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Copyright of Journal of Ankara University Faculty of Medicine / Ankara Üniversitesi Tip Fakültesi Mecmuasi is the property of Galenos Yayinevi Tic. LTD. STI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Namık Kemal Tıp Dergisi is the property of Galenos Yayinevi Tic. LTD. STI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

IgA nephropathy progresses to kidney failure, making early detection important. However, definitive diagnosis depends on invasive kidney biopsy. This study aimed to develop non-invasive prediction models for IgA nephropathy using machine learning. We collected retrospective data on demographic characteristics, blood tests, and urine tests of the patients who underwent kidney biopsy. The dataset was divided into derivation and validation cohorts, with temporal validation. We employed five machine learning models—eXtreme Gradient Boosting (XGBoost), LightGBM, Random Forest, Artificial Neural Networks, and 1 Dimentional-Convolutional Neural Network (1D-CNN)—and logistic regression, evaluating performance via the area under the receiver operating characteristic curve (AUROC) and explored variable importance through SHapley Additive exPlanations method. The study included 1268 participants, with 353 (28%) diagnosed with IgA nephropathy. In the derivation cohort, LightGBM achieved the highest AUROC of 0.913 (95% CI 0.906–0.919), significantly higher than logistic regression, Artificial Neural Network, and 1D-CNN, not significantly different from XGBoost and Random Forest. In the validation cohort, XGBoost demonstrated the highest AUROC of 0.894 (95% CI 0.850–0.935), maintaining its robust performance. Key predictors identified were age, serum albumin, IgA/C3, and urine red blood cells, aligning with existing clinical insights. Machine learning can be a valuable non-invasive tool for IgA nephropathy. [ABSTRACT FROM AUTHOR]

Alport syndrome is a genetic kidney disease that causes worsening of kidney function over time, often progressing to kidney failure. Some types of Alport syndrome cause other symptoms and signs, including hearing loss and eye abnormalities. Research now indicates that Alport syndrome (autosomal dominant inheritance) is the most common form. Alport syndrome can have X-linked or a rare form of autosomal recessive inheritance. Traditionally, a kidney biopsy was used to diagnose Alport syndrome, but genetic testing provides a more precise and less invasive means of diagnosis and reveals the underlying pattern of inheritance. At present, there are no specific curative treatments for Alport syndrome however there is a strong international effort in pursuit of future therapies. Currently, angiotensin-converting enzyme inhibitors (ACEi), or an angiotensin receptor blocker (ARB) if a patient cannot tolerate an ACEi, slow down the progression of kidney disease and can delay the onset of kidney failure by years. There are other potential treatments in research that potentially can help delay the onset of kidney issues. Early treatment of patients and identification of their at-risk relatives is a priority. People living with Alport syndrome and their doctors now benefit from an active international research community working on translating further treatments into clinical practice and providing up-to-date clinical guidelines. [ABSTRACT FROM AUTHOR]

Introduction: The causal relationship between hyperparathyroidism and kidney graft dysfunction remains inconclusive. Applying Bradford‐Hill's temporality and consistency causation principles, we assessed the effect of parathyroid hormone (iPTH) on graft histology and eGFR trajectory on kidney transplant recipients (KTRs) with normal time‐zero graft biopsies. Methods: Retrospective cohort study evaluating the effect of hyperparathyroidism on interstitial fibrosis and tubular atrophy (IF/TA) development in 1232 graft biopsies. Pre‐transplant hyperparathyroidism was categorized by KDIGO or KDOQI criteria, and post‐transplant hyperparathyroidism by iPTH >1× and >2× the URL 1 year after transplantation. Results: We included 325 KTRs (56% female, age 38 ± 13 years, follow‐up 4.2 years [IQR: 2.7‐5.8]). Based on pre‐transplant iPTH levels, 26% and 66% exceeded the KDIGO and KDOQI targets, respectively. There were no significant differences in the development of >25% IF/TA between KTRs with pre‐transplant iPTH levels above and within target range according to KDIGO (53% vs. 62%, P =.16, HR.94 [95% CI:.67–1.32]) and KDOQI (60% vs. 60%, P = 1.0, HR 1.19 [95% CI:.88–1.60]) criteria. Similarly, there were no differences when using 1 year post‐transplant iPTH cut‐offs > 88 pg/mL (58% vs. 64%, P =.33) and > 176 pg/mL (55% vs. 62%, P =.19). After adjusting for confounders, no significant differences were observed in eGFR trajectories among the iPTH strata. Conclusion: In young KTRs who received a healthy graft, no association was found between increased pre‐ and post‐transplant iPTH levels and graft dysfunction, as assessed histologically and through eGFR trajectory. The concept of hyperparathyroidism as a risk factor for graft dysfunction in recipients at low risk requires reevaluation. [ABSTRACT FROM AUTHOR]

Background: The most common complication of percutaneous kidney biopsy is bleeding, which can be seen in up to one-third of cases. The aim of this study was to evaluate the effect of prebiopsy administration of intranasal desmopressin acetate in reducing the incidence of biopsy-related bleeding complications. Materials and Methods: This was a prospective randomized double-blind pilot study conducted at our center from January 2021 to September 2022. Consecutive adult patients who underwent native percutaneous kidney biopsy with an estimated glomerular filtration rate (eGFR) ≤45 ml/min/1.73 m² were randomized into a placebo (saline intranasal spray) group versus intranasal desmopressin group. The bleeding complications were compared between the two groups. Results: A total of 80 patients who underwent kidney biopsy at our center from January 2021 to September 2022 with eGFR ≤45 ml/min/1.73 m² were included (40 patients in desmopressin group and 40 patients in non-desmopressin group) in the study. The mean age of the patients was 44 ± 12 years with a mean eGFR of 20.82 ± 12.64 ml/min/1.73 m². Intranasal desmopressin administration before kidney biopsy was associated with a significantly higher number of minor bleeding complications (P = 0.02) and no significant reduction in major complications (P = 0.15) when compared with a group that did not receive desmopressin. Other complications like hypotension, flushing, and vasovagal syncope were not statistically significantly associated with the use of desmopressin. Conclusion: Our study did not find any utility of prophylactic desmopressin use before kidney biopsy in patients with kidney dysfunction. [ABSTRACT FROM AUTHOR]

Background Early progression of chronic histologic lesions in kidney allografts represents the main finding in graft attrition. The objective of this retrospective cohort study was to elucidate whether HLA histocompatibility is associated with progression of chronic histologic lesions in the first year post-transplant. Established associations of de novo donor-specific antibody (dnDSA) formation with HLA mismatch and microvascular inflammation (MVI) were calculated to allow for comparability with other study cohorts. Methods We included 117 adult kidney transplant recipients, transplanted between 2016 and 2020 from predominantly deceased donors, who had surveillance biopsies at 3 and 12 months. Histologic lesion scores were assessed according to the Banff classification. HLA mismatch scores [i.e. eplet, predicted indirectly recognizable HLA-epitopes algorithm (PIRCHE-II), HLA epitope mismatch algorithm (HLA-EMMA), HLA whole antigen A/B/DR] were calculated for all transplant pairs. Formation of dnDSAs was quantified by single antigen beads. Results More than one-third of patients exhibited a progression of chronic lesion scores by at least one Banff grade in tubular atrophy (ct), interstitial fibrosis (ci), arteriolar hyalinosis (ah) and inflammation in the area of interstitial fibrosis and tubular atrophy (i-IFTA) from the 3- to the 12-month biopsy. Multivariable proportional odds logistic regression models revealed no association of HLA mismatch scores with progression of histologic lesions, except for ah and especially HLA-EMMA DRB1 [odds ratio (OR) = 1.10, 95% confidence interval (CI) 1.03–1.18]. Furthermore, the established associations of dnDSA formation with HLA mismatch and MVI (OR = 5.31, 95% CI 1.19–22.57) could be confirmed in our cohort. Conclusions These data support the association of HLA mismatch and alloimmune response, while suggesting that other factors contribute to early progression of chronic histologic lesions. [ABSTRACT FROM AUTHOR]

