How is chronic beryllium disease diagnosed?
Chronic beryllium disease (CBD), caused by an allergic reaction to beryllium, is clinically similar to other granulomatous diseases such as sarcoidosis. It is often misdiagnosed if a thorough occupational history is not taken. That is, patients should provide their doctor with a history of all jobs they have held and all the exposures they know about, including any exposure to beryllium.
For an appropriate diagnosis, in addition to taking a detailed medical and occupational history and conducting a thorough medical examination, a beryllium lymphocyte proliferation test (BeLPT) needs to be performed on blood and/or lung lavage cells. This test determines if your immune system is reacting to beryllium. Positive or suspicious findings warrant referral to a pulmonologist or other doctor who knows about beryllium disease for further evaluation and treatment.
Most physicians require two positive blood BeLPT results to define sensitization, or the immune response to beryllium. Patients with positive blood BeLPT results should undergo further testing to determine if they have CBD. Usually this includes bronchoscopy with bronchoalveolar lavage (BAL) and transbronchial biopsy to search for evidence of pathology that confirms the diagnosis. Chest radiograph or chest computed tomography (CAT scan) can be used to look for abnormalities consistent with CBD and sometimes may be used in place of a biopsy to determine if there is disease.
Although the BeLPT is the most straightforward way to establish beryllium sensitization, under certain circumstances, an individual may be diagnosed with CBD without having a positive blood BeLPT. In a situation where a patient has received one or more normal or borderline BeLPTs, a bronchoscopy and lung tissue biopsy can be used to confirm the presence of granulomas consistent with CBD. Sometimes the lung lavage cells react to beryllium, producing a positive BeLPT, even if the blood cells do not show this response. It was reported that tobacco smoking can sometimes interfere with the interpretation of the BeLPT.