Risk factors for infantile atopic dermatitis and recurrent wheezing.

BACKGROUND: The pathogenic mechanisms of atopic dermatitis (AD) and recurrent wheezing (RW) during infancy are not fully understood. OBJECTIVE: We evaluated immunological markers associated with AD and RW during infancy. METHODS: We followed a cohort (n = 314) from birth to 14 months of age. Some of the participants underwent a physical examination and blood test at 6 and 14 months of age. Univariate and multivariate logistic regression analysis and receiver operating characteristic curve analysis were performed to find which immunological markers could be risk factors for AD and RW. RESULTS: Of 16 immunological markers found in cord blood, only immunoglobulin (Ig) E was associated with AD at 6 months of age (adjusted OR [aOR], 1.607). None of the markers was associated with AD or RW at 14 months of age. Of 23 immunological markers at 6 months of age, total IgE (aOR, 1.018) and sensitization to egg white (aOR, 23.246) were associated with AD at 14 months of age. Phytohemagglutinin (PHA)-induced production of interleukin (IL) 4 from peripheral blood mononuclear cells (PBMCs) (aOR, 1.043) was associated with RW at 14 months of age. CONCLUSION: Cord blood IgE was a risk factor for AD at 6 months of age. Total IgE and sensitization to egg white at 6 months of age were risk factors for AD at 14 months of age. PHA-induced IL-4 production in PBMCs at 6 months of age was a risk factor for RW at 14 months of age.

Characterization of T-cell clones specific to ovomucoid from patients with egg-white allergy.

BACKGROUND: Allergic reactions to foods are specific problems for infants and young children. Ovomucoid (OM) is one of the major allergens found in egg-white. We previously established several T-cell clones (TCCs) specific to OM in non-polarizing conditions from 4 patients (TM and YN are immediate-type, IH and YT are non-immediate-type) with egg-white allergy. We characterized their reactive epitopes, antigen-presenting molecules (HLA class II), and usage of TCR alpha and beta genes and the CDR3 loop sequence. OBJECTIVE: The objective of this study was to characterize these seven clones (TM 1.3, TM1.4,YN 1.1, YN1.5, IH3.1, IH3.3 and YT6.1) for cytokine production patterns and cell-surface-marker phenotypes. METHODS: We measured the production of cytokines, namely interleukin (IL)-4, IL-5 and interferon-gamma (IFN-gamma) by stimulation with ovomucoid peptides and stained intracellular IL-4 and IFN-gamma, and determined cell-surface markers using anti-interleukin-12 receptor (IL-12R) beta1, anti-IL-12Rbeta2 and anti-interleukin-18 receptor alpha (IL-18Ralpha). RESULTS: Most TCCs secreted both IL-4 and IFN-gamma in response to the OM peptide mixture, but the secretion patterns were variable; an IFN-gamma dominant pattern was seen in IH3.1 andYT6.1, an IFN-gamma>IL-4 pattern in TM1.3 and TM1.4, an IL-4> IFN-gamma pattern in YN1.5. In intracellular IFN-gamma and IL-4 staining, IFN-gamma single-positive cells were predominant in TM1.3, TM1.4, IH3.1 and YT6.1 and IFN-gamma and IL-4 double-positive cells were predominant in YN1.1, YN1.5 and IH3.3. All TCCs were IL-12Rbeta1-positive, and TM1.3, IH3.1, IH3.3 and YT6.1 were both IL-12Rbeta2- and IL-18Ralpha-positive. TM1.4 and YN1.1 were both IL-12Rbeta2- and IL-18Ralpha-negative. Based on these results, TM1.3 and TM1.4, IH3.1 and YT6.1 had a predominantly Th1 character and YN1.1, YN1.5, and IH3.3 possessed a predominantly Th0 character. CONCLUSIONS: The phenotypes of TCCs were not in accordance with their clinical manifestations. TCCs established from patients with immediate-type hypersensitivity had either the Th1 or Th0 phenotype as well as those with non-immediate-type hypersensitivity.