[The role of mineralocorticoid receptors hyperactivation in the development of cardiorenal complications in patients with diabetes mellitus, perspective of the selective nonsteroidal mineralocorticoid receptors antagonist's treatment: A review].

The renin-angiotensin-aldosterone system (RAAS) activation plays a key role in the chronic kidney disease (CKD) progression and in the cardiovascular complications (CVC) development in patients with diabetes mellitus (DM). RAAS blockers alone are not sufficient to prevent CVC and CVC progression. RAAS upregulation in CKD associated with DM triggers the mineralocorticoid receptors (MCR) hyperactivation which results in fibrosis and inflammation in the heart and kidneys. This review presents the current data about the variety of MCR hyperactivation manifestations, as well as about of multiplicity of MCR hyperactivation ways in DM. The efficacy and safety of finerenone, a new MCR nonsteroidal selective antagonist, are discussed.

[State-of-the-art paradigm of corticosteroid therapy for immune-mediated inflammatory kidney diseases].

Since 1950's corticosteroids (CS) have remained the cornerstone of immunosuppressive therapy for immune-mediated kidney diseases. However multiple adverse events, associated with the prolonged CS therapy, became the basis for the development of novel treatment approaches. Current evidence supports the implementation of the steroid-sparing regimens for the treatment of different types of glomerulonephritis. Randomised controlled trial PEXIVAS demonstrated the efficacy and safety of early steroid tapering, starting from the second week of therapy, in patients with ANCA-associated vasculitis with kidney involvement. Several trials showed the efficacy of oral prednisolone 0.3-0.5 mg/kg/daily as a part of multitarget therapy for severe proliferative lupus nephritis. A combination of calcineurin inhibitors and low-dose CS are effective for remission induction in membranous nephropathy, as well as the steroid-free rituximab regimen for the patients with moderate risk of disease progression. Medium dose CS showed promising effect in patients with IgA-nephropathy. Long-term high dose CS remain the standard-of-care for the treatment of minimal change disease and focal segmental glomerulosclerosis, however patients with steroid-dependent and relapsing disease tacrolimus and rituximab can help to achieve steroid-sparing effect. The role of CS pulse-therapy is currently debated, nevertheless it remains a compulsory treatment in several conditions. Thus, overall trend is directed towards the minimization of the maximal doses of CS and/or treatment duration. However, to implement this approach morphological verification of the diagnosis and personalized assessment of the potential risk and benefit are required.

[Clinical significance of the determination of antibodies to thrombospondin type 1 containing domain 7A (THSD7A) in membranous nephropathy].

BACKGROUND: Membranous nephropathy (MN) is an immunocomplex glomerular disease, which is the most common cause of nephrotic syndrome in adults. Numerous studies have established that autoantibodies against the target podocyte autoantigens, including the thrombospondin type 1 domain containing 7A (THSD7A), play a leading role in the development of idiopathic MN. AIM: To evaluate the prevalence of anti-THSD7A autoantibodies (anti-THSD7A AB) in a group of Russian patients with MN. MATERIALS AND METHODS: Serum titers of anti-THSD7A AB were tested in 61 patients with biopsy-proven MN and 12 healthy controls. RESULTS: The prevalence of anti-THSD7A AB was not differing significantly in patients with MN and in the control group (110.9 [71.63; 210.62] and 159.25 [125.64; 231.97] pg/ml, respectively; p=0.111). When comparing subgroups of anti-PLA2R-negative patients and patients who did not receive immunosuppressive therapy with the control group, there were also no statistically significant differences in the Anti-THSD7A AB levels (p>0.05). In the MN group, 1 (1.6%) patient was anti-THSD7A-positive: a 60-year-old man with anti-PLA2R-negative MN and the presence of hormonally inactive adenomas of both adrenal glands and colon polyps (villous adenoma with focal moderate dysplasia, tubulo-villous and tubular adenoma with focal moderate severe dysplasia). CONCLUSION: THSD7-associated MN is a rare variant of MN and is usually detected in PLA2R-negative patients. Screening for malignancies in THSD7A-positive MN patients is proposed.

