Нефрология 

About: Нефрология is an academic journal published by Non-profit organization Nephrology. The journal publishes majorly in the area(s): Medicine & Internal medicine. It has an ISSN identifier of 1561-6274. Over the lifetime, 48 publications have been published receiving 10 citations. The journal is also known as: Nephrology & Nephrology (Saint-Petersburg).

Structural and functional intestinal barrier abnormalities and chronic kidney disease. Literature review. Part I

Abstract: The gut microbiota is an essential part of the human organism, which plays a crucial role in maintaining its homeostasis. Peaceful coexistence with trillions of microorganisms mainly depends on the normal functioning of cellular and extracellular components of the intestinal mucosa, often called the "intestinal barrier". This barrier protects the organism against pathogenic infections while and at the same time satisfying its requirements for digestion and absorption of nutrients. It is not surprising that structural and functional intestinal barrier abnormalities are involved in the pathogenesis of many diseases including various nephropathies. The pathogenetic interconnection between the intestine and the kidneys is bidirectional. On the one hand, uremia affects the microbiota composition and the integrity of the intestinal epithelium. On the other hand, uremic toxins translocation, formed as a result of abnormal microbial metabolism, from the intestine into circulation through the ultra-permeable barrier contributes to the progression of renal dysfunction. Furthermore, according to a number of researchers, dysbiosis and the leaky gut syndrome are considered as one of the possible causes of anemia, nutritional disorders, cardiovascular and many other complications, often diagnosed in patients with chronic renal disease. The first part of the review reflects modern data about normal intestinal barrier structure and physiology, as well as methods for studying the intestinal wall integrity and permeability. The significant role of microbiota in the regulation of the barrier properties of the intestinal mucous and epithelial layer is emphasizing. The main differences between the intestinal microflora of patients with nephropathies from healthy people are presented, possible causes of their occurrence are discussed.

Effect of COVID-19 on kidney function in patients with arterial hypertension grade 1-2 and CKD

Abstract: BACKGROUND. The presence and drug correction of arterial hypertension (AH) with inhibitors of the renin-angiotensin system (RAS), as well as chronic kidney disease (CKD) and its role in the regulation of RAS, can significantly affect the condition of a person with COVID-19. OBJECTIVE: to study the features of the functional state of the kidneys in patients with grade 1-2 hypertension who have fallen ill with COVID-19. PATIENTS AND METHODS. A subanalysis of patients with CKD, participants in the BIRCOV study (ARB, ACEi, DRi in COVID-19) is presented: 112 outpatient patients with grade 1-2 hypertension, 83 of whom had CKD. The participants were divided into groups receiving ACE inhibitors (group 1 – 39 %), ARBs (group 2 – 32 %), or a direct renin inhibitor (PIR) (group 3 – 29 %) as the main therapy of hypertension. The value of blood pressure, eGFR, albuminuria level were analyzed at the debut of COVID-19 and at 2, 4, 12, 24 weeks from the onset of the disease. RESULTS. In the first two weeks of COVID-19, there was a decrease in blood pressure with a gradual return to baseline values in patients of group 1 and group 3 (to a lesser extent). The use of ACE inhibitors in the treatment of hypertension increased the risk of withdrawal compared to PIR and ARBs due to COVID-19. In patients with CKD, higher values of mean blood pressure were obtained with similar dynamics. A synchronous decrease in eGFR and systolic blood pressure has been documented, more pronounced in patients with CKD, especially when taking aCEI. The decrease in eGFR correlated with the stage of CKD. With stable renal function in patients with CKD during the first 12 weeks of COVID-19, the urine albumin/creatinine ratio (UAC) increased without further normalization. By the second week of the disease, eGFR decreased with a reciprocal increase in the level of uric acid in the blood. The use of dexamethasone was accompanied by a decrease in eGFR in CKD stages 3b-4. CONCLUSION. When taking ACE inhibitors, the effect of lowering blood pressure was comparable to a double block of RAS: ACE inhibitors + ARBs.

Predicting the risk of fractures in kidney transplant recipients

Abstract: BACKGROUND. Chronic kidney disease leads to a significant increase in the risk of fractures, which increases even more after kidney transplantation. THE AIM. The goal of this study was to develop simple, accessible criteria for predicting the risk of fracture in patients with a functioning kidney transplant. PATIENTS AND METHODS. The prospective study included 131 kidney transplant recipients (men-55, women-76) (average age 39.7±11.7 years). The duration of follow-up was 40.7±21.2 months. Bone mineral density was assessed using dual-energy x-ray absorptiometry. To determine the prognostic significance of variables, we used stepwise regression (Cox model) analysis. p < 0.05 was considered statistically significant. RESULTS. During the follow-up period, fractures were registered in 47 patients (35.9 %). Fractures were detected more often in women (42 %) than in men (27.3 %). All patients with fractures had lower bone mineral density and longer-term renal replacement therapy. Stepwise multivariate regression analysis showed that the combination of bone mineral density scores of lumbar vertebra and duration of renal replacement therapy best predicts the overall fracture risk. Adding the other variables to the analysis did not increase significantly their predictive value. A comparative analysis of the cumulative proportion of males and females with fractures confirmed a greater susceptibility of female transplant recipients to fractures. CONCLUSIONS. The combination of bone mineral density scores of the lumbar vertebra with the duration of renal replacement therapy best predict the risk of fracture in patients with kidney transplants and can be used in the choice of prevention measures.

How to determine the prognosis of renal function in CKD?

Abstract: The presented material raises the most important question in practical nephrology – how to correctly assess kidney function to understand the prognosis and duration of the predialysis period in a particular patient with chronic kidney disease (CKD)? From the standpoint of onto- and phylogenesis, the hierarchy of kidney functions was assessed. It is noted that the existing approaches to such an assessment are convenient for practice, but do not sufficiently take into account individual characteristics and are devoid of a load component that can show kidney reserves. The authors focused on the functional renal reserve (FRR) and the possibility of its detection. The above technique with 0.45 % saline allows revealing the true functional capabilities of the kidneys and understanding the patient's capabilities in the pre-dialysis period. Conclusions are drawn about the convenient use of the KDIGO scale, a more individual approach when using the QxMD calculator, and the possibility of a personalized approach when assessing the FRR.

Structural and functional intestinal barrier abnormalities and chronic kidney disease. literature review. part ii

Abstract: The last few decades have been marked by significant progress in the investigation of the intestinal microbial-tissue complex and its role in the pathogenesis of a wide range of diseases. The presence of intestinal barrier dysfunction has also been confirmed in various nephropathies. Patients with chronic kidney disease (CKD) are characterized by specific alterations of the qualitative and quantitative composition of the gut microbiota. These changes contribute to an increase in the fermentation of food proteins into uremic toxins, such as p-cresyl sulfate, indoxyl sulfate and trimethylaminoxide, disorders of immune tolerance mechanisms of the mucous membrane, disorganization of intestinal epithelium tight junctions, which inevitably leads to an increase of transepithelial permeability. Translocation of bacteria and microbial metabolism products from the intestinal lumen into the systemic circulation is responsible for systemic inflammation, which is currently considered as one of the leading causes of the CKD progression and related complications. However, the exact mechanisms of gut-kidney interaction remain poorly understood. The second part of the review gives a detailed description of the structural and functional disorders of the intestinal muco-epithelial barrier identified in various nephropathies. The mechanisms of uremia-induced intestinal epithelial disruption are discussed, as well as the current therapeutic strategies that may attenuate consequences of intestinal barrier dysfunction in patients with CKD.