The following summary is from Orphanet
, a European reference portal for information on rare diseases and orphan drugs.
Orpha Number: 133
Chronic beryllium disease (CBD) is a granulomatous, interstitial lung disease that occurs in individuals who develop beryllium sensitization (BeS), a cell-mediated immune response to environmental and occupational beryllium exposure. BeS precedes the lung disease that may present with chronic dry cough, fatigue, weight loss, chest pain, and increasing dyspnea.
The number of workers exposed to beryllium has been estimated at 1 million in the US, although no accurate figure exists for the US or globally. The prevalence of sensitization in those exposed ranges from 1 - 20%. CBD among those with BeS ranges from 15-100%.
Patients with CBD can range from those who are asymptomatic to those with severe lung dysfunction. Manifestations occur a few months to a many years after exposure to beryllium and include chronic dry cough, dyspnea on exertion, chest pain, fatigue, fever, night sweats and weight loss. Additional extrapulmonary manifestations of dermatitis and skin granulomas have been reported. Progressive pulmonary fibrosis can eventually lead to cor pulmonale and respiratory failure. An increased risk of lung cancer among workers exposed to high levels of beryllium has also been observed.
CBD is caused by occupational exposure to beryllium and beryllium-containing alloys (usually by inhalation of dust or fumes but also via contact with skin). Over time, in a subset of individuals, a cell-mediated immune response to beryllium may occur, causing the development of sensitized T cells that accumulate within the lungs and eventually form granulomas which can lead to fibrosis. A genetic variant in the HLA-DPB1 gene (6p21.3) with the presence of a glutamic acid at amino acid position 69 has been associated with the development of BeS and CBD.
Diagnosis is based on a history of exposure to beryllium, characteristic clinical findings and laboratory testing. BeS can be detected with the beryllium lymphocyte proliferation test (BeLPT) where mononuclear cells from peripheral blood or bronchoalveolar lavage are exposed to beryllium in vitro. Increased proliferation of lymphocytes compared to control cells indicates BeS. Granulomatous and/or mononuclear cell infiltrates in lung tissue, are indicative of CBD. Chest x-ray, CT scan of the lungs, exercise tolerance testing and pulmonary function tests can also aid in the diagnosis.
The main differential diagnoses are sarcoidosis (most common) and tuberculosis (see these terms) as well as other occupational lung diseases (i.e. silicosis).
Management and treatment
There is no cure for CBD. Treatment involves cessation of beryllium exposure and use of corticosteroids (prednisone). Early symptomatic disease may be treated with inhaled corticosteroids along with a short acting bronchodilator. Methotrexate and other immunosuppressive therapies can reduce steroid side effects. The efficacy of corticosteroids may be limited and relapses can occur after cessation of therapy or when dose is lowered. Those with advanced disease and major breathing difficulties may require oxygen supplementation. In severe cases, a lung transplant may be suggested. Patients should refrain from smoking. CBD may be prevented by providing exposed workers with respiratory protective devices and protective clothing and by minimizing exposure through use of workplace administration and engineering controls. The BeLPT is used to identify patients early on and to define workplace areas for modification in order to ultimately reduce additional BeS and CBD cases
Prognosis varies, with some patients remaining clinically stable for many years and some experiencing a gradual worsening of symptoms over time. A debilitating course resulting in respiratory failure is also possible but regular monitoring and treatment can slow down the disease process.
Last updated: 10/20/2014