The report of the Russian Kidney Replacement Therapy Registry presents data on the national and federal district levels for the period from 2016 to 2020. Statistical data on the incidence and prevalence of end stage kidney disease in adult patients on hemodialysis, peritoneal dialysis, and those with functioning kidney graft are provided.

The report of the Russian Kidney Replacement Therapy (KRT) Registry presents data on the national and federal district levels for the period from 2015 to 2019 is presented. The current publication contains information about the treatment of end-stage kidney disease pediatric patients on hemodialysis, peritoneal dialysis, and functioning kidney graft in Russia, as well as a comparison with European countries.

The Kidney Disease: Improving Global Outcomes (KDIGO) 2021 Clinical Practice Guideline for the Management of Glomerular Diseases is an update to the KDIGO 2012 guideline on the topic. The aim is to assist clinicians caring for individuals with glomerular disease, both adults and children. The scope includes various glomerular diseases, including IgA nephropathy (IgAN) and IgA vasculitis (IgAV), membranous nephropathy, nephrotic syndrome in children, minimal change disease (MCD), focal segmental glomerulosclerosis (FSGS), infection-related glomerulonephritis (GN), antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis, lupus nephritis, and anti-glomerular basement membrane (anti-GBM) antibody GN. In addition, this guideline will be the first to address the subtype of complement-mediated diseases. Each chapter follows the same format providing guidance related to diagnosis, prognosis, treatment, and special situations. The goal of the guideline is to generate a useful resource for clinicians and patients by providing actionable recommendations with valuable infographics based on a rigorous formal systematic literature review. Another aim is to propose research recommendations for areas where there are gaps in knowledge. The guideline targets a broad audience of clinicians treating glomerular disease while being mindful of implications for policy and cost. Development of this guideline update followed an explicit process of evidence review. Treatment approaches and guideline recommendations are based on systematic reviews and evidence synthesis of relevant studies, and appraisal of the quality of the evidence and the strength of recommendations followed the “Grading of Recommendations Assessment, Development, and Evaluation” (GRADE) approach. Limitations of the evidence are discussed, with areas of future research also presented.

Objective: to evaluate the changes in biomarkers of acute kidney injury (AKI) in obstetric patients with atypical hemolytic uremic syndrome (aHUS) and HELLP syndrome. Materials and methods: the study included 6 patients with HELLP syndrome and 3 patients with aHUS. All patients were assessed for the presence of "classic" signs of AKI - AKI was diagnosed according to the presence of at least one of the criteria listed by Prakash J. et al.: (1) sudden increase in serum creatinine >90 µmol/L, (2) oliguria/anuria, and (3) need for dialysis. In addition to routine clinical and laboratory examinations, all patients were examined for levels of retinol-binding protein, α1-microglobulin, cystatin C, podocalyxin, NGAL, and kidney injury molecule-1 (KIM-1) in urine. Results: AKI was diagnosed by standard methods in all patients with aHUS and in half of patients with HELLP syndrome, while biomarkers were elevated in absolutely all patients. The minimal number of simultaneously elevated biomarkers was three. All patients had an increase in the level of α1-microglobulin and retinol-binding protein, 67% of patients had an increase in the level of cystatin C, 44% of KIM-1, and 33% of NGAL, which indicates a significant damage to the renal tubular apparatus. The marked increase in the level of podocalyxin in all patients confirms the presence of glomerulopathy in all cases of TMA, even in the absence of "classic" symptoms of AKI. Conclusions: signs of AKI are observed in all patients with signs of TMA, however, in half of patients with HELLP syndrome, kidney damage was subclinical. An increase in the level of various AKI markers characterizes complex damage to various parts of the nephron, including the distal tubules. We suggest that the use of urinary biomarkers may be useful for early diagnosis and timely treatment of AKI.

