Search Results (38)

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

Background/Objectives: Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis is a rare autoimmune disease marked by small-vessel inflammation. Pulmonary and renal manifestations are believed to critically influence prognosis, but detailed regional data are lacking. This study aimed to determine the prevalence and prognostic impact of pulmonary and renal involvement in AAV patients in the Thrace region of Türkiye. Methods: A retrospective cohort study was conducted on 78 biopsy-proven AAV patients followed between 2018 and 2025. Demographic, clinical, laboratory, and outcome data were analysed. Logistic regression identified predictors of relapse and mortality. Results: The cohort included 44 granulomatosis with polyangiitis, 30 microscopic polyangiitis, and 4 eosinophilic granulomatosis with polyangiitis patients; 40 were pr3-ANCA positive and 33 MPO-ANCA positive. Pulmonary involvement was observed in 71.8% and renal involvement in 74.4%, and overall mortality was 20.5%. All deaths occurred in patients with pulmonary involvement (28.6% vs. 0%, p = 0.048). Relapse was higher in those with pulmonary (17.9% vs. 4.5%, p = 0.048) and renal (15.5% vs. 5%, p = 0.056) involvement. Multivariate analysis showed that pulmonary involvement (OR 3.82, p = 0.002), renal involvement (OR 4.73, p = 0.013), and rituximab treatment (OR 10.79, p = 0.049) predicted relapse; elevated CRP (OR 1.01, p = 0.003), creatinine (OR 1.42, p = 0.028), hypoalbuminaemia (OR 0.24, p = 0.046), renal (OR 2.86, p = 0.031), and pulmonary (OR 3.21, p = 0.003) involvement predicted mortality. Conclusions: Pulmonary and renal involvement are highly prevalent and represent the strongest predictors of relapse and mortality in AAV patients in this regional cohort. Recognising these risks is essential to guide early interventions and improve patient outcomes. Full article

Background/Objectives: The overlap syndrome of primary Sjögren syndrome (pSS) with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) (OvSD/pSS/AAV) has been reported in other studies. This study applied the new criteria for AAV proposed by the American College of Rheumatology/European Alliance of Associations for Rheumatology in 2022 (the ACR/EULAR criteria) to patients with pSS presenting signs and symptoms suggestive of small- and medium-vessel vasculitis. It also investigated the overall frequency of OvSD/pSS/AAV and the major contributing factors to its reclassification. Methods: This study included 116 patients with pSS from March 2005 to December 2020, according to the inclusion criteria, and defined signs and symptoms suggestive of small- or medium-vessel vasculitides as lung parenchymal lesions supporting AAV, peripheral neuropathy, and suspected renal vasculitis. The classification could be made when the total scores for microscopic polyangiitis (MPA) and granulomatosis with polyangiitis (GPA) are ≥5 points and the eosinophilic GPA (EGPA) score is ≥6 points. Results: The median age of the patients was 56.0 years, and 101 patients (87.1%) were women. In total, 95, 12, and 37 patients had lung parenchymal lesions supporting AAV, peripheral neuropathy, and suspected renal vasculitis, respectively. According to the ACR/EULAR criteria for AAV, 35 of 116 (30.2%) patients were reclassified as having OvSD/pSS/AAV. Among these 35 patients, 4 were reclassified as having both OvSD/pSS/MPA and OvSD/pSS/GPA and 1 as having both OvSD/pSS/MPA and OvSD/pSS/EGPA simultaneously. The major contributing factor to the reclassification of OvSD/pSS/AAV was ANCA positivity. Conclusions: The overall frequency of the reclassification of OvSD/pSS/AAV was 30.2% in pSS patients presenting signs and symptoms suggestive of small- and medium-vessel vasculitis. Its likelihood increased according to ANCA positivity. Full article

Background: Microscopic polyangiitis (MPA) is a type of necrotizing vasculitis that primarily affects small vessels and belongs to the spectrum of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAVs). While previous studies have identified potential prognostic biomarkers, further research is needed to validate a reliable marker for risk stratification in clinical practice. Kidney injury molecule-1 (Kim-1), a transmembrane protein expressed on proximal tubular epithelial cells, has been implicated in tubular damage. This study investigated the potential of Kim-1 as a biomarker in MPA. Methods: Kidney biopsy tissues, along with urine and blood samples, were retrospectively analyzed from 52 MPA patients and compared to urine samples from 7 healthy controls. Global disease activity was assessed using the Birmingham vasculitis activity score (BVAS) and vasculitis damage index, while renal disease activity was evaluated using renal BVAS (BVAS-R). Results: Urinary Kim-1 levels were significantly elevated in MPA patients compared to healthy controls. Urinary Kim-1 was positively correlated with the Mayo Clinic Chronicity Score (MCCS) but not with the ANCA Kidney Risk Score (AKRiS), whereas tubular Kim-1 was associated with AKRiS but not with MCCS, indicating their distinct pathological significance. Higher tubular Kim-1 expression was observed in patients with elevated BVAS-R. Urinary Kim-1 levels correlated with proteinuria and were associated with the Mayo Clinic Chronicity Score (MCCS) and ANCA Kidney Risk Score (AKRiS) but not with glomerular lesion severity. Unlike C-reactive protein (CRP), neither urinary nor tubular Kim-1 predicted MPA recurrence. Conclusions: Urinary Kim-1 reflects histopathologic findings and renal impairment but does not predict systemic disease activity or recurrence in MPA, demonstrating its potential clinical utility as a biomarker for assessing chronic renal damage. Full article

