Delayed Cutaneous Hypersensitivity Tests and Lymphopenia as Activity Markers in Sarcoidosis

To evaluate new and already known biological markers of activity in patients with sarcoidosis. A 10-year prospective clinical evaluation, including a battery of delayed cutaneous hypersensitivity tests (DCHTs) and other markers of activity. Outpatient department of a university teaching hospital. Forty patients with biopsy-proven sarcoidosis were prospectively evaluated every 6 months. In this study, only the visits that fulfilled the situation of active period (AcP) or of asymptomatic period (AsP) were taken into account. Twenty-one visits were considered to be in the AcP, and 26 were considered to be in the AsP. Seven patients were studied both in the AcP and the AsP. DCHTs and blood sample extraction every 6 months. The mean diameter of the cutaneous wheal for each antigen (AG) was lower in the AcP group than in the AsP group (candidine, p < 0.0001; tuberculin, p < 0.0009; trichophytin, p < 0.02; streptokinase-streptodornase, p < 0.001). Also, the mean (± SD) diameter for the four AGs taken together was lower in the AcP group (2.3 ± 4.2 mm) than in the AsP group (16.8 ± 9.3 mm; p < 0.0001). The mean serum angiotensin-converting enzyme (S-ACE) value was higher in the AcP group than in the AsP group (p < 0.02). A low lymphocyte count and a percentage of the lymphocyte count (< 20%) also were detected more frequently in the AcP group than in the AsP group (p < 0.02 and p < 0.0001, respectively). DCHTs appear to be a simple, reliable, and easily performed marker of inflammatory activity in sarcoidosis patients. Furthermore, serum total and differential lymphocyte count and the S-ACE level proved to be useful inflammatory markers in this study.