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.

Janus kinases inhibitors (JAKi) have an immunosuppressive effect due to the normalization of levels of proinflammatory cytokines, are used in the treatment of cytokine storm in COVID-19. This fact makes it necessary to search a predictor of an efficacy of this small-molecules. The aim of the study. To evaluate the possibility of using cytokines in predicting the efficacy of JAKi in COVID-19. Materials and methods. We examined 86 patients with COVID-19: 50 men and 36 women. The age was 57,0; (50,0–65,0) years. The SARS-CoV-2 presence was confirmed by PCR. The control group consisted of 30 healthy donors matched by sex and age. The criterion for the efficacy of JAKi was recovery, in efficacy – switching to another drug, or death. The serum concentration of IL-1β, –6, –8, –17, TNF-α and GM–CSF by ELISA was estimates using Invitrogen test-systems (USA), according to the manufacturer’s instructions. Results. In COVID-19 patients who received baricitinib (BTC), compared with healthy individuals, basal (before JAKi starting) IL-6, TNF-α serum concentrations were increased; tofacitinib (TFT) – IL-6, ruxilitinib (RLT) – IL-6 and TNF-α. A decrease of IL-1β and GM–CSF serum concentration was noted before the start of TFT and RLT. Basal concentrations of IL-6 and TNF-α are most statistically strongly associated with the diagnosis COVID-19. After 5 days of treatment with BTC, there was an increase in IL-8 level compared to the basal, a decrease in the GM–CSF concentration and a slight increase IL-6 concentration relative to healthy donors (p < 0.05 in all cases). Basal concentration of IL-17 (more than 13.9 pg/ml) indicated the possibility of successful RLT treatment (area under the ROC-curve = 0.99; AP = 99 %; DS = 80 %; OP+ = 5.0; OP– = 0.2; CI: 0.9–1.0). Conclusions. Basal serum concentration of cytokines may predict JAKi efficacy in COVID-19 patients.

Authors discuss the current state and prospects for the development of genetic testing in clinical laboratory diagnostics, recent nucleic acids sequencing technologies, their advantages and applications. Although genome-wide association studies (GWAS) have become a standard practice in identifying SNPs to determine disease susceptibility, this approach has limitations. A novel approach is proposed: integrative genome-wide association analysis (iGWAS), which relies on gene expression information to investigate the associations between SNPs and disease phenotype. Numerous studies have shown that iGWAS can significantly facilitate the search for genetic correlations and is superior to a method that relies only on the search for SNPs. Genetic testing will facilitate the molecular-based reclassification of human diseases. Authors describe the technical aspects of nanopore sequencing, the development of an iPhone app to complement miniature sequencing devices, and the world’s first mobile genomic sequence analyzer, iGenomics.

The review discusses issues related to genetic predisposition and resistance to tuberculosis. Genetic factors largely determine susceptibility to various diseases, including infections. The main focus is on the genes of the major histocompatibility complex and toll-like receptors. A number of genetic polymorphisms responsible for resistance and predisposition to tuberculosis and related clinical consequences are considered. Knowledge of molecular genetic biomarkers is necessary to identify risk groups and carry out predictive measures.

Ethylenediaminetetraacetic acid (EDTA)-dependent pseudothrombocytopenia is the phenomenon of a spurious low platelet count due to antiplatelet antibodies that cause platelet clumping in blood anticoagulated with EDTA. The aggregation of platelets in EDTA-dependent pseudothrombocytopenia is usually prevented by other anticoagulants, such as sodium citrate. EDTA-dependent pseudothrombocytopenia has never been associated with hemorrhagic diathesis or platelet dysfunction. In this article, a 2,5-year-old boy with EDTA-dependent pseudothrombocytopenia is presented because of rare presentation. We report that EDTA can induce platelet clumping, and thus spuriously low platelet counts. However, aggregation of platelets was not detected in blood samples with sodium citrate, and platelet count was normal.

