Correction of hyperphosphatemia remains the most important but unsolved problem in the treatment of patients with chronic kidney disease (CKD) stages 4 and 5 and patients on chronic hemodialysis. Currently, to reduce the level of serum phosphorus used to restrict an intake of dietary phosphorus, variety on the duration and frequency of hemodialysis, and the use of different phosphate binders. However this treatment in half of the cases does not allow reaching normal values of phosphorus in serum, and that leads to an increase in PTH and FGF23 and the development of multiple complications. Recently for correction of hyperphosphatemia local inhibitors of phosphorus transporters, which are localized in humans in the kidneys and gastrointestinal tract have began to be used. The Na+/H+-exchanger regulates the absorption of sodium in the gastrointestinal tract, controls volemia and intracellular pH, and provides paracellular absorption of phosphorus. The inhibitor Na+/H+-exchanger type 3 (NHE3) Tenapanor hydrochloride reduced sodium and phosphorus absorption in the intestine. Additional indications for the prescribing of Tenapanor hydrochloride are hypertension, heart failure, and bowel disease. The pan-phosphate transporter inhibitor EOS789 decreased the activity of Na/Pi-IIb, Pit-1, and Pit-2, which are involved in phosphorus absorption in the intestine and has proven itself well under experimental conditions. The selective inhibitor of the Na/Pi IIa transporter PF-06869206 had a hypophosphatemic effect in patients with CKD and preserved diuresis. The most important specialty of local phosphorus transporter inhibitors is safety and the absence of serious adverse reactions during use. Local inhibitors of phosphate transport in combination with phosphate binders can control hyperphosphatemia in patients with chronic kidney disease. This review is d

Formulas for estimation of the glomerular filtration rate (GFR) in pediatric practice differ from those used to assess kidney function in adults. The KDIGO 2012 Clinical Practice Guidelines for the Evaluation and Management of Chronic Kidney Disease recommends using the CKiD bedside (2009) equation for children and the CKD-EPI (2009) equation for adults to estimate GFR based on serum creatinine. These formulas were developed independently using different patient datasets. As such, there is a significant discrepancy in the estimated GFR in patients aged 17-18 years of age obtained using the different equations. In recent years, scientists from the United States and Europe have conducted several studies on the development and validation of new GFR-estimating formulas. An analysis of these published data is needed to identify the optimal GFR estimation approach for patients transitioning from pediatric to adult health care services. For this, a narrative review was carried out. The problems in estimating GFR in adolescents and young adults and the proposed ways of solving them are presented in a historical context. It was found that there is currently no unified approach for estimating GFR in this age group since none of the existing formulas is sufficiently accurate. New formulas developed in recent years, such as EKFC and CKiD U25, require further research for external validation. Before the adoption of consensus decisions, ensuring the continuity of GFR estimation in adolescents and young adults is possible by using several formulas simultaneously with the specification of the formula’s names and the creatinine determination method listed on the medical documentation.

In the context of the COVID-19 pandemic, patients with end-stage CKD receiving hemodialysis replacement therapy (HD) were at risk of SARS-CoV-2 infection due to the specifics of treatment and the immunodeficiency state caused by uremia. The aim of the study was to analyze the characteristics of the course, prognostically unfavorable factors, and outcome of COVID-19 in HD patients of the second wave of the pandemic. Materials and methods: a retrospective study was carried out on the material of observations of 325 HD patients infected with SARS-CoV-2 in the period from 09/01/2020 to 12/31/2020. The patients' age was 60.1±14.0 years. The duration of HD treatment was 30.0 (9.5; 66.0) months. The endpoint was taken as the discharge from the hospital or death. Results: in 264 out of 325 (81.2%) patients, the diagnosis of COVID-19 was confirmed by the identification of SARS-CoV-2 RNA. CT scan of the chest showed signs of viral pneumonia in all patients. Mortality was 15.1% (49 out of 325 pts). In 79.7% of patients, the cause of death was ARDS. Comparative analysis showed that patients with a fatal outcome (group 2) were older (69.2±10.6 years) than patients with a successful course (group 1) of the disease (58.5±13.9 years), and differed in higher comorbidity index (7.8±1.9 versus 5.9±2.2, respectively). SpO2 in groups 2 and 1 was 65.2±10.1% and 92.1±6.4%, respectively (p<0.001). In the deceased patients, anemia, leukocytosis, thrombocytopenia, and hypoalbuminemia were significantly more pronounced, as well as indicators of GGT, alkaline phosphatase, ferritin, CRP, LDH, and D-dimer. In the fatal group, the proportion of patients with a procalcitonin level of more than 2 ng/ml was also higher. In multivariate analysis, only high comorbidity index and the need for mechanical ventilation were the independent predictors of the unfavorable outcome. In the group of patients with the favorable outcome, the combined therapy with immunobiological drugs and dexamethasone were used significantly more often than in the deceased group, while the frequency of their “isolated” use in the compared groups was comparable. Conclusions: COVID-19 in HD patients is characterized by severe course and high mortality. Independent predictors of an unfavorable outcome of the disease were a high comorbidity index and the need for invasive lung ventilation. Early use of immunobiological drugs and dexamethasone in combination with anticoagulants increases the effectiveness of treatment of severe forms of SARS-CoV-2 infection in HD patients.

