Circulating tumour DNA (ctDNA) fragments found in blood represent a critical source of information about the tumour. However, the analysis of ctDNA is challenging due to the overwhelming presence of DNA from non-malignant cells and requires the development of highly sensitive laboratory techniques. This review discusses the major categories of ctDNA biomarkers, their detection methodologies, and explores the potential of emerging technologies within the liquid biopsy field.

Urinary tract infections (UTIs) are characterized by high prevalence in various populations, recurrent course, complications and accumulation of antibiotic resistant strains. Researchers continue to search for objective criteria for the laboratory diagnosis of associated diseases, including methods for determining bacteriuria The implementation of anautomatic bacteriological analyzer into the laboratory practice would make possible to organize screening studies of UTIs with high sensitivity and specificity, in parallel with studies of the resistant phenotypes’prevalence. This will help to create the basis for the development of highly effective and reasonable antibiotic therapy, and, in general, to improve the epidemiological situation associated with these infections.

This article discusses hematological, biochemical and coagulological markers for the diagnosis of toxic hepatitis in patients with COVID-19. The analysis of the effectiveness of these markers in a large sample of patients confirmed their importance for the early detection of toxic hepatitis b in patients with COVID-19. Blood parameters such as platelets, ALT, AST, bilirubin, as well as coagulograms and markers of protein metabolism (albumin) conducted among patients divided into control and experimental groups were analyzed. It was found that in patients with concomitant toxic hepatitis c COVID-19, the tendency of thrombocytopenia is most common in clinical blood analysis. Among the biochemical parameters of blood, liver markers increase (ALT, GGT, alkaline phosphatase, etc.). It should be noted that in 1/3 of patients, the activity of liver enzymes alanine aminotransferase and aspartate aminotransferase increases, which indicates a violation of liver function.The analysis of these data using ROC analysis showed high diagnostic accuracy of these markers in the detection of toxic hepatitis in patients with COVID-19. These studies may be important for more effective screening and further monitoring of appropriately selected treatment in such clinical situations and contributes to more effective management of this condition, leading to an improved prognosis of this disease. This study is important in the context of understanding the effects of COVID-19 on liver function.

This literature review examines data characterizing the clinical significance of the most informative laboratory markers, which make it possible not only to promptly identify the pathology of the cardiovascular system, but also to assess the risk of adverse outcomes of coronavirus infection. The most studied markers are hsTnI, NT-proBNP, D-dimer. Promising laboratory markers that require comprehensive study include osteopontin, stimulating growth factor ST2, Gal-3, copeptin, endothelin-1. With all the variety of pathological conditions that are accompanied by an increase in the concentrations of these markers, they can be considered as indicators that undoubtedly deserve close attention when assessing patients with COVID-19.

Introduction. Rapid and reliable assessment of circulating antibody levels to SARS-CoV-2 remains the current challenge for monitoring and preventing the spread of COVID-19. As the risk of emergence and dissemination of new viral strains continues to grow, epidemiologic research is also becomes increasingly important. The enzyme-linked immunosorbent assay (ELISA) is useful to assess the vaccination effectiveness and the need for revaccination, the proportion of post-disease and vaccinated individuals, and to monitor population immunity. This article provides an overview of the local ELISA kits currently available for the detection of antibodies against SARS-CoV-2 viral proteins, with a comparison to the certified kit by Mediagnost Ltd. (Germany).

The aim. Laboratory testing of seven domestic reagent kits for the determination of antibodies to SARS-CoV-2 viral proteins by ELISA in comparison with the certified test system “Anti-SARS-CoV-2 ELISA E 111-IVD” (Mediagnost Ltd., Reutlingen, Germany).

Materials and methods. The study included 80 serum samples from conditionally healthy donors: experimental group (n=70, serum samples collected after 2019) and control group (n=10, serum samples collected before 2018). The experimental group is comprised of non-infected and post-disease individuals; a proportion of those were vaccinated against COVID-19.

Results and conclusions. The data obtained indicate high reproducibility, sensitivity (100 %), and specificity for all domestic ELISA kits in detecting both post-disease (90–95 %) and vaccinated volunteers (100 %). The main quality criteria of the obtained results were comparable to those for the certified test system, “Anti-SARS-CoV-2 ELISA E 111-IVD” (Mediagnost Ltd., Germany). All kits detecting IgG to the receptor-binding domain (RBD) and to the S-glycoprotein were effective for the reliable assessment of antibody production after the vaccination. Kits for the detection of antibodies to the RBD and/or viral nucleocapsid are useful for identifying unvaccinated post-disease individuals.