The review discusses issues related to genetic predisposition and resistance to the new coronavirus infection including various factors: epidemiological, gender, ethnic and microbiome. The role of molecular genetic methods in the diagnosis of coronavirus infection is emphasized. The genetic factors largely determine the body’s susceptibility to various diseases, including infectious ones. The focus is on the genes associated with the production of interferons and enzymes that are responsible for anti-viral responses, as well as inflammatory reactions in the lungs. The first group includes genes IFNAR2 and OAS1, which control the production of antiviral proteins, while the second includes DPP9, TYK2 and CCR2, that control the behavior of monocytes. A number of other genetic polymorphisms responsible for resistance and susceptibility to infections and associated clinical consequences are discussed. The knowledge of molecular genetic biomarkers is necessary to identify risk groups, conduct predictive measures, including vaccination against COVID-19.

The review addresses issues related to genetic predisposition and resistance to sexually transmitted infections (STI). Genetic factors largely determine the susceptibility of the body to various diseases, including infectious ones. The main influence is given to the genes of the main histocompatibility complex and toll-like receptors. Some STI and genetic polymorphisms responsible for resistance and susceptibility to infections and related clinical consequences are considered. Knowledge of molecular genetic biomarkers is necessary to identify risk groups, conduct predictive measures, in particular vaccination.

Thanks to the approaches of precision medicine, great strides have been made in the diagnosis and treatment of diabetes mellitus, taking into account the individual characteristics of each patient or subgroups for monogenic subtypes of diabetes and newborn diabetes. For monogenic diabetes, molecular genetics can identify discrete etiological subtypes, the manifestation of which has profound implications for treatment, and predict the further development of concomitant clinical signs that allow early prophylaxis or supportive therapy. In contrast, second-type diabetes mellitus has a polygenic nature, which makes it difficult to define discrete clinical subtypes. The implementation of the approaches of precision medicine in the diagnosis and treatment of diabetes mellitus will allow a targeted selection of drug therapy. This review shows the successful use of precision medicine in monogenic diabetes and the possibilities of this approach to solving problems in diabetes of the second type.

We would like to present the case the manifestation of acute lymphoblastic leukemia in 2-year-old and 11-month child was treated with antiviral therapy during several month. We retrospectively analyzed hemogram’s values of the child and the importance of correct and timely interpretation of complete blood count is once again evidently demonstrated.

The review addresses issues related to genetic predisposition and resistance to infectious diseases. Genetic factors largely determine the susceptibility of the body to various diseases, including infectious ones. A genetic predisposition to tuberculosis, salmonellosis, viral hepatitis, tick-borne encephalitis, Lyme disease, HIV and others is shown. Knowledge of molecular genetic biomarkers is necessary for identifying risk groups, conducting predictive measures, in particular vaccination. The main influence is given to the genes of the main histocompatibility complex; the role of mitochondrial DNA in susceptibility to HIV infection is shown.

The objective. To calculate the reference intervals of the content of organic acids in the urine of the children of different age groups based on the results of gas chromatography with mass spectrometry; to find out their diagnostic value as biochemical markers of organic acidemia and other metabolic disorders.Materials and methods. The group consisted of 80 children with suspected organic acidemia. The control group consisted of 443 practically healthy children of different ages. The urine samples were analyzed for the content of 28 organic by gas chromatography with mass spectrometry.The results. The authors established reference intervals of 28 organic urine acids. The differences in the reference intervals defined in this work were isolated from those obtained in other studies. There were identified 37 children with abnormalities in the spectrum of organic acids according to the results of the analysis of the urine samples of patients by gas chromatography-mass spectrometry. 23 patients were diagnosed with various forms of organic acidemia on the basis of characteristic clinical and laboratory data and changes in the indicators of organic acids.The conclusion. The method of gas chromatography with mass spectrometry has proved its effectiveness and reliability for the diagnosis of hereditary diseases from the group of organic acidemias.

We would like to present the case the manifestation of acute lymphoblastic leukemia in 2-year-old and 11-month child was treated with antiviral therapy during several month. We retrospectively analyzed hemogram’s values of the child and the importance of correct and timely interpretation of complete blood count is once again evidently demonstrated.

