Targeting Oxidative Stress in Chronic Beryllium Disease

• Beryllium lymphocyte proliferation responses (BeLPT) [ Time Frame: baseline and week 6 ] [ Designated as safety issue: No ]
  Primary endpoints are beryllium proliferation responses (BeLPT) in PBMCs and BAL cells.
  
  

• Th1 cytokines [ Time Frame: baseline and week 6 ] [ Designated as safety issue: No ]
  Secondary outcomes include changes in Th1 cytokines (e.g. INFγ)
  
  
• Steady-state GSH levels [ Time Frame: baseline and week 6 ] [ Designated as safety issue: No ]
  Secondary outcomes include changes in steady-state GSH levels in beryllium specific CD4+ T cell, HDAC2 levels
  
  
• HDAC2 levels [ Time Frame: baseline and week 6 ] [ Designated as safety issue: No ]
  Secondary outcomes include changes in HDAC2 levels
  
  
• Glucocorticoid receptors [ Time Frame: baseline and week 6 ] [ Designated as safety issue: No ]
  Secondary outcomes include changes in glucocorticoid receptors modification in PBMCs and BAL cells.
  
  
• Lung function [ Time Frame: baseline and week 6 ] [ Designated as safety issue: No ]
  Secondary outcomes include changes in lung function, which will be assessed with spirometry and DLCO.
  
  

The overall goal of this study is to understand the role of oxidative stress as a potential therapeutic target in the pathogenesis of chronic beryllium disease (CBD). CBD is an inflammatory hypersensitivity lung disease that occurs in an estimated 800,000 beryllium-exposed workers in the United Sates. CBD is characterized by the presence of pulmonary non-caseating granulomas with accumulation of macrophages and beryllium specific CD4+ T cells (Newman et al. 1998). Upon beryllium stimulation in vitro, beryllium specific CD4+ T cells proliferate and produce Th1 cytokines (i.e. TNF-α, IFN-γ, and IL-2) at unusually high levels (Tinkle et al. 1997). The molecular mechanism(s) by which beryllium regulates the chronic production of these cytokines is unknown. Exciting preliminary studies indicate that beryllium alters the redox status of T cells which may adversely modulate the immune response in CBD. Based on these points, a novel hypothesis is proposed: 1) oxidative stress enhances the T cells response to antigen and this enhancement may explain both the excessive cytokine response and the pathogenesis of pulmonary granulomas in CBD and; 2) an inherent difference in T cell antioxidant status is a critical factor in the pathogenesis of CBD. This proposal is a pilot clinical trial examining an approved drug for the treatment of ulcerative colitis (5-amino salicylic acid, 5-ASA), which has anti-inflammatory and antioxidant properties, as a potential new approach for CBD treatment. In this clinical trial, 40 CBD subjects already treated with prednisone, will be treated with either placebo or 5-ASA to determine it effects on the beryllium stimulated immune response in the lung by undergoing bronchoscopy with bronchoalveolar lavage and in blood by undergoing venipuncture before and after 6 weeks of treatment with 5-ASA. As a secondary outcome, we will also assess subjects clinical response to this short course of 5-ASA using spirometry. Bronchoscopies are optional. Patients have the option to participate by undergoing venipuncture and lung function tests only.