Copyright of Nefrologia is the property of Revista Nefrologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Medullary sponge kidney (MSK)is rare in association with glomerulonephritis. We report a patient with medullary sponge kidney, and the kidney biopsy revealed a diagnosis of IgA nephropathy. Case presentation: A 27-year-old female presented with hematuria and proteinuria, and imaging studies indicated the presence of medullary spongy kidney. With appropriate preparation, a kidney biopsy was performed. Considering the patient's clinical and pathological characteristics, the final diagnosis was determined to be medullary sponge kidney associated by IgA nephropathy. The combination of corticosteroids and angiotensin receptor blockers (ARBs) proved to be significantly effective in reducing proteinuria in the current case. To the best of our knowledge, this is the first reported case that demonstrates the coexistence of MSK and IgA nephropathy. Conclusions: Administering precise therapy based on renal pathology can potentially enhance outcomes for patients with renal conditions, necessitating the need for clinicians to be vigilant about differential diagnosis in order to reduce the rates of missed diagnoses and misdiagnosis. [ABSTRACT FROM AUTHOR]

Kidney involvement with resulting kidney failure leads to increased mortality in patients with multiple myeloma (MM). Cast nephropathy (CN), in particular, if left untreated, quickly leads to kidney failure requiring dialysis and has a very poor prognosis for the affected patient. The gold standard for diagnosing kidney involvement is a kidney biopsy. However, due to bleeding risk, this cannot be done in every patient. We recently reported that a quotient of urine light chain (LCurine) to glomerular filtration rate (eGFR) is a non-invasive diagnostic tool for patients with kidney involvement in MM. But this quotient has not yet been tested in everyday clinical practice. In this study, our LCurine/eGFR ratio was tested on 67 patients in two centers. Enrollment took place between January 2019 and September 2023. A total of 18 of the 67 patients had CN. With the threshold defined in our initial paper, we were able to show a sensitivity of 100% with a specificity of 85.7% for CN in patients with MM. As a result, the LCurine/eGFR quotient recognizes 100% of all CN and can therefore detect this group, which has a very poor prognosis, without the need for a kidney biopsy. [ABSTRACT FROM AUTHOR]

Rationale & Objectives: Diabetic kidney disease (DKD) is a significant complication of diabetes mellitus, often leading to kidney failure. The absence of well-defined factors prevents distinguishing DKD from non-diabetic kidney disease (non-DKD; alternative primary diagnosis identified on kidney biopsy). Study Design: Retrospective cohort study. Setting & Participants: This study assessed 1,242 patients with a history of diabetes from the Cleveland Clinic Kidney Biopsy Epidemiology Project between January 2015 and September 2021. Exposure: Proteinuria, retinopathy, A1c levels, and estimated glomerular filtration rate. Outcomes: Non-DKD, defined as an alternative primary diagnosis identified on kidney biopsy other than DKD. Analytical Approach: Multivariate logistic regression model with backward elimination method. Results: At the time of biopsy, the median (IQR) age was 63 (53-71 years) years, and 58.8% were men. The median hemoglobin A1c value was 6.7% (6.0%-8.1%), and the median serum creatinine level was 2.5 (1.6-3.9 mg/dL) mg/dL. Among 1,242 patients, 462 (37.2%) had DKD alone, and 780 (62.8%) had non-DKD. Among those with non-DKD, the most common diagnoses were focal segmental glomerulosclerosis (24%), global glomerulosclerosis otherwise not specified (13%), acute tubular necrosis (9%), IgA nephropathy (8%), antineutrophil cytoplasmic antibody vasculitis (7%), and membranous nephropathy (5%). Factors associated with having non-DKD on biopsy were having no retinopathy (vs retinopathy) (adjusted odds ratio [aOR], 3.98; 95% CI, 2.69-5.90), lower A1c levels (

Background: Diabetes mellitus (DM) is tightly associated with the increased prevalence of diabetic kidney disease (DKD). Nonetheless, severe renal function impairment and/or nephrotic range-proteinuria could also result from non-diabetic renal disease (non-DRD) among patients with DM. The ‘Gold standard’ for the differential diagnosis between DKD and non-DRD is kidney biopsy, although no real consensus exists. Thus, this study intends to associate the clinical and biochemical profile of patients with DM and renal disease with the histopathological data of kidney biopsy.In addition, we aimed to evaluate the role of kidney biopsy, especially when other causes, other than DM, are highly suspected among patients with DM and kidney disease. Methods: Thirty two patients with T2DM and nephrotic range levels of proteinuria or with co-existing factors pointing towards a non-diabetic origin of kidney disease were studied, retrospectively. All 32 patients underwent kidney biopsy and were classified according to histopathological findings into 3 groups: a) isolated diabetic kidney disease (DKD), b) non-diabetic kidney disease (NDKD) and c) mixed kidney disease (MKD). Results: Fifteen out of the 32 patients had findings of an isolated DKD, while 17 out of 32 patients suffered from NDKD (13 patients) or MKD (4 patients). DKD patients were younger (p = 0.016) and had a higher HbA1c value (p = 0.069, borderline statistical significance), while the NDKD patients had significantly shorter disease duration (p = 0.04). Furthermore, the incidence of diabetic retinopathy (DR) was lower among the NDKD patients (p

Gastric cancer ranks fourth among the most commonly diagnosed cancers, with over a million new cases diagnosed worldwide each year. Acute and chronic kidney damage are common in patients with malignant diseases and are associated with increased risk of complications and mortality. Rarely, acute renal insufficiency may result from bilateral infiltration of renal parenchyma by tumor cells from another organ. We present a case of a patient with clinical suspected gastric cancer and metastases to the kidneys leading to acute renal failure requiring hemodialysis. Despite gastric biopsies, no tumor cells were found, while histopathological examination of enlarged intra-abdominal lymph node biopsy material confirmed adenocarcinoma of signet ring cell originating from the digestive system. Stomach cancer was identified as the most likely primary site after the kidney biopsy was performed. To the best of our knowledge, no case of gastric cancer leading to kidney metastases and acute renal failure requiring renal replacement therapy was yet described. Multidisciplinary collaboration among oncologists, urologists, radiologists, pathologists, and nephrologists is essential for the optimal treatment outcome of these patients, who generally have a poor prognosis.

