Whereas IL-1β promotes Th1 and Th17 responses and gastric immunopathology, IL-18 is required for Treg differentiation, H. pylori persistence, and protection against allergic asthma, which is a hallmark of H. pylori-infected mice and humans.
Our meta-analysis suggests that IL-18-607C/A and -137G/C polymorphisms may be protective factors for the risk of allergic asthma and allergic dermatitis, respectively.
To examine the relationship of a genetic, haplotype-tagging promotor variant -137G/C in the IL-18 gene with atopic asthma in a large, well-characterized and population-based study of adults.
Furthermore, intrinsic defects of the CD4(+) T cells, which reduce their IL-12 receptor beta 2 expression in response to IL-12 and/or IL-18 stimulation, are evident and are importantly involved in the Th1/Th2 imbalance of patients with atopic asthma.