[Study on genetic phenotype of asthma through examination of neonates' cord blood cells and interleukin-4].

Objective: To identify the genetic phenotypes of asthma based on the examination of the umbilical cord blood from neonates of the mothers with asthma.

Methods: Umbilical cord blood was collected from 39 asthmatic lying-in women and 46 healthy lying-in women. Eosinophils and basophils absolute counts, total immunoglobulin E, and interleukin (IL)-4 were examined. Mononuclear cells (MNCs) from the umbilical cord blood were cultured. IL-4 in the supernatant was test by ELISA. White cells were collected from the umbilical cord blood. Basophils and T lymphocytes were purified, cultured, and stimulated by hyper osmotic mannitol. RT-PCR was used to test the mRNA expression of IL-4 in the supernatant.

Results: There were no significant differences in the counts of basophils and eosinophils, total IgE, and IL-4 in the cord blood, and IL-4 in the supernatant of cultured MNCs. After stimulation of hyper-osmotic mannitol, equine anti-human IgE, and dust mite the HBDT positive rates were 64.10%, 17.95%, and 0% respectively in the neonates of asthmatic women group, the former two rates being both significantly higher than those in the neonates of healthy women group (15.22% and 2.17% respectively, P < 0.05 and P < 0.025). After stimulation of hyper-osmotic mannitol, IL-4 mRNA was markedly expressed in the purified basophils of both groups and was almost not expressed in the purified eosinophils of both groups.

Conclusion: There is qualitative abnormalities in the basophils from the cord blood of neonates of asthmatic mothers that strongly express IL-4 mRNA. Such characteristics may be an asthma-related genetic phenotype.