Atopic dermatitis

Oral administration of Faecalibacterium prausnitzii and Akkermansia muciniphila strains from humans improves atopic dermatitis symptoms in DNCB induced NC/Nga mice

Atopic dermatitis (AD) is a common inflammatory skin disease, and its pathogenesis is closely associated with microbial homeostasis in the gut, namely the gut-skin axis. Particularly, recent metagenomics studies revealed that the abundance of two major bacterial species in the gut, Faecalibacterium prausnitzii and Akkermansia muciniphila, may play a critical role in the pathogenesis of AD, but the effect of these species in AD has not yet been elucidated. To evaluate the potential beneficial effect of F. prausnitzii or A. muciniphila in AD, we conducted an animal model study where F. prausnitzii EB-FPDK11 or A. muciniphila EB-AMDK19, isolated from humans, was orally administered to 2,5-dinitrochlorobenzene (DNCB)-induced AD models using NC/Nga mice at a daily dose of 10⁸ CFUs/mouse for six weeks. As a result, the administration of each strain of F. prausnitzii and A. muciniphila improved AD-related markers, such as dermatitis score, scratching behavior, and serum immunoglobulin E level. Also, the F. prausnitzii and A. muciniphila treatments decreased the level of thymic stromal lymphopoietin (TSLP), triggering the production of T helper (Th) 2 cytokines, and improved the imbalance between the Th1 and Th2 immune responses induced by DNCB. Meanwhile, the oral administration of the bacteria enhanced the production of filaggrin in the skin and ZO-1 in the gut barrier, leading to the recovery of functions. Taken together, our findings suggest that F. prausnitzii EB-FPDK11 and A. muciniphila EB-AMDK19 have a therapeutic potential in AD, which should be verified in humans.

Cord blood soluble Fas ligand linked to allergic rhinitis and lung function in seven-year-old children

BACKGROUND

Serum or cord blood soluble Fas ligand (FasL) has been related to asthma, allergic rhinitis, and atopic dermatitis in cross-sectional and short-term follow-up studies. However, the association of cord blood soluble FasL with long-term allergic outcomes has seldom been investigated.

METHODS

The Prediction of Allergies in Taiwanese Children birth cohort study recruited healthy newborns upon delivery. At birth, blood was collected from the umbilical cords of these children, and the cord blood soluble Fas ligand levels were measured. At the age of seven years, the allergic outcome of each child was diagnosed by pediatric allergists and pulmonologists. Tests were conducted to measure the specific immunoglobulin E, fractional exhaled nitric oxide (FeNO), and pulmonary function levels of each child.

RESULTS

Cord blood soluble FasL levels were higher in seven-year-old children with allergic rhinitis (Odds ratio [OR] = 2.41, p = 0.012) and expiratory airway obstruction (the highest forced expiratory volume in 1 second/forced vital capacity < 90%, OR = 2.11, p = 0.022). The FeNO and Dermatophagoides pteronyssinus-specific immunoglobulin E levels of seven-year-old children were positively correlated with cord blood soluble FasL levels (p = 0.006 and 0.02, respectively).

CONCLUSION

In this birth cohort, the cord blood soluble FasL levels were associated with allergic rhinitis, obstructive-type lung function, FeNO, and house dust mite sensitization in 7-year-old children. The cord blood soluble FasL level might be used as a predictor for allergic diseases in children who are 7 years old.

Increased Regulatory T Cells and Decreased Myeloid-Derived Suppressor Cells Induced by High CCL17 Levels May Account for Normal Incidence of Cancers among Patients with Atopic Dermatitis

The incidence of cancers in atopic dermatitis (AD) is not increased, although the Th2-dominant environment is known to downregulate tumor immunity. To gain mechanistic insights regarding tumor immunity in AD, we utilized CCL17 transgenic (TG) mice overexpressing CCL17, which is a key chemokine in AD. Tumor formation and lung metastasis were accelerated in CCL17 TG mice when melanoma cells were injected subcutaneously or intravenously. Flow cytometric analysis showed increases in regulatory T cells (Tregs) in lymph nodes in CCL17 TG mice with high mRNA levels of IL-10 and Foxp3 in tumors, suggesting that Tregs attenuated tumor immunity. The frequency of myeloid-derived suppressor cells (MDSCs), however, was significantly decreased in tumors of CCL17 TG mice, suggesting that decreased MDSCs might promote tumor immunity. Expression of CXCL17, a chemoattractant of MDSCs, was decreased in tumors of CCL17 TG mice. Depletion of Tregs by the anti-CD25 antibody markedly reduced tumor volumes in CCL17 TG mice, suggesting that tumor immunity was accelerated by the decrease in MDSCs in the absence of Tregs. Thus, CCL17 attenuates tumor immunity by increasing Tregs and Th2 cells, while it decreases MDSCs through reductions in CXCL17, which may work as a “safety-net” to reduce the risk of malignant tumors in the Th2-dominant environment.

Asymptomatic toddlers with house dust mite sensitization at risk of asthma and abnormal lung functions at age 7 years

Objective

To evaluate the predictive value of asymptomatic early house dust mite sensitization on allergic outcomes and pulmonary functions in 7-year olds.

Study design

The Prediction of Allergies in Taiwanese Children (PATCH) birth cohort study recruited healthy newborns at birth. At age 1.5–2 years, a Dermatophagoides pteronyssinus-specific immunoglobulin E level ≥ 0.35 kU/L was defined as early sensitization. At age 7 years, allergic outcomes were evaluated by pediatric allergists and pulmonologists, and fractional exhaled nitric oxide and pulmonary functions were measured.

Results

At age 1.5–2 years, 28.0% of toddlers were sensitized to D. pteronyssinus. Among them, 68.2% had no allergic symptoms at that time. At age 7 years, the children with early sensitization had higher risks of asthma (OR = 13.4, 95% CI, 1.2 to 153.0; P = 0.037), allergic rhinitis (OR = 10.2, 95% CI, 2.1 to 49.6; P = 0.004), and atopic dermatitis (OR = 38.5, 95% CI, 2.1 to 696.4; P = 0.014). Notably, even the asymptomatic toddlers with early D. pteronyssinus sensitization had higher probabilities of asthma (12.5% vs. 1.7%, P = 0.040), allergic rhinitis (83.3% vs. 43.1%, P = 0.009), and atopic dermatitis (20.8% vs. 0.0%, P < 0.001) at age 7 years. The asymptomatic toddlers with early sensitization also had higher exhaled nitric oxide levels and higher prevalence of airway hyperresponsiveness at age 7 years.

Conclusion

Asymptomatic toddlers with early house dust mite sensitization have higher risks of developing asthma, allergic rhinitis, atopic dermatitis, and abnormal lung functions at age 7 years.

