Studies on the elevated amniotic fluid SP1 in Meckel's syndrome: modified glycosylation of SP1.
Pregnancy-specific beta 1-glycoprotein (Schwangerschaftsprotein, SP1) is elevated in the amniotic fluid in Meckel's syndrome. In an attempt to clarify this phenomenon, we studied fetal tissues by immunohistochemistry for the distribution of SP1 in normal fetuses and fetuses with Meckel's syndrome. The amount of SP1 was increased in two out of ten Meckel placentae, as semiquantitatively shown by the immunoperoxidase method, but was normal in the rest of the cases. There was no difference in the SP1 distribution or content in the other fetal tissues studied. Fetal cerebrospinal fluid contained only very low levels of SP1 and thus cannot provide a source for elevated amniotic fluid SP1. In addition, binding of amniotic fluid SP1 to concanavalin A (Con-A) was studied in pregnancies with normal fetuses and Meckel's syndrome using affinity chromatography. The proportion not bound to Con-A in normal amniotic fluids decreased with advancing gestation and was lowest when the total SP1 concentrations were highest. An especially low percentage of SP1 not bound to Con A was found in Meckel's syndrome, suggesting an altered carbohydrate structure of SP1 in these amniotic fluids.
Heikinheimo
M
M
Department of Bacteriology and Immunology, Children's Hospital, Helsinki, Finland.
Jalanko
H
H
Renlund
M
M
Rapola
J
J
Wahlström
T
T
D000653:Amniotic Fluid / Q000032:analysis*; D002847:Chromatography, Agarose; D003208:Concanavalin A; D005260:Female; D005333:Fetus / Q000378:metabolism; D006031:Glycosylation; D006801:Humans; D007124:Immunoenzyme Techniques; D007231:Infant, Newborn; D010920:Placenta / Q000378:metabolism; D011247:Pregnancy; D011257:Pregnancy Proteins / Q000378:metabolism*; D011268:Pregnancy-Specific beta 1-Glycoproteins / Q000134:cerebrospinal fluid / Q000378:metabolism*
D011257:Pregnancy Proteins; D011268:Pregnancy-Specific beta 1-Glycoproteins; D003208:Concanavalin A