Search Results (48)

Complement system inhibitors are emerging as promising therapies in nephrology, particularly for diseases where complement dysregulation is central to pathogenesis. This review summarizes the role of complement activation in kidney diseases and current evidence supporting complement-targeted treatments. As the complement system can be involved in the pathogenesis of different diseases to varying degrees, several research works have been conducted. These research efforts aim, firstly, to understand the mechanisms and role of complement cascade components in the most prevalent nephrological diseases and, secondly, to explore the potential of complement system inhibitors in these conditions and their possible clinical applications. Clinical trials demonstrate that complement inhibitors are most effective in conditions with significant complement involvement, such as C3 glomerulopathy (C3G), atypical hemolytic uremic syndrome (aHUS), and immune complex membranoproliferative glomerulonephritis (IC-MPGN). These agents show variable benefits in diseases with partial complement activation, including lupus nephritis and ANCA-associated vasculitis, while their role in disorders like diabetic nephropathy and focal–segmental glomerulosclerosis remains limited. Complement inhibition offers a targeted strategy to prevent disease progression and improve outcomes in selected nephrological disorders. Full article

There is rapidly increasing evidence of the role of complement in different forms of kidney disease and this has broadened the field to involve not only atypical hemolytic uremic syndrome (aHUS) and C3 glomerulopathy (C3G), but also a number of other glomerular diseases, mainly ANCA-associated renal vasculitis, immune-complex glomerulonephritis, membranous nephropathy, and IgA nephropathy (IgAN). In parallel, the field of therapeutic agents able to target the three complement pathways at different levels, both proximally and terminally, has grown tremendously in recent years. This has led to the approval of agents targeting complement for ANCA-associated vasculitis, IgA nephropathy, and, very recently, C3 glomerulopathy. The real-world implementation of these agents remains a challenge. This review will attempt, through the presentation of representative clinical vignettes, to provide some practical guidance for the nephrologist in how to navigate these new therapeutic opportunities, focusing on aHUS, C3G, and IgAN. Full article

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (ANCA-vasculitis) is an autoimmune disease characterized by inflammation and necrosis of small or medium vessels. In the past, the role of the complement in the pathogenesis of ANCA-vasculitis has been underestimated, due to the paucity of the complement at sites of injured glomeruli. Following evidence from animal models of the major role of the complement in pathogenesis of ANCA-vasculitis, the complement has again attracted interest. Immunohistology analysis of pauci-immune glomerulonephritis—ANCA glomerulonephritis (ANCA-GN)—reveals the presence of complement products and membrane attack complex, suggesting their involvement in the disease process. Researchers emphasize the complement classical or lectin pathway as a contributor to the development of ANCA-vasculitis. The era of targeted therapies to suspend the complement activation as a therapy for ANCA-vasculitis has arrived, and thus, the comprehension of its role is very important. This review summarizes recent insights on the important role of complement activation in the development of ANCA-vasculitis as well as the emerging therapeutic possibilities that target complement components for the treatment of this condition. Full article

Background: Anti-PAR 1 (protease-activated receptor 1) and anti-ACE 2 (angiotensin 2-converting enzyme 2) antibodies are a kind of non-HLA (human leukocyte antigens) antibodies postulated to be of significance in autoimmunological diseases and organ transplantation. Methods: We assessed anti-PAR 1 and anti-ACE 2 antibody levels in patients with membranous nephropathy n= 18, focal and segmental glomerulosclerosis (FSGS) n = 25, lupus nephritis (LN) n = 17, IgA nephropathy n = 14, mesangial proliferative (non-IgA) glomerulonephritis n = 6, c-ANCA (cytoplasmic anti-neutrophil cytoplasmic antibodies) vasculitis n = 40, p (perinuclear)-ANCA vasculitis n = 16, and compared them with a healthy control group n = 22. Next, we observed the clinical course of the patients (creatinine, total protein, and albumin) up to 2 years and correlated the results with the level of antibodies. Results: The anti-PAR 1 antibody level was lower in membranous nephropathy and FSGS compared to the control group. Anti-PAR 1 antibody levels were higher in secondary compared to primary glomerulonephritis. Both anti-PAR 1 and anti-ACE 2 antibody levels correlated positively (in focal and segmental glomerulosclerosis) or negatively (in lupus nephritis) with total protein and albumin at different time points of observation. Anti-PAR 1 and anti-ACE 2 antibody levels correlated also with creatinine level at one time point of observation in IgA nephropathy. Anti-PAR 1 and anti-ACE 2 antibodies correlated with each other in membranous nephropathy, FSGS, and p- and c-ANCA vasculitis (p < 0.05). Conclusions: The anti-PAR 1 antibody level was lower in membranous nephropathy and focal and segmental glomerulosclerosis compared to the control group. Anti-PAR 1 antibody levels tend to be higher in secondary compared to primary glomerulonephritis. Full article

