Recognition of intraglomerular histological features with deep learning in protocol transplant biopsies and their association with kidney function and prognosis

Background

The Banff Classification may not adequately address protocol transplant biopsies categorized as normal in patients experiencing unexplained graft function deterioration. This study seeks to employ convolutional neural networks to automate the segmentation of glomerular cells and capillaries and assess their correlation with transplant function.

Methods

A total of 215 patients were categorized into three groups. In the Training cohort, glomerular cells and capillaries from 37 patients were manually annotated to train the networks. The Test cohort (24 patients) compared manual annotations vs automated predictions, while the Application cohort (154 protocol transplant biopsies) examined predicted factors in relation to kidney function and prognosis.

Results

In the Test cohort, the networks recognized histological structures with Precision, Recall, F-score and Intersection Over Union exceeding 0.92, 0.85, 0.89 and 0.74, respectively. Univariate analysis revealed associations between the estimated glomerular filtration rate (eGFR) at biopsy and relative endothelial area (r = 0.19, P = .027), endothelial cell density (r = 0.20, P = .017), mean parietal epithelial cell area (r = -0.38, P < .001), parietal epithelial cell density (r = 0.29, P < .001) and mesangial cell density (r = 0.22, P = .010). Multivariate analysis retained only endothelial cell density as associated with eGFR (Beta = 0.13, P = .040). Endothelial cell density (r = -0.22, P = .010) and mean podocyte area (r = 0.21, P = .016) were linked to proteinuria at biopsy. Over 44 ± 29 months, 25 patients (16%) reached the primary composite endpoint (dialysis initiation, or 30% eGFR sustained decline), with relative endothelial area, mean endothelial cell area and parietal epithelial cell density below medians linked to this endpoint [hazard ratios, respectively, of 2.63 (P = .048), 2.60 (P = .039) and 3.23 (P = .019)].

Conclusion

This study automated the measurement of intraglomerular cells and capillaries. Our results suggest that the precise segmentation of endothelial and epithelial cells may serve as a potential future marker for the risk of graft loss.

Kidney Veno-Muscular Characteristics and Kidney Disease Progression: A Native Kidney-Biopsy Study

Rationale & Objective

Assessment of kidney biopsies provides crucial information for diagnosis and disease activity, as well as prognostic value. Kidney-biopsy specimens occasionally contain veno-muscular complex (VMC), which consists of muscle tissues around the kidney venous system in the corticomedullary region. However, the role of VMC and the clinical significance of VMC variants are poorly understood. In the present study, we investigated kidney prognostic values of VMC variants.

Study Design

Retrospective cohort study.

Setting & Participants

Among 808 patients who underwent a kidney biopsy from 2011 to 2019, 246 patients whose kidney biopsy specimens contained VMC were enrolled.

Predictors

VMC variants; inflammatory-VMC (an infiltration of ≥80 inflammatory cells/mm2-VMC area) and VMC hypertrophy (hyper-VMC, a VMC average width ≥850 μm), and the interstitial fibrosis/tubular atrophy (IFTA) score.

Outcomes

A decline in estimated glomerular filtration rate (eGFR) ≥40% from the baseline or commencement of kidney replacement therapy.

Analytical Approach

Cox proportional hazards model.

Results

Among 246 patients with data on VMC, mean baseline eGFR was 56.0±25.6 ml/min per 1.73 m2; 80 had high inflammatory-VMC, and 62 had VMC hypertrophy. There were 51 kidney events over median follow-up of 2.5 years. We analyzed 2 VMC variants. Multivariable logistic regression analysis revealed that eGFR negatively correlated with the presence of both inflammatory-VMC and hyper-VMC. A Cox proportional hazards analysis revealed that inflammatory-VMC (but not hyper-VMC) was independently associated with the primary outcome after adjustments for known risk factors of progression, including proteinuria, eGFR, and the interstitial fibrosis/tubular atrophy (IFTA) score (hazard ratio, 1.97; 95% confidence interval, 1.00-3.91).

Limitations

Single-center study and small sample size.

