title: Elevated NKT cell levels in adults with severe chronic immune thrombocytopenia.
abstract: The aim of this study was to investigate the frequency of circulating natural killer T (NKT) cells and regulatory T cells (Tregs), as well as serum cytokine profiles, in adult chronic primary immune thrombocytopenia (ITP). The frequency of circulating T cell receptor (TCR) Vα24+Vβ11+CD3+NKT cells and CD4+CD25+CD127-/lowTregs was measured using multi-color flow cytometry. The serum concentrations of 11 cytokines were determined with a cytometric bead assay. The frequency of circulating NKT cells in patients with ITP was 0.13±0.03%, whereas the frequency in healthy controls was 0.07±0.01% of CD3+(P>0.05). However, the frequency of NKT cells in patients with ITP with platelet counts ≤20×109/l (0.22±0.05%) was significantly higher than that in patients with platelet counts >20×109/l (0.05±0.01%; P<0.05) and that in healthy controls (0.07±0.01%; P<0.05). The frequency of peripheral Tregs was comparable between patients with ITP (3.97±0.44% of CD4+) and healthy controls (3.69±0.31%; P>0.05). No significant differences were observed in the serum concentrations of 11 cytokines between patients with ITP and healthy controls, despite the fact that the serum levels of interleukin (IL)-12p70, IL-8, IL-4, interferon (IFN)-γ and tumor necrosis factor (TNF)-α in patients with ITP were higher than those in the healthy controls. The platelet count was negatively correlated with the frequency of circulating NKT cells in chronic ITP. These results indicate that NKT cells may be involved in ITP with severe thrombocytopenia, and NKT and Tregs may be important in cytokine deregulation in chronic ITP.
authors.affiliation: Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial Key Laboratory of Medical Genetics, Wenzhou Medical University, Wenzhou, Zhejiang 325035, P.R. China ; Department of Laboratory Medicine, Jinhua Hospital of Zhejiang University, Jinhua, Zhejiang 321000, P.R. China.
authors.forename: Ruilong
authors.initials: R
authors.lastname: Xu
authors.affiliation: Department of Laboratory Medicine, Jinhua Hospital of Zhejiang University, Jinhua, Zhejiang 321000, P.R. China.
authors.forename: Zhaojing
authors.initials: Z
authors.lastname: Zheng
authors.affiliation: Department of Laboratory Medicine, Jinhua Hospital of Zhejiang University, Jinhua, Zhejiang 321000, P.R. China.
authors.forename: Yongjun
authors.initials: Y
authors.lastname: Ma
authors.affiliation: Department of Laboratory Medicine, Jinhua Hospital of Zhejiang University, Jinhua, Zhejiang 321000, P.R. China.
authors.forename: Yingping
authors.initials: Y
authors.lastname: Hu
authors.affiliation: Department of Laboratory Medicine, Jinhua Hospital of Zhejiang University, Jinhua, Zhejiang 321000, P.R. China.
authors.forename: Shunhong
authors.initials: S
authors.lastname: Zhuang
authors.affiliation: Department of Hematology, Jinhua Hospital of Zhejiang University, Jinhua, Zhejiang 321000, P.R. China.
authors.forename: Bin
authors.initials: B
authors.lastname: Wei
authors.affiliation: Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial Key Laboratory of Medical Genetics, Wenzhou Medical University, Wenzhou, Zhejiang 325035, P.R. China.
authors.forename: Jianxing
authors.initials: J
authors.lastname: Lu
keywords: adult; chronic immune thrombocytopenia; cytokine profile; natural killer T cells; regulatory T cells