The aim of the study was to evaluate the efficacy and safety of COVID-19 vaccine prophylaxis with vaccines produced in Russia in kidney transplant recipients. Materials and methods: the study included 144 renal transplant recipients (RTR) 51.9±11.3 years old (male 66.2%). In most cases (95.8%), the Gam-COVID-Vac vaccine was used for immunization. Patients were divided into 2 groups depending on the scope of the examination: in group 1 (n=67) IgG antibodies to the receptor-binding domain of SARS-COV-2 S-protein (IgGs) were determined before and after vaccination; in group 2 (n=77) only after vaccination. The duration of follow-up after the start of immunization was 66.8±28.3 days. The effectiveness of vaccination was assessed by seroconversion in initially seronegative RTR; in patients with COVID-19 in the anamnesis - by the degree of increase in the level of antibody IgGs (>25%) after immunization. Results: 14 out of 144 (9.7%) RTR (7 patients in each group) underwent COVID-19 within 35 days after the administration of the first dose of the vaccine and were excluded from the analysis. Initially seronegative patients in group 1 failed to achieve seroconversion in 76.9% of cases, and in group 2 in 59.3% of RTR. Among seropositive patients after vaccination in both groups, the level of IgGs was significantly lower in RTR, who initially did not have IgGs, compared with patients with COVID-19 in the anamnesis: 47.5 (24.8; 133.3) BAU/ml versus 501.0 (395.4; 501.0) BAU/ml, respectively, p <0.001 in group 1 and 63.0 (41.0; 108.0) BAU/ml versus 501.0 (455.5;501.0) BAU/ml, respectively, p <0.001 in group 2. The level of IgGs antibodies in RTR group 1, who had previously COVID-19 increased from 110.5 (25.3; 244.0) BAU/ml to 501.0 (395.4; 501.0) BAU/ml (p <0.001), respectively, before and after vaccination. In general, in the long term after immunization, 7 RTR were infected with SARS-CoV-2, 6 of them were seronegative, and 1 patient with seroconversion had a low level of IgGs antibodies (32 BAU/ml); 1 patient died due to ARDS. Immunization did not affect the function of the kidney graft. Conclusions: obtained results indicate a low frequency of humoral response when using standard vaccination protocols against COVID-19 in RPT, which necessitates modification of their immunization regimens with an analysis of not only the effectiveness and safety but also the duration of protection of its enhanced variants.

Apolipoprotein E (APOE) gene encoding apolipoprotein E is located on chromosome 19 (19q13.2). APOE is the main component of chylomicrons and lipoproteins of low and very low density, eliminated by the liver. APOE gene abnormalities lead to impairment of binding of lipoproteins to hepatocyte receptors, which cause the delay or blockade of the lipoproteins clearance and, as a result, increase of their plasma concentration [1]. Three isoforms (alleles/exons) of the APOE gene include E2, E3 and E4. Exon E3 is the most frequent (75%) and "neutral". Exon E2 is the rarest (5%). Above mentioned impairment of lipoprotein receptor binding associated mainly with exons E2 and E4 variants. Patients with homozygous allelic variants - E2/E2, E4/E4 - experience most severe manifestations [2,3]. Heterozygous allelic variants of the APOE gene with different combinations of exons E2, E3, E4 lead to lipid metabolism disorders with various severity and prognosis [4, 5]. Kidney tissue damage in patients with the APOE gene breakage is a rare condition, merging a group of nephropathies of different clinical and histological severity. The main feature of this nephropahies is the accumulation of lipoproteins in the kidney tissue, primarily in the glomeruli [6]. Patient G., 28-year-old. Family history is significant for stroke, diabetes, and malignancies in grandparents; patient’s father had morbid obesity and died early, and younger sister, 24-year-old, developed proteinuria up to 1.5 g/24 h at age of 18 years. Our patient was discovered with proteinuria in 2013. In 2018, his proteinuria increased up to 2.0 g/L, and was accompanied by moderate azotemia. Kidney biopsy was performed in 2019. At the time of biopsy, his BP was 130/90 mm Hg, and his body mass index was normal, serum creatinine was 370 μmol/L, and proteinuria was 16.0 g/24h, without edema or biochemical criteria of nephrotic syndrome. Histological examination revealed metabolic nephropathy with marked glomerulomegaly and extensive secondary segmental glomerulosclerosis, with mesangial and endocapillary lipid accumulation, with moderate tubulointerstitial fibrosis and moderate arteriolosclerosis ( Fig. 1). In addition, clinically quiescent moderate mesangial IgA-deposits were identified ( Fig. 2). Based on the pathology findings, genetic testing for the APOE gene was strongly recommended, and the APOE-E3/E4 gene polymorphism was confirmed. By February 2021, chronic kidney disease progressed to the Stage 5 with serum creatinine 736 µmol/L and eGFR 5 mL/min. Initiation of hemodialysis was advised, however the patient refused this option of kidney replacement therapy. March 2022 kidney transplantation from the relative donor (patient’s mother) was performed. The APOE gene has not been investigated in the mother or other family members. Thus, we report here the case, belonging to a rare group of genetically determined lipid metabolism disorders, associated with a breakage in the APOE gene. This metabolic disorder lead to chronic kidney disease, which progressed towards kidney failure and required kidney replacement therapy. Informed patient consent for publication of clinical information and images was obtained.

