Primary Glomerulonephritis Research Articles

The transcription factor HMGB2 indirectly regulates APRIL expression and Gd-IgA1 production in patients with IgA nephropathy

Background IgA nephropathy (IgAN) is the most common primary glomerulonephritis worldwide. Proliferation-inducing ligand (APRIL) was identified as an important cause of glycosylation deficiency of IgA1 (Gd-IgA1), which can ‘trigger’ IgAN. Our previous study indicated that high migration group protein B2 (HMGB2) in peripheral blood mononuclear cells from patients with IgAN was associated with disease severity, but the underlying mechanism remains unclear. Materials and methods The location of HMGB2 was identified by immunofluorescence. qRT-PCR and Western blotting were used to measure HMGB2, HMGA1, and APRIL expression. Gd-IgA1 levels were detected by enzyme-linked immunosorbent assay (ELISA). In addition, we used DNA pull-down, protein profiling, and transcription factor prediction software to identify proteins bound to the promoter region of the APRIL gene. RNA interference and coimmunoprecipitation (Co-IP) were used to verify the relationships among HMGB2, high mobility group AT-hook protein 1 (HMGA1), and APRIL. Results HMGB2 expression was greater in IgAN patients than in HCs and was positively associated with APRIL expression in B cells. DNA pull-down and protein profiling revealed that HMGB2 and HMGA1 bound to the promoter region of the APRIL gene. The expression levels of HMGA1, APRIL, and Gd-IgA1 were downregulated after HMGB2 knockdown. Co-IP indicated that HMGB2 binds to HMGA1. The Gd-IgA1 concentration in the supernatant was reduced after HMGA1 knockdown. HMGA1 binding sites were predicted in the promoter region of the APRIL gene. Conclusion HMGB2 expression is greater in IgAN patients than in healthy controls; it promotes APRIL expression by interacting with HMGA1, thereby inducing Gd-IgA1 overexpression and leading to IgAN.

Efficacy and safety of biologic agents for IgA nephropathy: A protocol for systematic review and meta-analysis.

IgA nephropathy (IgAN) is the most prevalent primary glomerulonephritis worldwide and a leading cause of chronic kidney failure. There are currently no definitive therapeutic regimens to treat or prevent the progression of IgAN. However, biologic agents offer novel therapeutic approaches that target immunological mechanisms to slow or halt disease progression. The objective of this study is to evaluate the efficacy and safety of biologic agents in patients with IgA nephropathy. We will systematically search PubMed, EMbase, Web of Science, Cochrane Library, and www.clinicaltrials.gov for randomized controlled trials of biologic agents for the treatment of IgA nephropathy. The search period will span from the establishment of each database until October 2023. The quality assessment of included studies will be performed individually using the revised Cochrane risk-of-bias tool for randomized trials (RoB 2), and meta-analysis will be conducted using Revman 5.4.1 software. The results of this study will provide evidence-based medical evidence for the clinical application of biologic agents in patients with IgA nephropathy. CRD42023400450.

Clinical and histopathological characteristics of primary focal segmental glomerulosclerosis in Turkish adults

The data regarding primary FSGS (pFSGS) from different parts of the world differ. While the prevalence of pFSGS has been increasing in Western countries like the USA, it follows an inconsistent trend in Europe and Asia and a decreasing trend in Far Eastern countries such as China in the last two decades. There are undetermined factors to explain those national and geographic discrepancies. Herein, we aimed to reveal the current prevalence with clinical and histopathological characteristics of pFSGS in Turkish adults. This study includes the biopsy-proven pFSGS patients data recorded between 2009 and 2019, obtained from the national multicenter primary glomerulonephritis registry system of the Turkish Society of Nephrology Glomerular Diseases (TSN-GOLD) database. 850 of the 3875 primer glomerulonephritis patients(21.9%) have pFSGS. The mean age is 40.5 ± 14.2 and 435 (51.2%) of patients are male. Nephrotic syndrome is the most common biopsy indication (59.2%). 32.6% of patients have hematuria, 15.2% have leukocyturia and 7.8% have both. Serum creatinine, albumin, and proteinuria are 1.0 mg/dL (IQR = 0.7–1.4) mg/dl, 3.4 ± 0.9 g/dl, 3400 mg/day(IQR, 1774–5740), respectively. Females have lower mean arterial pressure (− 2.2 mmHg), higher eGFR (+ 10.0 mL/min/1.73 m2), and BMI (+ 1.6 kg/m2) than males. Thickened basal membrane(76.6%) and mesangial proliferation (53.5%) on light microscopy are the major findings after segmental sclerosis. IgM (32.7%) and C3 (32.9%) depositions are the most common findings on immunofluorescence microscopy. IgM positivity is related to lower eGFR, serum albumin, and higher proteinuria. The prevalence of pFSGS is stable although slightly increasing in Turkish adults. The characteristics of the patients are similar to those seen in Western countries.

