"C3 glomerulonephritis"

C3 glomerulopathy (C3G) is a rare disease resulting from dysregulation of the alternative pathway of complement. C3G includes C3 glomerulonephritis (C3GN) and dense deposit disease (DDD), both of which are characterized by bright glomerular C3 staining on immunofluorescence studies. However, on electron microscopy (EM), DDD is characterized by dense osmiophilic mesangial and intramembranous deposits along the glomerular basement membranes (GBM), while the deposits of C3GN are not dense. Why the deposits appear dense in DDD and not in C3GN is not known...

Objectives. Atypical hemolytic uremic syndrome (aHUS) is a rare complement-mediated kidney disease with genetic predisposition and represents up to 10% of pediatric hemolytic uremic syndrome (HUS) cases. Few studies have evaluated aHUS in Latin American population. We studied a Colombian pediatric cohort to delineate disease presentation and outcomes. Methods. A multicenter cohort of 27 Colombian children with aHUS were included. Patients were grouped by age at onset. Clinical features were compared using analysis of variance (ANOVA) and Fisher exact tests...

C3 glomerulopathy is a rare and complex renal disease driven by complement dysregulation, with variable presentation and pathophysiology. We report the case of a middle-aged male patient presenting with nephritic and nephrotic syndromes and low serum C3, whose biopsy established the diagnosis of C3 glomerulonephritis. He was found to be homozygous for the complement factor H-related protein (CFHR)3-CFHR1 deletion, which has been associated with the development of anti-factor H autoantibodies. However, the lack of consistent and accessible nephritic factor assays prevented full clarification of the mechanisms involved in the disease...

Syphilis is a curable sexually transmitted infection caused by the spirochete Treponema pallidum . Its clinical manifestations are variable as it has a remarkable aptitude to imitate a spectrum of clinical pictures. This phenomenon has bestowed upon it the epithet "the great imitator" within the medical literature. The escalating global prevalence of syphilis cases underscores the importance of shedding light on its rare manifestations. Syphilitic nephropathy is an uncommon manifestation of secondary syphilis...

AIM: To compare changes in the complement system in C3-glomerulopathy (C3-GP) and atypical hemolytic uremic syndrome (aHUS) after the relief of an acute episode of thrombotic microangiopathy. MATERIALS AND METHODS: The study included 8 patients diagnosed with C3-GP and 8 with aHUS in remission. The blood levels of the complement system components were determined: C3, C4, C3a, C5a, factor H (CFH), factor B (CFB), membrane-attacking complex (MAC), antibodies to C3b (anti-C3b-AT), the level of hemolytic activity (CH50), the content of factor D (CFD) in the urine...

Dense deposit disease (DDD) and C3 glomerulonephritis (C3GN) are types of membranoproliferative glomerulonephritis classified as C3 glomerulopathies. These conditions are characterized by an increased number of intraglomerular cells and diffuse thickening of the glomerular capillary walls, along with the deposition of C3 and minimal or absent immunoglobulin deposits. The underlying cause of both DDD and C3Gn is an abnormal activation of the alternative complement pathway, which can result from acquired or genetic alteration...

BACKGROUND: C3 glomerulopathy (C3G) is a complement-mediated disease. Although genetic studies are not required for diagnosis, they are valuable for treatment planning and prognosis prediction. The aim of this study is to investigate the clinical phenotypes, kidney survival, and response to mycophenolate mofetil (MMF) treatment in pediatric C3G patients with and without mutations in complement-related genes. METHODS: Sixty pediatric C3G patients were included, divided into two groups based on complement-related gene mutations...

Glomerular diseases are common causes of chronic kidney disease in childhood, adolescence, and adulthood. The epidemiology of glomerular diseases differs between different age groups, with minimal change disease being the leading cause of nephrotic syndrome in childhood, while membranous nephropathy and focal segmental glomerulosclerosis are more common in adulthood. IgA vasculitis is also more common in childhood. Moreover, there is a difference in disease severity with more children presenting with a relapsing form of nephrotic syndrome and a more acute presentation of antineutrophil cytoplasmic antibody-associated vasculitis and concomitant glomerulonephritis, as highlighted by the higher percentage of cellular crescents on kidney biopsy specimens in comparison with older patients...

Post-infectious glomerulonephritis (PIGN) is an immune complex mediated glomerular injury occurring because of an infection, most commonly with group A beta-hemolytic streptococcus in children. C3 glomerulopathy (C3G) is a distinct clinicopathological entity occurring secondary to dysregulation of alternate complement pathway encompassing both C3 glomerulonephritis (C3GN) and dense deposit disease (DDD). While most patients with PIGN attain complete remission with normalized complement levels by 6-8 weeks after presentation, patients with C3G continue to have hypocomplementemia with high rates of progressive kidney disease...

BACKGROUND: Postinfectious glomerulonephritis with C3-dominant glomerular deposition (C3-PIGN) involves C3-dominant glomerular deposition without immunoglobulin. Atypical C3-PIGN involves persistent hypocomplementemia. We investigated the clinical features and explored complement-related gene mutations in atypical PIGN patients. METHODS: We enrolled atypical C3-PIGN patients and collected data regarding the clinical presentation and pathological characteristics and follow-up data...

