ITCH AND INFLAMMATION-INDUCED BY INTRADERMALLY INJECTED INTERLEUKIN-2 IN ATOPIC-DERMATITIS PATIENTS AND HEALTHY-SUBJECTS

To explore the pruritogenic and inflammatory effects of cytokines, a single dose of 20 mu g recombinant human interleukin-2 was injected intradermally into eight patients with atopic dermatitis and eight healthy controls, The study was double-blind and randomized with glucose as a negative control, The effects were evaluated by recording local itch and erythema over 72 h and by examining skin biopsies taken at 24 h and 72 h. In patients and controls, interleukin-2 provoked a low-intensity local itch with maximal intensity between 6 h and 48 h and erythema with maximal extension between 12 h and 72 h. In the atopic dermatitis patients, these reactions tended to appear earlier and were less pronounced than in the healthy controls, Interleukin-2 induced dermal mononuclear cell infiltrates consisting mainly of CD3(+) cells. A majority of the T cells were CD4(+). The number of dermal CD25(+), HLA-DR(+) and ICAM-1(+) cells was also increased at the interleukin-2 injection sites, In the epidermis, interleukin-2 induced spongiosis and exocytosis as well as HLA-DR(+) and ICAM-1(+) keratinocytes, The microscopic findings tended to be more prominent at 72 h than at 24 h in both groups, but with a somewhat slower onset in the atopic dermatitis patients, In conclusion, a single intradermal injection of interleukin-2 induced local itch, erythema, dermal T-cell infiltrates, spongiosis, exocytosis and activation of keratinocytes both in atopic dermatits patients and in healthy controls.