Performance Characteristics - Actim Partus 1ngeni Notice D'utilisation

• If the procedural control line is not detected by the Actim 1ngeni instrument,
the result will be declared indeterminate and the test should be repeated.
• The result must not be visually inspected after analysing it with the
instrument.
• Do not re-analyse a test with the instrument.
• For additional information, please refer to the Actim 1ngeni instrument
manual.
• As with all diagnostic tests, results must be interpreted in the light of other
clinical findings.
• All biological specimens and materials must be treated as potentially
hazardous, and disposed of in accordance with local authority guidelines.
Principle of the test
Decidual cells synthesize the phosphorylated forms of IGFBP-1 (phIGFBP-1)
while amniotic fluid contains substantial quantities of non- and less
phosphorylated forms of IGFBP-1. When delivery is approaching, fetal
membranes begin to detach from the decidua parietalis, and small amounts of
phIGFBP-1 begin to leak into cervical secretions. In Actim Partus 1ngeni test a
cervical specimen sample is taken with a sterile polyester swab during sterile
speculum examination and extracted into the Specimen Extraction Solution.
The quantity of phIGFBP-1 in the solution is detected using a dipstick and Actim
1ngeni instrument.
The test is based on immunochromatography. It uses two monoclonal antibodies
to human IGFBP-1. One is bound to blue latex particles (the detecting label). The
other is immobilized on a carrier membrane to catch the complex of antigen
and latex-labeled antibody and indicate a positive result. When the dip area of
the dipstick is placed in an extracted sample, the dipstick absorbs liquid, which
starts to flow up the dipstick. If the sample contains phIGFBP-1 it binds to the
antibody labeled with latex particles. The particles are carried by the liquid flow
and, if phIGFBP-1 is bound to them, they bind to the catching antibody. A blue line
(test line) will appear in the result area if the concentration of phIGFBP-1 in the
sample exceeds the detection limit of the test. A second blue line (control line)
confirms correct performance of the test. The lines are read, and intensity of
line color is quantitated with Actim 1ngeni instrument.

Performance characteristics

Clinical performance study 1
The clinical performance of the Actim Partus 1ngeni test was evaluated in a
retrospective study using specimens obtained from pregnant women with
symptoms of preterm delivery (n=58; GA 22-42 weeks) and controls (n=62; GA
22-42 weeks).
Assessment of quantitative test results was made using delivery within 7
days as an end point. Comparison was also made to the cervical length. The
concentration of phIGFBP-1 was higher in those women, who delivered within 7
days after sample collection. Also, cervical canal was shorter in those patients.
Statistical analysis is shown in Table. 1 on the inner back cover. Correlation
between clinical outcome and concentration of phIGFBP-1, cervical length
and the combination of these are statistically significant (p-value ≤ 0.05) when
delivery occurs within 7 days (Table. 1).
Clinical performance study 2
The clinical performance of the quantitative Actim Partus 1ngeni was
assessed for pregnant women with signs and symptoms of preterm labor. This
retrospective study included 691 samples obtained from symptomatic women
(GA 22-35) with singleton pregnancies. From this group 360 woman delivered
spontaneously.
The clinical performance and statistical analyses showed, that the increasing
concentration of phIGFBP-1 correlated with increased relative risk of
delivery within 7 and 14 days from sample collection. Similarly, an increasing
concentration of phIGFBP-1 correlated with increased risk of spontaneous labor
and preterm birth before 30, 34 and 37 weeks of gestation. These findings and
their statistical significance are summarized in Table 2, 3, 4 and 5.
Analytical sensitivity
Analytical sensitivity (detectability) was tested with the quantitative Actim
Partus 1ngeni test. Negative samples as well as low level samples were used
for testing. The limit of blank, LoB, of the Actim Partus 1ngeni test was found to
be approximately 0.7 μg/l. The detection limit, LoD, of the quantitative Partus
test was found to be approximately 1.5 μg/l. The limit of quantification (LoQ) was
through precision study found to be approximately 3.5 μg/l.
Analytical specificity
Analytical specificity (cross-reactivity) was tested with human IGFBP proteins.
The IGF binding proteins -2, -4, -5 and -6 were tested at a concentration level of
5000 µg/l and IGF binding protein -3 at a concentration level of 50,000 µg/l. No
interference of the IGF binding proteins was observed with the performance of
Actim Partus 1ngeni test. The test is specific to human IGFBP-1.
Repeatability
A repeatability study was performed. Three panels of specimens were tested on
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