BackgroundMembranous nephropathy is an uncommon cause of nephrotic syndrome in pediatrics.MethodsWe reviewed our kidney biopsy records for patients ≤ 20 years of age with membranous nephropathy without evidence of systemic lupus erythematosus within 6 months of biopsy (January 1995-September 2020). Staining for PLA2R, NELL1, THSD7A, SEMA3B, EXT2 (3 biopsies), and IgG-subclass were performed.ResultsSixteen children (≤ 12 years) and 25 adolescents (13-20 years) were identified. Four children and 15 adolescents showed autoantigen positivity: PLA2R+/SEMA3B- (13), SEMA3B+/PLA2R+ (2), SEMA3B+/PLA2R- (1), NELL1 (1), EXT2+ (2), and THSD7A (0). Co-morbidities associated with PLA2R positivity included IPEX syndrome, active hepatitis B, Von Hippel Lindau syndrome, solitary kidney, type 1 diabetes, hyperuricemia, pregnancy (1), obesity (3), type II diabetes, H. pylori, viral prodrome, and nephrolithiasis. The SEMA3B+/PLA2R- adolescent was pregnant, the NELL1+ adolescent was obese, and the two EXT2+ adolescents eventually met the clinical criteria for lupus (4, 9 years post-biopsy). Co-morbidities among the remaining 24 patients included remote hepatitis B (2), Down's syndrome, lysinuric protein intolerance, recurrent UTIs, hypothyroidism, pregnancy (3), and obesity (2). Follow-up data was available for 12 children and 16 adolescents. Of the 12 children, 6 achieved complete remission, 4 achieved partial remission, and 2 had no response to treatment (1 transplant). Of the 16 adolescents, 4 achieved complete remission, 4 achieved partial remission, and 8 had no response to treatment (3 transplants). A child with "full-house" immunofluorescence staining achieved spontaneous disease remission.ConclusionOur non-lupus membranous nephropathy cohort represents one of the largest pediatric studies to date. A higher resolution version of the Graphical abstract is available as Supplementary information.

Abstract Aim The Swedish Renal Registry (SRR) is a unique national quality registry that monitors the clinical trajectory of patients with chronic kidney disease (CKD). We have validated the biopsy data registered in the SRR for IgA Nephropathy (IgAN) diagnosis. Methods In total 25% of all patients (n = 142), registered with IgAN in the SRR after having performed a kidney biopsy during 2015–2019, were randomly selected. We obtained original biopsy and medical records for 139 (98%) patients. We evaluated the IgAN diagnosis using a standardized template, calculated its positive predictive value (PPV) with 95% confidence interval (CI) and reported clinical features at the time of diagnosis. Results A histological and clinical diagnosis of IgAN was confirmed in 132 of the 139 patients, yielding a PPV of 95% (95% CI 90–98%). Median age was 46 years (range: 18–85) and the male:female ratio was 2.1:1. The median creatinine level was 123 µmol/L, with a corresponding estimated glomerular filtration rate (eGFR) level of 51 mL/min/1.73m2. Histological features of IgA deposits were seen in all patients, hypercellularity in 102/132 (77.2%), C3 deposits in 98/132 (72.4%) and C1q deposits in 27/132 (20.5%) of the cases. Conclusion Validating data is not research per se, but continuous validation of medical registries is an important feature necessary to ensure reliable data and the foundation of good epidemiological data for future research. Our validation showed a high PPV (95%) for IgAN diagnosis registered in the SRR. Clinical characteristics were consistent with previous reports. The biopsy data in the SRR will be a valuable resource in future IgAN research.

Introduction: Cyanotic nephropathy, a rare disease characterized by proteinuria, decreased estimated glomerular filtration rate, thrombocytopenia, polycythemia, and hyperuricemia, may occasionally be secondary to cyanotic congenital heart disease (CHD). There are currently no detailed diagnostic criteria or treatments for cyanotic nephropathy, owing to its extremely low incidence. Eisenmenger syndrome (ES) was initially defined by Paul Wood in pathophysiologic terms as “pulmonary hypertension (PH) at the systemic level, caused by a high pulmonary vascular resistance, with a reversed or bidirectional shunt at the aorto-pulmonary, ventricular, or atrial level.” It typically develops in the presence of large, unrepaired atrial or ventricular septal defects, arterial shunts, or complex forms of CHD and is the most severe hemodynamic phenotype of pulmonary arterial hypertension associated with CHD. This study aimed to outline the case of an ES patient who developed cyanotic nephropathy and successfully achieved clinical remission through primary disease treatment and symptomatic management. Overall, this case expands our understanding of cyanotic nephropathy and lays a theoretical reference for the treatment of ES. Case Presentation: A 33-year-old Chinese female attended the outpatient department with abnormal urine test results over the past two and a half years. Following a comprehensive medical history collection, she underwent the necessary tests. Cardiac color ultrasound displayed a significant widening of the pulmonary artery and PH (severe), as well as mild tricuspid regurgitation and patent ductus arteriosus. The results of the kidney biopsy, combined with clinical findings, suggested a high risk of polycythemia-related kidney disease. She was eventually diagnosed with cyanotic nephropathy and ES. Her symptoms were relieved following symptomatic treatment, such as the administration of ambrisentan, febuxostat, and home oxygen therapy. Her follow-up visit at 6 months demonstrated improvements in hyperuricemia and a significant increase in physical strength. Conclusion: Cyanotic nephropathy is a rare condition in adults. Kidney biopsy remains the gold standard of diagnosis for various nephropathies. Active treatment of CHD and alleviating hypoxia may be pivotal for the treatment of cyanotic nephropathy.

Background: The first spatially resolved transcriptomics platforms, GeoMx (Nanostring) and Visium (10x Genomics) were launched in 2019 and were recognized as the method of the year by Nature Methods in 2020. The subsequent refinement and expansion of these and other technologies to increase -plex, work with formalin-fixed paraffin-embedded tissue, and analyze protein in addition to gene expression have only added to their significance and impact on the biomedical sciences. In this perspective, we focus on two platforms for spatial transcriptomics, GeoMx and Visium, and how these platforms have been used to provide novel insight into kidney disease. The choice of platform will depend largely on experimental questions and design. The application of these technologies to clinically sourced biopsies presents the opportunity to identify specific tissue biomarkers that help define disease etiology and more precisely target therapeutic interventions in the future. Summary: In this review, we provide a description of the existing and emerging technologies that can be used to capture spatially resolved gene and protein expression data from tissue. These technologies have provided new insight into the spatial heterogeneity of diseases, how reactions to disease are distributed within a tissue, which cells are affected, and molecular pathways that predict disease and response to therapy. Key Message: The upcoming years will see intense use of spatial transcriptomics technologies to better define the pathophysiology of kidney diseases and develop novel diagnostic tests to guide personalized treatments for patients.

Abstract Background The kidney biopsy is a routine procedure. Once an indication has been established, the benefit–risk balance may be considered. Sometimes, even with effective treatment, a severe complication may develop. Case presentation We present the case of a Caucasian 20-year-old young woman admitted to investigating and treating acute kidney injury. Renal involvement was characterized by kidney damage requiring hemodialysis treatment, positive immunologic testing, 0.5 g/day proteinuria, and microscopic hematuria. Contraindications were excluded, so an ultrasound-guided kidney biopsy was performed. To reduce the bleeding complication, Octostim (desmopressin) was administered. There were no direct complications following the kidney biopsy, so we continued the immunosuppressive treatment. Histologically founded thrombotic microangiopathy. However, 1 week later, severe bleeding developed with the need for urgent surgical left kidney removal. Conclusion Kidney biopsy can be considered a routine procedure, and various bleeding episodes are most common in terms of complications, the detection of which is essential. Delayed bleeding complications are rare and can be caused by minor injuries. Our young patient had no injury during the hospitalization. We hypothesized that the developed serious and delayed bleeding complication resulted from effective immunosuppressive treatment. To the best of our knowledge, this is the first such case to date. However, renal biopsy in the case of thrombotic microangiopathy requires caution.