The determination of thyroid-stimulating hormone (TSH) is a reliable test in the diagnosis of thyroid dysfunction. When interpreting the results of quantitative studies, clinicians and laboratory specialists most often resort to assessing the compliance of the result with reference intervals (RI). At the same time, each laboratory must determine them for the analytes being measured itself, based on the characteristics of the examined contingent, the characteristics of the analytical systems used, achieving the necessary diagnostic effectiveness of the methodology, and its own practical and economic capabilities. A retrospective analysis of TSH results obtained from patients under the age of 19 years was performed for 54970 patients without hypothyroidism, thyrotoxicosis and pituitary disorders. For this work, reagent kits “Roche Cobas”, “Mindray” and “Beckman Coulter” (ICLA) were used. As a result, RI was established for the study of TSH for three sets of reagents with appropriate equipment and for four age groups: 1 day – 6 months, 6 months – 7 years, 7–14 years, 14–19 years. This makes it possible to use RI as a screening for possible developmental pathology in childhood and to determine the limits of clinical decisions.

In the presented work, the authors propose to use for the differential diagnosis of factors contributing to calciuria in personal observations the method of visualization of multidimensional relationships using a panel of ratios of laboratory parameters of water-electrolyte metabolism. The calculation of the ratio panel included plasma values: HCT (hematocrit), MSNS (hemoglobin concentration in erythrocyte), Na (sodium), K (potassium), Ca_общ (total calcium), Cl (chlorides), F (phosphates), Kr (creatinine), Ur (urea). Along with these parameters, the following plasma parameters were determined: B-CrossLaps (osteolysis index), TP1NP (osteosynthesis index), VitD, parathyroid hormone, as well as urine pH and calcium. The results obtained, according to the authors, demonstrate the informativeness of the proposed method, which makes it possible to identify the leading complexes of bonds associated with calciuria in individual observations. At the same time, these complexes can differ significantly in their structure in different patients, finding their description in literary sources, thereby demonstrating their differential significance. The authors note that the different “images” of the connections accompanying calciuria established in this study do not exhaust all possible variants of the connections of laboratory parameters associated with the dynamics of calciuria, but as additional laboratory data of patients with various pathologies accumulate, the base of the general array can be significantly expanded. Based on the results obtained and their analysis, the authors conclude that the proposed approach is promising to use in the expert assessment of laboratory parameters as an auxiliary method in analyzing the obtained laboratory data in supporting decision-making and determining the goals of pharmacological correction of calcium metabolism disorders.

HIV infection is a significant cause of death worldwide, the number of people with HIV infection in the Russian Federation as of 2022 amounted to 1163818 people. The determination of HIV tropism is necessary for the appointment of drugs from the group of penetration inhibitors, and also opens up new opportunities in the prediction and analysis of HIV infection in a patient.

Aim. To present a description and assess the current state of methods for determining HIV tropism, to summarize known information about the influence of HIV tropism on the course of the disease, to identify topical issues related to HIV tropism and requiring solutions.

Materials and methods. A review of domestic and foreign sources devoted to methods for determining the prevalence and clinical significance of HIV tropism was carried out.

Results. For the effective administration of CCR5 antagonist drugs, preliminary analysis is necessary to establish the tropism of HIV by genotypic or phenotypic methods. The use of CCR5 antagonists is not possible if HIV can use the CXCR4 coreceptor. CXCR4 – tropism of HIV is associated with the duration of the disease, a decrease in the number of CD4 cells, AIDS, and is a negative prognostic factor. Human mutations affecting coreceptors can affect the course of infection and susceptibility to HIV.

Conclusion. The determination of HIV tropism is a useful analysis, the importance of which will increase in connection with the development of new drugs from the group of penetration inhibitors. To increase the availability of HIV tropism analysis in the Russian Federation, the creation of genotypic test systems is required. To create proprietary algorithms used in genotypic analysis, as well as laboratory testing and development of new effective drugs from the group of penetration inhibitors, it is necessary to develop a phenotypic test system. The small study of the influence of other regions of the env gene on HIV tropism, the study of HIV tropism to alternative coreceptors are urgent issues that need to be addressed.

Introduction. Harvesting of pooled platelet concentrates (PC) significantly expands the volume of transfusion support and could be used to create strategic platelet reserve.

The aim of work. To compare the quality of pooled and apheresis platelet concentrates.

Materials and methods. We studied platelet fractions (PF), isolated from the whole blood of cadre donors with Reveos system, platelet concentrates, obtained by pooling PF (Pooled PC), and platelet concentrates harvested by automatic apheresis. In all cases 2 days passed from the moment of blood donation to the platelet examination. In PC samples we studied cellular composition, morphofunctional parameters of platelets, pH and electrochemical parameters, hypotonic shock response.