[Frailty and chronic kidney disease - the real problem of modern nephrology: A review].

The article deals with the syndrome of frailty or senile asthenia in patients with chronic kidney disease. The questions of prevalence, diagnosis, pathogenesis of this syndrome and its clinical consequences in chronic kidney disease are discussed.

[Lupus nephritis in the XXI century].

Lupus nephritis (LN) is the most common organ lesion in systemic lupus erythematosus (SLE), developing in 4050% of patients. Due to immunosuppressive therapy, the survival of patients with SLE has increased significantly over the past 50 years, and the proportion of severe kidney damage in the death structure has decreased. However, LN relapses and complications of immunosuppression, accelerated atherogenesis, concomitant diseases lead to the accumulation of organ damage and an increased risk of death. The article consideres the place of kidney damage in the SLE, the risk factors for LN development, the main renal histopathological changes, it identifies a number of issues that need to be addressed to optimize treatment and improve LN long-term outcomes, including, the revision of pathogenetic therapy regimens with restriction of glucocorticosteroids and prescribing drugs with steroid-sparing activity, the integration of new drugs for LN treatment, wider use of modern nephroprotection capabilities.

[Modern view on the complement system role in membranous nephropathy].

Membranous nephropathy (MN), an immune-mediated glomerular disease, is the most common cause of adult nephrotic syndrome. In MN, proteinuria is developed by podocyte damage due to the complement system activation in response to the subepithelial deposition of immune complexes containing various auto- and exogenous antigens. Membrane-attacking complex (MAC) is the terminal product of any complement pathways activation (classical, lectin or alternative) and plays the leading role in the complement-mediated podocytic damage. Thus far, the main pathway of complement activation leading to the formation of MAC in MN has not been established. The review highlights current evidence of various complement pathways activation in the development of MN, as well as recently established new molecular mechanisms of complement-mediated podocyte damage.

[Kidney damage caused by lead exposure: historical aspects].

The article presents an historical analysis of publications devoted lead intoxication to kidney damage developing during contact with lead. It is shown that one of the manifestations of occupational intoxication with this metal can be toxic nephropathy.

[The Rehberg-Tareev test in assessing the glomerular filtration rate].

The history of glomerular filtration rate assessment is presented, an important step of which was the glomerular filtration rate evaluation by the endogenous creatinine clearance (known as the RehbergTareev test). The article highlights the diagnostic value of the RehbergTareev test and its place among modern methods for assessing glomerular filtration rate.

[Kidney injury associated with antitumor therapy: focus on the adverse events of modern immuno-oncological drugs].

Immune checkpoint inhibitors (ICIs), including cytotoxic T-lymphocyte associated antigen 4 (CTLA-4) and programmed death protein 1 (PD-1) or its ligand (PD-L1), are a new generation of immuno-oncological drugs that to date have demonstrated efficacy in a number of malignancies. The mechanism of ICT inhibitors action consist in the potentiation of the immune response by eliminating the tumor cells inhibitory effect on the T-lymphocytes activation. However, excessive immune system activation can cause the development of a special class of immune-related adverse events (irAEs) involved a wide variety of organs and systems, including the kidneys. Despite the fact that immuno-mediated kidney injury caused by ICI therapy develops quite rarely, it can be serious and determine the patient's prognosis, which necessitates early diagnosis and timely start of treatment. In this regard, awareness of the manifestations of ICI-associated renal irAEs is particularly relevant not only for oncologists and for nephrologists, but for doctors of other specialties. In this review, we elucidated the main variants of immuno-mediated kidney injury caused by ICI therapy, discussed possible predictors and mechanisms of their development, and considers the general principles of diagnosis and management of patients according to the severity of irAEs.

[Monoclonal gammopathy of renal significance: consensus of hematologists and nephrologists of Russia on the establishment of nosology, diagnostic approach and rationale for clone specific treatment].