Conclusions

Assessment of inflammatory-VMC provides additional kidney prognostic information to known indicators of kidney disease progression in patients who undergo kidney biopsy.

Plain-Language Summary

Assessment of kidney biopsies provides crucial information for diagnosis, disease activity, and prognostic value. Kidney-biopsy specimens occasionally contain veno-muscular complex (VMC), which consists of muscle tissues around the kidney venous system. Currently, the role of VMC in kidney health and diseases and the clinical significance of VMC variants are poorly understood. In the present study, we have shown that an infiltration of ≥80 inflammatory cells/mm2-VMC area (inflammatory-VMC) is independently associated with kidney disease progression after adjustments for known risk factors of progression. Therefore, assessment of inflammatory-VMC provides additional kidney prognostic information to known indicators of kidney disease progression in patients who undergo kidney biopsy.

Accurate Kidney Pathological Image Classification Method Based on Deep Learning and Multi-Modal Fusion Method with Application to Membranous Nephropathy

Membranous nephropathy is one of the most prevalent conditions responsible for nephrotic syndrome in adults. It is clinically nonspecific and mainly diagnosed by kidney biopsy pathology, with three prevalent techniques: light microscopy, electron microscopy, and immunofluorescence microscopy. Manual observation of glomeruli one by one under the microscope is very time-consuming, and there are certain differences in the observation results between physicians. This study makes use of whole-slide images scanned by a light microscope as well as immunofluorescence images to classify patients with membranous nephropathy. The framework mainly includes a glomerular segmentation module, a confidence coefficient extraction module, and a multi-modal fusion module. This framework first identifies and segments the glomerulus from whole-slide images and immunofluorescence images, and then a glomerular classifier is trained to extract the features of each glomerulus. The results are then combined to produce the final diagnosis. The results of the experiments show that the F1-score of image classification results obtained by combining two kinds of features, which can reach 97.32%, is higher than those obtained by using only light-microscopy-observed images or immunofluorescent images, which reach 92.76% and 93.20%, respectively. Experiments demonstrate that considering both WSIs and immunofluorescence images is effective in improving the diagnosis of membranous nephropathy.

Automated scoring of total inflammation in renal allograft biopsies

BACKGROUND

Computer-assisted scoring is gaining prominence in the evaluation of renal histology; however, much of the focus has been on identifying larger objects such as glomeruli. Total inflammation impacts graft outcome, and its quantification requires tools to identify objects at the cellular level or smaller. The goal of the current study was to use CD45 stained slides coupled with image analysis tools to quantify the amount of non-glomerular inflammation within the cortex.

METHODS

Sixty renal transplant whole slide images were used for digital image analysis. Multiple thresholding methods using pixel intensity and object size were used to identify inflammation in the cortex. Additionally, convolutional neural networks were used to separate glomeruli from other objects in the cortex. This combined measure of inflammation was then correlated with rescored Banff total inflammation classification and outcomes.

RESULTS

Identification of glomeruli on biopsies had high fidelity (mean pixelwise dice coefficient of .858). Continuous total inflammation scores correlated well with Banff rescoring (maximum Pearson correlation .824). A separate set of thresholds resulted in a significant correlation with alloimmune graft loss.

CONCLUSIONS

Automated scoring of inflammation showed a high correlation with Banff scoring. Digital image analysis provides a powerful tool for analysis of renal pathology, not only because it is reproducible and can be automated, but also because it provides much more granular data for studies.

Detectable serum IgM monoclonal gammopathy in non-hepatitis-associated mixed cryoglobulinemic glomerulonephritis: A case report and literature review