Currently, overweight and obesity, in various subjects including children, are the most serious problems in many countries of the world. Kidney injury in patients with obesity is developed imperceptibly, without clinical symptoms. Known markers of kidney disease, associated with obesity are increased serum creatinine, albuminuria, proteinuria, arterial hypertension appearing in the late stages of the disease. The aim of our study was the comparative analysis of urinary markers of renal injury (KIM-1, NGAL, IL-18, β2-m) in obese children and healthy ones (control group). Materials and methods. The study included 84 children aged from 4 to 17 years: 34 obese patients and 50 children of the control group. All children were examined for urinary markers of kidney injury: KIM-1, NGAL, IL-18, and β2-m; the data of the two groups of patients were compared. Results. Statistically significant differences were found of three from the four studied indicators in obese children and in children of the control group: NGAL, KIM-1 and IL-18; in the group of obese children these urinary markers had higher values than in the control group. The concentration of β2-m in urine was similar in both groups of children. When analyzing the normalized data, the results turned out to be the same: statistically significant differences were found for NGAL/Cru (ng/mg), KIM-1/Cru (pg/mg), and IL-18/Cru (pg/mg). Conclusion. It seems to us rational to use such urinary markers as NGAL, KIM-1, IL-18 for detecting early kidney injury in children with exogenous constitutional obesity.

Aim: to evaluate the medical and social characteristics and quality of life (QoL) of the patients with CKD on program hemodialysis and to identify factors associated with QoL of this category of patients. Methods: 166 patients with CKD on hemodialysis have been involved in the study, living in Moscow (116) and Samara (50). The patients' QoL was evaluated simultaneously using the SF-36 questionnaire. The study was conducted from February to June 2021. Statistical data processing was carried out using SPSS.22. Results: median age of the patients was 60.0 years (from 21 to 90). There were 43.9% of men, 56.1% of women; 51.8% were married. A significant proportion of patients were persons with higher and secondary specialized education (86.0%). Most of the patients did not work and were in the group of disabled people (51.8%) or pensioners (28.7%). 18.3% of patients continued to work with a disability. The median duration of hemodialysis was 48.0 months (IQR=22.0-108.0). Almost all patients noted the presence of restrictions associated with CKD and the need to undergo hemodialysis sessions. QoL indicators among patients on hemodialysis were worse than among healthy people. The physical component of health is particularly affected. A negative correlation was revealed between the total physical and total psychological components of health and factors such as age, disability group, and sedentary lifestyle; a positive relationship was revealed with education, employment, financial situation, housing, living conditions, and motor activity. QoL of the patients improved at 2-5 years of hemodialysis and decreased in subsequent years. The differences in the medical and social characteristics and QoL of the patients in Moscow and Samara were revealed. Conclusion: QoL of the patients with CKD on hemodialysis is worse than that of healthy people, especially the physical component of health suffers. The subjective assessment by patients on hemodialysis of their health-related quality of life can serve as an important indicator for evaluating the results of renal replacement therapy. When planning and implementing measures aimed at improving QoL at the population and individual levels, it is important to take into account information about the medical and social characteristics of patients.

Renal biopsy (RB) is the gold standard for diagnosing causes of kidney transplant (KT) dysfunction. One of the rarest biopsy-related complications is the simultaneous formation of pseudoaneurysm (PA) and arteriovenous fistula (AVF) of KT. The first line diagnostics in such cases is comprehensive allograft ultrasonography (US). The final diagnosis is being established by the results of contrast-enhanced multispiral computed tomography (CE-MCT). A 54-year-old man with end-stage kidney disease secondary to chronic glomerulonephritis was admitted for the start of maintenance hemodialysis. He had received repeated cadaveric KT in 1996 and 2011. The routine RB was performed in 2018, the chronic transplant glomerulopathy was verified. Comprehensive allograft US was performed in the course of hospitalization. B-mode: anechoic ovoid lesion similar to simple cyst and two vessels connected to it are visualized at the border of the midpole region with the lower pole of the allograft (fig. 1a). The size of the lesion is 15×18×14 mm, there are signs of weak pulsation. Color Doppler demonstrated significant depletion of vascular pattern. A mosaic pattern with a speckling of perivascular soft tissue caused by tissue vibration was observed in the lesion projection (fig. 1b). Pulsative Doppler: low-resistance high-velocity spectrogram with turbulent flow in feeding artery (fig. 1c) and arterialized blood flow presumably in draining vein. The data obtained corresponded to the combination PA and AVF. CE-MCT with post-processing image processing was performed: MIP (Maximum Intensity Projection) - (fig. 2a) and VR (Volume Rendering) are presented in fig. 2b (front view) and fig. 2c (left and rear view). The subsegmental branches (large caliber 4-4,5 mm) of the KT lower pole are spirally crossed and form on the top of the intersection of the aneurism with irregular ovoid shape and size 16×19×15 mm. The draining branch forms the shunt (arrows) with renal vein (RV) (fig. 2c). RV and external iliac vein (let V, fig. 2c) are contrasting in the arterial phase, external iliac artery - let A. So, the diagnosis of simultaneous formation of PA and AVF was confirmed by CE-MCKT data. Taking into account the complete loss of the function, the transplantectomy was recommended. The authors declare no conflict of interest. Informed consent for publication of patient's information and images was obtained from our patient.