Sparsentan, a Dual Endothelin Type A and Angiotensin II Subtype 1 Receptor Antagonist for the Treatment of Immunoglobulin A Nephropathy: Latest Trial Results, Pharmacokinetic Considerations, and Binding Profile

Immunoglobulin A nephropathy (IgAN) is one of the most common forms of primary glomerulonephritis. In some patients, it can progress rapidly, leading to proteinuria, kidney failure, and death. Standard of care is traditionally with an angiotensin converting enzyme inhibitor (ACEi), or an angiotensin II (Ang II) receptor blocker (ARB). More recently, drugs targeting both endothelin 1 (ET-1) and Ang II receptors have been developed, as overactivation of such is implicated in IgAN. Sparsentan is a dual ET Type A (ETAR) and Ang II subtype 1 receptor (AT1R) antagonist. The PROTECT study compared sparsentan with the ARB irbesartan, in patients with IgAN and with proteinuria of ≥1 g/day despite stable dose of ACEi/ARB for ≥90 days. Data presented at the 2023 American Society of Nephrology (ASN) Kidney Week showed that use of sparsentan led to sustained (>110 weeks) decreases in proteinuria, and a significantly greater preservation of kidney function, compared with irbesartan. The ongoing SPARTAN study is investigating the use of sparsentan in recently diagnosed, treatment-naïve patients with IgAN. Preliminary data in 12 patients showed rapid and sustained proteinuria reductions, with little change from baseline in estimated glomerular filtration rate (eGFR), body weight, or total body water mean at Week 36. In both studies, sparsentan was generally well-tolerated with, in PROTECT, a comparable safety profile to irbesartan. Data presented at the congress also showed that sparsentan consistently occupies AT1R at levels exceeding ETAR occupancy. This balance is hypothesised to contribute to sparsentan’s limited risk of fluid retention.

Post-Transplant Glomerulonephritis: Challenges and Solutions.

Glomeruli can be damaged in several conditions after kidney transplantation, with a potential impact on the graft function and survival. Primary glomerulonephritis, a group of glomerular immunological damage that results in variable histological patterns and clinical phenotypes, can occur in kidney transplant recipients as a recurrent or de novo condition. Specific immunologic conditions associated with kidney transplantation, such as acute rejection episodes, can act as an additional trigger after transplantation, impacting the incidence of these glomerulopathies. The post-transplant GN recurrence ranges from 3% to 15%, varying according to the GN subtype and post-transplant time, mainly occurring after 3-5 years of kidney transplantation. Advances in the knowledge of glomerulonephritis pathophysiology have provided new approaches to pre-transplant risk evaluation and post-transplant monitoring. Glomeruli can be affected by several systemic viral infections, such as human immunodeficiency virus (HIV), hepatitis C virus (HCV), hepatitis B virus (HBV), severe acute respiratory syndrome coronavirus 2 (SARS-COV-2), cytomegalovirus (CMV), and BK virus. The diagnosis of these infections, as well as the identification of possible complications associated with them, are important to minimize the negative impacts of these conditions on kidney transplant recipients' outcomes.