A decrease in glomerular filtration rate (GFR) is an earlier sign of detection of chronic kidney diseases compared to an increase in urea and blood creatinine concentrations. It is impossible to measure the glomerular filtration rate directly. GFR is determined by calculating the concentration of blood creatinine or by measuring the clearance of endogenous creatinine. The work shows the influence of methods for the determination of creatinine on the results of the calculation of glomerular filtration rate and terms for the correct choice of method of measuring glomerular filtration rate in different clinical situations associated with chronic kidney disease.

For the first time, the method of ozonization permitted to determine standard values of level of unsaturation in healthy people. The samples for analysis can be isolated from blood plasma or blood serum, cellular membranes, tissues, exudates, female milk. To analyze 0.05 ml of plasma of blood serum and 200 000 cells are more than enough. The method has high sensitivity (1%), selectivity and performance (0.5-3.0 min per single analysis). The method permits to establish risk groups under mass examination of population, to forecast course and development of disease, to detect onset of latent period or complication, to control efficiency of the chosen scheme of treatment.

Knowledge acquisition is the most important and difficult process in creating an intelligent system. This involves data mining and structural organization. A data-structuring method that was developed in cooperation with experts in nonformalized areas of medicine is proposed. First, the key questions (blocks) are formulated. The answers allow an expert to find a complete solution of the stated problem. Second, the structural organization of the attribute space in each block is carried out. An example of structuring in clinico-laboratory diagnostics is given.

The article deals with the characteristics of alterations of mineral metabolism indicators in children of various age with chronic diseases ofgastrointestinal tract and having body mass of normal and different surplus degrees. The sample consisted of 127 children aged from 6 to 15 years with chronic gastroduodenitis, pancreatitis and cholecystitis. The concentration of bioelements in plasma was determined using the technique of mass spectrometry with inductively coupled plasma. The study established the increase of concentration of molybdenum 4.3 times, chrome--8.4 times and selenium--1.36 times. The revealed bioelemental misbalance impacts the overall health of children and course of disease and hence has to be accounted in case of application of treatment targeted to the correction of mineral metabolism.

Plasma trace elements (TE) were determined by atomic absorption spectrometry with electrothermal atomization and by mass spectrometry with inductively bound plasma. These techniques are highly effective and may be used to determine TE in biological samples. In children, chronic gastrointestinal diseases are accompanied by mineral metabolic disorders. In children with chronic gastrointestinal diseases whose age was 6 to 15 years and whose weight was varying, the scores of some TEs depend on a child's body weight and may be used to evaluate the degree of a pathological process.

Disorders in restructuring of T-cell receptor γ-chain in DNA from skin biopsy specimens and peripheral blood lymphocyte of patients with malignant skin lymphomas at different stages of the disease were detected by PCR. Nucleotide sequences of monoclonal T-cell receptors were determined. The study showed that DNA sequences from the skin and lymphocytes did not coincide in some cases.

The concentrations of tumor necrosis factor-alpha, interleukin-1beta, interleukin-2, interleukin-4, and the content of antibodies to H1 histone fraction in peripheral blood lymphocytes, epidermis, and serum were evaluated in patients with mycosis fungoides. It was found that as the disease progresses, cytokine synthesis is switched from Th1 to Th2 class and production of proinflammatory cytokines increases, which indirectly promotes the development of the autoimmune reaction.

Histone proteins and nucleic acid precursors were studied in 10 normal subjects and 20 patients with disseminated psoriasis before and after combined therapy including Enkad. A drop in the concentrations of H1 histones was detected in the blood lymphocytes and plasma in parallel with an increase in the concentrations of arginine-rich histones and a many-fold decrease in the acid-soluble fraction representing a pool of nucleic acid precursors. After combined therapy the ratio of lysin- and arginine-rich nuclear proteins in blood lymphocytes changed significantly and approximated the normal value; the distribution of histone-like proteins virtually did not change in the plasma, but the level of plasma and erythrocyte acid-soluble fraction normalized. This indicates positive changes in nucleic acid transport after therapy. The authors demonstrate the possibility of these findings for evaluation of the treatment efficiency.