Serum
angiotensin converting enzyme (SACE) activity is used as a marker of
sarcoidosis activity and severity, but in chronic
beryllium disease (CBD) the studies of SACE give conflicting results. We examined SACE activity in 23 CBD patients, five patients with
beryllium sensitization, and 25
beryllium-exposed control subjects. CBD patients underwent complete clinical evaluation, including physical examination, pulmonary function testing, exercise physiology testing, chest radiography, and bronchoscopy with bronchoalveolar lavage and biopsy. CBD SACE activity was systematically compared with these
clinical markers of disease severity. Of CBD patients, 22% had elevated SACE activity. The test did not discriminate CBD patients from those in the
beryllium-sensitized or
beryllium-exposed groups. However, SACE activity in CBD correlated with the extent of pulmonary granulomatous
inflammation as reflected by the symptom of
breathlessness, the number of white cells in bronchoalveolar lavage (r = 0.44), the number of lavage lymphocytes (r = 0.58), the lavage lymphocyte percentage (r = 0.55), and the profusion of small opacities on chest radiograph (r = 0.41). The test-retest reliability of the assay was high (r = 0.84), as was the agreement between fresh and -70 degrees C frozen sera (r = 0.93). We conclude that SACE activity levels may reflect the extent of pulmonary granulomatous
inflammation in CBD but that the test does not help discriminate disease from nondisease.