Asymptomatic bacteriuria is a microbiological diagnosis which should be based on results of culturing of urine samples collected avoiding contamination and transported to the laboratory as quickly as possible to limit bacterial growth. Asymptomatic bacteriuria is common, however its prevalence widely varies in population with age, sex, sexual activity, the presence of genitourinary abnormalities and the associated diseases. In spite of the fact that in persons with аsymptomatic bacteriuria the risk of a symptomatic urinary tract infection is increased, its treatment does not reduce the frequency of symptomatic infection. Screening and treatment of asymptomatic bacteriuria is justified at pregnant women, before traumatic urological researches, surgical operations on genitourinary system, kidney transplantation in women with a remaining bacteriuria after excision of urinary catheter.

Cystinosis is caused by mutations in the CTNS gene that encodes a lysosomal cystine transporter, cystinosin. It is characterized by accumulation of cystine in the lysosomes throughout the body. In the majority of the patients, this leads to generalized proximal tubular dysfunction (also called DeToni–Debré–Fanconi syndrome) in the first year and progressive renal failure during the first decade. Extrarenal organs are also affected by cystinosis, where clinical symptoms are manifested mostly after 10 years of age. The cystine-depleting agent, cysteamine, significantly increases life expectancy of patients with cystinosis, but offers no cure due to the complexity of the disease mechanism. In this review, current knowledge on the pathogenesis of cystinosis is described.

The results of a comparative analysis of laparoscopy (128 patients) and mini-laparotomy (109 patients) in order to implant a peritoneal catheter are presented. The incidence of dislocation and dysfunction of the catheter, dialysate leakage, infectious and surgical complications are assessed. We describe several methods of laparoscopic implantation of the peritoneal catheter for the use in various clinical situations. The results confirm the advantage of laparoscopic technique of the implantation of peritoneal catheter which allows one to reduce the incidence of catheter dislocation to 2,34% and minimize the incidence of infectious and surgical complications of intervention, which ultimately improves the quality of life of patients treated with peritoneal dialysis and survival of this method of renal replacement therapy.

The purpose of this study was to determine the frequency and the risk factors of renal failure and to assess their range in patients with HIV infection. The frequency of renal failure among HIV-infected patients in Moscow city was studied. The screening studies of markers of renal failure were performed on 610 patients with HIV infection. Renal biopsy was performed in 15 patients with nephrotic syndrome. Taking into account the steady growth of of HIV infection, the results obtained in screening prospective epidemiological study showed an increase in the calculated value of the prevalence of renal lesions among HIV-infected patients. In 24,9% patients with HIV infection was revealed the transient character of proteinuria. Persistent proteinuria was recorded in 10,8% of cases. Renal impairment was found in 48% of patients with proteinuria. It is shown that the predisposing factors of nephropathy may be a high viral load (HIV RNA of more than 100 000 copies/ml) and depression of immune system (CD4⁺-lymphocytes less than 200 cells/ml). The morphological structure of chronic glomerulonephritis in HIV-infected patients with nephrotic syndrome is presented with the focal segmental glomerulosclerosis and renal immunocomplex. The data obtained allow us to conclude that HIV-infected patients are at high risk of renal failure and are in need for dynamic monitoring with the purpose of an early detection of renal pathology.

The aim of this study was to compare the efficacy of different calcineurin inhibitors after kidney transplantation. Data of 545 recipients transplanted between years 2007 and 2009 were analyzed. The patients were divided into 2 groups according to received therapy. Patients of the 1^st group (n = 354, males 59%) received cyclosporine, the 2^nd group recipients (n = 191, males 59,5%) were given tacrolimus. Three-year patients and graft survival, the incidence of acute rejection and renal function were compared. The frequency of infections, post-transplant diabetes, arterial hypertension, hyperlipidemia and proteinuria were also studied. Acute rejection episodes were characterized by a decline in kidney function accompanied by well-established diagnostic features on kidney allograft biopsy. Three-year patients survival was 95,3% in group 1 and 89,9% in group 2 (p < 0,12), grafts survival was 94,3 and 91,7% (p < 0,6). Acute rejection episodes within 3 months after transplantation were similar: 15,5% in the 1^st group and 16,2% in the 2^nd group (p < 0,46), after 3 months they were more often in 1^st group: 5,4% vs . 2,4% (p < 0,049). Renal function and proteinuria were similar in compare groups. Mean serum creatinine level was 0,139 ± 0,04 and 0,137 ± 0,01 mM and proteinuria was 0,31 ± 0,032 and 0,33 ± 0,06 g/day in groups 1 and 2, respectively. The rate of infections in the groups were similar: 29,1% vs. 31,8%, respectively (p < 0,32). However the risk of death from infectious was higher in patients who received tacrolimus: 5,8 vs . 1,0, respectively (p < 0,039). Post-transplant diabetes mellitus was more often found in group 2: 31 and 20%, respectively (p < 0,016). Arterial hypertension and hyperlipidemia were found more often in group 1. Our results gave evidence for similar efficacy of cyclosporine and tacrolimus. There are no differences in patient and graft survival, graft function, incidences of acute rejection, infections and proteinuria. There is evidence that arterial hypertension and hyperlipidemia are higher with cyclosporine vs. tacrolimus, there are also evidences that post-transplant diabetes mellitus is more common on tacrolimus than cyclosporine.

