Early pulmonary physiologic abnormalities in beryllium disease.

By using the beryllium-specific blood lymphocyte transformation test (BeLT) as a screening tool, it is possible to identify beryllium disease before clinical symptoms or radiographic abnormalities develop. Little is known about the early pulmonary physiologic abnormalities in granulomatous lung diseases. We compared two groups: (1) "surveillance-identified" early beryllium disease patients, detected using the blood BeLT in workplace screening projects (n = 21), and (2) "clinically identified" beryllium disease patients who presented with symptoms or radiographic abnormalities (n = 15). We measured spirometry, lung volumes, diffusing capacity for carbon monoxide, arterial blood gases, and maximal exercise capacity. Physiologic abnormalities occurred in 12 of 21 (57%) surveillance-identified patients. The most common derangement was a rise in the dead space to tidal volume ratio (VD/VT) during exercise, suggesting a pulmonary vascular abnormality. None of the surveillance-identified patients had pure restriction, and only one of 21 had an abnormal diffusing capacity. In comparison, 93% of clinically identified beryllium disease patients had one or more abnormalities, the most sensitive indicator being the exercise capacity. One-third had airflow limitation. Resting arterial blood gas analysis was abnormal in seven of 15 (47%), whereas diffusing capacity was low in only five of 15 (33%). Clinically identified patients performed less work, had more severe gas exchange abnormalities, and had higher VD/VT at maximal exercise than did surveillance-identified patients. We conclude that alterations in gas exchange and the pulmonary vascular bed occur early in beryllium disease.