Activation-regulated Chemokine Levels Research Articles

Chlorella vulgaris Attenuates Dermatophagoides Farinae-Induced Atopic Dermatitis-Like Symptoms in NC/Nga Mice.

Atopic dermatitis (AD) is a chronic and inflammatory skin disease that can place a significant burden on quality of life for patients. AD most frequently appears under the age of six and although its prevalence is increasing worldwide, therapeutic treatment options are limited. Chlorella vulgaris (CV) is a species of the freshwater green algae genus chlorella, and has been reported to modulate allergy-inducible factors when ingested. Here, we examined the effect of CV supplementation on AD-like symptoms in NC/Nga mice. CV was orally administrated for six weeks while AD-like symptoms were induced via topical application of Dermatophagoides farinae extract (DFE). CV treatment reduced dermatitis scores, epidermal thickness, and skin hydration. Histological analysis also revealed that CV treatment reduced DFE-induced eosinophil and mast cell infiltration into the skin, while analysis of serum chemokine levels indicated that CV treatment downregulated thymus- and activation-regulated chemokine (TARC) and macrophage-derived chemokine (MDC) levels. In addition, CV treatment downregulated mRNA expression levels of IL-4 and IFN-γ. Taken together, these results suggest that CV extract may have potential as a nutraceutical ingredient for the prevention of AD.

Study of pruritus in chronic hepatitis C patients

To investigate the occurrence and severity of pruritus in chronic hepatitis C patients treated with or without interferon (IFN) therapy. A total of 89 patients with chronic hepatitis C and 55 control (non-hepatitis) patients were asked to rate their experience of diurnal and nocturnal pruritus in the preceding week using a visual analogue scale (VAS) and a five-point scale, respectively. Blood samples were taken and serum thymus and activation-regulated chemokine (TARC) levels were measured by enzyme-linked immunosorbent assay. A significantly greater proportion of chronic hepatitis C patients experienced nocturnal pruritus compared with control (58.4% vs 5.5%, P < 0.0001). Chronic hepatitis C patients also had more severe pruritus compared with control patients, indicated by the higher mean VAS scores in both the IFN-treated and non-IFN-treated groups. In particular, patients who received combined peginterferon alfa-2b and ribavirin had significantly higher mean VAS scores than those receiving peginterferon alfa-2a or no IFN treatment. Serum TARC levels did not correlate with pruritus scores, and no significant differences in TARC levels were observed between the IFN-treated and non-IFN-treated groups. Patients with chronic hepatitis C experience pruritus more than those without. Serum TARC levels do not correlate with pruritus severity in chronic hepatitis C patients.

Inhibitory Effects of Camellia sinensis Extract on the Development of Atopic Dermatitis-like Lesions in NC/Nga Mice

Atopic dermatitis (AD) syndrome is one of the most common and severe skin diseases in Korea; a large population has this disease. We examined the effects of the extract from the leaf and sprig of Camellia sinensis on the development of AD by using NC mice as a model of atopic dermatitis. Oral administration of the extract to NC/Nga mice treated with 2,4?dinitrochlorobenzene (DNCB) inhibited the development of AD-like skin lesions as shown by a significant decrease in the skin symptoms of the disease and a decrease in ear thickness and levels of immunoglobulin E (IgE) and thymus-and activation-regulated chemokine (TARC) level in the skin. Administration of the extract markedly suppressed the DNCB-induced mRNA expression of interleukin 4 (IL-4) and tumor necrosis factor <TEX>${\alpha}$</TEX> (TNF-<TEX>${\alpha}$</TEX>). The findings suggest that transdermal application of the extract may modulate in the skin of NC/Nga mice. The extract was effective for the prevention and treatment of AD.

Utility of serum thymus and activation-regulated chemokine as a biomarker for monitoring of atopic dermatitis severity

Serum thymus and activation-regulated chemokine (sTARC) levels reflect disease severity of atopic dermatitis (AD) in small study populations. It remains unclear whether sTARC is a reliable outcome measurement for AD severity in heterogeneous AD populations in daily practice. We sought to assess the utility of sTARC as a biomarker for monitoring AD severity in adults in daily practice. sTARC, clinical skin score (Six Area, Six Sign AD [SASSAD]), and body surface area measurements were collected from all adult patients with AD visiting our clinic between March 2009 and March 2012, at first visit or exacerbation (baseline). In addition, data from short-term and long-term follow-up visits were collected. At baseline sTARC levels ranged widely (n = 320; minimum-maximum: 3-50,400 pg/mL) and sTARC and SASSAD or body surface area correlated moderately. In the majority of patients, sTARC and SASSAD or body surface area changed congruently during follow-up. Data were collected retrospectively. sTARC may represent a suitable biomarker for monitoring of AD severity in daily practice.

