The glycosphingolipid composition of the placenta of a blood group P fetus delivered by a blood group Pk1 woman and analysis of the anti-globoside antibodies found in maternal serum.
To further define the molecules that may mediate spontaneous abortion due to maternal-fetal blood group incompatibility within the P blood group system, we have examined the fine specificities of maternal antibodies and the glycolipid antigens from the placenta of a P infant born to a Pk1 mother. Maternal antibodies obtained during therapeutic plasmapheresis were analyzed to determine their reactivities with placental glycolipid extracts on thin-layer plates. Second antibodies specific for IgM, IgG, and IgA revealed immunoglobulins of all of these classes strongly reactive with one major placental glycolipid that comigrates with globoside. GC/MS analysis confirmed that the major P-active pentaglycosylceramide of placenta has the same structure as that previously shown for the P antigen of red blood cells: GalNAc beta 1-3Gal alpha 1-4Gal beta 1-4Glc-Cer. Serum antibodies partially purified by affinity chromatography on globoside-octyl-Sepharose specifically recognize glycolipids that contain terminal GalNAc beta 1-3Gal . . . residues and also recognize the same sequence as an internal determinant in some, but not all, glycolipids with extended globoside core regions. Thus, in the blood group P incompatible fetus, the major P antigen present in placenta has the same carbohydrate structure as the P antigen present in fetal and adult erythrocytes and might be a target for the maternal immune system.
Hansson
G C
GC
Laboratory of Pathology, National Cancer Institute, Bethesda, Maryland 20892.
Wazniowska
K
K
Rock
J A
JA
Ness
P M
PM
Kickler
T S
TS
Shirey
R S
RS
Niebyl
J R
JR
Zopf
D
D
D000328:Adult; D000918:Antibody Specificity; D000937:Antigen-Antibody Reactions; D001787:Blood Group Incompatibility / Q000276:immunology*; D005260:Female; D005915:Globosides / Q000276:immunology*; D006028:Glycosphingolipids / Q000032:analysis* / Q000276:immunology*; D006801:Humans; D007518:Isoantibodies / Q000032:analysis*; D010920:Placenta / Q000032:analysis* / Q000276:immunology; D011247:Pregnancy; D011250:Pregnancy Complications, Hematologic / Q000276:immunology
D005915:Globosides; D006028:Glycosphingolipids; D007518:Isoantibodies