This study elucidated the etiology of C3 glomerulonephritis (C3GN) and non-C3GN with primary membranoproliferative glomerulonephritis (MPGN) using transmission electron microscopy (TEM) and periodic acid-methenamine silver stain (PAM-EM). Thirty-one primary MPGN cases were analyzed by TEM and PAM-EM to distinguish among MPGN I, MPGN II, MPGN III Burkholder subtype (MPGN IIIB), and Anders and Strife subtype (MPGN IIIA/S). Each case was also classified into C3GN or non-C3GN according to the standard C3GN definition using immunostaining...

Complement 3 glomerulopathy (C3G) is an ultra-rare, progressive kidney disease resulting from dysregulation of the alternative complement pathway. Clinical presentation of C3G is heterogeneous and definitive diagnosis relies on kidney biopsy and immunofluorescence staining. The term C3G encompasses two subgroups, dense deposit disease and C3 glomerulonephritis, distinguished via electron microscopy. In this podcast article, the authors discuss the challenges associated with C3G diagnosis and the central role of kidney biopsy...

Membranoproliferative glomerulonephritis (MPGN) represents a heterogeneous group of diseases. The common feature of a membranoproliferative lesion pattern in the kidney biopsy can either be idiopathic/primary or-much more frequently-have a secondary cause. The historical classification into MPGN types I to III has largely been abandoned and replaced in recent years by a pathogenesis-oriented classification. A MPGN with C1q, C3 and/or C4 deposits on light microscopy is referred to as immune complex GN (IC-GN), while a MPGN with dominant C3 deposits is referred to as C3 glomerulopathy (C3G)...

Monoclonal gammopathy of undetermined significance (MGUS) is usually an asymptomatic pre-malignant condition caused by the proliferation of clonal plasma cells. Often considered a benign condition, it has the potential to progress to malignant plasma cell or lymphoproliferative disorders. Moreover, MGUS can rarely cause glomerular disease by activating the alternative complement pathway resulting in immunoglobulin-negative C3-positive glomerulonephritis called C3 glomerulopathy. Because of its rarity, the diagnosis might not be considered by the treating physicians, leading to delayed diagnosis or misdiagnosis...

C3 glomerulonephritis (C3GN) is a rare cause of end-stage kidney disease and frequently recurrent in allografts following kidney transplantation (KT). Herein, we describe the case of a kidney transplant recipient who developed recurrent C3GN along with BK-virus-associated nephropathy (BKVAN) following KT. A 33-year-old man diagnosed with membranoproliferative glomerulonephritis 17 years ago underwent preemptive KT with a donor kidney from his aunt. Proteinuria gradually increased after 3 months following KT, and graft biopsy was performed 30 months after KT...

Poststreptococcal acute kidney glomerulonephritis (PSAGN) has been seen in adults in recent years, especially in patients with type 2 diabetes mellitus, and the renal prognosis has not always been good. There have been cases of PSAGN in which complete remission was not achieved and hematuria and proteinuria persisted, leading to end-stage renal disease. Previous reports showed that the patients subjected to PSAGN have an underlying defect in regulating the alternative pathway of complement, and they identified that antibodies to the C3 convertase, C3 nephritic factors (C3NeF), are involved...

We performed a kidney biopsy in a 36-year-old man to evaluate microscopic hematuria and proteinuria. Light microscopy showed increased mesangial matrix and partial swelling of the glomerular basement membrane (GBM), and immunofluorescence showed positive staining only for C3. Immunoelectron microscopy showed that gold particle-labeled C3 was localized in the electron-dense and moderately electron-dense deposits shown by electron microscopy in the mesangium, the thickened GBM near the paramesangium, and the thickened distal portion of the GBM but was not localized in the non-thickened GBM...

BACKGROUND The incidence of glomerular disease recurrence in kidney transplant patients varies according to type of glomerulopathy; therefore, it is important to know the primary chronic kidney disease etiology. C3 glomerulopathy (C3G) is characterized by deposits of C3 in immunofluorescence and its pathogeny is based on the dysregulation of the alternative complement pathway. C3G has a high recurrence rate and, given its low prevalence, only case series have been published. A higher rate of recurrence and a more aggressive course have been described in association with monoclonal gammopathy (MG)...

BACKGROUND: C3 glomerulonephritis (C3GN) is a subtype of C3 glomerulopathy (C3G), characterized by dysregulation of the alternative pathway of complement and by dominant C3 by immunofluorescence on the kidney biopsy. There is no approved treatment for patients with C3G. Immunosuppressive drugs as well as biologics have been used with limited success. In recent decades, substantial advances in the understanding of the complement system have led to the development of new complement inhibitors...

BACKGROUND: Immune checkpoint inhibitors (ICIs) are increasingly being used in the treatment of several cancers. Pembrolizumab is an anti-programmed cell death-1 (anti-PD-1) monoclonal antibody that is approved for the treatment of metastatic non-small cell lung cancer (NSCLC). Pembrolizumab-associated renal toxicity is relatively rare, even in pembrolizumab-associated glomerulonephritis. In this study, we report a rare case of pembrolizumab-induced C3 glomerulonephritis (C3GN) and RBC cast nephropathy...