Objective: Pulmonary involvement is commonly observed in anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), presenting with manifestations such as diffuse alveolar hemorrhage, inflammatory infiltrates, pulmonary nodules, and tracheobronchial disease. We aimed to identify distinct subgroups of tracheobronchial disease patterns in patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) using latent class analysis (LCA), and to evaluate their clinical characteristics and outcomes. Methods: We conducted a retrospective cohort study using electronic medical records of patients aged >18 years diagnosed with AAV and tracheobronchial disease between 1 January 2002 and 6 September 2022. Patients with follow-up <6 months were excluded. LCA was employed to identify disease subtypes based on 10 pre-defined indicators. Maximum likelihood estimation with 10 repetitions per model ensured robustness in model selection, guided by the Akaike information criterion (AIC). Patient and disease characteristics were summarized and compared across predicted classes. Statistical analyses included Kruskal–Wallis and Fisher’s exact tests for continuous and categorical variables, respectively. The primary outcome was time to relapse of the tracheobronchial inflammation after starting immunosuppressive medication, analyzed using the Kaplan–Meier method and log-rank tests. Secondary outcomes included severity of pulmonary disease on pulmonary function tests, endoscopic interventions, tracheostomy, or mortality during follow-up. Results: Among 136 identified AAV patients assessed for tracheobronchial involvement, 111 (81.6%) were included after excluding 25 without tracheal or bronchial disease. Predominant findings included subglottic stenosis (91.0%), lower tracheal stenosis (16.2%), and bronchial stenosis (17.1%). LCA identified a three-class model as optimal: tracheal predominant (n = 94), tracheobronchial (n = 12), and bronchial predominant (n = 5). Tracheal predominant patients showed reduced risk of ear, eye, and lower respiratory manifestations, with milder obstruction on pulmonary function testing (PFT). Tracheobronchial-class patients were prone to saddle nose deformity (50%), extensive lower respiratory involvement (91.7%), and renal disease (66.7%). Bronchial predominant patients exhibited severe obstructive disease (median forced expiratory volume in 1 s (FEV1)% predicted: 58, IQR 34–66; FEV1/forced vital capacity (FVC) ratio: 56.9, interquartile range (IQR) 43–63.3) but lacked systemic AAV manifestations. LCA classes did not predict outcomes such as endoscopic intervention, tracheostomy, recurrent tracheobronchial narrowing, or mortality. Conclusion: LCA shows promise in subtype stratification of AAV patients, yet its utility in predicting outcomes and guiding treatment remains limited based on our analysis. Future studies with enhanced phenotypic data and larger cohorts are warranted to improve predictive accuracy. Full article

Antineutrophil cytoplasmic antibody-associated (ANCA) vasculitis are a group of autoimmune diseases characterized by inflammation of the microvasculature, leading to life-threatening complications, including kidney disease. These diseases are associated with a high morbidity and mortality rate. Conventional treatment modalities have evolved towards personalized therapies intending to mitigate inflammation and minimize the adverse effects of traditional immunosuppressive agents. Avacopan, a novel C5a receptor inhibitor, represents a promising therapeutic option for vasculitis with renal involvement. This article provides a comprehensive review of the role of complement in the pathogenesis of vasculitis with renal involvement and the role of avacopan for its treatment, taking into account recent updates to both the EULAR and KDIGO guidelines and published experience of avacopan use in real clinical settings. 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

