Human Troponin-I 2.0
205
SUMMARY AND EXPLANATION OF THE TEST
Cardiac Troponin-I (cTnI) is a 23.8 kD regulatory subunit of the troponin complex that is associated with the actin thin filament within cardiac muscle cells. The
troponin complex is composed of troponin-C and troponin-T, and it plays an integral role in the regulation of cardiac muscle contraction. Extensive clinical studies
have demonstrated that cTnI is slowly released into the blood within hours of myocardial infarction (MI) or ischemic damage. cTnI elevation is detectable in serum
within 4-6 hours after the onset of chest pain, and can remain elevated for up to 10 days following MI. cTnI measurements are highly specific for myocardial
damage, and can be useful for identifying cardiac injury from different sources, including surgery, trauma, and intensive exercise. Clinical studies have also shown
the patients with acute coronary syndromes (ACS) were at greater risk of progressing to MI if cTnI is elevated relative to an upper reference limit for healthy
individuals. This has spurred increasing attention in recent years on high sensitivity cTnI measurement. Potential benefits include more rapid diagnosis in ACS,
population screening, prognostic information in stable patients, and clinical drug development.
AEB
%CVdose
Troponin-I, pg/mL
Healthy donors
Troponin-I, pg/mL
Troponin-I, pg/mL
Figure 1: SimoaTM Troponin-I immunoassay
calibration curve. Four-parameter curve fit
parameters are depicted.
Figure 2: Troponin-I CV profile. Diluted serum
samples were assayed in reps of 3 over multiple days
and instruments (16 runs, 144 determinations). 95%
confidence intervals (CI) are depicted.
Median [TnI]
0.646 pg/mL
Median [TnI]
0.647 pg/mL
EDTA plasma
Serum
Figure 3: Troponin-I in EDTA plasma (n = 28)
and serum (n = 38). Error bars depict mean and
SEM. Troponin-I was measurable in all samples
tested.
Table 1: General characteristics of Simoa Human Troponin-I immunoassay
Calibration range
0-300 pg/mL
Dynamic range1
0-1200 pg/mL
Lower limit of detection (2.5 SD; 3 reps x 24 estimates across 12 runs, 3 instruments, 2 lots; mean LoD2)
0.013 pg/mL
Lower limit of quantification (≤20% CVdose at 95% CI see Figure 2)3
0.079 pg/mL
Lower limit of quantification (‘Fit for purpose’, 12 runs, 3 instruments, 2 reagent lots)4
Spike-recovery (cTnI spiked into 24 serum samples at 0.5, 5, and 50 pg/mL ,
0.075 pg/mL
80.5%
mean5)
Linearity (High cTnI serum sample admixed with low TnI sample, mean of 10 levels)
85.9%
Dilution linearity (2 to 16-fold serial dilution of serum with Sample Diluent, mean of 3 exps6)
89.5%
Endogenous interferences (Bilirubin, hemoglobin, protein, triglycerides,7 mean of 6 samples)
<20%
Inter lot CV (Pool of CVs from 9
9.3%
samples8
tested with 3 reagent lots across 2 runs x 3 instruments)
Inter instrument CV (Pool of CVs from 7 samples8 tested with 3 instruments across 2 runs x 2 reagent lots)
6.7%
Typical sample volume (Includes dead volume; see Package Insert for details)
49.5 µL
Total assay run time
45 min
auto-diluted 4X. 2SD 0.0103 pg/mL; range 0.003-0.044 pg/mL. 3Not corrected for pre-dilutions; 4X LLoQ 0.316 pg/mL. 4≤20% CV, 80-120% recovery; pooled CV 18.3%, mean recovery 98.6%
not corrected for pre-dilutions; 4X LLoQ 0.300 pg/mL. 5Range 64.1 -103.7%. 6Range of means at each dilution: 82.0-100.67%. 720 mg/dL, 500 mg/dL, 12 g/dL, and 1000 mg/dL, respectively.
8Range 1.08-185 pg/mL.
1Samples
Representative data. Individual results may vary depending upon samples tested and protocols followed.
Assay designed by Purvish
The Simoa Human
Troponin-I immunoassay
reliably quantifies
Troponin-I in serum and
plasma in healthy subjects,
with median Troponin-I
values well above the
sensitivity limits.
Simoa
Reagent Kit
For Research Use Only. Not for use in diagnostic procedures.
USER-205-02 14JAN2016
Human Troponin-I 2.0
Page 2
205
Troponin-I , pg/mL
Troponin-I , pg/mL
REPRODUCIBILITY AND REPEATABILITY CHARACTERISTICS OF THE TEST
Mean Troponin-I, pg/mL
Mean Troponin-I, pg/mL
Figure 4:
Reproducibility across lots. Nine native and spiked serum
and plasma troponin-I samples tested across 2 runs x 3 instruments each
lot. Data points depict means for each sample. Regression statistics
reflect linear analysis.
Figure 5:
Reproducibility across instruments. Seven native and
spiked serum and plasma troponin-I samples tested across 2 runs x 2
reagent lots each instrument. Data points depict means for each
sample. Regression statistics reflect linear analysis.
Table 2: Reproducibility precision of Simoa Human Troponin-I 2.0 immunoassay across instruments and reagent lots.
Reproducibility was determined with guidance from CLSI Protocol EP5-A. Six samples consisting of four serum panels and two troponin-I
controls were assayed in replicates of three for two runs on each of three instruments and two reagent lots. Analysis of variance (nested
ANOVA) results are summarized in the following table.
Sample
Mean
Troponin-I
(pg/mL)
Within Run
Between Run
Between Lot
%CV, n=36
%CV, n=12
%CV, n=2
Between
Instrument
%CV, n=3
Control 1
Control 2
3.25
160
7.7
4.7
7.6
8.3
0.0
9.4
4.3
0.0
Panel 1
Panel 2
Panel 3
Panel 4
1.11
2.79
5.61
37.5
9.9
11.3
4.5
4.0
4.3
0.0
7.0
7.7
2.3
7.4
4.4
0.0
2.2
0.0
0.0
0.0
Panel 5
109
4.5
12.3
0.0
1.1
Table 3: Repeatability precision of Simoa Human Troponin-I immunoassay. Repeatability was determined in a
separate study from Table 2 with guidance from CLSI Protocol EP5-A. Five samples consisting of two serum-based panels, one
plasma-based panel, and two troponin-I controls were assayed in replicates of three at two separate times per day for five days
using a single stored calibration curve and a single lot of reagents. Analysis of variance (fully nested ANOVA) results are
summarized in the following table.
Sample
Mean
Troponin-I
(pg/mL)
Control 1
Control 2
Panel 1
Panel 2
Panel 3
2.55
115
2.04
5.73
54.4
Within Run
Between Run
Between Day
%CV (n=30)
%CV (n=10)
%CV (n=5)
7.6
5.4
9.7
5.9
4.8
5.1
8.1
3.0
0.0
3.8
7.2
9.7
0.0
1.0
1.8
Representative data. Individual results may vary depending upon samples tested and protocols followed.
Assay designed by Purvish
Simoa
HD-1 Analyzer
For Research Use Only. Not for use in diagnostic procedures.
USER-205-02
13JAN2016