Examination Of Renal Biopsies Research Articles

Progress in the Study of Diabetic Nephropathy Markers

Diabetic nephropathy (DN) is the principal consideration of end-stage diabetic nephropathy in China, second only to chronic glomerulonephritis. It is the most common complication of diabetes and the cause of death in diabetic patients. The clinical manifestations of DN are proteinuria, edema, hypertension, and progressive renal damage, and its continuous development can turn into nephrotic syndrome and uremia. It has been reported that urinary microalbumin, cystatin C and homocysteine are related to the diagnosis of renal diseases. In addition, pathological examination of renal biopsy, as the golden standard, plays a vital role in clinical diagnosis of DN. In the meantime, with the rise of biomarkers research, such as Genetic Markers, miRNAs and AGEs, we can evaluate the renal function of diabetic patients by detecting these markers as early as possible. Taking into account the above information, we focus on research advances in the association of microalbuminuria, urinary inhibitory C, serum homocysteine, renal biopsy and biomarkers with DN.

Development of a droplet digital PCR assay for the detection of BK polyomavirus.

The objective of this study was to establish a more sensitive and specific diagnostic method for detecting plasma BK polyomavirus (BKPyV) DNA load in patients after renal transplantation using droplet digital polymerase chain reaction (ddPCR) and to validate the methodology. The linear range, lower limit of detection, accuracy, precision, and specificity of the detection system were evaluated by using the WHO BKPyV standard (7.2 log10 IU/mL) as a reference, in accordance with the relevant documents of the Clinical and Laboratory Standards Institute. Plasma samples were collected from 74 renal transplantation patients with urinary BKPyV-DNA levels exceeding 7 log10 copies/mL. Quantitative PCR (qPCR) and ddPCR were performed, and their diagnostic efficacy for BKPyV-DNA in the diagnosis of BK polyomavirus-associated nephropathy was evaluated using a receiver operating characteristic (ROC) curve. The coefficients of variation for the repeated detection of BKPyV standard DNA were 2.55 and 4.71 at concentrations of 6.2 and 3.2 log10 IU/mL, respectively. The linear range was 2.2-6.2 log10 IU/mL, and the lowest detection limit was 100 IU/mL. By utilizing histopathological examination of renal biopsy as the gold standard for BKPyV diagnosis, the area under the ROC curve of 74 post-transplantation plasma samples detected by the ddPCR system was found to be 0.875 (95% CI: 0.797-0.953, P < 0.01). The optimal threshold was 512.86 copies/mL, with a sensitivity of 90.0% and a specificity of 67.6%. In comparison, the area under the ROC curve for qPCR was 0.668 (95% CI: 0.583-0.752, P < 0.01), with an optimal threshold of 11,481.54 copies/mL, a sensitivity of 35.0%, and a specificity of 100.0%. Pairwise comparison (Delong test) of the ROC curves of the two systems showed a significant difference in the area under the curve, with a difference of 0.207 and a P-value <0.01. The BKPyV nucleic acid detection system, based on ddPCR, is appropriate for the regular monitoring of the BK polyomavirus, specifically in plasma samples containing low viral DNA loads while it provides the benefits of both absolute quantification and high sensitivity.IMPORTANCEIt was previously believed that droplet digital polymerase chain reaction had limitations, including high cost, limited throughput, and cumbersome operation, which hindered its widespread application in clinical practice. However, the current fully automated digital PCR platform, combined with streamlined operations, can detect 96 samples at once, and the entire process can be completed within an hour, laying a solid foundation for its extensive use.

Introduction to renal pathology

In recent decades, nephropathology has developed worldwide as asubspeciality of pathology, which requires special methodological and technical equipment to process the material and specific clinical and pathological expertise to interpret the findings. These special requirements mean that nephropathology is not available at all pathology institutes, but is carried out on alarge scale in afew highly specialised centres. The history of nephropathology, or in anarrower sense the specialised histopathological examination of kidney biopsies, began in 1958 with the first use or performance of akidney biopsy [1]. It thus replaced the practice of urinalysis, which had been common since the Middle Ages, as adiagnostic tool for kidney diseases. Specialised techniques such as immunofluorescence or immunohistology but also electron microscopy are required to assess specific renal changes, for which the examination of renal biopsies is one of the few remaining routine applications today. In Germany and German-speaking countries, the discipline developed thanks to the work of outstanding people in the field of pathology who were primarily involved in this discipline and had the necessary technical and human resources in their laboratories to ensure that these biopsies could be analysed.