In the course of this research, complement activation and antiphospholipid antibody (aPL) levels were investigated in individuals suffering from lupus nephritis. In this study, a retrospective analysis was performed on individuals who had kidney biopsies that were positive for LN. For the purpose of determining the levels of anticardiolipin antibodies (aCLs) and anti-ß2-glycoprotein I (anti-ß2-GPI) antibodies belonging to the IgM, IgA, and IgG classes, thorough research was carried out. Concurrent with the kidney biopsy, information on clinical symptoms and pathology was also collected. Nearly half (45.8% to be exact) of the forty people with LN who participated in the study tested positive for antiphospholipid antibodies (aPLs). "Individuals who were diagnosed with LN and did not possess any antiphospholipid antibodies (aPLs) displayed elevated levels of glomerulus C1q, decreased levels of serum complement proteins C3 and C4, increased levels of hematuria, and higher scores on the SLEDAI (P<0.05). It was shown that there was an inverse association between the levels of C3 and C4 in the blood and the IgG-aCL (r=-0.31, P=0.007; r=-0.36, P=0.028). It was shown that there is a significant link between the levels of IgG-aCL and the deposits of glomerulus C4 (r=0.31, P=0.043)." This connection turned out to be essential. The findings presented here indicate that IgG-aCLs have the potential to exacerbate LN and activate complement pathways. [ABSTRACT FROM AUTHOR]

Introduction: As life expectancy increases, geriatric patients are affected by kidney disease; nephrologists are increasingly faced with a geriatric population requiring kidney biopsy (KB). Objective: To analyze geriatric patients' histopathological diagnosis, clinical presentation, and biopsy indications. Methods: All patients who underwent native KB in our center between 2017 and 2023 were included. Histopathological diagnosis, clinical presentation, and biopsy indications in geriatric patients were compared with the non-geriatric group. Results: Among the 511 included patients, those older than 65 years (n:81, 15.8%) were analyzed and compared with those aged 18-64 years (n:430, 84.2%). The median age of the patients was 68 (IQR 66-72) years, and 56.8% were male. Non-nephrotic proteinuria was the most common biopsy indication in the geriatric group (27.2%, p: 0.004). The most frequent primer glomerular disease (PGD) was membranous glomerulonephritis (MGN). MGN (33.3%) was the leading cause of nephrotic syndrome. The geriatric group's most frequent Primary Glomerular Disease (PGD) histopathological patterns were MGN, FSGS, and pauci-immune GN. The frequency of acute kidney injury was significantly higher in the geriatric group (19.8%) compared to the nongeriatric group (11.6%) (p = 0.046). Secondary glomerular diseases (SGD) were more common than PGD and tubulointerstitial nephritis. Diabetic nephropathy was the most common SGD in both the geriatric and non-geriatric groups (24.7% and 15.6%). Conclusions: The spectrum of biopsyproven kidney disease in the geriatric patients seen in our study differs from that of the non-geriatric population. KB provides valuable information with diagnostic, therapeutic, and prognostic implications in these patients. [ABSTRACT FROM AUTHOR]

Background: Trefoil factor 3 (TFF-3) is a peptide that restores the epithelium as protection against injury. Recently, TFF-3 was shown to be expressed in kidney tubular cells and was associated with fbrosis. We aimed to determine whether TFF-3 is associated with kidney outcomes. Methods: We evaluated TFF-3 expression and its relationship with mesangial hypercellularity, endocapillary hypercellularity, segmental glomerulosclerosis, tubular atrophy/interstitial fbrosis and crescents (MEST-C) score, tumor necrosis factor alpha (TNF-α), interleukin-10 (IL-10), and transforming growth factor-beta (TGF-β) expression in the kidney. We included 28 immunoglobulin A (IgA) patients with initial estimated glomerular fltration rate (eGFR) ≥ 30 mL/min/1.73m2 and proteinuria ≥0.5 g/day. Kidney biopsies were scored using MEST-C and were stained for TFF-3, IL10, TGF-β, and TNF-α. Results: Mean patient age was 37.0 ± 13.8 years and eGFR was 74.6 ± 41.2 mL/min/1.73 m2 . Patients were followed for 9.1 ± 3.6 years. Trefoil factor 3 was positive in 67.9% of patients exclusively in tubular cells. Tumor growth factor-β was also observed only in tubular cells in 71.4% of patients and was higher in TFF-3-positive patients (89.5% vs. 22.2%, P < .05). When patients with and without TFF-3 staining were compared, there was no diference in age, eGFR, albumin, or proteinuria. Yearly eGFR change was also similar (−0.5 ± 2.3 vs. −1.3 ± 2.4 mL/min/1.73 m2, P = .44). Trefoil factor 3 was not associated with kidney survival. The MEST-C score was not correlated with TFF-3. Trefoil factor 3 staining showed correlation with TGF-β but was not associated with kidney survival in IgA patients. Conclusion: Findings of the study imply TFF-3 is not a marker of permanent damage but might simply be a marker of the repair of ongoing tubular injury. [ABSTRACT FROM AUTHOR]

Simulation is a technique to replace and amplify real experiences with guided ones that evoke or replicate substantial aspects of the real world in a fully interactive fashion. In nephrology (a particularly complex specialty), simulation can be used by patients, nurses, residents, and attending physicians alike. It allows one to learn techniques outside the stressful environment of care such as central venous catheter placement, arteriovenous fistula management, learning about peritoneal dialysis, or performing a kidney biopsy. Serious games and virtual reality are emerging methods that show promise. Simulation could also be important in relational aspects of working in a team or with the patient. The development of simulation as a teaching tool in nephrology allows for maintaining high-quality training for residents, tailored to their future practice, and minimizing risks for patients. Additionally, this education helps nephrologists maintain mastery of technical procedures, making the specialty attractive to younger generations. Unfortunately, the inclusion of simulation training programmes faces occasional logistical or funding limitations that universities must overcome with the assistance and innovation of teaching nephrologists. The impact of simulation-based teaching on clinical outcomes needs to be investigated in clinical studies. [ABSTRACT FROM AUTHOR]

We present a case of a 58-year-old man with a history of laryngo-pharyngectomy including bilateral thyroidectomy due to hypopharyngeal cancer presenting with lethargy, acute kidney failure, and hypercalcemia. Milk alkali syndrome was diagnosed given the history of high-dose calcium / vitamin D supplementation after ruling out other causes of hypercalcemia. After initial treatment with normal saline, furosemide and denosumab, the patient developed severe symptomatic hypocalcemia as a rare adverse effect of denosumab. [ABSTRACT FROM AUTHOR]

Aim: The Swedish Renal Registry (SRR) is a unique national quality registry that monitors the clinical trajectory of patients with chronic kidney disease (CKD). We have validated the biopsy data registered in the SRR for IgA Nephropathy (IgAN) diagnosis. Methods: In total 25% of all patients (n = 142), registered with IgAN in the SRR after having performed a kidney biopsy during 2015–2019, were randomly selected. We obtained original biopsy and medical records for 139 (98%) patients. We evaluated the IgAN diagnosis using a standardized template, calculated its positive predictive value (PPV) with 95% confidence interval (CI) and reported clinical features at the time of diagnosis. Results: A histological and clinical diagnosis of IgAN was confirmed in 132 of the 139 patients, yielding a PPV of 95% (95% CI 90–98%). Median age was 46 years (range: 18–85) and the male:female ratio was 2.1:1. The median creatinine level was 123 µmol/L, with a corresponding estimated glomerular filtration rate (eGFR) level of 51 mL/min/1.73m2. Histological features of IgA deposits were seen in all patients, hypercellularity in 102/132 (77.2%), C3 deposits in 98/132 (72.4%) and C1q deposits in 27/132 (20.5%) of the cases. Conclusion: Validating data is not research per se, but continuous validation of medical registries is an important feature necessary to ensure reliable data and the foundation of good epidemiological data for future research. Our validation showed a high PPV (95%) for IgAN diagnosis registered in the SRR. Clinical characteristics were consistent with previous reports. The biopsy data in the SRR will be a valuable resource in future IgAN research. [ABSTRACT FROM AUTHOR]

