Idiopathic nephrotic syndrome newly affects 1-3 per 100,000 children per year. Approximately 85% of cases show complete remission of proteinuria following glucocorticoid treatment. Patients who do not achieve complete remission within 4-6 weeks of glucocorticoid treatment have steroid-resistant nephrotic syndrome (SRNS). In 10-30% of steroid resistant patients, mutations in podocyte-associated genes can be detected, whereas an undefined circulating factor of immune origin is assumed in the remaining ones. Diagnosis and management of SRNS is a great challenge due to its heterogeneous etiology, frequent lack of remission by further immunosuppressive treatment, and severe complications including the development of end-stage kidney disease and recurrence after renal transplantation. A team of experts including pediatric nephrologists and renal geneticists from the International Pediatric Nephrology Association (IPNA), a renal pathologist, and an adult nephrologist have now developed comprehensive clinical practice recommendations on the diagnosis and management of SRNS in children. The team performed a systematic literature review on 9 clinically relevant PICO (Patient or Population covered, Intervention, Comparator, Outcome) questions, formulated recommendations and formally graded them at a consensus meeting, with input from patient representatives and a dietician acting as external advisors and a voting panel of pediatric nephrologists. Research recommendations are also given.

Nephrotic syndrome is a serious kidney disease that leads to life-threatening complications and requires repetitive hospitalization and long-term therapy. Therapy for nephrotic syndrome in its onset is aimed at inducing remission and includes taking prednisone. While most children are steroid responsive, approximately half of patients have subsequent relapses and become frequently relapsing or steroid-dependent, which requires using of corticosteroid-sparing agents. Despite a huge number of studies accessing the effectiveness of immunosuppressive therapy, there is still no consensus for first-line therapy. The potential risk of carcinogenicity and infertility led to reduced use of alkylating agents. Due to insufficient effectiveness and low availability, the non-specific immunostimulator levamisole is rarely used. Calcineurin inhibitors have been demonstrated good effectiveness in maintaining stable remission. However, the formations of cyclosporine dependence, nephrotoxicity, arterial hypertension, and cosmetic side effects have become an essential problem. In recent years, mycophenolate mofetil has been increasingly used. The results of multicenter studies demonstrate maintenance of remission in most of the patients, in the absence of significant serious complications. As a rule, mycophenolate mofetil is prescribed if there is a proven insufficient effect or toxicity of cyclosporine, while its role as a first-line immunosuppressive drug has not been sufficiently studied. The lack of steroid-sparing action of these drugs and the critical degree of chronic steroid intoxication dictates the need to use a course of biological therapy with rituximab after careful exclusion of contraindications. The introduction of glucocorticoid therapy played a huge role in increasing the survival rate of children with nephrotic syndrome. After achieving remission in most patients ceased to be a problem, a new challenge was the formation of steroid dependence, the need for repeated courses and/or long-term maintenance therapy with prednisone. To overcome this dependence, various immunosuppressive drugs have been used and studied for half a century, which is the subject of this review.

The letter provides a detailed answer to the question about the boundary between low and high flux dialyzers in the practice of organizing dialysis in the CHI system. Rapid progress in the development of new dialysis membranes and technologies is not always quickly reflected in regulatory documents and clinical guidelines. It is generally accepted to consider the sieving coefficient for β2-microglobulin more than 0.6 or clearance for β2-microglobulin more than 20 ml/min as the lower limit of the parameters of high-flux dialyzers. However, for modern high-flux dialyzers, the ultrafiltration coefficient has lost its value, and the sieving coefficient for β2-microglobulin, having approached one, has ceased to distinguish between the types of dialyzers. Narrowing the width of the membrane pore size distribution made it possible to bring the permeability boundary close to albumin, simultaneously limiting its loss.