Results. The morphofunctional platelet rate in PF was significantly reduced, comparing to the normal levels. At the same time, the morphofunctional parameters of platelets did not significantly differ in PF and pooled PC. The pH values, the total content of platelets and leukocytes in the pooled PC corresponded to the requirements of The rules for procurement, storage, transportation and clinical use of donated blood and its components (2019). The total platelet count, the level of annexin-positive platelets, did not significantly differ in apheresis PC and pooled PC, hypotonic shock response was correct in apheresis PC and pooled PC. On the other hand, the level of platelets with granules in pooled PC was 1,8 times lower than in apheresis PC, other morphofunctional parameters of platelets in pooled PC were also reduced. Pooled PC were characterized by more positive level of open circuit potential and lower antioxidant capacity compared with apheresis PC on the same storage time.

Conclusions. Platelet pooling with Reveos system is acceptable for obtaining PC doses that comply with Technical Regulations. Nevertheless, methods of pooled PC harvesting need further optimization.

The main method for monitoring the laboratory effectiveness of antiplatelet drugs in modern clinical practice is aggregometry, but this method is not without limitations. In this connection, there is an objective need to develop alternative methods. One of the promising areas is the method of Raman spectroscopy (RS).

Objective: development of a method to detect high residual platelet reactivity (RPR) in patients with CVD receiving acetylsalicylic acid (ASA) or clopidogrel by giant Raman spectroscopy (GRS) using an original optical biosensor.

Material sand Methods. Platelet-rich plasma of patients with cardiovascular diseases (CVD) was investigated by Raman spectroscopy using an original optical biosensor. Platelet aggregation activity was investigated using a Siemens PFA-200 aggregometer with three types of cartridges – Collagen/EPI, Collagen/ADP, and P2Y. Fisher’s linear discriminant analysis was performed using Statistica 13.0 package.

Results. Raman spectra analysis using different values of frequency shifts (970 cm-1 or 1590 cm-1), allows to evaluate laboratory ineffectiveness separately for ASA and clopidogrel. Thus, the number of patients with high residual platelet reactivity (RPR) was 41.7 % ± 6.3 % with ASA and 36.7 % ± 6.2 % with clopidogrel therapy; similar values using aggregometry were 43.5 % ± 10.3 % and 30.4 % ± 9.6 %.

Conclusion. Application of the method of Raman spectroscopy using the original optical biosensor allows to distinguish patients with high RPR in the population of patients with CVD receiving antiaggregant therapy.

Research objective. To analyze the epidemiological features of chronic hepatitis in the Russian Federation and in the Samara region.

Materials and methods. The data of official statistics were analyzed: the materials of the Federal Service for Supervision in the Field of Consumer Protection and Human Welfare, the Office of the Federal Service for Supervision in the Field of Consumer Protection and Human Welfare in the Samara Region.

Results. The long-term dynamics of the incidence of newly diagnosed chronic hepatitis B in the Russian Federation and the Samara region in 1999–2021 was synchronous. In 1999–2001 the incidence of HCV (Chronic hepatitis B) in the Russian Federation and the Samara region had maximum values of 16,00⁄0000–22,50⁄0000. In the Samara region, it was higher than in the country. As a result of systematic measures to vaccinate the population against HCV during the period of mass immunization (2006–2021), the rate of decrease in the incidence of HCV in the Samara region decreased from 14,5 0⁄0000 to 2,40⁄0000 and in the country – from 14,0 0⁄0000 to 4,50⁄0000. The introduction of immunization of the child population against HCV in the Samara region had a positive effect on the incidence of HCV. From 2000 to 2021, the incidence of HCV decreased by 9,4 times. If in 2000 the incidence of children with HCV was 4,20⁄0000 in the Russian Federation, in 2002–7,30⁄0000 in the Samara region, then in 2021 in the Russian Federation it decreased to 0,080⁄0000, no cases were registered in the Samara region.

The key distinctive features and application opportunities of the upgraded semi-automatic coagulometers APG2–03-P, APG2–03-Ph, APG4–03-P, APG4–03-Ph are described.

Reference intervals (RI) and clinical decision limits (CDL) are an important part of th e medical information needed to interpret the results of a laboratory tests. The emphasis is on the need to distinguish between the two concepts. RI allows to assess the compliance of the patient’s result with the values detected in a healthy population with a certain probability. CDL is associated with specific diseases and medical risks and may be more significant for clinical decision-making than RI. When interpreting RI and CDL, it is necessary to take into account the possibility of divergence of results on different analytical systems as a potential source of erroneous medical decisions.