Recent technological advances have significantly enhanced our understanding of the role microbial communities play in the human body. The gut microbiota, one of the most diverse microbiomes, consists of over 35,000 bacterial species and 10 million genes, leading researchers to consider it as an additional organ. This whiles relatively stable within each individual highly influenced by exogenous and endogenous factors. Collectively, the gut microbiota functions as a "second genome", profoundly impacting the host’s metabolic pathways and regulating the body’s complex homeostatic balance.

Research into the "microbe–host" interaction, both in health and disease, has garnered worldwide scientific. In chronic kidney disease (CKD), the gut microbiota undergoes significant changes, and growing evidences suggests that dysbiosis plays a crucial role in the progression of renal failure. Key pathological process, such as the production of gut-derived uremic toxins, decreased synthesis of short–chain fatty acids, altered intestinal pH, compromised intestinal barrier function, and heightened systemic inflammation, are all linked the intestinal microbiota. However, relationship between these changes and the pathogenesis and progression of kidney disease requires further investigation. Advances in microbiome research, including metagenomic and metatranscriptomic analyses, alongside proteomic, metabolomics, and immunomic studies, have greatly expanded our understanding of microbiomal community structure and functions. These technologies, coupled with mechanistic experiments in model systems, have deepened our knowledge of how the microbiome influences metabolism. Current research aims to explore the bidirectional relationship between the microbiota and the host, identifying potential interventions that could help restore a mutualistic relationship.

Severe kidney injury in ANCA-associated vasculitis remains a major challenge for healthcare practitioners due to the difficulty in defining the term and the limitations in the evidence base associated with the exclusion of the most severely ill patients from majority of clinical trial protocols. The ACR/VF, EULAR, and KDIGO recommendations intended to answer the questions regarding the management of this patient’s population, but some recommendations on both initial and supportive therapy, provided be the expert panels, differ, which increase the number of treatment options, but also leads to the uncertainty of the expected effect of the treatment. Kidney biopsy plays an important role in identifying patients with a favorable and unfavorable kidney prognosis. Timely histological assessment is necessary not only to confirm the diagnosis, but also to decide whether to intensify therapy if active changes are detected, or, conversely, to discontinue immunosuppressive treatment and switch to renal replacement therapy if chromic changes dominate and the extrarenal manifestations are quiescent. Several scoring systems for assessing kidney damage and risks in the in ANCA-associated vasculitis were proposed during the last decade. Glucocorticoid’s dosing and the choice between cyclophosphamide and rituximab for the initial therapy remains controversial, and the most controversial issue to date remain the indications for the plasma exchange usage. New treatment options for ANCA-associated nephritis, such as the usage of complementblocking therapy are likely to improve the prognosis for the patients with severe renal damage, taking into account the maximum effect on renal function restoration in this particular category.

Aims: to study the characteristics of preeclampsia (PE) in women with chronic kidney disease (CKD) compared to PE in the general population.

Method: a prospective observational study analyzed the course of PE in 24 women with a previously established diagnosis of CKD (Group 1) and 39 women in the general population (Group 2) without a complicating somatic history. In patients with CKD with a known pregestational creatinine level, the physiological response of the kidneys to pregnancy was assessed, defined as a decrease in serum creatinine by more than 10% in the first trimester. The angiogenic ratio (sFlt-1/PLGF) was studied in 13 patients with CKD.

Results: the two groups did not differ in age or parity. In the first group, 16 patients had CKD stage 1-2, 5 had CKD 3A, and one patient each had CKD 3B, 4 and 5 (the later receiving hemodialysis). Nineteen (79%) of women with CKD had hypertension, proteinuria (PU), renal impairment or a combination of these factors before conception. Only 3 out of 16 patients had a physiological renal response. Early PE developed in 58.3% of patients with CKD compared to 35.3% in second group (p = 0.082). The duration of PE inversely correlated with the stage of CKD (r = -0.630; p = 0.001). As pregnancy progressed in patients with CKD, PU increased, reaching nephrotic level in 54% of women by the time of PE. HELLP syndrome or isolated hematological signs of TMA were noted in 8 patients in the general population group, and in 1 in the CKD group. The average sFlt-1/PLGF value in patients with early stages of CKD (n = 9) was 81.0±24.0, with late stages (n = 4) it was 14±8.

Conclusion: the study identified the features of PE in CKD: early onset, increased PU reaching nephrotic level in half of the cases by the time PE is diagnosed, and the absence of a histological renal response to pregnancy in the 1st trimester. The lack of changes in the angiogenic coefficient in women with PE and late-stage CKD requires further study in a larger group of patients.

The purpose of this study was a comparative analysis of the characteristics of the course and outcomes of COVID-19 in HD patients at different stages of the pandemic, focusing on the of the use of immunomodulatory therapy.

