Objectives: Today, the contribution of myositis-specific autoantibodies (MSA) in the diagnostic workup of idiopathic inflammatory myopathies (IIM) is on the rise. The aim of this study was to document MSA frequency as detected by lineblot in a set of consecutive MSA requests and to correlate the results with clinical diagnosis, IIM subtype and indirect immunofluorescence (IIF) findings. Additionally, a comparison between two lineblots was performed.

Methods: A total of 118 consecutive samples of patients with suspicion of IIM were analysed on IIF and two lineblots. A total of 107 patients with autoimmune rheumatic diseases served as controls.

Results: MSA were detected in 55% of IIM patients (n=31) and 7.9% (n=12) of patients without clinical diagnosis of IIM or myositis overlap syndrome. All the IIM patients had a MSA-compatible clinical subtype. There was no to fair agreement between both lineblots for the individual antibodies, with most discrepancies observed for anti-TIF1γ (κ=-0.021), anti-SRP (κ=-0.006) and anti-SAE (κ=0.395). Differences between both assays were mostly observed in the non-IIM patients, also showing signi cantly lower blot signal intensities compared to IIM patients (p=0.0013). MSA in the non-IIM patients frequently showed an incompatible IIF pattern.

Conclusions: Lineblot seems to be an interesting tool for MSA detection in a clinical context, allowing the identification of clinical subtypes. However, considerable caution must be exercised in interpreting the results in case of low positive MSA signal intensity, discordant lineblot results and/or an incompatible IIF pattern.

Download full-text PDF

Source
http://dx.doi.org/10.55563/clinexprheumatol/3cuc1sDOI Listing

Publication Analysis

Top Keywords

iim patients
12
idiopathic inflammatory
8
clinical diagnosis
8
diagnosis iim
8
patients
8
non-iim patients
8
incompatible iif
8
msa
7
iim
7
clinical
5

Similar Publications

Human PBMC-based humanized mice exhibit myositis features and serve as a drug evaluation model.

Inflamm Regen

January 2025

Oncology & Immunology Unit, Research Division, Mitsubishi Tanabe Pharma Corporation, Kanagawa, 227-0033, Japan.

Idiopathic inflammatory myopathies (IIMs) are a group of autoimmune disorders characterized by immune cell infiltration of muscle tissue accompanied by inflammation. Treatment of IIMs is challenging, with few effective therapeutic options due to the lack of appropriate models that successfully recapitulate the features of IIMs observed in humans. In the present study, we demonstrate that immunodeficient mice transplanted with human peripheral blood mononuclear cells (hPBMCs) exhibit the key pathologic features of myositis observed in humans and develop graft-versus-host disease.

View Article and Find Full Text PDF

Objective: Older age, dermatomyositis, and specific serum autoantibodies such as anti-TIF1-γ are associated with higher cancer risk in patients with myositis. We evaluated a vast cohort of patients with myositis for the prevalence of cancer, the association to disease features, and the performance of the recent IMACS guidelines.

Methods: A retrospective cohort analysis was performed and in all cases serum autoantibodies were tested using HEp-2, immunoassays, RNA- and protein-immunoprecipitation.

View Article and Find Full Text PDF

Objective: To evaluate the main outcomes of disease activity and their association with other measures of activity, damage, and quality of life in patients with idiopathic inflammatory myopathy (IIM) according to time since diagnosis and positivity to antisynthetase autoantibodies (ASAs).

Methods: Cross-sectional multicenter study within the Spanish Myo-Spain registry. Cases were classified as incident (≤ 12 months since diagnosis) and prevalent.

View Article and Find Full Text PDF

Objectives: Objective of this work was to examine myomiR levels in plasma, skeletal muscle, and skeletal muscle cells of patients with idiopathic inflammatory myopathy (IIM), their interrelations with the disease-related clinical phenotypes and with the effects of the disease-modifying 6-month training-intervention.

Methods: Samples of vastus lateralis muscle (n = 12/13) and plasma (n = 20/21) were obtained from IIM patients and healthy controls, respectively. Muscle and plasma were obtained before and after a 6-month training-intervention in 7 patients.

View Article and Find Full Text PDF

: Emerging evidence suggests that SARS-CoV-2 infection and vaccines may trigger autoimmune responses in predisposed individuals. Idiopathic inflammatory myopathies (IIMs) are diseases with diverse clinical manifestations, often associated with myositis autoantibodies (MAs). Diagnosing IIM is challenging due to limitations in classification criteria and diagnostic assays.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!