Atopic dermatitis complicated by recurrent eczema herpeticum is characterized by multiple, concurrent epidermal inflammatory endotypes

BACKGROUND

A subgroup of atopic dermatitis (AD) patients suffer from recurrent, disseminated herpes simplex virus (HSV) skin infections, termed eczema herpeticum (EH), which can be life-threatening and contribute to AD morbidity. The pathobiology underlying ADEH is unknown.

OBJECTIVE

To determine transcriptional mechanisms of skin and immune system pathobiology that underlie ADEH disease.

METHODS

We performed whole transcriptome RNA-sequencing of non-lesional skin samples (epidermis, dermis) of AD patients with (ADEH + , n=15) and without (ADEH - , n=13) recurrent EH history, and healthy controls (HC, n=15). We also performed RNA-sequencing on plasmacytoid dendritic cells (pDCs) collected from these participants and infected in vitro with HSV-1. Differential expression, gene set enrichment, and endotyping analyses were performed.

RESULTS

ADEH + disease was characterized by dysregulation in skin gene expression, which was limited in dermis (differentially expressed genes [DEGs]=14) and widespread in epidermis (DEGs=129). ADEH + -upregulated epidermal DEGs were enriched in type 2 cytokine (T2) ( IL4R, CCL22, CRLF2, IL7R ), interferon ( CXCL10, ICAM1, IFI44 , and IRF7) , and IL-36γ ( IL36G ) inflammatory pathway genes. At a person-level, all ADEH + participants exhibited T2 and interferon endotypes and 87% were IL36G-high. In contrast, these endotypes were more variably expressed among ADEH - participants. ADEH + patient skin also exhibited dysregulation in epidermal differentiation complex (EDC) genes within the LCE, S100 , and SPRR families, which are involved in skin barrier function, inflammation, and antimicrobial activities. pDC transcriptional responses to HSV-1 infection were not altered by ADEH status.

CONCLUSIONS

ADEH + pathobiology is characterized by a unique, multi-faceted epidermal inflammation that accompanies dysregulation in the expression of EDC genes.

Key Messages

AD patients with a history of recurrent EH exhibit molecular skin pathobiology that is similar in form, but more severe in degree, than in AD patients without this complication. Non-lesional skin of ADEH + patients concurrently exhibits excessive type 2 cytokine, interferon, and IL-36γ-driven epidermal inflammation. Expression of these inflammatory skin endotypes among ADEH + patients is associated with dysregulation in expression of epidermal differentiation complex genes involved in barrier function, inflammation, and antimicrobial activity.

Capsule Summary

AD patients with a history of recurrent disseminated HSV-1 skin infections form a unique molecular skin endotype group that concurrently exhibits type 2 cytokine, interferon, and IL-36γ-driven skin inflammation, accompanied by dysregulation in expression of epidermal differentiation complex genes involved in barrier function, inflammation, and antimicrobial activity.

Consensus guidelines for interventional cardiology services delivery during covid-19 pandemic in Australia and new Zealand

The global coronavirus disease (COVID-19) pandemic poses an unprecedented stress on healthcare systems internationally. These Health system-wide demands call for efficient utilisation of resources at this time in a fair, consistent, ethical and efficient manner would improve our ability to treat patients. Excellent co-operation between hospital units (especially intensive care unit [ICU], emergency department [ED] and cardiology) is critical in ensuring optimal patient outcomes. The purpose of this document is to provide practical guidelines for the effective use of interventional cardiology services in Australia and New Zealand. The document will be updated regularly as new evidence and knowledge is gained with time. Goals Considerations.

