Leptin enhances in vitro secretion of IgG antiplatelet antibodies by splenocytes and peripheral blood mononuclear cells from patients with chronic idiopathic thrombocytopenic purpura.
Chronic idiopathic thrombocytopenic purpura (ITP) is an organ-specific autoimmune disease characterized by the production of antibodies against antigens on the membranes of platelets, resulting in enhanced destruction of the platelets by macrophages. Leptin, a cytokine-like hormone, plays a role in the pathogenesis of several autoimmune diseases. In this study, we observed significantly increased plasma leptin levels combined with decreased soluble leptin receptor (sOB-R) levels in 18 chronic ITP patients compared with 14 controls. We also demonstrated significantly elevated mRNA expression of long form leptin receptor (Ob-Rb) on peripheral blood mononuclear cells (PBMCs) from chronic ITP patients. Treatment with recombinant leptin or serum with high leptin levels enhanced in vitro secretion of IgG antiplatelet antibodies by splenocytes and PBMCs from patients with chronic ITP. After depletion of CD4(+) T cells from splenocytes, leptin lost this function. Further studies showed that leptin could increase platelet reactive T cells. These findings suggest that leptin may be involved in the pathogenesis of chronic ITP and might offer a potential target for the treatment of this disease.
Ren
He
H
State Key Laboratory of Experimental Hematology, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300020, PR China.
Zhao
Hui
H
Wang
Tingting
T
Yang
Yanhui
Y
Han
Zhibo
Z
Liu
Bin
B
Wu
Zida
Z
Tao
Jie
J
Zhou
Bin
B
Zhang
Lei
L
Yang
Renchi
R
Han
Zhong Chao
ZC
D000328:Adult; D001323:Autoantibodies / Q000097:blood; D001792:Blood Platelets / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology; D002478:Cells, Cultured; D002908:Chronic Disease; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D020738:Leptin / Q000096:biosynthesis / Q000097:blood / Q000494:pharmacology*; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D016553:Purpura, Thrombocytopenic, Idiopathic / Q000097:blood / Q000276:immunology*; D013154:Spleen / Q000166:cytology / Q000187:drug effects / Q000276:immunology*
D001323:Autoantibodies; D007074:Immunoglobulin G; D020738:Leptin