Aim. To assess the prevalence of acute renal injury (AKI) among patients who underwent surgery for primary hyperparathyroidism (PHPT), to analyze the possible risk factors for the development of postoperative AKI. Materials and methods. A retrospective cohort study included 290 patients who underwent successful selective parathyroidectomy (PTx) for PHPT. We did not include patients who underwent re-operative surgeries. AKI was defined according to KDIGO-2012 criteria. Results. 106 of 290 patients (36.6%) met AKI criteria after PTx. High preoperative PTH values were associated with AKI risk (median 17,75 pmol/L [Q1-Q3: 12; 24.2] in AKI group vs 13.8 pmol/L [Q1-Q3: 10,2; 19.6] in non-AKI group, p=0.0004). High ΔPTH before/after surgery was also associated with AKI risk (median 16.7 pmol/L [Q1-Q3: 10; 23] in AKI group vs 11.35 pmol/L [Q1-Q3: 7.4; 17] in non-AKI group, p<0.0001). In patients who developed AKI maximum size of the parathyroid adenoma was significantly greater: 20 mm [Q1-Q3: 10; 25] vs 15 mm [Q1-Q3: 10; 20] in non-AKI patients, p=0.0184. AKI risk was also associated with high preoperative serum calcium level: 2.83±0.29 mmol/L in AKI group vs 2.71±0.22 mmol/L in non-AKI group, p=0.0158. AKI risk was significantly higher in those with proteinuria: RR=1.9 [95%CI 1.19; 3.54], OR=3.67 [95%CI 1,5; 8.73], р=0.0061. Notable, neither preexisting chronic kidney disease (RR=1,37 [95%CI 0.93; 1.9], OR=1,7 [95%CI 0.9; 3.2], p=0.1073) nor baseline estimate glomerular filtration rate (84.45 ml/min/1.73 m2 [Q1-Q3: 65.5; 96.6] and 76.6 ml/min/1.73 m2 [Q1-Q3: 64.9; 90.6] for AKI and non-AKI patients respectively, р=0.118) were not associated with the risk of postoperative kidney function impairment. Patients of age 60 years and older had greater risk of AKI: RR=1.32 [95%CI 1.03; 1.72], OR=1.72 [95%CI 1.07; 2.83], p=0.0265. There was no association of AKI with perioperative use of contrast media in small doses (р=0.245), or intraoperative hypotension (p=0,79). Conclusions. We observed a high prevalence of AKI in patients after parathyroidectomy for primary HPT. Preoperative risk stratification may help early recognition and treatment of renal function impairment. For those at risk of AKI, careful monitoring of renal function is necessary during the postoperative period.

The aim of this study was to evaluate the efficacy of a hybrid surgical approach in treatment of vascular access graft thrombosis, which consist of open thrombectomy to remove clots and endovascular balloon angioplasty to treat stenotic lesions. Material and methods: 9 patients were included, primary and primary-assisted patency at 1, 3, and 6 months were evaluated. Six were females and three were males. The patient median age was 50±12 years. The median time on hemodialysis (HD) treatment was 77 months. There were 6 upper arm grafts and 3 lower leg grafts. Ten hybrid thrombectomies were performed on 9 patients. All procedures were done under local anesthesia. No central venous catheters for acute HD were implanted. Ultrasound Dopplerography (USDG) was performed at 6 months follow up period. Results: primary vascular access graft patency rates at 12, 24 and 36 months were 66%, 44% and 11%, respectively, with 100% success. Primary-assisted vascular access graft patency rates at 1, 3, and 6 months were 100%, 88% and 77%, respectively. 1/9 (11%) stent-graft was implanted at the venous graft anastomosis due to inappropriate result of balloon angioplasty (recoil >50%). No sights of clinically significant pulmonary embolism, local wound infection, and puncture zone were detected. Conclusion: hybrid surgical approach could provide good early and late outcomes as a treatment modality of vascular access graft thrombosis. Usage of ultra-high pressure balloons provides good clinical and angiography results. Use of stent-graft could provide a good clinical result concerning the patency rate after failed balloon angioplasty.