Developing drugs for treatment of atopic dermatitis in children (≥3 months to <18 years of age): Draft guidance for industry

Atopic dermatitis is the most common chronic skin disease, and it primarily affects children. Although atopic dermatitis (AD) has the highest effect on burden of skin disease, no high-level studies have defined optimal therapy for severe disease. Corticosteroids have been used to treat AD since the 1950s and remain the only systemic medication with Food and Drug Administration approval for this indication in children, despite published guidelines of care that recommend against this option. Several clinical trials with level 1 evidence have supported the use of topical treatments for mild to moderate atopic dermatitis in adults and children, but these trials have had little consistency in protocol design. Consensus recommendations will help standardize clinical development and trial design for children. The Food and Drug Administration issues guidance documents for industry as a source for "the Agency's current thinking on a particular subject." Although they are nonbinding, industry considers these documents to be the standard for clinical development and trial design. Our consensus group is the first to specifically address clinical trial design in this population. We developed a draft guidance document for industry, Developing Drugs for Treatment of Atopic Dermatitis in Children (≥3 months to <18 years of age). This draft guidance has been submitted to the Food and Drug Administration based on a provision in the Federal Register (Good Guidance Practices).

Transcriptional Profiling of Egg Allergy and Relationship to Disease Phenotype

Background

Egg allergy is one of the most common food allergies of childhood. There is a lack of information on the immunologic basis of egg allergy beyond the role of IgE.

Objective

To use transcriptional profiling as a novel approach to uncover immunologic processes associated with different phenotypes of egg allergy.

Methods

Peripheral blood mononuclear cells (PBMCs) were obtained from egg-allergic children who were defined as reactive (BER) or tolerant (BET) to baked egg, and from food allergic controls (AC) who were egg non-allergic. PBMCs were stimulated with egg white protein. Gene transcription was measured by microarray after 24 h, and cytokine secretion by multiplex assay after 5 days.

Results

The transcriptional response of PBMCs to egg protein differed between BER and BET versus AC subjects. Compared to the AC group, the BER group displayed increased expression of genes associated with allergic inflammation as well as corresponding increased secretion of IL-5, IL-9 and TNF-α. A similar pattern was observed for the BET group. Further similarities in gene expression patterns between BER and BET groups, as well as some important differences, were revealed using a novel Immune Annotation resource developed for this project. This approach identified several novel processes not previously associated with egg allergy, including positive associations with TLR4-stimulated myeloid cells and activated NK cells, and negative associations with an induced Treg signature. Further pathway analysis of differentially expressed genes comparing BER to BET subjects showed significant enrichment of IFN-α and IFN-γ response genes, as well as genes associated with virally-infected DCs.

Conclusions

Transcriptional profiling identified several novel pathways and processes that differed when comparing the response to egg allergen in BET, BER, and AC groups. We conclude that this approach is a useful hypothesis-generating mechanism to identify novel immune processes associated with allergy and tolerance to forms of egg.

Toward an Objective Diagnostic Test for Bacterial Cellulitis

Background

Prior studies repeatedly showed that cultures of skin lesions diagnosed as "cellulitis" are usually negative. However, lack of a gold standard for diagnosis (against which culture might be judged) and failure to assess the human immune response are important limitations of prior work. In this pilot study, we aimed to develop a criterion standard for research on bacterial cellulitis, to evaluate the sensitivity of procalcitonin for bacterial cellulitis, and to use gene expression analysis to find other candidate diagnostic markers.

Methods

We classified lesions via biopsies, 16s rRNA gene detection, culture, and histopathology. We quantified procalcitonin expression in blood. We also used Nanostring technology to quantify transcription of immunomodulators that may distinguish cases from inflamed controls.

Results

Of 28 participants, 15 had a clinical diagnosis of cellulitis, six had a diagnosis of non-infectious dermatitis, and seven were normal volunteers. Of the “cellulitis” patients, three (20%) had pathogens isolated, and were designated confirmed cases. Procalcitonin was undetectable in all three. HLA-DQA1 was expressed 34-fold more in confirmed cases vs. controls (fold change of geometric mean). Heat maps depicting multiplex gene expression analysis revealed a distinct profile of gene expression in confirmed cases relative to comparators.

