The usefulness of Ga-67 scanning in the evaluation of disease activity was examined in a study including 32 patients with sarcoidosis; 20 untreated and 12 treated patients. The levels of serum angiotensin-converting enzyme (ACE) were measured in all 32 patients, and bronchoalveolar lavage was performed in 10 untreated patients and 7 treated patients.
Ga-67 scanning was compared with the level of serum ACE and the numbers of lymphocytes and T-lymphocytes obtained from bronchoalveolar lavage fluid.
Ga-67 scanning was useful in the detection and assessment of subclinical lesions that were not revealed by traditional methods of investigation.
Ga-67 uptake sites not only correlated with levels of serum ACE, but also the number of T-lymphocytes of bronchoalveolar lavage fluid in both groups of patients.
No correlation was seen between the intensity of the Ga-67 uptake in lungs and the level of serum ACE in untreated patients but a positive correlation was seen in treated patients.
In the untreated group a strong correlation between the intensity of Ga-67 uptake in lungs and the number of lymphocytes and T-lymphocytes obtained from bronchoalveolar lavage fluid was noted (r=0.86, p<0.01).
These data suggested that Ga-67 scanning reflects the intensity of T-lymphocyte-mediated alveolitis. Ga-67 scanning should prove useful to assess T-cell alveolitis and to determine the disease activity stage of sarcoidosis.
