targeting oxidative stress in chronic beryllium disease

Conditions: Chronic Beryllium Disease

Summary: the purpose of this study is to understand if a drug called mesalamine helps to control inflammation associated with chronic beryllium disease (cbd). we hypothesize that in cbd subjects treated with prednisone, mesalamine treatment will enhance the immunosuppressive effects of prednisone, and thus reduce the immune response to beryllium.

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.

Eligibility criteria:
inclusion criteria: * diagnosis of chronic beryllium disease based on the criteria below: 1. history of beryllium exposure, and; 2. positive blood and/or bronchoalveolar lavage beryllium lymphocyte proliferation tests (belpt), and; 3. biopsy-proven pathologic changes consistent with cbd-non-caseating granulomas and/or mononuclear cell interstitial infiltrates, and; 4. positive bronchoalveolar lavage (bal) belpt and \> 15% lymphocytes in bal fluid. exclusion criteria: * history of hepatic disease * history of renal disease * hypersensitivity to pentasa (5-asa) or salicylates. * pregnancy * presence of another disease that may be expected to significantly affect patient mortality (e.g., hiv), severe cor pulmonale); * the use of blood thinners. * current use of tobacco (smoking or otherwise) in the past 6 months * patient inability to participate in the study, such as inability to undergo venipuncture and bal procedures (if undergoing bronchoscopy) that form part of the inclusion/exclusion criteria or part of the outcome measure. if undergoing bronchoscopy: * severe room air hypoxemia (precluding transbronchial lung biopsy and/or bal), e.g., po2 \< 45 (denver altitude 5,280 feet);

Keywords: berylliosis beryllium disease