Increased levels of IL-13 mRNA, but not IL-4 mRNA, are found in vivo in peripheral blood mononuclear cells (PBMC) of patients with atopic dermatitis (AD)

Abstract

SUMMARYPrevious studies using in vitro systems with various stimuli have shown that PBMC from patients with AD show increased levels of IL-4 but decreased levels of interferon-gamma (IFN-g) compared with PBMC from normal controls. However, in vitro conditions do not always mimic the in vivo condition. We therefore believe that it is important to quantify the expression of these cytokines in freshly isolated PBMC. This study examines the expression of IFN-g, IL-4 and IL-13 mRNA in freshly isolated PBMC from adult patients with AD, from patients with psoriasis vulgaris and from healthy adults, using the semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) method. Levels of IFN-g mRNA were significantly lower in PBMC of patients with AD than in controls. IL-4 mRNA levels did not differ significantly between groups. Conversely, levels of mRNA for IL-13 were significantly greater in PBMC of patients with AD than in controls. An increase in IL-13 expression may regulate the in vivo synthesis of IgE in patients with AD.

T Cell Phenotype in Allergic Asthma and Atopic Dermatitis

“…This selection was chosen in order to focus on typical allergic diseases, which are associated with high IgE production, which in turn is associated with high IL-4 expression by T cells. For AD, IL-13 expression was used as the entry criterion, as it is meant to play an important role in AD [30, 31]. Of note, IFN-γ was also detectable, but not different compared to healthy donors.…”

Staphylococcal Enterotoxin-B-Mediated Stimulation of Interleukin-13 Production as a Potential Aetiologic Factor in Eczema in Infants

“…This suggests an intrinsic predisposition of neonatal CD8+ T cells to secrete high levels of IL-13, consistent with the observed Th2 bias of the neonatal immune system. In studies using RT-PCR, IL-13 has been shown to be increased in PBMC of adult AEDS patients compared with healthy controls [20], and in investigations utilizing intracellular cytokine staining and flow cytometry, an increase in the frequency of both CD4+ and CD8+ T cells expressing increased levels of IL-13 in adult patients was demonstrated [21]. Moreover, a recent study in adults has demonstrated increased IL-13 in PBMC from adult AEDS patients in response to anti-CD3/CD28 stimulation [22].…”

Pulmonary expression of interleukin-13 causes inflammation, mucus hypersecretion, subepithelial fibrosis, physiologic abnormalities, and eotaxin production

“…In addition, IL-13 and IL-4 can be produced by different cells (39) and are differentially regulated by mediators such as IFN-α (40). The exaggerated production of IL-13 is well documented in atopic and nonatopic asthma (41)(42)(43), atopic dermatitis (44,45), allergic rhinitis (46), and chronic sinusitis (47). IL-13 also plays an important role in the pathogenesis of type II granulomatous responses (48).…”