Atopic dermatitis

Soluble intercellular adhesion molecule-1 and soluble E-selectin levels in patients with atopic dermatitis

The serum levels of soluble intercellular adhesion molecule-1 (sICAM-1) and soluble E-selectin (sE-selectin) were determined by double determinant immunoassay (DDIA), in 37 patients with atopic dermatitis (AD) and 31 age- and sex-matched healthy control subjects. Both sICAM-1 and sE-selectin levels were significantly higher in patients with AD than in healthy controls (P < 0.01), and were correlated with disease severity. A longitudinal study of patients with AD revealed that the levels of sICAM-1 decreased in those in whom symptoms improved. The sICAM-1 levels were significantly correlated with those of sE-selectin. Our studies suggest that such high levels of serum sICAM-1 and sE-selectin may affect the immune response in patients with AD. The levels of sICAM-1 and sE-selectin may be a useful immunological parameter for monitoring disease activity in AD.

Affinity-purified Dermatophagoides farinae antigen induces CD23 on T and B lymphocytes and monocytes specifically in patients with atopic dermatitis

The purpose of this work is to analyze CD23 expression on subpopulations of peripheral blood mononuclear cells (PBMC) from the patients with atopic dermatitis (AD) after stimulation with affinity-purified Dermatophagoides farinae antigen (Af-DF). PBMC from mite-allergic AD patients stimulated with Af-DF induced striking expression of CD23 after the culture. The frequencies of CD23-positive (CD23+) PBMC in the culture were significantly higher than those without stimulation. Most of the CD23+ cells belonged to B lymphocytes and monocytes subsets. CD23 was induced in less than 1% of CD3+, CD4+ and CD8+ lymphocytes by Af-DF. However, significant differences were observed compared to the spontaneous expression, and dose-dependencies were confirmed. No significant increase in the frequencies of CD23+ PBMC was found in non-mite-allergic AD patients and non-atopic donors after stimulation with Af-DF. The kinetics of CD23 expression by Af-DF showed similar patterns to that by IL-4 stimulation. Our results demonstrate that Af-DF can induce CD23 expression on PBMC in mite-allergic AD patients. Based on the high titer of mite-specific IgE antibody in blood of AD, mite antigen may, at least in part, contribute to high CD23 expression in AD.

Elevation of serum-soluble E-selectin in atopic dermatitis

Atopic dermatitis (AD) is characterized by alterations in cellular and humoral immunity. The objective of this study is to determine whether soluble E-selectin (sE-selectin) plays a role in AD. We examined the serum sE-selectin levels in patients with atopic dermatitis (n = 23), patients with urticaria (n = 9), and normal healthy individuals (n = 15). The severity of the disease in the AD patients was graded using an established clinical scoring system. We found that sE-selectin levels were significantly higher in atopic dermatitis than in urticaria (P < 0.001) or normal controls (P < 0.0001). In addition, there was a significant correlation between serum sE-selectin and the clinical score (R = 0.73, P < 0.0001). Clinical improvement was associated with a decrease in both the clinical score (P < 0.01) and serum sE-selectin (P < 0.01). E-selectin was recognized on the vascular endothelial cells of the erythematous lesions of AD patients. These results indicate that sE-selectin may play a role in AD.

Elevation of serum major basic protein in patients with atopic dermatitis

Serum levels of major basic protein (MBP) were measured in patients with atopic dermatitis (AD). The severity of the disease in the AD patients was examined using our clinical scoring system. AD patients showed significantly elevated serum levels of MBP compared with normal controls. There were significant correlations between serum MBP and clinical score. These data indicate that serum MBP could be a possible marker for the disease activity.

Levels of soluble ICAM-1 in atopic dermatitis. A new marker for monitoring the clinical activity?

Levels of soluble intercellular adhesion molecule-1 (sICAM-1) were measured in sera from patients with an acute exacerbation of their atopic dermatitis (AD) (n = 16) on admission to and discharge from our department of dermatology. At admission, the sICAM-1 levels in sera from patients with AD were slightly higher than those of the blood donors (n = 100) and dropped at discharge significantly (P = 0.014) after improvement of the skin conditions. Therefore, sICAM-1 may be, together with soluble interleukin-2 receptor (sIL-2), eosinophilic cationic protein (ECP), and CD14, another marker for monitoring AD.

Eosinophil cationic protein, myeloperoxidase and tryptase in children with asthma and atopic dermatitis

Serum levels of eosinophil cationic protein (ECP), myeloperoxidase (MPO), tryptase, total IgE and differential blood cell counts were studied in atopic children with: 1) moderate to severe asthma using inhaled steroids and symptom-free for the last 3 weeks (n = 13), 2) mild asthma with sporadic symptoms, using only inhaled beta 2-agonists < 3 times/week (n = 15), 3) acute asthmatic attacks admitted to hospital (n = 12), 4) mild to moderate atopic dermatitis (n = 14). Fifteen children without any history of atopy served as controls. ECP, MPO, tryptase and IgE were measured in serum by radioimmunoassays (RIA). The symptom-free children with inhaled steroids had similar median ECP and MPO values as the controls, 8.0 and 360 micrograms/l, vs. 9.0 and 310 micrograms/l, while both ECP and MPO were significantly (p < 0.001) increased in the symptom-free children without anti-inflammatory treatment, 32 and 887 micrograms/l and in those with acute asthma, 28 and 860 micrograms/l. The children with atopic dermatitis had increased ECP but normal MPO levels, 16.0 and 455 micrograms/l. Tryptase in serum was not measurable in any patient. All groups except the control group had significantly elevated total IgE levels. The results indicate that in atopic children serum ECP is a good marker of ongoing asthma or atopic dermatitis. The normal levels of ECP and MPO in the children with asthma using inhaled steroids seem to reflect successful anti-inflammatory treatment. The increased levels of ECP and MPO in the children with mild asthma and no anti-inflammatory treatment may indirectly reflect airway inflammation.

