Chronological Changes in the Histology of Infection-Related Glomerulonephritis in Renal Allograft: A Case Report.

We report the histological changes over time for a patient with infection-related glomerulonephritis (IRGN) that developed in a transplanted kidney. A 47-year-old man had undergone renal transplantation 3 years ago for end-stage kidney disease (ESKD). After several episodes of acute rejection, the patient was in a stable CKD condition. The abrupt development of severe microscopic hematuria and renal dysfunction was observed approximately 2 weeks after the onset of a phlegmon in his right leg. An allograft biopsy showed prominent glomerular endocapillary proliferation on light microscopy, granular C3 deposition on immunofluorescent microscopy, and subepithelial electron-dense deposits on electron microscopy, suggesting IRGN accompanied by moderate interstitial fibrosis and tubular atrophy (IFTA). Positive glomerular staining for nephritis-associated plasmin receptor (NAPlr) and plasmin activity, which are biomarkers of bacterial IRGN, supported the diagnosis. Although the infection was completely cured with antibiotic therapy, renal dysfunction persisted. A re-biopsy of the allograft 2 months later revealed resolution of the glomerular endocapillary proliferation and negative staining for NAPlr/plasmin activity, with worsening IFTA. We showed, for the first time, the chronological changes in infiltrating cells and histological markers of IRGN in transplanted kidneys. Glomerular changes, including NAPlr/plasmin activity staining, almost disappeared after the cessation of infection, while interstitial changes continuously progressed, contributing to ESKD progression.

Characterizing Glomerular Barrier Dysfunction with Patient-Derived Serum in Glomerulus-on-a-Chip Models: Unveiling New Insights into Glomerulonephritis.

Glomerulonephritis (GN) is characterized by podocyte injury or glomerular filtration dysfunction, which results in proteinuria and eventual loss of kidney function. Progress in studying the mechanism of GN, and developing an effective therapy, has been limited by the absence of suitable in vitro models that can closely recapitulate human physiological responses. We developed a microfluidic glomerulus-on-a-chip device that can recapitulate the physiological environment to construct a functional filtration barrier, with which we investigated biological changes in podocytes and dynamic alterations in the permeability of the glomerular filtration barrier (GFB) on a chip. We also evaluated the potential of GN-mimicking devices as a model for predicting responses to human GN. Glomerular endothelial cells and podocytes successfully formed intact monolayers on opposite sides of the membrane in our chip device. Permselectivity analysis confirmed that the chip was constituted by a functional GFB that could accurately perform differential clearance of albumin and dextran. Reduction in cell viability resulting from damage was observed in all serum-induced GN models. The expression of podocyte-specific marker WT1 was also decreased. Albumin permeability was increased in most models of serum-induced IgA nephropathy (IgAN) and membranous nephropathy (MN). However, sera from patients with minimal change disease (MCD) or lupus nephritis (LN) did not induce a loss of permeability. This glomerulus-on-a-chip system may provide a platform of glomerular cell culture for in vitro GFB in formation of a functional three-dimensional glomerular structure. Establishing a disease model of GN on a chip could accelerate our understanding of pathophysiological mechanisms of glomerulopathy.

The STING inhibitor (ISD-017) reduces glomerulonephritis in 129.B6.Fcgr2b-deficient mice.

The absence of stimulator of interferon genes (STING) in 129.B6.Fcgr2b-deficient mice rescue lupus phenotypes. The administration of a STING inhibitor (ISD017) into the young 129.B6.Fcgr2b-deficient mice prevents lupus nephritis development. This study mainly aimed to evaluate the effects of STING inhibition (ISD107) on established SLE in mice to prove that ISD017 could be a good therapeutic drug to reverse the already set-up autoimmunity and kidney impairment. Twenty-four-week-old Fcgr2b-deficient mice were treated with cyclophosphamide (25 mg/kg, intraperitoneal, once per week), ISD017 (10 mg/kg, intraperitoneal, three times per week), or control vehicle for 8 weeks, and were analyzed for phenotypes. Both ISD017 and cyclophosphamide treatment increased long-term survival and reduced the severity of glomerulonephritis in Fcgr2b-deficient mice. While cyclophosphamide reduced activated B cells (B220+GL-7+), ISD017 decreased activated T cells (CD4+CD69+) and neutrophils (Ly6c+Ly6g+) in Fcgr2b-deficient mice. In addition, ISD017 reduced IL-1ß and interferon-inducible genes. In summary, ISD017 treatment in symptomatic 129.B6.Fcgr2b-deficient mice reduced the severity of glomerulonephritis and increased long-term survival. ISD017 worked comparably to cyclophosphamide for treating lupus nephritis in 129.B6.Fcgr2b-deficient mice. ISD017 reduced activated T cells and neutrophils, while cyclophosphamide targeted activated B cells. These results suggested that STING inhibitors can potentially be a new therapeutic drug for treating lupus.

