BACKGROUND: Sarcoidosis is a granulomatous disease which can afflict virtually any tissue in the human body, most commonly the mediastinal lymph nodes and lungs. Pathohistological confirmation is the gold standard in establishing a diagnosis
however, determining the activity of the disease requires multiple clinical, radiographic and laboratory procedures. PET/CT scan is considered the gold standard for determining the presence of active granuloma but has several significant limitations (radioactive material, cost, overall access to device). ACE and chitotriosidase are biomarkers used for diagnosing sarcoidosis and could have a place in determining the activity of the disease when compared with the results of PET/CT scans. METHODS: We have compared the levels of ACE and chitotriosidase with the levels of SUVmax values in patients with sarcoidosis. RESULTS: SUVmax and chitotriosidase levels were significantly correlated at the baseline and after the follow-up period, regardless of gender, age, duration of disease and radiography stage, while SUVmax and ACE levels were not. Chitotriosidase also showed a significant predictive ability to decrease the activity of sarcoidosis, which represented the decrease of SUVmax as the effect of therapy compared with ACE. CONCLUSIONS: In the absence of an ideal biomarker for sarcoidosis (high sensitivity, specificity and stability), chitotriosidase can be used in determining the activity of the disease, as it has shown a significant correlation to the gold standard-PET/CT scan.