Soluble intercellular adhesion molecule-1 (sICAM-1) in atopic dermatitis

The serum levels of soluble intercellular adhesion molecule-1 (sICAM-1) were determined by enzyme-linked immunosorbent assay, in 88 patients with atopic dermatitis (AD), 29 patients with eczematous dermatitis (ED) and in 33 healthy controls. The sICAM-1 levels were significantly higher in both AD and ED patients than in normal individuals. The longitudinal study of patients with AD revealed a significant decrease in the levels of sICAM-1 (P < 0.05) with improvements in disease activity. In AD patients, the sICAM-1 level correlated significantly with the total numbers of leukocytes and lymphocytes (P < 0.01 and P < 0.05, respectively), whereas no such correlation was found in patients with ED. Our studies show that the levels of sICAM-1 may be a useful immunologic parameter for monitoring disease activity in some of the individuals with AD.

Assessment of eosinophil and neutrophil participation in atopic dermatitis: comparison with the IgE-mediated late-phase reaction

We hypothesized that repeated IgE-mediated late-phase reactions are critical in the pathogenesis of atopic dermatitis (AD). Prior studies have shown that extracellular deposition of eosinophil granule major basic protein (MBP) occurs in lesional AD skin, despite a paucity of infiltrating eosinophils, and that deposition of both neutrophil and eosinophil granule proteins occurs in the IgE-mediated late-phase reaction. We evaluated the participation of both eosinophil and neutrophil granule proteins in AD. Cutaneous biopsy specimens and serum and urine samples were obtained from 22 patients with AD. Lesional tissue was examined by means of immunofluorescence for neutrophil elastase and lactoferrin and for eosinophil granule MBP, eosinophil-derived neurotoxin (EDN), and eosinophil cationic protein (ECP). Serum levels of elastase, MBP, EDN, and ECP and urine levels of MBP, EDN, and ECP were measured. Marked extracellular deposition of at least one of the eosinophil granule proteins was present in the dermis of 15 of the 22 AD skin specimens, but minimal or no extracellular neutrophil elastase or lactoferrin deposition was observed in any specimens. Serum and urine levels of MBP, EDN, and ECP in the patients were elevated when compared with those of normal controls, whereas serum levels of neutrophil elastase were not elevated. Serum MPB levels correlated with extent of body surface involvement. These results suggest that eosinophil degranulation occurs in AD but that neutrophil degranulation does not. Although eosinophil degranulation is prominent in both the late-phase reaction and in AD, the lack of neutrophil degranulation in AD demonstrates differences in the inflammatory reactions.

Leukotriene B4 and C4 generation by blood leukocytes after ex vivo stimulation by Ca-ionophore and opsonized zymosan in children with atopic dermatitis

The ex vivo release of leukotrienes B4 (LTB4) and C4 (LTC4) from the leukocytes of children with atopic dermatitis (AD) was evaluated after stimulation with Ca-ionophore and opsonized zymosan and compared with that of control children of similar ages. The blood eosinophil counts and total serum IgE levels in AD children were significantly higher than those in control children. The production of LTC4, but not LTB4, was significantly higher in AD children than in control children. There was a significant correlation between the relative blood eosinophil count and LTC4 generation after stimulation with both Ca-ionophore and opsonized zymosan in all subjects. Calculations of the amount of LTC4 produced per eosinophilic cell showed that there was no significant difference between cells from AD children and control children in terms of their ability to produce LTC4. These findings suggest that the enhanced LTC4 generation is due to increased numbers of eosinophils rather than to enhanced releasability of these cells.

Identification of monocyte chemotactic factors in supernatants of ovalbumin-stimulated lymphocytes from patients with atopic dermatitis who are sensitive to hen's egg

Monocyte chemotactic activities in supernatants of ovalbumin (OA)-stimulated peripheral blood mononuclear cell (PBMC) cultures were studied in patients with atopic dermatitis (AD) who were sensitive to hen's egg. The monocyte chemotactic activities in hen's egg-sensitive AD patients were significantly higher than those of non-atopic healthy controls and patients with immediate allergic symptoms. However, the monocyte chemotactic activities were not detected in bovine serum albumin-stimulated PBMC culture supernatants in patients with AD who were sensitive to hen's egg, but not to cow's milk. Furthermore, there was significant correlation between the monocyte chemotactic activities and proliferative responses of PBMCs to OA in hen's egg-sensitive AD patients, whereas there was no significant correlation between the monocyte chemotactic activities and radioallergosorbent test values. These results suggest that PBMCs stimulated with food antigens produce monocyte chemotactic factors which relate to the pathogenesis of AD in food-sensitive AD patients and that the pathogenesis of AD may be related to cell-mediated immune responses.

Inhibition of interferon-gamma and interleukin-2 production from lymphocytes stimulated with food antigens by an anti-allergic drug, Tranilast, in patients with food-sensitive atopic dermatitis

N(3',4'-dimethoxycinnamoyl) anthranilic acid (Tranilast) inhibits antibody-mediated hypersensitivity reactions, and is an effective drug for patients with bronchial asthma or allergic rhinitis. Interferon-gamma (IFN-gamma) production of ovalbumin (OA)-stimulated peripheral blood mononuclear cells (PBMCs) from hen's egg-sensitive patients with atopic dermatitis (AD) was significantly higher than those of healthy controls. Tranilast inhibited this IFN-gamma production. Moreover, interleukin-2 (IL-2) production of OA-stimulated PBMCs from hen's egg-sensitive patients with AD was also inhibited by Tranilast. Our results suggest that Tranilast can be used to the patients with food sensitive AD.

Lesional expression of interferon-gamma in atopic eczema

Atopic eczema is thought to be caused by skin-infiltrating CD4 T cells of the Th1-like and/or Th2-like subtype. We assessed expression of the Th1-like cytokine, interferon-gamma, and the Th2-like cytokine, interleukin-4, in lesional atopic skin. Compared with that in normal skin, interferon-gamma and interleukin-4 mRNA expression were increased in eczematous skin lesions in 13 and 4 of 15 patients, respectively. After successful therapy of atopic dermatitis, the increased interferon-gamma mRNA expression but not the increased interleukin-4 mRNA expression was significantly down-regulated. These data indicate that in-situ expression of interferon-gamma is linked to the clinical course of atopic dermatitis.

