Serum levels of vasoactive intestinal peptide are elevated in patients with atopic dermatitis.

Vasoactive intestinal peptide (VIP) has been suggested to play some roles in atopic dermatitis. Tissue of VIP levels has been reported to increase in chronic lichenified lesions of atopic dermatitis (AD). To analyze whether serum levels of VIP in AD patients are elevated compared with normal controls and correlated with the disease severity, we measured serum levels of VIP using enzyme-linked immunosorbent assay in 53 patients with AD and 21 healthy individuals. The results showed that serum levels of VIP in AD patients (345.8+/-71.5 microg/ml) were significantly higher than those in healthy individuals (307.1+/-42.6 microg/ml). However, a correlation was not found between serum VIP levels and disease severity, other markers including serum LDH levels, total serum IgE levels, and peripheral blood eosinophil counts in patients with AD. This indicates that VIP levels in AD patients were elevated not only in the skin but also in the serum, suggesting that increased serum VIP levels in the patients with AD might be involved in its pathogenesis.