Siemens IMMULITE 2000 HCG Bedienungsanleitung Seite 4

such an early stage of pregnancy that the
HCG concentration has not yet reached
the decision level set for the procedure.
Assaying another sample collected two or
more days later should settle the matter,
since in early pregnancy HCG levels can
be expected to double in approximately
11
this time.
Interpretation of Results
A result of greater than or equal to
30 mIU/mL indicates that the patient
sample is positive for pregnancy.
A result of less than 30 mIU/mL indicates
that the patient sample is negative for
pregnancy.
Expected Values
Based on its relationship to IMMULITE HCG
(see Method Comparison), the assay can be
expected to have essentially the same
reference ranges.
Males and Nonpregnant Females
In a study performed with the IMMULITE
HCG assay and involving serum samples
from 797 adult volunteers, including 428
males and 369 nonpregnant females, 95%
of the results for males were below that
assay's detection limit (1.1 mIU/mL) and all
were below 2.5 mIU/mL, while 83% of the
results for nonpregnant females were below
the detection limit, 95% were below
2.7 mIU/mL, and all were below
5.3 mIU/mL. The subjects were in apparent
good health based on a questionnaire.
Pregnant Females
A total of 593 serum samples from
apparently healthy pregnant women were
processed by the IMMULITE HCG assay.
The results are summarized below
(in mIU/mL) by gestational age (Gest.) —
equivalently, by weeks since last menstrual
period (LMP). Also see "Expected Values
During Pregnancy" graph.
4
Weeks of Pregnancy
Gest. LMP n Median
1.3–2 3.3–4 30 71
2–3 4–5 54 607
3–4 5–6 34 5,243
4–5 6–7 34 26,983
5–6 7–8 36 52,090 23,100–151,000
6–7 8–9 33 93,598 27,300–233,000
7–11 9–13 116 117,678 20,900–291,000
11–16 13–18 72 40,989 6,140–103,000
16–21 18–23 80 20,868
21–39 23–41 104 15,352
Consider these limits as guidelines only.
Each laboratory should establish its own
reference ranges.
Pathological Conditions
Ectopic pregnancies or abnormal
intrauterine pregnancies have circulating
HCG levels below normal for that
gestational period; after an initial rise
3,17,18
these levels plateau or fall.
Limitations
The procedure for urine samples is
designed solely as a screen for
pregnancy, using a 30 mIU/mL cutoff.
Hence urinary results should be reported
in a strictly qualitative manner, e.g. as
"positive" or "negative" for pregnancy —
concentration values should not be
reported for this sample type.
Heterophilic antibodies in human serum
can react with the immunoglobulins
included in the assay components causing
interference with in vitro immunoassays.
[See Boscato LM, Stuart MC. Heterophilic
antibodies: a problem for all
immunoassays. Clin Chem 1988:34:27-
33.] Samples from patients routinely
exposed to animals or animal serum
products can demonstrate this type of
interference potentially causing an
anomalous result. These reagents have
been formulated to minimize the risk of
interference; however, potential
interactions between rare sera and test
components can occur. For diagnostic
purposes, the results obtained from this
assay should always be used in
combination with the clinical examination,
patient medical history, and other findings.
IMMULITE 2000 HCG (PIL2KCG-26, 2009-04-17)
Central 95%
16–156
101–4,870
1,110–31,500
2,560–82,300
4,720–80,100
2,700–78,100