Interleukin-4 as a New Index of Disease Severity in Atopic Dermatitis

Lee, Seong Hun; Lee, Joo Heung; Lee, Seung Chul; Kim, Young Keun

Abstract

BACKGROUND: Interleukin-4(IL-4) from the Th2 subset of lymphocytes has been known to have a key role in the pathogenesis of atopic dermatitis. Blood levels of IgE, often reflecting the severity of allergic diseases, are not always elevated in patients with atopic dermatitis due to its homocytotrophic characteristics.
OBJECTIVE
We propose that IL-4 can substitute or at least complement the role of IgE as an index of disease severity of atopic dermatitis.
METHODS
Eleven patients with atopic dermatitis and five normal controls were included in this study. Before treatment, we evaluated the clinical severity of atopic dermatitis by the method described elsewhere with some modification which employed extent, duration, and intensity of skin lesions. Based on this criteria, we divided patients into 'severe and mild groups. With blood samples drawn from patients and normal controls, we measured IL-4 and IgE values. After a treatment period of I to 2 months, when all of the patients became free of symptoms and signs of atopic dermatitis, patients in each group were re-evaluated for ehanges of IL-4 and IgE values. IL-4 values were determined with a Predicata human interleukin-4 kit from Genzyme diagnostics (Predicta IL-4 kit) and ELISA reader (CRES UV900, Biotek). IgE values were measured .with IMx total IgE assay system from Abott laboratories (model 8389-0).
RESULTS
l. Of eleven patients, six were mild and five were severe in clinical severity. 2. IL-4 levels were decreased from the pre-treatment average value of 57.149+/- 40.079 pg/ml to a post-treatment average value of 32.072+/- 16.912 pg/ml (p<0.05) which was similar to average normal control value, 36.690+/- 24.451 pg/ml. 3. IgE levels were similarly decreased from an average value of 230.2 86.4 IU/ml before treatment to one of 171.S+/-79.4 IU/ml after treatment (p<0.05). 4. This tendency of post-treatment lowering of values became more apparent in severe groups (p<0.05) but less obvious in mild groups both in terms of IL-4 and IgE (p>0.1).
CONCLUSION
We conclude that IL-4 is not only involved in the pathogenesis but can also be used as a main index of disease severity in atopic dermatitis especially when the clinical severity is more than mild.