OBJECTIVE:An evaluation of podocyte's molecular phenotype alterations in primary focal segmental glomerulosclerosis (pFSGS) and IgA nephropathy (IgAN). MATERIAL AND METHODS:The exploratory study included 14 cases of morphologically confirmed pFSGS, 14 cases of IgAN, and 12 negative controls. The negative controls comprised samples of the unaltered renal cortex obtained during laparoscopic nephrectomy in patients with malignant neoplasms of the kidney and bladder and without proteinuria. A quantitative immunomorphological study of Wilms tumour protein (WT1) expression and mesenchymal markers of podocytes (desmin and vimentin) was conducted on all kidney samples. The co-expression of the aforementioned molecules was analysed using confocal microscopy. RESULTS:Cases of pFSGS exhibited nephrotic syndrome with proteinuria of 9.3 (3.1-14) g/24 and typical glomerular alterations in light microscopy and ultrastructural analysis. In the IgAN group, proteinuria was less severe (1.2 (0.7-1.6) g/24). The estimated glomerular filtration rate in pFSGS and IgAN was similar (pFSGS: 85 (53-103) ml/min/1.72 m², IgAN: 76 (52-87) ml/min/1.72 m²; p=0.40). In both pFSGS and IgAN, there was a reduction in WT1 expression in podocytes and an increase in vimentin expression when compared to negative controls. Compared to IgAN and controls, pFSGS exhibited a lower prevalence of glomerular WT1 expression and higher expression of desmin, which was predominantly localised in WT1-negative glomerular areas in confocal microscopy. In pFSGS, decreased nuclear expression of WT1 and increased expression of desmin were observed in the parietal epithelium of the glomerular capsule. CONCLUSION:Bidirectional alterations in the glomerular expression of WT1 and intermediate filament proteins are apparent in pFSGS and IgAN. These findings are suggestive for the genomic reprogramming of podocytes and the parietal epithelium of the glomerulus as part of the epithelial-mesenchymal transition, determining the structural and functional disorders of these cells, more prominent in pFSGS.

The association between 25-hydroxyvitamin D (25-OH-D) levels and tubulointerstitial lesions was performed in patients with primary glomerulopathies. The study included patients with morphologically confirmed primary glomerulopathies (n = 90, age 38 (30-50), M:F 37:53) and an estimated glomerular filtration rate (eGFR) 64 (33-90) ml/ min/ 1.73 m2. The control group included 20 apparently healthy individuals of comparable age with eGFR> 90 ml / min / 1.73 m2. The patients mainly had a lack or deficiency of vitamin D levels. The serum concentration of 25-OH-D correlated with serum total protein (r = 0.41, p = 0.010), proteinuria (r = -0.26, p = 0.012) and tubular lesions (r = -0.42, p <0.05). In multiple regression analysis, the severity of tubular dystrophy was associated with the serum concentration of 25-OH-D (β = -0.33 ± 0.11, p = 0.046), despite the inclusion in the regression models of proteinuria level (β = 0.22 ± 0.11, p = 0.062). Decreased serum 25-OH-D levels are associated with proteinuria and tubular damage in patients with primary glomerulopathies.

OBJECTIVE:To study correlations between the clinical signs of dysfunction and pathological structural changes in the renal parenchyma in a group of Russian patients with AL amyloidosis in 2008-2015. SUBJECTS AND METHODS:A total group (At) including Group 1 with AL (kappa + lambda light chains) (n=46) was divided into subgroups: 2λ) 40 patients with AL-lambda (AL-λ); 3κ) 6 patients with AL-kappa (AL-κ). All the patients underwent standard laboratory and instrumental studies: determinations of the peak systolic and diastolic blood pressures (SBP and DBP, respectively, mm Hg), glomerular filtration rate (GFR) (ml/min/1.73 m2) by the EPI equation, daily protein loss (g/day). Polyclonal antibodies against kappa and lambda light chains, AA component, and transthyretin (DAKO, Denmark) were used as immunomorphological markers. Light optical structural changes were semiquantitatively assessed, by ranking the following analyzed sign: interstitial focal sclerosis (FS), tubular atrophy (TA), interstitial inflammatory infiltration (II) semi-quantitatively (0 - no; 1 - < 25%; 2 - <50%, 3 - >50% of the volume of a histological compartment). Glomerulosclerosis (GS) was defined as the percentage of sclerotic glomeruli. The extent of amyloid depositions in the renal parenchyma structures was estimated according to the procedure proposed by Ying Yao et al., 2013. RESULTS:The AL group showed a female preponderance (65.21%). The patients' mean age was 62±11 years. There were no significant differences in daily proteinuria and the levels of serum creatinine, GFR, SBP, and DBP between the groups. The predominant clinical manifestation in the patients was nephrotic syndrome. A comparative analysis of the pathomorphological criteria for the spread of amyloid masses and the markers of fibroplastic processes revealed no statistically significant differences in the studied groups. Correlation analysis of the spread of AL deposits in the renal parenchyma in the patients of Group 1 and Subgroup 2λ, as well as laboratory data showed that there were significant (p<0.05) correlations with GFR, serum creatinine, unlike in Subgroup 3κ. At the same time, the analysis demonstrated that daily proteinuria had a significant positive correlation with VA, IA, GA, and TA values in Subgroup 3κ, unlike in Group 1 and Subgroup 2λ. Positive correlations were found between glomerulosclerosis and VA in Subgroup 2 λ and IA in Group 1. Sclerotic (FS and TA) changes in the tubular interstitium (TIN) were significantly positively correlated with all the indicators of AL (GA, VA, IA, TA) in the examinees in Group 1 and Subgroup 2λ, but not in Subgroup 3κ. Inflammatory TIN infiltration showed statistically significant (p<0.05) positive correlations with IA and VA in Group 1 and Subgroup 2λ and their absence in subgroup 3κ. CONCLUSION:: The retrospective analysis of nephrobiopsy specimens from of patients with AL amyloidosis revealed that kidney damage was mainly associated with the development of λ-associated AL amyloidosis. The clinical and laboratory parameters were correlated with the pathomorphological criteria for loading the renal parenchyma with amyloid masses. The findings suggest that there are clinical and morphological features of the subclasses of AL amyloidosis, which may be of value for predicting the course and progression of the disease.

