Abstract
Background: Maternal IgG antibodies can pass through the placental
barrier to the fetal circulation, and may sensitize fetal red cells when
there is maternal-fetal blood type incompatibility. The pathogenesis of
breast milk jaundice is not yet clear. Few studies have focused on
hemolytic disease of the newborn (HDN) associated with
passively-acquired maternal antibodies from breast milk, for which
individual cases were occasionally reported in recent years. Case
Report: Five newborns were found to develop jaundice 19 hours to 4 days
after birth. These affected neonates were enrolled in a study to test
free antibodies in plasma and antibodies bound to the surface of red
blood cells, as well as antibodies in their mothers’ blood and breast
milk. The data were analyzed in combination with the mothers’ antibody
monitoring records during pregnancy. Methods: 3 mL of
EDTA-anticoagulated venous blood was collected from each affected
neonate and 5 mL from his/her mother to separate plasma. The plasma was
incubated with panel cells in normal saline in test tubes at 37 °C for
45 min, and then added to anti-human globulin micro-column gel cards and
centrifuged to observe the results. 100–200 mL of the whey separated
from breast milk was used in a two-stage papain technique: 50 μL of
panel cells was incubated with 50 μL of 1% papain at 37 °C for 10 min,
then washed once with normal saline and prepared to a 3–5% cell
suspension; the cell suspension was incubated with 200–300 μL of whey
at 37 °C for 30 min, then washed 3 times with normal saline and prepared
to a 0.8–1% cell suspension. 50 μL of the resultant suspension was
added to anti-human globulin micro-column gel cards and centrifuged to
observe the results. In addition, an antibody elution test was conducted
on the red blood cells of the affected neonates. Results: The antibodies
in the red blood cell eluate of the affected neonates were consistent
with those in the maternal blood and breast milk. The antibodies
acquired in case 1 can immediately be considered irrelevant to the
placental route. Conclusion: Anti-erythrocyte IgG antibodies may result
from breast milk and cause red blood cell sensitization in newborns. For
children with severe HDN, restrictions on breastfeeding should be
considered to prevent continuous antibody acquisition.