Publications by authors named "Nader Khalidi"

Background: Traditional medical research infrastructures relying on the Centers of Excellence (CoE) model (an infrastructure or shared facility providing high standards of research excellence and resources to advance scientific knowledge) are often limited by geographic reach regarding patient accessibility, presenting challenges for study recruitment and accrual. Thus, the development of novel, patient-centered (PC) strategies (e.g.

View Article and Find Full Text PDF

Objectives: There are an increasing number of centers performing research on high-resolution vessel wall magnetic resonance imaging (VW-MRI) in giant cell arteritis (GCA). However, harmonized approaches to VW-MRI in GCA are lacking and are essential to performing multicentre studies. Using a data-driven, consensus-based approach, an international expert group developed a standardized MRI protocol and scoring system to advance multi-centered research in cranial GCA.

View Article and Find Full Text PDF
Article Synopsis
  • - This study aimed to find plasma protein patterns that can differentiate between active and inactive giant cell arteritis (GCA) patients and healthy controls by analyzing their plasma samples.
  • - Researchers collected samples from 30 GCA patients and 30 matched controls, using a high-tech proteomics assay that evaluated over 7000 proteins, identifying significant differences in protein levels related to disease activity.
  • - The results revealed specific proteins linked to GCA and showed strong potential for using machine learning models to identify different disease states, although distinguishing between active and inactive states in the same patient was challenging.
View Article and Find Full Text PDF

Objective: Signal regulatory protein α (SIRPα) is found primarily on myeloid cells, including macrophages and neutrophils; binds to CD47; and regulates phagocytosis, antigen presentation, cellular fusion, cell proliferation, and migration. Therefore, SIRPα may be involved in the pathogenesis of autoimmune diseases, including systemic vasculitis. This study aimed to assess SIRPα expression in tissue samples from patients with vasculitis.

View Article and Find Full Text PDF

Objectives: To evaluate damage and clinical characteristics associated with damage in Takayasu's arteritis (TAK).

Methods: Patients with TAK enrolled in a multicentre, prospective, observational study underwent standardized damage assessment every 6 months using the Vasculitis Damage Index (VDI) and the Large-Vessel Vasculitis Index of Damage (LVVID).

Results: The study included 236 patients with TAK: 92% female, 81% Caucasian; median (25th, 75th percentile) disease duration = 2.

View Article and Find Full Text PDF

Background: Giant cell arteritis is an age-related vasculitis that mainly affects the aorta and its branches in individuals aged 50 years and older. Current options for diagnosis and treatment are scarce, highlighting the need to better understand its underlying pathogenesis. Genome-wide association studies (GWAS) have emerged as a powerful tool for unravelling the pathogenic mechanisms involved in complex diseases.

View Article and Find Full Text PDF

Objective: The interpretation of magnetic resonance imaging (MRI) reports is crucial for the diagnosis of axial spondyloarthritis, but the subjective nature of narrative reports can lead to varying interpretations. This study presents a validation of a novel MRI reporting system for the sacroiliac joint in clinical practice.

Methods: A historical review was conducted on 130 consecutive patients referred by 2 rheumatologists for initial MRI assessment of possible axial spondyloarthritis.

View Article and Find Full Text PDF

Objective: Relapses of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis are important events that can cause organ dysfunction and reduce quality of life. Understanding the effects of the initial treatments for ANCA-associated vasculitis on the subsequent risk of relapse may help guide monitoring and treatment.

Methods: We performed a post hoc analysis of participants with severe ANCA-associated vasculitis enrolled in an international two-by-two factorial randomized controlled trial comparing the effects of plasma exchange (PLEX) to no PLEX and a regimen of reduced glucocorticoid exposure to a standard regimen.

View Article and Find Full Text PDF
Article Synopsis
  • The study investigates how common cerebrovascular events (CVEs) are in patients diagnosed with primary systemic vasculitis (PSV) and identifies factors linked to these events.
  • It involved analyzing data from over 4,800 adults with PSV, revealing that 3.50% experienced CVEs, primarily strokes and transient ischemic attacks (TIAs), with the highest rates in certain types of vasculitis like Behçet's disease.
  • The findings highlight that CVEs are prevalent among PSV patients, vary significantly depending on the type of vasculitis, and recur at a high rate, indicating that traditional vascular risk factors do not account for these events.
View Article and Find Full Text PDF
Article Synopsis
  • The study gathered data on 358 patients with polyarteritis nodosa (PAN) from nine countries, analyzing demographics, clinical features, and survival rates over 30 years.
  • Findings showed common symptoms such as constitutional issues, skin lesions, joint pain, and neurological problems, with a significant relapse rate of 48.5% during an average follow-up of nearly five years.
  • Survival rates for systemic PAN showed a decline over time, with important risk factors for mortality including older age, high serum creatinine levels, and involvement of the gastrointestinal system or central nervous system.
View Article and Find Full Text PDF

Introduction: Although the alternative complement pathway has been implicated in the pathogenesis of antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV), the specific nature of its involvement is unclear. This study measured levels of urine and plasma complement fragment Ba at multiple time points in a group of patients with AAV.

Methods: The complement fragment Ba was measured by enzyme-linked immunosorbent assay in serial urine and plasma samples from 21 patients with AAV who developed a renal flare, 19 who developed a nonrenal flare, and 20 in long-term remission.

View Article and Find Full Text PDF

Background: Respiratory conditions, such as asthma, are infrequently associated with auto-inflammatory diseases. We describe five patients with uncontrolled respiratory symptoms that were seen at St. Joesph's Healthcare in Hamilton for severe asthma management diagnosed with rare autoinflammatory conditions using genetic molecular analysis.