Serum Thymus and Activation-Regulated Chemokine Level Monitoring May Predict Disease Relapse Detected by PET Scan after Reduced-Intensity Allogeneic Stem Cell Transplantation in Patients with Hodgkin Lymphoma

Patients with relapsed and refractory Hodgkin lymphoma (HL) may experience long-term survival after allogeneic stem cell transplantation (alloSCT), but disease recurrence represents the main cause of treatment failure. Positron-emission tomography (PET)–positive patients after alloSCT have a dismal outcome. Serum thymus and activation-regulated chemokine (TARC) is produced by Reed-Sternberg cells and may be a marker of disease. Our study aimed at assessing whether TARC levels after alloSCT correlated with disease status and whether TARC monitoring could increase the ability to predict relapse. Twenty-four patients were evaluated in a prospective observational study. TARC serum level and PET were assessed before and after alloSCT during the follow-up (median, 30 months; range, 2 to 54). Before alloSCT, the median TARC level was 721 pg/mL (range, 209 to 1332) in PET-negative patients and 2542 pg/mL (range, 94 to 13,870) in PET-positive patients. After alloSCT, TARC was 620 pg/mL (range, 12 to 4333) in persistently PET-negative patients compared with 22,397 pg/mL (range, 602 to 106,578) in PET-positive patients (P < .0001). In 7 patients who relapsed after alloSCT, TARC level increased progressively even before PET became positive, with a median fold increase of 3.19 (range, 1.66 to 7.11) at relapse. The cut-off value of 1726 pg/mL had a sensitivity of 100% and a specificity of 71% for PET positivity. Patients with at least 1 TARC value above 1726 pg/mL during the first year after alloSCT had a worse progression-free survival (P = .031). In conclusion, TARC was correlated with disease status and its monitoring may be able to predict PET positivity after alloSCT, thus potentially allowing an early immune manipulation.

Clinical significance of serum vascular endothelial-cadherin levels in inflammatory skin diseases.

Clinical significance of serum vascular endothelial-cadherin levels in inflammatory skin diseases.

English

Serum thymus and activation-regulated chemokine (TARC) levels are associated with the disease activity of patients with atopic dermatitis (AD) and sensitively reflect short-term changes in skin conditions. The main treatment for AD is topical agent application. This study investigated the relationship between serum TARC levels and the dosage of topical agents, including corticosteroids and/or tacrolimus, in patients with AD. The serum TARC levels of 56 AD patients and the amounts of topical agents prescribed to them were investigated retrospectively. The weekly reduction in serum TARC levels and weekly dosage of topical agents among AD patients were compared and their associations were evaluated. The dosage of topical agents was closely related to serum TARC levels. One gram of strong rank steroid or the equivalent amount of steroid/tacrolimus is required to reduce serum TARC levels by 9.94 pg/mL weekly in moderate to severe AD patients. Higher initial TARC levels require more topical agent, which results in a more rapid decrease in TARC levels. The serum TARC levels and eosinophil numbers in peripheral blood are significantly correlated. Serum TARC level improvement and topical agent dosage are strongly correlated. TARC and eosinophil numbers are significantly correlated, but the wider range of TARC levels seems to be clinically more useful for monitoring AD severity. The serum TARC level is a very sensitive biomarker for monitoring the severity and treatment response in AD.

Possible pathogenic role of T helper type 9 cells and interleukin (IL)-9 in atopic dermatitis

