Cord blood house dust mite allergen in newborns: relationship to maternal blood levels of allergen and allergen specific IgG and IgE.

BACKGROUND: House dust mite allergen has previously been detected in the cord blood of some newborns but not others. The factors that affect the presence and levels in cord blood of this and possibly other allergens are unknown. OBJECTIVE: To test the hypothesis that the levels of maternal allergen and allergen specific IgG affect the presence and levels of newborn allergen. METHODS: Enzyme-linked immunosorbent assays were used to measure the levels of house dust mite allergen Der p 1 and Der p 1 specific IgG and IgE in paired blood samples from 98 mothers and full-term newborns. RESULTS: Der p 1 was detected in 27 mothers and 12 newborns. None of the 71 mothers who lacked Der p 1 had Der p 1-positive newborns. When present, cord blood Der p 1 levels correlated with and were approximately one third of Der p 1 levels in maternal blood. Cord blood Der p 1 levels also tended to correlate with maternal blood levels of Der p 1 specific IgG but showed little, if any, correlation with maternal blood levels of Der p 1 specific IgE. CONCLUSIONS: When detectable, the levels of an allergen in the blood of newborns correlate with the levels of that allergen in the blood of their mothers and tend to be related to maternal levels of allergen specific IgG.