Cryoglobulinemia is the presence of circulating cryoglobulin which can cause systemic vasculitis and glomerulonephritis. Monoclonal gammopathy of renal significance is strongly associated with type I cryoglobulinemia, but the role of detectable serum monoclonal gammopathy in mixed (type II) cryoglobulinemia is not clearly established. We report a case of a 71-year-old woman who presented with skin rash, leg edema, and azotemia. Investigations showed a positive result for rheumatoid factor, low complement C4 level, positive result for serum cryoglobulin, and positive M-spike on serum protein electrophoresis and IgM kappa monoclonal gammopathy on serum immunofixation. Kidney biopsy revealed membranoproliferative glomerulonephritis, polytypic IgM-dominant deposits in an immunofluorescence study, and microtubular substructures in an electron microscopic study. After an extensive workup, no evidence of myeloma or lymphoma was found. A diagnosis of monoclonal gammopathy of renal significance-associated mixed cryoglobulinemic glomerulonephritis was made. Due to the detectable IgM kappa monoclonal gammopathy in the patient's serum, clonal-directed therapy was administered. The patient had been in clinical remission after treatment with clone-directed therapy with cyclophosphamide and steroids. The literature review for cases of type II cryoglobulinemic glomerulonephritis that have detectable serum monoclonal gammopathy are summarized in this study.

Characteristics of disease distribution for the 1 370 renal biopsy cases in two hospitals from Guilin and Jining

OBJECTIVES

To analyze the constitution and distribution characteristics of renal pathological disease spectrum in the 2 hospitals from Guilin city and Jining city in recent 5 years.

METHODS

The pathological results of inpatients with renal biopsy in the 2 hospitals from Guilin city and Jining city from April 1, 2014 to August 15, 2018 were retrospectively analyzed. A total of 1 370 renal biopsy cases were collected, including 706 cases in Affiliated Hospital of Jining Medical College (Jiyi) and 664 cases in Affiliated Hospital of Guilin Medical College (Guiyi).

RESULTS

There was no significant difference in gender, age, seasonal distribution and the total proportion of primary and secondary glomerular diseases between the 2 hospitals (all P>0.05). The ratio of male to female in the 2 hospitals was 1.18 (Jiyi) and 0.98 (Guiyi). IgA nephropathy (IgAN) was the major disease in 14-30 years old patients, and membranous nephropathy (MN) was the most common in 40-50 years old patients. There are 15 kinds of same diseases and 10 kinds of different diseases in the 2 hospitals. Among them, three pathological diseases (3 cases) including obesity-related nephropathy, primary Sjogren's syndrome renal damage, and pregnancy-induced hypertensive renal damage only appeared in Jiyi, while 7 diseases (55 cases) including focal segmental glomerulosclerosis (FSGS), focal proliferative glomerulonephritis (FGN), proliferative sclerosing glomerulonephritis (PSGN), endocapillary proliferative glomerulonephritis (EPGN), multiple myeloma renal damage, eosinophilic tumor renal damage and angiomyolipoma renal damage only appeared in Guiyi. Primary glomerular diseases (82% in Jiyi/79% in Guiyi) were higher than secondary nephropathy. The top two diseases in biopsy rate were MN and IgAN. The incidence rate of some diseases in Jiyi was higher than that in Guiyi, and these diseases included MN (48.87%, 31.78%), minimal change disease (MCD) (11.47%, 2.71%), allergic purpura nephritis (Henoch-Schlein purpura nephritis, HSPN) (3.97%, 1.51%), hypertensive renal damage (3.12%, 0.15%), diabetic nephropathy (DN) (2.97%, 1.36%). The incidence rate of other diseases in Guiyi were higher than that in Jiyi, and these diseases included IgAN (22.59%, 19.14%), mesangial proliferative glomerulonephritis (MsPGN) (11.45%, 0.99%), lupus nephritis (LN) (8.58%, 4.67%), hepatitis B virus associated nephritis (HBVGN) (7.53%, 1.84%), there were significant difference between the 2 hospitals in the above diseases (all P<0.05).

CONCLUSIONS

The disease distribution of renal biopsy cases in the 2 hospitals displays both similarities and characteristics. Primary glomerular disease is still the main disease. MN has surpassed IgAN and jumped to the first place. The high incidence age of MN is 40-50 years old, and IgAN is 14-30 years old. The incidence rates of MN, MCD, HSPN, hypertensive renal damage, DN and other related diseases of air quality and lifestyle in Jiyi are higher than those in Guiyi. IgAN, MsPGN, LN, HBVGN and other diseases related to infection and tumor factors were higher in Guiyi than those in Jiyi. The prevention and control strategies in the 2 regions need to be adapted to local conditions. More attention should be paid to the impact of environment and lifestyle on kidney health in East China. We should pay attention to the damage to kidney caused by infectious diseases in Southern China, especially in female patients.