Cord Blood Soluble CD14 Predicts Wheeze and Prolonged Cough in Young Children: The PATCH Study

BACKGROUND

Soluble cluster of differentiation 14 (sCD14) plays a role in the development and manifestation of atopic symptoms, although the results of previous studies have been inconclusive. The aim of this study is to evaluate the practical use of sCD14 as a predictive biomarker of allergy in young children.

METHODS

Children aged 0-1 year from a birth cohort in the Prediction of Allergies in Taiwanese Children (PATCH) study were enrolled. Cord blood sCD14 concentrations were measured. Pediatrician evaluation and questionnaire interviews were performed periodically until 1 year of age to determine the children's allergic and respiratory symptoms.

RESULTS

Two hundred and six 1-year-old subjects were enrolled. Wheeze was positively associated with cord blood sCD14, a family member with asthma and parental smoking. Prolonged cough was associated with cord blood sCD14, older maternal age and more siblings. In the multivariate logistic regression analysis, cord blood sCD14 was the only independent predictive biomarker for wheeze and prolonged cough by 1 year of age. Every 100-ng/ml increase in cord blood sCD14 resulted in a 1.56-fold higher risk of developing wheeze and a 1.62-fold higher risk of prolonged cough in children by 1 year of age.

CONCLUSIONS

Cord blood sCD14 may be a useful biomarker for predicting infant wheeze and prolonged cough by 1 year of age.

Histamine differentially regulates the production of Th1 and Th2 chemokines by keratinocytes through histamine H1 receptor

Histamine is a biological amine that plays an important role in allergic responses. However, the involvement of histamine signaling in late allergic responses in the skin is poorly understood. Therefore, we attempted to investigate the involvement of histamine signaling in late allergic responses, especially in keratinocytes (KCs). HaCaT KCs and normal human KCs (NHKs) predominantly expressed histamine H1 receptor (H1R) and H2 receptor (H2R). Histamine suppressed tumor necrosis factor α (TNF-α)- and interferon-γ (IFN-γ)-induced production of CC chemokine ligand 17(CCL17), a type 2 T-helper (Th2) chemokine, by HaCaT KCs. It suppressed the phosphorylation of p38 mitogen-activated protein (MAP) kinase, but not that of extracellular signal-regulated kinases (ERKs), and TNF-α- and IFN-γ-induced nuclear factor κB (NFκB) activity. In contrast, histamine enhanced the production of CXC chemokine ligand 10 (CXCL10), a Th1 chemokine, by TNF-α- and IFN-γ-stimulated HaCaT KCs and NHKs. TNF-α- and IFN-γ-induced CXCL10 production was upregulated by suppression of p38 MAP kinase or NF-κB activity, which could explain histamine involvement. We concluded that histamine suppresses CCL17 production by KCs by suppressing p38 MAP kinase and NF-κB activity through H1R and may act as a negative-feedback signal for existing Th2-dominant inflammation by suppressing CCL17 and enhancing CXCL10 production.

Eczema and sleep and its relationship to daytime functioning in children

Chronic childhood eczema has significant morbidity characterised by physical discomfort, emotional distress, reduced child and family quality-of-life and, of particular note, disturbed sleep characterised by frequent and prolonged arousals. Sleep disturbance affects up to 60% of children with eczema, increasing to 83% during exacerbation. Even when in clinical remission, children with eczema demonstrate more sleep disturbance than healthy children. Notably, disturbed sleep in otherwise healthy children is associated with behavioural and neurocognitive deficits. Preliminary evidence suggests that disturbed sleep in children with eczema is also associated with behavioural deficits while the impact on neuropsychological functioning remains unexplored. In conclusion, a disease which affects up to 20% of children in some countries and may produce long-term behavioural and neurocognitive deficits merits further evaluation using standardised tests of sleep, behaviour and neurocognition.

High abundances of neurotrophin 3 in atopic dermatitis mast cell

Background

Neurotrophin 3 (NT-3) is a member of the neurotrophin family, a group of related proteins that are known to regulate neuro-immune interactions in allergic diseases. Their cellular sources and role in the recruitment of mast cell precursors in atopic dermatitis have not been characterized in detail so far.

Objective

Characterize NT-3 on a transcriptional and translational level in individuals with atopic dermatitis with special focus on mast cells.

Methods

To meet this objective NT-3 levels in the serum of AD patients were measured, the effect of NT-3 on keratinocytes was evaluated and the gene expression and regulation assessed using ELISA, immunohistochemistry and RNA quantification.

Results

Systemic levels of NT-3 were found to be higher in individuals with AD as compared to healthy controls. A distinct genetic expression was found in the various cells of the skin. In lesional mast cells of individuals with atopic dermatitis an increased amount of NT-3 was apparent. Functional in vitro experiments demonstrated that NT-3 stimulation led to a suppression of IL-8 secretion by HaCat cells.

Conclusion

These findings could imply a role for NT-3 in the pathogenesis of allergic skin diseases.

Cell type-specific regulation of brain-derived neurotrophic factor in states of allergic inflammation

BACKGROUND

Brain-derived neurotrophic factor (BDNF) is a molecule influencing neuronal proliferation and differentiation. In states of allergy, it may orchestrate inflammatory changes by linking the immune system with the nervous system. Because the precise regulation of gene transcription in mast cells MCs is not clear, the present studies assessed the gene regulation of BDNF in this inflammatory cell type.

METHODS

Transcriptional expression of BDNF in human skin was studied in isolated cells using RT-PCR. In situ lesional MC BDNF protein expression was analysed by immunohistochemistry and related to the differential staining of MCs and functional effects of BDNF on HaCaT keratinocytes.

RESULTS

BDNF mRNA expression was found in isolated human skin MCs, keratinocytes, and fibroblasts. Also, low levels were found in endothelial cells and melanocytes. BDNF protein expression was found in situ in lesional and non-lesional MCs. A significantly decreased expression of BDNF protein was found in atopic dermatitis lesional MCs when compared with control MC expression. Functional in vitro experiments demonstrated that a decrease in BDNF stimulation led to increased secretion rates for stem cell factor and IL-8 in HaCaT keratinocytes.

CONCLUSION

The demonstration of a decreased level of BDNF gene transcription in lesional MCs points to a differential regulation of MC-released neutrotrophins in cutaneous allergic inflammation. Topically administered neurotrophin receptor-modulating compounds should be receptor target specific and not universally acting in diseases such as atopic dermatitis or allergic asthma.

