Hyperspectral imaging to predict the effect of cyclophosphamide in primary membranous nephropathy.

BACKGROUND: Presently, there is a lack of accurate predictors of the efficacy of primary membranous nephropathy. The aim of this study is to explore the application value of hyperspectral imaging in predicting the efficacy of cyclophosphamide treatment in primary membranous nephropathy. METHOD: A total of 30 patients with primary membranous nephropathy who were treated with glucocorticoid combined with cyclophosphamide were collected. Hematoxylin-eosin stained renal pathological images were acquired by hyperspectral imaging system at the spectral range of 400-1000 nm. The remission group data set contained 23 samples, while the non-remission group data set contained 28 samples. A one-dimensional convolutional neural network model was established to train and test the hyperspectral data, and the performance of the model was evaluated. RESULT: From the spectral curve, the spectral difference between the remission group and the non-remission group was obvious between 525 and 700 nm. The spectral data in this band were analyzed by one-dimensional convolutional neural network, and the confusion matrix showed that the remission group and the non-remission group were successfully classified. The precision and recall were 0.89 and 0.81 for the non-response group and 0.83 and 0.90 for the response group, respectively, with an F1 score of 0.85 in both groups. The area under the AUC curve of the classification model reached 0.857. CONCLUSION: In this study, a one-dimensional convolutional neural network model was used to analyze the hyperspectral images of renal pathology of PMN patients, and the patients in remission group and non-remission group were successfully classified after glucocorticoid combined with cyclophosphamide treatment.

Preliminary study on the application of renal ultrasonography radiomics in the classification of glomerulopathy.

BACKGROUND: The aim of this study was to investigate the potential use of renal ultrasonography radiomics features in the histologic classification of glomerulopathy. METHODS: A total of 623 renal ultrasound images from 46 membranous nephropathy (MN) and 22 IgA nephropathy patients were collected. The cases and images were divided into a training group (51 cases with 470 images) and a test group (17 cases with 153 images). A total of 180 dimensional features were designed and extracted from the renal parenchyma in the ultrasound images. Least absolute shrinkage and selection operator (LASSO) logistic regression was then applied to these normalized radiomics features to select the features with the highest correlations. Four machine learning classifiers, including logistic regression, a support vector machine (SVM), a random forest, and a K-nearest neighbour classifier, were deployed for the classification of MN and IgA nephropathy. Subsequently, the results were assessed according to accuracy and receiver operating characteristic (ROC) curves. RESULTS: Patients with MN were older than patients with IgA nephropathy. MN primarily manifested in patients as nephrotic syndrome, whereas IgA nephropathy presented mainly as nephritic syndrome. Analysis of the classification performance of the four classifiers for IgA nephropathy and MN revealed that the random forest achieved the highest area under the ROC curve (AUC) (0.7639) and the highest specificity (0.8750). However, logistic regression attained the highest accuracy (0.7647) and the highest sensitivity (0.8889). CONCLUSIONS: Quantitative radiomics imaging features extracted from digital renal ultrasound are fully capable of distinguishing IgA nephropathy from MN. Radiomics analysis, a non-invasive method, is helpful for histological classification of glomerulopathy.

Application of direct stochastic optical reconstruction microscopy (dSTORM) to the histological analysis of human glomerular disease.

Electron microscopy (EM) following immunofluorescence (IF) imaging is a vital tool for the diagnosis of human glomerular diseases, but the implementation of EM is limited to specialised institutions and it is not available in many countries. Recent progress in fluorescence microscopy now enables conventional widefield fluorescence microscopes to be adapted at modest cost to provide resolution below 50 nm in biological specimens. We show that stochastically switched single-molecule localisation microscopy can be applied to clinical histological sections stained with standard IF techniques and that such super-resolved IF may provide an alternative means to resolve ultrastructure to aid the diagnosis of kidney disease where EM is not available. We have implemented the direct stochastic optical reconstruction microscopy technique with human kidney biopsy frozen sections stained with clinically approved immunofluorescent probes for the basal laminae and immunoglobulin G deposits. Using cases of membranous glomerulonephritis, thin basement membrane lesion, and lupus nephritis, we compare this approach to clinical EM images and demonstrate enhanced imaging compared to conventional IF microscopy. With minor modifications in established IF protocols of clinical frozen renal biopsies, we believe the cost-effective adaptation of conventional widefield microscopes can be widely implemented to provide super-resolved image information to aid diagnosis of human glomerular disease.

