The editorial touches upon the problem of the possible impact of COVID-19 on CKD patients, mediated by the forced reorganization of the health care system in a whole, the redistribution of its resources in the context of the COVID-19 pandemic. Lack of regular outpatient monitoring, delayed diagnosis and therapy in patients with kidney dysfunction are factors of adverse clinical outcomes - accelerated disease progression, ESKD development and the need for KRT, life-threatening complications, reduced quality of life and survival. The data of a pooled analysis of the impact of the pandemic on specialized renal care and its availability in a number of regions of the Northwest Federal District of Russia and the Moscow Region are presented: a fall in hospital admissions, outpatient consultations and a decrease in the use of hospital beds (on average, by 37 %, 40 % and 32 %, respectively). Principles and conditions of the functioning of health systems associated in the COVID-19 pandemic have been discussed. The main approaches to maintaining the standard level of renal patients care have been formulated, aimed at preventing an unfavorable patient-oriented CKD outcomes.

Diabetic nephropathy (DNP) develops in 30-40 % of patients with type 1 and 2 diabetes mellitus (DM). It is the leading cause of the end-stage renal disease (ESRD) in the world. The proportion of people with DNP in the structure of patients receiving treatment with the replacement of renal function reaches 40 %. DNP is associated with a significant worsening of the cardiovascular prognosis. Over the past 5 years, significant changes have taken place in the approaches to the treatment of persons with DNP (including both reno- and cardioprotection). They concern, first of all, the emergence of new antihyperglycemic drugs, which have shown in serious randomized controlled trials (RCTs) beneficial effects on prognosis in diabetes in general and in DNP, in particular. Changes in views on treatment tactics for DNI have already been recorded in a number of serious international and domestic regulatory documents, the discussion of the main positions of which was the purpose of this literature review. The review is devoted to main therapeutic approaches in diabetic nephropathy according to current home and international Guidelines with focusing on randomized controlling investigations results on using renin-angiotensin-aldosterone-system blockers and antithrombotic, hypolipidemic, hypoglycemic agents different classes.

Lipoprotein(a) [Lp(a)] is a subclass of lipoproteins consisting of a cholesterol-rich low-density lipoprotein (LDL) particle with a single apolipoprotein B100 molecule covalently bound (via a disulfide bridge) to a unique hydrophilic high-glycosylated protein called apolipoprotein a [apo(a)]. To date, there is sufficient evidence to consider an increase Lp(a) level as a causal and independent risk factor for cardiovascular disease and calcifying aortic valve stenosis. Plasma concentration of Lp(a) can vary in a wide range, which is mainly determined by genetic factors. Up to 30 % of the world's population has an elevated Lp(a) level, but this category of lipid disorders has not been currently receiving adequate attention. Determining the Lp(a) plasma concentrations is not included in the standard lipid profile, so a significant number of individuals with hyperlipoproteinemia(a) who could potentially benefit from treatment remain undiagnosed. Certain significant obstacles are still associated with the lack of standardized assay for measuring Lp(a) concentrations and a consensus on its optimal levels in blood plasma. Although some limited but statistically significant data suggest a possible benefit of lipoprotein(a) lowering on cardiovascular outcomes, no specific recommendations were made for the management of that dyslipidemia in the latest guidelines. Plasma Lp(a) levels reflect a balance of Lp(a) synthesis, which occurs in the liver, and catabolism, which is thought to involve the kidney. Lp(a) concentration begins already to increase in the earliest stages of chronic kidney disease, and patients with nephrotic syndrome have a four-fold elevated Lp(a) in comparison to healthy individuals. However, it remains unclear if elevated Lp(a) levels affect cardiovascular risk in patients with kidney diseases. This article summarizes the main data regarding the relationship between Lp(a) content, impaired renal function, and an increased risk of adverse cardiovascular events.

Chronic kidney disease (CKD) is a chronic catabolic condition accompanied by sarcopenia, manifested by decreased muscle mass, strength, and endurance. As defined by the European Working Group on Sarcopenia in the Elderly (EWGSOP), sar-copenia is a progressive and generalized skeletal muscle disorder that is associated with an increased likelihood of adverse outcomes including falls, fractures, physical disability, and mortality. Its prevalence in patients with CKD, according to various sources, varies from 3.9 to 65.5 %, depending on gender, age, and stage of the disease. It develops as a result of an imbalance between protein degradation and synthesis. The development of muscle atrophy is associated with oxidative stress, inflammation, and leads to the progression of atherosclerosis. This scientific review contains current information on the problem of sar-copenia in patients with CKD, its prevalence, the molecular basis of pathogenesis, as well as its contribution to cardiovascular risk and mortality from cardiovascular diseases in the discussed group.