Conclusions

Most “cellulitis” patients had microbiologically-negative biopsies. Procalcitonin was undetectable, and HLA-DQA1 elevated, in confirmed bacterial cases. Multivariable transcriptomic profiling results supported our algorithm’s ability to identify patients with true bacterial cellulitis. A larger sample may allow discovery of an immunological signature capable of distinguishing bacterial cellulitis from its mimics in clinical practice.

Esophageal microbiome in eosinophilic esophagitis

Objective

The microbiome has been implicated in the pathogenesis of a number of allergic and inflammatory diseases. The mucosa affected by eosinophilic esophagitis (EoE) is composed of a stratified squamous epithelia and contains intraepithelial eosinophils. To date, no studies have identified the esophageal microbiome in patients with EoE or the impact of treatment on these organisms. The aim of this study was to identify the esophageal microbiome in EoE and determine whether treatments change this profile. We hypothesized that clinically relevant alterations in bacterial populations are present in different forms of esophagitis.

Design

In this prospective study, secretions from the esophageal mucosa were collected from children and adults with EoE, Gastroesophageal Reflux Disease (GERD) and normal mucosa using the Esophageal String Test (EST). Bacterial load was determined using quantitative PCR. Bacterial communities, determined by 16S rRNA gene amplification and 454 pyrosequencing, were compared between health and disease.

Results

Samples from a total of 70 children and adult subjects were examined. Bacterial load was increased in both EoE and GERD relative to normal subjects. In subjects with EoE, load was increased regardless of treatment status or degree of mucosal eosinophilia compared with normal. Haemophilus was significantly increased in untreated EoE subjects as compared with normal subjects. Streptococcus was decreased in GERD subjects on proton pump inhibition as compared with normal subjects.

Conclusions

Diseases associated with mucosal eosinophilia are characterized by a different microbiome from that found in the normal mucosa. Microbiota may contribute to esophageal inflammation in EoE and GERD.

IL-2 and IL-4 stimulate MEK1 expression and contribute to T cell resistance against suppression by TGF-beta and IL-10 in asthma

The T cell-driven airway inflammation in chronic asthma is uninhibited and sustained. We examined the resistance of T cells from asthmatic patients against suppression by TGF-β, IL-10 and glucocorticoids and explored its signaling mechanism. CD4(+)CD25(-) T cells from allergic asthmatic subjects demonstrated increased TCR-stimulated proliferation as compared with healthy and chronic obstructive pulmonary disease controls. This proliferation was resistant to inhibition by TGF-β, IL-10, and dexamethasone and to anergy induction. CD4 T cells from asthmatic patients, but not chronic obstructive pulmonary disease, allergic rhinitis, and healthy subjects, showed increased expression of MEK1, heightened phosphorylation of ERK1/2, and increased levels of c-Fos. IL-2 and IL-4 stimulated the expression of MEK1 and c-Fos and induced T cell resistance. The inhibition of MEK1 reversed, whereas induced expression of c-Fos and JunB promoted T cell resistance against TGF-β- and IL-10-mediated suppression. We have uncovered an IL-2- and IL-4-driven MEK1 induction mechanism that results in heightened ERK1/2 activation in asthmatic T cells and make them resistant to certain inhibitory mechanisms.

Induction of glucocorticoid receptor-beta expression in epithelial cells of asthmatic airways by T-helper type 17 cytokines

BACKGROUND

Corticosteroid insensitivity in asthmatics is associated with an increased expression of glucocorticoid receptor-beta (GR-beta) in many cell types. T-helper type 17 (Th17) cytokine (IL-17A and F) expressions increase in mild and in difficult-to-treat asthma. We hypothesize that IL-17A and F cytokines alone or in combination, induce the expression of GR-beta in bronchial epithelial cells.

OBJECTIVES

To confirm the expression of the GR-beta and IL-17 cytokines in the airways of normal subjects and mild asthmatics and to examine the effect of cytokines IL-17A and F on the expression of GR-beta in bronchial epithelial cells obtained from normal subjects and asthmatic patients.

