High-dose dexamethasone regulates interleukin-18 and interleukin-18 binding protein in idiopathic thrombocytopenic purpura.
To evaluate the effects of high-dose dexamethasone (HD-DXM) on the balance of interleukin-18 (IL-18) and its endogenous antagonist IL-18 binding protein (IL-18BP) in ITP patients, IL-18, IL-18BP as well as IFN-gamma, IL-4 plasma levels and platelet counts were determined in 17 ITP patients receiving DXM 40 mg/day for four consecutive days and in 24 healthy subjects. Using RT-PCR, the mRNA expression of IL-18, IL-18BP, IFN-gamma, IL-4, T-box (T-bet) and GATA-binding protein 3(GATA-3) were studied in all subjects. The in vitro effects of DXM on IL-18BP and IL-18 of peripheral blood mononuclear cells (PBMCs) were studied by ELISA. HD-DXM administration increased IL-18BP and reduced IL-18 expression significantly (p<0.05), which resulted in a downregulation of IL-18/IL-18BP ratio p<0.05). In vitro, DXM had a significant effect on secretion of IL-18BP while diminishing IL-18 release from cultures of PBMCs. These results suggest that downregulation of IL-18/IL-18BP might account for its clinical efficacy of HD-DXM in active ITP.
Haematology Oncology Centre, Qilu Hospital, Shandong University, Jinan, China.
Ning-ning
NN
Shan
Xiao-juan
XJ
Zhu
Qian
Q
Wang
Chun-yan
CY
Wang
Ping
P
Qin
Jun
J
Peng
Ming
M
Hou
D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D003907:Dexamethasone / Q000494:pharmacology* / Q000627:therapeutic use; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000097:blood* / Q000235:genetics; D020382:Interleukin-18 / Q000097:blood* / Q000235:genetics; D008297:Male; D008875:Middle Aged; D016553:Purpura, Thrombocytopenic, Idiopathic / Q000097:blood* / Q000188:drug therapy*; D055815:Young Adult
D036341:Intercellular Signaling Peptides and Proteins; D020382:Interleukin-18; C118370:interleukin-18 binding protein; D003907:Dexamethasone