Kidney transplantation is the most effective replacement therapy for kidney failure, providing the best outcomes in terms of patient survival and offering a better quality of life. However, despite the progressive improvement in kidney survival, the recurrence of original disease remains one of the most important causes of graft loss and a major challenge that requires clinical vigilance throughout the transplant’s duration. Additionally, the type and severity of recurrence affect both treatment options and graft survival. This is especially true for the recurrence of systemic diseases. In this narrative review, we will discuss the timing, frequency, severity, and treatment of post-transplant recurrence in three systemic diseases: lupus nephritis (LN), Antineutrophil Cytoplasmic Antibodies (ANCA)-associated glomerulonephritis (ANCA-GN), and Henoch–Schönlein purpura (HSP). The recurrence of lupus nephritis is less common than that of primary focal segmental glomerulosclerosis or C3 glomerulopathy. Its severity can range from mild mesangial to diffuse proliferative forms, with varying prognoses and treatment options, much like the original disease. In some patients with LN, as well as in those with ANCA-GN or HSP, the reactivation of the primary disease can affect other organs besides the kidneys, potentially leading to life-threatening conditions. These cases may require a multidisciplinary approach, making these transplants clinically more challenging. Extrarenal flare-ups often necessitate an increase in immunosuppression, which in turn raises the risk of infections. In these autoimmune diseases, the role of immunological tests in determining the timing of kidney transplants remains a topic of ongoing debate. However, elevated levels of certain immunological markers, such as anti-dsDNA antibodies, ANCA titers, or serum immunoglobulin A may indicate a reactivation of the disease, suggesting the need for more intensive patient monitoring. Full article

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a disease entity characterized by systemic vasculitis positive for ANCAs, which often leads to severe organ damage such as diffuse bronchoalveolar hemorrhage and rapidly progressive glomerulonephritis. It is known that the incidence and characteristics of AAV vary depending on region, and differences in the peak age of onset, the ratio of positive rates of MPO-ANCA to PR3-ANCA, and occurrence rates of GPA and MPA may have resulted in different approaches to clinical practice. It may also be necessary to modify therapeutic strategies according to ethnic factors. Avacopan is a therapeutic option recently recommended for the management of AAV; however, the rate of severe liver injuries associated with avacopan was reported to be relatively high in the Japanese population. In this review, we introduce current globally recognized knowledge on the diagnosis and treatment of AAV, including a comparison of patient characteristics and clinical practice between Europe and Japan obtained from the recent literature. Full article