Data retrieval from archival renal biopsies using nonlinear microscopy.

Thorough examination of renal biopsies may improve understanding of renal disease. Imaging of renal biopsies with fluorescence nonlinear microscopy (NLM) and optical clearing enables three-dimensional (3D) visualization of pathology without microtome sectioning. Archival renal paraffin blocks from 12 patients were deparaffinized and stained with Hoechst and Eosin for fluorescent nuclear and cytoplasmic/stromal contrast, then optically cleared using benzyl alcohol benzyl benzoate (BABB). NLM images of entire biopsy fragments (thickness range 88-660 μm) were acquired using NLM with fluorescent signals mapped to an H&E color scale. Cysts, glomeruli, exudative lesions, and Kimmelstiel-Wilson nodules were segmented in 3D and their volumes, diameters, and percent composition could be obtained. The glomerular count on 3D NLM volumes was high indicating that archival blocks could be a vast tissue resource to enable larger-scale retrospective studies. Rapid optical clearing and NLM imaging enables more thorough biopsy examination and is a promising technique for analysis of archival paraffin blocks.

Risk Factors and Causality of Early Graft Loss in Kidney Transplanted Patients in Northwestern Iran: A 10-Year Retrospective Study

Background: Early graft loss (EGL) is one of the rare complications of kidney transplantation. Several factors play a role in the occurrence of EGL in kidney transplant recipients, which must be identified and limited. Objectives: This ten-year retrospective study was conducted in a single center on 32 kidney transplant recipients with EGL to determine the reasons for and risk factors of kidney transplant rejection in Iran. Methods: This descriptive-analytical study’s population included 605 kidney transplant recipients receiving kidneys during the last ten years in our center. The diagnosis of EGL was based on renal allograft biopsy examination and primary clinical complications, including a rapid increase in serum creatinine. The age, gender, blood group, and rhesus (Rh) of both donors and recipients, as well as the kinship between the donor and recipient (relative and non-relative), right/left-sided living donor/recipient kidneys, primary kidney disease, the presence of underlying disease in the recipient, dialysis duration, the year of kidney transplantation, transplant survival time, patient survival time, and complications (surgery and others) were gathered. The data were analyzed using SPSS version 18. Results: In this study, 32 out of 605 kidney transplant recipients (5.28%) experienced EGL (53.1% male and 46.9% female, average age of 41.12 years). The duration of kidney function after transplantation was 5.56 ± 0.13 days. The transplanted kidneys were functional between 72 hours and one week after transplantation in 34.4% of the patients. The causes of EGL were found to be tissue rejection in 31.3% of the patients and vascular thrombosis and hyperacute rejection in 21.8%. Nephrectomy occurred in 41% of the patients, and 43.75% died because of a heart attack. Conclusions: Our findings supported previous studies' results, suggesting that EGL is associated with receiving an incompatible kidney transplant and surgery-related complications, including bleeding and thrombosis.