Spatial-Spectral Density Peaks-Based Discriminant Analysis for Membranous Nephropathy Classification Using Microscopic Hyperspectral Images.

The traditional differential diagnosis of membranous nephropathy (MN) mainly relies on clinical symptoms, serological examination and optical renal biopsy. However, there is a probability of false positives in the optical inspection results, and it is unable to detect the change of biochemical components, which poses an obstacle to pathogenic mechanism analysis. Microscopic hyperspectral imaging can reveal detailed component information of immune complexes, but the high dimensionality of microscopic hyperspectral image brings difficulties and challenges to image processing and disease diagnosis. In this paper, a novel classification framework, including spatial-spectral density peaks-based discriminant analysis (SSDP), is proposed for intelligent diagnosis of MN using a microscopic hyperspectral pathological dataset. SSDP constructs a set of graphs describing intrinsic structure of MHSI in both spatial and spectral domains by employing density peak clustering. In the process of graph embedding, low-dimensional features with important diagnostic information in the immune complex are obtained by compacting the spatial-spectral local intra-class pixels while separating the spectral inter-class pixels. For the MN recognition task, a support vector machine (SVM) is used to classify pixels in the low-dimensional space. Experimental validation data employ two types of MN that are difficult to distinguish with optical microscope, including primary MN and hepatitis B virus-associated MN. Experimental results show that the proposed SSDP achieves a sensitivity of 99.36%, which has potential clinical value for automatic diagnosis of MN.

Potential value of three-dimensional ultrasonography in diagnosis of diabetic nephropathy in Chinese diabetic population with kidney injury.

BACKGROUND: To explore the potential value of three-dimensional ultrasonography (3DUS) and contrast-enhanced ultrasound (CEUS) in the diagnosis of diabetic nephropathy (DN) in Chinese diabetic patients with kidney injury. METHODS: Patients with type 2 diabetes mellitus and kidney injury in our hospital were enrolled, and the clinical characteristics as well as the laboratory data of patients were collected; 3DUS and CEUS were used to evaluate the morphological structure and blood perfusion of kidneys. Eligible patients were categorized into two groups based on renal biopsy results: DN group and non-diabetic renal diseases (NDRD) group. Correlation analysis and logistic regression analysis were applied to identify the risk factors of DN development. RESULTS: A total of 115 patients aged from 24 to 78 years old were recruited in the experiment, of which 64 patients (55.65%) and 51 patients (44.35%) were in the DN group and NDRD group, respectively. After correction to CKD stage, BMI and right kidney volume index were retained to identify patients with DN. The ROC of the logistic regression model had an AUC of 0.703 (95% CI: 0.591-0.815) and it was higher than both indicators. CONCLUSION: 3DUS has potential value in the diagnosis of diabetic nephropathy in Chinese diabetic population with kidney injury and may act as an auxiliary diagnosis for DN. More prospective and well-designed studies with larger samples are needed to verify the result.

A case of IgG4-related tubulointerstitial nephritis and membranous glomerulonephritis during the clinical course of gastric cancer: Imaging features of IgG4-related kidney disease.

We describe an 81-year-old man with immunoglobulin G4-related disease (IgG4-RD) presenting with submandibular gland, lymph node, lung, kidney, aortic wall, and prostate lesions with concomitant gastric cancer. After curative surgical treatment of the gastric cancer, corticosteroid therapy for progressively decreasing renal function was started. Before starting steroid therapy, fluorodeoxyglucose positron emission tomography-computed tomography revealed multiple lesions of IgG4-RD but no metastasis of the cancer. However, the patient died 3 months after initiation of corticosteroid therapy because of recurrence of the gastric cancer. In this case, the imaging features of IgG4-tubulointerstitial nephritis dramatically changed during the clinical course of co-existing gastric cancer. The imaging features of the present case may provide clues to the pattern of spread of IgG4 lesions in the kidney.

High Spatial Resolution MALDI-MS Imaging in the Study of Membranous Nephropathy.