The systemic lupus erythematosus (SLE) negatively affects women's reproductive health. Treatment of SLE can cause premature ovarian failure, and lupus pregnancy is associated with an increased incidence of obstetric complications. Active lupus nephritis has an independent negative effect on gestational outcomes. Differential diagnosis of lupus nephritis relapses during pregnancy and preeclampsia can be difficult due to the similarity of symptoms. We present a clinical case of two pregnancies with different outcomes in a patient with lupus nephritis. During the first pregnancy, late diagnosis of SLE, gestational exacerbation of lupus nephritis, absence of immunosuppressive therapy caused nephrotic syndrome and arterial hypertension in the mother, early delivery at 32 weeks of gestation, the birth of a child with neurological complications and respiratory disorders that led to his sudden death at 7 months. Treatment with corticosteroids and pulses of cyclophosphamide caused remission of lupus nephritis but was complicated by amenorrhea. Therapy with estrogen-containing drugs has led to the restoration of fertility and did not cause a relapse of SLE. The second pregnancy occurred after preconception planning. During gestation, the patient received immunosuppressive therapy, low molecular weight heparin, and a small dose of acetylsalicylic acid. Complete remission of lupus nephritis was maintained throughout the pregnancy. Throughout pregnancy, complete remission of lupus nephritis persisted. Planned cesarean section was performed at 38 weeks of gestation, a healthy boy with a weight of 3330 g, height 51 cm was born, Apgar scores 8/9. Two months after childbirth mother demonstrated a mild relapse of lupus nephritis, which required an increased immunosuppressive therapy. The article is illustrated with photomicrographs and a comparative description of the morphological study of placental tissue. The features of the first placenta were dyssynchrony of villous tree (areas of premature maturation of the villi) and pronounced vascular changes - obliterative angiopathy of stem villi, small number of capillaries in terminal villi. These changes were probably related to SLE activity. The second placenta had well-vascularized terminal villi with wide capillaries, areas of compensatory angiomatosis. Thus, an important condition for a favorable pregnancy outcome with lupus nephritis is persistent remission of the underlying disease.

Peritoneal dialysis (PD) is a widely used method of renal replacement therapy (RRT) in children with stage 5 chronic kidney disease (CKD). The most common complication of PD and the leading cause of hospitalization for these patients is dialysis peritonitis. The vast majority of cases of dialysis peritonitis are caused by microbial infection of the abdominal cavity and demands antibiotic therapy. Dialysis peritonitis resistant to antibacterial therapy leads to the removal of the peritoneal catheter, to the temporary or permanent transfer of the patient to hemodialysis. However, some cases of dialysis peritonitis not responding to antibiotic therapy are represented by a separate form - eosinophilic peritonitis (EP), in which more than 10% of the dialysate cells are eosinophils, and which requires special approaches to therapy. The article presents three cases of EP in children demonstrating characteristic features of this complication: in two of the three patients, EP appeared after repeated abdominal surgery, eosinophils predominated in the dialysate cell count (68-95%), and blood eosinophilia was observed. In no case, bacteria growth in repeated dialysate cultures was detected. In all patients, EP resolved with corticosteroid therapy. In one case, after stopping EP, bacterial dialysis peritonitis developed. In addition to dialysate culture, differential diagnosis between EP and bacterial peritonitis was carried out by leukocytes count in a stained dialysate smear. The review of publications provides information on the incidence of EP according to foreign researchers, on the pathogenesis, symptoms, diagnostic methods, and therapy of this condition. Idiopathic and secondary EP are considered. Idiopathic EP is facilitated by factors directly related to peritoneal dialysis: peritoneal catheter material, dialysis solution components (including icodextrin), air entering the abdominal cavity when the peritoneal catheter is inserted and exchanges are performed, and mechanical stress of the peritoneum caused by the dialysis solution. Secondary EP may develop with the use of various drugs intraperitoneally or orally, with local or systemic infection (fungal, mycobacterial, parasitic) Timely diagnosis of EP in PD patients prevents long-term “empirical” antibacterial therapy, associated with the risk of fungal peritonitis, unjustified removal of the peritoneal catheter, and maintains PD as the optimal dialysis method in children.