Lipoic acid supplementation associated with neural epidermal growth factor-like 1 (NELL1)-associated membranous nephropathy

Lipoic acid (alpha lipoic acid, thioctic acid) is a popular over-the-counter antioxidant and insulin-mimetic supplement under investigation in a variety of conditions including multiple sclerosis, diabetes, and schizophrenia. Unfortunately, high-grade proteinuria was an unexpected adverse event specific to the treatment arm of our clinical trial investigating lipoic acid supplementation in patients with multiple sclerosis. This observation led to detection of similar patients in our nephrology practice. Here, we describe four biopsy-proven cases of neural epidermal growth factor-like 1 (NELL1)-associated membranous nephropathy following lipoic acid supplementation and a fifth suspected case. Discontinuation of lipoic acid and supportive therapy resulted in remission.

Opisthorchis viverrini Infection Induces Metabolic and Fecal Microbial Disturbances in Association with Liver and Kidney Pathologies in Hamsters

Opisthorchis viverrini (Ov) infection causes hepatobiliary diseases and is a major risk factor for cholangiocarcinoma. While several omics approaches have been employed to understand the pathogenesis of opisthorchiasis, effects of Ov infection on the host systemic metabolism and fecal microbiota have not been fully explored. Here, we used a ¹H NMR spectroscopy-based metabolic phenotyping approach to investigate Ov infection-induced metabolic disturbances at both the acute (1 month postinfection, 1 mpi) and chronic (4 mpi) stages in hamsters. A total of 22, 3, and 4 metabolites were found to be significantly different in the liver, serum, and urine, respectively, between Ov+ and Ov- groups. Elevated levels of hepatic amino acids and tricarboxylic acid (TCA)-cycle intermediates (fumarate and malate) were co-observed with liver injury in acute infection, whereas fibrosis-associated metabolites (e.g., glycine and glutamate) increased at the chronic infection stage. Lower levels of lipid signals ((CH₂)_n and CH₂CH₂CO) and higher levels of lysine and scyllo-inositol were observed in serum from Ov+ hamsters at 1 mpi compared to Ov- controls. Urinary levels of phenylacetylglycine (a host-bacterial cometabolite) and tauro-β-muricholic acid were higher in the Ov+ group, which coexisted with hepatic and mild kidney fibrosis. Furthermore, Ov+ animals showed higher relative abundances of fecal Methanobrevibacter (Archaea), Akkermansia, and Burkholderia-Paraburkholderia compared to the noninfected controls. In conclusion, along with liver and kidney pathologies, O. viverrini infection resulted in hepatic and mild renal pathologies, disturbed hepatic amino acid metabolism and the TCA cycle, and induced changes in the fecal microbial composition and urinary host-microbial cometabolism. This study provides the initial step toward an understanding of local and systemic metabolic responses of the host to O. viverrini infection.

Membrane Carriers and Transporters in Kidney Physiology and Disease

The growing information suggests that chronic kidney disease may affect expression and function of membrane carriers and transporters in the kidney. The dysfunction of carriers and transporters entails deficient elimination of uremic solutes as well as xenobiotics (drugs and toxins) with subsequent clinical consequences. The renal carriers and transporters are also targets of drugs used in clinical practice, and intentional drug-drug interactions in the kidney are produced to increase therapeutic efficacy. The understanding of membrane carriers and transporters function in chronic kidney disease is important not only to better characterize drug pharmacokinetics, drug actions in the kidney, or drug-drug interactions but also to define the organ pathophysiology.

