Immunoglobulins and beta-1-C globulin in hydatidiform mole vesicles

Biochemical analyses of mesenchymal fluid in early pregnancy

OBJECTIVE

Our purpose was to compare the biochemical composition of the fluid contained in pathologic and physiologic cavities in early pregnancy.

STUDY DESIGN

The level of urea, creatinine, electrolytes, enzymes, total protein, and alpha-fetoprotein and the affinity of alpha-fetoprotein for concanavalin A Sepharose was measured in samples of vesicular fluid from complete (n=2) and partial (n=1) mole, nuchal fluid (n=4), and cystic hygroma fluid (n=4). For comparison samples of maternal serum (n=32), amniotic fluid (n=32), coelomic fluid (n=15), and fetal blood (n=13) were obtained from normal pregnancies at 10 to 16 weeks' gestation.

RESULTS

Urea concentration was lower, whereas sodium, potassium, and total protein concentrations were higher in vesicular fluid than in amniotic and coelomic fluid. Urea, creatinine, sodium, potassium, chloride, and beta2-microglobulin concentrations did not vary between nuchal or cystic hygroma fluid and amniotic fluid or fetal serum. The concentration of total protein in nuchal and hygroma fluid was significantly lower than in fetal serum and significantly higher than in amniotic fluid. The amniotic fluid contained extremely high tau-glutamyltransferase concentration compared with the other fluids and fetal serum. Alkaline phosphatase and amylase were not detectable in coelomic fluid, fetal serum, or nuchal and hygroma fluid. The nuchal and hygroma fluid composition was similar except for total protein and alpha-fetoprotein concentrations, which were significantly higher in nuchal than in hygroma fluid. The vesicular fluid from the partial mole, fetal serum, and nuchal and hygroma fluid contained extremely high alpha-fetoprotein concentrations, which were significantly higher that those found in amniotic fluid. In complete mole alpha-fetoprotein molecules were of the yolk sac type, whereas they were of the liver type in nuchal and hygroma fluid.

CONCLUSIONS

The composition of vesicular fluid in complete mole reflects a possible origin from the maternal plasma, yolk sac, and trophoblast, whereas the composition of nuchal and cystic hygroma fluid suggests a leakage from the fetal circulation.

Serum proteins in vesicular fluid of hydatidiform moles: a lack of selectivity of molar trophoblast in the transfer of maternal serum proteins

Complete hydatidiform moles, an abnormal pregnancy of androgenetic origin consisting of swollen villi without an embryo, were studied to determine the protein constitution of vesicular fluids in the swollen villi and the ability of the molar tissue to synthesize protein. All 16 serum proteins tested were identified in the molar fluid. A reverse correlation was obtained when the logarithms of the molar fluid versus maternal serum concentration ratios of different proteins were plotted against the logarithms of their molecular weights. Logarithmic regression analysis showed a linear regression with a high coefficient (gamma = 0.9626). Phenotyping of haptoglobin in the molar fluid and in the parental sera indicated a definite contribution of maternal proteins to the molar fluid. The molar tissues synthesized no serum proteins but produced human chorionic gonadotrophin beta-subunit (hCG-beta) and pregnancy-specific beta 1-glycoprotein (SP1) when examined in tissue cultures metabolically labelled with [35S]methionine. These findings indicate that a variety of maternal serum protein components is transferred to the molar fluid without being selected by the molar trophoblastic cells.