Suppressive effects of elimination diets on T cell responses to ovalbumin in hen's egg-sensitive atopic dermatitis patients

We investigated the effect of elimination diets on T cell responses to ovalbumin (OA) in hen's egg-sensitive atopic dermatitis (AD) patients. The proliferative responses of both peripheral blood mononuclear cells (PBMCs) and T cells with monocytes to OA decreased after elimination diets, but those to Candida albicans or phytohemagglutinin (PHA) did not decrease after elimination diets. The proliferative responses of CD4+ T cells with monocytes to OA decreased after elimination diets. In these patients, clinical symptoms of AD improved. These results indicate that T cells, especially CD4+ T cells, respond to food antigens in food-specific lymphocyte responses, and that elimination diets may be able to initiate reduction of the responsiveness of food-sensitive T cells, especially CD4+ T cells. Moreover, the surface marker phenotypes of the T cells responding to OA were analysed. Our results showed that CD4+CD45RA+ T cells tended to increase. The increase in circulating CD4+CD45RA+ T cells might function as systemic suppression against immune responses in the skin.

Recombinant interferon gamma therapy for atopic dermatitis

BACKGROUND

Atopic dermatitis is characterized by immunologic abnormalities including evidence for reduced interferon gamma production. Therapeutic options for treatment of atopic dermatitis are limited and unsatisfactory. Previous open trials have suggested efficacy for recombinant interferon-gamma (rIFN-gamma) in treatment of severe atopic dermatitis. We describe the results of treatment with rIFN-gamma, assessing clinical, immunologic, and laboratory safety parameters in 83 patients with moderate to severe atopic dermatitis.

OBJECTIVE

Our purpose was to determine in a randomized, placebo-controlled, double-blind multicenter study the effects of recombinant human interferon gamma therapy in patients with atopic dermatitis.

METHODS

Patients received 50 micrograms/m2 rIFN-gamma (n = 40) or placebo (n = 43) by daily subcutaneous injection for 12 weeks. Seventy-eight patients completed the treatment course; two patients receiving rIFN-gamma (one because of constitutional side effects) and three receiving placebo discontinued treatment before completion. Physician and patient overall response evaluations, clinical severity scores, body surface area involvement, and laboratory parameters were monitored throughout the trial.

RESULTS

Patients in both treatment groups were similar except that the rIFN-gamma group was older and had a longer disease duration. Forty-five percent of rIFN-gamma-treated patients and 21% of placebo-treated patients achieved greater than 50% improvement in physicians' overall response evaluations (p = 0.016). As estimated by patients, responses also showed significant improvement in the rIFN-gamma group compared with the placebo group (53% vs 21%, p = 0.002). Significant reductions in erythema (p = 0.035) and in excoriations or erosions (p = 0.045) occurred in rIFN-gamma-treated patients. Other atopic symptoms such as conjunctivitis (p < 0.002) were also reduced in the rIFN-gamma group. Occasional headaches, myalgias, or chills occurred in 30% to 60% of rIFN-gamma-treated patients but were effectively prevented by pretreatment acetaminophen and by dosing at bedtime. Grade II granulocytopenia occurred in five rIFN-gamma patients but normalized with continued treatment. Reduction to alternate-day dosing was necessary for six patients in the rIFN-gamma group and two in the placebo group. Seven had mild elevations of hepatic transaminase levels that did not affect therapy. The mean eosinophil count was significantly reduced (p = 0.003), whereas a nonsignificant increase in serum IgE levels occurred in the active treatment group.

CONCLUSION

This study demonstrated that rIFN-gamma given by daily subcutaneous injection over a 12-week period was safe, well accepted, and effective in reducing inflammation, clinical symptoms, and eosinophilia in severe atopic dermatitis.

Molecular evolution of the human immunoglobulin E response: high incidence of shared mutations and clonal relatedness among epsilon VH5 transcripts from three unrelated patients with atopic dermatitis

We have analyzed the nucleotide sequences of 19 epsilon VH5 transcripts derived from in vivo isotype switched peripheral blood B cells of three patients with atopic dermatitis. Comparison with the patients' own germline VH5 gene segments revealed that the epsilon transcripts were derived from both functional members of the human VH5 gene family and harbored numerous somatic mutations (range 5-36 per VH5 gene). In two patients, we detected clonally related but diverged transcripts, permitting the construction of a genealogical tree in one patient. We observed a high proportion of shared silent (S) and replacement (R) mutations among epsilon VH5 sequences derived from all three individuals, even among transcripts descending from the two different germline VH5 gene segments. A remarkably high number of these mutations is shared with previously reported VH5 genes encoding antibodies with defined specificities. The shared S mutations, and likely a fraction of the R mutations, appear to mark preferential sites ("hot spots") of somatic hypermutations in human VH5 genes. The distribution of R and S mutations over complementarity determining region and framework regions in the majority of VH regions deviated from that characteristic of antigen-driven immune response. We hypothesize that the V regions of immunoglobulin E-bearing B cells have accumulated "selectively neutral" mutations over extended periods of clonal expansion, resulting in unusual R/S ratios. We propose that the molecular characteristics of the epsilon VH regions in atopic dermatitis may be representative of antigens that recurrently or chronically stimulate the immune system.

Improvement of food-sensitive atopic dermatitis accompanied by reduced lymphocyte responses to food antigen following natural measles virus infection

Five patients with atopic dermatitis (AD) who were sensitive to hen's egg were observed before and after natural measles virus infection. Within 4 weeks of natural measles virus infection, the eczematous lesions clearly improved in four of the five patients in whom neither offending foods were eliminated, nor anti-allergic drugs, systemic steroids and steroid ointment administered. This was accompanied by reduced proliferative responses of peripheral blood mononuclear cells (PBMCs) to ovalbumin (OA). Another patient showed a transient improvement of AD symptoms, from severe to mild, and thereafter returned to severe accompanied by increased proliferative responses of PBMCs to OA. Radioallergosorbent test (RAST) scores for hen's egg in all five patients did not change in each level in each patient, except the transiently decreased RAST scores for hen's egg in one patient, after the infection. Thus, in patients with AD who are sensitive to food, the improvement of AD symptoms that appeared within 4 weeks of natural measles virus infection was related to reduced proliferative responses of PBMCs to the food antigen following the infection.

Soluble CD14 but not interleukin-6 is a new marker for clinical activity in atopic dermatitis

Levels of soluble IL-2 receptors, IL-6, soluble CD23, soluble CD14 and ECP (eosinophilic cationic protein) were measured as markers of T-cell, B-cell, monocyte and eosinophilic leucocyte activation in 26 patients with atopic dermatitis (AD) on admission to (A) and at discharge from (D) the Department of Dermatology in Zurich. The serum levels of sIL-2R, IL-6, sCD23, sCD14 and ECP were significantly elevated in AD patients in comparison with the normal values of healthy donors. A significant decrease in sIL-2R (p = 0.0093) and in sCD14 (p = 0.0134) levels was demonstrated between A and D, correlating with the improvement in the skin intensity score (SIS). In addition, a significant correlation of the sCD14 levels and the SIS at A was demonstrated (p = 0.0415). These results also incriminate monocytes in the pathogenesis of AD, indicating that, besides sIL-2R and ECP, SCD14 could also be a possible marker for the disease activity.