Assessment of atherosclerosis and endothelial dysfunction risk factors in patients with primary glomerulonephritis

Resumo Introdução: Glomerulopatias são a terceira causa de doença renal crônica (DRC) com necessidade de diálise no Brasil. Distúrbio mineral e ósseo (DMO) é uma das complicações da DRC e está presente já nos estágios iniciais. A avaliação da espessura médio-intimal de carótidas (EMIC) e da vasodilatação fluxo-mediada (VFM) são maneiras não invasivas de avaliação do risco cardiovascular. Hipótese: Pacientes com glomerulopatias primárias (GP) apresentam alta prevalência de aterosclerose e disfunção endotelial, não explicada totalmente pelos fatores de risco tradicionais, mas provavelmente influenciada pela instalação precoce do DMO. Objetivo: Avaliar os principais marcadores de aterosclerose em pacientes com GP. Método: Estudo clínico, observacional, transversal e controlado. Foram incluídos portadores de GP e excluídos menores de 18 anos, gestantes, menos de três meses de seguimento e os com glomerulopatia secundária. Também foram excluídos aqueles que, no momento da coleta, apresentavam proteinúria maior que 6 gramas/24 horas e uso de prednisona em doses superiores a 0,2 mg/kg/dia. Resultados: 95 pacientes foram incluídos, 88 colheram os exames, 1 foi excluído e 23 não realizaram a ultrassonografia. Os pacientes com GP apresentaram maior EMIC média em relação ao controle (0,66 versus 0,60), p = 0,003. Após análise multivariada, mantiveram relevância estatística a idade e os valores de pressão arterial sistólica (PAS), VFM e TFG (p = 0,02) e VFM e ácido úrico sérico (p = 0,048). Discussão e conclusão: Pacientes com GP apresentaram maior risco cardiovascular, entretanto esse risco não foi explicitado pelo DMO precoce. Estudos clínicos randomizados e multicêntricos são necessários para melhor determinação dessa hipótese.

Diagnosing and Treating IgAN: Steroids, Budesonide, or Maybe Both?

IgA nephropathy (IgAN), the most common primary glomerulonephritis worldwide, is characterized by a mesangial IgA deposit and a variety of histological lesions, as described by the Oxford classification system. Despite the well-described "four-hit hypothesis", there are still plenty of less or undescribed mechanisms that participate in the disease pathogenesis, such as B-cell priming, which seems to be initiated by different antigens in the intestinal microbiota. Diagnosis of the disease is currently based on kidney biopsy findings, as the sensitivity and specificity of the many serum and urinary biomarkers described so far do not seem to have diagnostic accuracy. Therapeutic strategies consist of the initial step of non-immune medication, aiming to reduce both the intraglomerular pressure and proteinuria to below 0.5 g/day, followed by systemic corticosteroid administration in patients who remain at high risk for progressive chronic kidney disease despite the maximum non-immune treatment. The 6-month systemic corticosteroid treatment reduces proteinuria levels; however, the increased possibility of adverse events and increased relapse rate after treatment raises the need for a new therapeutic approach. Targeted-release budesonide is a therapeutic modality that aims to inhibit disease pathogenetic pathways at early stages; it has minor systemic absorption and proven beneficial effects on renal function and proteinuria. In the present systemic review, the benefits and adverse events of steroids and budesonide are described, and the possibility of combined treatment is questioned in selected cases with active histologic lesions.

IgA nephropathy: gut microbiome regulates the production of hypoglycosilated IgA1 via the TLR4 signaling pathway.

Immunoglobulin A nephropathy (IgAN) is a major cause of primary glomerulonephritis characterized by mesangial deposits of galactose-deficient IgA1 (Gd-IgA1). Toll-like receptors (TLRs), particularly TLR4, are involved in the pathogenesis of IgAN. The role of gut microbiota on IgAN patients was recently investigated. However, whether gut microbial modifications of Gd-IgA1 through TLR4 play a role in IgAN remains unclear. We recruited subjects into four groups, including 48 patients with untreated IgAN, 22 treated IgAN patients (IgANIT), 22 primary membranous nephropathy and 31 healthy controls (HCs). Fecal samples were collected to analyze changes in gut microbiome. Gd-IgA1 levels, expression of TLR4, B-cell stimulators and intestinal barrier function were evaluated in all subjects. C57BL/6 mice were treated with a broad-spectrum antibiotic cocktail to deplete the gut microbiota and then gavaged with fecal microbiota transplanted from clinical subjects of every group. Gd-IgA1 and TLR4 pathway were detected in peripheral blood mononuclear cells (PBMCs) from IgAN and HCs co-incubated with lipopolysaccharide (LPS) and TLR4 inhibitor. Compared with the other three groups, different compositions and decreased diversity demonstrated gut dysbiosis in the untreated IgAN group, especially the enrichment of Escherichia-Shigella. Elevated Gd-IgA1 levels were found in untreated IgAN patients and correlated with gut dysbiosis, TLR4, B-cell stimulators, indexes of intestinal barrier damage and proinflammatory cytokines. In vivo, mice colonized with gut microbiota from IgAN and IgANIT patients mimicked the IgAN phenotype with the activation of TLR4/MyD88/nuclear factor-κB pathway and B-cell stimulators in the intestine, and had with enhanced proinflammatory cytokines. In vitro, LPS activated TLR4/MyD88/NF-κB pathway, B-cell stimulators and proinflammatory cytokines in PBMCs of IgAN patients. This process may induce the overproduction of Gd-IgA1, which was inhibited by TLR4 inhibitors. Our results illustrated that the gut-kidney axis is involved in the pathogenesis of IgAN. Gut dysbiosis could stimulate the overproduction of Gd-IgA1 via TLR4 signaling pathway production and B-cell stimulators.