Background: Tubulointerstitial lesions and glomerular inflammation severity have been shown to correlate with proteinuria in children with IgA nephropathy (cIgAN). However, there is a lack of data regarding severity of histopathologic findings in cIgAN in patients with minimal to absent proteinuria since kidney biopsy indications are not well defined in these cases. Methods: Twenty-eight cIgAN patients with kidney biopsy from 4 different centers in Paris (France) and Montreal (Canada) with a urine protein/creatinine ratio (UPCr) ≤ 0.03 g/mmol and a normal estimated glomerular filtration rate (eGFR > 90 ml/min/1.73 m2) on the day of kidney biopsy prior to treatment were included. Results: Median age was 11.82 (9.32–13.45) years, and median follow-up was 4 years (2.87–6.53). At time of biopsy, median eGFR was 116 (102.3–139.7) ml/min/1.73 m2, and median UPCr was 0.02 (0.011–0.03) g/mmol. Microscopic or macroscopic hematuria was present in 35.7% and 64.3% of cases, respectively. Kidney biopsy microscopy analysis showed mesangial (M1), endocapillary (E1), or extracapillary (C1) hypercellularity in 53.5%, 32.1%, and 7.1% of patients, respectively. Chronic histological lesions were also present: glomerulosclerosis (S1) in 42.8% and tubular atrophy/interstitial fibrosis in 7.1%. Podocytopathic features were detected in 21.4%. An ACE inhibitor or immunosuppressive therapy (IS) was prescribed in 42.8% and 21.4% of these patients respectively. One-third (35.7%) received no treatment. At last follow-up, median eGFR was 111.9 (90.47–136.1) ml/min/1.73 m2, and median UPCr was 0.028 (0.01–0.03) g/mmol. Conclusion: cIgAN with minimal proteinuria at time of biopsy might be linked with acute and chronic glomerular lesions. [ABSTRACT FROM AUTHOR]

Background The 2021 clinical guidelines of the Kidney Disease: Improving Global Outcomes emphasize the importance of the histological activity index (AI) in the management of lupus nephritis (LN). Patients with LN and a high AI have poor renal outcomes and high rates of nephritic relapse. In this study we constructed prediction models for the AI in LN. Methods The study population comprised 337 patients diagnosed with LN using kidney biopsy. The participants were randomly divided into training and testing cohorts. They were further divided into high-activity (AI >2) and low-activity (AI ≤2) groups. This study developed two clinical prediction models using logistic regression and least absolute shrinkage and selection operator (LASSO) analyses with laboratory test results collected at the time of kidney biopsy. The performance of models was assessed using 5-fold cross-validation and validated in the testing cohort. A nomogram for individual assessment was constructed based on the preferable model. Results Multivariate analysis showed that higher mean arterial pressure, lower estimated glomerular filtration rate, lower complement 3 level, higher urinary erythrocytes count and anti-double-stranded DNA seropositivity were independent risk factors for high histologic activity in LN. Both models performed well in the testing cohort regarding the discriminatory ability to identify patients with an AI >2. The average area under the curve of 5-fold cross-validation was 0.855 in the logistic model and 0.896 in the LASSO model. A webtool based on the LASSO model was created for clinicians to enter baseline clinical parameters to produce a probability score of an AI >2. Conclusions The established nomogram provides a quantitative auxiliary tool for distinguishing LN patients with a high AI and helps physicians make clinical decisions in their comprehensive assessment. [ABSTRACT FROM AUTHOR]

Les gammapathies monoclonales de signification rénale (MGRS pour Monoclonal gammopathy of renal significance) sont définies par l'association d'un petit clone B et d'une néphropathie induite par l'immunoglobuline monoclonale (IgMo) sécrétée. La néphrotoxicité des IgMo est dictée par leurs caractéristiques physicochimiques et fait intervenir des mécanismes directs (dépôt) ou indirects. Les néphropathies des MGRS sont classées en trois groupes selon la composition et l'aspect ultra structural des dépôts, la plus fréquente étant l'amylose AL, définie par des dépôts organisés fibrillaires de chaînes légères (CL) monoclonales. Le diagnostic, évoqué par les manifestations rénales et extra-rénales, nécessite une confirmation histologique avec étude en microscopie optique, immunofluorescence et microscopie électronique d'une biopsie rénale. La précocité du diagnostic et l'obtention rapide d'une réponse hématologique profonde par un traitement ciblant le clone conditionnent le pronostic. Un bilan immunologique et hématologique approfondi est donc requis pour caractériser l'IgMo pathogène (électrophorèse et immunofixation sérique et urinaire, dosage des CL libres sériques) et identifier le clone sous-jacent, souvent plasmocytaire (étude de la moelle osseuse en cytométrie de flux, cytogénétique). Cette revue fait le point sur les avancées récentes dans le diagnostic des MGRS en mettant l'accent sur les nouvelles méthodes (biologie moléculaire, protéomique) qui devraient faciliter la prise en charge de ces pathologies rares et complexes. Monoclonal gammopathy of renal significance (MGRS) refers to a small B-cell clone associated with renal disease induced by the secreted monoclonal Ig (MIg). Renal lesions, independent of the tumor burden, are governed by the MIg characteristics and involve either direct (deposition) or indirect mechanisms (autoantibody activity, complement activation). The spectrum of MGRS encompasses glomerular and tubulo-interstitial lesions classified into 3 categories according to the composition and ultra-structural appearance of deposits. The most frequent is AL amyloidosis, defined by organized fibrillar deposits of monoclonal light chains (LC). The diagnosis of each specific nephropathy, suggested by the analysis of renal (composition of proteinuria) and extra-renal manifestations, is confirmed in most cases by light, immunofluorescence and electron microscopy studies of a kidney biopsy. Early diagnosis and rapid achievement of a deep haematological response through clone-targeted chemotherapy determine the outcomes. A detailed hematologic workup is warranted to characterize the MIg (serum and urine electrophoresis and immunofixation, serum free LC) and to identify the underlying clone (bone marrow flow cytometry, cytogenetics).This review focuses on the recent advances in the diagnosis of MGRS, highlighting the value of novel techniques (molecular biology, proteomics) which should facilitate the management of these rare and complex disorders. [ABSTRACT FROM AUTHOR]

Background: The kidney biopsy is a routine procedure. Once an indication has been established, the benefit–risk balance may be considered. Sometimes, even with effective treatment, a severe complication may develop. Case presentation: We present the case of a Caucasian 20-year-old young woman admitted to investigating and treating acute kidney injury. Renal involvement was characterized by kidney damage requiring hemodialysis treatment, positive immunologic testing, 0.5 g/day proteinuria, and microscopic hematuria. Contraindications were excluded, so an ultrasound-guided kidney biopsy was performed. To reduce the bleeding complication, Octostim (desmopressin) was administered. There were no direct complications following the kidney biopsy, so we continued the immunosuppressive treatment. Histologically founded thrombotic microangiopathy. However, 1 week later, severe bleeding developed with the need for urgent surgical left kidney removal. Conclusion: Kidney biopsy can be considered a routine procedure, and various bleeding episodes are most common in terms of complications, the detection of which is essential. Delayed bleeding complications are rare and can be caused by minor injuries. Our young patient had no injury during the hospitalization. We hypothesized that the developed serious and delayed bleeding complication resulted from effective immunosuppressive treatment. To the best of our knowledge, this is the first such case to date. However, renal biopsy in the case of thrombotic microangiopathy requires caution. [ABSTRACT FROM AUTHOR]

