Altered glucocorticoid receptor binding in atopic dermatitis

Dexamethasone and FK506 inhibit expression of distinct subsets of chemokines in human mast cells

Mast cells produce a large amount of several chemokines after cross-linking of FcepsilonRI and participate in the pathogenesis of allergic diseases. The objective of this study was to comprehensively investigate FcepsilonRI-mediated chemokine induction in human mast cells and the effect of a corticosteroid (dexamethasone) and a calcineurin inhibitor (FK506). Human peripheral blood-derived mast cells were stimulated with anti-IgE Ab in the presence of dexamethasone or FK506. Gene expression profiles were evaluated using GeneChip and confirmed by real-time PCR, and chemokine concentrations were measured by cytometric bead arrays and ELISA. Expression of eight chemokines was significantly induced in mast cells by anti-IgE stimulation. Induction of CCL2, CCL7, CXCL3, and CXCL8 by anti-IgE was significantly inhibited by dexamethasone but was enhanced by FK506. In contrast, induction of CCL1, CCL3, CCL4, and CCL18 was significantly inhibited by FK506 but, with the exception of CCL1, was enhanced by dexamethasone. Combination of dexamethasone and FK506 suppressed production of all chemokines by anti-IgE stimulation. Studies using protease inhibitors indicate that mast cell proteases may degrade several of the chemokines. These results suggest that corticosteroids and calcineurin inhibitors inhibit expression of distinct subsets of chemokines, and a combination of these drugs almost completely suppresses the induction of all chemokine genes in human mast cells in response to FcepsilonRI-dependent stimulation. This implies that a combination of a corticosteroid and a calcineurin inhibitor may be more effective than each single agent for the treatment of allergic diseases in which mast cell-derived chemokines play a major role.

Atopic dermatitis: beyond the itch that rashes

The prevalence of atopic dermatitis is increasing, and more than 50% of children with atopic dermatitis go on to develop asthma and allergies. A better understanding of the underlying immune abnormalities of this complex chronic relapsing skin disease is needed. Although the optimal treatment approach remains to be defined, several recent studies suggest a rationale for using topical calcineurin inhibitors as early intervention and adding topical corticosteroids as rescue therapy if needed.

Topical treatment of atopic dermatitis

Topical therapy of atopic dermatitis should incorporate an understanding of the underlying immune abnormalities of this complex chronic skin disease. Avoidance of irritants and proven allergens, skin hydration, and use of emollients and anti-inflammatory therapy help maintain a normal skin barrier. Topical calcineurin inhibitors have been added to the topical treatment armamentarium. Although the optimal treatment approach remains to be defined, several studies suggest the use of topical calcineurin inhibitors as early intervention therapy and topical corticosteroids as rescue therapy.

Presence of atopy in first-degree relatives as a predictor of a female proband's depression: results from the Northern Finland 1966 Birth Cohort

BACKGROUND

Recent investigations suggest a common genetic rather than environmental cause to explain the association between IgE-mediated atopic allergies and depression.

OBJECTIVE

Taking into account psychosocial confounding factors, we investigated separately and at the epidemiologic level the effects of maternal, paternal, and sibling atopy on the cumulative incidence of a child's depression.

METHODS

We used an unselected, genetically homogenous, general population birth cohort of 12,058 live-born children in Finland. The 31-year prospective follow-up included questionnaire information on atopic disorders of the cohort members' parents and siblings. The probands' own atopic conditions were evaluated by means of skin prick tests, and information on lifetime depression diagnoses was gleaned from postal questionnaires and national hospital discharge registers. Potential confounders were mother's parity, father's social class, maternal smoking during pregnancy, proband's regular daily smoking, and proband's dwelling place. Total variable information was available from 4068 cohort members.

RESULTS

Among female probands, the presence of atopy in parents was the strongest predictor for lifetime depression (P <.001), and sibling atopy and parental atopy were the strongest predictors for hospital-treated depression (P =.018 and P =.036, respectively). After controlling for confounders, it was noticed that maternal atopy increased a female proband's risk of lifetime depression up to 1.9-fold (odds ratio, 1.9; 95% CI, 1.1-3.0). The corresponding risk increased over 4-fold if parental-maternal atopy was combined with proband's own atopy.

CONCLUSIONS

Our findings suggest that maternal inheritance could be a significant causative factor in the association between atopy and depression of female probands.