Background. Primary hyperparathyroidism (PHPT) is an endocrine disease, due to the formation of excess parathyroid hormone secretion and a disturbance of phosphorus-calcium metabolism. PHPT is associated with reduced renal function and related increased mortality, therefore renal function impairment defined as a glomerular filtration rate (GFR) less than 60 mL/ min/1.73 m² is considered as an indication for surgical treatment. Some patients with PHPT have secondary cardio-renal syndrome (type 5), which is characterized by the presence of combined renal and cardiac pathology. THE AIM: Evaluate the GFR in patients with mild and symptomatic PHPT and its changes after parathyroidectomy and on medical treatment.

Patients and methods: A cross-sectional comparative and prospective study was conducted on 100 patients with confirmed PHPT. A clinical and laboratory examination was performed at 6, 12, and/or 24 months and included an assessment of the PHPT complications as well as expression of cardio-renal syndrome according to the selected management tactics. Changes in GFR were evaluated in 29 patients after surgical treatment and in 27 patients on conservative management. Glomerular filtration rate was calculated by the Modification of Diet in Renal Disease Study (MDRD) formula. The chronic kidney disease (CKD) stage was estimated accordingly to current recommendations.

Results: We included 100 patients (10 men and 90 women) with PHPT: 33 with mild and 67 with symptomatic PHPT. The median age was 57 years [51;61]. Mean GFR was 84,1 [73,3; 97,9] ml/ min/1,73 m². Prevalence of CKD 3-4 in patients with PHPT was recorded at 11 %. Patient management tactics were determined in accordance with international recommendations. In the long-term period after surgery, we observed the decrease of GFR in patients with mild form within the limits of CKD 1-2 (p=0,013, W-test). No significant changes in GFR were noted during medical management and monitoring. Summary, the cardio-renal syndrome (CKD of any stage and cardiovascular pathology) was revealed in 26 % of patients. Arterial hypertension was registered in 40 %.

Conclusions: We found a high frequency of renal function impairment in patients with PHPT, including patients with a mild form of the disease. We did not observe any significant improvement in renal filtration function, after surgical treatment and remission of PHPT. The safety of conservative tactics has been confirmed. The high frequency of cardiovascular pathology in patients with PHPT is beyond doubt and requires prospective studies in the larger cohorts of patients.

The aim. Evaluation of renal function variations during different year seasons in men under 60 years old within acute and subacute phases of myocardial infarction (MI) to prevent dysfunction and enhance forecasting.

Patients and methods. Examination and treatment results analyses of 412 men with MI under 60 y.o. for the period of 2000-2015 who had 30-59 mL/ min/1,73 m² calculated glomerular filtration rate (GFR, CKD-EPI 2009, modification 2011) at the end of the third week from the disease onset (61 patients) and more than 60 mL/min/1,73 m² respective-ly (315 patients) had been conducted. Renal function changes were assessed during treatment in the first 48 hours and at the end of the third week from the MI onset in patients groups that were combined aligning to the climatic seasons of the year founded on average daily air tem-perature of St. Petersburg, Russia changes. Variations of renal dysfunction (RD) development simulation in different year seasons corresponding to the end of the third week of the disease were conducted with the use of classification trees methodology.

Results. Reliable evidence of creatinine and GFR level changes depending on the seasonal variances have been identified for the early periods of the MI development. An ef-fective prognostic algorithm with efficiency as high as 62 % for patients risk groups separation among men under 60 y.o. with MI potent to RD development at the end of the third week of disease was created.

Conclusions. Higher creatinine levels and low levels of GFR in men under 60 y.o. with MI are being observed in spring and winter. The risk group for RD development at the end of the MI subacute period represents smokers in summer and autumn; chronic heart failure history patients in winter; patients with diastolic arterial blood pressure in the MI acute period of 90 mm Hg and more in spring. Prescription of medicinal products with nephroprotective features starting from the first hours of MI development in this group of pa-tients is beneficial.

Background. Decreased thyroid function is common in patients with chronic kidney disease. Under conditions of hypothyroidism, there is significant changes in lipid metabolism, nitrogen excretion function of the kidneys. THE AIM. To study the parameters of the functional state of the thyroid gland in patients with various stages of chronic kidney disease.

Patients and methods. A one-stage cross-sectional study of patients with glomerulopathies without clinically significant diseases of the cardiovascular system with preserved EF (> 55 % according to Simpson) from April 2019 to March 2020 was carried out. The study included 270 patients. To identify subclinical hypothyroidism (SH), the TSH level was determined. Patients were divided into groups according to TSH level: low TSH, normal TSH, and subclinical hypothyroidism. In patients, the indicators of biochemical blood analysis, data from a complex laboratory functional examination of the kidneys were assessed.

