Abstract
Sarcoidosis is a granulomatous disease of unknown nature. The diagnosis of sarcoidosis is difficult, including due to the lack of uniform diagnostic criteria and specific diagnostic biological markers. The criteria for diagnosis are rather conditional, and reliable exclusion of alternative causes of granulomatous disease is not always possible. A biomarker is an indicator reflecting the biological processes underlying the disease, as well as reactions to treatment. When identifying a new biomarker, it is necessary to focus on its high specificity, diagnostic sensitivity, and reproducibility. The publication reflects data on research in the field of studying new biological markers of sarcoidosis.Existing biomarkers (angiotensin converting enzyme, soluble IL-2 receptor, chitotriosidase) are actively used in clinical practice to diagnose and evaluate the activity of the disease. Some other biomarkers (for example, the chemokine ligand CC 18) can be used to predict the formation of fibrosis and assess the response to therapy (serum amyloid A). The study of new biomarkers is necessary not only to improve understanding of the pathogenesis of sarcoidosis, but also for diagnostic purposes. Thus, when studying the axis of hypoxia-induced angiogenesis (HIF)–1a — vascular endothelial growth factor (VEGF) — inhibitor of growth factor 4-(ING4) in patients with sarcoidosis, a decrease in the expression of both protein and HIF-1a mRNA levels in sarcoid granulomas was revealed, as well as abundant expression of VEGF and ING4 in epithelioid cells in granulomatous tissue, which makes it possible to consider it as one of the potential markers for introduction into clinical practice. Modern big data studies using Omics have revealed potential biomarkers — annexin A11 and NOTCH4, CTSS et al. However, the use of a blood transcriptome by proteomes of alveolar macrophages may be too complicated for clinical practice.