Study objectives: To evaluate new and already known biological markers of activity in patients with sarcoidosis.
Design: A 10-year prospective clinical evaluation, including a battery of delayed cutaneous hypersensitivity tests (DCHTs) and other markers of activity.
Setting: Outpatient department of a university teaching hospital.
Patients: 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.
Interventions: DCHTs and blood sample extraction every 6 months.
Measurements and results: 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).
Conclusions: 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.