Action of a silk fabric treated with AEGIS in children with atopic dermatitis: a 3-month trial

Irritation of the skin of patients with atopic dermatitis by contact with rough fibres of synthetic or woollen clothes is well known. Therefore, it has been recommended that patients should wear cotton clothes. However, cotton also consists of rough fibres able to irritate the skin, whereas silk is characterized by smooth fibres without irritating potential. The aim of our study was to evaluate the clinical effect of Dermasilk- a special silk fabric (sericin-free silk treated with AEGIS AEM5772/5 which has antibacterial properties) - in children with atopic dermatitis. A total of 22 children with mild-to-moderate atopic dermatitis were recruited for a study period of 3 months. All of them received three different tube-fabrics - Dermasilk, sericin-free silk fabric without AEGIS AEM 5772/5 and cotton, covering the cubital region. Patients were advised to wear the Dermasilk fabric all day long during the whole study period on one arm, whereas the sericin-free AEGIS-free silk tube had to be used during the first 2 wk only on the other arm followed by the use of the cotton tube for the rest of the study period. Evaluation of the local SCORAD score was carried out at the beginning of the study, after 2, 4, 8 and 12 wk. A significant reduction of the local SCORAD index of the Dermasilk covered arm was observed after 4, 8 and 12 wk in comparison with the cotton-covered arm score [median (quartile 1-quartile 3)] 6.5 (5-8) vs. 8 (7-9), p < 0.002; 6 (5.25-7.75) vs. 8 (7-9), p < 0.0001; and 6 (5-6) vs. 8 (7.25-10), p < 0.0001. The use of Dermasilk has a significant beneficial effect in atopic dermatitis because of the non-irritating properties of silk as well as the antibacterial capacity of AEGIS AEM 5772/5.

CCL17 transgenic mice show an enhanced Th2-type response to both allergic and non-allergic stimuli

CC chemokine ligand (CCL)17 is implicated in the pathogenesis of atopic dermatitis (AD). To study the effect of CCL17 produced by keratinocytes (KC) during inflammation, we created transgenic (Tg) mice in which CCL17 is overexpressed in KC. Th2-type contact hypersensitivity (CHS) was enhanced and Th1-type CHS was suppressed in these mice. Increased numbers of CC chemokine receptor (CCR)4(+) cells and mast cells infiltrated in Tg mice. Levels of IL-4 mRNA were higher and those of IFN-gamma mRNA were lower in both acute and chronic CHS. Higher levels of serum IgE were observed after CHS. Numbers of CCR4(+) cells among PBMC were increased in Tg mice challenged acutely on the trunk. Chronic irritation with croton oil induced dermatitis and an elevation of serum IgE levels. Tg mice showed enhanced ear swelling after tape stripping. CCL17 was thought to modify the inflammation caused by sensitizing reagents as well as irritant reagents by attracting CCR4(+) cells into the lesional skin and creating a Th2-dominant condition. AD-like conditions such as increased number of mast cells and elevated levels of serum IgE were observed. Thus, CCL17 may participate in the pathogenesis of skin diseases such as AD by regulating both allergic and irritant inflammation.

Increased susceptibility to Staphylococcus aureus colonization of the skin of the NOA mouse: a potentially useful animal model for evaluating antiseptic effects

Isolation of bacteria from wet skin lesions was attempted using Naruto Research Institute Otsuka Atrichia (NOA) mice, which develop such lesions spontaneously at a high rate. As a result, Staphylococcus aureus was demonstrated to have colonized the wet skin lesions at high density. In addition, the isolated S. aureus was found to be similar to the strain of S. aureus thought to colonize the eczematous lesions seen in humans with atopic dermatitis. Furthermore, a survey of the S. aureus colonization status of NOA mice with no wet skin lesions confirmed colonization at higher density than in HR-1 mice as control, indicating that the skin of the NOA mouse has the novel characteristic of increased susceptibility to S. aureus colonization. Thus, by using changes in S. aureus counts as an index, the NOA mouse can be expected to serve as a useful animal model for evaluating the effects of topical antiseptics. The antiseptic effects of an ointment and a lotion containing chlorhexidine gluconate were confirmed using this animal model.

Acute allergic reactions in children with AEDS after prolonged cow's milk elimination diets

BACKGROUND

Food allergy is not always correctly diagnosed in children with atopic eczema dermatitis syndrome (AEDS) and treatment with an avoidance diet is not without danger.

METHODS

After admission to our clinic, 11 children with a prolonged cow's milk (CM) elimination diet because of AEDS and sensitization underwent double-blind placebo-controlled food challenge (DBPCFC). Retrospectively, the exposure to CM, sensitization and reactions to accidental ingestion were carefully documented. The DBPCFC was used to evaluate the childrens' current status.

RESULTS

Before the elimination period (median 2.3 years; started before the admission) all 11 children with AEDS were sensitized and had ingested CM (four bottle-fed; seven breast-fed without CM diet of the mother) without the development of acute reactions. The diagnosis of CM allergy was not confirmed by DBPCFC previously. After elimination the AEDS had not improved, but nevertheless the diet was continued. During the elimination period, eight of 11 children developed severe acute allergic reactions to CM after accidental ingestion. In evaluation, in our clinic all 11 children experienced acute allergic reactions to CM during DBPCFC.

CONCLUSION

There is a considerable chance of developing acute allergic reactions to CM after elimination in children with AEDS without previous problems after CM intake.

Role of substance P in stress-derived degranulation of dermal mast cells in mice

BACKGROUND

The interaction between nerves and mast cells can effect regulation of the immune system and inflammatory responses. Recent studies have shown that various stressors can induce degranulation of dermal mast cells in animals.

OBJECTIVES

This study was conducted to confirm that substance P (SP) was involved in the degranulation of dermal mast cells in stress conditions.

METHODS

Using a communication box system, foot shock stress (FS) and psychological stress (PS) were administered to mice and the degranulation rate of dermal mast cells, the number of SP-positive nerve fibers and changes in SP content were determined. The inhibitory effect of a non-peptide NK1-receptor antagonist on these changes was investigated.

RESULTS

Both FS and PS significantly enhanced the degranulation of dermal mast cells and increased the number of SP-positive nerve fibers. FS significantly decreased dermal SP content whereas SP was increased by PS. These changes were inhibited by intraperitoneal injection of NK(1) receptor antagonist.

CONCLUSIONS

It was considered that SP released from the nerve ending, had an important role in the degranulation of dermal mast cells. Results of this study suggest that the tachykinin receptor antagonist exhibited an inhibitory effect on aggravated stress-induced dermatitis.

The relationship between serum levels of total IgE, IL-18, IL-12, IFN-gamma and disease severity in children with atopic dermatitis

Studies about the role of cytokines on the immunopathogenesis of atopic dermatitis (AD) are generally based on in vitro observations and this role has not been completely clarified yet. Serum levels of total IgE, IL-18, IL-12, IFN-gamma and the relationship between these parameters and disease severity, determined using the SCORAD index, in a group of atopic patients were investigated in this study. Serum levels of total IgE were measured by the nephelometric method and serum levels of IL-18, IL-12/p40 and IFN-gamma were measured by ELISA method. Serum levels of total IgE and IL-18 were found significantly higher in study group than in controls (P<.001). There was no statistically significant difference between patients and controls in respect of serum levels of IL-12/p40 (P = .227). A statistically significant relationship between SCORAD values and serum levels of total IgE (P < .001), IL-18 (P < .001), and IL-12/p40 (P < .001) was determined. These results show that serum levels of IL-18 can be a sensitive parameter that importantly correlates with clinical severity of AD, can play a role in the immunopathogenesis of AD, and furthermore may be used in the diagnosis and follow-up of the disease in addition to other parameters.