Urinary Soluble CD163 and Disease Activity in Biopsy-Proven ANCA-Associated Glomerulonephritis

BACKGROUND AND OBJECTIVES

ANCA-associated GN is a common cause of rapidly progressive GN, with high relapse rates. The early recognition of an ANCA-associated GN relapse is of importance to prevent loss of kidney function. Urinary soluble CD163 has been identified as a promising marker of active ANCA-associated GN. Previous studies, however, are limited by the lack of histologic data.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We analyzed urinary soluble CD163 in 95 patients with ANCA-associated vasculitis who underwent a kidney biopsy. In total, 125 kidney tissue sections (first kidney biopsy, n=67; repeated biopsy, n=58) with concurrent 24-hour urine samples were studied. Correlation analyses comparing urinary soluble CD163 levels and morphologic features of ANCA-associated GN were performed using Spearman rank correlation analysis. The diagnostic performance of biomarkers to detect relapsing ANCA-associated GN was evaluated using receiver operating characteristics curve analysis.

RESULTS

High levels of urinary soluble CD163 were found in 96 (87%) of 110 biopsies with active ANCA-associated GN compared with one (7%) of 15 biopsies without active ANCA-associated GN and one (6%) of 17 healthy controls. Urinary soluble CD163 correlated with fibrinoid necrosis (Rho=0.48, P<0.001) and cellular crescents (Rho=0.70, P<0.001) on kidney biopsy. In repeated biopsies, urinary soluble CD163's sensitivity of 0.94 and specificity of 0.91 for the recognition of relapsing ANCA-associated GN appeared better than routine clinical measures. The presence of CD163⁺ cells in affected glomeruli confirmed urinary soluble CD163's origin.

CONCLUSIONS

Urinary soluble CD163 is associated with active ANCA-associated GN and correlates with histologic features as seen in ANCA-associated GN.

PODCAST

This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2020_11_17_CJN07210520_final.mp3.

COVID-19-Associated Kidney Injury: A Case Series of Kidney Biopsy Findings

BACKGROUND

Reports show that AKI is a common complication of severe coronavirus disease 2019 (COVID-19) in hospitalized patients. Studies have also observed proteinuria and microscopic hematuria in such patients. Although a recent autopsy series of patients who died with severe COVID-19 in China found acute tubular necrosis in the kidney, a few patient reports have also described collapsing glomerulopathy in COVID-19.

METHODS

We evaluated biopsied kidney samples from ten patients at our institution who had COVID-19 and clinical features of AKI, including proteinuria with or without hematuria. We documented clinical features, pathologic findings, and outcomes.

RESULTS

Our analysis included ten patients who underwent kidney biopsy (mean age: 65 years); five patients were black, three were Hispanic, and two were white. All patients had proteinuria. Eight patients had severe AKI, necessitating RRT. All biopsy samples showed varying degrees of acute tubular necrosis, and one patient had associated widespread myoglobin casts. In addition, two patients had findings of thrombotic microangiopathy, one had pauci-immune crescentic GN, and another had global as well as segmental glomerulosclerosis with features of healed collapsing glomerulopathy. Interestingly, although the patients had confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection by RT-PCR, immunohistochemical staining of kidney biopsy samples for SARS-CoV-2 was negative in all ten patients. Also, ultrastructural examination by electron microscopy showed no evidence of viral particles in the biopsy samples.

CONCLUSIONS

The most common finding in our kidney biopsy samples from ten hospitalized patients with AKI and COVID-19 was acute tubular necrosis. There was no evidence of SARS-CoV-2 in the biopsied kidney tissue.

Heterotrimeric Gα12/13 proteins in kidney injury and disease

Gα₁₂ and Gα₁₃ are ubiquitous members of the heterotrimeric guanine nucleotide-binding protein (G protein) family that play central and integrative roles in the regulation of signal transduction cascades within various cell types in the kidney. Gα₁₂/Gα₁₃ proteins enable the kidney to adapt to an ever-changing environment by transducing stimuli from cell surface receptors and accessory proteins to effector systems. Therefore, perturbations in Gα₁₂/Gα₁₃ levels or their activity can contribute to the pathogenesis of various renal diseases, including renal cancer. This review will highlight and discuss the complex and expanding roles of Gα₁₂/Gα₁₃ proteins on distinct renal pathologies, with emphasis on more recently reported findings. Deciphering how the different Gα₁₂/Gα₁₃ interaction networks participate in the onset and development of renal diseases may lead to the discovery of new therapeutic strategies.