Crescentic glomerulonephritis due to linear IgA anti-glomerular basement membrane disease: report of a rare case.

Anti-glomerular basement membrane (GBM) disease is a rare and severe vasculitis that affects the glomerular and pulmonary capillaries and has an incidence of less than 2 cases per million individuals per year. Anti-GBM disease is mediated by autoantibodies against the α3 chain of type IV collagen. In the majority of cases, the autoantibodies are of the immunoglobulin G (IgG) class, with rare cases being mediated by immunoglobulin M (IgM) or immunoglobulin A (IgA); there are less than 15 IgA-mediated cases reported in the literature worldwide. The classic form of this disease manifests with rapidly progressive glomerulonephritis (RPGN), with or without pulmonary hemorrhage, and the diagnosis consists of identifying high titers of autoantibodies in the serum and/or deposited in the tissues. IgA antibodies are not identified in routine immunoassay tests, and renal biopsy with immunofluorescence is essential for diagnosis. We present a case of RPGN due to anti-GBM disease with linear IgA deposition, whose diagnosis was made exclusively by renal biopsy and with an unfavorable prognosis.

Effect of Curcuma longa extract on reproduction function in mice and testosterone production in Leydig cells.

Curcuma longa, best known for its culinary application as the main constituent of curry powder, has shown potential impact on the reproductive system. This study aimed to investigate the efficacy of Curcuma longa extract (CLE) on Kidney-Yang deficiency mice induced by hydrocortisone and the possible roles in testosterone secretion in Leydig cells. We evaluated male sexual behaviour, reproductive organ weight, testosterone levels, and histological tissue changes in hydrocortisone-induced mice. CLE effectively reversed hydrocortisone-induced Kidney-Yang deficiency syndrome by improving sexual behaviour, testis and epididymis weight, testosterone levels and reducing pathological damage. Our in vitro study further indicated that CLE stimulated testosterone production via upregulating the mRNA and protein expression of steroidogenic enzymes in Leydig cells. It significantly improved H89-inhibited protein expression of StAR and cAMP-response element-binding (CREB), as well as melatonin-suppressed StAR protein expression. The data obtained from this study suggest that CLE could alleviate Kidney-Yang deficiency symptoms and stimulate testosterone production by upregulating the steroidogenic pathway. This research identifies CLE as a potential nutraceutical option for addressing testosterone deficiency diseases.

USP25 attenuates anti-GBM nephritis in mice by negative feedback regulation of Th17 cell differentiation.

PURPOSE: This study aimed to elucidate the role of USP25 in a mouse model of anti-glomerular basement membrane glomerulonephritis (anti-GBM GN). METHODS: USP25-deficient anti-GBM GN mice were generated, and their nephritis progression was monitored. Naïve CD4+ T cells were isolated from spleen lymphocytes and stimulated to differentiate into Th1, Th2, and Th17 cells. This approach was used to investigate the impact of USP25 on CD4+ T lymphocyte differentiation in vitro. Furthermore, changes in USP25 expression were monitored during Th17 differentiation, both in vivo and in vitro. RESULTS: USP25-/- mice with anti-GBM GN exhibited accelerated renal function deterioration, increased infiltration of Th1 and Th17 cells, and elevated RORγt transcription. In vitro experiments demonstrated that USP25-/- CD4+ T lymphocytes had a higher proportion for Th17 cell differentiation and exhibited higher RORγt levels upon stimulation. Wild-type mice with anti-GBM GN showed higher USP25 levels compared to healthy mice, and a positive correlation was observed between USP25 levels and Th17 cell counts. Similar trends were observed in vitro. CONCLUSION: USP25 plays a crucial role in mitigating renal histopathological and functional damage during anti-GBM GN in mice. This protective effect is primarily attributed to USP25's ability to inhibit the differentiation of naïve CD4+ T cells into Th17 cells. The underlying mechanism may involve the downregulation of RORγt. Additionally, during increased inflammatory responses or Th17 cell differentiation, USP25 expression is activated, forming a negative feedback regulatory loop that attenuates immune activation.