T helper type 9 (Th9) cells are a novel identified subset of CD4(+) T helper cells, which could partly contribute to allergic inflammation, while the precise contribution of Th9 cells in atopic dermatitis (AD) remains unknown. We aimed to explore the possible role of Th9 cells in AD pathogenesis. The Th9 cell percentage, transcription factor PU.1 and cytokine interleukin (IL)-9 mRNA levels, as well as IL-9 serum concentration in peripheral circulation, were measured in AD patients, psoriasis patients and healthy controls. The Th9 cell percentage, PU.1 and IL-9 expression levels of AD patients were all increased significantly compared with the other two control groups (P < 0·01), and correlated positively with SCORing Atopic Dermatitis index, serum immunoglobulin (Ig)E and thymus- and activation-regulated chemokine (TARC) levels (P < 0·05). In simple AD patients and AD patients complicated by allergic rhinitis or asthma, there were no significant differences in the Th9 cell percentage, PU.1 and IL-9 expression levels between them. At the same time, IL-9 and vascular endothelial growth factor (VEGF) mRNA levels were detected in AD lesions and normal skin samples, which were both distinctly elevated in AD lesions, and there was a positive association between them (P < 0·01). Keratinocytes were cultured with IL-9 stimulation and the secretion of VEGF was detected. IL-9 can promote the secretion of VEGF by keratinocytes in a time- and dose-dependent manner. In conclusion, the expansion of the Th9 cell subset, up-regulation of the PU.1 transcription factor and increased secretion of the IL-9 cytokine may contribute to the pathogenesis of AD, which may be supported by the increased release of VEGF by keratinocyes after IL-9 stimulation.

Case of Netherton syndrome with an elevated serum thymus and activation‐regulated chemokine level

Case of <scp>N</scp>etherton syndrome with an elevated serum thymus and activation‐regulated chemokine level

Severe psoriasis vulgaris exhibiting a high serum thymus and activation-regulated chemokine level: Possible association of T-helper 2 conditions

Severe psoriasis vulgaris exhibiting a high serum thymus and activation-regulated chemokine level: Possible association of T-helper 2 conditions

Correlation between serum thymus and activation-regulated chemokine levels and stratum corneum barrier function in healthy individuals and patients with mild atopic dermatitis

Serum thymus and activation-regulated chemokine (TARC) levels closely reflect the disease activity of atopic dermatitis (AD). AD is characterized by impaired epidermal barrier function and atopic dry skin. However, dry skin is also a very common problem in healthy individuals. To investigate the relationship between serum TARC levels and epidermal barrier function in healthy subjects and patients with mild AD. This study included 2 groups, 121 healthy subjects (healthy group) and 66 patients with mild AD (mild AD group). Barrier function was assessed by transepidermal water loss (TEWL) and stratum corneum hydration (SCH). Significantly elevated serum TARC levels and TEWL values and significantly decreased SCH values were detected in the mild AD group compared to those in the healthy group. In the mild AD group, serum TARC levels were significantly correlated with TEWL values and were inversely correlated with SCH values. Importantly, serum TARC levels were also inversely correlated with SCH values in the healthy controls. TEWL values in the healthy group tended to be correlated with TARC levels but did not reach statistical significance. Together with TEWL and SCH, serum TARC level is a useful biomarker, reflecting impairment of epidermal function in AD patients as well as healthy subjects.

Plasma thymus and activation-regulated chemokine as an early response marker in classical Hodgkin's lymphoma

Plasma thymus and activation-regulated chemokine is a potential biomarker for classical Hodgkin's lymphoma. To define its value as a marker to monitor treatment response, we correlated serial plasma thymus and activation-regulated chemokine levels with clinical response in newly diagnosed and relapsed classical Hodgkin's lymphoma patients. Plasma was collected from 60 (39 early stage and 21 advanced stage) newly diagnosed classical Hodgkin's lymphoma patients before, during, and after treatment, and from 12 relapsed patients before and after treatment. Plasma thymus and activation-regulated chemokine levels were determined by enzyme-linked immunosorbent assay and were related to pre-treatment metabolic tumor volume, as measured by quantification of 2-[18F]fluoro-2-deoxyglucose positron emission tomography images, and to treatment response. Baseline plasma thymus and activation-regulated chemokine levels correlated with stage of disease and bulky disease, and more closely with metabolic tumor volume. Response to treatment was observed among 38 of 39 early stage and 19 of 21 advanced stage patients. Reduction in plasma thymus and activation-regulated chemokine to normal range levels could be observed as early as after one cycle of chemotherapy in all responsive patients, while plasma levels remained elevated during and after treatment in the 3 non-responsive patients. Plasma thymus and activation-regulated chemokine was elevated in all 12 relapsed patients at time of relapse and remained elevated after salvage treatment in the 4 non-responsive patients. Baseline plasma thymus and activation-regulated chemokine levels correlate with classical Hodgkin's lymphoma tumor burden and serial levels correlate with response to treatment in patients with classical Hodgkin's lymphoma.