#6323 RENAL CONTRAST-ENHANCED ULTRASOUND AND GLOMERULONEPHRITIS: A GOOD MARKER OF DISEASE ACTIVITY

Abstract Background Contrast-enhanced ultrasound (CEUS) could provide a lot of information of renal blood flow. Renal blood flow is an excellent marker of inflammatory and fibrotic processes in the kidney such as glomerulonephritis. Therefore, in patients with these diseases, renal CEUS can be both a prognostic marker and an index of response to therapy. Currently in the literature there are preliminary studies showing the role of CEUS in terms of histology and outcome in the evaluation of patients with glomerulonephritis. In this pilot study we used perfusion CEUS parameters (WiR and WoR; WiAUC and WoAUC) as possible markers of renal microvascular damage. We compared the perfusion parameters with the clinical and histological findings of our patients. Method Eighteen patients with clinical and laboratory signs of glomerulonephritis were enrolled. All patients underwent ultrasound-assisted renal biopsy and B-mode ultrasound examination, color Doppler ultrasound and contrast-enhanced ultrasound. Time Intensity (TI) curves were obtained from renal CEUS. TI curves and several quantitative perfusion parameters were defined using VueBox® Quantitation Software. Results From April to October 2022, 18 patients (12 men and 6 women) with clinical and laboratory suspicion of glomerular disease were enrolled. Median age was 48.05 years, all patients underwent renal biopsy and contrast-enhanced ultrasound at basal condition. Table 1 shows patients characteristics. CKD patients were stratified into two groups according to their eGFR: group I (eGFR &amp;lt; 60 ml/min/1.73 m2, n. = 4) and group II (eGFR ≥ 60 ml/min/1.73 m2, n. = 3). Moreover, we divided patients into two groups based on the presence of nephrotic-range proteinuria (≥ 3.5 g/24h). At this time, seven patient data are suitable for analysis. The small sample size at present does not allow for statistical significance. However, in our study, the persistence of contrast agent signal during the wash-out phase was differed markedly in correlation with the degree of CKD. In particular, we observed a slower wash-in phase in the presence of vascular hyalinosis (Fig. 1). Conclusion Our experience seems to confirm that CEUS parameters can be excellent indicators both in terms of patient disease outcomes and histological data. CEUS can effectively and quantitatively demonstrate renal microvascular perfusion in patients with glomerulonephritis. Future goal is that CEUS could also be a prognostic and follow-up marker after renal biopsy in patients with glomerulonephritis.

Renal Involvement of Immunoglobulin G4-Related Disease Presenting as a Solitary Hypermetabolic Mass Mimicking Renal Tumor on 18F-FDG PET/CT.

A 62-year-old woman with a 5-year history of diabetes insipidus was found with a solitary renal mass in contrast-enhanced CT. 18F-FDG PET/CT showed a hypermetabolic mass in the right kidney. Besides, there was increased uptake in the pituitary stalk. The histopathological examination of renal biopsy confirmed the diagnosis of immunoglobulin G4-related disease. After treatment with prednisone and cyclophosphamide, there was obvious radiographic improvement of the renal lesion.

Development of monoclonal antibodies and antigens as liquid biopsy reagents for IgA nephropathy

Abstract IgA nephropathy (IgAN) is the most common primary autoimmune glomerular disorder across the world. A renal biopsy examination is absolutely required for final diagnosis. In particular, IgAN has been categorized as an autoimmune disease that features IgA-ICs formed by galactose-deficient (Gd)-IgA1 (autoantigen) and corresponding IgG anti-Gd-IgA1 (autoantibody). Therefore, it is clinically warranted to develop a liquid kidney biopsy for non-invasive or only minimally invasive approaches for early diagnosis of IgAN and to ease monitoring the evolution of the disease. We have recently developed three monoclonal antibodies namely EASON1, EASON2, and EASON3, and each of them shows high discriminative rate in differentiating IgAN patients and healthy control subjects by doing ELISA-based analyses to determine serum Gd-IgA1 levels (Provisional patent - T2392-US, USAentitled “Production of IgG monoclonal antibody series anti-galactose deficient IgA1 and IgA1 bearing O-linked glycans; Provisional patent - 63/119,215, USAentitled “Development of a series of IgM monoclonal antibodies as non-invasive diagnostic reagents for IgA nephropathy; a regular patent application under review). Moreover, we have successfully developed 62 human hybridoma cell lines that produce Gd-IgA1, each of which will be useful in designing tests for the detection of serum IgG autoantibodies against Gd-IgA1 levels (Provisional patent - T2392-US, USA). In conclusion, both the 3 mouse monoclonal antibodies and 62 human Gd-IgA1-producing hybridoma cell lines may be further developed as promising diagnostic reagents for a liquid kidney biopsy for IgAN, allowing for early, rapid, and non-invasive tests for the renal disease. Supported by grants from Ministry of Science and Technology, Taiwan (MOST 108-2321-B-016-002, 109-2314-B-016 -034 -MY3)

IgG4-related disease with kidney and lymph nodes involvement: a case-based review.