Case of IgG4-related Disease with Crescentic Glomerulonephritis: An Unusual Presentation of the Disease.

IgG4-related disease (IgG4-RD) is a chronic systemic inflammatory  disease, characterized by tissue infiltration of lymphocytes and  IgG4-secreting plasma cells, presenting by fibrosis of different  tissues, which is usually responsive only to oral steroids therapy.  Kidneys are the most commonly involved organs, exhibiting renal  insufficiency, tubulointerstitial nephritis, and glomerulonephritis.  Here, we describe a patient with acute renal insufficiency who  was presented with edema, weakness, anemia and multiple  lymphadenopathies. Kidney and lymph node biopsy showed  crescentic glomerulonephritis in kidneys and lymphoplasmacytic  infiltration in lymph nodes. After a course of treatment with an  intravenous pulse of corticosteroid and cyclophosphamide, the  patient's symptoms subsided, and kidney function improved. DOI: 10.52547/ijkd.7788.

Association of neutrophil extracellular trap levels with Raynaud's phenomenon, glomerulonephritis and disease index score in SLE patients from Brazil.

Neutrophil extracellular traps (NETs) are cell-extruded DNA strands coated with neutrophils' nuclear proteins and enzymes from cytotoxic granules, produced by NETosis, a cell death pathway. They perform an important defensive role in innate immunity, but their increased production and/or inefficient degradation expose new antigens, such as DNA or citrullinated histone peptides, triggering autoimmunity. This study aimed to access possible associations between serum NETs levels with epidemiological, clinical, and serological data from a well-characterized SLE Brazilian patients' cohort. NET levels were evaluated in one hundred seventy serum samples of patients with Systemic Lupus Erythematosus (SLE) using an Immunoassay. Univariate and multivariate binary logistic regression used clinical patients' data as independent variables. Parametric and non-parametric tests compared log10 base serum NET levels transformed between patients' groups. SLE patients were also dichotomized into "High serum NET levels" and "Low serum NET levels" groups. All analyses were performed in R language 4.1.2, and p < 0.05 were considered significant. Increased susceptibility for high serum NET levels was observed in SLE patients with Raynaud's phenomenon (OR = 2.30, 95 % CI = 1.06-5.21 and p = 0.039), independently of any other risk factor. Also, SLE patients with Raynaud's phenomenon presented higher mean NET serum levels (mean = -0.13 vs. -0.51, p = 0.01). In addition, higher mean NET serum levels were associated with glomerulonephritis (mean = -0.45 vs. -0.12, p = 0.03). Ultimately, the SLEDAI index scored higher in the high NETs serum levels group (median = 2.0 vs. 0.0, p = 6 × 10-3). The formation of NETs might be implicated in Raynaud's phenomenon, glomerulonephritis, and disease index score in SLE patients. Our results highlight the importance of serum NET levels as a possible therapeutical target to modulate the clinical course of SLE.

A novel dosing approach for rituximab in glomerular diseases based on a population pharmacokinetic analysis.

OBJECTIVES: Rituximab is being increasingly prescribed for the treatment of autoimmune glomerular diseases. While it is highly effective for some diseases, the response is less predictable for others, which may be due to differing requirements in terms of the dosing according to the disease type and variations concerning exposure to the drug. METHODS: We compiled novel rituximab dosing schedules according to pharmacokinetic analysis of data gathered from rituximab treated patients in a tertiary referral nephrology centre between May 2020 and June 2023. The population-pharmacokinetic analysis was based on the rituximab dosing, the patients' characteristics, rituximab levels and anti-rituximab antibodies. RESULTS: The analysis, which was based on data from 185 patients, clearly highlighted differing rituximab dosing requirements for patients with ANCA associated vasculitis and minimal change disease compared to those with membranous nephropathy, focal-segmental glomerulosclerosis and lupus nephritis. This corresponded to the good treatment response of the first two diseases and the unreliable efficacy for the others. The model predicts the rituximab pharmacokinetics with high degree of accuracy when body weight, proteinuria, type of glomerulonephritis, treatment length and anti-rituximab antibodies formation are used as covariates. We proposed a dosing schedule with shortened dosing intervals for difficult-to-treat diagnoses with high proteinuria. CONCLUSION: In order to ensure reliable and comparable exposure of rituximab with respect to the full range of glomerular diseases, the dosing schedule should be adjusted for membranous nephropathy, focal-segmental glomerulosclerosis and lupus nephritis. This is largely, but not solely, due to the enhanced level of unselective proteinuria in these diseases.

