Assessing Sarcoidosis Activity — Chitotriosidase versus ACE in Sarcoidosis: A Controlled Study
Introduction: To date, no suitable biomarkers have been identified for assessing sarcoidosis activity.
The study aimed to assess the sensitivity and specificity of two established biomarkers of sarcoidosis activity—serum angiotensin-converting enzyme (ACE) and serum chitotriosidase—in a population of 430 patients with sarcoidosis.
The markers were also analysed in a control group of 264 healthy participants.
Methods: Four hundred and thirty patients with biopsy-proven sarcoidosis were divided into active and inactive disease groups and into acute and chronic sarcoidosis groups. In a subgroup of 55 patients, sarcoidosis activity was also assessed with F18 fluorodeoxyglucose positron-emission tomography (18F-FDG-PET). Serum chitotriosidase and ACE levels were not normally distributed, so non-parametric tests were used for statistical analysis.
Results: Serum chitotriosidase levels were almost six times higher in patients with active sarcoidosis than in the control group and in patients with inactive disease. A serum chitotriosidase level of 100 nmol/mL/h showed 82.5% sensitivity and 70.0% specificity. A cut-off value of 32.0 U/L for serum ACE activity showed 66.0% sensitivity and only 54.0% specificity.
A statistically significant association was found between focal granulomatous activity detected by 18F-FDG PET/CT and serum chitotriosidase levels, whereas no such correlation was found with ACE. Serum chitotriosidase levels correlated significantly with disease duration (P < 0.0001). Serum chitotriosidase was also significantly associated with clinical outcome categories (COS) (p = 0.272, P = 0.001).
Conclusion: Serum chitotriosidase activity has been shown to be a reliable biomarker for assessing sarcoidosis activity and chronicity.
Source: https://scindeks.ceon.rs/article.aspx?artid=1452-82581604390P
LIVER ACE ENZYME VALUES
ACE — angiotensin-converting enzyme
Reference interval: 16–68
Serum ACE levels are elevated in 40% of patients with sarcoidosis, depending on the time since diagnosis, acute or chronic disease, disease extent, radiological stage and many other factors. However, elevated ACE values are not specific to sarcoidosis.
Elevated values may occur, for example, because of the development of a liver lesion.
Chitotriosidase
Chitotriosidase is an enzyme belonging to the glycosyl hydrolase family (also called chitinases), which participate in the degradation of chitin and chitin-like compounds. Activated macrophages secrete chitotriosidase. Elevated serum chitotriosidase levels have been detected in lysosomal diseases such as Gaucher disease, fucosidosis and galactosialidosis. Elevated levels have also been found in atherosclerosis, beta-thalassaemia, acute malaria, visceral leishmaniasis and the cerebrospinal fluid of people with multiple sclerosis.
Chitotriosidase is primarily used as a serum marker of macrophage activity in Gaucher disease. Its importance lies in its greater specificity than angiotensin-converting enzyme (ACE), which is also elevated in other granulomatous diseases, particularly miliary tuberculosis. When serum chitotriosidase values in people with tuberculosis were compared with healthy participants and people with sarcoidosis, substantially higher values were found in those with sarcoidosis.
Source: https://aqualab.rs/analize/biohemija/enzimi/hitotriozidaza/