Kidney biopsy (KB) has become essential in the nephrologist's approach to kidney diseases, both for diagnosis, treatment, and prognosis. Our objective is to describe the preliminary results of KBs in Niger, one of the poorest countries in the world. This is a descriptive cross-sectional study that took place over 36 months in the nephrology/dialysis department of the Zinder National Hospital. Biopsy results were obtained in less than 5 working days. Patients were responsible for covering the cost of the kidney biopsy. The data collected were analyzed using Epi Info V7 software. We performed 120 kidney biopsies during the study period. The average age of the patients was 35 years ± 15.4 [5–68]. The male/female sex ratio was 2:1. Patients' medical history included herbal medicine use in 33% of cases and high blood pressure in 27.5% of cases. Proteinuria was present at a rate of ≥3 g/24 h in 46.6% of them. The primary indication for kidney biopsy was glomerular syndrome in 62.5% of cases, including 50% with nephrotic syndrome. All kidney biopsies were performed with real-time ultrasound guidance, using an automatic gun fitted with a 16G needle. Regarding complications, macroscopic hematuria was present in 12.5% of cases. Inadequate kidney biopsy was infrequent (5.8% of cases). The most common findings were (i) glomerular diseases (58.4%), such as membranoproliferative glomerulonephritis (13.3%), focal-segmental glomerulosclerosis (10.6%), lupus nephritis (8.8%), minimal change disease (8%), and membranous nephropathy (2.7%), and (ii) tubulointerstitial changes (31.8%). Diabetic nephropathy was rare (2.6%), as was IgA nephropathy (0.9%). We have demonstrated that implementing a sustainable kidney biopsy program in a very poor country is feasible, thanks to the dedication of a specialized renal pathologist. Having a clear diagnosis can assist in properly treating these renal patients according to international guidelines, thereby delaying the progression to end-stage kidney disease. [ABSTRACT FROM AUTHOR]

Background : Cystinosis is a rare autosomal recessive lysosomal disorder that mainly affects the kidney and eye. Early treatment with cysteamine significantly improves the prognosis. However, early diagnosis of cystinosis, especially the juvenile nephropathic form, remains challenging because typical symptoms only become apparent in adulthood. We herein describe a 13-year-old girl who presented with proteinuria only but was diagnosed with juvenile nephropathic cystinosis based on multinucleated podocytes in her kidney biopsy specimen. We also studied the nephropathology of another case to determine the features of the multinucleated podocytes. Case diagnosis: A previously healthy 13-year-old girl presented to our hospital because proteinuria had been detected in her school urine screening. She had been noted to have proteinuria on her school urine screening when she was 11 years of age but there was no consultation with her physician at that time. She was asymptomatic and had no other abnormalities on examination other than a relatively high urinary β-2 microglobulin level. Her kidney biopsy showed 15 multinucleated podocytes in 34 glomeruli, and the mean number of nuclei per multinucleated podocyte was 4.4. Ophthalmological examination showed cystine crystals in her cornea. Her white blood cell cystine level was high, and she was diagnosed with juvenile nephropathic cystinosis. She started oral cysteamine treatment and showed almost no progression of the disease after 2 years. In another patient with juvenile nephropathic cystinosis, there were 25 multinucleated podocytes in 63 glomeruli, and the mean number of nuclei per multinucleated podocyte was 2.9. Conclusion: Early diagnosis is crucial to improve the prognosis of patients with cystinosis. This report emphasizes the importance of recognizing the unique pathological feature of multinucleated podocytes as an essential clue to the diagnosis of cystinosis. [ABSTRACT FROM AUTHOR]

Chronic changes on kidney biopsy specimens include increasing amounts of arteriosclerosis, glomerulosclerosis, interstitial fibrosis and tubular atrophy, enlarged nephron size, and reduced nephron number. These chronic changes are difficult to accurately assess by visual inspection but are reasonably quantified using morphometry. This review describes the various patient populations that have undergone morphometric analysis of kidney biopsies. The common approaches to morphometric analysis are described. The chronic kidney disease outcomes associated with various chronic changes by morphometry are also summarized. Morphometry enriches the characterization of chronicity on a kidney biopsy and this can supplement the pathologist's diagnosis. Artificial intelligence image processing tools are needed to automate the annotations needed for practical morphometric analysis of kidney biopsy specimens in routine clinical care. [ABSTRACT FROM AUTHOR]

Background. Type 2 diabetes mellitus (T2DM) with chronic kidney disease (CKD) poses a serious health threat and becomes a new challenge. T2DM patients with CKDfall into three categories, diabetic nephropathy (DN), non-diabetic kidney disease (NDKD), and diabetic nephropathy plus non-diabetic kidney disease (DN C NDKD), according to kidney biopsy. The purpose of our study was to compare the clinical characteristics and kidney outcomes of DN, NDKD, and DN C NDKD patients. Methods. Data on clinical characteristics, pathological findings, and prognosis were collected from June 2016 to July 2022 in patients with previously diagnosed T2DM and confirmed DN and or NDKD by kidney biopsy at Tongji Hospital in Wuhan, China. The endpoint was defined as kidney transplantation, dialysis, or a twofold increase in serum creatinine. Results. In our 6-year retrospective cohort research, a total of 268 diabetic patients were admitted and categorized into three groups by kidney biopsy. The 268 patients were assigned to DN (n=74), NDKD (n=109), and DN C NDKD (n=85) groups. The most frequent NDKD was membranous nephropathy (MN) (n = 45,41.28%). Hypertensive nephropathy was the most common subtype in the DN+NDKD group (n = 34,40%). A total of 34 patients (12.7%) reached the endpoint. The difference between the Kaplan-Meier survival curves of the DN, NDKD, and DN C NDKD groups was significant (p < 0:05). Multifactorial analysis showed that increased SBP [HR (95% CI): 1.018(1.002-1.035), p=0:025], lower Hb [HR(95% CI): 0.979(0.961-0.997), p=0:023], higher glycosylated hemoglobin [HR(95% CI): 1.338(1.080-1.658), p=0:008] and reduced serum ALB [HR(95% CI): 0.952(0.910-0.996), p=0:032] were risk factors for outcomes in the T2DM patients with CKD. Conclusions. This research based on a Chinese cohort demonstrated that the risk of endpoint events differed among DN, NDKD, and DN+NDKD patients. In T2DM patients with CKD, DN patients displayed worse kidney prognosis than those with NDKD or DN C NDKD. Increased SBP, higher glycosylated hemoglobin, lower Hb, and decreased serum ALB may be correlated with adverse kidney outcomes in T2DM patients. [ABSTRACT FROM AUTHOR]

IntroductionKimura’s disease (KD) is a rare chronic inflammatory disorder characterized by subcutaneous lymphoid hyperplasia with peripheral eosinophilia. Kidney involvement is reported in 15%–18% of adult patients with KD, in many cases as nephrotic syndrome. We present a case of overlapping membranous nephropathy and IgA nephropathy associated with KD.Case reportA 27-year-old man was admitted with a history of bilateral leg edema for the last 2 months and concomitant progressive increase of cervical mass and fever. Laboratory findings were as follows: peripheral leukocyte count, 10,080/mm³; eosinophils, 3,200/mm³ (31.7%); serum creatinine, 0.83 mg/dL; and eGFR: 140 mL/min per 1.73 m2. Urinalysis revealed the presence of hematuria and proteinuria and the following results: 24-h proteinuria, 12.9 g; serum albumin, 1.3 g/dL; and elevated IgE level, 750 kU/L. Serologies for hepatitis B, hepatitis C, HIV, and VDRL were all negative. Complement C3 and C4 levels were normal. No monoclonal protein was detected in blood and urine. Parasite infestation was discarded. A biopsy of the cervical lymph node revealed eosinophilic lymphoid hyperplasia, suggesting KD. A kidney biopsy revealed findings consistent with the overlapping of membranous nephropathy with IgA nephropathy. The patient was treated for KD with prednisone 1 mg/kg/d with progressive dose tapering and posterior association of methotrexate 15 mg/week. A renin–angiotensin system inhibitor was prescribed for nephrotic syndrome. The cervical mass regressed, and proteinuria achieved partial remission, with an increase in serum albumin level and normalization of eosinophils and IgE levels.ConclusionAlthough uncommon, kidney involvement must be considered in patients with KD. Glomerular diseases are the most frequent form of kidney injury.