Brief information about the disease pathogenesis presented in the introduction to the previous case. Patient E., 27-year-old. Family history is remarkable for myocardial infarctions - patient’s father had recurrent myocardial infarctions and died at the age of 52 years. Our patient developed obesity and arterial hypertension with BP up to 170/110 mm Hg at the age of 13 years. In 2020 he had proteinuria, and his serum creatinine was 600 μmol/L; same year kidney biopsy was performed. At the time of biopsy he had morbid obesity (body weight 160 kg), and newly diagnosed diabetes mellitus, his BP was 140/90 mm Hg, total cholesterol 12.0 mmol/L, fasting glucose 6.3 mmol/L, serum creatinine 635 µmol/L, and proteinuria 17.0 g/24h without edema or biochemical criteria of nephrotic syndrome. Pathology examination revealed metabolic nephropathy with extensive secondary sub-globular glomerulosclerosis, with massive conglomerates of foamy cells ( Fig. 1), with lipid microthrombi in the glomerular capillaries ( Fig. 2), marked chronicity with extensive complete glomerulosclerosis, severe tubulointerstitial fibrosis and severe arteriolosclerosis. Based on the pathology findings, genetic testing for the APOE gene was strongly recommended, and the APOE-E3/E4 gene polymorphism was confirmed. June 2021 his serum creatinine was 640 µmol/L and eGFR 9 ml/min; and he was diagnosed with chronic kidney disease Stage 5. August 2021 he was started on kidney replacement therapy with peritoneal dialysis December 2021 kidney transplantation from relative donor (patient’s mother) was performed. The APOE gene has not been investigated in the mother or other family members. Thus, we report another case from a rare group of genetically determined lipid metabolism disorders, associated with a breakage in the APOE gene. The peculiarity of the case is the infrequent possibility to visualize lipid microthrombi in the glomerular capillaries. The disease progressed to the chronic kidney disease Stage 5, demanding kidney replacement therapy. In both cases, graft function prognosis is most important. For the described patient’s category, the issues of the recurrence of the metabolic nephropathy in the graft remains almost unstudied due to the rarity of the condition, which does not allow drawing valid conclusions so far. However, a very important general conclusion for all categories of kidney transplant recipients has been drawn by two independent groups of investigators: along with other well-established prognostic risk factors, such as donor’s age and the number of acute rejection episodes, the recipient’s APOE gene E3/E4 polymorphism is an independent negative prognostic factor and predictor of chronic transplant nephropathy [1, 2]. Informed patient consent for publication of clinical information and images was obtained.

One of the reasons for the development of nephrotic syndrome (NS) in patients with systemic lupus erythematosus (SLE) is lupus podocytopathy (LP), a rare variant of kidney damage in SLE that accounts for only 0.6-1.5% of cases. The diagnosis of lupus podocytopathy in clinical practice remains difficult. Despite the accumulated information about this form of kidney damage in SLE, the lack of generally accepted diagnostic criteria and low awareness of practicing physicians, both rheumatologists and nephrologists, leads to errors in the management of patients with this complication. The clinical observation presented demonstrates this problem: unrecognized LP caused the withdrawal of the diagnosis of SLE, which led to the abolition of maintenance therapy, followed by the development of a relapse of the disease. At the same time, the described patient had almost all the most characteristic clinical features of LP, manifested the disease with a full-blown nephrotic syndrome, although SLE debuted earlier with the articular syndrome and constitutional symptoms of mild severity, as well as damage to the thyroid gland by the type of autoimmune thyroiditis, and therefore the diagnosis was not established on time. Subsequently, at the first recurrence of the disease, the patient demonstrated a vivid SLE clinic with skin lesions in the form of «butterfly-type» erythema, hematological manifestations represented by cytopenic syndrome, constitutional symptoms, as well as immunological disorders in the form of detection of ANF, a high titer of antibodies to double-stranded DNA, antibodies to several other extractable nuclear antigens. The morphological feature of LP in our patient was a picture of MCD without signs of mesangial LN of class I or II. The presence of podocytopathy in combination with the clinical and immunological manifestations of SLE at the onset of the disease, the appearance of new characteristic signs of lupus in the future, and the obvious relationship between relapses of NS and exacerbations of the disease, made it possible not only to return the previously rejected diagnosis of SLE but also to classify kidney damage as lupus podocytopathy. In connection with relapses of NS, tacrolimus was prescribed.