Recent advances in the pathogenesis of atopic dermatitis

Atopic dermatitis (AD) is an inflammatory skin disorder affecting 5%-10% of children. Although basic mechanisms remain largely speculative, recent studies on the pathogenesis have elucidated new insights, pointing to the importance of food and inhalant allergens. The pathogenesis of AD can be more easily explained by the model of late skin reaction occurring after mast cell activation. The present report highlights some of the more recent developments in the mechanisms of AD which can be important in understanding and treating this troublesome disease.

Proliferative responses of CD4+ T-cell population to ovalbumin in patients with atopic dermatitis who are sensitive to hen eggs

Proliferative responses of peripheral blood mononuclear cells and T cells with monocytes to ovalbumin were significantly higher than those of B cells with monocytes to ovalbumin in patients with atopic dermatitis (AD) who were sensitive to hen eggs. The CD4+ T-cell/CD8+ T-cell ratios (the values obtained by dividing the maximum stimulation index of CD4+ T cells with monocytes to ovalbumin by the maximum stimulation index of CD8+ T cells with monocytes to ovalbumin) were significantly higher in AD patients sensitive to hen eggs than in non-atopic healthy controls. The proliferative responses of CD4+ T cells with monocytes to ovalbumin were more intensive than those of CD8+ T cells with monocytes in patients with AD sensitive to hen eggs compared with non-atopic healthy controls. These results suggest that the cells responding to ovalbumin are predominantly CD4+ T cells. However, there was no relationship between the stimulation index of proliferative responses of peripheral blood mononuclear cells to ovalbumin and RAST scores for hen eggs. Thus it is possible that the majority of the CD4+ T cells which respond to ovalbumin are not CD4+ helper T cells for IgE production.

Cord blood lymphocyte responses to food antigens for the prediction of allergic disorders

Proliferative responses of cord blood lymphocytes (CBLs) to food antigens and cord blood IgE concentrations were measured in 37 full term newborn infants for the prediction of allergic disorders. In these 37 infants who were followed up for two years, allergic history of the family was found in four (sensitivity 57.1%) and cord blood IgE concentrations were greater than 0.5 IU/ml in three (sensitivity 42.9%) of seven infants who developed allergic disorders. When CBLs were stimulated twice by ovalbumin or bovine serum albumin, the value of the stimulation index in proliferative responses of CBLs to ovalbumin or bovine serum albumin was greater than 1.5 in six (sensitivity 85.7%) of seven infants who developed allergic disorders. The specificity of the responses of CBLs in the prediction of the development of allergic disorders was 93.3%. The proliferative responses of CBLs to food antigens were useful in the prediction of not only development of allergic disorders but also offending allergens. These observations provide further evidence that sensitisation is occurring in utero. This would appear to be increasingly important in the genesis of early atopic problems. As our follow up is only two years, in utero sensitisation is a prediction for the early development of atopic disease but only longer follow up will show whether this holds good for allergic disorders at any age.

Inhibition of proliferative responses of lymphocytes to food antigens by an anti-allergic drug, N(3',4'-dimethoxycinnamoyl) anthranilic acid (Tranilast) in children with atopic dermatitis

Experimental studies have shown that N(3',4'-dimethoxycinnamoyl) anthranilic acid (Tranilast) inhibits reaginic antibody-mediated hypersensitivity reactions, and it has been demonstrated to be an effective drug for patients with bronchial asthma. On the other hand, from the nature of the cellular infiltrate seen in eczematous lesions, it appears that some form of cell-mediated immunity may be involved in addition to IgE-mediated immunity in the pathogenesis of atopic dermatitis (AD). Moreover, we have previously reported that the proliferative responses of peripheral blood mononuclear cells (PBMCs) to ovalbumin (OA) or bovine serum albumin (BSA) in children with AD who are sensitive to hen's egg or cow's milk were significantly higher than those of healthy children and hen's egg or cow's milk sensitive children with immediate symptoms. In this study, we have showed that the proliferative responses of PBMCs to OA were dose-dependently inhibited by Tranilast on patients with AD. The responding cells to OA were shown, through separation experiments, to be T cells, and the proliferative responses of T cells to OA were also dose-dependently inhibited by Tranilast. Moreover, the inhibition was thought to occur at the initial stage of the proliferative reactions. These results suggest that Tranilast can be clinically applied to patients with AD.

Serum eosinophil cationic protein (ECP) is a sensitive measure for disease activity in atopic dermatitis

Atopic dermatitis (AD) is characterized by alterations in cellular and humoral immunity including elevated serum levels of IgE, IL-2 receptor (IL-2R) and eosinophil cationic protein (ECP). In order to evaluate the relevance of these serum parameters as indicators of disease activity, the concentrations of IgE, IL-2R and ECP were measured in serum samples of patients with an acute exacerbation of AD (n = 19) on admission to hospital and every 6 days up to discharge, and compared with those from normal non-atopic controls (n = 15). The severity of the disease in the AD patients was examined using an established clinical scoring system. On admission, AD patients showed significantly elevated serum levels of IgE, IL-2R and ECP compared with normal controls (P less than or equal to 0.0001). Clinical improvement was associated with a decrease of both the clinical score (P less than or equal to 0.001) and serum ECP levels (P less than or equal to 0.005). No significant changes in serum IgE and serum IL-2R were observed. In addition, there was a significant correlation between serum ECP and the clinical score (R = 0.67, P less than or equal to 0.001). These data indicate that serum ECP may be a helpful tool for monitoring disease activity in AD.

