The review considers the universal mechanisms of systemic edema and the features of its formation in patients with nephritic and nephrotic syndromes, congestive heart failure, and decompensated cirrhosis. Normally, renal excretion of sodium regulates extracellular fluid volume. Regulation of sodium excretion is achieved by intrinsic mechanisms, which affect glomerular filtration and tubular reabsorption. The pathophysiology of sodium retention has been intensively discussed for several decades. However, underfill and overfill theories are not able to explain the onset of edema. Strong evidence is presented for the role of the endothelial glycocalyx as a determinant of the transcapillary fluid movement. The results of experimental studies demonstrated an increase in sodium reabsorption in cortical tubes in nephrotic and nephritic syndromes due to activation of Na/K ATPase and epithelial sodium channels. But the factor that directly stimulates the sodium channels and transporters remains unidentified. One of the reasons for the sodium retention is a decrease of effective blood volume, which occurs in congestive heart failure and decompensated cirrhosis. Understanding the pathophysiology of systemic edema is important for the choice of the optimal therapy and for the prevention of edema.

The role, significance, the localization of renal stem cells (RSC) are discussed. It is expected that the role of RSC can act parietal epithelial cells of Bowman's capsule of glomeruli. At the same time important to determine the RSC is the identification of immunophenotype CD24, CD133, PDX. There are indications of the presence of RSC with PDX positive and negative status, which determines their differentiation in podocytes. In renal tubular epithelium RSC can be transformed into mature epithelial cells by dedifferentiation of localized or specific groups. So far, not fully resolved the issue of the presence of RSC among epithelial cells of the convoluted tubules. It is known that epithelial cells (EC) of tubules are highly specialized, differentiated epithelial cells, cubic or cylindrical, are polar apical-basal location. Phenotypically as podocytes possess low mitotic activity, but in case of damage they can express protein cyclin D1, which is an indicator of G1-phase of the mitotic cycle. We discuss several sources of cells capable of differentiating into EC. EC themselves participate in the regeneration process, among the presence of single RSC EC, extrarenal role of stem cells (a pool of cell proliferation). The most popular model is the development of differentiated EC, they pass stage of dedifferentiation. EC dedifferentiation involves a transition from an epithelial to mesenchymal state (epithelial-mesenchymal transition, EMT) and return to the cell cycle with the development EC (mesenchymal-epithelial transition MET). However, it remains unclear whether among EC produced at MET appear only mature form of cells or some of them can retain the properties of stem. Identify different types of RSC opens a new stage in the study of biological phenomena of regeneration of various cellular components of the nephron, which will determine the development of new medicines, prevent the development of renal fibrosis and renal failure.

Аpparent mineralocorticoid excess syndrome (AMEs) is autosomal recessive severe hypertension associated with low serum renin activity and aldosterone level, hypokalemia, metabolic alkalosis, hypercalciuria and nephrocalcinosis. This disease refers to the group of monogenic forms of hypertension and is associated with mutations in the HSD11B2 gene, encoding the type 2 11β-hydroxysteroid dehydrogenase that participates in cortisol metabolism. Here, we present a clinical case of a child with typical AMEs characteristics. Sequencing of all exons of the HSD11B2 gene responsible for AMEs revealed novel homozygous mutation c.991G>A (p.A331T) in exon 5. Stage-by-stage hypotensive therapy with monotherapy and combinations of calcium channel blockers, angiotensin II receptor blockers, thiazide diuretics, and the use of antagonists of mineralocorticoid receptors, potassium-sparing diuretics was insufficient for the correction of hypertension in the child. Only the appointment of low doses of steroids - dexamethasone, aimed to reducing the endogenous production of cortisol, made it possible to achieve a persistent hypotensive effect and to normalize the electrolyte and acid-base equilibrium in the patient’s blood.

