Low numbers of interleukin-12-producing cord blood mononuclear cells and immunoglobulin E sensitization in early childhood


C. Nilsson, Deptartment of Pediatrics, Sachs' Children's Hospital, Södersjukhuset, S-118 83 Stockholm, Sweden. E-mail: caroline.nilsson@sos.sll.se


Background Successful pregnancies are associated with skewing towards a Th2 cytokine profile. Cytokine responses to allergens can be detected in cord blood mononuclear cells (CBMC), suggesting allergen priming already in utero.

Objective To investigate the cytokine profile in CBMC after in vitro stimulation with allergens and to relate the responses to the outcome in terms of allergic disease at 2 years of age.

Methods CBMC were isolated from 82 children. The responses to ovalbumin (OVA), birch, cat and phytohaemagglutinin (PHA) were investigated by the ELISpot technique. The numbers of IFN-γ-, IL-4- and IL-12-producing CBMC were counted for each stimulation. The children were followed prospectively; skin prick test (SPT) and RAST towards food and inhalant allergens were assessed at 24 months of age.

Results Sixteen (19.5%) children were classified as IgE sensitized (positive SPT; geqslant R: gt-or-equal, slanted3 mm and/or RAST; geqslant R: gt-or-equal, slanted0.35 kUA/L). The numbers of IL-12-producing CBMC after stimulation with birch, OVA and cat were lower among IgE-sensitized children, statistically significant for cat. IFN-γ-producing cells, did not differ in numbers between the sensitized and non-sensitized children. Children who had atopic eczema/dermatitis syndrome (AEDS) during the observation (n=53) had significantly lower numbers of IFN-γ-producing CBMC after stimulation with OVA and cat than their non-AEDS counterparts.

Conclusions Although the numbers of infants in our study are limited our data suggest that a low number of IL-12-producing CBMC is associated with IgE sensitization during early childhood and that a reduced number of IFN-γ-producing CBMC promotes the development of AEDS during the first 2 years of life.