Objective: Functional magnetic resonance imaging (fMRI) has been applied to assess the microstructure of the kidney. However, it is not clear whether fMRI could be used in the field of kidney injury in patients with Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). Methods: This study included 20 patients with AAV. Diffusion kurtosis imaging (DKI) and blood oxygen level-dependent (BOLD) scanning of the kidneys were performed in AAV patients and healthy controls. The mean kurtosis (MK), mean diffusivity (MD), and fractional anisotropy (FA) parameters of DKI, the R2* parameter of BOLD, and clinical data were further analyzed. Results: In AAV patients, the cortex exhibited lower MD but higher R2* values compared to the healthy controls. Medullary MK values were elevated in AAV patients. Renal medullary MK values showed a positive correlation with serum creatinine levels and negative correlations with hemoglobin levels and estimated glomerular filtration rate. To assess renal injury in AAV patients, AUC values for MK, MD, FA, and R2* in the cortex were 0.66, 0.67, 0.57, and 0.55, respectively, and those in the medulla were 0.81, 0.77, 0.61, and 0.53, respectively. Conclusions: Significant differences in DKI and BOLD MRI parameters were observed between AAV patients with kidney injuries and the healthy controls. The medullary MK value in DKI may be a noninvasive marker for assessing the severity of kidney injury in AAV patients. Full article

As vaccinations against the SARS-CoV-2 virus have become a crucial tool in controlling the spread of the disease, reports of rare health complications have emerged, including new-onset antineutrophil cytoplasmic autoantibodies (ANCA)-associated vasculitis (AAV). We systematically reviewed new-onset AAV following COVID-19 vaccination case reports and case series published in three databases before January 2024 following PRISMA guidelines to understand the characteristics of possible causal relationships or coincidences. In total, 404 articles were screened respectively by title, abstracts, and full-texts. Thirty-four papers fulfilled the inclusion criteria and have been analyzed, covering 44 patients with new-onset AAV after COVID-19 vaccination with no prior history of COVID-19 infection. Data regarding patients’ metrics, comorbidities, vaccination characteristics, symptoms, diagnostics, treatment, and outcomes were investigated and summarized. The cohort consisted predominantly of females. AAV diagnosis was confirmed via biopsy, with renal dysfunction as a prevailing manifestation. In most cases, the first symptoms of AAV developed after the second dose; moreover, Pfizer-BioNTech was the most frequently administered vaccine among the analyzed cohort. Primary treatment involved glucocorticoid therapy, with a mostly favourable response. This systematic review aims to raise awareness among clinicians in the field regarding this rare but possible complication, to promote the prompt recognition and diagnosis of de novo ANCA-positive small-vessel vasculitis in timely association with SARS-CoV-2 vaccination. Full article

The inflammasome regulates the innate inflammatory response and is involved in autoimmune diseases. In this study, we explored the levels of IL-18 and IL-1β in serum and urine and the influence of various single-nucleotide polymorphisms (SNPs) on kidney lesions at diagnosis in patients with ANCA-associated vasculitis (AAV) and their clinical outcomes. Ninety-two patients with renal AAV were recruited, and blood and urine were collected at diagnosis. Serum and urine cytokine levels were measured by ELISA. DNA was extracted and genotyped using TaqMan assays for SNPs in several inflammasome genes. Lower serum IL-18 (p = 0.049) and the IL-18 rs187238 G-carrier genotype (p = 0.042) were associated with severe fibrosis. The IL-18 rs1946518 TT genotype was associated with an increased risk of relapse (p = 0.05), whereas GG was related to better renal outcomes (p = 0.031). The rs187238 GG genotype was identified as a risk factor for mortality within the first year after AAV diagnosis, independent of the requirement for dialysis or lung involvement (p = 0.013). We suggest that decreased cytokine levels could be a surrogate marker of scarring and chronicity of the renal lesions, together with the rs187238 GG genotype. If our results are validated, the rs1946518 TT genotype predicts the risk of relapse and renal outcomes during follow-up. Full article

Keratins are the main components of the cell cytoskeleton of epithelial cells. Epithelial cells under stressful stimuli react by modifying their keratin expression pattern. Glomerular diseases are pathological conditions that may lead to loss of kidney function if not timely diagnosed and treated properly. This study aims to examine glomerular and tubular keratin expression in podocytopathies, ANCA-associated vasculitis, and IgA nephropathy and how this expression correlates to clinical outcomes. We included 45 patients with podocytopathies (minimal change disease and focal segmental glomerulosclerosis), ANCA-associated vasculitis, and IgA nephropathy, with or without crescentic lesions, and healthy controls. All tissues were assessed by photon microscopy and immunohistochemistry. Biopsy sections were examined for keratins 7, 8, 18, and 19 expression in the glomerular and tubulointerstitial areas separately. Moreover, we examined how keratin expression was correlated with long-term kidney function outcomes. All four studied keratins had significantly increased glomerular expression in patients with ANCA vasculitis compared to controls and MCD patients. Tubular expression of keratins 7, 8, and 19 was related to kidney outcome in all groups. Patients with crescents had higher expression of all keratins in both glomeruli and tubulointerstitium. The presence of tubular atrophy, interstitial fibrosis, mesangial hyperplasia, and interstitial inflammation did not affect keratin expression. Keratins, an abundant component of renal epithelial cells, have the potential to be featured as a biomarker for kidney function prognosis in patients with glomerular diseases. Full article

