Transferrin microheterogeneity in fetal blood

Objectives: To investigate the distribution of microheterogeneous subfractions of transferrin in fetal blood and the influence of highly sialylated transferrins on fetal growth. Study Method: Serum transferrin concentrations were determined by a standard turbidimetric assay. Microheterogeneous transferrin subfractions were assessed by crossed immunoisoelectric focusing. Results: In normal term infants, total serum transferrin concentrations and percent distribution of highly sialylated transferrins (greater than or equal to5-sialo-transferrins) were markedly lower; the percent distributions of hyposialylated transferrins (0- and 1-sialo-transferrins) were apparently higher than those in non-pregnant and pregnant women. There was no significant positive correlation between the serum concentrations of total transferrin or highly sialylated transferrins in infants' blood and birth weights (r = 0.187, p = 0.582; r = 0.374, p = 0.257, respectively). Conclusion: The transferrin microheterogeneity pattern shifted towards reduced glycosylation and sialylation in addition to a decrease in total transferrin concentration in fetal blood compared to that of non-pregnant and pregnant women. The concentrations of serum total transferrin and the highly sialylated transferrins in fetal blood, if higher than a certain level, did not seem to have any influence on normal fetal growth. Copyright (C) 2004 S. Karger AG, Basel.