IgG4-related disease (IgG4-RD), a rare immune-mediated chronic fibro-inflammatory condition, has various initial symptoms, thus posing diagnostic and therapeutic challenges. Here, we report a case of IgG4-RD in a 35-year-old man with initial clinical symptoms of facial edema and recent onset of proteinuria. It took more than 1year from the onset of clinical symptoms to diagnosis. Pathological examination of renal biopsy revealed significant renal interstitial lymphoid tissue hyperplasia simulating growth pattern of lymphoma. Immunohistochemical (IHC) staining results showed that CD4 + T lymphocyte hyperplasia was dominant. There was no significant deletion of CD2/CD3/CD5/CD7. No monoclone was detected in TCR gene rearrangement. IHC staining showed that the number of IgG4-positive cells was greater than 100/HPF. The ratio of IgG4/IgG was greater than 40%. Combined with clinically examinations, IgG4-related tubulointerstitial nephritis was considered. Further cervical lymph node biopsy results suggested IgG4-related lymphadenopathy. He received methylprednisolone 40mg/day intravenously for 10days, leading to normal results of laboratory tests and clinical manifestations. The patient had a good prognosis without recurrence during 14months of follow-up. This case report can be used as a reference for early diagnosis and treatment of such patients in the future.

IgA-dominant glomerulonephritis with DNAJB9-negative fibrillar polytypic immunoglobulin deposits in the subepithelium.

Fibrillary glomerulonephritis (FGN), a rare disease is pathologically characterized by glomerular fibril accumulation ranging from 12 to 24nm in diameter with negative Congo red staining. Recently, the identification of DnaJ homolog subfamily B member 9 (DNAJB9) as a highly sensitive and specific marker for FGN has revolutionized diagnosis of this disease. However, few recent studies have reported DNAJB9-negative glomerulonephritis with fibrillar deposits. As such, it remains unclear whether DNAJB9-negative cases can be considered equivalent to FGN. Here, we report the case of a 70-year-old woman who developed renal impairment and nephrotic-range proteinuria. Renal biopsy and pathological examination revealed focal glomerulonephritis with fibrocellular crescents. Immunofluorescence microscopy showed IgA-dominant deposition of polytypic IgG in the glomerulus. Electron microscopy revealed hump-like subepithelial electron dense deposits with fibrils of 15-25nm in diameter. These findings were consistent with FGN; thus, Congo red and direct fast scarlet (DFS) staining, and immunohistochemistry for DNAJB9 were performed. In addition to negative Congo red/DFS/DNAJB9 staining, laser microdissection (LMD) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) resulted negative for DNAJB9, which is a highly sensitive and specific marker for FGN. The patient's renal function further declined, prompting administration of rituximab weekly for 2weeks, similar to the treatment for FGN. This is a unique case of IgA-dominant glomerulonephritis with DNAJB9-negative fibrillar polytypic immunoglobulin deposits in the subepithelium, unlike previous DNAJB9-negative cases. Thus, DNAJB9-negative cases diagnosed based on accurate electron microscopic evaluation must be gathered, and LMD and LC-MS/MS must be used to analyze the organized fibrillar deposits to reveal the disease entity.

A Case of Monoclonal Immunoglobulin Deposition Disease – on Bortezomib regimen, A Novel strategy in Multisystemic Involvement

Background: Monoclonal immunoglobulin deposition disease (MIDD) is a rare and sporadic phenomenon often manifesting in individuals who are in their 5th – 6th decade of life. MIDD along with restrictive cardiomyopathy and Renal AL amyloidosis as in the present case is also an unaccustomed phenomenon. Often, the patient presents with unusual symptoms and is more prone to misdiagnosis. The congo red (-) deposition of the monoclonal light chain can be frequently noted in multiple organs including the heart and kidney. The light chain deposition can be either isolated lambda or gamma chain and they are classified accordingly. While serum electrophoresis at an early presentation may reveal underlying monoclonal gammopathy, the immunofluorescence and histopathological examination of renal biopsy remain the mainstay diagnostic tool. Objective: The case study was done because of its uniqueness in the usage of a novel strategy in the treatment of MIDD. Results: In the current case, a 52-year-old male presented with chest pain and NYHA grade 3 dyspnea for 8 days along with bilateral lower limb pitting oedema since 3 months. In certain prevailing situations, a patient can be misdiagnosed with ischemic heart disease or acute on chronic renal failure. However, detailed history and time-bound investigation will act as a safeguard. Conclusion: When patients have no co-morbidities and no addictions, and the patient’s investigation reveals heavy proteinuria, the rheumatological and haematological etiologies must be ruled out to establish a final diagnosis for timely treatment. As in our case, the rheumatological work-up was negative but we found an M band spike on serum electrophoresis, which expedited our search for underlying plasma-cell dyscrasia.

