A1 Refereed original research article in a scientific journal
Evaluation of a New Skeletal Troponin I Assay in Patients with Idiopathic Inflammatory Myopathies
Authors: Katriina Bamberg, Laura Mehtälä, Olli Arola, Seppo Laitinen, Pauliina Nordling, Marjatta Strandberg, Niko Strandberg, Johanna Paltta, Markku Mali, Fabricio Espinosa-Ortega, Laura Pirilä, Ingrid E Lundberg, Tanja Savukoski, Kim Pettersson
Publisher: OXFORD UNIV PRESS INC
Publication year: 2020
Journal: The Journal of Applied Laboratory Medicine
Journal name in source: JOURNAL OF APPLIED LABORATORY MEDICINE
Journal acronym: J APPL LAB MED
Volume: 5
Issue: 2
First page : 320
Last page: 331
Number of pages: 12
eISSN: 2475-7241
DOI: https://doi.org/10.1093/jalm/jfz016(external)
Abstract
Background:The
current biomarkers for diagnosis and monitoring of injured and diseased
skeletal muscles, such as creatine kinase (CK), have limited tissue
specificity and incapability to differentiate between pathological and
physiological changes. Thus, new biomarkers with improved diagnostic
accuracy are needed. Our aim was to develop and validate a novel assay
for skeletal troponin I (skTnI), and to assess its clinical performance
in patients with idiopathic inflammatory myopathies (IIM).Methods:A two-step fluoroimmunoassay was used to analyze samples from healthy reference individuals (n = 140), patients with trauma (n = 151), and patients with IIM (n = 61).Results:The
limit of detection was 1.2 ng/mL, and the upper reference limit (90th
percentile) was 5.2 ng/mL. The median skTnI concentrations were
P < 0.001; Mann–Whitney P < 0.001 for all). skTnI and CK had a strong positive correlation (Spearman’s r = 0.771, P < 0.001), and the longitudinal changes in skTnI mirrored those observed with CK.Conclusions:With
the skTnI assay, patients with IIM were identified from healthy
individuals and from patients with traumatic muscular injuries. When
compared to CK, skTnI appeared to be more accurate in managing patients
with low-grade IIM disease activities. The developed assay serves as a
reliable analytical tool for the assessment of diagnostic accuracy of
skTnI in the diagnosis and monitoring of myopathies.
Background:The
current biomarkers for diagnosis and monitoring of injured and diseased
skeletal muscles, such as creatine kinase (CK), have limited tissue
specificity and incapability to differentiate between pathological and
physiological changes. Thus, new biomarkers with improved diagnostic
accuracy are needed. Our aim was to develop and validate a novel assay
for skeletal troponin I (skTnI), and to assess its clinical performance
in patients with idiopathic inflammatory myopathies (IIM).Methods:A two-step fluoroimmunoassay was used to analyze samples from healthy reference individuals (n = 140), patients with trauma (n = 151), and patients with IIM (n = 61).Results:The
limit of detection was 1.2 ng/mL, and the upper reference limit (90th
percentile) was 5.2 ng/mL. The median skTnI concentrations were
P < 0.001; Mann–Whitney P < 0.001 for all). skTnI and CK had a strong positive correlation (Spearman’s r = 0.771, P < 0.001), and the longitudinal changes in skTnI mirrored those observed with CK.Conclusions:With
the skTnI assay, patients with IIM were identified from healthy
individuals and from patients with traumatic muscular injuries. When
compared to CK, skTnI appeared to be more accurate in managing patients
with low-grade IIM disease activities. The developed assay serves as a
reliable analytical tool for the assessment of diagnostic accuracy of
skTnI in the diagnosis and monitoring of myopathies.
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