Background Atopic Dermatitis (background + atopic_dermatitis)

Distribution by Scientific Domains

Selected Abstracts

The role of selected neuropeptides in pathogenesis of atopic dermatitis

J Salomon
Abstract Background Atopic dermatitis (AD) is an inflammatory skin disease of a chronic course. The role of neuropeptides in pathogenesis of this disorder is probably not crucial; however, there is evidence that these substances influence the development and course of AD. Objective The aim of this study was to evaluate the plasma level of substance P, neuropeptide Y (NPY) and calcitonin gene related peptide (CGRP) in AD patients during exacerbation and remission of the disease. Material and methods Forty-nine patients with AD, aged 17 to 56 years, participated in the study. Among this group, there were 25 males (51%) and 24 females (49%). The disease lasted from 1 to 55 years. The severity of the disease was assessed with SCORAD index. The severity of pruritus was evaluated with Visual Analog Scale and a specially designed questionnaire. Neuropeptides plasma level was detected with radioimmunoassay. Results Substance P plasma level in AD patients during exacerbation and remission was significantly higher than in the control group. There was a negative correlation between substance P plasma level and total IgE level. CGRP plasma level during exacerbation of AD was significantly lower than in healthy controls and increased in the remission. Significantly higher CGRP concentration was observed in patients suffering from severe pruritus; however, both in patients with more and less severe pruritus, CGRP plasma level was lower than in controls. Higher CGRP plasma level was also observed in patients with more severe disease. NPY plasma level in patients with AD was significantly increased both during exacerbation and remission. During remission of AD, NPY concentration was higher than during exacerbation. [source]

Percutaneous application of peptidoglycan from Staphylococcus aureus induces an increase in mast cell numbers in the dermis of mice

K. Matsui
Summary Background Atopic dermatitis (AD) is a chronic inflammatory skin disease with immunopathologic features that vary depending on the duration of the lesion. The dermis of lesional skin of AD patients shows an increased number of inflammatory cells such as mast cells, eosinophils and mononuclear cells and superficial Staphylococcus aureus colonization. Objective The purpose of this study was to determine the effects of peptidoglycan (PEG) from S. aureus on mast cell induction in murine skin. Methods PEG was applied to barrier-disrupted abdominal skin of mice every 5 days and the number of mast cells in the abdominal skin was counted 20 days after the first application. The cytokine response was investigated by RT-PCR and immunohistologic analysis. Results The number of mast cells in the skin of mice treated with PEG was increased significantly compared with that of mice given phosphate-buffered saline. In addition, application of PEG to the abdominal skin increased the expression of mRNA for transforming growth factor-,1 (TGF-,1), which supports mast cell migration, but not that for IL-3 or stem cell factor, which support both mast cell proliferation and mast cell migration. Immunohistologic analysis demonstrated that levels of TGF-,1 transcripts corresponded with those of protein synthesis in the epidermis. TGF-,1 was found to be highly expressed in keratinocytes of the basal epidermis of PEG-treated skin. Furthermore, intraperitoneal injection of anti-TGF-,1 antibodies neutralized the induction of mast cells into the skin. Conclusion These results suggest that PEG may have the ability to induce an increase in mast cell numbers in the skin through TGF-,1 production by epidermal keratinocytes. Skin inflammation might therefore be linked to colonization with S. aureus in AD patients. [source]

Different cytokine production and activation marker profiles in circulating cutaneous-lymphocyte-associated antigen+ T cells from patients with acute or chronic atopic dermatitis

C. Antúnez
Summary Background Atopic dermatitis (AD) is an inflammatory skin disease whose lesions can have two stages: acute and chronic. In skin biopsies a biphasic pattern of cytokine expression has been shown, Th2 in acute lesions and Th1 in chronic AD lesions. Objective We investigated the expression of an activation marker and a homing receptor, as well as cytokine production, in different peripheral blood T cell subpopulations from AD patients with chronic (Group A) and acute lesions (Group B) and controls. Methods We evaluated 26 adult AD patients (12 Group A, 14 Group B) and 14 non-atopic controls. IgE was measured by immunoassay. CD4, CD8, cutaneous-lymphocyte-associated antigen (CLA) and human leucocyte antigen (HLA)-DR expression, and cytokine production (IL-2, IL-13, IFN-,, TNF-,, IL-10, IL-4) were analysed in mononuclear cells by flow cytometry. Results In Group B there was a significant increase in eosinophil levels and a non-significant increase in IgE. In Group A we found an increase in CLA+CD4+ cells (8.19±1.84) compared with controls (4.83±0.53) (P<0.05) and CD4+HLA-DR+ cells in the CLA+ subpopulation (45.54±15.40) compared with controls (30.49±6.07) (P<0.05). In the CLA+CD4+ subpopulation, there was a significant increase in IL-4, IL-13 and TNF-, production in Group B (12.46±7.7, 11.26±5.97, 43.92±15.55) compared with controls (5.34±3.50, 4.54±1.78, 19.29±9.97) with no differences in Group A. Conclusion Greater immunological differences were detected in peripheral blood from patients with acute compared with chronic lesions, especially in the circulating T cell-subset with skin tropism that preferentially responded to cutaneous allergens. This is the first demonstration of phenotypic changes in circulating CLA+ T cells between AD patients with acute and chronic lesions. [source]

Distribution of HLA-A, B alleles and polymorphisms of TAP and LMP genes in Korean patients with atopic dermatitis

H. J. Lee
Background Atopic dermatitis has been seen to result from multifactorial inheritance, with interaction between genetic and environmental factors. The genetic association may differ according to the ethnic backgrounds. Objective The purpose of this study was to investigate the genetic factors in Korean atopic dermatitis patients by studying the human leucocyte antigen (HLA) class I association and polymorphisms of transporters associated with antigen presentation (TAP) and low-molecular-weight polypeptide (LMP) genes. Methods HLA-A and B genotyping was performed in 53 atopic dermatitis patients and 184 healthy controls using the standard microlymphocytotoxicity technique. TAP1, TAP2, LMP2, and LMP7 gene polymorphisms were anaylzed using the polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP), PCR-amplification refractory mutation system (ARMS), and PCR-restriction fragment length polymorphism (RFLP). Results Allele frequency of HLA-A24 was significantly increased in patients with atopic dermatitis compared to controls (P < 0.05). HLA-B alleles showed no differences in distribution between patients and controls. Genotype, phenotype, and allele frequencies of TAP1 gene also revealed no differences in distribution between patients and controls. Analysis of TAP2 gene polymorphisms showed increased frequencies of the TAP2*C allele and TAP2*A/TAP2*C genotype in atopic dermatitis patients compared to controls (P < 0.05). Distribution of LMP2 and LMP7 gene polymorphisms was similar for patients and controls. Conclusion This study demonstrates an association of atopic dermatitis with HLA-A24 and TAP2*C alleles in Korean patients. Discrepancy with the previous reports might be related to different patient characteristics and ethnic variations. [source]