View Article and Find Full Text PDF

Markers of extracellular mitochondria are present in giant cell arteritis (GCA) patients. However, their role in promoting inflammation and platelet activation is no known. To investigate this, isolated mitochondria were opsonized with plasma from GCA patients or healthy individuals and incubated with peripheral blood mononuclear cells (PBMCs) or platelets and assessed for inflammatory cytokine production and platelet activation.

View Article and Find Full Text PDF

Objective: This study examined the relationship between age at diagnosis and disease characteristics and damage in patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV).

Methods: Analysis of a prospective longitudinal cohort of patients with granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic GPA (EGPA) in the Vasculitis Clinical Research Consortium (2013-2021). Disease cohorts were divided by age at diagnosis (years): children (<18), young adults (18-40), middle-aged adults (41-65), and older adults (>65).

View Article and Find Full Text PDF

Objective: Following induction of remission with rituximab in anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) relapse rates are high, especially in patients with history of relapse. Relapses are associated with increased exposure to immunosuppressive medications, the accrual of damage and increased morbidity and mortality. The RITAZAREM trial compared the efficacy of repeat-dose rituximab to daily oral azathioprine for prevention of relapse in patients with relapsing AAV in whom remission was reinduced with rituximab.

View Article and Find Full Text PDF
Article Synopsis
  • This study measured levels of neutrophil extracellular traps (NETs) in the plasma of healthy individuals and various patients with different types of vasculitis to understand their role in disease activity.
  • It found that NET levels were significantly higher during active disease phases in patients with granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), Takayasu's arteritis (TAK), and giant cell arteritis (GCA), indicating a link between NETs and disease severity.
  • Additionally, the study suggested that increased levels of the thrombospondin-1 (TSP-1) protein were associated with NET formation, highlighting the potential of targeting NETs in developing new treatments for these
View Article and Find Full Text PDF

Objective: Vitamin D might participate in the pathogenesis of several immune-mediated diseases, but few related data are available for ANCA-associated vasculitis (AAV). In this study, we analysed the association between vitamin D status and disease in patients with AAV.

Methods: Serum levels of 25(OH)D were measured in 125 randomly selected patients with AAV [granulomatosis with polyangiitis ( = 50), eosinophilic granulomatosis with polyangiitis ( = 50) or microscopic polyangiitis ( = 25)] enrolled in the Vasculitis Clinical Research Consortium Longitudinal Studies at the time of enrolment and a subsequent relapse visit.

View Article and Find Full Text PDF

Objective: In 2020, the Canadian Vasculitis Research Network (CanVasc) published their updated recommendations for the management of ANCA-associated vasculitides (AAV). The current addendum provides further recommendations regarding the use of avacopan in AAV based on a review of newly available evidence.

Methods: An updated systematic literature review on avacopan (formerly, CCX168) using Medline, Embase, and the Cochrane Library was performed for publications up to September 2022.

View Article and Find Full Text PDF

Objectives: ANCA-associated vasculitis (AAV) is a group of multisystem diseases that can have several ocular manifestations. There are published data on ocular manifestations of granulomatosis with polyangiitis (GPA), but few for eosinophilic granulomatosis with polyangiitis (EGPA) or microscopic polyangiitis (MPA). There is little information concerning chronicity, complications, and association with other cranial manifestations of AAV.

View Article and Find Full Text PDF

Objective: Diffuse cutaneous systemic sclerosis (SSc) is a highly heterogeneous disease. A provisionally approved Composite Response Index in diffuse cutaneous SSc (CRISS) was developed as a 1-year outcome measure for clinical trials. Our goal was to further validate the CRISS by examining agreement between CRISS definitions for improved/non-improved with physicians' evaluation of disease.

View Article and Find Full Text PDF

Objectives: Temporal artery magnetic resonance angiography (TAMRA) is a useful tool to investigate possible diagnoses of GCA. As acquired images also reveal other local structures, they may assist in finding alternative diagnoses when assessing for possible GCA. We sought to assess the utility of TAMRA in identifying other significant abnormalities either associated with a diagnosis of GCA or potentially mimicking a clinical presentation of GCA.

View Article and Find Full Text PDF

Background: Anti-neutrophil cytoplasm antibody-associated vasculitis is a multisystem, autoimmune disease that causes organ failure and death. Physical removal of pathogenic autoantibodies by plasma exchange is recommended for severe presentations, along with high-dose glucocorticoids, but glucocorticoid toxicity contributes to morbidity and mortality. The lack of a robust evidence base to guide the use of plasma exchange and glucocorticoid dosing contributes to variation in practice and suboptimal outcomes.

View Article and Find Full Text PDF

Background: Local airway autoimmune responses may contribute to steroid dependence and persistent eosinophilia in severe asthma. Auto-IgG antibodies directed against granule proteins such as eosinophil peroxidase (EPX), macrophage scavenger receptor with collagenous structure (MARCO) and nuclear/extranuclear antigens (antinuclear antibodies (ANAs)) have been reported. Our objective was to describe the prevalence and clinical characteristics of asthmatic patients with airway autoreactivity, and to assess if this could be predicted from clinical history of autoreactivity.

View Article and Find Full Text PDF

Objective: To assess markers of neutrophil activation such as calprotectin and N-formyl methionine (fMET) in anti-neutrophil cytoplasmic autoantibody-associated vasculitis (AAV) and large-vessel vasculitis (LVV).

Methods: Levels of fMET, and calprotectin, were measured in the plasma of healthy controls (n=30) and patients with AAV (granulomatosis with polyangiitis (GPA, n=123), microscopic polyangiitis (MPA, n=61)), and LVV (Takayasu's arteritis (TAK, n=58), giant cell arteritis (GCA, n=68)), at times of remission or flare. Disease activity was assessed by physician global assessment.

View Article and Find Full Text PDF