Identifying functional subtypes of IgA nephropathy based on three machine learning algorithms and WGCNA

BackgroundIgA nephropathy (IgAN) is one of the most common primary glomerulonephritis, which is a significant cause of renal failure. At present, the classification of IgAN is often limited to pathology, and its molecular mechanism has not been established. Therefore we aim to identify subtypes of IgAN at the molecular level and explore the heterogeneity of subtypes in terms of immune cell infiltration, functional level.MethodsTwo microarray datasets (GSE116626 and GSE115857) were downloaded from GEO. Differential expression genes (DEGs) for IgAN were screened with limma. Three unsupervised clustering algorithms (hclust, PAM, and ConsensusClusterPlus) were combined to develop a single-sample subtype random forest classifier (SSRC). Functional subtypes of IgAN were defined based on functional analysis and current IgAN findings. Then the correlation between IgAN subtypes and clinical features such as eGFR and proteinuria was evaluated by using Pearson method. Subsequently, subtype heterogeneity was verified by subtype-specific modules identification based on weighted gene co-expression network analysis(WGCNA) and immune cell infiltration analysis based on CIBERSORT algorithm.ResultsWe identified 102 DEGs as marker genes for IgAN and three functional subtypes namely: viral-hormonal, bacterial-immune and mixed type. We screened seventeen genes specific to viral hormonal type (ATF3, JUN and FOS etc.), and seven genes specific to bacterial immune type (LIF, C19orf51 and SLPI etc.). The subtype-specific genes showed significantly high correlation with proteinuria and eGFR. The WGCNA modules were in keeping with functions of the IgAN subtypes where the MEcyan module was specific to the viral-hormonal type and the MElightgreen module was specific to the bacterial-immune type. The results of immune cell infiltration revealed subtype-specific cell heterogeneity which included significant differences in T follicular helper cells, resting NK cells between viral-hormone type and control group; significant differences in eosinophils, monocytes, macrophages, mast cells and other cells between bacterial-immune type and control.ConclusionIn this study, we identified three functional subtypes of IgAN for the first time and specific expressed genes for each subtype. Then we constructed a subtype classifier and classify IgAN patients into specific subtypes, which may be benefit for the precise treatment of IgAN patients in future.

Distinct characteristics and prognosis of IgA nephropathy patients with nephrotic syndrome: a propensity score-matched cohort study.