IntroductionPatients with systemic lupus erythematosus are prone to develop cardiovascular disease (CVD), and have increased morbidity and mortality.MethodsWe conducted a retrospective analysis on lupus nephritis patients to assess the occurrence and predictors of major adverse cardiovascular events (MACE). Data were collected from patients who underwent kidney biopsy between 2005 and 2020. Statistical analysis was performed to unveil correlations.Results91 patients were analyzed in this period, with a mean age of 37.3 ± 12.3 years and 86% being female. The mean follow-up time was 62 ± 48 months. 15.38% of the patients underwent at least one MACE. Two patients deceased of CVD. Increased age (35.81 ± 11.14 vs 45.5 ± 15.11 years, p=0.012) entailed a higher occurrence of MACEs. Neutrophil count (5.15 ± 2.83 vs 7.3 ± 2.99 Giga/L, p=0.001) was higher, whereas diastolic blood pressure (DBP) was lower (89.51 ± 10.96 vs 78.43 ± 6.9 mmHg, p

A kidney biopsy was performed in a 64-year-old woman with type 2 diabetes mellitus and less than 1 g of proteinuria who rapidly progressed to end-stage renal failure after approximately 2 years of treatment with two dipeptidyl peptidase 4 (DPP-4) inhibitors for type 2 diabetes mellitus. The biopsy revealed not only a coincidental diagnosis of renal cell carcinoma, which was not evident on pre-biopsy computed tomography, but also severe thrombotic microangiopathy (TMA)-like glomerular endothelial cell damage in the noncancerous areas. These results suggest that DPP4 inhibitors may have been involved in two kidney diseases.

Individuals with lupus nephritis (LN) are at high risk of adverse maternal and fetal outcomes in pregnancy. Outside of pregnancy, proliferative lesions on kidney biopsies are associated with disease progression, but these have not been consistently associated with increased risk in pregnancy. This retrospective, single-center study examines how histologic findings, the timing from kidney biopsy to pregnancy, and the clinical features in the first trimester are associated with preterm birth among individuals with LN. Among 35 deliveries in 31 women, the mean gestational age at delivery was 33.8 weeks. The presence of a urine protein-to-creatinine ratio >0.5 g/g in the first trimester was associated with preterm delivery (81% vs. 36%, p = 0.04). Preterm birth was more common in individuals with glomerular crescents on biopsy (89% in those with >20% crescents vs. 50% in those with

Introduction: Glomerular diseases (GDs) have varied presentations in adults. The spectrum varies from benign to aggressive presentations. Materials and Methods: We conducted an observational prospective study at a tertiary care teaching hospital in North India from July 2020 to June 2022 to evaluate GD's spectrum and clinicopathological correlation. All kidney biopsies conducted during this period were considered as per inclusion and exclusion criteria, and detailed history and clinical examination were done. Results: One hundred and twenty-six kidney biopsies were evaluated as per inclusion and exclusion criteria. The mean age was 37.77 ± 17.73 years. Overall, the male-to-female ratio was 2.3:1 while the male-to-female ratio in lupus nephritis (LN) is 0.37:1. Primary GD (PGD) dominated among males whereas secondary GD (SGD) was more common in females. Nephrotic syndrome (NS, 44.5%) and acute kidney injury 27% were the most common clinical syndromes. The most common symptoms were edema and frothuria in NS (70%), and hematuria in acute nephritic syndrome 59%, whereas fatigue and gastrointestinal symptoms (44%) dominated in SGDs. The PGD-to-SGD ratio was 61.1:38.9. The most common PGD was immunoglobulin A nephropathy (IgAN, 22.1%), followed by minimal change disease (MCD, 20.8%), whereas LN (22.5%) was the prominent SGD, with Class IV + V (36.4%) being most common. Conclusion: GDs have a multitude of presentations – from asymptomatic urinary abnormalities to crescentic ones. IgAN and MCD were the most common of PGD whereas LN was the most common SGD.

Introduction: Monoclonal gammopathy of renal significance (MGRS) is characterized by monoclonal immunoglobulin deposition in kidneys. However, monoclonal immunoglobulin and responsible clone(s) are not always detectable. Treatment response and kidney outcome of MGRS without detectable clones remain unclear. Methods: In this single-center, retrospective cohort study, we identified MGRS without detectable clones from our biopsy repository between 2010 and 2022. We investigated the correlations between treatment regimens and kidney outcomes defined by proteinuria and estimated glomerular filtration rate (eGFR), and the impact of repeat kidney biopsy. Results: Our study cohort included 29 cases (27 native kidney and 2 transplant allograft biopsies) of MGRS without detectable clones. At diagnosis, median serum creatinine was 1.8 mg/dl (interquartile range [IQR] 1.3–2.7), with proteinuria 4.6 g/gCr (IQR 2.3–7.9). Treatment regimens were variable: 6 (21%) received conservative therapy, 13 (45%) received plasma cell clone-directed therapy, 8 (28%) received lymphocytic clone-directed therapy, and 2 (7%) received nonclone-directed immunosuppressive therapy. Of 24 patients with proteinuria >0.5 g/gCr at diagnosis, 9 (38%) and 6 (25%) achieved complete response (CR) and partial response (PR), respectively. If interstitial fibrosis and tubular atrophy (IFTA) was >50% at the initial biopsy, less proportion of patients achieved CR. Six of 7 repeat biopsies showed progression of chronic changes (e.g., IFTA) but provided limited information on treatment response. Conclusion: Treatment regimens and outcomes of MGRS without detectable clones were extremely variable. Repeat biopsy provided limited information to assess disease activity or the need for additional treatment. More sensitive tools are needed to detect clones and to assess treatment response.

Abstract Background Fibronectin glomerulopathy is a rare genetic nephropathy with only a few cases of post-transplant recurrence being reported previously. We highlight a case that was initially misdiagnosed and emphasize the importance of full immunofluorescence and electron microscopy evaluation in allograft biopsies. Case presentation A 36-year-old male with a history of end-stage kidney disease secondary to biopsy-proven type 1 membranoproliferative glomerulonephritis (MPGN) status-post living unrelated donor kidney transplant 12 years prior, presented with increasing creatinine and proteinuria. Biopsy was performed and was consistent with fibronectin glomerulopathy. Subsequent genetic testing revealed an FN1 mutation, the primary gene associated with this condition. Conclusions Full histologic evaluation of the allograft biopsy corrected the diagnosis and additionally suggested that the patient's mother, who had expired in her 30s and had received a diagnosis of type 1 MPGN on autopsy, likely also had fibronectin glomerulopathy, enabling appropriate genetic counseling for the family.