The clinical and pathological relevance of waxy casts in urine sediment

Although casts in urine may imply the underlying pathogenesis and the diagnosis, the waxy cast is poorly understood yet. We aim to investigate the association between waxy casts and clinicopathological indices. Patients undergone renal biopsy and urine sediment examination were enrolled. Waxy casts referred to those presented with a homogeneous melted wax appearance and pre-waxy casts referred to those in which one or more segments demonstrated a waxy-cast appearance. Multivariable logistic regression was used to assess the factors associated with waxy casts. In 1282 patients, the detection rate of waxy casts was 26.3%. If either waxy or pre-waxy cast was considered as a diagnostic marker for renal insufficiency (eGFR < 60 ml/min/1.73 m2), the sensitivity was 0.58 and the specificity was 0.88. If the only waxy cast was considered as the diagnostic marker, the sensitivity was 0.29 and the specificity was 0.97. The patients with waxy or pre-waxy casts had higher blood pressure, more proteinuria, and worse renal function. Waxy or pre-waxy cast was independently associated with eGFR (odds ratio: 0.73 per 10 mL/min/1.73 m2 increase, 95% confidence interval: 0.69–0.77, p < 0.001), proteinuria (odds ratio: 1.07 per 1 g/day increase, 95% confidence interval: 1.03–1.10, p < 0.001) and pathological lesions. Waxy or pre-waxy casts are closely related to impaired renal function. Their presence is a specific indicator of renal insufficiency but is not sensitive enough.

Electron microscopy in renal pathology: overall applications and guidelines for tissue, collection, preparation, and stains

ABSTRACT Electron microscopy is a mainstay in the analysis of renal biopsies, where it is typically employed in a correlative fashion along with light and immunofluorescence microscopy. Despite the development of a growing armamentarium of molecular and biochemical analytic methods as well as new immunostains with a widening panel of immunoreactants, electron microscopy remains crucial to the diagnosis of a number of disorders involving the renal glomerulus, vasculature, and tubulointerstitial compartment. The number of renal biopsies continues to grow and the indications for these biopsies continue expanding together with our understanding of disease processes. Proper collection of biopsies and careful analysis of data emanating from diagnostic modalities, clinical information, imaging, gross and microscopic tissue analysis, including a wide range of ancillary studies, represent the essential paradigm for generating detailed diagnoses with clinical significance. This communication offers a guide to the pre-analytic and analytic process for renal biopsy examination, discusses diagnostic keys and pitfalls for an important category of renal diseases (immune complex disorders), and provides an introduction to a useful adjunct diagnostic method (ultrastructural immunolabeling). Renal pathologists should render expert diagnoses that guide patient management, provide prognostic information and lead to targeted new therapeutic interventions that are currently available.

P0354MATRIX ASSISTED LASER DESORPTION/IONIZATION MASS SPECTROMETRY IN PROTEIN ALTERATIONS ASSOCIATED WITH THE PROGRESSION OF IGA NEPHROPATHY DISCOVERY

Abstract Background and Aims IgA nephropathy (IgAN) is one of the most diffuse glomerulonephrites worldwide, but there are still many issues regarding its prognosis and pathogenesis understanding. Although the diagnosis is established by renal biopsy examination, there are still remaining pitfalls in primary origin discrimination, and therefore for prognosis and outcome for the patient. Method In this pilot study we performed matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI) with a high spatial resolution (raster sampling of 20 μm) on formalin fixed paraffin embedded renal biopsies obtained from patients with IgAN (n=11) and other mesangioproliferative glomerulonephrites (MesPGN, n=6) attempting to enlighten proteomic alterations that may be associated with the progression of IgAN. The patients in both disease groups were separated according to their CKD stage (CKDI, CKDII, CKDIII and more). After MALDI-MSI analysis, all biopsies were stained with hematoxylin and eosin, scanned and overlaid with molecular image in order to verify the signals’ spatial distribution. Results Using MALDI-MSI we detected clear differences in the proteomic profiles of IgAN and other MesPGN tissues. Fourteen signals (AUC ≥ 0.8) were observed to have an altered intensity among the different CKD stages within the IgAN group. In particular, large increases in the intensity of these signals could be observed at CKD stages II and above. Putatively identified, these signals primarily corresponded to proteins involved in inflammatory and healing pathways and their increased intensity was localised within regions of tissue with large amounts of inflammatory cells or sclerosis (Figure 1), verified by immunohistochemical staining (Figure 2). Conclusion The capability of MALDI-MSI to provide highly spatially resolved proteomics analysis of complex renal tissue demonstrates it a useful additional diagnostic and prognostic tool and a promising approach in the search for prognostic or predictive markers in glomerular diseases.