Liver Disease-Associated Glomerulopathies.

Hepatitis B virus (HBV) and hepatitis C virus (HCV) infect a significant number of individuals globally and their extra-hepatic manifestations, including glomerular disease, are well established. Additionally, liver disease-associated IgA nephropathy is the leading cause of secondary IgA nephropathy with disease course varying from asymptomatic urinary abnormalities to progressive kidney injury. Herein we provide an updated review on the epidemiology, pathogenesis, clinical manifestations, and treatment of HBV- and HCV-related glomerulonephritis as well as IgA nephropathy in patients with liver disease. The most common HBV-related glomerulonephritis is membranous nephropathy, although membranoproliferative glomerulonephritis and podocytopathies have been described. The best described HCV-related glomerulonephritis is cryoglobulinemic glomerulonephritis occurring in about 30% of patients with mixed cryoglobulinemic vasculitis. The mainstay of treatment for HBV-GN and HCV-GN is antiviral therapy, with significant improvement in outcomes since the emergence of the direct-acting antivirals. However, cases with severe pathology and/or a more aggressive disease trajectory can be offered a course of immunosuppression, commonly anti-CD20 therapy, particularly in the case of cryoglobulinemic glomerulonephritis.

Reduction in Acute Post-Streptococcal Glomerulonephritis Incidence in Counties Manukau, New Zealand, after the COVID-19 Pandemic.

The COVID-19 pandemic has altered the epidemiology of many common childhood infections, including Group A streptococcal (GAS) disease. Acute post-streptococcal glomerulonephritis (APSGN) is a nonsuppurative complication of GAS pharyngitis and pyoderma. It remains the most common cause of pediatric acute glomerulonephritis globally. In Counties Manukau, New Zealand, APSGN rates have previously been shown to be the highest in the country, with marked ethnic and socioeconomic disparities. We performed a retrospective review of children aged 0-14 years who were discharged from Kidz First Hospital, Counties Manukau, between 2015 and 2023 and met the Strep A Vaccine Global Consortium consensus definition of APSGN. We describe a marked, sustained reduction in APSGN hospitalizations, temporally associated with the COVID-19 pandemic. This ongoing reduction in APSGN incidence is notable in light of contrasting reports of increasing incidence of rheumatic fever in New Zealand and invasive GAS disease internationally.

Podocyte-specific silencing of acid sphingomyelinase gene to abrogate hyperhomocysteinemia-induced NLRP3 inflammasome activation and glomerular inflammation.