Association between skin test diagnosed atopy and professionally diagnosed depression: a Northern Finland 1966 Birth Cohort study

BACKGROUND

Several studies have suggested an association between IgE-mediated atopic allergies and depression, although thus far no epidemiologic evidence involving a large, unselected, general-population sample and valid methods in diagnosing atopy support this putative association.

METHODS

We used the Northern Finland 1966 Birth Cohort, which was followed prospectively to age 31. Of the total cohort, 5428 individuals underwent skin tests for three of the most common allergens (i.e., cat, birch, and timothy grass) and for dust mites (Dermatophagoides pteronyssinus). Data on doctor-diagnosed lifetime depression were obtained from questionnaires.

RESULTS

After adjusting for social class, mothers' parity, place of residence, and psychiatric morbidity, the logistic regression analysis showed that the risk of developing depression when compared with nonatopic subjects increased up to 1.8-fold in atopic women (adjusted odds ratio 1.8, 95% confidence interval [CI] 1.2-2.6) and, when compared with skin-test-negative female subjects without allergic symptoms, reached 2.7-fold increases (95% CI 1.6-4.6) in those suffering from clinically manifest atopic disorders. Corresponding associations were not found among male subjects.

CONCLUSIONS

Our results indicate that women suffering from atopic diseases may possess an elevated risk for developing depression during early adulthood. Possible background theories (i.e., genetic abnormalities in serotonin metabolism, hypothalamic-pituitary-adrenal axis dysfunction, and histamine theory) are discussed.

Stress response, tachykinin, and cutaneous inflammation

In the last decade, several new aspects of glucocorticoid (GC)-actions on immune cells have been recognized. This recognition has been largely obtained through clinical observations of stress-induced exacerbations of certain dermatologic diseases. To clarify whether GC modulates cutaneous inflammatory reactions besides its known anti-inflammatory effect, first we examined the effect of long-term application of topical GC on several kinds of inflammatory responses induced in the murine model and demonstrated that these regimens significantly augmented the classical contact sensitivity reaction, the croton oil-induced irritant reaction, and the IgE-mediated biphasic cutaneous reaction. In addition, large dose topical steroid and its withdrawal enhanced scratching behavior in hapten-challenged mice. This augmented scratching behavior correlated with the induction of preprotachykinin mRNA expression in the challenged skin. In an in vitro experiment, a low-dose, stress-induced level of glucocorticoid significantly upregulated hapten-induced proinflammatory cytokine (IL1alpha) production by murine keratinocyte cell line Pam 212 and induced substance P peptide production from cultured human keratinocytes. Our results suggest that unsuitable use of GC in addition to stress-induced GC may modulate immune function in the skin through aberrant production of tachykinin, such as substance P or other epidermal cell derived cytokines.

Association and linkage of atopic dermatitis with chromosome 13q12-14 and 5q31-33 markers

Atopic dermatitis is a chronic inflammatory skin disease that affects 10-20% of the population. Linkage of atopy, asthma, allergic rhinitis, and total serum IgE levels to several different chromosomal regions have been described extensively, but little is known about the genetic control of atopic dermatitis. We tested for the association and linkage between atopic dermatitis and five chromosomal regions: 5q31-33, 6p21.3, 12q15-24.1, 13q12-31, and 14q11.2/14q32.1-32.3. Marker analysis was performed in two Caucasian populations: (i) 192 unrelated German children with atopic dermatitis and 59 non-atopic children from a German birth cohort study (MAS'90), parental DNA was tested in 77 of 192 children with atopic dermatitis; (ii) 40 Swedish families with at least one family member with atopic dermatitis selected from the International Study of Asthma and Allergy in Children. Evidence for linkage and allelic association for atopic dermatitis was observed for markers on chromosome 13q12-14 and 5q31-33.

Atopic dermatitis: new insights and opportunities for therapeutic intervention

Atopic dermatitis (AD) is a chronic inflammatory skin disease that frequently predates the development of allergic rhinitis or asthma. It is an important skin condition with significant costs and morbidity to patients and their families; the disease affects more than 10% of children. Recent studies have demonstrated the complex interrelationship of genetic, environmental, skin barrier, pharmacologic, psychologic, and immunologic factors that contribute to the development and severity of AD. The current review will examine the cellular and molecular mechanisms that contribute to AD as well as the immunologic triggers involved in its pathogenesis. These insights provide new opportunities for therapeutic intervention in this common skin condition.

