Differences in cytokine production by peripheral blood mononuclear cells (PBMC) between patients with atopic dermatitis and bronchial asthma.

It is widely accepted that type 2 helper T (Th2) lymphocytes play a crucial role in the pathogenesis of atopic dermatitis (AD) as well as bronchial asthma (BA). We measured the amounts of IL-5 and interferon-gamma (IFN-gamma) produced by PBMC upon stimulation with house dust mite (HDM) or Candida albicans (CA) in 17 children (3-15 years) with AD, and compared these values with those of 16 children with BA. Although IL-5 production by PBMC upon stimulation with HDM in patients with AD was significantly higher than that in 13 non-atopic controls (geometric mean = 23.4 pg/ml versus 5.9 pg/ml, P < 0.05), it was significantly lower than that in patients with BA (177.8 pg/ml, P < 0.001). The amount of IL-5 produced by PBMC upon stimulation with CA was also significantly lower in patients with AD than in those with BA (7.2 pg/ml versus 100.0 pg/ml, P < 0.001). The production of IFN-gamma by PBMC stimulated with HDM or CA was also significantly lower in patients with AD than in those with BA (HDM 4. 3 pg/ml versus 12.6 pg/ml, P < 0.05; CA 6.5 pg/ml versus 60.3 pg/ml, P < 0.001). Consequently the ratio of IL-5 to IFN-gamma production was high not only in patients with BA but also in those with AD. These findings suggest that there are some differences in the regulation of in vivo cytokine production between patients with AD and those with BA, although a Th2-dominant profile is common to both.