Enteric-coated mycophenolate sodium versus cyclosporin A as long-term treatment in adult patients with severe atopic dermatitis: A randomized controlled trial

Cyclosporin A (CsA) is frequently used in the treatment of severe atopic dermatitis (AD). Enteric-coated mycophenolate sodium (EC-MPS) may be an alternative with equal efficacy and fewer side effects. The aim of this observer-blinded randomized controlled trial was to compare EC-MPS with CsA as long-term treatment in adult patients with severe AD. Fifty five patients with AD were treated with CsA (5 mg/kg) in a 6-week run-in period. Thereafter, patients either received CsA (3 mg/kg; n = 26) or EC-MPS (1440 mg; n = 24) during a maintenance phase of 30 weeks and there was a 12-week follow-up period. Disease activity was measured using the objective SCORAD and serum thymus and activation-regulated chemokine (TARC) levels and side effects were registered. During the first 10 weeks the objective SCORAD and serum TARC levels in the EC-MPS study arm were higher in comparison with the CsA study arm. In addition, 7 of the 24 patients treated with EC-MPS required short oral corticosteroid courses. During maintenance phase disease activity was comparable in both study arms. Side effects in both study arms were mild and transient. After study medication withdrawal, disease activity of the patients in the CsA study arm significantly increased compared with the EC-MPS study arm. The nonblinding of patients and prescriber of rescue medication are limitations. This study shows that EC-MPS is as effective as CsA as maintenance therapy in patients with AD. However, clinical improvement with EC-MPS is delayed in comparison with CsA. Clinical remission after stopping EC-MPS lasts longer compared with CsA.

The effects of PG102, a water-soluble extract from Actinidia arguta, on serum total IgE levels: a double-blind, randomized, placebo-controlled exploratory clinical study

Recent studies have reported that blocking IgE has a potentially beneficial role in the treatment of various allergic diseases. Previously, we found that PG102, a water-soluble extract prepared from the edible fruits of Actinidia arguta, can effectively reduce IgE levels using murine models. To evaluate the efficacy of PG102 at lowering levels of total IgE in asymptomatic subjects with atopy. A total of 90 asymptomatic subjects with atopy were randomized equally to a PG102 group or a placebo control group and treated for 8 weeks in a double-blind manner. Total serum IgE, eosinophilic cation protein (ECP), eotaxin, thymus, and activation-regulated chemokine (TARC), IL-4, IL-5, and IL-13 levels were measured. Eosinophil counts were determined before and after treatment, and results were compared. In addition, possible adverse reactions were thoroughly checked in this first human trial. Levels of total IgE significantly increased in the control group but showed no change in the PG102 group, and change differences between the control and PG102 groups were significant (+12.9%, vs.-5.7%, p = 0.015). Levels of ECP and eotaxin and eosinophil counts produced similar results. However, the other variables showed no significant changes after treatment. In this exploratory clinical trial, it was found that 8 weeks of treatment with PG102 effectively reduced the levels of total IgE in apparently asymptomatic subjects with atopy.

Stratum corneum TARC level is a new indicator of lesional skin inflammation in atopic dermatitis

Management of atopic dermatitis (AD) requires judging the symptoms of local skin lesions and prescribing a suitable treatment. However, no method has been established in which objective measures can be used to evaluate the severity of local symptoms. We established a method for measuring thymus and activation-regulated chemokine (TARC) levels in the stratum corneum (scTARC), and examined whether the scTARC can be used as an indicator of the severity of local skin lesions in patients with AD. Stratum corneum was obtained from patients with AD by tape-stripping, and scTARC was evaluated using a TARC-specific antibody followed by image analysis. The scTARC was examined to determine correlation with the severity of local skin lesions (the severity of erythema, edema/papule, oozing/crusts, excoriations, lichenification, and xerosis) as well as with the severity scoring of atopic dermatitis (SCORAD) index, serum TARC level, serum IgE level, serum lactate dehydrogenase (LDH) level, interleukin (IL)-4-producing T cell ratio (Th2 cell ratio), and blood eosinophil count. The scTARC was correlated with the severity of local skin lesions, especially with the erythema, edema/papule, and oozing/crusts score. The scTARC in the most severe lesions was also correlated with the SCORAD index, serum TARC level, serum IgE level, and blood eosinophil count. The scTARC was not, however, correlated with the serum LDH level and Th2 cell ratio. An immunofluorescent technique combined with tape-stripping was used to measure scTARC. The scTARC can be used as an indicator of the severity of local acute inflammation in patients with AD.