Screening of Early Diagnostic Markers of Gentamicin-induced Acute Kidney Injury in Canines

Introduction

The value of neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (Kim-1), and liver-type fatty acid binding protein (L-FABP) was assessed in early diagnosis of gentamicin-induced acute kidney injury (AKI) in dogs.

Material and Methods

Subcutaneous gentamicin injection in 16 healthy adult beagles made the AKI model. Blood was sampled every 6 h to detect NGAL, Kim-1, L-FABP, and serum creatinine (SCr) concentrations. Kidney tissue of two dogs was taken before the injection, as soon as SCr was elevated (78 μmol/L), and when it had risen to 1.5 times the baseline, and haematoxylin-eosin staining and transmission electron microscopy (TEM) were used to observe changes.

Results

NGAL, Kim-1, and SCr levels were significantly increased (P < 0.05) at 18, 30, and 78 h post injection, but L-FABP concentration was not associated with renal injury. At the earliest SCr elevation stage, findings were mild oedema, degeneration, and vacuolisation in renal tubular epithelial cells in pathology, and mild cytoplasmic and mitochondrial oedema in TEM. At this time point, NGAL and Kim-1 concentrations were significantly increased (P < 0.05), indicating that these two molecules biomark early kidney injury in dogs. Using receiver operating characteristic curve analysis, their warning levels were > 25.31 ng/mL and > 48.52 pg/mL.

Conclusion

Plasma NGAL and Kim-1 above warning levels are early indicators of gentamicin-induced AKI in dogs.

Cytomegalovirus infection in kidney allografts: a review of literature

Cytomegalovirus (CMV) is an important cause of renal transplantation complications. It can cause different syndromes or end-organ diseases that can lead to unfavourable clinical outcomes and kidney allograft dysfunction. Although well documented as a systemic disease on renal transplant patients, affecting non-renal tissue, as gastrointestinal and respiratory tract, few cases have been reported in English-language indexed journals involving renal allograft lesions secondary to CMV. As an important differential diagnosis and etiological agent to acute and chronic rejection, the possibility of CMV kidney direct infection needs prompt recognition for effective treatment. In this paper, we will review the current literature about CMV nephritis and discuss the findings from each case report.

Kidney Biopsy-Related Complications in Hospitalized Patients with Acute Kidney Disease

BACKGROUND AND OBJECTIVES

Patients are informed of the risk of kidney biopsy-related complications using data from nonhospitalized patients, which may underestimate the risk for hospitalized patients. We evaluated the rate and risk factors of kidney biopsy-related complications in hospitalized patients with acute kidney disease (AKD) to better estimate the risk in this population.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We used data from the Yale biopsy cohort to evaluate rates of kidney biopsy-related complications including adjudicated procedure-related bleeding requiring blood transfusions or angiographic interventions, medium- or large-sized hematomas, reimaging after biopsy including abdominal ultrasonography or computed tomography, and death in hospitalized patients with AKD (including AKI). We evaluated univariable and multivariable association of risk factors with transfusions. We compared rates of complications between hospitalized and nonhospitalized patients.

RESULTS

Between 2015 and 2017, 159 hospitalized patients underwent a kidney biopsy for AKD evaluation, of which 80 (51%) had stage 1 AKI, 42 (27%) had stage 2 (or higher) AKI, and 27 (17%) had AKD (without AKI). Of these, 12 (8%; 95% confidence interval [95% CI], 5% to 15%) required a transfusion, three (2%; 95% CI, 1% to 5%) required an intervention, 11 (7%; 95% CI, 4% to 12%) had hematoma, and 31 (20%; 95% CI, 14% to 26%) required reimaging after biopsy. Of the four (3%; 95% CI, 1% to 6%) deaths during hospitalization, none were related to the biopsy. Female sex, lower platelet count, and higher BUN were associated with postbiopsy transfusions on univariable and multivariable analyses. Trainee as proceduralist and larger needle gauge were associated with transfusions in univariable, but not multivariable, analysis. Nonhospitalized patients had lower rates of transfusion than hospitalized patients, although the latter also had lower prebiopsy hemoglobin and greater surveillance after biopsy.