Background: Previous studies indicated common thyroid dysfunction in various kidney diseases. This study aimed to investigate the thyroid function in patients with antineutrophil cytoplasmic antibody-associated vasculitis (AAV) with renal injury. Methods: Briefly, 174 patients diagnosed as having AAV with renal injury and without previous thyroid disease history were included in the retrospective and prospective study. The clinical parameters were collected and compared between different groups. Results: Of the patients included, 24 exhibited normal thyroid function, while 150 had thyroid dysfunction, including 55 (36.67%) with hypothyroidism. Those AAV patients with thyroid dysfunction showed different clinical parameters from those with normal thyroid function. The patients were followed up for a median of 68.6 (64.3; 72.8) months. Those with thyroid dysfunction were more prone to progressing to dialysis dependence compared to the group with normal thyroid function. Logistic regression analysis showed advanced age and decreased albumin as independent risk factors for thyroid dysfunction in patients with AAV. Survival analysis and multivariate Cox regression analysis showed that thyroid dysfunction was a risk factor for AAV patients with renal injury to progress to the endpoint of dialysis dependence. Conclusion: Thyroid dysfunction, predominantly hypothyroidism, was commonly complicated in AAV patients with renal injury. AAV patients with thyroid dysfunction were presented with different clinical parameters and more prone to progressing to dialysis dependence compared to those with normal thyroid function. Full article

Involvement of the complement system is key to the pathogenesis of antineutrophil cytoplasmic antibody (ANCA)-associated renal vasculitis, but immunometabolic implications, especially on serum uric acid (UA) levels, still need to be elucidated. A total of 34 patients with biopsy-proven ANCA-associated renal vasculitis between 2015 and 2020 were retrospectively enrolled. Serum UA levels were correlated with clinical and histopathological characteristics, separated for critically ill (CI, n = 19), myeloperoxidase (MPO)-ANCA (n = 21) and proteinase 3 (PR3)-ANCA (n = 13) subgroups. We here identified inverse correlations of serum UA levels and complement C3 levels in the total cohort (p = 0.005) and the CI subgroup (p < 0.001). Intrarenal complement C4d deposition in venules correlated with serum UA levels in the total cohort (p = 0.007) and in the CI subgroup (p = 0.016). Significant associations of serum UA levels and tubulitis in areas of scarred cortex (t-IFTA) were identified in the total cohort (p = 0.008), and both subgroups of CI (p = 0.034) and MPO-ANCA (p = 0.029). In PR3-ANCA, interstitial fibrosis (ci) was observed as the strongest association with serum UA levels (p = 0.022). Our observations broaden our current understanding of contributory metabolic factors that influence the initial disease course in ANCA-associated renal vasculitis. Full article

The present study applied the 2022 American College of Rheumatology and European Alliance of Associations for Rheumatology classification criteria (the 2022 ACR/EULAR criteria) for antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) to ANCA-positive patients with polymyositis (PM)/dermatomyositis (DM). Also, this study investigated how many patients could be diagnosed with overlap syndrome consisting of PM/DM and AAV. Twelve ANCA-positive patients with PM/DM were included and analysed in this study. The 2022 ACR/EULAR classification criteria for microscopic polyangiitis (MPA), granulomatosis with polyangiitis (GPA), and eosinophilic GPA (EGPA) are scoring systems, and when a total score is over five in cases of MPA and GPA and over six in cases of EGPA, AAV can be classified. The median age of 12 ANCA-positive patients (six with PM and six with DM) was 54.0 years and one patient (8.3%) was male. Of the 12 ANCA-positive patients with PM/DM, 11 had myeloperoxidase (MPO)-ANCA (or perinuclear [P]-ANCA) and the remaining one had proteinase 3 (PR3)-ANCA (or cytoplasmic [C]-ANCA). Nine (75.5%) and one (8.3%) ANCA-positive patients with PM/DM were diagnosed with overlap syndrome consisting of PM/DM and MPA and overlap syndrome consisting of PM/DM and GPA, respectively. The main contributors to the classification of MPA and GPA were interstitial lung disease and renal vasculitis, along with ANCA positivity, respectively. In conclusion, this study was the first to demonstrate that 83.3% of them could be diagnosed with overlap syndrome consisting of PM/DM and AAV according to the 2022 ACR/EULAR criteria for AAV. 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