PURPOSE: Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) technology has advanced rapidly during recent years with the development of instruments equipped with low-diameter lasers that are suitable for high spatial resolution imaging. This may provide significant advantages in certain fields of molecular pathology where more specific protein fingerprints of individual cell types are required, such as renal pathology. EXPERIMENTAL DESIGN: Here MALDI-MSI analysis of a cohort of membranous nephropathy (MN) patients is performed among which patients either responded favorably (R; n = 6), or unfavorably (NR; n = 4), to immunosuppressive treatment (Ponticelli Regimen), employing a 10 µm laser spot diameter. RESULTS: Specific tryptic peptide profiles of the different cellular regions within the glomerulus can be generated, similarly for the epithelial cells belonging to the proximal and distal tubules. Conversely, specific glomerular and sub-glomerular profiles cannot be obtained while using the pixel size performed in previous studies (50 µm). Furthermore, two proteins are highlighted, sonic hedgehog and α-smooth muscle actin, whose signal intensity and spatial localization within the sub-glomerular and tubulointerstitial compartments differ between treatment responders and non-responders. CONCLUSIONS AND CLINICAL RELEVANCE: The present study exemplifies the advantage of using high spatial resolution MALDI-MSI for the study of MN and highlights that such findings have the potential to provide complementary support in the routine prognostic assessment of MN patients.

COL4A5 and LAMA5 variants co-inherited in familial hematuria: digenic inheritance or genetic modifier effect?

BACKGROUND: About 40-50% of patients with familial microscopic hematuria (FMH) caused by thin basement membrane nephropathy (TBMN) inherit heterozygous mutations in collagen IV genes (COL4A3, COL4A4). On long follow-up, the full phenotypic spectrum of these patients varies a lot, ranging from isolated MH or MH plus low-grade proteinuria to chronic renal failure of variable degree, including end-stage renal disease (ESRD). METHODS: Here, we performed Whole Exome Sequencing (WES) in patients of six families, presenting with autosomal dominant FMH, with or without progression to proteinuria and loss of renal function, all previously found negative for severe collagen IV mutations. Hierarchical filtering of the WES data was performed, followed by mutation prediction analysis, Sanger sequencing and genetic segregation analysis. RESULTS: In one family with four patients, we found evidence for the contribution of two co-inherited variants in two crucial genes expressed in the glomerular basement membrane (GBM); LAMA5-p.Pro1243Leu and COL4A5-p.Asp654Tyr. Mutations in COL4A5 cause classical X-linked Alport Syndrome, while rare mutations in the LAMA5 have been reported in patients with focal segmental glomerulosclerosis. The phenotypic spectrum of the patients includes hematuria, proteinuria, focal segmental glomerulosclerosis, loss of kidney function and renal cortical cysts. CONCLUSIONS: A modifier role of LAMA5 on the background of a hypomorphic Alport syndrome causing mutation is a possible explanation of our findings. Digenic inheritance is another scenario, following the concept that mutations at both loci more accurately explain the spectrum of symptoms, but further investigation is needed under this concept. This is the third report linking a LAMA5 variant with human renal disease and expanding the spectrum of genes involved in glomerular pathologies accompanied by familial hematurias. The cystic phenotype overlaps with that of a mouse model, which carried a Lama5 hypomorphic mutation that caused severely reduced Lama5 protein levels and produced kidney cysts.

A Case of the nephrotic syndrome in bone marrow transplantation recipient, histologically showing overlapped glomerular lesions of thrombotic microangiopathy and membranous nephropathy.

Nephrotic syndrome (NS) rarely occurs in post-hematopoietic stem cell transplantation (HSCT) recipients but represents the renal manifestation of graft-versus-host disease (GVHD). Membranous nephropathy (MN) accounts for almost two thirds of post-HSCT NS and is caused by immune complex deposition. Renal thrombotic microangiopathy (TMA) without fulfillment of clinical criteria for TMA has been underreported because of reduced opportunity for histological examination. However, renal TMA has recently been reported in association with GVHD and humoral immunological reactions. Although both MN and TMA after HSCT are associated with GVHD and immunological abnormalities, these diseases are exceptionally coexistent in renal biopsy specimens. We herein describe a case of post-HSCT NS, histologically showing overlapped lesions of TMA and MN. Renal biopsy specimen after presentation of NS revealed early stage MN and TMA with evidence of chronicity. TMA was thought to have preceded MN, and renal biopsy at the phase of pre-nephrotic proteinuria might reveal earlier histological changes of isolated renal TMA. Detection of subclinical renal TMA earlier by spontaneous renal biopsy can help prevent progression of renal injury or overlapping of other renal pathologies. We also demonstrated Th2 predominant intraglomerular infiltration of lymphocytes by immunohistochemistry.

