Journal Article

Relative Corticosteroid Insensitivity of Peripheral Blood Mononuclear Cells in Severe Asthma

Meah, Sally, Khorasani, Nadia, Bhavsar, Pankaj, Barnes, Peter J, Hew, Mark, Torrego, Alfons, National Heart Lung and Blood Institute's Severe Asthma Research Program, Fan Chung, Kian, Adcock, Ian

2006

Overview

Abstract Rationale and Objectives Patients with severe asthma have a poor therapeutic response to corticosteroid therapy, and corticosteroid responsiveness cannot be easily measured in these patients. We hypothesized that this poor response is associated with a reduced effect of corticosteroids to inhibit cytokine release from activated peripheral blood mononuclear cells (PBMCs). Methods Patients with severe asthma were defined by American Thoracic Society criteria. We compared the suppression of LPS-induced cytokine release (monocyte chemotactic protein-1 [MCP-1], macrophage inflammatory protein [MIP] 1α, RANTES, tumor necrosis factor α, interleukin 1β (IL-1β), IL-8, IFN-γ, IL-6, IL-10, and granulocyte-macrophage colony–stimulating factor [GM-CSF]) by dexamethasone from PBMCs of patients with severe asthma (n = 16), patients with nonsevere asthma (n = 19), and normal volunteers (n = 10). Results There was no difference in baseline spontaneous or stimulated release of these cytokines among groups. LPS-induced release of 10 cytokines was less suppressed by dexamethasone (10−6 M) in patients with severe asthma compared with patients with nonsevere asthma, with statistical significance achieved for IL-1β (p < 0.03), IL-8 (p < 0.03), and MIP-1α (p < 0.003), and borderline significance for IL-6 (p = 0.054). There was less difference between the two groups for dexamethasone at 10−8 M. Nuclear histone deacetylase (HDAC) and histone acetyltransferase activities were reduced in patients with severe asthma compared with patients with nonsevere asthma (p < 0.01). HDAC activity reduction correlated directly to the degree of steroid insensitivity of GM-CSF (r = 0.57, p < 0.01) and IFN-γ (r = 0.56, p < 0.05) release. Reduction in histone acetyltransferase activity related to corticosteroid use rather than asthma severity. Conclusions Patients with severe asthma have diminished corticosteroid sensitivity of PBMCs when compared with patients with nonsevere asthma, associated with a reduction in HDAC activity that parallels the impaired corticosteroid sensitivity.

• Publisher: Am Thoracic Soc,Oxford University Press,American Lung Association,American Thoracic Society
• Subject: Adult / Airway management / Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy / Asthma / Asthma - blood / Asthma - drug therapy / Asthma - physiopathology / B. Asthma and Allergy / Biological and medical sciences / Blood. Blood and plasma substitutes. Blood products. Blood cells. Blood typing. Plasmapheresis. Apheresis / Bone marrow, stem cells transplantation. Graft versus host reaction / Cell Nucleus - enzymology / Cytokines / Cytokines - analysis / Dexamethasone - pharmacology / Drug Resistance / Female / Glucocorticoids - pharmacology / Glucocorticoids - therapeutic use / Granulocytes / Histone Acetyltransferases - metabolism / Histone Deacetylases - metabolism / Humans / Intensive care medicine / Leukocytes, Mononuclear - drug effects / Leukocytes, Mononuclear - enzymology / Lipopolysaccharides / Male / Medical sciences / Middle Aged / Proteins / Steroids / Transfusions. Complications. Transfusion reactions. Cell and gene therapy / Tumor necrosis factor-TNF / Yeast