Materials and methods. The retrospective study included 897 HD patients with COVID-19 (mean age 60.7 years, M 58.5%) who were hospitalized at Moscow City Hospital № 52. Group 1 (n=720) consisted of patients infected between the end of March 2020 and April 2021, group 2 (n=177) included patients hospitalized in May-December 2021. Each of group was divided into 2 subgroups based on treatment approaches. Subgroup 1a (n=231) included patients of the initial period of the pandemic who did not receive adequate immunomodulatory therapy, while Subgroup 1b (n=489) included patients of the late stage, were treated with IL-6 receptor blockers and corticosteroids. In group 2, 108 patients in Subgroup 2a received similar therapy, while 69 patients in Subgroup 2b were treated with neutralizing monoclonal antibodies in the early stages of the disease.

Results. Mortality rates in Group 1 and Group 2 was 20.1% and 14.7%, respectively (p<0.09). The incidence of unfavorable outcome was highest in Subgroup 1a and lowest in Subgroup 2b (31.2% vs 5.8%, p<0.01). Mortality in Subgroups 1b and 2a was comparable (14.9% and 20.4%), despite more severe initial lung damage according to CT data in Subgroup 2a. In these patients, immunomodulators was more frequently combined with therapeutic plasma exchange (TPE). Independent risk factors for an unfavorable outcome were the progression of pulmonary pathology, with the transformation of stages CT 1-2 to CT 3-4, and a high comorbidity index.

Conclusions. The use of immunomodulatory drugs imprtoved the effectiveness of COVID-19 treatment in patients with CKD5D. In severe cases, the most favorable outcomes were achieved with a combination of immunobiological drugs, corticosteroids, and TPE. An even more significant reduction in mortality was observed following the introduction of neutralizing monoclonal antibodies into clinical practice. Independent predictors of unfavorable outcome of COVID-19 in HD patients were a high comorbidity index and the progression of CT 1-2 into CT 3-4.

Aim. To determine the structure of kidney diseases in 17-year-old adolescents before their transition to the adult healthcare system using the 2019 KDIGO.

Methods. This single-center, cross-sectional descriptive study analysed a 10-year regional register of 893 adolescents hospitalized in the V.P. Sitnikova nephrology department at Voronezh Regional Children’s Clinical Hospital between 2013 and 2022. Kidney functions assessed using the CKiDbed (2009) and CKDEPI (2009) equations. Statistical significance was defined as a p<0.05.

Results. Over 70% of all hospitalizations were related attributed renal tubulo-interstitial diseases (N10- N16), congenital malformations of the urinary system (Q60-Q64), and glomerular diseases (N00-N08). The distribution of kidney conditions included CKD (36.6%), AKD without AKI (14.9%), AKD combined with CKD (8.5%), AKI (0.4%), AKI combined with CKD (1.3%), and no kidney disease. CKD was more prevalent in males (69.5%, vs 45.3% in females, p<0.001), while AKD was more common in females (38.0% vs 15.1% in males). GFR calculation discrepancies between CKiDbed and CKD-EPI equations led to changes in GFR categories and CKD/AKD stages 55.8% of adolescents, with the largest median discrepancy in males (37 ml/min/1.73 m2).

Conclusions. the study classified kidney diseases in 17-year-old, revealing gender differences and highlighting the impact of varying GFR calculation methods of disease staging. The findings emphasized the need for consistent GFR assessment approaches across pediatric and young adult healthcare.

Aim: to assess the dynamics of laboratory parameters (total calcium, inorganic phosphorus, albumin, and alkaline phosphatase levels) and parathyroid hormone (PTH) concentrations after administrating local injections of vitamin D receptor activators into the parathyroid glands of patients with secondary hyperparathyroidism in chronic kidney disease. The intial PTH concentration ranged from 300 to 600 pg/ml. This range was chosen to explore a more active strategy for managing the disease at its early stages and preventing the induction and progression of cardiovascular complications associated with secondary hyperparathyroidism.

Methods: the study included 48 patients diagnosed with end-stage of chronic kidney disease, who were treated in the nephrology and dialysis department. The main group consisted of 34 patients who received two consecutive injections of a vitamin D receptor activator (Paricalcitol) into the most enlarged and technically accessible parathyroid gland under ultrasound guidance. The control group included 14 patients who continued with conservative treatment due to technical infeasibility of performing the injections. Effectiveness was assessed by comparing laboratory parameters before the intervention and six months after the injections in the main group, and among patients continuing standard medical therapy for secondary hyperparathyroidism.

Results: the results showed a statistically significant reduction in parathyroid hormone levels after 3 and 6 months of treatment. In the control group, which continued to receive standard drug therapy, PTH and blood phosphate levels continued to rise. No undesirable effects or complications, such as hypocalcemia, bleeding, allergic reactions, and recurrent laryngeal nerve paralysis, were not observed throughout the observation period.

Conclusion: this research confirms the efficacy of local injections of vitamin D receptor activators (Paricalcitol) in reducing PTH levels without significant complications or changes in calcium levels. This method could be employed to correct and prevent secondary hyperparathyroidism complications in early stages among patients with end-stage chronic kidney disease, offering a safer and more effective treatment option.