LabMedica

Download Mobile App
Recent News Expo Clinical Chem. Molecular Diagnostics Hematology Immunology Microbiology Pathology Technology Industry Focus

Testing Methods Compared for Myositis Specific Autoantibodies

By LabMedica International staff writers
Posted on 28 Jun 2016
Print article
Image: A histopathology of polymyositis showing endomysial mononuclear inflammatory infiltrate and muscle fiber necrosis (Photo courtesy of Ramesh Pappu, MD, DPH).
Image: A histopathology of polymyositis showing endomysial mononuclear inflammatory infiltrate and muscle fiber necrosis (Photo courtesy of Ramesh Pappu, MD, DPH).
The performance of a line blot assay for the identification of autoantibodies in sera of patients affected by myositis has been compared with immunoprecipitation (IP) as gold standard.

Myositis refers to any condition causing inflammation in muscles and weakness, swelling, and pain are the most common myositis symptoms. Myositis causes include infection, injury, autoimmune conditions, and drug side effects and treatment of myositis varies according to the cause.

Immunologists at the University of Brescia (Italy) and their colleagues tested sera of 66 sera of patients with myositis, 23 polymyositis, eight anti-synthetase syndromes, 29 dermatomyositis and six overlap syndromes, by a commercial line blot (LB, Euroimmun, Lubeck, Germany); 57 sera were analyzed also by IP of K562 cell extract radiolabeled with 35S-methionine. Inter-rater agreement was calculated with Cohen's κ coefficient.

The scientists found that myositis-specific antibodies (MSA) could be detected in 36/57 (63%) of sera by IP and in 39/66 (59%) of sera by LB. The most frequent MSA found by LB were anti- histidyl tRNA synthetase (Jo1) and anti-Mi2 nuclear antigen found in 15% (10/66) of sera, followed by anti- nuclear matrix protein 2 (NXP2) and anti- signal recognition particle (SRP) detected in 10.6% (7/66) of sera. Anti- transcriptional intermediary factor 1 gamma (TIF1γ) and anti- Melanoma Differentiation-Associated protein 5 (MDA5) were found in six (9%) and five sera (7.6%), respectively.

The authors concluded that the use of the LB assay allowed the detection of new MSA, such as anti-MDA5, anti-MJ and anti-TIF1gamma antibodies, previously not found with routine methods. However, the high prevalence of multiple positives and the high discordant rate of anti-Jo1 antibodies could create some misinterpretation of the results from the clinical point of view. The study was published in the June 2016 issue of the Journal of Immunological Methods.

Related Links:
University of Brescia
Euroimmun
New
Gold Member
Rotavirus Test
Rotavirus Test - 30003 – 30073
Verification Panels for Assay Development & QC
Seroconversion Panels
New
Silver Member
ACTH Assay
ACTH ELISA
New
Dermatophytosis Rapid Diagnostic Kit
StrongStep Dermatophytosis Diagnostic Kit

Print article

Channels

Molecular Diagnostics

view channel
Image: The Mirvie RNA platform predicts pregnancy complications months before they occur using a simple blood test (Photo courtesy of Mirvie)

RNA-Based Blood Test Detects Preeclampsia Risk Months Before Symptoms

Preeclampsia remains a major cause of maternal morbidity and mortality, as well as preterm births. Despite current guidelines that aim to identify pregnant women at increased risk of preeclampsia using... Read more

Microbiology

view channel
Image: The lab-in-tube assay could improve TB diagnoses in rural or resource-limited areas (Photo courtesy of Kenny Lass/Tulane University)

Handheld Device Deliver Low-Cost TB Results in Less Than One Hour

Tuberculosis (TB) remains the deadliest infectious disease globally, affecting an estimated 10 million people annually. In 2021, about 4.2 million TB cases went undiagnosed or unreported, mainly due to... Read more

Technology

view channel
Image: Schematic illustration of the chip (Photo courtesy of Biosensors and Bioelectronics, DOI: https://doi.org/10.1016/j.bios.2025.117401)

Pain-On-A-Chip Microfluidic Device Determines Types of Chronic Pain from Blood Samples

Chronic pain is a widespread condition that remains difficult to manage, and existing clinical methods for its treatment rely largely on self-reporting, which can be subjective and especially problematic... Read more

Industry

view channel
Image: The collaboration aims to leverage Oxford Nanopore\'s sequencing platform and Cepheid\'s GeneXpert system to advance the field of sequencing for infectious diseases (Photo courtesy of Cepheid)

Cepheid and Oxford Nanopore Technologies Partner on Advancing Automated Sequencing-Based Solutions

Cepheid (Sunnyvale, CA, USA), a leading molecular diagnostics company, and Oxford Nanopore Technologies (Oxford, UK), the company behind a new generation of sequencing-based molecular analysis technologies,... Read more
Sekisui Diagnostics UK Ltd.