Expansion of FOXP3-positive CD4+CD25+ T cells associated with disease activity in atopic dermatitis.
BACKGROUND
FOXP3-positive CD4+CD25+ T cells are known to have an immunoregulatory function by means of preventing T-cell reactivity to both self- and non-self-antigens. However, the role of these cells in the pathogenesis of allergic diseases is not clear.


OBJECTIVE
To evaluate the quantity and quality of circulating FOXP3-positive T cells in patients with atopic dermatitis (AD).


METHODS
Peripheral blood mononuclear cells were isolated from 35 AD patients (mean [SD] age, 27.1 [7.5] years) and 36 controls (mean [SD] age, 27.5 [10.0] years). Cellular FOXP3 expression was analyzed using flow cytometry. Characteristics of FOXP3-positive T cells were evaluated with respect to cytokine production capability and suppressive function.


RESULTS
Frequencies of circulating FOXP3+CD25+ cells in the CD4+ T-cell population of AD patients were significantly higher than those in controls (mean [SD], 7.4% [4.6%] vs 4.5% [1.3%]; P = .002) and correlated with their Scoring Atopic Dermatitis (SCORAD) scores (r = 0.74, P = .008) and peripheral blood eosinophil counts (r = 0.72, P < .001). In the patients whose samples were analyzed at intervals of 1 to 2 months, frequencies of FOXP3-positive T cells were decreased as their skin lesions improved, regardless of medicines used. FOXP3-positive CD4+ T cells from patients, as well as those from controls, showed little capability to synthesize interferon gamma and interleukin 4. No differences were found in suppression abilities of CD4+CD25+ T cells between AD patients and controls.


CONCLUSIONS
Our data suggest that dynamic fluctuation in numbers of circulating FOXP3-positive regulatory T cells might contribute to the pathogenesis of AD.
Ito
Yasunori
Y
Department of Pediatrics, Graduate School of Medicine, University of Toyama, Toyama, Japan.
Adachi
Yuichi
Y
Makino
Teruhiko
T
Higashiyama
Hiroyuki
H
Fuchizawa
Tatsuya
T
Shimizu
Tadamichi
T
Miyawaki
Toshio
T
D000293:Adolescent; D000328:Adult; D018791:CD4 Lymphocyte Count; D018920:Coculture Techniques; D003876:Dermatitis, Atopic / Q000175:diagnosis / Q000188:drug therapy / Q000209:etiology / Q000276:immunology*; D004804:Eosinophils / Q000166:cytology; D005260:Female; D051858:Forkhead Transcription Factors / Q000378:metabolism*; D006801:Humans; D007108:Immune Tolerance / Q000276:immunology; D007073:Immunoglobulin E / Q000097:blood; D007371:Interferon-gamma / Q000378:metabolism; D053645:Interleukin-2 Receptor alpha Subunit / Q000378:metabolism*; D015847:Interleukin-4 / Q000378:metabolism; D007958:Leukocyte Count; D008297:Male; D016176:T-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D050378:T-Lymphocytes, Regulatory / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D055815:Young Adult
C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; C508017:IL2RA protein, human; C508598:IL4 protein, human; D053645:Interleukin-2 Receptor alpha Subunit; D015847:Interleukin-4; D007073:Immunoglobulin E; D007371:Interferon-gamma