Helicobacter pylori-specific immune response in maternal serum, cord blood, and human milk among mothers with and without current Helicobacter pylori infection.

We assessed the patterns of Helicobacter pylori (H. pylori) specific maternal antibodies in maternal serum, cord blood, and milk, which might play a role in prevention of H. pylori infection because transferred to the infant. Between November 2000 and November 2001, mothers were recruited after delivery of their offspring. H. pylori infection status was determined by 13C-urea breath test (UBT). Specific H. pylori antibody profiles were analysed using commercial H. pylori-specific enzyme-linked immunosorbent assay and Western blots. Among 898 mothers, 23% had a current H. pylori infection. Median H. pylori IgG antibody titers in serum and cord blood of UBT-positive mothers were 23.8 U/mL and 24.0 U/mL, respectively. Whereas prevalences of H. pylori-specific antibodies in serum of UBT-negative mothers were clearly lower than those among UBT-positive mothers, patterns of H. pylori-specific IgA antibodies in milk were similar among UBT-positive and UBT-negative mothers. Neonates born from H. pylori-infected women are provided with large amounts of transplacentally transferred specific IgG H. pylori antibodies. Breast-fed neonates are additionally provided with specific IgA antibodies in human milk. Notably, the latter may also be activated if exposure of the mother to H. pylori might have been long time ago and been cleared in the meantime.