Heme oxygenase 1 attenuates the development of atopic dermatitis–like lesions in mice: Implications for human disease

Oxidative stress has been implicated in the exacerbation of atopic dermatitis (AD). We sought to investigate the pathophysiologic roles of inducible antioxidant heme oxygenase (HO) 1 in the development of AD. Serum HO-1 levels of patients with AD (n = 100) and age-matched healthy control subjects (n = 72) were determined by means of ELISA. The relationships between serum HO-1 levels and clinical severities, laboratory parameters, and cytokines/chemokines were assessed. Skin lesions of patients with AD and psoriasis were analyzed by means of immunohistochemistry. A murine AD model, DS-Nh, was used to further investigate localization and function of HO-1. Evaluation of symptoms, serum IgE and IL-18 levels, immunoblotting results, and histologic analyses of skin were performed. The effect of intraperitoneally administered hemin, a potent HO-1 inducer, or zinc protoporphyrin IX, an inhibitor of HO, was monitored. Serum HO-1 levels were significantly increased in patients with AD compared with those seen in healthy control subjects and were associated with AD disease severity. Serum HO-1 levels correlated with serum IgE, lactate dehydrogenase, IL-18, and thymus and activation-regulated chemokine levels. HO-1-expressing cells were accumulated in skin lesions of patients with AD and DS-Nh mice. Immunofluorescence of mouse skin lesions revealed that HO-1-positive cells were macrophages and dendritic cells. Treatment with hemin, but not with zinc protoporphyrin IX, attenuated the development of the skin lesions in DS-Nh mice and reduced serum IL-18 levels. HO-1 levels were increased in sera and skin lesions of patients with AD. Enhancement of HO-1 attenuated the development of skin lesions in mice, suggesting that HO-1 induction offers a promising therapeutic strategy for AD.

Changes in Plasma TARC Levels during Japanese Cedar Pollen Season and Relationships with Symptom Development

Background: Japanese cedar pollinosis (JCPsis) is an immunoglobulin E-mediated type I allergy caused by exposure to Japanese cedar pollen (JCP). Blood thymus and activation-regulated chemokine (TARC) levels are well known as an objective parameter for disease severity for several allergic disorders. The present study aims to evaluate the relationship between TARC levels and disease symptoms during the pollen season. Methods: Analysis was performed of results of symptom scores and blood parameters obtained from 42 JCPsis patients who participated in a probiotic (Bifidobacterium longum BB536) intake trial in the JCP season of 2005 (January to April), using a randomized, double-blind, placebo-controlled design. Results: Significant increases in plasma TARC levels were observed in subjects receiving placebo (p < 0.05 in February and p < 0.01 in March), but not in subjects receiving BB536. Increased plasma TARC levels were markedly greater in subjects who experienced severe symptoms and were thus excluded early from the intervention (placebo group: n = 8; BB536 group: n = 2). Significant differences were found in changes from baseline TARC levels in February and March between the subjects where treatment was terminated early and the remaining ones. Among the remaining subjects, significant positive correlations were found as regards changed values of TARC compared to baseline in March and April with symptom scores recorded in the pollen season. Conclusion: Changed values of blood TARC in the pollen season may offer promising parameters for assessing disease severity and monitoring treatment.

IL-4 and IL-13 Form a Negative Feedback Circuit with Surfactant Protein-D in the Allergic Airway Response

The innate immune molecule surfactant protein-D (SP-D) plays an important regulatory role in the allergic airway response. In this study, we demonstrate that mice sensitized and challenged with either Aspergillus fumigatus (Af) or OVA have increased SP-D levels in their lung. SP-D mRNA and protein levels in the lung also increased in response to either rIL-4 or rIL-13 treatment. Type II alveolar epithelial cell expression of IL-4Rs in mice sensitized and challenged with Af, and in vitro induction of SP-D mRNA and protein by IL-4 and IL-13, but not IFN-gamma, suggested a direct role of IL-4R-mediated events. The regulatory function of IL-4 and IL-13 was further supported in STAT-6-deficient mice as well as in IL-4/IL-13 double knockout mice that failed to increase SP-D production upon allergen challenge. Interestingly, addition of rSP-D significantly inhibited Af-driven Th2 cell activation in vitro whereas mice lacking SP-D had increased numbers of CD4(+) cells with elevated IL-13 and thymus- and activation-regulated chemokine levels in the lung and showed exaggerated production of IgE and IgG1 following allergic sensitization. We propose that allergen exposure induces elevation in SP-D protein levels in an IL-4/IL-13-dependent manner, which in turn, prevents further activation of sensitized T cells. This negative feedback regulatory circuit could be essential in protecting the airways from inflammatory damage after allergen inhalation.

