The hormonal system aldosterone synthase-aldosterone-mineralcorticoid receptor plays a key role in kidney damage, progression of CKD and increased blood pressure in patients with diabetic and nondiabetic nephropathy. The steroid antagonist of mineralcorticoid (MC) receptors spironolactone and its replacement eplerenone are recommended to be included in combination with RAS inhibitors to control blood pressure and reduce urinary protein loss in hypertensive patients with stages C1-C3a of CKD. However, the use this drugs in CKD is limited due to the risk of hyperkalemia, gynecomastia and other unwanted side effects. Recently, a new generation of MC receptor antagonists has been developed, which differ from its predecessors in a different mechanism of action, improved pharmacological properties and a more favorable safety profile. The review presents data on the pharmacokinetics and pharmacodynamics of the new nonsteroidal MC receptor antagonist finerenone, as well as the results of clinical studies obtained in assessing its effectiveness and safety in patients with CKD diabetic and nondiabetic origin.

Hereditary diseases of the kidneys and urinary tract are a common cause of chronic kidney disease in children. The progress of DNA analysis technologies has led to a significant increase in the efficiency of molecular genetic research in nephrology. The use of DNA diagnostics in pediatric nephrology makes it possible to establish a clinical and genetic diagnosis, the pathogenesis of hereditary kidney disease, determine a strategy for personalized treatment and management, and predict the patient’s health status in the future. Identification of the molecular defect underlying the development of the disease opens the way to the development of new targeted drugs and medical genetic counseling of families. The purpose of the review is to summarize the available information about the main areas of practical use of DNA diagnostics in pediatric nephrology.

BACKGROUND. Nephrotic syndrome (NS) develops with severe damage to the glomerular filter. The kidneys play a key role in the regulation of water-electrolyte homeostasis. However, the features of water-electrolyte disorders in glomerulopathy have not been studied enough. The aim of our study was to determine the main indicators of renal electrolyte transport in adult patients with NS. PATIENTS AND METHODS. 173 patients with glomerulopathy, 114 men and 81 women, were examined. The average age is 39.0±15.8 years. All of them were hospitalized during 2016-2019 years. A traditional nephrological clinical and laboratory examination was performed. Additionally, the indicators of electrolyte transport and osmotically active substances were calculated. RESULTS. Nephrotic syndrome (NS) was detected in 64 people (36.9 %). Patients with NS were characterized by lower levels of total protein, albumin, higher proteinuria, and dyslipidemia. The concentration of urea, potassium, calcium, inorganic phosphates and uric acid in the blood serum, as well as the eGFR value in the groups were comparable. Patients with NS had higher urinary clearance of sodium, potassium, and chlorine. In addition, they had a significant increase in the excreted fraction of sodium, chlorine and potassium. Hyponatremia was registered in 8.1 % and 13.1 % of patients, respectively, without and with NS. Hypocalcemia was observed in 14.5 % of patients without NS and in 22.9 % with NS. We have not revealed the relationship between the value of the excreted fraction of sodium, chlorine and potassium with the presence and severity of focal and diffuse interstitial fibrosis, depending on the nephrotic syndrome. Tubular atrophy increased the probability of an increase in the excreted fraction of sodium by 3 times, chlorine by 2.4 times. The median proportion of non-functioning glomeruli in patients with eGFR greater than 6 ml/min/1.73 m² and tubular atrophy was 3.0 [1.0; 5.0]. CONCLUSION. Renal electrolyte clearance is not associated with the presence of HC. The increase in the excretion of basic electrolytes is due to the severity of tubular atrophy. In patients with tubular atrophy, it is necessary not only to monitor the electrolyte composition of the blood, but also to monitor tubular functions. For this purpose, it is advisable to regularly determine the excreted sodium fraction.

In this article, the position of renal replacement therapy in the modern health care system is considered in detail, the experience of our country and foreign colleagues is presented. The main problems that arise during the practical implementation of this type of medical care and possible ways to overcome them are also touched upon. Diagnostic and therapeutic algorithms are presented that allow timely assistance to the population with chronic kidney disease, as well as to achieve an adequate level of provision and accessibility of renal replacement therapy. The latest registered information on the number of patients suffering from end-stage renal failure and receiving dialysis treatment, in particular in the Volgograd region, has been clarified.