Background: Anti-ETAR (endothelin A receptor) antibodies and anti-CXCR3 (C-X-C motif chemokine receptor 3) antibodies are types of non-HLA (human leukocyte antigens) antibodies that could have some influence on the course of glomerulonephritis. The authors aimed to study the influence of these antibodies’ levels on the course of specific glomerulonephritis types. Methods: We evaluated the anti-ETAR and anti-CXCR3 antibody levels in the serum of patients with membranous nephropathy (n = 18), focal and segmental glomerulosclerosis (FSGS) (n = 25), systemic lupus erythematosus (n = 17), IgA nephropathy (n = 14), mesangiocapillary glomerulonephritis (n = 6), anti-neutrophil cytoplasmic antibodies (c-ANCA) vasculitis (n = 40), and perinuclear anti-neutrophil cytoplasmic antibodies (p-ANCA) vasculitis (n = 16), and we compared their levels with the control group (n = 22). Next, we observed the patients’ clinical parameters (serum creatinine, albumin, total protein) for 2 years and checked the correlation of the clinical course markers with basic receptor antibody level. Results: Our results indicate lower anti-ETAR antibody levels in patients with FSGS and IgA nephropathy compared to the control group. Both types of antibodies correlated with creatinine levels after 2 years of observation in IgA nephropathy. Both types of antibodies seemed to negatively influence the total protein and albumin levels in systemic lupus erythematosus. Conclusions: This prospective observation showed that anti-ETAR and anti-CXCR 3 antibody levels are connected with the course of IgA nephropathy and lupus nephritis. Full article

Epitope spreading is a critical mechanism driving the progression of autoimmune glomerulonephritis. This phenomenon, where immune responses broaden from a single epitope to encompass additional targets, contributes to the complexity and severity of diseases such as membranous nephropathy (MN), lupus nephritis (LN), and ANCA-associated vasculitis (AAV). In MN, intramolecular spreading within the phospholipase A2 receptor correlates with a worse prognosis, while LN exemplifies both intra- and intermolecular spreading, exacerbating renal involvement. Similarly, ANCA reactivity in AAV highlights the destructive potential of epitope diversification. Understanding these immunological cascades reveals therapeutic opportunities—targeting early epitope spreading could curb disease progression. Despite promising insights, the clinical utility of epitope spreading as a prognostic tool remains debated. This review provides a complete overview of the current evidence, exploring the dual-edged nature of epitope spreading, the intricate immune mechanisms behind it, and its therapeutic implications. By elucidating these dynamics, we aim to pave the way for more precise, targeted interventions in autoimmune glomerular diseases. Full article

Stem and progenitor cells have been observed to contribute to regenerative processes in acute renal failure and chronic kidney disease. Recent research has delved into the intricate mechanisms by which stem and progenitor cells exert their influence on kidney diseases. Understanding how these cells integrate with the existing renal architecture and their response to injury could pave the way for innovative treatment strategies aimed at promoting kidney repair and regeneration. Overall, the role of stem and progenitor cells in kidney diseases is multifaceted, with their ability to contribute to tissue regeneration, immune modulation, and the maintenance of renal homeostasis. Here, we review the studies that we have available today about the involvement of stem and progenitor cells both in regenerative therapies and in the causes of renal diseases, as well as in natural healing mechanisms, taking into account the main kidney disorders, such as IgA nephropathy, lupus nephritis, diabetic nephropathy, C3 glomerulopathy, focal segmental glomerulosclerosis, idiopathic membranous nephropathy, anti-glomerular basement membrane glomerulonephritis, and ANCA-associated crescentic glomerulonephritis. Moreover, based on the comprehensive data available in the framework of the specific kidney diseases on stem cells and renal progenitors, we hypothesize a possible role of adult renal progenitors in exacerbating or recovering the illness. Full article

