Staphylococcus aureusskin colonization in atopic dermatitis children is associated with decreased IFN‐γproduction by peripheral blood CD4⁺and CD8⁺T cells

Abstract

Atopic dermatitis (AD) is a chronic inflammatory skin disorder, which is associated with an increased expression of Th2 cytokines with concomitant decrease in IFN-gamma production by circulating CD4+ and CD8+ T cells. The skin of patients with AD is often colonized by Staphylococcus aureus, which may reflect in changes in immunological parameters. The aim of the study was flow cytometric measurement of some peripheral blood lymphocyte subsets expressing naive/memory marker (RA/RO) and activation marker (CD25) as well as intracellular production of IFN-gamma by peripheral blood CD4+ and CD8+ T cells from varied severity AD children and determine the impact of S. aureus skin colonization on cytokines profiles. There was a significant increase in the percentage of CD4+ and CD8+ T cells producing IL-4 and IL-13 and decrease in the percentage of CD4+ and CD8+ T cells producing IFN-gamma upon in vitro stimulation with phorbol 12-myristate 13-acetate and ionomycin in children with AD compared to healthy ones. The absolute number of CD4+ and CD8+ T cells expressing memory marker CD45RO was elevated as compared with controls. The severity of AD was positively correlated with the percentage of lymphocyte subsets: CD45RO+, CD4+CD45RO+, and the percentage of CD3+ and CD4+ expressing CD25 as well as the number of S. aureus on the skin. In conclusion, both CD4+ and CD8+ memory T cells are involved in the immunopathogenesis of AD. S. aureus skin colonization is related with disease severity and changes in expression of CD45RO and CD25 on T cells. A decrease in the percentage of CD4+ and CD8+ T cells producing IFN-gamma in AD children may explain propensity for skin infection.

Clinical Features and Immunological Markers of Atopic Dermatitis in Elderly Patients

“…Our findings confirmed that 21% of elderly patients had AD with low total IgE and were not allergic to common allergens. These values are slightly higher than those of other reports (5–15%), which have investigated younger populations [9,14,15]. It is possible that AD with low total IgE is more prevalent in elderly AD patients.…”

“…Blood lymphocyte profiles were measured via the whole-blood method using fresh 10-ml EDTA blood samples according to Machura et al [9]. The following lymphocyte markers were measured using ImmunoGEN kits (BD Bioscience) and a FACSCanto II flow cytometer (Becton Dickinson): CD3, CD29, CD1656, CD4, CD8 and HLADR.…”

Decrease in circulating Th17 cells correlates with increased levels of CCL17, IgE and eosinophils in atopic dermatitis

“…Teramoto et al showed a reduced ability of IFN-g production by PBMCs was associated with an elevated serum IgE levels in AD [33]. Mauchra et al found that decreased INF-g production by peripheral blood in AD children was negatively correlated with the number of skin colonization of Staphylococcus aureus and SCORAD index [34]. Meanwhile, Kä llströ m et al showed the decrease in IFN-g + cells did not necessarily correlate with the serum levels of IgE [35].…”

Allergic skin diseases

“…77 Furthermore, an inverse relationship between skin colonization with S aureus and spontaneous T cell-derived IFN-g production has been observed. 78 Biphasic T H 2-T H 1 cytokine skin response. Acute AD skin lesions are associated with the infiltration of T H 2 cells expressing increased levels of IL-4, IL-13, and IL-31, a pruritogenic T H 2 cytokine that correlates with severity of AD.…”