Naslov
Total human chorionic gonadotropin versus free beta-subunit in fetal aneuploidy screening

Autori
Huderer-Đurić, Koraljka ; Mitić, V. ; Tišlarić, Dubravka ; Petek, Marijan ; Suchanek, Ernest

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Biochemia Medica / Suchanek Ernest - Zagreb : Hrvatsko društvo za medicinsku biokemiju i laboratorijsku medicinu (HDMBLM), 2000

Skup
6th Alps-Adria Congress of Clinical Chemistry and laboratory Medicine

Mjesto i datum
Opatija, Hrvatska, 15.06.2000. - 17.06.2000

Vrsta sudjelovanja
Poster

Vrsta recenzije
Nije recenziran

Ključne riječi
Total hCG; free beta-hCG

Sažetak
The levels of intact chorionic gonadotropin and its free beta subunits are eleveted in maternal serum of pregnancies with trisomy 21, and lower in trisomy 18 or 13. The objective was to evaluate the usefulness of total chorionic gonadotropin (ThCG) and free beta-subunit (free beta hCG) in non-invasive detection of fetal aneuploidy. In 213 women aged >/=35 years blood samples were taken in 16th-20th gestational weeks and prenatal karyotyping was performed. Eleven caes of trisomy 21, three of Edwards syndrome, two of trisomy 13 and one mosaic trisomy 9 were studied. 196 samples from patients with euploid karyotype and normal pregnancy outcomes were selected as controls to calculate gestational week-specific medians. The assay for ThCG was specific for nicked and non-nicked free beta-subunits.. Raw analyte values were corrected for maternal weight and converted in multiples of the controls' medians (MoM). For certain decision level, the sensitivity of the marker was the percentage of trisomy cases successfully detected while false positive rate was the percentage of unaffected cases that were screen-positive. The unaffected medians of free beta-hCG raw values (IU/L) were 8.55, 8.29, 7.5, 5.97, 4.49 and for ThCG (kIU/L): 50.5, 40.6, 37.9, 29.4, 31.4. The medians of free beta-hCG MoMs were 1.0 in euploid, 1.9 in trisomy 21, and 0.6 in pregnancies with trisomies other than Down's syndrome. Significant differences were found between Down's syndrome and other trisomies (p<0, 001) and in their relation to euploid pregnancies (p<0, 05). For ThCG, medians of the MoMs were 1.01 in euploid pregnancies, 1.32 in trisomy 21, and 0.7 in trisomies other than Down's syndrome. Significant was only difference between Down's syndrome and other trisomies (p<0, 05). Considering cut-off MoM >/=2, 0, sensitivity for Down's syndrome was 45, 5% (5/11) for free beta-hCG and 9, 1% for ThCG, with false-positive rate 17, 3% (34/196) and 14, 3% (28/196), recpectively. When comparing pregnancies with trisomies other than Down's syndrome to euploid ones, sensitivity and false-positive rate with cut-off MoM </=0, 8 were 83, 3% (5/6) and 39, 3% (77/196) for free beta-hCG, and 50% (3/6) and 38, 8% (76/196) for ThCG. Free beta-hCG allowed classification of patients into normal and trisomic groups more correctly than ThCG. Thus, the results support the superior usefulness of free beta-hCG) in biochemical screening.

Izvorni jezik
Engleski

Znanstvena područja
Kliničke medicinske znanosti

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