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

Abstract

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