Transplacental transmission of dust mite antigen

Abstract

Rationale Atopy and asthma is more prevalent in children of atopic mothers than atopic fathers, suggestive of additional maternal influence. Mothers might influence their infants' IgE responses by serving as a source of transplacentally transmitted allergens. Aim To detect transplacental transmission of dust mite antigen; to observe whether transmission is more likely in offspring of dust mite atopic vs non-atopic mothers. Methods 98 random paired maternal and cord blood samples (with precautions to prevent maternal blood contamination) were collected at delivery. Maternal serum was tested for anti-IgE for dust mite (Alastat Elisa, DPC) and dust mite antigen (DMAg) levels (Indoor Biotechnologies Inc). All the cord blood samples were tested for DMAg levels. Results 71/98 mothers were sensitive to dust mite allergen. 17/71 (24%) had detectable DMAg (mean 9.01 ng/ml [0.5–50 ng/ml]). 54/71 (76%) did not. 10/27 (38%) of mothers lacking IgE anti-der p1 antibody had detectable DMAg in their serum (mean 2.61 ng/ml [0.6–7.3 ng/ml]). 12/98 (12%) newborns had DMAg in their serum (mean 4.76 ng/ml [0.5–18 ng/ml]). All 12 had mothers with DMAg in their serum. Proportion of newborns with DMAg in their serum with mothers who were IgE anti-der p1-positive (9/12 cord blood samples) was not significantly different than the proportion of newborns lacking DMAg in their serum (62/86 cord blood samples). Conclusions There is transplacental transmission of dust mite antigen to the newborn. The level of transmission depends on maternal serum dust mite levels. Maternal dust mite atopy is not a risk factor for dust mite transmission.