Ra. Taha et al., IN-VIVO EXPRESSION OF CYTOKINE RECEPTOR MESSENGER-RNA IN ATOPIC-DERMATITIS, Journal of allergy and clinical immunology, 102(2), 1998, pp. 245-250
Background: Atopic dermatitis (AD) is a chronic inflammatory skin dise
ase with immunopathologic features that vary depending on the duration
of the lesion. Acute lesions are associated with a T-cell infiltrate
and a high expression of IL-4 mRNA compared with chronic lesions, unin
volved AD skin, or skin from normal control subjects. Chronic lesions
are rich in eosinophils and monocyte/macrophages and contain a greater
number of IL-5, granulocyte-macrophage colony-stimulating factor (GM-
CSF), and IL-12 (p40) mRNA-positive cells. Objectives: In this study,
we investigated the mRNA expression of the IL-4 receptor (IL-4R alpha)
, IL-5R alpha, GM-CSFR alpha, and IL-12R beta(2) in biopsy specimens f
rom acute and chronic AD lesions, uninvolved AD skin, normal skin, and
psoriatic skin lesions. Methods: Cytokine receptor mRNA was examined
in paraformaldehyde-fixed biopsy specimens with in situ hybridization
with specific antisense riboprobes. Results: Acute and chronic skin le
sions exhibited a significant increase in numbers of IL-5R alpha and G
M-CSFR alpha mRNA-positive cells compared with uninvolved AD skin and
normal skin (P <.001). Chronic skin lesions had a significantly greate
r number of IL-5R alpha and GM-CSFR alpha mRNA-positive cells when com
pared with acute AD skin (P <.001), In contrast, IL-4R alpha mRNA expr
ession was increased in acute but not chronic AD lesions compared with
uninvolved and normal skin (P <.001). No significant differences were
observed in numbers of IL-12R beta(2) mRNA-positive cells when compar
ing acute AD, chronic AD, uninvolved AD, and normal skin. In psoriatic
skin, the numbers of GM-CSFR alpha and IL-12R beta(2) mRNA-positive c
ells were significantly increased compared with acute AD lesions, unin
volved skin, and normal control skin (P <.01). Conclusions: These resu
lts demonstrate that acute AD is associated with a high expression of
IL-4R alpha, whereas IL-5R alpha and GM-CSFR alpha mRNA are predominan
tly increased in chronic AD and to lesser extent in acute lesions. The
se findings support the biphasic role of IL-4, IL-5, and GM-CSF in the
pathophysiology of AD.