BACKGROUND. Evaluation the level of citrulline (Cit) in the blood allows us to determine metabolic disorders in the proximal tubules of the kidneys. Previously, we showed that impaired metabolic function of the kidneys in hypertensive patients (AH) is expressed by an increase in the level of Cit. THE AIM was to determine diagnostically significant Cutoff value or exceeding Cit levels in the blood separately for men and women with hypertension. PATIENTS AND METHODS. We examined 115 hyperten sive patients with an estimated glomerular filtration rate ≥ 45 ml/min/1.73 m², included 44 men and 71 women aged 63 [56; 68] and 64 [53; 73] years, respectively. The comparison group included 30 older age group donors (11 men and 19 women). Determination of the levels of Cit, arginine (Arg) and others was carried out using high-performance liquid chromatography. RESULTS. Metabolic disorders: obesity – noted in 57 % of men and 50 % of women; and hypercholesterolemia in 30 and 33 % and hypertriglyceridemia in 37 and 29 % of patients, respectively. Metabolic dysfunction in the subgroups of men and women, according to Cit content, was expressed by an increase in its levels by an average of 32 and 29 %, respectively. ROC analysis determined the cutoff value for men > 49.1 μM Cit, p = 0.0023, which corresponds to 68 % sensitivity and 91 % specificity, and 46.3 μM (p = 0.0014) with 80 % sensitivity and specificity 63 % for women. CONCLUSION. A slight decrease in the metabolic functions of the kidneys affects Cit homeostasis, which has diagnostic value. According to the data obtained, renal metabolism ensures the content of Cit in the blood – not higher than 49.1 μM in men and women – 46.3 μM, before the onset of a violation of this metabolic function in patients with hypertension.

The article analyzes approaches to the formation of dialysis therapy membranes, on the basis of which a new promising method for creating and using composite and polymer materials for hemodialysis is proposed and experimentally tested. Special attention is paid to a significant increase in the working surface of semi-fiber synthetic polysulfone membranes by placing biocompatible boehmite nanoparticles on it. Before impregnation, the agglomerates of the nanoparticles were dispersed. At the same time, their size was reduced to individual particles in the delivery state with a size of ~ 30 nm. The crushing of agglomerates was facilitated by ultrasound (ultrasound). During dispersion, a surfactant was also used, the mechanism of action of which consisted in penetration between the agglomerate particles and a decrease in surface tension. After dispersion, the nanoparticles were located in nanocontainers of a mesh hydrogel formed when surfactants of polyethylene glycol enter distilled water. Boehmite was injected into polysulfone fibers using an ultrasonic capillary effect. When exposed to ultrasound and surfactants are used, the suspension with nanoparticles rises along the fiber channel and the particles are fixed on their inner surface. At the frequency of the ultrasonic generator used in operation, the liquid rises only a third of the height. Therefore, the further introduction of the suspension, the amount of which is calculated according to the geometric dimensions of the fibers, was carried out by instilling into the fibers from above using a syringe. The article shows the disadvantages of modern membranes and ways to eliminate them. One of these ways is to increase the inner surface of the dialyzer when using nanoparticles with a size of ~ 30 nm. An analysis of the size of blood elements showed that the nanoparticles we use are significantly smaller than them and can actually be used in hemodialysis technological processes.

Dietary considerations for salt (sodium chloride) in people with chronic kidney disease are based on multiple guidelines and suggest an intake of <90 mmol sodium per day, or <5 g sodium chloride per day. It is assumed that excess sodium intake contributes to the formation/maintenance of hypertension and edema syndrome. However, WHO data and cohort studies show that average salt intake is approximately twice the recommended level. In people with chronic kidney disease, a paradoxical situation often arises when, with recommended, but poorly followed, recommendations, 15-36 % of patients may develop hyponatremia. This is due to both the restriction of salt in the diet and the active use of loop diuretics, and recently SGLT-2is, GLP-1RAs against the background of RAASi and increasing age of the patient, which in itself is a risk factor for hyponatremia. In this regard, the possible clinical complications of hyponatremia increase significantly. The article addresses issues of physiology and pathophysiology of sodium metabolism, examines clinical situations and suggests careful treatment of significant restrictions on sodium chloride in the diet, keeping in mind the dietary cravings that develop during hyponatremia. Attention is drawn to the need to control serum sodium and be attentive to the dietary whims of patients.

The article presents a brief outline of the life and work of one of the outstanding Russian internists, the creator of the modern school of propaedeutics, academician Mikhail Dmitrievich Tushinsky.

BACKGROUND. Fabry disease is a rare hereditary x-linked liesomic accumulation disease, due to a decrease in the activity of α-galactosidase A, then glicosfinggolipids accumulates in different tissues of the body. The complexity of diagnosing of Fabry disease due to its rarity, as well as a variety of symptoms and syndromes, which can lead to an incorrect diagnosis. Early diagnosis of Fabry disease is crucial for the timely therapeutic intervention and a slowdown in the development of threatening organ damage... PATIENTS AND METHODS. The article presents a clinical observation of diagnosis of late-onset Fabry desiase in patient with hypertrophic cardiomyopathy, CKD C3a and stroke in patient’s history. he decrease in the activity of α-galactosidase A was assessed by determining the concentration of globotrializesfingosin (LySo-GB3) in dry stains of blood by tandem mass spectrometry. RESULTS. The first patient with Fabry's disease in the Republic of Karelia was found in the cardiology department. The patient was offered enzyme replacement therapy, and proband's relatives were offered family screening. At the time of publication, there was no decrease in the activity of α-galactsidase-A among 27 patients on the program hemodialysis. Screening still in progress. CONCLUSION. The results of the study confirm the rarity of the disease and a wide range of its manifestations. The clinical case illustrates the development of cardiovascular, cerebrovascular complications, the progression of renal failure in the Fabry disease.