A Three-Site Immunoassay for High-Sensitivity Cardiac Troponin I with Low Immunoreactivity for Macrocomplexes
Key result
The 3-site Ortho hs-cTnI assay demonstrated significantly lower immunoreactivity to macrocomplexes compared with the Abbott hs-cTnI assay in three patients with suspected macrocomplex interference.
Why the study?
Macrocomplexes can cause discrepant hs-cTn concentrations, and whether 3-site immunoassays consistently yield higher immunoreactivity for macro-cTnI remained contradictory.
Does the Ortho 3-site hs-cTnI immunoassay have lower immunoreactivity to macrocomplexes compared to other hs-cTnI assays in patients with suspected falsely elevated troponin?
Population
3 patients with suspected macrocomplexes as a source of high hs-cTnI by Abbott assay
Comparison
Ortho hs-cTnI assay vs Abbott hs-cTnI and Siemens Dimension EXL assays
Design
Case series
Authors
Discussion
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Member takes
Implication
May aid resolution of suspected macro troponin false positives; hypothesis-generating and requires prospective validation.
Study Design
Type
Case Report (n=3)
Structured PICO
Does the Ortho 3-site hs-cTnI immunoassay have lower immunoreactivity to macrocomplexes compared to other hs-cTnI assays in patients with suspected falsely elevated troponin?
P
Population
3 women (ages 48-76) with suspected macrocomplex interference causing elevated hs-cTnI concentrations on the Abbott assay.
E
Exposure
Measurement of hs-cTnI using the Ortho VITROS 3-site immunoassay
C
Comparator
Measurement using the Abbott 2-site hs-cTnI assay and Siemens Dimension EXL 3-site hs-cTnI assay
O
Outcome
hs-cTnI concentration and recovery after polyethylene glycol (PEG) precipitationsurrogate
The Ortho 3-site hs-cTnI assay may have lower immunoreactivity to macrocomplexes compared to other assays, which can help resolve clinical dilemmas of falsely elevated troponin.
Limitations
- The heterogeneity of these complexes is likely to be very large, making generalizations difficult.
- Additional studies using other methodologies for depleting immunoglobulins and biochemically characterizing these complexes are required.
- Heterogeneity of macrocomplexes is likely to be very large, making generalizations difficult
- Additional studies using other methodologies for depleting immunoglobulins and biochemically characterizing these complexes are required
Cite This Study
Kavsak et al. (2020) conducted a case report in Suspected macrocomplex interference in hs-cTnI assays (n=3). Ortho hs-cTnI assay vs. Abbott hs-cTnI assay was evaluated on hs-cTnI concentration and recovery after PEG precipitation. The 3-site Ortho hs-cTnI assay demonstrated significantly lower immunoreactivity to macrocomplexes compared with the Abbott hs-cTnI assay in three patients with suspected macrocomplex interference.