title: Soluble Programmed Death 1 (PD-1) Is Decreased in Patients With Immune Thrombocytopenia (ITP): Potential Involvement of PD-1 Pathway in ITP Immunopathogenesis.
abstract: Immune thrombocytopenia (ITP) is an autoimmune disease characterized by dysregulation of T cells. Programmed death (PD) 1 and programmed death 1 ligand 1 (PD-L1) are cosignaling molecules, and the major role of the PD-1 pathway is the inhibition of self-reactive T cells and to protect against autoimmune diseases. We measured levels of serum soluble PD 1 (sPD-1) and serum soluble PD-L1 (sPD-L1) in 67 patients with ITP (24 newly diagnosed ITP [ndITP], 43 chronic ITP [cITP]) and 21 healthy controls (HCs). We determined decreased serum sPD-1 levels both in patients with ndITP and in patients with cITP when compared to HC. Moreover, there was a positive correlation between sPD-1 levels and platelet counts. The sPD-L1 levels were decreased in patients with ndITP when compared to patients with cITP. This is the first study investigating PD-1 signaling pathway in ITP. Decreased sPD-1 levels may have a role in ITP pathogenesis as without the inhibitory regulation of PD-1, sustained activation of T cells may cause inflammatory responses which is the case in ITP.
authors.affiliation: Department of Hematology, Kocaeli University, Kocaeli, Turkey ebirtas@yahoo.com.
authors.forename: Elif
authors.initials: E
authors.lastname: Birtas Atesoglu
authors.affiliation: Department of Hematology, Kocaeli University, Kocaeli, Turkey.
authors.forename: Pinar
authors.initials: P
authors.lastname: Tarkun
authors.affiliation: Department of Hematology, Kocaeli University, Kocaeli, Turkey.
authors.forename: Esra Terzi
authors.initials: ET
authors.lastname: Demirsoy
authors.affiliation: Department of Hematology, Kocaeli University, Kocaeli, Turkey.
authors.forename: Ayfer
authors.initials: A
authors.lastname: Geduk
authors.affiliation: Department of Hematology, Kocaeli University, Kocaeli, Turkey.
authors.forename: Ozgur
authors.initials: O
authors.lastname: Mehtap
authors.affiliation: Department of Internal Medicine, Kocaeli University, Kocaeli, Turkey.
authors.forename: Adnan
authors.initials: A
authors.lastname: Batman
authors.affiliation: Department of Internal Medicine, Kocaeli University, Kocaeli, Turkey.
authors.forename: Fatih
authors.initials: F
authors.lastname: Kaya
authors.affiliation: Department of Biochemistry, Kocaeli University, Kocaeli, Turkey.
authors.forename: Mustafa Baki
authors.initials: MB
authors.lastname: Cekmen
authors.affiliation: Hematology Department, Anadolu Medical Center Hospital, Kocaeli, Turkey.
authors.forename: Zafer
authors.initials: Z
authors.lastname: Gulbas
authors.affiliation: Department of Hematology, Kocaeli University, Kocaeli, Turkey.
authors.forename: Abdullah
authors.initials: A
authors.lastname: Hacıhanefioglu
mesh_terms: D000328:Adult; D000368:Aged; D002908:Chronic Disease; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010976:Platelet Count; D061026:Programmed Cell Death 1 Receptor / Q000097:blood* / Q000276:immunology; D016553:Purpura, Thrombocytopenic, Idiopathic / Q000097:blood* / Q000175:diagnosis / Q000276:immunology; D015398:Signal Transduction / Q000276:immunology; D012995:Solubility
chemical_list: C105992:PDCD1 protein, human; D061026:Programmed Cell Death 1 Receptor
keywords: programmed death 1; programmed death 1 ligand 1; thrombocytopenia