Hypothalamic-pituitary-adrenal function and glucocorticoid sensitivity in atopic dermatitis

OBJECTIVES

Topical glucocorticoids (GCs) fail to produce a clinical response in some children with atopic dermatitis (AD), suggesting that GC resistance may be present. To determine whether such resistance is generalized or specific to diseased skin, hypothalamic-pituitary-adrenal (HPA) axis function has been assessed in children with moderate to severe AD, who showed a variable response to treatment with topical GC.

STUDY DESIGN

Thirty-five patients (.7-18.7 years old; median: 9.3 years) with AD requiring topical GCs from infancy underwent a low-dose adrenocorticotrophin hormone (ACTH; Synacthen) test (LDST) (500 ng/1.73 m(2) ACTH). Groups 1 (7 patients), 2 (17 patients), and 3 (4 patients) used mild, moderate, or potent/very potent topical preparations, respectively. Group 4 (7 boys with severe, treatment-resistant disease) had received GC in at least 1 form (inhaled +/- intranasal +/- oral) in addition to varying potencies of topical GC. Fourteen healthy subjects (3.8-17.3 years old) served as control subjects. Group 4 patients had a daytime plasma cortisol profile and 08.00 hours measurement of plasma ACTH and its precursors.

RESULTS

The response to ACTH for groups 1 and 2 did not differ from that of control subjects. Group 3 had lower peak, increment, and area under curve cortisol responses than those in controls, whereas group 4 had lower baseline, peak, and area under curve cortisol responses. Eight patients failed the LDST (peak cortisol <500 nmol/L and increment <200 nmol/L): controls = 0/14, group 1 = 0/7, group 2 = 1/17, group 3 = 4/4, and group 4 = 3/7. Treatment score (based on GC potency, area treated, and duration) was the only factor to influence peak cortisol response on LDST (r(2) = 24%). In group 4, only 1 of 7 patients had a cortisol profile within the normal range but he failed the LDST. In the 5 subjects with an 08.00 hours cortisol <300 nmol/L, the matched ACTH level was inappropriately low.

CONCLUSIONS

HPA suppression was rarely found in children or adolescents with moderate to severe AD who used mild or moderately potent topical GCs over many years. However, HPA suppression was common in those receiving potent topical GC preparations or a combination of GC routes of administration. In those with severe AD, evidence of HPA suppression but lack of clinical response to GC treatment excluded significant generalized GC resistance. This would suggest that localized resistance to GCs within the diseased skin may be part of the aetiopathogenesis of severe AD.

Glucocorticoids inhibit proliferation and interleukin-4 and interleukin-5 secretion by aeroallergen-specific T-helper type 2 cell lines

BACKGROUND

Glucocorticoids play an important role in the treatment of allergic disease. The atopic process, itself, may reduce the response of peripheral blood mononuclear cells (PBMC) to these drugs.

OBJECTIVE

In this study we compared the effect of hydrocortisone (HC), beclomethasone (BDP), and mometasone (MF) on interleukin (IL)-4 and IL-5 secretion by aeroallergen-specific T-helper type 2 cells (Th2) and proliferation of PBMC from atopic donors.

METHODS

Cells were incubated with drug before stimulating with phytohemagglutinin and assessing proliferation (PBMC) and cytokine secretion (Th2).

RESULTS

The glucocorticoids concentration dependently inhibited proliferation and cytokine secretion, but had less effect on proliferation of cells from severe atopics than on cells from those whose symptoms required little treatment. The rank order of potency was MF (average IC50 0.01 nM) > BDP (4.0 nM) > HC (250 nM).

CONCLUSIONS

These experiments demonstrate glucocorticoid inhibition of IL-4 and IL-5 secretion by human Th2-like cells and proliferation of PBMC from severely and mildly allergic donors.

Molecular basis of allergic diseases

This review examines our current understanding of the mechanisms underlying allergic diseases. The IgE molecule plays a central role in the pathogenesis of immediate hypersensitivity reactions by virtue of its capacity to bind specifically to high-affinity IgE receptors on mast cells and mediate the release of various mast cell-derived mediators and proinflammatory cytokines on exposure to allergen. Clinically significant allergic responses are followed by a late-phase response dominated by eosinophils and T lymphocytes. The majority of T cells in allergic responses are memory T cells secreting helper type 2 (TH2)-like cytokines, i.e., interleukin (IL)-4, IL-5, IL-13, but not interferon-gamma. These cytokines regulate IgE synthesis and promote eosinophil development, thus contributing to allergic inflammatory responses. Failure to control immune activation early in the course of allergic disease blunts responses to glucocorticoid therapy and contributes to disease progression. The identification of key cells and molecules involved in the initiation and maintenance of allergic inflammation is likely to become an important target in the treatment of this common group of illnesses.