Gene expression and regulation of nerve growth factor in atopic dermatitis mast cells and the human mast cell line-1

The gene expression and regulation of nerve growth factor (NGF) in atopic dermatitis (AD) and the human mast cell line (HMC)-1 was investigated at the molecular level. NGF-stimulation of HMC-1 cells resulted in increases in tryptase activity and histamine contents, paralleled by an increase of tryptase and histamine at the transcriptional level. Also, an increased expression of NGF was found in AD lesions, in association with increased systemic NGF plasma levels. Further cutaneous sources for increased NGF levels were keratinocytes and fibroblasts. These findings demonstrate an increased expression of NGF in AD and effects on tryptase and histamine. Mast cells may be major mediators of neurotrophin effects in AD.

Dietary modification of atopic disease: Use of probiotics in the prevention of atopic dermatitis

The increased prevalence of atopic diseases, atopic dermatitis, allergic rhinitis, and asthma has been described as an epidemic. New approaches in the fight against allergic diseases are called for, the target being the persistence of the atopic T helper 2-skewed immune responder pattern beyond infancy. Atopic dermatitis, the earliest of these conditions, might act as a portal for the development of IgE-mediated atopic manifestations. Abundant evidence implies that specific strains selected from the healthy gut microbiota exhibit powerful antipathogenic and anti-inflammatory capabilities, and several targets for the probiotic approach have emerged in atopic dermatitis: degradation/structural modification of enteral antigens, normalization of the properties of aberrant indigenous microbiota and of gut barrier functions, regulation of the secretion of inflammatory mediators, and promotion of the development of the immune system. Better understanding of the effects of different probiotic strains and deeper insight into the mechanisms of the heterogeneous manifestations of atopic disease are needed for the validation of specific strains carrying anti-allergic potential.

Development of Dry Skin in the NOA Mouse Under Individual Housing Conditions: A Potentially Useful Animal Model for Evaluating Moisturizing Effects

In a previous study, we reported the development of grossly observable dry skin in all of the Naruto Research Institute Otsuka Atrichia (NOA) mice that were housed individually. In the present study, dermal physiological function tests were conducted and the usefulness of this dry skin model for evaluating the efficacy of topical moisturizers was assessed. As a result, we have confirmed a marked reduction in the water content of the stratum corneum in these animals. Therefore, the development of dry skin in the NOA mouse strain under individual housing conditions may be expected to serve as a useful animal model for evaluating topical moisturizers. Specifically, the water content of the stratum corneum was restored in proportion to the oil content of the ointment base used to treat the animals, and the moisturizing effects of urea were confirmed in animals treated with urea-containing ointment. In addition, when the animals that had been housed individually were returned to group housing conditions, the water content of the stratum corneum was restored, with a corresponding improvement in dry skin. This finding suggests that socio-psychological factors are involved in the etiology of dry skin in individually housed NOA mice.

Effects of Housing Conditions on the Development of Wet Skin Lesions in the NOA Mouse

The effects of housing on the onset time and prevalence of wet skin lesions were investigated in NOA mice, which spontaneously develop these lesions at a high rate. Wet skin lesions developed earliest in mice that were housed individually. For mice that were housed in groups, the lesions developed earlier in mice with non-littermate group housing than in mice with littermate group housing. The prevalence of lesions was in the following order: individual housing > non-littermate group housing > littermate group housing. These results suggest that socio-psychological factors are involved in the etiology of wet skin lesions in the NOA mouse. Under individual housing conditions, two other novel characters of the NOA mouse were also observed, specifically, development of dry skin and wet skin lesions at the tail root. These characteristics developed early and with high prevalence and were easily observed on external examination. Therefore, these novel characteristics observed in NOA mice are potential markers of the psychological state of the animals.

Mast cells and vasculature in atopic dermatitis--potential stimulus of neoangiogenesis

BACKGROUND

Atopic dermatitis skin lesions are characterized by inflammatory changes and epithelial hyperplasia requiring angiogenesis. As mast cells may participate in this process via bidirectional secretion of tissue-damaging enzymes and pro-angiogenic factors, the present study aimed to assess the occurrence and possible function of mast cells in the papillary dermis and in epidermal layers of atopic dermatitis lesions.

METHODS

Semi-thin and serial sections in combination with immunohistochemistry, histochemistry and proliferating cell nuclear antigen (PCNA)-activity assays were used and related to epidermal thickness and targeted gene expression studies.

RESULTS

Mast cells were located in the papillary dermis and migrated through the basal lamina into the epidermis of atopic dermatitis lesions. An increased PCNA-activity in cells of superficial epidermal layers indicated an activation of keratinocytes and stimulation of endothelial growth. Only approximately 30% of the papillary mast cells stained with the tryptase were toluidin-blue-positive, and approximately 80% were chymase positive. A high number of mast cells expressed c-kit. Most papillary and epidermal mast cells were localized close to endothelial cells. Vascular expression of endoglin (CD105) demonstrated neoangiogenic processes. Mast cells stimulation led to the expression of proangiogenic factors. Also, gene expression of tissue-damaging factors such as matrix metalloproteinases was increased.

CONCLUSIONS

These data suggest that in atopic dermatitis, mast cells are abundantly localized close to and within the epidermis where they may stimulate neoangiogenesis. Via the new vessels, inflammatory cells, together with complement components and antibodies, can be transported to the epidermis to aid in the defense against environmental antigens and to maintain chronic inflammation.

Immunoglobulin E- (IgE) and non-IgE-mediated reactions in the pathogenesis of atopic eczema/dermatitis syndrome (AEDS)

AEDS is a chronic, relapsing, highly pruritic inflammatory skin disease that commonly begins in childhood. Two forms of this disorder exist, i.e. an allergic (extrinsic) form and a nonallergic (intrinsic) form. There are clear genetic, humoral and cellular differences between the allergic and nonallergic forms of AEDS. The allergic variants express local IgE production in affected tissue and both allergic and nonallergic triggers play a major role in the expression of disease. The role of allergens is very important in the immunopathogenesis of AEDS. Nonimmunological triggers play a secondary modulatory role often hampering treatment effort and optimal response to therapeutic efforts.

Nerve growth factor and substance P are useful plasma markers of disease activity in atopic dermatitis

BACKGROUND

Neurogenic components, such as neurotrophic factors and neuropeptides, are probably involved in the pathogenesis of atopic dermatitis (AD) via the neuroimmunocutaneous system. Numerous in vitro and in vivo studies have shown that nerve growth factor (NGF), the best-characterized member of the neurotrophin family, modulates the synthesis of the neuropeptide substance P (SP), both of which may be associated with the pathogenesis of human allergic diseases.

