THE DIAGNOSTIC SIGNIFICANCE OF CONCANAVALIN A REACTIVITY PATTERN OF HUMAN ALPHA-FETOPROTEIN IN AMNIOTIC FLUID

1981 ◽  
pp. 293-302
Author(s):  
K. Toftager-Larsen ◽  
B. Norgaard-Pedersen
Keyword(s):  
Amniotic Fluid ◽  
Concanavalin A ◽  
Alpha Fetoprotein ◽  
Reactivity Pattern ◽  
Diagnostic Significance

Reactivity of amniotic fluid alpha-fetoprotein with concanavalin A in relation to gestational age: clinical implications.

1980 ◽  
Vol 26 (12) ◽  
pp. 1656-1659 ◽  
Author(s):  
K Toftager-Larsen ◽  
E Kjaersgaard ◽  
J C Jacobsen ◽  
B Nørgaard-Pedersen
Keyword(s):  
Amniotic Fluid ◽  
Clinical Significance ◽  
Concanavalin A ◽  
Gestational Age ◽  
Normal Values ◽  
Alpha Fetoprotein ◽  
Clinical Implications ◽  
Fetal Malformation ◽  
Average Decrease ◽  
Normal Outcome

Abstract We used concanavalin A crossed-line affinity immunoelectrophoresis to determine the percentage of concanavalin A nonreactive alpha-fetoprotein in amniotic fluid samples from pregnancies with normal and abnormal fetuses. In 167 samples from pregnancies with a normal outcome and normal values for total alpha-fetoprotein concentration in amniotic fluid the percentage decreased from a median value of 27.4% in the 13th week to 8.5% in the 21st week of gestation, and a statistically significant (p < 0.001) average decrease of 1.7% per week was found from the 14th to the 19th week. A similar average decrease (2.2%) was found in 22 pregnancies from which two or more samples were obtained. The clinical significance of this decrease is discussed. Of 108 samples from patients with above-normal values for total alpha-fetoprotein and a normal outcome, seven had a total alpha-fetoprotein above recommended cut-off values, and only one of these had a low percentage of concanavalin A nonreactive alpha-fetoprotein. In contrast, for all 27 samples from pregnancies with a severe fetal malformation this percentage was low, even in one case where the total alpha-fetoprotein concentration was below the recommended cut-off value.

Concanavalin A binding of alpha-fetoprotein in amniotic fluid as an aid in the diagnosis of neural tube defects.

1981 ◽  
Vol 27 (10) ◽  
pp. 1658-1660 ◽  
Author(s):  
P K Buamah ◽  
P Taylor ◽  
A M Ward
Keyword(s):  
Spina Bifida ◽  
Amniotic Fluid ◽  
Neural Tube ◽  
Neural Tube Defects ◽  
Concanavalin A ◽  
Gestational Age ◽  
Alpha Fetoprotein ◽  
Normal Outcome ◽  
Fetal Malformations ◽  
Open Spina Bifida

Abstract Concanavalin A nonreactive alpha-fetoprotein was determined in samples of amniotic fluid from 16 abnormal pregnancies complicated by anencephaly (7), open spina bifida (6), intra-uterine death (1), anencephaly with exomphalos (1), or open spina bifida with exomphalos (1), and in amniotic fluid from 50 normal pregnancies with gestational age between 13 and 24 weeks. In all 16 cases with fetal malformations, the proportion of nonreactive alpha-fetoprotein was significantly decreased (median 5.3%) as compared with amniotic fluid from pregnancies with a normal outcome (median 39.7%). The results confirm that this measurement is useful in the diagnosis of neural tube defects, especially when the concentration of alpha-fetoprotein in amniotic fluid is normal or only slightly above normal and gestational age is uncertain.

CONCANAVALIN-A REACTIVITY OF AMNIOTIC FLUID ALPHA-FETOPROTEIN IN DIAGNOSIS OF NEURAL-TUBE DEFECTS

The Lancet ◽  
1979 ◽  
Vol 314 (8148) ◽  
pp. 906 ◽  
Author(s):  
P. Hindersson ◽  
K. Toftager-Larsen ◽  
B. Nørgaard-Pedersen
Keyword(s):  
Amniotic Fluid ◽  
Neural Tube ◽  
Neural Tube Defects ◽  
Concanavalin A ◽  
Alpha Fetoprotein

Comparison of amniotic fluid alpha-fetoprotein reactivity to Lens culinaris agglutinin and concanavalin A in crossed-affinity immunoelectrophoresis: ancillary tests in the prenatal diagnosis of severe fetal malformations.

1983 ◽  
Vol 29 (1) ◽  
pp. 21-24 ◽  
Author(s):  
K Toftager-Larsen ◽  
E Kjaersgaard ◽  
B Nørgaard-Pedersen
Keyword(s):  
Prenatal Diagnosis ◽  
Amniotic Fluid ◽  
Neural Tube ◽  
Neural Tube Defects ◽  
Concanavalin A ◽  
Lens Culinaris ◽  
Alpha Fetoprotein ◽  
Fetal Abnormality ◽  
Lens Culinaris Agglutinin ◽  
Ancillary Test

Abstract Crossed-affinity immunoelectrophoresis of alpha-fetoprotein in amniotic fluid from 135 normal and 39 abnormal pregnancies (mainly neural-tube defects) was performed with a lectin, agglutinin from Lens culinaris. Results were compared with findings reported for another lectin, concanavalin A. Three fractions of alpha-fetoprotein were obtained by reaction with Lens culinaris agglutinin. The most weakly reactive fraction correlated strongly with the concanavalin A nonreactive fraction. With both lectins, significantly lower concentrations of these fractions were found in all samples from abnormal pregnancies than in those from normal pregnancies. In eight cases with a fetal abnormality the total alpha-fetoprotein concentrations were below the lower limit for abnormal samples. All eight samples revealed fractions weakly reactive with Lens culinaris agglutinin below the lower 0.1% limit for normal samples; seven of these samples had fractions nonreactive with concanavalin A below this limit. Although a decrease in the two described fractions in normal pregnancies was found with increasing gestational age, we find either method to be valuable as an ancillary test in the prenatal diagnosis of fetal neural-tube defects and other malformations.

scholarly journals Amniotic fluid alpha-fetoprotein and congenital hydrocephalus.

BMJ ◽  
1976 ◽  
Vol 2 (6049) ◽  
pp. 1450-1450 ◽  
Author(s):  
E M Williamson ◽  
D C Siggers ◽  
J F Miller
Keyword(s):  
Amniotic Fluid ◽  
Alpha Fetoprotein ◽  
Congenital Hydrocephalus
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