title: Lower expression of PD-1 and PD-L1 in peripheral blood from patients with chronic ITP.
abstract: BACKGROUND
  T-cell dysregulation is a major event involved in immune thrombocytopenic purpura (ITP). Increasing data have indicated that abnormal expression of T-cell immunosuppressive receptors, such as programmed death (PD) 1 and cytotoxic T lymphocyte antigen-4 (CTLA-4), may be related to autoimmune disease pathogenesis.
  
  
  METHODS
  We analyzed the expression levels of PD-1, its ligand PD-L1, and CTLA-4 in peripheral blood mononuclear cells from 18 patients with chronic ITP by real-time polymerase chain reaction, and samples from 20 healthy individuals served as control.
  
  
  RESULTS
  The results demonstrated significantly lower expression of PD-1 (median: 0.0015) and PD-L1 (median: 0.0572) in chronic ITP patients compared with healthy individuals (PD-1: median: 0.0117, P < 0.0001; PD-L1: median: 0.5428, P < 0.0001), while there was no significant difference in the CTLA-4 expression level between the chronic ITP patients (median: 0.0818) and healthy individuals (median: 0.1667) (P = 0.219). Moreover, a positive correlation between the expression levels of PD-1 and PD-L1 (rs = 0.486, P = 0.041) and CTLA-4 and PD-1 (rs = 0.643, P = 0.004) in the chronic ITP patients was found.
  
  
  CONCLUSIONS
  Consistently lower expression of T-cell immunosuppressive receptors is a common characteristic of chronic ITP, which may be associated with its pathogenesis.
authors.affiliation: a Department of Hematology , First Affiliated Hospital, Jinan University , Guangzhou 510632 , China.
authors.forename: Jun
authors.initials: J
authors.lastname: Zhong
authors.affiliation: b Institute of Hematology, Medical College, Jinan University , Guangzhou 510632 , China.
authors.forename: Shaohua
authors.initials: S
authors.lastname: Chen
authors.affiliation: b Institute of Hematology, Medical College, Jinan University , Guangzhou 510632 , China.
authors.forename: Ling
authors.initials: L
authors.lastname: Xu
authors.affiliation: a Department of Hematology , First Affiliated Hospital, Jinan University , Guangzhou 510632 , China.
authors.forename: Jing
authors.initials: J
authors.lastname: Lai
authors.affiliation: b Institute of Hematology, Medical College, Jinan University , Guangzhou 510632 , China.
authors.forename: Ziwei
authors.initials: Z
authors.lastname: Liao
authors.affiliation: a Department of Hematology , First Affiliated Hospital, Jinan University , Guangzhou 510632 , China.
authors.forename: Tao
authors.initials: T
authors.lastname: Zhang
authors.affiliation: a Department of Hematology , First Affiliated Hospital, Jinan University , Guangzhou 510632 , China.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Yu
authors.affiliation: a Department of Hematology , First Affiliated Hospital, Jinan University , Guangzhou 510632 , China.
authors.forename: Yuhong
authors.initials: Y
authors.lastname: Lu
authors.affiliation: b Institute of Hematology, Medical College, Jinan University , Guangzhou 510632 , China.
authors.forename: Lijian
authors.initials: L
authors.lastname: Yang
authors.affiliation: b Institute of Hematology, Medical College, Jinan University , Guangzhou 510632 , China.
authors.forename: Xiuli
authors.initials: X
authors.lastname: Wu
authors.affiliation: b Institute of Hematology, Medical College, Jinan University , Guangzhou 510632 , China.
authors.forename: Bo
authors.initials: B
authors.lastname: Li
authors.affiliation: a Department of Hematology , First Affiliated Hospital, Jinan University , Guangzhou 510632 , China.|b Institute of Hematology, Medical College, Jinan University , Guangzhou 510632 , China.|c Key Laboratory for Regenerative Medicine of Ministry of Education , Jinan University , Guangzhou 510632 , China.
authors.forename: Yangqiu
authors.initials: Y
authors.lastname: Li
mesh_terms: D000328:Adult; D000368:Aged; D060890:B7-H1 Antigen / Q000096:biosynthesis* / Q000097:blood; D060908:CTLA-4 Antigen / Q000097:blood; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D061026:Programmed Cell Death 1 Receptor / Q000096:biosynthesis* / Q000097:blood; D016553:Purpura, Thrombocytopenic, Idiopathic / Q000097:blood*; D055815:Young Adult
chemical_list: D060890:B7-H1 Antigen; C423236:CD274 protein, human; D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human; C105992:PDCD1 protein, human; D061026:Programmed Cell Death 1 Receptor
keywords: CTLA-4; Immune thrombocytopenic purpura; PD-1; PD-L1