The Application of Digital Pathology to Improve Accuracy in Glomerular Enumeration in Renal Biopsies.

BACKGROUND: In renal biopsy reporting, quantitative measurements, such as glomerular number and percentage of globally sclerotic glomeruli, is central to diagnostic accuracy and prognosis. The aim of this study is to determine the number of glomeruli and percent globally sclerotic in renal biopsies by means of registration of serial tissue sections and manual enumeration, compared to the numbers in pathology reports from routine light microscopic assessment. DESIGN: We reviewed 277 biopsies from the Nephrotic Syndrome Study Network (NEPTUNE) digital pathology repository, enumerating 9,379 glomeruli by means of whole slide imaging. Glomerular number and the percentage of globally sclerotic glomeruli are values routinely recorded in the official renal biopsy pathology report from the 25 participating centers. Two general trends in reporting were noted: total number per biopsy or average number per level/section. Both of these approaches were assessed for their accuracy in comparison to the analogous numbers of annotated glomeruli on WSI. RESULTS: The number of glomeruli annotated was consistently higher than those reported (p<0.001); this difference was proportional to the number of glomeruli. In contrast, percent globally sclerotic were similar when calculated on total glomeruli, but greater in FSGS when calculated on average number of glomeruli (p<0.01). The difference in percent globally sclerotic between annotated and those recorded in pathology reports was significant when global sclerosis is greater than 40%. CONCLUSIONS: Although glass slides were not available for direct comparison to whole slide image annotation, this study indicates that routine manual light microscopy assessment of number of glomeruli is inaccurate, and the magnitude of this error is proportional to the total number of glomeruli.

Quantitative analysis of four types of primary glomeropathy by application of a decision forest to ultrasonic and laboratory characteristics.

The aim of this study was to apply a decision forest to analysis of the ultrasound characteristics and laboratory test indices of four types of primary glomerulopathy, and quantitative analysis of the four pathologic types using a combination of these two methods. The decision trees were derived from 41 clinical indices and 5 characteristic sonographic indices obtained for the left kidney. Fifty-six patients who had undergone ultrasound-guided renal biopsy were reviewed retrospectively, and on pathologic examination, the patients were diagnosed with primary glomerulopathy, which includes mesangial proliferative glomerulonephritis, membranous nephropathy, immunoglobulin A nephropathy and minimal change disease. In this study, eight characteristic indicators were correlated with pathologic type in the 56 cases of primary glomerulopathy. The order calculated by decision forests, from high to low, is proteinuria, length of kidney, serum creatinine, plasma albumin, area of kidney, total protein, thickness of renal parenchyma, 24-h urine protein. The glomerulopathy with the highest ++++ proteinuria is membranous nephropathy, which accounts for 39.2% (22/56) of the total sample; this was followed by minimal change disease, mesangial proliferative glomerulonephritis and immunoglobulin A nephropathy. On the basis of our analysis of 41 clinical indices, the key indices for quantitative analysis of primary glomerulonephritis are laboratory tests, and these include urine protein, serum creatinine, plasma albumin, total serum protein and 24-h urine protein. The three key sonographic features are measurement indices: renal length, renal area and renal parenchymal thickness. From the eight characteristic indicators, we observed that with respect to severity (from most severe to least severe), the four types of glomerulopathy are membranous nephropathy, minimal change disease, mesangial proliferative glomerulonephritis and immunoglobulin A nephropathy.

Incidental renal artery pseudoaneurysm after percutaneous native renal biopsy.

Renal artery pseudoaneurysm (RAP) is an uncommon but potentially life-threatening condition that is often difficult to diagnose. Rarely, it can occur as a complication associated with a percutaneous renal biopsy procedure. The clinical manifestations vary from asymptomatic lesions found incidentally on imaging studies to a mass causing high blood pressure, pain, haematuria and rupture. Although the risk of rupture is considered low, RAP is associated with a high death rate if ruptured. Currently, with the aid of high-quality interventional radiology, this challenging pathology can be effectively treated. In this report, we describe a case of RAP that was incidentally discovered 4 years after percutaneous renal biopsy which was successfully treated with selective angiographic embolisation.

Thromboembolic complications in membranous nephropathy patients with nephrotic syndrome-a prospective study.