CONCLUSIONS

Hospitalized patients experience higher risk of postbiopsy complications than previously reported and several factors, such as lower platelet count, female sex, and higher BUN, are associated with this risk.

Schistosomiasis and hydration status: Schistosoma haematobium, but not Schistosoma mansoni increases urine specific gravity among rural Tanzanian women

OBJECTIVES

Schistosome infections can damage organs important for water homeostasis, especially the kidneys. Urogenital schistosomiasis (caused by Schistosoma haematobium) increases protein and blood in urine and intestinal schistosomiasis (caused by S. mansoni) affects total body water. However, no data exist on how different schistosome species affect urine specific gravity (USG), a hydration biomarker. Therefore, we assessed the relationship between S. haematobium- and S. mansoni-infected and uninfected women and USG in rural Tanzania.

MATERIALS AND METHODS

Surveys were conducted and stool and urine samples were collected among 211 nonpregnant women aged 18-50. S. haematobium eggs were detected using the urine filtration method. S. mansoni eggs were detected using the Kato Katz method. USG was measured using a refractometer and analyzed as both a continuous and dichotomous variable. Regression (linear/logistic) models were estimated to test the relationship between infection and hydration status.

RESULTS

The prevalence of S. haematobium was 5.9% and S. mansoni was 5.4% with no coinfections. In regression models, S. haematobium-infected women had significantly higher USG (Beta = 0.007 g mL^-1 ; standard error = 0.002; p = 0.001) and odds (Odds ratio: 7.76, 95% CI: 1.21-49.5) of elevated USG (>1.020 g mL^-1 ) than uninfected women, whereas S. mansoni-infected women did not.

DISCUSSION

Schistosoma haematobium, but not S. mansoni, infection is associated with higher USG and risk of inadequate hydration. Future work should determine whether findings are attributable to parasite-induced debris in urine or urinary tract pathologies and signs of renal damage. Human and non-human primate studies using USG in schistosome-endemic areas should account for schistosomiasis.

Therapeutic Role of Tangshenkang Granule () in Rat Model with Diabetic Nephropathy

OBJECTIVE

To evaluate the renal protective effect of Tangshenkang Granule () in a rat model of diabetic nephropathy (DN).

METHODS

Forty male Sprague-Dawley rats were randomly divided into control, DN, Tangshenkang and benazepril groups. DN model was established in the rats of DN, Tangshenkang and benazepril groups. Tangshenkang Granule solution and benazepril hydrochloride solution were intragastrically administered daily to the rats in the Tangshenkang and benazepril groups for 8 weeks, respectively. Urinary albumin and creatinine were detected. The albumin/creatinine (ACR) was calculated in addition to 24 h urinary protein (24-h UPr), serum creatinine (Scr), blood urea nitrogen (BUN), total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL), high-density lipoprotein (HDL), and creatinine clearance rate (Ccr). Right kidneys were harvested for pathological observation using periodic acid-silver methenamine-Masson staining. The average glomerular diameter (DG), average glomerular (AG) and mesangial areas (AM) were measured. The thickness of glomerular basement membrane (TGBM) was detected using transmission electron microscope.

RESULTS

Compared with rats in the control group, rats in the DN group showed significantly decreased body weight, increased hypertrophy index, 24-h urinary volume, 24-h UPr, ACR, Scr, BUN, Ccr, blood lipids as well as renal pathological indices including DG, AG, AM, AM/AG and TGBM (P <0.05). Compared with the DN group, the weights of rats in the Tangshenkang and benazepril groups were significantly increased, and the renal hypertrophy indices were significantly decreased (P <0.05). The 24-h urinary volumes, ACR, 24-h UPr, Scr, BUN, Ccr, LDL, DG, AG, AM and TGBM were obviously decreased (P <0.05). Compared with the benazepril group, the Tangshenkang group showed significantly decreased levels of ACR, 24-h UPr, AG and AM (P <0.05).

