B-cell isotype control in atopy and asthma assessed with cDNA array technology

B-cell isotype switching and the production of IgE is regulated by a variet y of gene products through different mechanisms. A better understanding of these processes has the potential to identify markers of disease and new th erapeutic targets. The aim of the study was to investigate human B-cell iso type control and IgE production in atopy and asthma with cDNA array technol ogy. Eighteen atopic asthmatic, eight atopic nonasthmatic, and fourteen hea lthy control subjects were included. Peripheral blood mononuclear cells wer e separated by gradient centrifugation, mRNA was purified, and the reverse- transcribed probes were hybridized to cDNA membranes. Group differences wer e assessed with the Mann-Whitney U-test. Twenty-three of seventy-eight test ed IgE-related genes had significantly altered expression in atopy and asth ma compared with that in the healthy subjects. The differentially expressed genes include surface molecules involved in T- and B-cell interaction and activation, cytokines, intracellular signaling products, and transcription factors. In conclusion, both atopic nonasthmatic and atopic asthmatic indiv iduals had activated proinflammatory pathways, a minimal requirement for B- cell isotype switching, and a clear net pro-IgE cytokine climate.