IgA nephropathy (IgAN) is the most prevalent primary glomerulonephritis globally. While nephrotic syndrome (NS) is uncommon in IgAN, its significance remains unclear. We conducted a retrospective analysis of 170 IgAN patients, classifying them into NS (n = 85) and non-NS (n = 5) groups. Our study aims to compare their clinical characteristics, treatment responses, and prognoses. Patients were selected based on renal biopsy from 2003 to 2020. Propensity score matching ensured comparability. Clinical, pathological, and immunological data were analyzed. Composite endpoints were defined as end-stage kidney disease (ESKD) or a 30% decline in estimated glomerular filtration rate (eGFR). NS patients showed higher eGFR (74.3 ± 36.8 vs. 61.5 ± 33.6 mL/min.1.73 m2, p = 0.02), severe hematuria (35.0 (4.7,147.5) vs. 4.0 (1.8,45,0) cells/μl, p < 0.001), severe foot process effacement (p = 0.01), and lower C3 levels (1.0 ± 0.3 vs. 1.1 ± 0.2 g/L, p = 0.03). In contrast, the non-NS group had higher BMI (24.3 ± 4.0 vs. 26.8 ± 3.7 kg/m2, p < 0.001) and elevated serum uric acid levels (376 (316,417) vs. 400 (362, 501) mmol/L, p = 0.001), suggesting metabolic factors might contribute to their condition. Both groups exhibited similar MESTC scores. NS patients had higher complete remission rates (26.2% vs. 14.1%, p = 0.04). Cox regression revealed NS independently associated with a higher risk of composite endpoints (HR = 1.97, 95% CI 1.05-3.72, p = 0.04). Linear mixed models did not show significant eGFR trajectory differences. This study has established that IgAN patients with NS exhibit distinct characteristics, including active disease and increased complement activation. NS is independently associated with a poorer prognosis, emphasizing the need for targeted interventions in this subgroup.

Factor Analysis for Predicting the Structural Reorganization of the Microvasculature of the Kidneys in Patients with Glomerulonephritis and Arterial Hypertension

Objectives. Evaluation of the relationship of clinical, laboratory and morphological factors with remodeling of small-diameter renal arteries in patients with glomerulonephritis (GN) and arterial hypertension (AH). Materials and methods. The study included 105 patients (average age 37.1±1.2 years) with primary GN and hypertension who had indications for morphological investigation of kidney tissue. All patients underwent a standard examination for kidney disease, a morphological study of kidney tissue with a description of the changes that occur in the presence of glomerulonephritis, corresponding to the individual severity of the pathological process. The presence of signs of a tubulointerstitial component of damage (or tubulointerstitial component — TIC) in the form of tubulointerstitial infl ammation (TIV), fi brosis (TIF) was assessed. Vasometry of the interlobular artery (IA) was performed. The value of the intima-media complex (IMC) was considered to be a sign of IA remodeling. A sign of MA remodeling was considered to be an intima-media complex (IMC) value of more than 30.43 μm. Results. Among clinical and laboratory risk factors, an increase in systolic blood pressure has a statistically signifi cant effect on the likelihood of increasing IMC (χ2-criterion = 5.76, p = 0.016), arterial hypertension stage (χ2-criterion = 9.45, p = 0.002), blood urea level (χ2-criterion = 8.11, p = 0.004), decrease in glomerular fi ltration rate (χ2-criterion = 5.0, p = 0.025), increase in the stage of chronic kidney disease (χ2-criterion = 10.32, p = 0.001). The presence of signs of GN progression, such as an increase in erythrocyte sedimentation rate (ESR) or proteinuria, did not have a statistically significant effect on the risk of IA remodeling (p&gt;0.05). The increase in IA IMC is affected by the presence of hyalinosis of glomerular capillary loops (χ2-criterion = 7.56, p = 0.006), periglomerular hyalinosis (χ2-criterion = 6.96, p = 0.008), sclerosis of the glomerulus (χ2-criterion = 3.9, p = 0.048), increased fibrosis of tubulointerstitium (χ2-criterion = 12.16, p = 0.0005). Conclusion. In GN and AH, remodeling of small-diameter renal vessels occurs due to the influence of AH and its severity, tubulointerstitial changes in the renal tissue. New risk factors for vascular remodeling have been obtained — changes in the glomerulus. At the same time, the inflammatory and autoimmune mechanisms of GN were not associated with changes in the vascular wall. The role of hypertension is decisive in changing the structure of small-diameter kidneys.

The role of BAFF and APRIL in IgA nephropathy: pathogenic mechanisms and targeted therapies.