OBJECTIVES

To evaluate the levels of NGF and SP in the plasma of patients with AD and to examine their possible correlation with disease activity.

METHODS

We measured plasma levels of NGF by an immunoenzymatic assay and of SP by aradioimmunoassay in 52 patients with AD, and compared them with 35 normal non-atopic controls. The severity of the disease in AD patients was evaluated using validated clinical scoring systems.

RESULTS

Patients with AD had significant increases in plasma levels of NGF and SP compared with controls (P < 0.0005 and P < 0.0001, respectively). A positive correlation between the plasma levels of NGF and SP was found in AD patients (correlation coefficient, Cc = 0.920, P < 0.0001). There was a significant correlation of plasma NGF and SP levels with disease activity evaluated using three different scoring systems: the grading system of Rajka and Langeland (P < 0.001 and P < 0.01, respectively), the objective Severity Scoring of AD (Cc = 0.656, P < 0.005 and Cc = 0.752, P < 0.0005, respectively) and the Eczema Area and Severity Index (Cc = 0.740, P < 0.001 and Cc = 0.765, P < 0.005, respectively).

CONCLUSIONS

These data represent the first reported evidence of increased plasma levels of NGF and SP in an allergic human skin disease. They suggest that these neurogenic factors systemically modulate the allergic response in AD, probably through interactions with cells of the immune-inflammatory component. In addition, NGF and SP may be useful markers of disease activity in patients with AD.

Lack of association between atopic eczema/dermatitis syndrome and polymorphisms in the promoter region of RANTES and regulatory region of MCP-1

BACKGROUND

Chemokines play an important role in the pathophysiology of atopic eczema/dermatitis syndrome (AEDS) and allergy. Recently polymorphisms in the promoter region of RANTES (regulated on activation normal T cell expressed and secreted) and in the gene regulatory region of MCP-1 (monocyte chemoattractant protein-1) have been found, which increase the expression of these chemokines. The - 403A allele of the RANTES promoter region was found associated with AEDS in German children. We investigated whether the presence of these polymorphisms was associated with AEDS or allergy in Hungarian children.

METHODS

One hundred and twenty-eight children with AEDS, 102 allergic children without AEDS and 303 children of comparable ages without allergic disorders were screened for genotype with a PCR-based assay.

RESULTS

There were no significant differences in the frequency of these polymorphisms, or in the distribution of genotypes between the groups. The total IgE concentration, the white blood cell count and the blood eosinophil cell count did not differ between the genotypes.

CONCLUSION

In this cohort of Hungarian children there was no association between - 28G, and - 403A alleles in the RANTES promoter, - 2518G polymorphism in the distal regulatory region of the MCP-1 and AEDS, or allergy.

CD35 expression on peripheral blood granulocytes of patients with atopic dermatitis

We examined CD35 expression on granulocytes from 45 patients with atopic dermatitis (AD) (male, 21, female, 24) and 25 age and sex-matched controls (male, 15; female, 10). There was no significant difference in the peripheral blood neutrophil count between AD patients and controls, whereas the eosinophil count in AD patients was significantly higher than that of controls. The percentages of CD35 positive eosinophils and neutrophils were determined by using two-color flow cytometric analysis. As regards eosinophils, we found CD35 expression from AD patients to be lower than that of controls (P < 0.05), but there was no correlation between the CD35 expression and disease severity. In contrast, the CD35 expression on neutrophils from AD patients was much lower than that of controls (P < 0.005). Furthermore, CD35 expression on neutrophils of severe AD group was significantly higher than that of the mild AD group (P < 0.05). This suggests that the CD35 expression of neutrophils but not eosinophils reflects disease severity in AD patients and the CD35 expression on neutrophils in AD patients may associate with susceptibility to bacterial infection.

High serum levels of additional IL-18 forms may be reciprocally correlated with IgE levels in patients with atopic dermatitis

We established an ELISA system for determination of as yet unidentified species of interleukin 18 (IL-18), named IL-18 type 2, in human serum. Serum IL-18 levels and their effect on IgE levels were examined in 18 patients with atopic dermatitis (AD) with no other allergic symptoms. Three of these patients showed high IL-18 type 2 concentrations (25-100 ng/ml) in their blood serum, and this IL-18 type 2 was detectable only with our established ELISA system. In contrast, the level of the conventional form of IL-18 (type 1) was found to be 50-400 pg/ml in all patients by the commercially available ELISA. The levels of type 1 IL-18 showed no correlation with those of type 2 and approximately 2-fold higher in AD patients than in normal subjects. IL-12 p40 and IgE levels were correlated in the patients with no IL-18 type 2, and interestingly, relatively low IgE concentrations were detected in the three IL-18 type 2-positive patients. They showed considerable levels of IL-12 p40 unlike normal subjects. The IFNgamma-inducing activity of IL-18 type 2 was >100-fold less potent by weight ratio than that of a recombinant 'active' IL-18 preparation, even after the treatment with Caspase 1. Although the relationship between AD and serum IgE levels is not clear cut, IL-18 type 2 appears to play some roles in the Th2-polarization involving IgE production in association with immune responses occurring in local inflammatory milieu such as atopic lesions.

IFN-gamma production in response to IL-18 or IL-12 stimulation by peripheral blood mononuclear cells of atopic patients

BACKGROUND

Several studies have shown that interleukin (IL)-4 and interferon-gamma (IFN-gamma) are important for the regulation of immunoglobulin E (IgE) production and that IL-18 and IL-12 induce IFN-gamma.

OBJECTIVE

IFN-gamma production in response to IL-18 or IL-12 stimulation was investigated in peripheral blood mononuclear cells (PBMCs) of atopic patients with various levels of serum IgE.

METHODS

Cytokine production from PBMCs was measured following stimulation with a non-specific stimulator (phytohemagglutinin: PHA), IL-18 or IL-12 in 12 healthy controls and 26 atopic patients with various serum IgE levels.

RESULTS

IFN-gamma production by IL-18-stimulated PBMCs was positively correlated with IFN-gamma production by IL-12-stimulated PBMCs (P < 0.05). However some atopic patients showed discrepancy between the levels of IFN-gamma production stimulated by IL-12 and by IL-18.

CONCLUSIONS

The results shown here suggest the presence of abnormalities in the IL-12 and/or IL-18 signalling pathways, such as genetic defects in the atopic patients.

Interleukin-15 expression in cutaneous T-cell lymphoma (mycosis fungoides and Sezary syndrome)

BACKGROUND

Cytokines are of potential importance in the pathogenesis of cutaneous T-cell mediated disorders, including cutaneous T-cell lymphoma (CTCL).

