IL-13 over-expression in skin is not confined to IgE-mediated skin inflammation.
IL-13 is produced by T cells and, like IL-4, it can induce the production of IgE and IgG4. In order to investigate if IL-13 is a specific marker for atopic dermatitis (AD), IL-13 gene expression was analysed in chronic lichenified lesions and non-lesional skin of patients with AD, in involved and non-involved skin of patients with psoriasis, in positive tuberculin reactions in non-atopics, and in the skin of healthy control subjects. Patients with AD (n = 9) showed sensitization to common air-borne allergens (positive Phadiatop) and had total serum IgE values in the range from 10 to 4800 kU/l (median 170 kU/l). Competitive reverse transcription-polymerase chain reaction (RT-PCR) was used to assess IL-13 gene expression in skin biopsy specimens. IL-13 gene expression was markedly higher in chronic lichenified lesions of patients with AD (P < 0.01), and in the positive tuberculin reactions (P < 0.01; n = 12) than in skin from healthy control subjects (n = 10). However, there was no significant difference in IL-13 gene expression in the skin of patients with psoriasis (n = 10) and that of healthy control subjects. The dermal cell infiltrates were larger and the relative amount of CD3+ and CD4+ cells in these infiltrates was higher in the skin of subjects with a positive tuberculin reaction than in lichenified AD skin. However, these differences were not reflected in differences in IL-13 gene expression. Different triggers of IL-13 gene expression may influence the diverse patterns of inflammation seen in different inflammatory skin disorders.
Van der Ploeg
I
I
Department of Laboratory Medicine, Karolinska Hospital and Institute, Stockholm, Sweden.
Jeddi Tehrani
M
M
Matuseviciene
G
G
Wahlgren
C F
CF
Fransson
J
J
Scheynius
A
A
D000293:Adolescent; D000328:Adult; D000368:Aged; D000485:Allergens / Q000276:immunology; D001706:Biopsy; D017252:CD3 Complex / Q000032:analysis / Q000378:metabolism; D015704:CD4 Antigens / Q000032:analysis / Q000378:metabolism; D016827:CD8 Antigens / Q000032:analysis / Q000378:metabolism; D003876:Dermatitis, Atopic / Q000097:blood / Q000276:immunology*; D005260:Female; D015870:Gene Expression; D006801:Humans; D007073:Immunoglobulin E / Q000032:analysis / Q000276:immunology*; D007150:Immunohistochemistry; D018793:Interleukin-13 / Q000235:genetics* / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011565:Psoriasis / Q000097:blood / Q000276:immunology; D012313:RNA / Q000235:genetics / Q000378:metabolism; D012867:Skin / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D014373:Tuberculin / Q000097:blood / Q000276:immunology
D000485:Allergens; D017252:CD3 Complex; D015704:CD4 Antigens; D016827:CD8 Antigens; D018793:Interleukin-13; D014373:Tuberculin; D007073:Immunoglobulin E; D012313:RNA