Immunoglobulin A nephropathy (IgAN), characterized by mesangial deposition of galactose-deficient-IgA1 (Gd-IgA1), is the most common biopsy-proven primary glomerulonephritis worldwide. Recently, an improved understanding of its underlying pathogenesis and the substantial risk of progression to kidney failure has emerged. The "four-hit hypothesis" of IgAN pathogenesis outlines a process that begins with elevated circulating levels of Gd-IgA1 that trigger autoantibody production. This results in the formation and deposition of immune complexes in the mesangium, leading to inflammation and kidney injury. Key mediators of the production of Gd-IgA1 and its corresponding autoantibodies are B-cell activating factor (BAFF), and A proliferation-inducing ligand (APRIL), each playing essential roles in the survival and maintenance of B cells and humoral immunity. Elevated serum levels of both BAFF and APRIL are observed in patients with IgAN and correlate with disease severity. This review explores the complex pathogenesis of IgAN, highlighting the pivotal roles of BAFF and APRIL in the interplay between mucosal hyper-responsiveness, B-cell activation, and the consequent overproduction of Gd-IgA1 and its autoantibodies that are key features in this disease. Finally, the potential therapeutic benefits of inhibiting BAFF and APRIL in IgAN, and a summary of recent clinical trial data, will be discussed.

Points of view in nephrology: personalized management of IgA nephropathy, beyond KDIGO.

IgA nephropathyis the most common primary glomerulonephritis worldwide, and an important cause of kidney failure, as 20-40% of patients progress to renal replacement therapy 20-30years after diagnosis. Its clinical presentation ranges from isolated microscopic hematuria to nephrotic syndrome, and even to a rapidly progressive course. Ethnicity and epigenetics play a key role in its clinical aggressiveness. Selection of patients at risk needing immunosuppressive treatment is a challenge for the nephrologist. Some active and chronic kidney lesions detected on kidney biopsy have been demonstrated to have prognostic value according to the Oxford Classification of IgA nephropathy, later validated by numerous studies. However, KDIGO 2021 guidelines still consider persistent proteinuria > 1g/24h to be the most relevant risk factor for the progression of IgA nephropathy and the only one requiring immunosuppressive treatment. KDIGO guidelines have proposed a therapeutic algorithm, but many patients present peculiar characteristics that are not addressed by the current guidelines, pointing to the need for alternative approaches. In these cases, a tailored approach to each patient should be followed in which clinical, histological, laboratory, social and ethical aspects must be considered. In this manuscript we present three cases of IgA nephropathy from different countries, highlighting many of the aspects encountered in clinical practice that illustrate an individualized approach to the treatment of these patients.

Demographic distribution analysis of different glomerular diseases in Southwest China from 2008 to 2022.

Environmental and lifestyle factors play an etiological role in the pathogenesis of different glomerular diseases. Thus, exploring the epidemic characteristics of renal disease in different nationalities and regions is important. Patients who underwent renal biopsy from October 2008 to October 2022 were included. The proportion and change tendency of glomerular diseases and the differences between the sexes and different ages and races were analyzed. There were 15,146 cases of glomerular diseases (98.5%), involving 7538 males (49.8%) and 7608 females (50.2%). The mean age was 37.0years (range 0-80years). The proportion of membranous nephropathy (MN) and diabetic nephropathy (DN) showed an increased trend. The most common primary glomerulonephritis (PGN) was IgA nephropathy (IgAN, 44.6%), followed by minimal-change disease (MCD, 24.3%) and MN (15.4%). Lupus nephritis (LN, 30%) accounted for the largest proportion of SGNs, followed by Henoch-Schonlein purpura nephritis (HSPN, 20.9%) and DN (19.8%). Compared with adults aged 18-60years old, MCD and HSPN were more common in children and MN and DN in elderly individuals, statistically significant differences. Additionally, the sex and age distribution of PGN and SGN between the Tibetan and Han populations differed significantly, whereby LN was higher in the Han population and HSPN in the Tibetan population. The distribution of glomerular diseases showed age, sex and race differences. This research will be beneficial for providing epidemiological evidence for clinical diagnosis, disease prevention and public health decision-making.

A clinical case of primary membranous glomerulonephritis with nephrotic syndrome and resistance to standard treatment

The incidence of primary membranous glomerulonephritis is 1 case per 100,000 each year (75–80 %), with a male-to-female ratio of 2 : 1. It is the cause of idiopathic nephrotic syndrome in more than 20 % of cases (over 40 % in people aged 60 and older). The problem of membranous glomerulonephritis consists in a difficult differential diagnostic search and frequent cases of resistance to treatment. Resistance to treatment may develop in 10–20 % of patients, resulting in the end-stage renal disease requiring renal replacement therapy (dialysis or kidney transplantation). Our work presents the results of clinical observation of a patient with primary membranous glomerulonephritis, nephrotic syndrome and resistance to standard treatment. This patient had a positive dynamics of clinical-laboratory-instrumental indicators and an improvement in the quality of life against the background of taking rituximab.