OBJECTIVES

To compare interleukin (IL)-15 expression in certain inflammatory cutaneous diseases, with that in CTCL (mycosis fungoides and Sézary syndrome).

METHODS

IL-15 mRNA and protein expression were examined by in situ hybridization and immunohistochemistry, respectively, on formalin-fixed, paraffin-embedded biopsies of normal human skin, atopic dermatitis, psoriasis, parapsoriasis and CTCL.

RESULTS

Despite similar expression of IL-15 mRNA, we found differences in IL-15 protein expression between normal human skin, atopic dermatitis and psoriasis on the one hand, and parapsoriasis and CTCL on the other. IL-15 protein expression was not detected in normal human skin, atopic dermatitis or psoriasis, but was detected, mainly at low levels but in a few patients at higher levels, in epidermal keratinocytes in parapsoriasis, mycosis fungoides and Sézary syndrome.

CONCLUSIONS

Induction of keratinocyte IL-15 expression appears to be a feature of CTCL. The factors stimulating such an expression remain unknown.

Reduction of serum interleukin-5 levels reflect clinical improvement in patients with atopic dermatitis

Cytokines, in particular IL-4 and IL-5, regulate IgE synthesis and eosinophil activation in atopic dermatitis (AD). To elucidate whether the serum levels of IL-4 and IL-5 are related to the serum IgE level, eosinophilia, or clinical severity of the disease, 25 cases with AD were studied. Blood samples were isolated from two groups of donors: 1) patients with AD (n = 25); 2) non-allergic individuals (NA, n = 20) with serum IgE levels below 100 IU/ml and with blood eosinophil counts below 250/microliter. Each parameter was evaluated at least twice in AD patients at the beginning of the study and after 4, 8 or 12 weeks of treatment. IL-4 was hardly detected in AD and NA, but IL-5 was increased (> 10 pg/ml) in most cases (22/25) of AD group with 513.6 pg/ml as the mean. AD with normal serum IgE levels exhibited increased levels of IL-5, whereas AD with high serum IgE levels did not necessarily have elevated IL-5 levels. The IL-5 level tended to change in parallel with the clinical severity in each AD case, although the level itself was not correlated with the clinical severity per se. A significant decrease of IL-5 was observed in AD when the clinical severity decreased. Eosinophils also decreased along with the improvement of AD, whereas the serum level of IgE did not change during the observation period. Our results suggest that IL-5 is involved in the regulation of clinical courses of AD and that its kinetics at the serum level reflects the clinical activity of AD.

Differences in antigen-specific T-cell responses between infants with atopic dermatitis with and without cow's milk allergy: relevance of TH2 cytokines

BACKGROUND

Cow's milk is the most important food antigen in infancy and may lead to acute cutaneous symptoms and atopic dermatitis (AD). The role of circulating allergen-specific T cells in the pathogenesis of food-allergic skin symptoms is still under investigation.

OBJECTIVE

This study was designed to analyze the cow's milk protein (CMP)-specific T-cell response at the clonal level in infants with AD and cow's milk allergy (CMA) in comparison with infants with AD without CMA.

METHODS

We used an antigen-specific culturing system with autologous B cells as antigen-presenting cells to establish CMP-specific T-cell clones derived from PBMCs in infants with AD. T-cell reactivity, measured by using a lymphocyte stimulation test, and cytokine production, measured by using ELISA, was compared between infants with AD with and without CMA.

RESULTS

Both infants with and without allergy to cow's milk had a CMP-specific T helper cell response directed against the major proteins in milk. Analysis of antigen-specific cytokine production showed that this response was T(H)2 skewed in infants with CMA, with production of high levels of IL-4, IL-5, and IL-13. In contrast, infants without CMA had a T(H)1-skewed response, with high levels of IFN-gamma and low levels of IL-4, IL-5, and IL-13.

CONCLUSION

These data confirm for the first time at the clonal level that food allergy in infants with AD is associated with production of T(H)2 cytokines by circulating antigen-specific CD4(+) T cells, whereas tolerance to food antigens is associated with low levels of these cytokines. This suggests a key role for the T helper cell-derived T(H)2 cytokines in food allergy-related skin symptoms.

Pattern of skin disease at the Ethio-Swedish pediatric hospital, Addis Ababa, Ethiopia

Although skin diseases are common in children, only a very few prospective studies are available, in the literature, mainly from developed countries. This work reports the pattern of skin diseases in a tertiary referral hospital in Addis Ababa, Ethiopia, from June 1995 to July 1997. A total of 1000 consecutive new pediatric patients, ages 0-12 years, were studied. The male:female ratio was 1:1. Allergic skin diseases were most frequently found (55%), followed by infections (33%) and photodermatosis (8%). Of the allergic skin diseases, atopic dermatitis was the most prevalent (47%), followed by seborrheic dermatitis (17.4%).

Evidence for increased expression of eotaxin and monocyte chemotactic protein-4 in atopic dermatitis

BACKGROUND

Atopic dermatitis (AD) is a chronic inflammatory skin disease associated with tissue eosinophilia and the activation of T lymphocytes. The novel eosinophil chemoattractants, eotaxin and monocyte chemotactic protein (MCP)-4, are up-regulated at sites of allergic inflammation, yet their contribution to the pathophysiologic mechanisms of AD remains to be determined.

OBJECTIVE

We sought to investigate the expression of eotaxin and MCP-4 in acute and chronic lesions from patients with AD and to determine their relationship to the numbers of resident inflammatory cells.

METHODS

With use of in situ hybridization, the expression of eotaxin and MCP-4 messenger RNA (mRNA) in skin biopsy specimens from patients with acute and chronic AD skin lesions was compared with that of uninvolved skin from these patients and skin from healthy volunteers.

RESULTS

There was a constitutive expression of eotaxin and MCP-4 mRNA in skin biopsy specimens from healthy subjects. Positive signal for chemokine mRNA was observed both within the epidermis and inflammatory cells (macrophages, eosinophils, and T cells) of the subepidermis in AD skin lesions. Within the subepithelium acute and chronic skin lesions exhibited a significant increase in the numbers of eotaxin and MCP-4 mRNA-positive cells compared with uninvolved skin (P <.01), whereas the numbers of eotaxin and MCP-4 mRNA-positive cells were significantly higher in chronic AD compared with acute AD skin lesions (P <.005, P <.001, respectively). Correlations were observed between the expression of eotaxin and MCP-4 mRNA and the presence of eosinophils and macrophages, respectively, in AD lesions (r(2) = 0.84, r(2) = 0.94).

CONCLUSION

There is an increased expression of eotaxin and MCP-4 in acute and chronic lesions, suggesting that these chemotactic factors play a major role in the pathophysiologic mechanisms of AD.