BACKGROUND: Venous thromboembolism (VTE) is one of the most serious complications in membranous nephropathy (MN). We investigate the incidence of VTE in MN patients with nephrotic syndrome (NS). METHODS: A total of 100 MN patients with NS were enrolled into this prospective study. The diagnosis of VTE was based on contrast-enhanced dual source computed tomography angiography. RESULTS: Venous thromboembolism was demonstrated in 36 patients (36%). 33 patients (33%) had renal vein thrombosis (RVT), 17 patients (17%) had pulmonary embolism (PE). Flank pain was noted in 5 patients and gross hematuria in 2 patients with RVT. Dyspnea and chest pain were present in 9 patients with PE. The positive predictive value for D-dimer level was 69.4%, negative predictive value for D-dimer level was 96.1% in patients with MN. Of all the risk factors presented, D-dimer level, proteinuria, the ratio of proteinuria to serum albumin were independent risk factors for the development of VTE (P<0.05), but the plasma level of antithrombin Ш was not correlated with VTE in this study. In follow up, venous thrombosis disappeared after anticoagulant treatment with low-molecular-weight heparins in 28 patients. CONCLUSION: Venous thromboembolism was confirmed in 36% of MN patients with NS. Renal vein thrombosis and pulmonary embolism are common and usually asymptomatic. Computed tomography angiography can be used effectively to examine suspected patients. Measurement of D-dimer is helpful in VTE diagnosis. It is important that clinicians are aware that VTE should be considered as a common complication in MN patients with NS.

A fulminant case of renal vein thrombosis in a patient with autoimmune disorder and membranous nephropathy.

A previously healthy middle-aged woman noted a rapid onset of flank pain with gross hematuria. Enhanced CT scan showed thrombosis of the inferior vena cava and right renal vein. Laboratory findings revealed nephrotic proteinuria, Sjogren's syndrome (SjS), and Graves' disease (GD). A right nephrectomy was performed because of progressive and refractory renal necrosis. Renal specimens showed venous infarction with diffuse hemorrhagic and severe congestive renal necrosis, and membranous nephropathy (MN). The present case was diagnosed as acute renal necrosis due to catastrophic thrombosis in a patient with SjS, GD, and MN. It was thought that sudden development of thrombosis may have been caused by the status of the autoimmune disorders, and the associated MN.

Bilateral renal vein thrombosis secondary to membraneous glomerulonephritis: successful treatment with thrombolytic therapy.

Renal vein thrombosis (RVT) is a rare phenomenon. Bilateral RVT is even less common. RVT has been reported as idiopathic or in association with puerperium, hypercoagulable states, membraneous glomerulonephritis (MGn), renal transplantation, malignancy, and renal vein instrumentation or trauma. Due to its rarity, the literature describing RVT consists mainly of isolated case reports and there are no consistent recommendations regarding diagnosis and treatment of this vascular emergency. We present a case of bilateral RVT associated with MGn. A 45-year-old man complaining of nonspecific abdominal pain of 2 days' duration was found to have bilateral RVT upon computed tomographic evaluation. He was successfully treated with emergent endovascular mechanical thrombectomy in conjunction with chemical thrombolysis and subsequently therapeutically anticoagulated. A renal biopsy demonstrated MGn, and the patient was placed on an appropriate medical regimen. He is well approximately 18 months later, with preserved renal function. Despite a multitude of potential causative mechanisms, all RVT patients should undergo a thorough workup for underlying hypercoagulable disorder and underlying benign or malignant renal causes. Treatment is aimed at prompt relief of venous obstruction and preservation of renal parenchymal function. Interventional radiological procedures, including thrombolysis and thrombectomy, have proven to be valuable in the treatment of RVT. Surgical options include thrombectomy and nephrectomy.

A unique presentation of antiphospholipid antibody syndrome in pregnancy.

Primary antiphospholipid antibody syndrome (APS) is a protean disease with many manifestations including venous and arterial thrombosis, recurrent foetal loss, preeclampsia, intrauterine growth retardation, cardiac valvular disease, glomerulonephritis, thrombocytopaenia and livedo reticularis. We report an interesting case of a 19-year-old woman where the diagnosis of primary APS was initially made in the peripartum period.

Chronic inflammatory demyelinating polyneuropathy associated with membranous glomerulonephritis: case report.

A case of Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) with Membranous Glomerulonephritis (MGN) is reported. This is the second case recorded in the literature and the article compares this case with the other reported case, including immunological implications.