The Spectrum of Glomerular Diseases in Mashhad According to Kidney Biopsy Records.

Introduction Knowing the national statistics of glomerular diseases will help in the management and minimizing their burden in the community. The aim of this study was to assess the overall distribution of subtypes of glomerulonephritis (GN) and the prevalence of renal diseases in a subgroup of diabetic and hypertensive patients. Methods This cross-sectional study was conducted on 860 patients with different subtypes of GN diagnosed by percutaneous renal biopsy and histological examination. Results The most common subtype of GN was membranous GN (30.1%) followed by minimal change disease (20.1%), IgA nephropathy (9.5%) and Lupus nephritis (8.8%), as well as membranoproliferative GN (6.4%), focal segmental GN (5.6%), crescent GN (43, 5%), and DM nephropathy (36, 4.2%). IgA nephropathy and focal segmental GN were mostly common among maleswhile the most female dominant GN was Lupus nephritis. Lupus nephritis was the most common GN diagnosis among subjects who were younger than 29 years old (50%), while the diabetic nephropathy was the most common GN diagnosis among subjects who were older than 53 years old (44.4%). The most common GN among hypertensive subgroups was focal segmental GN (41.7%) followed by diabetic nephropathy (33.3%) whereas the most common subtypes of GN among diabetics was diabetic nephropathy. Conclusion The most common type of GN among Iranian population in Mashhadwas membranous GN and minimal change disease. The distribution of each subtype of glomerular disease depend on the baseline determinants including age, gender and hypertensive state.

Glomerular Diseases in Patients with Diabetes Mellitus: An Underappreciated Epidemic.

The prevalence of nondiabetic kidney disease (NDKD) in patients with diabetes reflects the rising incidence of diabetes in the general population. The most current national prevalence of diabetes in United States adults is at a high of 12.2%. A contributing factor is the obesity epidemic, as 87.5% of diabetic adults are overweight or obese. It is well known that CKD and ESKD cause significant morbidity and mortality in obese and diabetic populations, with an estimated 36.5% of diabetics experiencing CKD (1). The relative risk of ESKD is higher in diabetics, ranging from 6.2 in white populations to 62.0 in Native Americans; of patients who start RRT, 51% are estimated to have diabetes (2). The diagnosis of diabetic kidney disease (DKD) is most often made clinically. However, there is growing awareness of the prevalence of NDKD with or without concomitant diabetic nephropathy (DN) in patients with diabetes. In turn, a large proportion of NDKD found on kidney biopsies is glomerular diseases. This knowledge draws attention to the possibility of undiagnosed, potentially reversible lesions in this population. Here, we review the prevalence and presentation of NDKD in diabetic patients, with a focus on glomerular lesions, and discuss the ways in which diabetes can affect the diagnosis and management of these conditions. A review of native kidney biopsies for evidence of NDKD in diabetics performed at the Columbia Renal Pathology Laboratory in 2011 estimated that 23.5% of patients with native kidney biopsies carry a diagnosis of diabetes, roughly double the prevalence of diabetes in United States adults. Of those patients, 37% had DN alone, 36% had NDKD alone, and 27% had concomitant DN and NDKD (3). A retrospective examination of renal biopsies at the Southern California Permanente Medical Group between 1995 and 2005 found larger proportions of patients with NDKD alone (53.2%) …

Matrix-assisted laser desorption/ionization mass spectrometry imaging to uncover protein alterations associated with the progression of IgA nephropathy.