Immunologic basis of chronic allergic diseases: clinical messages from the laboratory bench

During the past decade there have been significant advances in our understanding of the mechanisms underlying allergic responses. Immediate hypersensitivity reactions are mediated primarily by mast cells in an IgE-dependent manner. After the local release of various mediators, proinflammatory cytokines, and chemokines, there is a cell-mediated response that is dominated by eosinophils and T lymphocytes. The majority of T cells in early allergic reactions are memory T cells secreting helper type 2 (TH2)-like cytokines, i.e. IL-4, IL-5, and IL-13, but not interferon-gamma. These cytokines regulate IgE synthesis and promote eosinophil differentiation and cell survival, thus contributing to allergic inflammatory responses. Failure to control immune activation early in the course of allergic inflammation may blunt the response to glucocorticoid therapy and contribute to long-term morbidity of disease. The identification of key cells and cytokines involved in the initiation and maintenance of allergic inflammation is likely to become an important therapeutic target in the future management of this important group of diseases.

Clinical applications of cytokines: new directions in the therapy of atopic diseases

OBJECTIVES

This review will enable the readers to understand the pathogenesis of allergic inflammation, and the role of various cells and cytokines in allergic diseases. Pathogenic cytokines may become key therapeutic targets in the future treatment of allergic diseases.

DATA SOURCES

MEDLINE literature search limited to the English language was performed using the relation between specific cytokines and allergic inflammation as well as therapy of allergic diseases. Relevant articles referenced in retrieved sources and current texts on ctyokines and allergic responses were also utilized.

RESULTS

The mechanism underlying allergic inflammation involves complex interactions between various cells and cytokines. The immediate reaction is caused mainly by mast cells and followed by a cell mediated response that involves eosinophils, mononuclear cells, neutrophils, T lymphocytes and macrophages. The majority of T cells in early allergic reactions are T helper type 2 (TH2)-like producing IL-4, IL-5, IL-13 but not IFN-gamma. These cytokines regulate IgE synthesis, promote eosinophil differentiation and survival, and induce vascular endothelial adhesion molecules, thus contributing to allergic inflammation.

CONCLUSIONS

Although studies of cytokine modulation have utilized animal models of allergic diseases, the increasing availability of recombinant cytokines and cytokine antagonists is likely to lead to more wide scale applications in allergic diseases.

Evaluation of non-steroidal ointment therapy for adult type atopic dermatitis: inquiry analysis on clinical effect

Clinical analysis was performed on non-steroidal ointment therapy for 70 patients with refractory adult-type atopic dermatitis by the clinical data and patient's own evaluation of the therapy obtained through enquiries after discharge from the hospital. Forty cases (57%) were between 20 and 30 years old and the male and female ratio was 39/31. The clinical evaluations were subdivided into five groups; conditions worsened (n = 9), no-change (n = 9), slightly improved (n = 14), much improved (n = 29) and cured (n = 9). Although statistically not significant, the age of onset of atopic dermatitis and the start of use of steroid ointment was much higher while the duration of the atopic dermatitis was much shorter in the remission patients. The duration of steroid ointment therapy for the facial skin was significantly shorter in the remission group when compared to groups with worsened symptoms and no-change in symptoms. Family history and complications of atopic diseases, laboratory data including IgE titer, eosinophils and RAST score were not statistically significant in any group except for a higher prevalence of IgE antibodies against inhalant and food allergens in the group with worsened symptoms. Most patients still used steroid ointment on the trunk lesions while they ceased using from the topical steroid on the facial lesions after discharge. Most frequent precipitating factors pointed out by the patients were emotional stress, irritation by sweat or UV light and longstanding use of steroid ointment. Complications of cataracta and retinopathy were found in 12 cases. These results suggest that remission of adult-type refractory atopic dermatitis can be achieved by the combination of careful daily skin care, use of non-steroidal topical ointment and minimizing the precipitating factors.