Passive Immunoprophylaxis for the Protection of the Mother and Her Baby: Insights from In Vivo Models of Antibody Transport

Figure 3

Maternal and fetal concentrations of human IgG following hepatitis B immune globulin (HBIG) administration at different gestation ages. HBIG was administered intravenously at a dose 100 IU/kg (~7 mg/kg) at different gestation ages in timed-pregnant guinea pigs and total human IgG concentrations ((a), (b), (e), and (f)), human IgG subclasses ((c), (d)), and neutralizing activity (anti-HBs, (e)) five days after administration were measured. Shown gestation days (GD, -axis, or legend) roughly correspond to the end of first trimester (GD26), middle and end of second trimester (GD35 and GD45), and middle and end of third trimester (GD55 and 65). Maternal total human IgG concentrations decreased (a) and the corresponding fetal concentrations increased (b) with gestation. Similar trends were seen for human IgG subclasses in the maternal (c) and fetal (d) samples as well as the anti-HBs neutralizing activity in the mother ((e), shaded bars) and fetus ((e), clear bars). The maternal and fetal total IgG concentrations were negatively correlated (f) and, after log transformation, the relationship was linear (dotted line, Pearson , ). Data shown as mean ± SEM; , , , and .

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(b)

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(f)