Results. The detection rate of SH in patients with different stages of CKD was 17.56 %. Patients with SH were significantly older than the group of patients with normal TSH levels (p=0.002). In the group of patients with subclinical hypothyroidism, anti-TPO antibodies were detected only in 9.6 % of patients. A correlation was found between GFR and free T3 in patients with 3B and 4 stages of CKD (r=0.3, p<0.05). In the group of patients with subclinical hypothyroidism, there was a decrease in total protein and albumin, an increase in daily proteinuria, a decrease in total calcium, increased inorganic phosphorus, chlorine, decreased renal transport of uric acid.

Conclusion. Increased TSH levels are associated with advanced stages of CKD. The increase in TSH levels in patients with CKD is not associated with female sex and older age. In most patients with glomerulopathies, an increase in TSH levels is not an outcome of autoimmune thyroiditis. SH in CKD patients is associated with severe impairment of renal nitrogen excretion function, protein, and electrolyte metabolism.

Idiopathic nephrotic syndrome is the most common childhood glomerulopathy. Despite modern advances in medicine, idiopathic NS is still a big problem, this is due to the fact that the mechanisms of pathogenesis are not fully understood, and the lack of unified approaches to drug therapy are the main obstacles to improving care for children. Approximately 20% of patients with nephrotic syndrome are resistant to standard glucocorticosteroid therapy, the so-called steroid-resistant nephrotic syndrome. In recent years, the issue of the role of the multidrug resistance gene ABCB1 in the formation of steroid resistance in children with primary nephrotic syndrome has been discussed. This article presents our own data on the study of ABCB1 gene expression in children with idiopathic nephrotic syndrome. A change in ABCB1 gene expression was demonstrated depending on the response to steroid therapy. Thus, ABCB1 gene expression is higher in patients with steroid-resistant nephrotic syndrome than in patients who responded to steroid therapy. At the same time, there are significant differences in ABCB1 expression between SZNS and SNNS. In clinical practice, patients with steroid-dependent nephrotic syndrome have relapses of the disease against the background of withdrawal of prednisolone, which is most likely due to the rapid elimination of prednisolone and further requires a revision of the prednisolone reduction scheme. The data obtained indicate the need for a personal approach to the management of patients with idiopathic nephrotic syndrome, taking into account the molecular genetic characteristics.

Background. Urinary tract infections are the most common nephrological diseases in girls. Currently, there is a need to develop comprehensive interdisciplinary approaches to the examination of patients with vulvovaginitis against the background of pre-school urinary tract infection.

The aim: to study the characteristics of comorbid symptoms of vulvovaginitis in girls of pre-school age suffering from urinary tract infections. PATIENTS AND METHODS. A prospective controlled study was conducted in 107 girls aged 3-6 years, including: group 1 (n=45) - patients with vulvovaginitis against a background of recurrent urinary tract infection; group 2 (n=32) - patients with an isolated form of vulvovaginitis; group 3(n=30) - girls of 1, 2 health groups. A specialized gynecological examination was performed. Statistical processing was performed using the application program "SPSS Statistics 17.0 for Windows".

Results. Revealed that patients with concomitant vulvovaginitis compared to patients with isolated vulvovaginitis, often marked by painful urination, discomfort in the genital area, serous (35.7 %) and mucopurulent (55,6 %) vaginal discharge, petechial rash, anatomical (prolapse of the urethra, close proximity of the meatus to the entrance of the vagina) and inflammatory changes (edema, hyperemia) in the region of the urethra, high frequency fringed structure of the hymen (p=0,12). Diffuse hyperemia in the vulva area was more often observed in patients with isolated vulvovaginitis.

Conclusions. Patients with vulvovaginitis and recurrent recurrent urinary tract infection have a burdened social and biological history. In dispensary management, an interdisciplinary approach is required, taking into account the identified medical and social risk factors.

In November 2017, the Kidney Disease: Improving Global Outcomes (KDIGO) initiative brought a diverse panel of experts in glomerular diseases together to discuss the 2012 KDIGO glomerulonephritis guideline in the context of new developments and insights that had occurred over the years since its publication. During this KDIGO Controversies Conference on Glomerular Diseases, the group examined data on disease pathogenesis, biomarkers, and treatments to identify areas of consensus and areas of controversy. This report summarizes the discussions on primary podocytopathies, lupus nephritis, anti-neutrophil cytoplasmic antibody-associated nephritis, complement mediated kidney diseases, and monoclonal gammopathies of renal significance.