Background: anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is the most common cause of rapidly progressing glomerulonephritis (RPGN). Its prognosis has improved, however long-term patient morbidity and mortality still remain relatively high due to toxic effects of immunosuppressive treatment. Therefore, a search for optimal predictors of long-term outcome of this disease is of particular importance. Aim: to evaluate the short- and long-term outcomes of AAV-RPGN and their dependence the histopathologic classification. Materials and Methods: 115 biopsy-proven AAV-RPGN patients, aged 56±14.3 years (40% older than 60), were included in the retrospective study. The serum creatinine level by the time of presentation was 570 [380; 830] µmol/L. According to histopathology, the patients were divided into 4 groups: focal (22 pts), crescentic (34 pts), sclerotic (33 pts), and mixed (29 pts) RPGN. Induction therapy was carried out with methylprednisolone and cyclophosphamide IV pulses followed by oral prednisolone. Rituximab was used in 21 patients. Maintenance therapy was carried out with prednisolone and azathioprine or MMF. Results: improvement was observed in 77% of patients: 100% in group with focal, 80% in mixed, 57% in crescentic, and 52% in sclerotic RPGN. Five-years patient survival rate was 67.7%. It decreased to 38% in the group of patients older than 60 years versus 80% in the younger group. Five-years renal survival was 59% and was closely associated with the categories of glomerular lesions: 89% in group with focal RPGN, 78% in mixed RPGN, 56% in crescentic, and 34% in sclerotic RPGN (p<0.05). Conclusion: our results show that histopathologic category of glomerular lesions in AAV-RPGN has predictive value for renal outcome.

Aim: to determine the prevalence of deficiency and insufficiency of vitamin D (vitD), secondary hyperparathyroidism and calcium-phosphorus disorders in children with chronic kidney disease stages 4-5 (CKD 4-5), on hemodialysis (HD), on peritoneal dialysis (PD), after kidney transplantation (Tx) and to assess changes of these parameters on the background of treatment with cholecalciferol (D3) and with phosphate-binding agents containing calcium carbonate and D3 (Ca-D3). Methods: serum levels of calcium, phosphorus, total 25-hydroxyvitamin D (25(OH)D), intact parathyroid hormone (PTH) were determined in 106 children (age 12.4±4.8 years): Tx 53, PD 18, HD 23, CKD 4-5 without dialysis 12. If 25(OH)D in blood was <20 ng/ml - deficiency, if 20-29 ng/ml - insufficiency. Results: vitamin D deficiency and insufficiency of revealed in 86.8% Tx patients, 88.9% PD patients, 91.3% HD patients, and 75% of CKD 4-5 patients. The lowest values of 25(OH)D was detected in the PD group. Secondary hyperparathyroidism was found in 1.9% Tx patients, 44.4% PD patients, 47.8% HD patients, and 50% of CKD 4-5 patients. Seasonal variations of 25(OH)D levels and a decrease in its levels with time were found in Tx patients. Intake Ca-D3 for at least a year led to a normalization of phosphorus in 45.5% on PD patients with developing hypercalcemia in 31.8% of them and decreasing PTH levels below the target in 76.2% cases. 75% of children had high or toxic blood levels of 25(OH)D if a daily intake of D3 was 8000 ME. Conclusions: deficiency and insufficiency of vit D is widely prevalent in children on PD or HD, with CKD 4-5 and after Tx. It requires treatment and subsequent maintenance therapy with vitD.

Aim: the study was performed to optimize the planning of the methods of renal replacement therapy (RRT) in a cancer hospital. Materials and methods: the medical records of 187 patients treated in Irkutsk Regional Oncology Center and 687 renal replacement therapy procedures due to renal failure were analyzed. Results: in the retrospective analysis, some differences in the structure of acute renal injury were revealed in patients required renal replacement therapy, compared with those in non-oncological patients. It has been determined that the greatest proportion of renal pathology falls on postrenal acute renal injury caused by cases of long-term undiagnosed cancer of pelvic organs which are often in Russia. The decisive indicators for RRT were: the severity of uremic intoxication, decompensated metabolic acidosis, uncorrected hyperkalemia etc. The RRT procedures were both intermittent and continuous character; the intermittent hemodialysis has some advantage. Continuous procedures (CRRT) are used primarily in patients with unstable hemodynamic parameters. In 7 patients, renal replacement therapy was performed due to extrarenal indications. Conclusion: in order to optimize the planning of RRT in the cancer hospital, it is necessary to take into account that intermittent hemodialysis is more often than continuous methods of RRT (65% vs. 33.71%) with only 1.29% for the remaining RRT methods (SCUF and other).