Interleukin-2 production of lymphocytes in food sensitive atopic dermatitis

The proliferative responses of peripheral blood mononuclear cells (PBMC) to food antigens in 22 patients with food sensitive atopic dermatitis were significantly higher than the responses of healthy children and food sensitive children with immediate symptoms. Moreover, the activity of interleukin-2 (IL-2) in supernatants of food antigen stimulated PBMC cultures from patients with atopic dermatitis was significantly higher than that in healthy children and food sensitive children with immediate symptoms. The activity of IL-2 in culture supernatants of separated cell populations stimulated with food antigens from patients with atopic dermatitis and healthy children was investigated. The activity of IL-2 in supernatants of food antigen stimulated T cell cultures could be detected in patients with atopic dermatitis but not in healthy children. These results suggest that the increased IL-2 production after food antigen stimulation is due to increased T cell activity in food sensitive atopic dermatitis.

Altered spontaneous and histamine-induced in vitro suppressor-cell function in dogs with atopic dermatitis

Spontaneous, histamine-induced and Concanavalin A (Con A)-induced suppression of Con A mitogenesis of autologous responder cells was studied in normal dogs and in dogs with atopic dermatitis. Histamine-induced suppression was significantly decreased in the atopic dogs, as was the Con A-induced suppression, at supraoptimal concentration of Con A, to a lesser extent. Total numbers of histamine type 1 or type 2 receptors were not different for cells from atopic or normal dogs. The spontaneous suppression was significantly greater for the atopic dogs and this was not accounted for by the effect of non-specific dermatitis, increased macrophage-induced suppression or increased induction by mitogenic factors in the culture medium. Some possible mechanisms for these results are discussed, and the similarities to suppressor cell function in humans with atopic disease are noted.

Fc epsilon receptor II/CD23+ lymphocytes in atopic dermatitis. III. Aberrant control in the in vitro expression of Fc epsilon RII/CD23 on peripheral blood T cells in atopic dermatitis

In vitro Fc epsilon RII expression was examined in patients with atopic dermatitis, those with non-atopic eczematous dermatitis and normal individuals following stimulation of peripheral blood cells with recombinant IL-4 (rIL-4), phytohaemagglutinin (PHA), or PHA plus rIL-2. At various days cells were stained with MoAbs to human lymphocyte Fc epsilon RII and to lymphoid cell-surface antigens and analysed by flow cytometry. rIL-4, but not rIL-2, specifically induced Fc epsilon RII on T cells as well as B cells in atopic dermatitis, eczematous dermatitis and normal individual groups. Both atopics and non-atopics generated comparable proportions of Fc epsilon RII+ T cells (T epsilon cells), whereas the frequency of B cells bearing Fc epsilon RII(B epsilon cells) was significantly higher in patients with extensive atopic dermatitis than in those with mild atopic dermatitis and other subjects. Comparable levels of T epsilon cells were detected in both atopic and non-atopic donors following stimulation of peripheral blood cells with PHA or pre-activation of the cells with PHA plus subsequent incubation with rIL-2. Whereas both CD8+ and CD4+ subsets were present in T epsilon cell populations induced specifically by rIL-4, PHA and PHA plus rIL-2, patients with atopic dermatitis had a greater tendency for Fc epsilon RII expression on CD8+ T cells compared with patients with eczematous dermatitis and normal individuals. Recombinant interferon-gamma (rIFN-gamma), but not rIFN-alpha or prostaglandin E2 (PGE2), suppressed the generation of T epsilon cells by rIL-4 in atopics and non-atopics to the same degree. These results suggest the aberrant control of Fc epsilon RII expression on T cells, especially those bearing CD8, in atopic dermatitis.

High frequency of IL-4-producing CD4+ allergen-specific T lymphocytes in atopic dermatitis lesional skin

In atopic dermatitis (AD) hypersensitivity reactions to allergens are commonly observed and are assumed to make a major contribution in the pathomechanism of the disease. It may be expected that allergen-reactive Th cells play a central role in these reactions. In the present study the occurrence and function of allergen-specific T lymphocytes in dermal inflammatory lesions were studied. To this aim panels of randomly cloned CD4+ T cells from lesional skin biopsies of two housedust mite Dermatophagoides pteronyssinus (Dp)-allergic AD patients were screened for reactivity with Dp allergens. The results were compared with similar tests for Dp reactivity of T-lymphocyte clones (TLC) from the peripheral blood of these patients. In the panels of TLC generated from lesional skin (S-TLC), a considerable number of TLC appeared to be Dp-specific, 47% (n = 17) and 10% (n = 29), respectively. In the panels from the peripheral blood, the percentages of Dp-specific TLC were only 0% (n = 22) and 3% (n = 34), suggesting accumulation or expansion of these T cells in lesional skin. The function of these TLC was studied by assaying the secretion of IL-4 and IFN-gamma, which have been shown to be produced in aberrant ratios by Dp-specific TLC from the peripheral blood of AD patients (Wierenga et al: J Immunol 144:4651, 1990). All Dp-specific S-TLC produced IL-4 in combination with no or low levels of IFN-gamma, whereas many of the non-Dp-specific S-TLC and blood-derived TLC (B-TLC) were observed to produce high levels of IFN-gamma without significant amounts of IL-4. A functional consequence of these cytokine profiles was demonstrated by the finding that TLC producing substantial amounts of IL-4 enhanced expression of the low-affinity Fc receptor for IgE (CD23) on antigen-presenting cells to a greater extent than did IFN-gamma-producing TLC.

Eosinophil cationic protein in sera of patients with atopic dermatitis

Patients with atopic dermatitis frequently show elevated blood eosinophil counts, and eosinophil-derived major basic protein has been demonstrated in the eczematous skin from patients with atopic dermatitis. To evaluate further the role of eosinophils in the pathogenesis of atopic dermatitis, the concentration of eosinophil cationic protein was measured in serum samples of 42 patients with moderate to severe disease. The results were compared with those obtained in 32 patients with psoriasis with (n = 9) or without (n = 23) a history of inhalant allergy, 12 patients with a history of pseudoallergic reactions to acetylsalicylic acid, 14 patients with a history of inhalant allergy, and 31 nonatopic healthy control subjects. Eosinophil cationic protein levels were significantly increased in the serum of patients with atopic dermatitis (p less than or equal to 0.005) and patients with a history of pseudoallergic reactions to acetylsalicylic acid (p less than or equal to 0.01). There was no significant difference between eosinophil cationic protein levels in patients with psoriasis or a history of inhalant allergy and in control subjects. Moreover, eosinophil cationic protein levels did not differ significantly in psoriasis patients with or without inhalant allergy. These studies support the concept of an active participation of eosinophils in atopic dermatitis and point to a possible role for eosinophils in pseudoallergy.