Monoclonal gammopathy of renal significance (MGRS) is a new nosology in modern nephrology and oncohematology. MGRS is defined as kidney injury due to nephrotoxic monoclonal immunoglobulin produced by the B-cell line clone which does not reach the hematological criteria for specific treatment initiation. Monoclonal proteins pathological effects on kidney parenchyma result in irreversible decline of kidney function till the end stage renal disease that in line with the position of International Consensus of hematologists and nephrologists determinates critical necessity for clone specific treatment in patients with MGRS despite the absence of hematological indications for treatment initiation. Main challenge of MGRS in Russian Federation is an inaccessibility of an in-time diagnostic and appropriate treatment for the great majority of patients due to the following reasons: 1) limited knowledge about the MGRS among hematologists and nephrologists; 2) lack of necessary diagnostic resources in most health-care facilities; 3) lack of approved clinical recommendations and medical economic standards for treatment of this pathological entity. Consensus document comprises the opinion of experts leading nephrologists and hematologists of Russian Federation on the problem of MGRS including the incoherence in nosology classification, diagnostics approach and rationale for clone specific treatment. Consensus document is based on conclusions and agreements reached during the conference of leading nephrologists and hematologists of Russia which was held in the framework of symposia Plasma cell dyscrasias and lymphoproliferative diseases: modern approaches to therapy, 1516 of March 2019, Pavlov First Saint Petersburg State Medical University. The present Consensus is intended to define the principal practical steps to resolve the problem of MGRS in Russian Federation that are summarized as final clauses.

[The balance of proinflammatory cytokines and Treg cells in chronic glomerulonephritis].

Chronic glomerulonephritis (CGN) is a disease with a steadily progressing course, which is based on inflammation with the activation of immune cells. The severity of the inflammatory reaction in the kidney tissue is determined by the balance of locally pro-inflammatory factors and protective mechanisms, which include anti-inflammatory cytokines and T-regulatory lymphocytes (Treg). The study of processes that can modulate the severity of inflammation in the kidney is of particular interest for understanding the basic patterns of CGN progression. AIM: To determine the clinical significance of the Th17, Th1, and Treg cytokines in urine to assess the activity and progression of chronic glomerulonephritis with nephrotic syndrome (NS). MATERIALS AND METHODS: The study included 98 patients with CGN 37 women and 61 men. Patients were divided into two groups according to the degree of CGN activity. Group I consisted of 51 patients with NS. In 21 subjects, a decrease in GFR60 ml/min was revealed. Group II included 47 patients with proteinuria from 1 to 3 g/day without NS. GFR60 ml/min/1.73 m2 was observed in 26 patients. A kidney biopsy was performed in 65 patients and the hystological diagnosis was verified: 20 had mesangioproliferative GN, 16 had membranous nephropathy, 18 had focal segmental glomerulosclerosis, and 11 had membranoproliferative GN. The control group consisted of 15 healthy people. The levels of IL-6, IL-10, IL-17, tumor necrosis factor a (TNF-a) in the urine were determined using enzyme-linked immunosorbent assay. The number of FoxP3-positive cells in the inflammatory interstitial infiltrate of the cortical layer was determined in 39 patients (in a biopsy sample in a 1.5 mm2 area). RESULTS: In group of patients with CGN, there was an increase in the levels of Th17, Th1, and Treg cytokines in urine TNF-a and IL-10 compared with healthy individuals. An increase in the levels of IL-6 in the urine of patients with high clinical activity of CGN (with NS and renal dysfunction) was more pronounced than in patients with NS and normal renal function. There was a decrease in the number of Treg cells in the interstitium of the kidney and a decrease in the production of anti-inflammatory IL-10 in CGN patients with NS, compared with patients without NS. The most pronounced changes in the cytokine profile were observed in patients with FSGS with an increase in pro-inflammatory cytokines and a decrease in Treg in the kidney tissue/anti-inflammatory IL-10 in the urine. CONCLUSION: An imbalance of cytokines characterized by an increased levels of pro-inflammatory IL-17, IL-6, TNF-a, and a reduced levels of anti-inflammatory IL-10 and T-regulatory cells in the kidney tissue is noted in patients with NS, especially with FSGS. Imbalance of cytokines reflects the high activity of CGN and the risk of the progression of the disease.