Introduction: the function of the peritoneal membrane can deteriorate over time. Peritonitis and glucose overload may be the important reasons. Contemporary functional tests are able to evaluate the fluid transport characteristics. Its alteration can predict submesotelial fibrosis progression. Methods: the cross-sectional study in 46 unselected patients from one center (female - 54%, age 59±16) with PD vintage of 35±34 months is the start of prospective observational study. The peritoneal membrane function was assessed with double mini-PET (two 1-hour exchange with 4.25% and 1.5% glucose). The glucose load was evaluated as the total mass of glucose flooded in cavity according PD-regimen per month and totally. Results: the total ultrafiltration was 562±199 ml including free water transport (FWT) - 171±68 ml and water transport through small pores 391±161 ml. The osmotic conductance to glucose (OCG) was 5.38±2.88 μl/min/mmHg. The longer PD time was linked with lower FWT (-16 ml/year) and OCG (-0.233 μl/min/mmHg/year) and with higher MTAC-Cr (+1.2 ml/min/year). FWT was inversely linked with the total glucose load, but for monthly load such association was significant only for subgroups without history of peritonitis or with monthly load higher than median (2.72 kg/mo). In multivariate regression models FWT was predicted by total glucose load (-4.8 mL/[10 kg], p=0,002) (but not monthly load) for whole group. In the subgroup with monthly load higher than median the dialysis duration (but not total glucose load) was inversely linked with FWT (-24 ml/1 year). Conclusion: the discrepancy in fluid and solute transport parameters under impact of different factors require more longitudinal studies to improve the prognosis evaluation for UFF and submesothelial fibrosis.

Residual renal function (RRF) in patients on renal replacement therapy (RRT) with hemodialysis plays an important positive role in the survival prognosis. Many studies confirm the relationship between the RRF and the improvement of quality of life on RRT, both with hemodialysis and peritoneal dialysis. However, it poses the following question: is it possible to reduce the frequency and/or duration of procedures in patients with a significant RRF? In most guidelines on hemodialysis, it is recommended to adjust the dialysis dose for patients with a glomerular filtration rate of more than 2 ml/min/1.73 m2. However, parameters of effective dialysis duration are not defined. The twice-a-week modality of hemodialysis is the most studied in this respect. The twice-a-week hemodialysis is rarely used in Europe and the USA, where it is mainly associated with patient's will to limit the time spent for the procedures and transportation. In a number of developing countries, it is associated with economic constraints. Studies comparing the efficacy of twice-weekly and standard three times a week hemodialysis in patients depending on the RRF, revealed a better effect of twice-a-week hemodialysis on outcomes such as mortality, number of hospitalizations, and health-related quality of life in the first year of treatment. The aim of this review is to identify the validity of twice-a-week hemodialysis and its impact on mortality, the number of hospitalizations and the health-related quality of life in patients with RRF. We considered the studies in this field and the applicability of their results in daily practice.

The optimal dialysis regimen remains unresolved: empirically established in early 1960 triweekly schedule was the best compromise between that year’s dialysis ability to remove uremic toxins and availability of dialysis treatment and is not exclusive one. The increase in the number of sessions per week is justified in some cases for the improvement of the efficiency and tolerability, while the decrease in the number can be forced by limited resources (in general or local, due long distance to dialysis center). Another possible reason is a perceived intention to slow down the decreasing of residual kidney function as well as to improve the quality of life of the frail patients without significant worsening of survival or other patient-centered outcomes, especially since the patients and dialysis providers demonstrated the impressive difference in evaluation of various outcomes significance. We discussed the conditions for safely implementation of hemodialysis with increasing frequency for preservation of residual renal function. Such practice in peritoneal dialysis are justified and well established in integrative care system for patients with chronic kidney failure.

Pregnancy in patients with terminal renal failure receiving renal replacement therapy by hemodialysis is associated with high risks of complications at all stages of its development. Here we describe a case of qualified observation and treatment of a 39 years old patient with terminal renal failure and planned pregnancy, starting with pregravid preparation. Dialysis therapy promoted the normalization of the most important functions of the women’s body, including reproductive. At the time of the initiation of pregravid preparation, the duration of renal replacement therapy was twenty-two years. Conception occurred on the background of pregravid preparation. In the process of observation, adequate correction of the dialysis and drug therapy was carried out. This clinical case describes some complications that occur at the twelfth week of the pregnancy, such as anemia, cholestasis. Considering the high risk of premature birth from 18 weeks of gestation, the patient's maternal mode was limited to the bed-rest by being in a specialized gynecological hospital. Continuation of conservative therapy of pregnancy at the period of 23-24 weeks in the obstetric-gynecological clinic allowed the prolongation of the bearing of the fetus and the choice of the optimal method of delivery - cesarean section. The appointment of glucocorticoids at 23d and 25th weeks of pregnancy provided prevention of respiratory distress syndrome in the fetus. As a result, the mother and child were discharged in a good condition.