Systemic vasculitis (SV) is a heterogeneous group of diseases. Their main morphological feature is inflammation of the vascular wall. The clinical manifestations depend on the type, diameter, and localization of the affected vessels and the activity of systemic inflammation. Vasculitis of small vessels is sometimes associated with antineutrophil cytoplasmic antibodies (ANCA-SV). The etiology of ANCA-SV is unknown although their development is associated with genetic factors, environmental exposure, medications, and infections. The key role was assigned to antineutrophil cytoplasmic autoantibodies to proteinase 3 and myeloperoxidase contained in primary neutrophil granules and monocyte lysosomes. Recently, the effector function of neutrophils was described: the release of neutrophil extracellular traps (NETs). NETs may contribute to the initiation of the autoimmune process. The role of an alternative complement pathway, in particular, anaphylatoxin C5A, and the C5A receptor (CD88) in the pathogenesis of ANCA-SV was demonstrated. B cells play a major role in the pathogenesis of ANCA-SV since they produce ANCA. ANCA-SV treatment is primarily aimed at suppressing the autoimmune and inflammatory process and removing ANCA using extracorporeal hemocorrection methods. Despite significant advances in the treatment of ANCA-SV the effectiveness of extracorporeal hemocorrection remains controversial. Some local small studies show positive results of plasma exchange. Nevertheless, large-scale studies have not revealed the long-term benefits of plasma exchange therapy. The effective use of plasma exchange in the treatment of anti-glomerular basement membrane (GBM) disease has been proven. The results of previous studies have shown that 40% of patients with the anti-GBM disease have ANCA circulating in the blood, in the predominant number of cases to myeloperoxidase. Only a few clinical cases describing the treatment of patients with double seropositivity have been reported. Here we present a clinical case of successful application of extracorporeal hemocorrection in the treatment of a patient with double seropositivity for ANCA and GBM antibodies.

Non-tuberculous pulmonary mycobacteriosis causes difficulties in both diagnosis and treatment due to the absence of reference laboratories in most thoracic clinics, the natural resistance of non-tuberculous mycobacteria to antibacterial drugs, and a large number of adverse events (AE) relative with medications prescribed for treatment this pathology. The pulmonary invasive aspergillosis was previously described as an infection associated with the risk of fatal complications and requires the administration of the antifungal therapy and a decrease in the immunosuppression intensity. End stage chronic kidney disease patients are one of the most vulnerable groups for concomitant respiratory infections, and the tolerability of antibacterial and antifungal drugs among this population need the further studies. That clinical case reflects the period of intensive phase of full- antimycobacterial therapy of pulmonary mycobacteriosis with co-infection - aspergillosis against the background of the biological anti-B cell therapy beginning of ANCA-associated vasculitis in a patient receiving replacement hemodialysis therapy. Administration of antibacterial drugs such as ethambutol 1.2 / b.i.d., rifampicin 0.45 / b.i.d moxifloxacin 0.4 / b.i.d, protionamide 0.5 / b.i.d. to a 55-year-old patient undergoing hemodialysis programmed with hepatoprotective agents, neurometabolic “protection”, taking iron-, calcium-, erythropoietin - containing drugs was associated with the occurrence of AE such as allergic skin rashes and dyspeptic symptoms (nausea, vomiting, diarrhea), which required dose adjustment, and subsequently, the discontinuation of protionamide. The identification of Aspergillus fungi growth by culture in fluid of bronchoalveolar lavage (BAL), required local endobronchial injection of voriconazole into the bronchus leading to cavity, taking into account the patient`s immunocompromised status, to prevent the occurrence of invasive pulmonary aspergillosis. This combined treatment caused a stabilization of chest CT changes (compaction and calcification of 2 cavities). At the same time, there was observed an increase of level BUN in serum and thrombocytopenia, which regarded as ANCA-associated glomerulonephritis progression and required the appointment of a genetically engineered anti-B-cell biotherapy with rituximab in rheumatological hospital. Combined therapy led to further positive clinical and radiological dynamics, normalization of indicators of clinical, biochemical blood tests, and a general improvement in the patient's well-being. Thus, this case demonstrates that the treatment of concomitant respiratory infections in such patients is associated with great difficulties with interpretation X-ray-laboratory tests, prescribing of drugs, AEs, and requires a multidisciplinary approach from different specialists.