Acid sphingomyelinase (ASM) has been reported to increase tissue ceramide and thereby mediate hyperhomocysteinemia (hHcy)-induced glomerular nucleotide-binding oligomerization domain-like receptor containing pyrin domain 3 (NLRP3) inflammasome activation, inflammation, and sclerosis. In the present study, we tested whether somatic podocyte-specific silencing of Smpd1 gene (mouse ASM gene code) attenuates hHcy-induced NLRP3 inflammasome activation and associated extracellular vesicle (EV) release in podocytes and thereby suppresses glomerular inflammatory response and injury. In vivo, somatic podocyte-specific Smpd1 gene silencing almost blocked hHcy-induced glomerular NLRP3 inflammasome activation in Podocre (podocyte-specific expression of cre recombinase) mice compared with control littermates. By nanoparticle tracking analysis (NTA), floxed Smpd1 shRNA transfection was found to abrogate hHcy-induced elevation of urinary EV excretion in Podocre mice. In addition, Smpd1 gene silencing in podocytes prevented hHcy-induced immune cell infiltration into glomeruli, proteinuria, and glomerular sclerosis in Podocre mice. Such protective effects of podocyte-specific Smpd1 gene silencing were mimicked by global knockout of Smpd1 gene in Smpd1-/- mice. On the contrary, podocyte-specific Smpd1 gene overexpression exaggerated hHcy-induced glomerular pathological changes in Smpd1trg/Podocre (podocyte-specific Smpd1 gene overexpression) mice, which were significantly attenuated by transfection of floxed Smpd1 shRNA. In cell studies, we also confirmed that Smpd1 gene knockout or silencing prevented homocysteine (Hcy)-induced elevation of EV release in the primary cultures of podocyte isolated from Smpd1-/- mice or podocytes of Podocre mice transfected with floxed Smpd1 shRNA compared with WT/WT podocytes. Smpd1 gene overexpression amplified Hcy-induced EV secretion from podocytes of Smpd1trg/Podocre mice, which was remarkably attenuated by transfection of floxed Smpd1 shRNA. Mechanistically, Hcy-induced elevation of EV release from podocytes was blocked by ASM inhibitor (amitriptyline, AMI), but not by NLRP3 inflammasome inhibitors (MCC950 and glycyrrhizin, GLY). Super-resolution microscopy also showed that ASM inhibitor, but not NLRP3 inflammasome inhibitors, prevented the inhibition of lysosome-multivesicular body interaction by Hcy in podocytes. Moreover, we found that podocyte-derived inflammatory EVs (released from podocytes treated with Hcy) induced podocyte injury, which was exaggerated by T cell coculture. Interstitial infusion of inflammatory EVs into renal cortex induced glomerular injury and immune cell infiltration. In conclusion, our findings suggest that ASM in podocytes plays a crucial role in the control of NLRP3 inflammasome activation and inflammatory EV release during hHcy and that the development of podocyte-specific ASM inhibition or Smpd1 gene silencing may be a novel therapeutic strategy for treatment of hHcy-induced glomerular disease with minimized side effect.NEW & NOTEWORTHY In the present study, we tested whether podocyte-specific silencing of Smpd1 gene attenuates hyperhomocysteinemia (hHcy)-induced nucleotide-binding oligomerization domain-like receptor containing pyrin domain 3 (NLRP3) inflammasome activation and associated inflammatory extracellular vesicle (EV) release in podocytes and thereby suppresses glomerular inflammatory response and injury. Our findings suggest that acid sphingomyelinase (ASM) in podocytes plays a crucial role in the control of NLRP3 inflammasome activation and inflammatory EV release during hHcy. Based on our findings, it is anticipated that the development of podocyte-specific ASM inhibition or Smpd1 gene silencing may be a novel therapeutic strategy for treatment of hHcy-induced glomerular disease with minimized side effects.

Clinical and pathological features of 52 patients with glomerulonephritis with dominant C3. / C3沉积为主的肾小球肾炎52ä¾‹ä¸´åºŠä¸Žç— ç†ç‰¹å¾.

OBJECTIVES: With the in-depth study of complement dysregulation, glomerulonephritis with dominant C3 has received increasing attention, with a variety of pathologic types and large differences in symptoms and prognosis between pathologic types. This study analyzes the clinical, pathological, and prognostic characteristics of different pathological types of glomerulonephritis with dominant C3, aiming to avoid misdiagnosis and missed diagnoses. METHODS: The clinical, pathological, and follow-up data of 52 patients diagnosed as glomerulonephritis with dominant C3 by renal biopsy from June 2013 to October 2022 were retrospectively analyzed. According to the clinical feature and results of pathology, 15 patients with post-infectious glomerulonephritis (PIGN) and 37 patients with of non-infectious glomerulonephritis (N-PIGN) were classified. N-PIGN subgroup analysis was performed, and 16 patients were assigned into a C3-alone-deposition group and 21 in a C3-dominant-deposition group, or 27 in a C3 glomerulopathy (C3G) group and 10 in a non-C3 nephropathy (N-C3G) group. RESULTS: The PIGN group had lower creatinine values (84.60 µmol/L vs179.62 µmol/L, P=0.001), lower complement C3 values (0.36 g/L vs0.74 g/L, P<0.001) at biopsy, and less severe pathological chronic lesions compared with the N-PIGN group. In the N-PIGN subgroup analysis, the C3-dominant-deposition group had higher creatinine values (235.30 µmol/L vs106.70 µmol/L, P=0.004) and higher 24-hour urine protein values (4 025.62 mg vs1 981.11 mg, P=0.037) than the C3-alone-deposition group. The prognosis of kidney in the PIGN group (P=0.049), the C3-alone-deposition group (P=0.017), and the C3G group (P=0.018) was better than that in the N-PIGN group, the C3-dominant-deposition group, and the N-C3G group, respectively. CONCLUSIONS: Glomerulonephritis with dominant C3 covers a variety of pathological types, and PIGN needs to be excluded before diagnosing C3G because of considerable overlap with atypical PIGN and C3G; in addition, the deposition of C1q complement under fluorescence microscope may indicate poor renal prognosis, and relevant diagnosis, treatment, and follow-up should be strengthened.

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.