Performance Characteristics - AIDIAN go CRP Manual Del Usuario

QuikRead CRP Controls: All QuikRead CRP controls are ready-to-use. The control value
has been determined for the QuikRead go instrument with the same instructions for use as
for plasma/serum samples. The sample volume is 20 μl. If you want to use sample volume
12 µl, you have to change the setting of the QuikRead go instrument. See Instrument
manual: Settings → Measurement flow → Test parameters.
Other commercially available CRP controls: Handle and use according to the instructions
for each control substance. Acceptable limits for the control must be defined with precision
results gained with the QuikRead go instrument. The blanking process might not succeed if
you use a control that contains artificial red blood cells.
9 Results' interpretation
Elevation of CRP value is unspecific and the results should be interpreted in the light of
other clinical findings.
CRP test result
< 10 mg/l
10–50 mg/l
> 50 mg/l
10 Limitations of the procedure
Assay procedures other than those specified in these instructions may yield questionable
results. Some substances may interfere with the test results; please see Section 12.

"Performance Characteristics".

Test results should never be used alone, without a complete clinical evaluation, when making
a diagnosis. Intra-individual variations in CRP are significant and should be taken into account
– for example, by means of serial measurements – when interpreting the values.
11 Expected values
The assay reference range limit was determined by using 143 apparently healthy adults
(59 males and 84 females) with age 19–65 according to CLSI EP28-A3C guideline. Based
on the results the 95% reference limit was concluded to be ≤ 5 mg/l for each sample type.
Results are based on a non parametric approach.
However, each laboratory is recommended to establish a range of normal values for their
population in their region.
12 Performance characteristics
Method comparison
Patient plasma samples were measured using two clinical laboratory methods, and the
QuikRead go CRP method. Summary of correlation studies is presented in the table below.
Clinical laboratory method 1
y =
r =
n =
Whole blood versus plasma comparability
In a comparison of 104 patient samples, whole blood (y) and plasma (x) were found
comparable. y = 1.03x – 0.3
Precision
A precision study was performed according to Clinical and Laboratory Standards Institute
(CLSI) guideline EP5-A2.
Sample Sample
material number
Sample 1
Whole blood Sample 2
Sample 3
Sample 1
Plasma Sample 2
Sample 3
Control Sample 1
Measuring range
For whole blood samples the measuring range is 5–200 mg/l at the normal hematocrit level
of 40%. If the hematocrit is lower or higher than 40%, the measuring range will change
according to the table below. Starting from QuikRead go instrument software version 3.1,
the instrument displays a CRP result at hematocrit range of 15–75%. Previous instrument
software versions display CRP results at hematocrit range of 20–60%. The CRP result is not
displayed, if the level of hematocrit is outside the range of 15–75% or 20–60% (depending
on the instrument software version).
Sample type Hematocrit % Sample volume Measuring range mg/l CRP
Whole blood
sample
Plasma/
Serum sample
Interference
Interferent
Bilirubin
Vitamin C
Triglycerides
Cholesterol
Rheumatoid factors (RF)
Leucocytes
Anticoagulants (Li-heparin or EDTA)
Interpretation of result
Excludes many acute inflammatory diseases, but does not specifically
exclude inflammatory processes.
Elevated concentrations found in acute disease that occur in the presence
of a slight to moderate inflammatory process.
Indicates high and extensive inflammatory activity.
Passing-Bablok analysis
1.00x + 1.0
0.994
116
Within-run, between-day and total precision
Number
of days
20
20
20
20
20
20
20
15–19
20–28
29–35
36–41
42–46
47–50
51–53
54–56
57–60
61–62
63–64
65–66
67–68
69–70
71–72
73–74
75
–
7
Clinical laboratory method 2
Mean CRP Within-run
(mg/l) CV (%)
9
52
177
10
55
148
30
20 µl
20 µl
12 µl
No interference found up to concentration
400 µmol/l
200 µmol/l
11.5 mmol/l
9.0 mmol/l
525 IU/ml
145x10 cells
9
No interference
y = 0.93x + 1.4
r = 0.987
n = 113
Between-day
CV (%)
4.5 4.3
1.4 2.4
1.9 2.8
3.7 0.1
1.5 0.4
2.0 1.0
2.0 3.1
5–150
5–160
5–180
5–200
5–220
5–240
5–260
5–280
5–300
5–330
5–340
5–360
5–390
5–410
5–440
5–470
5–510
5–120
5–200
Total
CV (%)
6.2
3.2
3.6
4.2
1.9
2.4
3.7
In cases when
the result is
above or below
the measuring
range, the
result will be
displayed,
for example
"> 200 mg/l
CRP".