Abstract Background To classify the different clinical phenotypes and compare the distinct prognoses of microscopic polyangiitis (MPA). Methods A retrospective analysis of 436 patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV) from 2015 to 2022 was conducted in our center, of which 90 patients were diagnosed with MPA and underwent renal biopsy. Results Among the 90 MPA patients, 63% were female, and the median age at onset was 63 years (25th–75th percentile: 58–68). The median follow-up time was 26 months (25th–75th percentile: 10–53). We identified four subtypes: renal impairment type (cluster 1, 39%), pure type (cluster 2, 22%), systemic inflammation type (cluster 3, 26%), and rapid progress type (cluster 4, 13%). Cluster 1, characterized by renal dysfunction at onset (80%), demonstrated poor prognoses with only 26% achieved complete remission (CR), 11% dying, and 19% developing renal failure. In contrast, patients in cluster 2, exclusively female, most had only kidney involvement showed the best prognoses with 55% achieving CR and none experiencing death or renal failure within 10 years. Cluster 3 mostly consisted of males; high fever and C-reactive protein levels were the primary characteristics. These cases exhibited moderate prognoses with 53% achieving CR, 9% dying, and 4% developing renal failure. Finally, patients in cluster 4, which was characterized by rapidly progressive glomerulonephritis, had the worst prognoses, with none achieving CR, 8% dying, and 75% developing renal failure despite aggressive treatment. Conclusions MPA is classified into four subtypes with distinct clinical manifestations and prognoses.

Abstract Fabry disease (FD) is an X-linked inherited lysosomal disorder due to a deficiency of the enzyme alpha-galactosidase A (α-gla) due to mutations in the GLA gene. These mutations result in plasma and lysosome accumulation of glycosphingolipids, leading to progressive organ damage and reduced life expectancy. Due to the availability of specific disease-modifying treatments, proper and timely diagnosis and therapy are essential to prevent irreversible complications. However, diagnosis of FD is often delayed because of the wide clinical heterogeneity of the disease and multiple organ involvement developing in variable temporal sequences. This observation is also valid for renal involvement, which may manifest with non-specific signs, such as proteinuria and chronic kidney disease, which are also common in many other nephropathies. Moreover, an additional confounding factor is the possibility of the coexistence of FD with other kidney disorders. Thus, suspecting and diagnosing FD nephropathy in patients with signs of kidney disease may be challenging for the clinical nephrologist. Herein, also through the presentation of a unique case of co-occurrence of autosomal dominant polycystic kidney disease and FD, we review the available literature on cases of coexistence of FD and other renal diseases and discuss the implications of these conditions. Moreover, we highlight the clinical, laboratory, and histological elements that may suggest clinical suspicion and address a proper diagnosis of Fabry nephropathy.

INTRODUCTION: There are limited reports on kidney biopsy findings in patients with mantle cell lymphoma (MCL). METHODS: We initiated a multi-institutional, retrospective review of kidney biopsy findings in patients with active and treated MCL. RESULTS: A total of 30 patients with MCL and kidney biopsies were identified, with a median age of 67 (range 48-87) years, 73% of whom were men. A total of 20 patients had active MCL at the time of biopsy, of whom 14 (70%) presented with acute kidney injury (AKI), proteinuria and/or hematuria, and biopsy findings potentially attributable to lymphoma. Of the 14, 11 had immune complex (IC) or complement-mediated (C3) disease including proliferative glomerulonephritis (GN) with monotypic Ig deposits (PGNMID [2]), C3GN, (2), secondary membranous nephropathy (MN [3]), tubular basement membrane (TBM) deposits (2), and modest lupus-like GN (2). Lymphomatous infiltration was present in 8 of the 20 patients, 5 with coincident IC or C3 lesions. A total of 6 patients with available follow-up were treated for MCL, all with clinical remission of GN (2 PGNMID, 2 C3GN, and 2 MN). CONCLUSION: MCL is associated with diverse monoclonal and polyclonal glomerular and extra-glomerular IC and C3 disease. For patients with active MCL and kidney dysfunction requiring biopsy, 70% had findings due or potentially due to lymphoma, including 55% with IC or C3 disease and 40% had lymphomatous kidney infiltration. IC and C3GN in the setting of active MCL was responsive to lymphoma-directed therapy.

There are few published studies examining cytomorphologic alterations in endothelial cells in human tissue. One fascinating but largely unexplored endothelial morphologic variant is large multinucleated variant endothelial cells (MVECs). To our knowledge, there are no published reports of MVECs identified in the kidney. Here, we present a case series of 4 kidney biopsies from allograft kidneys whose microvasculature contained MVECs. Electron microscopy confirmed the endothelial identity in all cases. A broad immunohistochemical panel used in 1 case was also confirmatory of an endothelial cell origin. All cases occurred in the setting of chronic, active, antibody-mediated rejection, and alternative etiologies, such as viral infections, were excluded. Two patients were positive for concurrent donor-specific antibodies, and 3 of the 4 cases occurred in second kidney allografts. We speculate that MVECs are a rare or often overlooked finding often confused for megakaryocytes and may be associated with chronic endothelial cell injury in the setting of chronic antibody-mediated rejection.

A 47-year-old woman developed severe kidney dysfunction after taking a lipid-lowering supplement, Red Yeast Rice Cholestehelp, for approximately 7 months. The patient developed sudden nausea and had an elevated serum creatinine level of 4.26 mg/dL. A kidney biopsy showed findings consistent with acute tubular necrosis. Kidney dysfunction improved with discontinuation of supplementation, and corticosteroid therapy. Similar kidney involvement has been reported, raising concerns regarding supplements in Japan. An investigation of the nephrotoxic ingredients in the same product batches is currently underway. This report underscores the need for public awareness and warnings of health risk concerns associated with unregulated supplements. [ABSTRACT FROM AUTHOR]

BackgroundThe goal of the Artificial Intelligence in Renal Scarring (AIRS) study is to develop machine learning tools for noninvasive quantification of kidney fibrosis from imaging scans.MethodsWe conducted a retrospective analysis of patients who had one or more abdominal computed tomography (CT) scans within 6 months of a kidney biopsy. The final cohort encompassed 152 CT scans from 92 patients, which included images of 300 native kidneys and 76 transplant kidneys. Two different convolutional neural networks (slice-level and voxel-level classifiers) were tested to differentiate severe versus mild/moderate kidney fibrosis (≥50% versus

Kidney failure is common in patients with Coronavirus Disease-19 (COVID-19), resulting in increased morbidity and mortality. In an international collaboration, 284 kidney biopsies were evaluated to improve understanding of kidney disease in COVID-19. Diagnoses were compared to five years of 63,575 native biopsies prior to the pandemic and 13,955 allograft biopsies to identify diseases that have increased in patients with COVID-19. Genotyping for APOL1 G1 and G2 alleles was performed in 107 African American and Hispanic patients. Immunohistochemistry for SARS-CoV-2 was utilized to assess direct viral infection in 273 cases along with clinical information at the time of biopsy. The leading indication for native biopsy was acute kidney injury (45.4%), followed by proteinuria with or without concurrent acute kidney injury (42.6%). There were more African American patients (44.6%) than patients of other ethnicities. The most common diagnosis in native biopsies was collapsing glomerulopathy (25.8%), which was associated with high-risk APOL1 genotypes in 91.7% of cases. Compared to the five-year biopsy database, the frequency of myoglobin cast nephropathy and proliferative glomerulonephritis with monoclonal IgG deposits was also increased in patients with COVID-19 (3.3% and 1.7%, respectively), while there was a reduced frequency of chronic conditions (including diabetes mellitus, IgA nephropathy, and arterionephrosclerosis) as the primary diagnosis. In transplants, the leading indication was acute kidney injury (86.4%), for which rejection was the predominant diagnosis (61.4%). Direct SARS-CoV-2 viral infection was not identified. Thus, our multi-center large case series identified kidney diseases that disproportionately affect patients with COVID-19 and demonstrated a high frequency of APOL1 high-risk genotypes within this group, with no evidence of direct viral infection within the kidney.