[Changes in metabolic parameters and glomerular filtration rate in patients with morbid obesity after bariatric surgery].

AIM: To study the effect of weight loss in the short term after bariatric surgery (BO) on metabolic parameters and glomerular filtration rate (GFR) in patients with morbid obesity. MATERIALS AND METHODS: We studied 40 adult (over 18 years) patients with morbid obesity who underwent bariatric surgery. Metabolic indices and calculated GFR according to the CKD-EPI formula in patients before and after bariatric surgery were compared. RESULTS: In the whole group of operated patients, the average body mass index (BMI) after surgery decreased from 45.8 to 30.5 kg/m2. In 11 (92%) patients with impaired carbohydrate metabolism, remission of diabetes mellitus was achieved and sugar-lowering drugs were canceled. In patients with baseline GFR90 ml/min/1.73 m2 after surgery, there is a tendency towards a decrease in GFR, probably due to a decrease in hyperfiltration. In patients with baseline GFR90 ml/min/1.73 m2 after surgery, a statistically significant increase in the level of GFR was noted. The greater metabolic efficacy of combined operations (mini-gastric bypass, biliopancreatic diversion) in relation to the correction of carbohydrate and fat metabolism was revealed. CONCLUSION: Obesity is a modifiable risk factor for decreased kidney function and the progression of chronic kidney disease. Bariatric surgery is an effective treatment for morbid obesity. The study proved the positive effect of weight loss after BO on renal function, including by improving the course of diseases associated with obesity.

[Modern view on treatment of membranous nephropathy].

Membranous nephropathy (MN) is the most common cause of nephrotic syndrome in adults. Since the moment of animal model creation and the recognition of podocytes damage as a key mechanism of MN development, the identification of antigens, first of all the phospholipase A2 receptor (PLA2R), and the development of methods of PLA2R autoantibodies detection and its monitoring opened a new era in the idiopathic MN (iMN) diagnosis, treatment and prognosis evaluation. MN continues to be actively studied in the new millennium, since a number of aspects of its pathogenesis still need to be clarified, and there is still no clear opinion on the iMN treatment optimal approach. Comprehensive clinical and serological assessment of patients with iMN can be the key to individual choice of treatment protocols. In patients with aPLA2R-positive iMN, the predictor of disease remission is the aPLA2R titer decrease or aPLA2R disappearance in the blood serum, and disease relapse is associated with the aPLA2R appearance ore increase of aPLA2R titer in the circulation. Studies which were conducted by today (GEMRITUX, MENTOR, STARMEN, NICE, etc.) confirmed the acceptable safety profile and effectiveness of iMN therapy by anti-CD20 monoclonal antibodies (rituximab): more than half of of iMN patients had remission of nephrotic syndrome or proteinuria decrease, remissions in anti-CD20 monoclonal antibodies treated patients were longer compared to traditional therapy. The obtained data allows us to consider rituximab and anti-CD20 antibody therapy of a new generation not only as an alternative to the more toxic treatment with cyclophosphane and calcineurin inhibitors, but as an independent promising direction of therapy for patients with IMN, which completely changes the paradigm of treatment of this glomerulopathy.

[Modern approaches to conservative therapy of polycystic kidney disease].