Ultrastructural changes in podocytes are an important diagnostic and prognostic marker for nephropathies. However, the biomedical understanding of detected submicroscopic changes in podocytes remains controversial.OBJECTIVE:To investigate the relationship between the ultrastructural changes of podocytes (fusion of cytopodia and denudation of the basement membrane as a result of their desquamation) with a number of clinical and laboratory indicators of kidney dysfunction in case of non-proliferative glomerulopathies (NPGP). Thirty-seven patients (23 men, 14 women) with NPGP, including 8 with focal segmental glomerulosclerosis (FSGS), 17 with membranous nephropathy (MN), and 12 with minimal change disease (MCD), were examined.SUBJECT AND METHODS:All the patients underwent standard laboratory and instrumental studies: determinations of the levels of total serum cholesterol (mmol/l), total serum protein (g/l); serum albumin (g/l); CKD-EPI glomerular filtration rate (GFR) (ml/min/1.73 m2), and daily protein loss (g/day). Light optical changes were measured; completely sclerotic and/or focally segmentally sclerotic glomeruli were taken into account. Quantitative ultrastructural stereological analysis was carried out estimating the cytopodium width (CPW) and the degree of glomerular basement membrane denudation (GBMD) (%).RESULTS:NPGP cases showed the largest number of sclerotic glomeruli in FSGS, which was accompanied by the lowest level of daily proteinuria and GFR. Quantitative values of CPW were associated with the level of daily protein loss (r=0.47; p < 0.05) and serum albumin (r=-0.57; p <0.05) in patients with nephrotic syndrome. In MN, the absolute value of CPW was larger than that in the other two patient groups. A correlation analysis of CPW and GBMD values among patients with NPGP revealed a statistically insignificant negative relation between these morphometric parameters. However, when a subgroup of patients with podocytopathies (only MCD and FSGS) was identified in the study group, this relationship was found to be significant (r=-0.54; p=0.012).CONCLUSION:The patients with NPGP exhibited a relationship between the severity of nephrotic syndrome and proteinuria/hypoalbuminemia, on the one hand, and CPW, on the other. The established negative relationship between CPW and the percentage of GBMD in the subgroup of patients with podocytopathies may be due to the early stages of podocyte injury, which are accompanied by transient GBMD.

AIM:To analyze the clinical and morphological manifestations of membranous nephropathy (MN) and to evaluate the efficiency of its therapy.MATERIAL AND METHODS:MN cases in 2009 to 2016 were retrospectively detected with a subsequent analysis of patients with primary MN (PMN). The titer of IgG-autoantibodies to phospholipase A2 receptor (anti-PLA2R Ab) was determined by an indirect immunofluorescence assay. Treatment outcomes, such as the time course of changes in proteinuria, nephrotic syndrome (NS), and the development of complete and partial remissions (CR and PR), were assessed.RESULTS:MN was detected in 201 cases; the secondary etiology of the disease was established in 24.9%. The prevalence of MN among morphologically confirmed glomerulopathies was 14%; that of PMN was 10.4%. The median period to diagnosis PMN was 8 (5; 19) months. 150 patients with PMN (66.7% were men; age was 50±15 years) were distributed according to the following morphological stages: Stages I (23.9%), II (48.5%), III (26.1%), and IV (1.5%). Elevated anti-PLA2R Ab levels were found in 51.6% of cases; NS in the presence of proteinuria was detected in 85.6% of patients. An estimated glomerular filtration rate (eGFR) of <60 ml/min/1.73 m2 was seen in 25% of cases. Treatment outcomes were evaluated in 80 cases; the median follow-up period was 19 (8; 40) months. 68% of cases had CR (32%) or PR (36%) with a median follow-up of 26 (13; 44) months. Spontaneous CRs or PRs were observed in 7.5% of the patients. Multivariate analysis showed that the probability of CR or PR increased 3.2-fold in the use of cyclophosphamide and/or cyclosporine and decreased as eGFR dropped.CONCLUSION:In Russia, PMN is a common type of glomerulopathy, the specific features of which should include the low rates of spontaneous remissions and detection of anti-PLA2R Abs. For renal protection, the majority of patients with PMN require timely diagnosis and treatment; individualization of the choice of treatment and its enhanced efficiency call for further investigations.