Mast cell density and subtypes in the skin of dogs with atopic dermatitis

Skin biopsies from seven dogs with atopic dermatitis and 13 dogs with no clinical or histological evidence of skin diseases were examined. The study of the atopic dogs included 11 biopsy samples of nonlesional skin and 15 samples of lesional skin. One section of each tissue sample was stained with haematoxylin and eosin and another with toluidine blue to demonstrate the sulphated acid glycosaminoglycans in mast cell (MC) granules. To investigate MC subtypes, the MC-specific proteases tryptase and chymase were examined by a double enzyme-immunohistochemical staining technique. With the double labelling technique a significantly lower mast cell density was demonstrated in lesional (P = 0.0023) and nonlesional (P = 0.0004) skin samples of the atopic dogs than in the skin of control dogs. In the dermis of control dogs, a median mast cell density of 31.2 MC/mm2 was detected with the toluidine blue staining method and of 27.5 MC/mm2 with the double labelling technique. In lesional dermis of atopic dogs 29.8 MC/mm2 were seen with toluidine blue while only 12.4 MC/mm2 were stained with the double labelling method (P = 0.0027). A similar difference was observed in nonlesional dermis samples, in which a mast cell density of 23.3 MC/mm2 was detected with toluidine blue but only 6.4 MC/mm2 with the double labelling method (P = 0.0127). The data provide evidence that mast cell granule heterogeneity exists in the dog and suggests that degranulation occurs selectively, depending on the pathological condition of the canine skin. Further investigations on the pathophysiological role of mast cell subtypes may help to elucidate the pathogenesis of atopic dermatitis.

Food allergy

Food allergies are immunologic reactions to food allergens or food components. Several distinct clinical entities fall under this term, including immediate-in-time allergic reactions, which are IgE-dependent and involve mast cells and basophils, and delayed-in-time reactions to foods, such as food-induced enterocolitis, which involve additional effector systems. Most food allergies are precipitated by a small number of foods. The diagnosis of these diseases depends on history, physical examination, specific diagnostic assays, and oral food challenge. The differential diagnosis of these diseases is extensive. Treatment of food allergies relies on identification of the food substance that induces the reaction and subsequent avoidance measures. When an individual inadvertently consumes food to which he or she is sensitized, pharmacologic treatment is available.

Reduced interferon gamma production by antigen-stimulated cord blood mononuclear cells is a risk factor of allergic disorders--6-year follow-up study

BACKGROUND

It is not sufficient to predict 'high allergic risk newborns' on the basis of increased IgE concentrations of cord blood alone, because a raised cord blood IgE concentration is specific but not sensitive in the prediction of the development of allergic disorders. Warner et al. have reported that interferon gamma (IFN-gamma) production by allergen-triggered cord blood cells is a predictor of atopic eczema, based on the 1-year follow-up study.

OBJECTIVE

We examined whether IFN-gamma production by antigen-stimulated cord blood mononuclear cells (CBMCs) is a risk factor of allergic disorders, based on the 6-year follow-up study.

METHODS

The relationships among cord blood IgE concentrations, IFN-gamma and interleukin-2 (IL-2) productions by antigen-stimulated CBMCs, and the development of allergic disorders in 21 infants for 6 years were investigated.

RESULTS

Atopic dermatitis, atopic dermatitis and allergic rhinitis, or atopic dermatitis and bronchial asthma developed in seven of 21 subjects. The maximal IFN-gamma concentration in culture supernatants of ovalbumin (OA) or bovine serum albumin (BSA) stimulated CBMCs in infants who developed allergic disorders was significantly lower (P < 0.01) than that in infants who did not develop any allergic disorders. In contrast, the maximal IL-2 concentration in culture supernatants of OA- or BSA-stimulated CBMCs in infants who developed allergic disorders was not lower than in infants who did not develop any allergic disorders. Moreover, the IFN-gamma concentrations were negatively correlated with cord blood IgE concentrations.

CONCLUSION

Reduced IFN-gamma production by antigen-stimulated CBMCs is a risk factor of allergic disorders.

Clinical course of atopic dermatitis in Japanese patients

We conducted a questionnaire study of 117 patients, who had first consulted the Department of Dermatology Kumamoto University Hospital 20 or 30 years ago, regarding the clinical course of atopic dermatitis (AD). Forty-one patients responded to the questionnaire. Seventeen patients (41.4%) had recovered and 24 patients (58.6%) still had AD. The AD had resolved in 12 of 13 (92.2%) with mild disease severity, four of 18 (22.2%) with moderate severity and one of ten (10%) with severe disease. The outcome was significantly better in the mild group than in the moderate or severe group (chi2=15.5, P=0.0008/chi2=14.8, P=0.00012, respectively). The resolution of the disease was not correlated with the sex of patient, age at onset, period of disease or family history.

In vivo expression of cytokine receptor mRNA in atopic dermatitis

BACKGROUND

Atopic dermatitis (AD) is a chronic inflammatory skin disease with immunopathologic features that vary depending on the duration of the lesion. Acute lesions are associated with a T-cell infiltrate and a high expression of IL-4 mRNA compared with chronic lesions, uninvolved AD skin, or skin from normal control subjects. Chronic lesions are rich in eosinophils and monocyte/macrophages and contain a greater number of IL-5, granulocyte-macrophage colony-stimulating factor (GM-CSF), and IL-12 (p40) mRNA-positive cells.

OBJECTIVES

In this study, we investigated the mRNA expression of the IL-4 receptor (IL-4Ralpha), IL-5Ralpha, GM-CSFRalpha, and IL-12Rbeta2 in biopsy specimens from acute and chronic AD lesions, uninvolved AD skin, normal skin, and psoriatic skin lesions.

METHODS

Cytokine receptor mRNA was examined in paraformaldehyde-fixed biopsy specimens with in situ hybridization with specific antisense riboprobes.

RESULTS

Acute and chronic skin lesions exhibited a significant increase in numbers of IL-5Rbeta and GM-CSFRalpha mRNA-positive cells compared with uninvolved AD skin and normal skin (P < .001). Chronic skin lesions had a significantly greater number of IL-5Ralpha and GM-CSFRalpha mRNA-positive cells when compared with acute AD skin (P < .001). In contrast, IL-4Ralpha mRNA expression was increased in acute but not chronic AD lesions compared with uninvolved and normal skin (P < .001). No significant differences were observed in numbers of IL-12Rbeta2 mRNA-positive cells when comparing acute AD, chronic AD, uninvolved AD, and normal skin. In psoriatic skin, the numbers of GM-CSFRalpha and IL-12Rbeta2 mRNA-positive cells were significantly increased compared with acute AD lesions, uninvolved skin, and normal control skin (P < .01).

CONCLUSIONS

These results demonstrate that acute AD is associated with a high expression of IL-4Ralpha, whereas IL-5Ralpha and GM-CSFRalpha mRNA are predominantly increased in chronic AD and to lesser extent in acute lesions. These findings support the biphasic role of IL-4, IL-5, and GM-CSF in the pathophysiology of AD.