CONCLUSIONS

Tangshenkang Granule decreased the urinary protein, attenuated the high glomerular filtration rate and improved lipid metabolism in DN rats, and prevented further injury induced by diabetic nephropathy.

The Renal Connexome and Possible Roles of Connexins in Kidney Diseases

Connexins are membrane-spanning proteins that allow for the formation of cell-to-cell channels and cell-to-extracellular space hemichannels. Many connexin subtypes are expressed in kidney cells. Some mutations in connexin genes have been linked to various human pathologies, including cardiovascular, neurodegenerative, lung, and skin diseases, but the exact role of connexins in kidney disease remains unclear. Some hypotheses about a connection between genetic mutations, endoplasmic reticulum (ER) stress, and the unfolded protein response (UPR) in kidney pathology have been explored. The potential relationship of kidney disease to abnormal production of connexin proteins, mutations in their genes together with ER stress, or the UPR is still a matter of debate. In this scenario, it is tantalizing to speculate about a possible role of connexins in the setting of kidney pathologies that are thought to be caused by a deregulated podocyte protein expression, the so-called podocytopathies. In this article, we give examples of the roles of connexins in kidney (patho)physiology and propose avenues for further research concerning connexins, ER stress, and UPR in podocytopathies that may ultimately help refine drug treatment.

Insights into the renal pathogenesis in Schimke immuno-osseous dysplasia: A renal histological characterization and expression analysis

Schimke immuno-osseous dysplasia (SIOD) is a pleiotropic disorder caused by mutations in the SWI/SNF2-related, matrix-associated, actin-dependent regulator of chromatin, subfamily a-like-1 (SMARCAL1) gene, with multiple clinical features, notably end-stage renal disease. Here we characterize the renal pathology in SIOD patients. Our analysis of SIOD patient renal biopsies demonstrates the tip and collapsing variants of focal segmental glomerulosclerosis (FSGS). Additionally, electron microscopy revealed numerous glomerular abnormalities most notably in the podocyte and Bowman's capsule. To better understand the role of SMARCAL1 in the pathogenesis of FSGS, we defined SMARCAL1 expression in the developing and mature kidney. In the developing fetal kidney, SMARCAL1 is expressed in the ureteric epithelium, stroma, metanephric mesenchyme, and in all stages of the developing nephron, including the maturing glomerulus. In postnatal kidneys, SMARCAL1 expression is localized to epithelial tubules of the nephron, collecting ducts, and glomerulus (podocytes and endothelial cells). Interestingly, not all cells within the same lineage expressed SMARCAL1. In renal biopsies from SIOD patients, TUNEL analysis detected marked increases in DNA fragmentation. Our results highlight the cells that may contribute to the renal pathogenesis in SIOD. Further, we suggest that disruptions in genomic integrity during fetal kidney development contribute to the pathogenesis of FSGS in SIOD patients.

Thrombotic microangiopathy and acute kidney injury associated with intravenous abuse of an oral extended-release formulation of oxymorphone hydrochloride: kidney biopsy findings and report of 3 cases

There have been recent reports and warnings of a thrombotic thrombocytopenic purpura-like illness associated with intravenous abuse of a prescription narcotic intended for oral use. Oral extended-release oxymorphone hydrochloride (Opana ER) is an opioid agonist that has undergone a tamper-resistant reformulation. However, instances of melting and dissolving tablets with subsequent injection continue to occur. We report 3 cases of hemolytic anemia and acute kidney injury associated with intravenous abuse of this reformulated drug. All 3 patients underwent native kidney biopsy that showed thrombotic microangiopathy characterized by severe arterial and arteriolar mucoid intimal edema with resultant glomerular and tubular ischemia. All 3 patients required hemodialysis and 2 also underwent therapeutic plasma exchange. Early follow-up suggests that kidney outcome is poor, with only partial recovery of function despite aggressive treatment. The specific component or components of this reformulated drug associated with endothelial injury is unknown. Most importantly, a high degree of clinical suspicion is needed when treating patients with a thrombotic thrombocytopenic purpura-like illness of unknown cause.