Increased serum cutaneous T cell-attracting chemokine (CCL27) levels in patients with atopic dermatitis and psoriasis vulgaris

Background: Both atopic dermatitis (AD) and psoriasis vulgaris (PsV) are characterized as chronic and relapsing inflammatory skin diseases associated with various immunologic abnormalities. Cutaneous T cell-attracting chemokine (CTACK; CCL27) is a member of the CC chemokine family and a functional ligand for CC chemokine receptor 10. It is selectively expressed in skin and attracts CC chemokine receptor 10-expressing skin-homing memory T cells. The epidermal keratinocyte is a main source of CTACK, suggesting the involvement of various inflammatory skin diseases. Objective: The purpose of this investigation was to clarify whether CTACK produced by keratinocytes is detected in the sera of patients with AD and PsV and to examine the correlation between the serum CTACK levels and disease activity of patients with AD and PsV. Methods: We measured the serum CTACK levels in 50 patients with AD, 30 patients with PsV, and 22 healthy control subjects. We also divided 50 patients with AD into 3 groups (ie, those with mild, moderate, and severe disease) and compared them among 3 categories. Moreover, we compared the serum CTACK levels of patients with AD and PsV with clinical or laboratory data. Immunohistochemical staining of CTACK and IFN-induced protein of 10 kd (IP-10; CXCL10) was performed on the lesional skin of patients with AD and PsV. Results: The serum CTACK levels in patients with AD and PsV were significantly higher than those in healthy control subjects. The serum CTACK levels in patients with AD significantly correlated with scoring atopic dermatitis (SCORAD) scores, serum soluble IL-2 receptor levels, serum soluble E-selectin levels, serum thymus and activation-regulated chemokine levels, and serum macrophage-derived chemokine levels. Serum CTACK levels in patients with PsV significantly correlated with the serum IP-10 levels but not with the Psoriasis Area and Severity Index score. Immunohistochemical staining showed CTACK was strongly expressed in lesional ke-ratinocytes of patients with AD and PsV, whereas IP-10 was strongly expressed in lesional keratinocytes of patients with PsV and focally in those with AD. Conclusion: These results suggest that CTACK might be one of the important chemokines for the pathogenesis of AD and PsV. (J Allergy Clin Immunol 2003;111:592-7.)

Thymus and activation-regulated chemokine in atopic dermatitis: Serum thymus and activation-regulated chemokine level is closely related with disease activity

Background: Atopic dermatitis (AD) is a chronic and relapsing inflammatory skin disease characterized by the predominant infiltration of TH2-type cells in lesional skin. Thymus and activation-regulated chemokine (TARC/CCL17) is a chemokine that attracts CC chemokine receptor 4–positive (CCR4+) or CCR8+ cells. Objective: The purpose of this study was to investigate the participation of TARC in AD. Methods: We measured serum TARC levels in 40 patients with AD, 20 healthy control subjects, and 20 patients with psoriasis. We also examined disease activity by using SCORAD score; serum soluble E-selectin, soluble IL-2 receptor, IgE, and GM-CSF levels; and eosinophil numbers in peripheral blood, as well as correlations between TARC levels and these factors. The positivity of CCR4 of CD4+CD45RO+ cells in PBMCs was examined by using FACS analysis. Immunohistochemical staining of TARC and GM-CSF was performed in the lesional skin of patients with AD. Results: The serum TARC levels of patients with AD were significantly higher than those of healthy control subjects and patients with psoriasis. The serum TARC levels significantly correlated with eosinophil number (r = 0.61), SCORAD score (r = 0.60), and serum soluble E-selectin levels (r = 0.58) and weakly correlated with serum soluble IL-2 receptor levels (r = 0.34) in patients with AD. The TARC levels of patients with AD decreased after the treatment in accordance with the improvement of clinical symptoms. The CCR4 positivity of CD4+CD45RO+ cells in PBMCs of patients with AD was also higher than that of healthy control subjects. Immunohistochemical staining revealed that TARC was positive in ke-ratinocytes in the epidermis and in vascular endothelial cells, T cells, and dendritic cells in the dermis. Conclusion: Serum TARC levels are associated with disease activity of AD, and TARC may play an important role in the pathogenesis of AD. (J Allergy Clin Immunol 2001;107:535-41.)