METHODS

The expression of IL-17A and F, GR-alpha and GR-beta was analysed in bronchial biopsies from mild asthmatics and normal subjects by Q-RT-PCR. Immunohistochemistry for IL-17 and GR-beta was performed in bronchial biopsies from normal and asthmatic subjects. The expression of IL-6 in response to IL-17A and F and dexamethasone was determined by Q-RT-PCR using primary airway epithelial cells from normal and asthmatic subjects.

RESULTS

We detected significantly higher levels of IL-17A mRNA expression in the bronchial biopsies from mild asthmatics, compared with normal. GR-alpha expression was significantly lower in the biopsies from asthmatics compared with controls. The expression of IL-17F and GR-beta in biopsies from asthmatics was not significantly different from that of controls. Using primary epithelial cells isolated from normal subjects and asthmatics, we found an increased expression of GR-beta in response to IL-17A and F in the cells from asthmatics (P< or =0.05). This effect was only partially significant in the normal cells. Dexamethasone significantly decreased the IL-17-induced IL-6 expression in cells from normal individuals but not in those from asthmatics (P< or =0.05).

CONCLUSION

Evidence of an increased GR-beta expression in epithelial cells following IL-17 stimulation suggests a possible role for Th17-associated cytokines in the mechanism of steroid hypo-responsiveness in asthmatic subjects.

Advanced applications of 3-dimensional echocardiography

Over the last few decades, advancements in ultrasound, electronic and computing technologies have permitted current second generation 3-dimensional (3D) echocardiography to display on-line 3D rendered images of the heart. Since various studies demonstrated its superiority over 2-dimensional echocardiography, there is growing enthusiasm to embrace this new 3D echocardiographic technology. With its increasing widespread clinical availability, 3D echocardiography is getting closer to routine clinical use. However, as with any new emerging technologies, clinical applications of 3D echocardiography should be based on current evidence. This review will focus on the evidence from clinical studies that form the scientific basis for the advanced applications of 3D echocardiography, from cardiac chamber volume assessments, left ventricular dyssynchrony assessments, quantifications of valvular abnormalities, to the role of 3D echocardiography during cardiac interventions.

How compliant are we with guidelines for coronary angiography in clinical practice?

BACKGROUND

The American College of Cardiology and American Heart Association have published guidelines for coronary angiography. We evaluated the compliance rate with these guidelines in clinical practice, its correlation to results of angiography and aimed to identify problem areas of non-compliance.

METHODS

We prospectively evaluated 802 consecutive referrals for coronary angiography over 5 months in 2002 in a tertiary referral hospital. These referrals were assessed by two independent reviewers blinded to the results of angiography.

RESULTS

Patient age was 62 +/- 11 years (522 men, 433 inpatients, 369 day-only patients). Referrals were outside published guidelines in 34.3 and 36.2% as evaluated by the two reviewers (concordance rate 88.2%, kappa = 0.74, p < 0.001). Intraobserver agreement was 97.5%. The rate of angiography showing either normal arteries or only minor diseases (<50%) was higher for referrals outside guidelines (68.4 vs 22.6%, P < 0.001). Compliance rate was high with indications of non-ST-elevation myocardial infarction (99.2%) and ST-elevation myocardial infarction (95.8%), valvular disease (80%) and arrhythmia (80%). Compliance rate was lower with assessment of dyspnoea or heart failure (74.3%) and before non-cardiac surgery (72.7%) and was particularly low with assessment of chest pain (53.2%). Younger age (odds ratio (OR) 1.04, P < 0.001), female sex (OR 2.67, P < 0.001), day-only procedure (OR 2.27, P < 0.001) and non-invasive cardiologist referrer (OR 1.41, P = 0.046) were independent predictors of non-compliance.

CONCLUSION

Referrals for coronary angiography were outside guidelines in a significant proportion of patients. Rate of negative angiography was higher when the referrals were outside guidelines. Problematic areas of non-compliance could be identified. Measures specifically targeting these areas may be more effective in improving the overall guideline compliance in clinical practice.