Skin levels of vasoactive intestinal polypeptide in atopic dermatitis

Atopic dermatitis (AD) can be exacerbated by various factors, including emotional stress, scratching and sweating. The aim of the present study was to evaluate the hypothesis that the inflammatory reaction in AD is also neurogenic. For this purpose, the levels of vasoactive intestinal polypeptide were measured radioimmunologically in whole-tissue homogenates of lesional skin of 13 patients with atopic dermatitis. Radioimmunoassay was performed using an antiserum, AH78, recognizing the carboxy-terminal fragment vasoactive intestinal polypeptide (22-28). Vasoactive intestinal polypeptide immunoreactivity was detected in relatively low amounts in control skin (0.428 +/- 0.08 pmol/g tissue), whereas a marked increase in the peptide was observed in lesional skin of patients with atopic dermatitis (5.62 +/- 1.25 pmol/g tissue). These results seem to suggest that vasoactive intestinal polypeptide could have a pathogenetic relevance in skin lesions of atopic dermatitis.

Fc epsilon receptor II/CD23 positive lymphocytes in atopic dermatitis: II. Infiltration of Fc epsilon R II(+) T cells in the skin lesion

Cells expressing Fc receptors for IgE (Fc epsilon R II) were identified in skin from patients with atopic dermatitis (AD), eczematous dermatitis (ED), and in skin from normal nonatopic subjects, with the use of monoclonal antibodies to human lymphocyte Fc epsilon R II, H107, and to lymphoid cell-surface antigens by double immunofluorescence staining. Two to four percent of infiltrating mononuclear cells expressed Fc epsilon R II, and more than half of these cells were T epsilon cells in both acute and chronic AD lesions. Fc epsilon R II(+) T cells (T epsilon cells) bearing CD8 infiltrated preferentially acute lesions, whereas chronic lesions contained either CD8(+) or CD4(+) T epsilon cells, or both. Fc epsilon R II(+) cells rarely were present in ED lesions. There was no significant correlation between % Fc epsilon R II(+) peripheral blood mononuclear cells and the proportion of lesional Fc epsilon R II(+) cells, extent of skin lesions, or serum IgE levels, implying the selective accumulation of Fc epsilon R II(+) cells in the inflammatory infiltrate of AD. These observations suggest that the increased generation of Fc epsilon R II(+) cells in skin lesions, including CD8 (+) T epsilon cells, is involved in the pathogenesis of AD.

The mast cell in health and disease

The presence of mast cells, often in an activated state or increased numbers, has been noted in various cutaneous disorders. Recent studies suggest that mast cells are of primary importance in these conditions and their presence does not merely represent a secondary event. This review focuses on atopic dermatitis, contact hypersensitivity reactions, bullous pemphigoid, fibrosing conditions, neurofibromatosis, wound healing, polycythemia vera, and psoriasis, in which there is significant evidence to indicate a pathophysiologic role for mast cells.

Temporal association between Der pI exposure, immediate hypersensitivity and clinical severity of eczema

Uncontrolled studies of avoidance of house dust mite (Dermatophagoides pteronyssinus) by atopic subjects have reported clinical improvement in the severity of eczema. The aim of the present study was to examine the temporal relationship between environmental exposure to the major mite allergen (Der pI) and clinical disease severity in children with chronic atopic eczema. Twelve children were identified as being house dust mite-sensitive on the basis of skin prick test and RAST to Der pI. They were examined on two occasions with a median interval of 63 days. Clinical severity of eczema improved in nine children and deteriorated in two children during this period. Der pI concentration in dust from mattresses changed significantly in only three subjects and there was no correlation between changes in clinical severity and changes in environmental Der pI exposure. Change in RAST against Der pI did correlate positively with change in Der pI exposure (rho = 0.56, P less than 0.05) but these changes were not associated significantly with changes in eczema severity or skin test response to Der pI. It is concluded that the observed changes in clinical severity were unlikely to be due to immediate hypersensitivity responses to natural variations in Der pI concentrations in the personal environments of these subjects.

Neuropeptides in skin from patients with atopic dermatitis: an immunohistochemical study

The distribution and localization of several neuropeptides were investigated in the lichenified lesions of 11 patients with atopic dermatitis using indirect immunofluorescence. Substance P-positive nerve fibres were observed in most of the cases of atopic dermatitis, but not in normal controls. Somatostatin immunoreactive nerves were not found in the skin of atopic dermatitis, whereas a normal pattern of immunoreactivity could be detected in most of the healthy subjects. Neuropeptide Y-positive dendritic epidermal cells were observed in lesional skin from patients with atopic dermatitis, but not in controls. Calcitonin gene-related peptide and vasoactive intestinal polypeptide immunoreactivity in patients with atopic dermatitis did not differ from that in healthy subjects. With galanin antiserum a diffuse intracellular staining was observed in the epidermis of both atopic patients and controls, while no positive staining was found with either neurotensin or neurokinin A antibodies in either group. These findings suggest a possible involvement of some neuropeptides in the pathomechanisms of atopic dermatitis.

Immunomodulating cytokines in atopic dermatitis and psoriasis: production of tumour necrosis factor and lymphotoxin by mononuclear cells in vitro

The immunomodulating cytokines, tumour necrosis factor/cachectin (TNF) and lymphotoxin (LT) are thought to play an essential role as mediators of inflammatory reactions. To evaluate the role of TNF and LT in atopic dermatitis (AD) and psoriasis, we investigated their production by mononuclear cells (MNC) in vitro. The 24-h supernatants of lipopolysaccharide (LPS)- and phytohaemagglutinin (PHA)-stimulated and unstimulated MNC from 26 patients with AD and 20 with psoriasis and from 17 non-atopic healthy controls were tested for the concentrations of TNF and LT using an ELISA technique. In patients with AD, TNF levels were significantly decreased in the supernatant of PHA-stimulated (P less than or equal to 0.005) and LPS-stimulated (P less than or equal to 0.02) MNC in comparison to controls. There was no significant difference in TNF production between psoriatic patients and the control group. Release of LT in the supernatant of PHA-stimulated MNC by patients and controls did not differ significantly. There was no significant spontaneous production of TNF and LT by MNC of patients and controls. These studies indicate that different immunomodulating mechanisms are responsible for triggering the inflammatory response in AD and psoriasis.

