The association between serum interleukin 16 (IL-16) levels and degree of sensitization was assessed in 85 atopic dermatitis (AD) patients. Thirty-six healthy age-matched volunteers and 20 psoriasis patients served as controls. Sera from AD patients had significantly more levels of IL-16 than volunteers or psoriasis patients. A significant correlation was found between IL-16 and immunoglobulin E (IgE) levels (R = 0.48; P = 0.004). IL-16 levels were significantly increased in the AD subgroups in which specific IgE was detected against 1-5 or >5 antigens. IL-16 correlates with the degree of sensitization, but the link is not as strong as is the case with serum IgE. IL-16 has a complex role in ...