EPIDEMIOLOGY OF BIOPSY CONFIRMED GLOMERULONEPHRITIS IN THE REPUBLIC OF MOLDOVA: PILOT STUDY

Renal biopsy is an important tool for the diagnosis of renal pathologies and for the choice of subsequent treatment tactics. Objectives: To report the epidemiology of glomerulonephritis in the Republic of Moldova, based on histological diagnosis, and set up the premises for the creation of the National Renal Biopsy Registry. Material and methods: The histological results of percutaneous renal ultrasound-guided biopsies, performed from March 30 to February 19, 2023, were evaluated in the Timofei Moșneaga Republican Clinical Hospital, Chisinau. Demographic characteristics, paraclinical parameters (serum creatinine, serum urea, glomerular filtration rate, nictemeral protein), and histological results were analyzed. Results: The outcomes of kidney biopsies performed on fifty-three patients were examined. The prevalence of renal pathologies in young and mature adults was observed, with the average age being 46.2 years. Most of the examined patients were men (71.70%). The main indication for performing renal biopsy was nephrotic syndrome, present in 64.15% of patients. The most common types of primary glomerulonephritis were membranous glomerulonephritis (50% of cases) and membranoproliferative glomerulonephritis (20% of cases). The most frequent types of secondary glomerulonephritis were lupus nephropathy (40%) and renal amyloidosis (30%). Conclusions: This study provides the first image of the current spectrum of glomerular kidney disease in the Republic of Moldova. It also serves as the basis for the development of the National Renal Biopsy Registry, which can serve as a useful resource for health policy development

MMF as Immunosuppressive Therapy in IgA Nephropathy

Introduction: IgA Nephropathy (IgAN) is the most common cause of primary glomerulonephritis in developed countries. Treatment with ACEI/ARB has strong evidence in managing IgAN. If there is evidence of progression, immunosuppression is recommended. KDIGO guidelines do not advise Mycophenolate Mofetil’s (MMF) use in non-Chinese population currently. Methods: In this study, we reviewed immunosuppression with MMF retrospectively in IgAN patients managed at the Sussex Kidney Unit (SKU) – Brighton – United Kingdom. This was assessed using the primary measures of renal survival without requiring renal replacement therapy (RRT) and proteinuria reduction to &gt;50% of the diagnosis baseline. Twenty-five patients diagnosed with IgAN between 2011 and 2020 and had been treated with MMF were retrospectively reviewed. Data was collected until January 2023, including laboratory results, histopathology, clinic letters, and medication. For those on RRT, data was collected up until the start of RRT. Results: Twenty- Five patients were reviewed; 24 were white Caucasians, and 1 was ethnically Asian. MMF was used in all 25 patients. Three patients were treated with MMF alone and 17 in combination with steroids. Five patients had prednisolone and cyclophosphamide for three months, followed by MMF maintenance. The average treatment duration was 2 years, and the average dose was 1g BD. Five patients progressed to end-stage renal disease (ESRD), and 3 had renal transplants. Twenty patients maintained renal survival; the mean eGFR at diagnosis was 45.6+/-34.1 and, at the time of review, was 56.1+/-26.6. Of the 17 patients who presented with AKI, 5 recovered to normal renal function, 5 had end-stage renal disease (ESRD), 4 had improvements, and 3 showed a decrease in eGFR. Overall, 70.6% of AKI patients recovered to normal or CKD levels. Eighty % of the patients had renal survival without RRT during the review. Twenty patients achieved more than 50% reduction of proteinuria, with five patients having proteinuria less than 0.3 g/24 hours and nine patients less than 0.5 g/24 hours. Comparison between the proteinuria at diagnosis and at the assessment time was significant (P&lt;0.001). Conclusions: Mycophenolate mofetil effectively maintained renal survival and improved proteinuria in IgA nephropathy patients indicated for immunosuppression. The treatment was well tolerated by all patients.

Expanding options of supportive care in IgA nephropathy.