IgA nephropathy (IgAN) is one of the most diffuse glomerulonephrites worldwide, and many issues still remain regarding our understanding of its pathogenesis. The disease is diagnosed by renal biopsy examination, but potential pitfalls still persist with regard to discriminating its primary origin and, as a result, determining patient outcome remains challenging. In this pilot study, matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI) was performed on renal biopsies obtained from patients with IgAN (n = 11) and other mesangioproliferative glomerulonephrites (MesPGN, n = 6) in order to enlighten proteomic alterations that may be associated with the progression of IgAN. Differences in the proteomic profiles of IgAN and MesPGN tissue could clearly be detected using this approach and, furthermore, 14 signals (AUC ≥ 0.8) were observed to have an altered intensity among the different CKD stages within the IgAN group. In particular, large increases in the intensity of these signals could be observed at CKD stages II and above. These signals primarily corresponded to proteins involved in either inflammatory and healing pathways and their increased intensity was localized within regions of tissue with large amounts of inflammatory cells or sclerosis. Despite much work in recent years, our molecular understanding of IgAN progression remains incomplete. This pilot study represents a promising starting point in the search for novel protein markers that can assist clinicians in better understanding the pathogenesis of IgAN and highlighting those patients who may progress to end-stage renal disease.

SUN-109 THE ROLE OF SHEAR WAVE ELASTOGRAPHY IN EVALUATING CHRONIC ALLOGRAFT INJURY AND SUBCLINICAL REJECTION

Subclinical rejection (SCR) has been identified contributing to chronic allograft injury and subsequent graft loss after kidney transplantation. Studies have shown SCR to be associated with chronic tubulointerstitial damage. To date, histologic examination of renal allograft biopsy remained as gold standard to diagnosed SCR. However, it is invasive and has a substantial risk of bleeding. Shear wave elastography (SWE) is an emerging non-invasive ultrasound technique that measures tissue stiffness.

Apoptosis as a mechanism of the albumin-induced kidney damage in childhood nephrotic syndrome

It was shown previously on in vivo studies that proteinuria-induced effects play a crucial role in renal damage in chronic kidney disease (CKD). However, an initial mechanism of irreversible kidney damage in pediatric diseases characterized by chronic proteinuria, i.e. nephrotic syndrome, remains to be unclear. &#x0D; The aim of our work was to study the initial mechanism of kidney cells apoptosis development in nephrotic children. &#x0D; Methods.An examination of renal biopsies of 53 patients (aged 10 to 15 years) with nephrotic syndrome hospitalized in Pediatric Nephrology unit of the Children Clinical Hospital №7 (Kyiv, Ukraine) done. In vitro studies of albumin toxicity performed on rat proximal tubular cells in primary culture (RPTC). &#x0D; Results. Our study showed that albumin overload in nephrotic children leads to high levels of apoptosis. Its distribution and level varies regarding the level of focal segmental glomerulosclerosis (FSGS). The progression of sclerosis as a sign of irreversible kidney damage is accompanied by gradual increase in expression of proapoptotic factor Bax. &#x0D; In vitro studies on rat proximal tubular cells in primary culture (RPTC) showed that excessive albumin uptake into rat primary renal cells causes an almost immediate mitochondrial accumulation of the apoptotic factor Bax. We hypothesize that this might be initial pathway leading to kidney cells apoptosis in childhood nephrotic syndrome. &#x0D; Conclusions. We show thatoverexpression of apoptotic factor Bax has a place in children with nephrotic syndrome. Thus, chronic influence of albumin is a factor predisposing disturbances in system controlling apoptosis in this cohort of patients. Our data demonstrate that there is a dependence between the Bax overexpression level and the stage of CKD. We show the topologic difference between the Bax levels and FSGS degree. This is an indication thatdevelopment of glomerular and tubule-interstitial disorders under the influence of proteinuria occurs in specific range. In vitro data demonstrate that albumin overload causes mitochondrial Bax translocation that could be an initial factor in apoptotic pathway activation.

BK Nephropathy in Renal Transplant Patients with Epididymo-Orchitis

: The patient was a 10-year-old male that was transplanted six months prior to this study. He was admitted because of epididymo-orchitis, pyuria, glucosuria, and rising blood urea nitrogen (BUN) and creatinine (Cr). BK viruria copy number was 50,000,000. In renal biopsy examination, acute cellular rejection was reported. The diagnosis was BK virus epididymo orchitis with BK allograft nephropathy. His treatment was started by discontinuation of tacrolimus and mycophenolate and starting of leflunomide and low dose prednisolone. After improvement of renal dysfunction and BK load, the treatment regimen was changed to cyclosporine and sirolimus. Renal function after the one-year follow up did not change and remained in a good condition.