Serum IgE level is negatively correlated with the ability of peripheral mononuclear cells to produce interferon gamma (IFNgamma): evidence of reduced expression of IFNgamma mRNA in atopic patients

BACKGROUND

In patients with atopic diseases such as bronchial asthma and atopic dermatitis, an elevated serum IgE level is common. Several studies showed that interleukin-4(IL-4) and interferon-gamma (IFNgamma) are important for regulation of IgE production.

OBJECTIVES

The study was designed to examine the pathogenesis of an elevated serum IgE level at the production levels of TH1-type and TH2-type cytokines.

METHODS

The production of interleukin-2 (IL-2), IL-4, interleukin-5 (IL-5) and IFNgamma by peripheral blood mononuclear cells (PBMCs) stimulated with phytohemagglutinin (PHA) was analysed in 20 individuals with various serum IgE levels. The amount of IFNgamma mRNA in the stimulated PBMCs was analysed using a quantitative polymerase chain reaction method.

RESULTS

Cytokine production was analysed simply as a function of serum IgE level. The serum IgE level was negatively correlated with the amount of IFNgamma secreted by PBMCs (n = 20, R = -0.724, P<0.005) when logarithmically transformed data were analysed, but were not or were only weakly correlated with those of IL-4, IL-2, or IL-5 secreted by these cells (n = 20). For investigation of the cause of reduced IFNgamma production in individuals whose serum IgE level are high, the amount of IFNgamma mRNA was determined. The levels of IFNgamma mRNA expression in the stimulated PBMCs correlated well with the amount of IFNgamma secreted by the PBMCs (n = 8, R = 0.947, P < 0.001).

CONCLUSIONS

Reduced IFNgamma production ability due to reduced IFNgamma mRNA expression in PBMCs is associated with an elevated serum IgE level in atopic patients.

Systemic and local immunological features of atopic dermatitis patients with ocular complications

AIMS

Clinical factors and data from recent cases of atopic dermatitis (AD) (with or without ocular complications) and non-AD cases were examined to evaluate the mechanism of atopic ocular complications.

METHODS

IgE-RAST for eight allergens including rice, egg, and mite and serum total IgE were measured in 216 patients with AD (70 ocular type, 146 non-ocular type) and 69 non-AD individuals. Tear histamine and leukotriene B4 (LTB4) levels were also measured.

RESULTS

The serum levels of IgE were significantly increased in AD patients with ocular complications compared with those without ocular complications. The positive rates of IgE-RAST for rice and wheat were significantly higher in ocular type AD than in non-ocular type AD. In ocular type AD, serum IgE was significantly increased in patients with cataract compared with that in those without cataract. Tear histamine and LTB4 levels in AD patients with ocular complications showed significant elevations compared with those in patients with pure AD and controls.

CONCLUSIONS

These results suggest that ocular type AD belongs to the most severe end of the spectrum of AD, and that some food antigens may contribute to the pathogenesis of severe AD resulting in ocular complications.

Immunoglobulin E production in mice by means of contact sensitization with a simple chemical, hapten

Production of IgE caused by repeated topical application of 2,4-dinitrofluorobenzene (DNFB) to the ears of BALB/c mice was investigated. Ear thickness increased in proportion to the number of applications. Eczematous changes of the skin included marked infiltration of neutrophils, eosinophils, and monocytes and hypertrophy of the epidermis. Ear thickness due to inflammation reached a maximum 24 hours after the second, third, fourth, and fifth applications. The strong expression of interferon-gamma and IL-2 messenger RNA (mRNA) in the skin lesions indicated the participation of Th1 type helper T cells in the delayed-type hypersensitivity reaction. After the fifth application, the mice showed an immediate cutaneous reaction in addition to the delayed-type hypersensitivity reaction. The immediate reaction appeared within 1 hour of application. Hapten-specific IgE also was detected in serum from the mice, and the expression of germline and productive Cepsilon mRNA was detected in cervical lymph nodes, whereas productive Cepsilon mRNA was detected in the spleen. These results indicate that five topical applications of DNFB to the ear produce local eczematous dermatitis and increase serum hapten-specific IgE level in mice. Eczematous dermatitis is mainly caused by Th1 type T cells, and IgE production is mediated by Th2 type T cells in the cervical lymph nodes. In addition, IgE class switching occurs in the cervical nodes and IgE production occurs in both lymph nodes and spleen.

Evaluation of soluble cell adhesion molecules in atopic dermatitis

Recent studies have indicated the importance of cell adhesion molecules (CAMs) between the vascular endothelium and activated leukocytes in various inflammatory skin diseases. Soluble forms of CAMs (sCAMs) have also been detected in sera from such diseases. In order to elucidate the role of the soluble forms in skin inflammation, we determined the serum levels of E-selectin, vascular cell adhesion molecule-1 (VCAM-1), and intercellular adhesion molecule-1 (ICAM-1) in patients with atopic dermatitis (AD). Using an enzyme-linked immunosorbent assay, we quantified sCAMs levels in 21 patients with atopic dermatitis and in 16 healthy controls. In severe AD patients, levels of these three types of sCAMs were markedly elevated. sE-selectin was significantly elevated in severe AD over the levels in mild AD. A positive correlation with individual clinical activity was found for changes in the sE-selectin and sVCAM-1 levels. sE-selectin levels were correlated with the serum IgE levels and the number of eosinophils. The sVCAM-1 level was also significantly correlated with the number of monocytes. Among these three molecules, sE-selectin appeared to be the most sensitive clinical parameter in monitoring the clinical course of AD patients.

Interferon-gamma and interleukin-4 production of ovalbumin-stimulated lymphocytes in egg-sensitive children

BACKGROUND

The causal relation between egg allergy and cytokines derived from lymphocytes is unknown.

OBJECTIVE

Interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) production of ovalbumin-stimulated and interleukin-2 (IL-2)-stimulated peripheral blood mononuclear cells from egg-sensitive patients was investigated and compared with that of stimulated peripheral blood mononuclear cells from nonatopic healthy children.

METHODS

Peripheral blood mononuclear cells from egg-sensitive patients and nonatopic healthy children were cultured with ovalbumin and IL-2 for seven days. The IFN-gamma and IL-4 concentrations in culture supernatants of the peripheral blood mononuclear cells were investigated.

RESULTS

The levels of IFN-gamma production of only IL-2-stimulated or both ovalbumin-stimulated and IL-2-stimulated peripheral blood mononuclear cells from egg-sensitive patients with atopic dermatitis was significantly higher than that of healthy children and that of egg-sensitive patients with immediate allergic symptoms.

CONCLUSIONS

Increased IFN-gamma production by lymphocytes after IL-2 and antigen stimulation has important implications for the mechanism of food-sensitive atopic dermatitis.