Immunoglobulin A nephropathy (IgAN) is the most common primary glomerulonephritis worldwide, with a potentially serious prognosis. At present, management of IgAN is primarily based on therapeutic lifestyle changes, and excellent blood pressure control and maximized supportive treatment with the combination of inhibition of the renin-angiotensin-aldosterone system with either inhibitors of angiotensin-converting enzyme or angiotensin II receptor blockers and inhibitors of sodium-glucose cotransporter-2, and possibly in the future also with endothelin antagonists. Supportive care currently represents the cornerstone of treatment of IgAN. Targeted-release formulation of budesonide should replace systemic corticosteroids in patients with higher proteinuria and active histological lesions. New treatment options are aimed at immunopathogenesis of IgAN including depletion or modulation of Galactose-deficient-Immunoglobulin A1-producing B cells, plasma cells, and the alternate and/or lectin pathway of complement. The exact place of monoclonal antibodies and complement inhibitors will need to be determined. This article reviews potential supportive therapies currently available for patients with IgAN.

Ethnicity and IgA nephropathy: worldwide differences in epidemiology, timing of diagnosis, clinical manifestations, management and prognosis.

Immunoglobulin A nephropathy (IgAN), the most common primary glomerulonephritis, is one of the major causes of end-stage renal disease. Significant variances in epidemiology, clinical manifestation, timing of diagnosis, management and renal prognosis of IgAN have been reported worldwide. The incidence of IgAN is the most frequent in Asia, followed by Europe, and lower in Africa. Moreover, Asian patients show more frequent acute lesions in renal histology and present poorer renal outcomes compared with Caucasians. The comorbidities also show the difference between Asians and Caucasians. Although the frequency of gross hematuria with upper respiratory tract infection is not different, comorbidities with gastrointestinal diseases are reported to be higher in Europe. Recently, genetic studies for variant ethnic patients revealed widely ranging genetic risks in each ethnicity. A genetic risk score is most elevated in Asians, intermediate in Europeans and lowest in Africans, consistent with the disease prevalence of IgAN globally. Ethnic variance might be highly affected by the difference in genetic background. However, it is also essential to mention that the different timing of diagnosis due to variant urinary screening systems and the indication for renal biopsy in different countries may also contribute to these variances. The management of IgAN also varies internationally. Currently, several novel therapies based on the pathogenesis of IgAN are being assessed and are expected to become available soon. Further understanding the ethnic variance of IgAN might help establish individualized care for this disease. Here, we review the issues of ethnic heterogeneities of IgAN.

Urinary exosomal miRNA signature of IgA nephropathy: a case–control study

IgA nephropathy is the most common primary glomerulonephritis worldwide and can progress to end-stage kidney disease (ESKD). The current “gold standard” for diagnosis is kidney biopsy, which is invasive and associated with morbidity. miRNAs are small, non-coding endogenous RNA that may serve as non-invasive biomarkers, and that are found in urinary exosomes. Thus far, there is a paucity of studies of the miRNA profile for the diagnosis of IgA nephropathy. Hence, we aimed to study the urinary exosomal miRNA signature of Indian patients with IgA nephropathy. Fifty biopsy-proven IgA nephropathy patients, 50 healthy controls and 25 patients with ESKD (IgA nephropathy) were recruited over 2 years (2020–2022). Urinary exosomes were isolated from which miRNA was extracted . Analysis of urinary exosomal miRNA was done using the digital multiplexed nCounter® human v3 miRNA Expression Assay which contains 799 unique miRNA barcodes. Candidate miRNAs were identified using Lasso regression and consensus clustering. The mean age of IgA nephropathy patients was 36.32 ± 3.067 years, mean creatinine was 2.26 ± 0.318 mg/dl and mean proteinuria was 2.69 ± 0.64 g/day. Compared to healthy controls, the majority (N = 150) of miRNAs were significantly downregulated. Five candidate miRNAs (hsa.miR.146b.3p, hsa.miR.599, hsa.miR.4532, hsa.miR.664b.5p and hsa.miR.221.5p) were able to differentiate between IgA nephropathy cases and controls (AUC > 0.90); the presence of all 5 was associated with 100% specificity and sensitivity for diagnosing IgA nephropathy cases. This study of Indian patients identified that there was a significant difference in the urinary exosomal miRNA profile between IgA nephropathy cases and healthy controls, suggesting that miRNAs may be valuable in the non-invasive diagnosis of IgA nephropathy.