Background: There is still no consensus about the coronavirus disease 2019 (COVID-19) vaccine-associated glomerular disease (CVAGD). Given the large number of vaccinations administered and the variations in glomerulopathy observed across different countries and regional environments, CVAGD remains an important area of concern. Aim of study: We aimed to elucidate the findings of CVAGD within a Taiwanese cohort using biopsy data. Additionally, we endeavored to clarify the presentation of CVAGD. Methods: We collected data from patients who underwent renal biopsy from June 2021 to October 2022 at Taichung Veterans General Hospital. Two independent nephrologists meticulously reviewed the charts to exclude cases unrelated to vaccination. Results: Initially, a total of 286 patients underwent renal biopsy at our institute. Ultimately, we identified 14 patients with highly suspected CVAGD. All 14 patients exhibited proteinuria and hematuria. The urinary protein-to-creatinine ratio was elevated (median of 2012.1 mg/g; interquartile range (IQR) 25%–IQR 75%: 941.85–3884.1 mg/g) with a median serum creatinine level of 1.71 mg/dL (0.79–5.35). The majority of CVAGD cases were diagnosed as immunoglobulin A (IgA) nephropathy (n = 5, 35.7%), followed by antineutrophil cytoplasmic antibody (ANCA)-related rapidly progressive glomerulonephritis (RPGN) (n = 4, 28.6%). There were only three cases of minimal change disease each: one case of focal segmental glomerulosclerosis, one of membranous glomerulonephritis, and one of lupus nephritis. The culprit of COVID-19 vaccinations was 35.7% (n = 5) of Oxford-AstraZeneca (ChAdOx1-S), 42.9% (n = 6) of Moderna, and 21.4% (n = 3) of BNT162b2. Most patients experienced improvements in renal function. Only two cases of P-ANCA RPGN and one case of IgA nephropathy did not recover. Eighty percent of IgA nephropathy cases had favorable outcomes, but none of the patients with P-ANCA RPGN achieved full recovery. Conclusions: IgA nephropathy and ANCA-related RPGN were the most common CVAGD, and all types of COVID-19 vaccines posed a risk for CVAGD. However, further studies are required to confirm causality. Full article

The gut microbiota and short chain fatty acids (SCFA) have been associated with immune regulation and autoimmune diseases. Autoimmune kidney diseases arise from a loss of tolerance to antigens, often with unclear triggers. In this review, we explore the role of the gut microbiome and how disease, diet, and therapy can alter the gut microbiota consortium. Perturbations in the gut microbiota may systemically induce the translocation of microbiota-derived inflammatory molecules such as liposaccharide (LPS) and other toxins by penetrating the gut epithelial barrier. Once in the blood stream, these pro-inflammatory mediators activate immune cells, which release pro-inflammatory molecules, many of which are antigens in autoimmune diseases. The ratio of gut bacteria Bacteroidetes/Firmicutes is associated with worse outcomes in multiple autoimmune kidney diseases including lupus nephritis, MPO-ANCA vasculitis, and Goodpasture’s syndrome. Therapies that enhance SCFA-producing bacteria in the gut have powerful therapeutic potential. Dietary fiber is fermented by gut bacteria which in turn release SCFAs that protect the gut barrier, as well as modulating immune responses towards a tolerogenic anti-inflammatory state. Herein, we describe where the current field of research is and the strategies to harness the gut microbiome as potential therapy. Full article

ANCA-associated vasculitides (AAV) are rare, autoimmune conditions associated with end-stage kidney disease (ESKD) and mortality. Data have predominately been from White populations of European ancestry although geographical differences are well documented. Few studies have looked at the incidence, phenotype and clinical outcomes of ethnic minority patients, in particular Indo-Asian populations. A two-center, retrospective cohort study was conducted of patients with ANCA-associated glomerulonephritis (AAGN), self-identifying as Indo-Asian in the North West, UK between 2009 and 2023. A control group of White patients was identified from the same databases and recruited consecutively in relation to the original cohort of Indo-Asian patients. A total of 66 patients were included, 24 patients of Indo-Asian ethnicity and a control cohort of 42 patients of White ethnicity. Indo-Asian patients had a lower median age at diagnosis (53.0 vs. 57.5 years, p = 0.15) and there was an increased prevalence of diabetes mellitus (33.3% vs. 4.8%, p = 0.002) and a higher incidence of previous TB exposure (12.5% vs. 0%, p = 0.019). Outcomes including relapse, ESKD and mortality were similar. We demonstrated an increased crude incidence of AAGN in Indo-Asian patients in the UK compared to similar epidemiological studies. Consideration needs to be given to epidemiological and genetic research, achieved by collaboration and broader recruitment in clinical trials. Full article