Aim: To determine the pregnancy complications and outcomes in patients with primary chronic glomerulonephritis (CGN) in the era of placenta-associated complications prevention. Methods: 120 pregnancies in 114 women with CGN and chronic kidney disease (CKD) grades 1-4 were included; 20 pregnancies in 20 healthy women were considered as the control group. All women with CGN received antiplatelet agents to prevent preeclampsia (PE); in the presence of additional risk factors, heparin was prescribed. Results: A favorable pregnancy outcome in CGN was observed in 94.2% cases. In patient with CGN, compared healthy women, PE was more often: in 25.2% versus 0.0%, p=0.013; placental insufficiency in 28.3% versus 0.0%, p=0.004; urinary tract infection in 19.2% versus 0.0%, p=0.044; cesarean section (CS) in 33.9% versus 10.0%, p=0.036. The body weight of newborns in CGN group was significantly lower comparing control: 3100 [Q1-Q3: 2800; 3485] g versus 3355 [Q1-Q3: 3200; 3710] g, p=0.015. The incidence of PE, fetal growth retardation, preterm delivery, CS, treatment of newborns in ICU was highest in patients with CKD G3 and G4: 35% (G3) and 66.7% (G4), 50% and 100%, 45% and 100%, 70% and 100%, 31.6% and 100%, respectively. The complication frequency depended on baseline proteinuria more than 1g/day (PU) and arterial hypertension (AH). Frequency of PE in women without PU/without AH was 7%, with AH without PU - 37.5%, with PU without AH - 44%, with PU and AH - 50%, p=0.0002; preterm delivery - 3.5%, 15.8%, 22.2%, 45.5%, respectively, p=0.0013; treatment of babies in ICU - 1.8%, 5.3%, 11.1%, 45.5%, respectively, p<0.0001. Independent risk factors for preterm delivery were CRF in mother - RR 16.182 [95%CI 4.669-56.081], p<0.0001; placental insufficiency - RR 4.750 [95%CI 1.534-14.709], p=0.011; the absence of severe PE was a protective factor: OR 0.115 [95%CI 0.069-0.192], p=0.016. Nine out of 114 (7.9%) patients with CGN reached CKD G5 32.3 [Q1-Q3: 21.1; 50.0] months postpartum. Conclusion: We observed a high incidence of favorable pregnancy outcomes in women with CGN. Most the unfavorable outcomes were due to PE and placental insufficiency. Preconception care and prevention of placenta-associated complications can improve gestational outcomes in patients with CGN.

Schimke immuno-osseous dysplasia (SIOD) is a rare autosomal recessive disorder characterized by the combination of spondyloepiphyseal dysplasia with growth retardation, progressive proteinuric glomerulopathy, specific phenotype, and T-cell immunodeficiency. Clinical cases of an 11-year-old boy and a 15-year-old girl are presented. The boy was born full-termed with intrauterine growth retardation from healthy unrelated parents. The girl was born prematurely from healthy parents with burdened family history (a younger brother with chronic kidney disease 5 (CKD G5) died at the age of 6). The patients have the phenotypic features of SIOD. In both cases, from the first year of life, there was growth retardation and skeletal disorders. At the age of 4 years in the boy and 14 years in the girl nephrotic syndrome refractory to pathogenic treatment occurred, which led to the CKD G5. Later after kidney transplantation, the boy had recurrent infections, seizures, stroke. The minimization of infectious complications was achieved with a 2-component therapy regimen (methylprednisolone and tacrolimus), excluding mycophenolate mofetil. Both children have T-cell deficiency and hypothyroidism. Only after kidney transplantation in the boy and the onset of CKD G5 in the girl was SIOD suspected. A compound heterozygous mutation in the SMARCAL1 gene was revealed by NGS: an identical pathogenic mutation c.G2542T (p.E848X) was found in exon 17 in both cases; in the boy c.C2290T (p.R764W), in the girl c.C2290G (p.R764G) were revealed in exon 15. The presence of nephrotic syndrome, especially morphologically focal segmental glomerulosclerosis, with pronounced growth retardation in a child at the onset of the disease should always alert doctors in terms of the diagnosis of Schimke syndrome.

Chronic Kidney Disease

Kidney transplantation

Pediatric nephrology

Acute kidney injury