Polycystic kidney disease (PKD) is a genetically determined pathological process associated with the formation and growth of cysts originating from the epithelial cells of the tubules and/or collecting tubes. PBP is represented by two main types - autosomal dominant (ADPKD) and autosomal recessive PKD (ARPKD), which are different diseases. The main causes of ADPKD are mutations of the PKD1 and PKD2 genes, which encode the formation of polycystin-1 and polycystin-2 proteins. ARPKD-linked mutation in the gene PKHD1, leads to total absence or defective synthesis of receptor protein primary cilia - fibrocystin. There are relationships between the structural and functional defects in the primary cilia and PBP. Mechanisms of cysts formation and growth include a) mutations of polycystines genes located on the cilia; b) increased activity of renal intracellular cAMP; c) vasopressin V2 receptors activation; d) violation of the tubular epithelium polarity (translocation of Na,K-ATPasa from basolateral to apical membrane); e) increased mTOR activity in epithelial cells lining renal cyst. The most promising directions of ADPKD therapy are blockade of vasopressin V2 receptors activation, inhibition of mTOR signaling pathways and reduction of intracellular cAMP level. The review presents clinical studies that assessed the effectiveness of named drugs in ADPKD.

The role of podocytes dysfunction in chronic glomerulonephritis progression.

In the review, the mechanisms of podocytes damage underlying the development of proteinuria and progression of glomerulosclerosis in chronic glomerulonephritis are discussed in detail. The results of experimental and clinical studies are presented. Under the different immune and non-immune factors the podocytes form a stereotyped response to damage consisting in the reorganization of the actin cytoskeleton, foot process effacement, the detachment of podocytes from the glomerular basement membrane, and the appearance of specific podocyte proteins and whole cells (podocyturia) in the urine. Massive podocyturia in a limited proliferative capacity of podocytes leads to reduce their total count in the glomerulus (podocytopenia) and the development of glomerulosclerosis. The authors describe the line of markers of the podocyte injury and invasive and non-invasive methods of their assessment. In addition, the relationship of podocyturia level with proteinuria and renal dysfunction are discussed, the prospects of assessment the podocyte proteins in urine for assessing of glomerular damage severity and glomerulosclerosis risk are examined.

Nephrological aspects of surgical weight correction in morbid obesity.

Obesity, including morbid obesity, is a growing worldwide problem. The adverse effect of obesity on the kidneys is associated with the development of comorbid conditions, such as insulin resistance (IR), metabolic syndrome (MS), diabetes mellitus (DM), arterial hypertension (AH), which are the recognized risk factors of chronic kidney disease (СKD). Obesity also causes direct kidney damage with the development of non-immune focal segmental glomerulosclerosis. The leading pathophysiological mechanisms of kidney damage in obesity are intrarenal hemodynamic disorders with the formation of hyperfiltration and damaging effects of adipokines produced by adipose tissue. Bariatric surgery (BS) has taken a leading position in the treatment of morbid obesity, demonstrating its effectiveness not only in long-term weight loss, but also in the correction of IR, MS, DM, AH. Nephroprotective effect of significant and persistent weight loss is caused by the elimination of hyperfiltration and damaging effect of adipokines. Results of the observational studies of the immediate and long-term effects of BS have demonstrated positive renal outcomes, in particular, the decrease in albuminuria/proteinuria, the improvement or stabilization of glomerular filtration rate, the delay of end-stage renal failure development; surgical correction of body weight in dialysis patients with morbid obesity lets them realize subsequent kidney transplantation. Large, randomized prospective studies with a longer follow-up are needed; analysis of the long-term renal consequences of BS in obesity patients with pre-existing renal impairment, including dialysis patients, is required; stratification of the BS risk of renal complications (acute kidney damage, nephrolithiasis, nephrocalcinosis) and effective strategy for managing these risks need to be developed.

Genetic determinants of the development and course of membranous nephropathy.

Membranous nephropathy (MN) is one of the most common causes of nephrotic syndrome in adults and is classified as either primary (idiopatic) or secondary MN according to underlying etiology (the later result from some known disease such as systemic autoimmune diseases, infections, malignancies, drugs, etc). In recent years, phospholipase A2 receptor 1 (PLA2R) and thrombospondin type-1 domain-containing 7A (THSD7A) were identified as two major podocytic antigens involved in the pathogenesis of idiopatic MN (IMN). And the discovery of circulating antibodies specific for these target antigens has transformed the diagnostic workup and significally improved management of IMN. However why do such antibodies develop is not conclusively established. The role of underlying genetic factors is discussed. The review presents the results of recent studies, that have shown significant associations of specific genetic factors (particularly human leucocyte antigen class II and PLA2R1 genes) with IMN.