Nickel sensitivity and the course of atopic dermatitis in adulthood

The course of dermatitis was followed in nickel-sensitive and nickel-negative atopic and non-atopic patients. Manifest dermatitis was seen in 70% of the nickel-allergic and in 64% of the nickel-negative female atopic dermatitis (AD) patients. Those atopic subjects who had minor symptoms in their teens suffered more from dermatitis if they had developed nickel allergy (p less than 0.025). Hands and the head region were the most common sites for current dermatitis in both groups.

IgE antibodies to Pityrosporum orbiculare in children with atopic diseases

IgE antibodies to Pityrosporum orbiculare and 16 other species of fungi were measured with the radioallergosorbent test (RAST) in sera of 131 children. The children were 7-18 years old, suffered from atopic diseases and showed a varied allergic profile on a skin prick test (SPT). IgE antibodies to P. orbiculare were found in the sera of 26 of the 131 children. A higher proportion of the P. orbiculare RAST positive children than of the negative ones had current eczema (p less than 0.0001). In a stepwise logistic regression analysis of SPT and RAST data, the occurrence of serum IgE antibodies to P. orbiculare had the highest explanatory value for current eczema. Ten of 15 children with current atopic eczema and total serum IgE of greater than 500 kU/l had serum IgE antibodies to P. orbiculare. Twenty-four of the 26 P. orbiculare RAST positive children harboured serum IgE antibodies to other fungi. The strong relationship between atopic eczema and the occurrence of IgE antibodies to P. orbiculare indicates that these antibodies may be pathogenetically important in at least some patients with atopic eczema and this gives another dimension to this common skin disease.

Phosphodiesterase and immune dysfunction in atopic dermatitis

Atopic dermatitis and the other atopic conditions occur as a result of direct or indirect influences from cells of hematopoietic origin. Cellular immune abnormalities have been described, but appear to be secondary to cutaneous inflammation in atopic dermatitis. Pharmacophysiologic abnormalities are numerous and may relate to defective cyclic nucleotide metabolism in circulating and infiltrating leukocytes. A consistent leukocyte abnormality is elevated cyclic AMP-phosphodiesterase. This enzyme abnormality results in reduced intracellular cyclic AMP, creating a net permissive effect upon cell function. Phosphodiesterase inhibitors have been demonstrated to reduce abnormal histamine release and IgE production by cultured leukocytes. Studies of phosphodiesterase and associated defects in atopic leukocytes may lead to delineation of basic pathogenetic mechanisms as well as providing the potential for therapeutic targeting.

Food and food additives in severe atopic dermatitis

In this study the role of food additives, tyramine and acetylsalicylic acid, was investigated by double-blind placebo-controlled challenges (DBPCC) in 25 children with severe atopic dermatitis (AD). All children challenged with foods (n = 24), except one, showed one or more positive reactions to the DBPCC with foods. Positive reactions presented as different combinations of flares of skin symptoms, intestinal symptoms and respiratory symptoms. Seventeen children (70.8%) showed a positive challenge to egg, 12 to wheat (50%), eight to milk (33.3%) and eight to soya (33.3%). Six children underwent DBPCC with food additives, tyramine and acetylsalicylic acid. All were found to demonstrate positive skin and/or intestinal reactions to at least one of the food additives. Two children reacted to tartrazine, three to sodium benzoate, two to sodium glutamate, two to sodium metabisulfite, four to acetylsalicylic acid and one to tyramine. It is concluded that some foods, food additives, tyramine and acetylsalicylic acid, can cause positive DBPCC in children with severe AD.

Langerhans cells in delayed skin reactions to inhalant allergens in atopic dermatitis--an electron microscopic study

Langerhans cells at the site of patch tests to inhaled allergens in patients with atopic dermatitis were investigated. Within 24 h the Langerhans cells showed increased cellular activity and became apposed to mononuclear cells. This supports the view that Langerhans cells are involved in antigen presentation in atopic dermatitis.

Dermal mast cell releasability and end organ responsiveness in atopic and nonatopic dogs

The Basenji greyhound (BG) has been proposed as a model of atopic disease because of its chronic relapsing atopic dermatitis as well as airway hyperresponsiveness. We attempted to characterize this model further by comparing its skin wheal-and-flare responses to morphine sulfate and histamine with those of control, nonatopic mongrel dogs. We found that BG dogs had significantly smaller skin responses than did the control dogs to all but two concentrations of histamine used. In contrast, BG dogs demonstrated greater skin response to morphine at the three lowest concentrations used but had a significantly smaller skin response at the highest dose of morphine. Skin punch biopsy specimens revealed decreases in histamine content after morphine exposure but no difference in histamine content of the unexposed skin or of morphine-exposed skin for the two groups of dogs. When percent histamine release was compared, however, BG dogs were found to release a significantly greater proportion of histamine in response to morphine than control dogs. Although there was no significant difference in total mast cell counts for the two groups, the BG dogs had significantly fewer formalin-insensitive mast cells in unexposed skin than control dogs. We conclude that skin responses in BG dogs are characterized by decreased end organ responsiveness and greater releasability of mast cells in response to nonimmunologic stimulation.

The natural history of IgE sensitisation and atopic disease in early childhood

We have prospectively followed 57 children of atopic parents up to 5 years of age, documenting clinical atopic disease and allergen skin test reactions. The cumulative prevalences of the clinical features of atopic disease over the 5 years were: atopic dermatitis (58%), wheeze (49%), recurrent wheeze (33%), rhinitis (68%) and immediate food reactions (18%). Atopic dermatitis and immediate food reactions predominated in infancy (birth to 20 months) while wheezing was more prominent in later childhood (20 months to 5 years). Rhinitis was common in both infancy and childhood. IgE sensitisation to ingested allergens was prominent in early infancy and was usually transient. Inhaled allergen sensitisation occurred later in infancy and was generally permanent with wheal sizes tending to increase with age. There was a significant association between IgE sensitisation to ingested but not inhaled allergens and all atopic manifestations in infancy, with the exception of rhinitis. In contrast IgE sensitisation to inhaled allergens was associated with rhinitis and wheeze in later childhood. We found two clinical groups. One group, with only ingested allergen sensitisation had a high incidence of atopic dermatitis but low incidence of respiratory symptoms at 5 years of age. The other group, who developed evidence of IgE sensitisation to inhaled allergens, had a high incidence of rhinitis and wheeze but low incidence of atopic dermatitis at 5 years of age.