Immune mechanisms play an important role in the pathogenesis of glomerulonephritis (GN), with autoimmunity being the main underlying pathogenetic process of both primary and secondary GN. We present three autoimmune diseases mediated by different autoimmune mechanisms: glomerulonephritis in vasculitis mediated by anti-neutrophil cytoplasmic antibodies (ANCAs), glomerulonephritis mediated by anti-glomerular basement membrane antibodies (anti-GBM antibodies), and immune complex-mediated glomerulonephritis. Some of these diseases represent a common clinical and histopathologic scenario, namely rapidly progressive crescentic glomerulonephritis. This is a severe illness requiring complex therapy, with the main role being played by therapy aimed at targeting immune mechanisms. In the absence of immune therapy, the crescents, the characteristic histopathologic lesions of this common presentation, progress toward fibrosis, which is accompanied by end-stage renal disease (ESRD). The fact that three diseases mediated by different immunopathologic mechanisms have a common clinical and histopathologic picture reveals the complexity of the relationship between immunopathologic mechanisms and their clinical expression. Whereas most glomerular diseases progress by a slow process of sclerosis and fibrosis, the glomerular diseases accompanied by glomerular crescent formation can progress, if untreated, in a couple of months into whole-nephron glomerulosclerosis and fibrosis. The outcome of different immune processes in a common clinical and histopathologic phenotype reveals the complexity of the relationship of the kidney with the immune system. The aim of this review is to present different immune processes that lead to a common clinical and histopathologic phenotype, such as rapidly progressive crescentic glomerulonephritis. Full article

Levamisole is an anti-helminthic drug with immunomodulatory properties that is added to cocaine to increase its potency and weight. Levamisole-adulterated cocaine (LAC) may cause an antineutrophil cytoplasmic antibody (ANCA)-associated systemic small vessel vasculitis (AAV). We aimed to characterize the phenotype of persons developing pulmonary-renal syndrome (PRS) in LAC-induced AAV and summarize its treatment and outcomes. Pubmed and Web of Science were searched (until September 2022). Reports that described co-existing diffuse alveolar hemorrhage and glomerulonephritis in an adult (age ≥ 18) with confirmed or suspected LAC exposure were included. Reports, demographics, clinical and serologic features, treatment and outcome characteristics were extracted. Of the 280 records identified, eight met the inclusion criteria, including eight unique cases. Persons were aged 22–58 years, and 50% were women. Cutaneous involvement occurred in only half of the cases. Other associated vasculitis findings and serologies were heterogeneous. All patients received immunosuppression with steroids, with cyclophosphamide and rituximab commonly added. We concluded that PRS could occur from LAC-induced AAV. Distinguishing LAC-induced AAV from primary AAV is challenging as clinical and serologic presentations overlap. Asking about cocaine use is requisite in persons presenting with PRS to guide diagnosis and appropriately counsel on cocaine cessation in conjunction with immunosuppression as treatment. Full article

Vaccines against SARS-CoV-2 (COVID-19) proved beneficial for COVID-19 disease attenuation and preventing virus spreading. Cumulative reports of the rarity of antineutrophil cytoplasmic autoantibodies (ANCA)-associated vasculitis (AAV) raise concerns about its relationship with COVID-19 vaccination. Several case reports described ANCA-associated pauci-immune glomerulonephritis (ANCA-GN) following COVID-19 vaccination with some uniqueness. We systematically reviewed COVID-19 vaccine-induced ANCA-GN from PubMed, SCOPUS, and Cochrane library databases until 1 January 2023 according to PRISMA guidelines and presented our three cases. Twenty-six cases from 25 articles, including our 3 cases, were analyzed. Most cases were diagnosed following the second dose of the COVID-19 vaccine (59%) with a median (IQR) interval onset of 14 (16) days. The highest prevalence was related to the mRNA-type vaccine. Anti-myeloperoxidase (MPO) ANCA was far more common than the other ANCAs, with various positive autoantibodies. Fourteen cases (out of 29 cases, 48%) had extra-kidney AAV manifestation. Although severe kidney injury was observed in 10/29 (34%), remission was achieved in 89% (25/28) with no death. The mechanisms of the vaccine-inducing ANCA-GN were postulated here. Since ANCA-GN after the COVID-19 vaccine was rare, the benefit of the COVID-19 vaccine could outweigh the risk of ANCA-GN side effects in the pandemic era. Full article