ouyang
authors.forename: Yongbing
authors.initials: Y
authors.lastname: Shi
authors.forename: Zhichun
authors.initials: Z
authors.lastname: Liu
authors.forename: Sheng
authors.initials: S
authors.lastname: Feng
authors.forename: Lingyun
authors.initials: L
authors.lastname: Li
authors.forename: Nan
authors.initials: N
authors.lastname: Su
authors.forename: Ying
authors.initials: Y
authors.lastname: Lu
authors.forename: Shumin
authors.initials: S
authors.lastname: Kong
mesh_terms: D000328:Adult; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D002478:Cells, Cultured; D005260:Female; D005434:Flow Cytometry; D005938:Glucocorticoids / Q000494:pharmacology / Q000627:therapeutic use; D006801:Humans; D016906:Interleukin-9 / Q000097:blood* / Q000235:genetics; D008180:Lupus Erythematosus, Systemic / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D008297:Male; D008775:Methylprednisolone / Q000494:pharmacology / Q000627:therapeutic use; D008875:Middle Aged; D012333:RNA, Messenger / Q000378:metabolism
chemical_list: D005938:Glucocorticoids; D016906:Interleukin-9; D012333:RNA, Messenger; D008775:Methylprednisolone