Publications by authors named "Peter Merkel"
Therapeutic plasma exchange (PLEX) is an adjunctive treatment for patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis and kidney involvement. Little is known about the effect of PLEX on early changes in kidney function. This post-hoc analysis of the PEXIVAS trial investigated the effects of PLEX on changes in kidney function within 12 months.
View Article and Find Full Text PDFBackground: 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 PDFObjectives: 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 PDFAdvancing composite outcome measures: Insights on weighting components from OMERACT 2023.
Semin Arthritis Rheum
December 2024
Article Synopsis
- The OMERACT Composite Working Group held a workshop in 2023 to discuss how to effectively weight components in composite outcomes, highlighting its complexities.
- The workshop included presentations on composite outcomes, a patient narrative, and engaging activities for participants to rank and assign weights to different domains.
- Findings revealed challenges in achieving consensus on domain importance, emphasizing the need for systematic methods and the inclusion of patient perspectives in future composite outcome research.
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.
Rationale & Objective: Research in anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) has focused on reducing treatment toxicities, notably through reduction of exposure to glucocorticoids. Glucocorticoid-sparing therapies such as avacopan are not widely available in many countries, and patients are exposed to high glucocorticoid doses. There is little data concerning what clinicians should accept as the lowest glucocorticoid dosing that can be used in induction therapy for AAV.
View Article and Find Full Text PDFAdvancements and challenges in CAR T cell therapy in autoimmune diseases.
Nat Rev Rheumatol
September 2024
Article Synopsis
- CAR T cells are special immune cells that can target and destroy B cells, which are often involved in certain cancers and autoimmune diseases.
- This therapy is used to help patients who have tough-to-treat B cell cancers and has also shown promise for helping with autoimmune diseases like lupus and multiple sclerosis.
- Researchers are studying how CAR T cell therapy can improve the immune system by getting rid of bad B cells, and they are figuring out the best ways to use this treatment safely and effectively for patients.
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 PDFObjectives: 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.
Objective: There are limited data on the reproductive health of women with vasculitis. This study used a prospective, international vasculitis pregnancy registry to survey women during and after pregnancy.
Methods: The Vasculitis Pregnancy Registry (VPREG) is imbedded within the Vasculitis Patient-Powered Research Network, an international online research infrastructure.
Article Synopsis
- The study examined the reproductive experiences of women with vasculitis, focusing on their healthcare conversations, treatment changes, and delivery outcomes.
- Conducted through interviews with participants from the Vasculitis Pregnancy Registry, the research highlighted the importance of tracking patient perspectives and experiences regarding pregnancy planning and care.
- Findings revealed that women often took an active role in discussions about family planning, relying heavily on their doctors’ advice while also advocating for themselves amid varying medical opinions.
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 PDFArticle Synopsis
- The study focuses on improving the identification of relapses in ANCA-associated vasculitis (AAV) by creating a computable phenotype (CP) using real-world data from a patient registry.
- Researchers followed a detailed five-step process to develop and validate the CP, identifying five key data elements that indicate relapse, such as changes in ANCA levels and immunosuppression status.
- The resulting CP demonstrated high accuracy in predicting relapses, with strong sensitivity and specificity, suggesting its utility for future outcomes assessment in similar diseases.
Objectives: To determine the incidence rate (IR) of myocardial infarction (MI), relative risk of MI, and impact of incident MI on mortality in individuals with biopsy-confirmed giant cell arteritis (GCA).
Methods: MIs in individuals diagnosed with GCA 1998-2016 in Skåne, Sweden were identified by searching the SWEDEHEART register, a record of all patients receiving care for MI in a coronary care unit (CCU). The regional diagnosis database, with subsequent case review, identified GCA patients receiving care for MI outside of a CCU.
Objective: Relapses are frequent and difficult to predict in antineutrophil cytoplasmic antibody-associated vasculitis (AAV), resulting in long-term use of immunosuppression. Although sinonasal disease is associated with relapse of AAV, detailed characterization of sinonasal symptoms is lacking. Using a patient-reported outcome, the 22-item SinoNasal Outcome Test (SNOT-22), we investigated the relationship between sinonasal symptoms and disease activity in AAV.
View Article and Find Full Text PDFObjective: 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.
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.
Background: Eosinophilic granulomatosis with polyangiitis (EGPA) is a vasculitis characterized by eosinophilic inflammation. Benralizumab, a monoclonal antibody against the interleukin-5α receptor expressed on eosinophils, may be an option for treating EGPA.
Methods: We conducted a multicenter, double-blind, phase 3, randomized, active-controlled noninferiority trial to evaluate the efficacy and safety of benralizumab as compared with mepolizumab.
Diffuse alveolar hemorrhage (DAH) is a life-threatening manifestation of antineutrophil cytoplasmic antibody-associated vasculitis (AAV). The PEXIVAS (Plasma Exchange and Glucocorticoids in Severe Antineutrophil Cytoplasmic Antibody-Associated Vasculitis) (NCT00987389) trial was the largest in AAV and the first to enroll participants with DAH requiring mechanical ventilation. Evaluate characteristics, treatment effects, and outcomes for patients with AAV with and without DAH.
View Article and Find Full Text PDFArticle 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.
Objective: To explore, from patients' perspectives, the symptoms and impact of Raynaud's phenomenon (RP) on the feet of patients with systemic sclerosis (SSc-RP), and to identify which foot-related domains are important to patients.
Methods: Forty participants (34 women) with SSc-RP took part in one of six focus groups held in the United Kingdom or United States. Participants were purposively sampled to ensure diversity in disease type, duration, and ethnicity.
Article Synopsis
- The study investigates the use of magnetic resonance imaging (MRI) to evaluate potential visual impairment in giant cell arteritis (GCA), even in patients who show no visual symptoms.
- Out of 64 patients suspected of having GCA, MRI detected significant orbital enhancement in many cases, indicating its effectiveness in diagnosing both ocular and nonocular GCA.
- Results showed that MRI enhancement correlated with inflammation levels and decreased post-treatment, prompting further research on MRI's role in identifying patients at lower risk for blindness who might require reduced glucocorticoid therapy.
Background: The ADVOCATE trial, in which the complement C5a receptor inhibitor avacopan was compared with a standard prednisone taper in patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis, used the Glucocorticoid Toxicity Index (GTI) to measure glucocorticoid toxicity change. We set out to do a post-hoc analysis of the ADVOCATE data to evaluate changes in individual GTI domains and their ability to differentiate treatment groups.
Methods: The ADVOCATE trial was a phase 3, double-blind, double-dummy, randomised trial comparing oral avacopan (30 mg) twice daily for 52 weeks plus a prednisone-matching placebo for 20 weeks with oral prednisone tapered over 20 weeks plus an avacopan-matching placebo for 52 weeks in patients with ANCA-associated vasculitis.