The paper summarizes the experience of renal replacement therapy (RRT): peritoneal dialysis, PD, and continuous veno-venosus hemodiafiltration, CVVHDF in 50 children under 3 years old with acute and chronic renal failure in a single center during years 2008–2009. RRT was started by PD in 13 children (26%), by CVVHDF in 37 children (74%); 22 children were treated by both methods. CVVHDF was applied more often as the «starting» method in very sick, unstable patients, while PD was used in stable patients with isolated renal failure. The complications of RRT were observed in 13 of 31 children (41,9%) on PD (dialysate leakage, peritonitis), and in 16 of 41 patients (39%) on CVVHDF (circuit thrombosis, hemorrhage). In total 10 of 50 (20%) patients on RRT have died during the acute period. The mortality rate in patients with ARF was lower in children with primary renal damage rather than in those with secondary renal failure (2 of 31, 6,5% vs . 5 of 9, 55,6%, p = 0,0012). The mortality rate in CRF was 30%. The deceased patients were younger; the rate of sepsis, multiorgan failure, and the necessity of cardiotonic support in these patients was significantly higher, and had lower arterial blood pressure than survivals. In general, both PD and CVVHDF are the effective methods of RRT in children under 3 years old. The combination of these methods allows one to treat the patients with dialysis therapy complications successfully.

The results of a cohort study of potential association with single nucleotide polymorphisms (SNP) in the NPHS1 gene that encodes nephrin, with the efficacy of immunosuppressive treatment and progression of sporadic SRNS in children are presented. Fifty-three children with primary non-familial SRNS aged 16,0 (12,0; 17,0) years were studied. Renal biopsy showed FSGS in 49,1%, mesangial proliferative GN in 22,6%, MPGN in 15,1%, membranous nephropathy in 7,5% and MCD in 5,7% of patients. Low frequency of heterozygous mutations in the NPHS1 gene (1,9%) in children with sporadic SRNS was found. Four types of SNP in the NPHS1 gene were identified in 58,5% children, majority of the SNP were heterozygous. Efficacy of immunosuppressive treatment was not different significantly in patients with SNP in comparison those without them. There was no significant differences in the frequency of GFR <60 mL/min/1,73 m², the rate of eGFR declined per year and cumulative renal survival in patients with SNP in the NPHS1 gene. An association of the SNP in NPHS1 gene and progression of sporadic SRNS in children was not found.

The gout prevalence has increased during last decade, 30–50% of gouty patients have kidney involvement. Objective. To assess kidney function and to identify possible relationship severity of the gout with kidney dysfunction we studied 29 healthy volunteers and 62 patients with gout and no signs of chronic kidney disease (CKD). Results. In gouty patients with normal glomerular filtration rate, without proteinuria we have found not only hyperuricemia 510 [410; 633] mM, but decreased uric acid (UA) clearance 5,3 [3,8; 7,5] versus 10,3 [7,4; 11,4] ml/min/1,73 м² and excretion fraction, against background increase of filtered volume and reabsorbion. There is a significant linkage between the UA level and the presence of tophi, quantity of affected joints, exacerbation frequency, X-ray stage, and severity indexes. A relationship was found between the functional failure of arthritis with renal exchange of UA (excretion fraction), but not with the level of blood UA. Conclusion. To set up the of purine metabolism, the prognosis of gout and selection of medication it is important to evaluate the UA level, the UA clearance and the excretion fraction. Decreased UA clearance may be suggested as the first stage of uric acid nephropathy as the UA clearance £7 has sensitivity of 69%, specificity of 77% and + likelihood ratio 3.

We present a rare case of acute T-lymphoblastic leukemia/lymphoma manifested by acute kidney injury and diagnosed after the kidney biopsy. The difficulties in differential diagnostics of obscure acute renal injury, as well as the variants of kidney involvement in lymphoproliferative disorders are discussed.