Molecular properties of cyclic nucleotide phosphodiesterase isozymes

Mammalian cells contain multiple molecular forms of cyclic nucleotide phosphodiesterase that differ in substrate specificity and kinetic and regulatory properties. Calcium/calmodulin and cyclic GMP are important regulators of the hydrolysis of cyclic AMP by either stimulating or inhibiting the activity of distinct forms of phosphodiesterase. Several isozymes of cyclic nucleotide phosphodiesterase have been purified to apparent homogeneity. Although some sequence homology is observed the isozymes appear genetically distinct by immunological criteria. Cyclic AMP- and calmodulin-dependent protein kinases can phosphorylate these enzymes and alter their kinetic and regulatory properties. Both tissue specificity and pharmacological selectivity of isozymes have been demonstrated for several drugs. In certain cases, e.g. cardiac muscle, the selective inhibition of a high affinity cAMP phosphodiesterase activity in a specific subcellular fraction correlates with pharmacologic responses. The results from molecular and pharmacologic studies of cyclic nucleotide phosphodiesterases have indeed expanded the role this system of isoenzymes exerts in the regulation of cellular function.

Elevated levels of interleukin 2 receptor in sera of patients with atopic dermatitis and psoriasis

Elevated levels of serum interleukin 2 receptor (IL2R) represent an early measure of T cell activation. The concentration of IL2R was measured in the sera of patients with atopic dermatitis (n = 58) or psoriasis, without psoriatic arthritis, (n = 26), who had moderate to severe disease activity, and in non-atopic healthy controls (n = 37) by an ELISA technique. Serum IL2R levels were found to be significantly elevated in both disease groups compared with the controls. The increase in serum IL2R may be due to T cell activation in the dermis.

Food hypersensitivity and atopic dermatitis

Initially, this article focuses on the pathogenesis of IgE-dependent immediate and late-phase responses in pediatric patients with atopic dermatitis. The article also discusses the role of food hypersensitivity as a major trigger factor exacerbating atopic dermatitis in children. Finally, consideration is given to the prevention of atopic disease through exclusive breast feeding.

IgG-, IgA-, and IgE-induced release of leukotriene C4 by monocytes isolated from patients with atopic dermatitis

Purified peripheral blood monocytes isolated from patients with atopic dermatitis (AD) and from nonallergic normal donors were compared for their abilities to release leukotriene C4 (LTC4), leukotriene B4 (LTB4) and beta-glucuronidase in response to challenge with aggregated immunoglobulins or anti-immunoglobulins. The relationship between mediator release and the number of monocytes that formed rosettes with immunoglobulin-coated indicator cells was examined. Patients with AD had twice as many IgA- and three times as many IgE-rosetting monocytes as normal donors (48 +/- 12% versus 27 +/- 10% and 40 +/- 15% versus 14 +/- 3%, respectively), and yet the amounts of IgA- and IgE-induced LTC4 released were similar for both groups. This apparent discrepancy did not result from a decreased capacity for arachidonate metabolism via the C5-lipoxygenase pathway, since stimulation of monocytes from patients and normal donors with the calcium ionophore A23187 induced similar amounts of LTC4 and LTB4 release (LTC4, 3.0 +/- 1.7 versus 3.0 +/- 1.0 ng/10(6) cells; LTB4, 5.3 +/- 0.7 versus 5.2 +/- 0.5 ng/10(6) cells, respectively). In addition, aggregated IgG-induced LTC4 release by monocytes of both groups was similar, concomitant with an equivalent number of IgG-rosetting cells. Determination of cytophilically bound IgG and IgE by flow cytometry demonstrated that monocytes from atopic patients had more IgG bound than monocytes from normal donors. Similar amounts of IgE were detected on most monocytes from both groups, despite the higher serum IgE levels of patients. However, approximately 3% to 8% of monocytes from atopic but not normal donors stained brightly for IgE, suggesting that relatively large amounts of cytophilic IgE were bound to a small percentage of the patients' monocytes. Challenge of monocytes with anti-IgE or anti-IgG induced release of similar amounts of LTC4 for both groups, despite the presence of more cytophilic IgG on monocytes from atopic donors. These data indicate that monocytes from patients with AD release LTC4 and LTB4 in response to challenge with aggregated IgE or anti-IgE, as well as aggregated IgG, IgA, and anti-IgG. However, under our in vitro conditions, stimulation of patients' monocytes with aggregated IgA or IgE was not associated with increased mediator release, despite higher percentages of IgA- and IgE-rosetting cells compared to normal donors.

Iontophoretic study of skin vessel reactivity in atopic dermatitis and its correlation to serum IgE levels

Skin vessel reactivity was studied by means of an iontophoretic technique in 19 adult patients with atopic dermatitis. Fifteen patients were available for reinvestigation some 6 months later in winter. Compared with a control group, we found a significantly increased sensitivity in summer of dermal skin vessels toward the alpha 1-agonist phenylephrine. Patients with elevated serum IgE levels seemed to be more sensitive to phenylephrine. However, the difference was not significant. Isoproterenol, the beta-adrenoceptor agonist, induced blanching (as opposed to erythema) in 7 of 19 (37%) atopic dermatitis patients in summer and in 9 of 15 (60%) in winter compared with 1 of 36 in the control groups. This blanching was antagonized by the alpha-blocker phentolamine. From the results we concluded that there may be an increased alpha-adrenoceptor reactivity and/or a decreased beta-adrenoceptor reactivity in atopic dermatitis patients, which might be a primary defect.

Surface-bound immunoglobulin E on antigen-presenting cells in cutaneous tissue of atopic dermatitis

Both type I and type IV hypersensitivity reactions have been implicated in the pathogenesis of atopic dermatitis. Using monoclonal antibodies we have identified IgE on the surface of cutaneous dendritic cells in both lesional and nonlesional skin. Double immunofluorescence labeling demonstrates these cells to be antigen-presenting cells. Immunoglobulin E (IgE) was not identified on such cells either in atopic individuals with no history of dermatitis or in patients with a range of other dermatoses. Further studies are consistent with IgE being bound to the cell surface via an Fc-IgE receptor. We conclude that this finding is specific for atopic dermatitis and thus may provide a link between the two types of hypersensitivity reactions frequently observed.