AIM OF THE STUDY. It is traditionally believed that uromodulin (Umo) may participate in urinary stone formation. However, there is evidence that Umo can be operated in other mechanisms, especially damaging tubulointerstitial renal compartment and promotional arterial hypertension. In this regard, we attempt to compare the levels of the Umo in urine and blood serum with the morphological characteristics of kidney lesions and some clinical functional parameters in patients with various nephropathies. PATIENTS AND METHODS. Twenty eight patients (Pts; M:F 11:17) with various nephropathies, aged 28 – 74 years were examined. Everybody was performed renal biopsy with semi-quantitative assessment of renal injury severity using light-optic analysis. There were measured UMO, creatinine and urea levels in blood serum, UMO and protein concentration in urine, was estimated glomerular filtration rate (eGFR; CKD-EPI). In twenty Pts 24-hour blood pressure monitoring was performed. RESULTS. Urinary Umo concentration significantly inverse correlated (Spearmen rank correlation coefficient) with degree of tubular atrophy (TA; Rs=-0.39; P=0.038), mononuclear infiltration of interstitium (Rs=-0,37; P=0,05) and mean systolic BP at the day time (mSBPday; Rs=-0.49; P=0.028). Serum Umo concentration was directly associated with eGFR (Rs=0.53; P=0.007) and inverse with tubular Каюков И.Г. 197022, Санкт-Петербург, ул. Л. Толстого, д. 17, ПСПбГМУ им. акад. И.П. Павлова, корп. 54, тел.: (812) 346-39-26; e-mail: kvaka55@mail.ru

В.А. Добронравов1, Е.О. Богданова1, Н.Ю. Семенова5, О.Н. Береснева1, М.М. Парастаева1, О.В. Галкина1, И.М. Зубина1, Е.Е. Зуева3, Г.Т. Иванова1, И.Г. Каюков1, Т.Л. Коваленко3, Л.В. Котенко3, Г.М. Нутфуллина2, В.Г. Сиповский1, В.А. Цинзерлинг4, А.В. Смирнов1 ПОЧЕЧНАЯ ЭКСПРЕССИЯ БЕЛКА αKLOTHO, ФАКТОР РОСТА ФИБРОБЛАСТОВ 23 И ПАРАТИРЕОИДНЫЙ ГОРМОН ПРИ ЭКСПЕРИМЕНТАЛЬНОМ МОДЕЛИРОВАНИИ РАННИХ СТАДИЙ ХРОНИЧЕСКОГО ПОВРЕЖДЕНИЯ ПОЧЕК

AIM:To study an association between clinical and morphological evidence and the serum and daily urinary levels of cystatin C (CysC) and neutrophil gelatinase-associated lipocalin (NGAL) in patients with primary glomerulopathies.SUBJECTS AND METHODS:The investigation included 104 patients; morphological examination showed minimal change disease in 15 (14.4%) patients, focal segmental glomerulosclerosis in 24 (23.1%), membrane nephropathy in 32 (30.8%), and IgA nephropathy (mesangioproliferative glomerulonephritis) in 33 (31.7%). The investigators analyzed the clinical type of nephropathy, performed conventional laboratory and instrumental examinations, and determined the level of CysC (by immunoturbodimetry) and NGAL (by enzyme immunoassay) in the serum and daily urine taken before kidney biopsy. The degree of glomerulosclerosis, tubulointerstititial sclerosis, and tubular atrophy was semiquantitatively estimated.RESULTS:Urinary CysC and NGAL excretion correlated with the degree of glomerulosclerosis and proteinuria and the reduced glomerular filtration rate (GFR) regardless of the method of its determination. The urinary level of NGAL positively correlated with the degree of tubular atrophy. The GFR value determined from serum CysC and creatinine levels more precisely reflected the degree of glomerulosclerosis.CONCLUSION:The tubulointerstitial compartment in primary glomerulopathies should be determined not only by morphological changes, but also by tubular function parameters by estimating the urinary excretion of biomarkers. The urinary content of CysC reflects tubular epithelial dysfunction whereas that of NGAL also characterizes tubular atrophy. To estimate the degree of glomerulosclerosis, it is more preferable to use the GFR calculated from the blood concentrations of CysC and creatinine, by keeping in mind clinical findings (using Chronic Kidney Disease Epidemiology Collaboration formula, 2012).