Risk factors for diastolic left ventricular myocardial dysfunction in patients with chronic kidney disease.

AIM: To examine the frequency and risk factors for the development of diastolic dysfunction (DD) of the left ventricle (LV) of the heart in patients with chronic kidney disease (CKD). MATERIALS AND METHODS: The study included 225 patients with stage I-CKD of non-diabetic etiology (median age 47.0 years, 50.2% of women). Depending on the degree of decrease in the glomerular filtration rate (GFR), all patients were divided into 3 groups. Group 1 (n=70) consisted of patients with GFR 89-45 ml / min / 1.73 m2, group 2 (n=120) - patients with GFR 44-15 ml / min / 1.73 m2, group 3 (n=35) - patients with GFR <15 mL / min / 1.73 m2. The control group includes persons without CKD. All patients underwent general clinical examination and transthoracic echocardiography; in 86 patients the level of cystatin C in the blood serum was determined. RESULTS: Hypertrophy of the left ventricle (LVH) of the heart was detected in 87 (38.7%) of 225 patients with CKD. Hypertrophic type (type I) of myocardial DD is diagnosed in 90 (41.4%) of 225 patients with CKD. The incidence of myocardial left ventricular dysfunction of the 1st type increased with a decrease in GFR, amounting to 30, 40 and 60% in groups 1, 2 and 3, respectively. The systolic function of the left ventricular myocardium was preserved. Patients with DD were older, they had a higher body mass index (BMI), a more pronounced decrease in GFR, a higher level of fibrinogen. They were more likely to have LVH. The level of cystatin C as the kidney function worsened, but when comparing the mean levels of cystatin C in patients with the presence / absence of DD in the groups isolated depending on the stage of CKD, no statistically significant differences were found. According to the multivariate analysis, the independent predictor of DD was the age (odds ratio 1.106, 95% confidence interval 1.051-1.157, p=0.00001). CONCLUSION: DD of the myocardium of the LV is detected on average in 40% of patients with CKD, the frequency of its development increases with the progression of renal dysfunction. The development of DD is influenced by traditional factors of cardiovascular risk (age, BMI), as well as the decline in GFR and closely related structural remodeling of LV myocardium.

[Late-onset rheumatoid arthritis in a patient with successfully treated IgA nephropathy]. / Pozdnii debiut revmatoidnogo artrita u patsienta s uspeshno lechennoi IgA-nefropatiei.

The paper describes a rare clinical case of rheumatoid arthritis (RA) that developed in a patient 9 years after diagnosing IgA nephropathy. Kidney disease was characterized by a stable course with moderate urinary syndrome, hypertension, and reduced renal function. Immunosuppressive therapy using glucocorticosteroids and then mycophenolic acid led to remission of nephritis and recovery of renal function. However, the absence of nephritis activity and discontinuation of immunosuppressants was responsible for articular syndrome. The diagnosis of RA is based on its characteristic radiological patterns and immunological characteristics after ruling out a number of systemic diseases and infections. The common pathogenetic components of IgA nephropathy and RA, including the role of rheumatoid factor IgA, are discussed.

[MicroRNAs in chronic glomerulonephritis: Promising biomarkers for diagnosis and prognosis estimation]. / MikroRNK pri khronicheskom glomerulonefrite: perspektivnye biomarkery dlia diagnostiki i otsenki prognoza.

The review presents the results of recent experimental and clinical studies of the expression pattern of a number of miRNAs, a recently described new class of noncoding RNAS that are able to regulate the posttranscriptional expression of genes and thus to modulate several physiological and pathological processes in different morphological types of chronic glomerulonephritis. It considers the possibilities of using miRNAs as new biomarkers to diagnose the disease, to predict its course and a response to therapy.