End points in clinical trials: are they moving the goalposts?

In selecting and defining composite end points in clinical trials, are we trading off clinical significance for statistical significance?

Functional and prognostic implications of left ventricular contractile reserve in patients with asymptomatic severe mitral regurgitation

OBJECTIVE

To evaluate contractile reserve (CR) determined by exercise echocardiography in predicting clinical outcome and left ventricular (LV) function in asymptomatic severe mitral regurgitation (MR).

DESIGN

Cohort study.

SETTING

Regional cardiac centre.

PATIENTS AND OUTCOME MEASURES

LV volumes and ejection fraction (EF) were measured at rest and after stress in 71 patients with isolated MR. During follow up (mean (SD) 3 (1) years), EF and functional capacity were serially assessed and cardiac events (cardiac death, heart failure, and new atrial fibrillation) were documented.

RESULTS

CR was present in 45 patients (CR+) and absent in 26 patients (CR-). Age, resting LV dimensions, EF, and MR severity were similar in both groups. Mitral surgery was performed in 19 of 45 (42%) CR+ patients and 22 of 26 (85%) CR- patients. In patients undergoing surgery, CR was an independent predictor of follow up EF (p = 0.006) and postoperative LV dysfunction (EF < 50%) persisted in five patients, all in the CR- group. Event-free survival was lower in surgically treated patients without CR (p = 0.03). In medically treated patients, follow up EF was preserved in those with intact CR but progressively deteriorated in patients without CR, in whom functional capacity also deteriorated.

CONCLUSIONS

Evaluation of CR by exercise echocardiography may be useful for risk stratification and may help to optimise the timing of surgery in asymptomatic severe MR.

Use of a quantitative point-of-care test for the detection of serum cardiac troponin T in patients with suspected acute coronary syndromes

We compared a third generation quantitative cardiac troponin T (cTnT) point-of-care testing (POCT) from Roche Diagnostics with the laboratory assay (Roche Elecsys 2010 immunoassay analyser). Heparin-treated blood and serum were collected simultaneously in 133 unselected patients (mean age 62 +/- 14 years, 38% females) presenting to our hospital with possible cardiac chest pain. Results of the POCT were measured against the laboratory-based assay considered as the gold standard. There were 18 POCT positive versus 24 laboratory assay positive (> or = 0.03 ng/mL) patients. POCT was falsely negative in six patients, with values between 0.03 and 0.1 ng/mL. The POCT had a sensitivity of 75%, specificity of 100%, positive predictive value of 100%, negative predictive value of 95% and a total accuracy of 95%; kappa = 0.831 (P < 0.001). There was good correlation between the values of POCT and the laboratory assay: Y = 1.195X + 0.002, r2 = 0.94 (P < 0.0001). Whereas cTnT levels > 0.1 mg/mL were reliably detected with this current generation of POCT, cTnT levels between 0.03 and 0.10 ng/mL were not. Future generations of devices will need to improve sensitivity to reliably risk stratify patients with suspected acute coronary syndromes.

The keratinocyte as a target for staphylococcal bacterial toxins

Skin infections with Staphylococcus aureus are not only an important cause of morbidity and even mortality, but are thought to serve as initiation and/or persistance factors for numerous inflammatory skin diseases, including psoriasis and atopic dermatitis. One mechanism by which S. aureus can modulate the immune system is through the production of proteins such as superantigenic toxins, Protein A, as well through the cytolytic alpha-toxin. This review serves to discuss the biology of these three types of proteins, with emphasis on their ability to stimulate the production of powerful pro-inflammatory lipid- and protein-derived cytokines in keratinocytes. Characterization of interactions between these proteins and the keratinocyte can provide a better understanding of how bacterial infection modulates inflammatory skin diseases, as well as provide the basis for improved therapies involving antibacterial agents.

Clarithromycin potentiates glucocorticoid responsiveness in patients with asthma: results of a pilot study

BACKGROUND

Selected macrolide antibiotics have steroid-sparing effects in patients with steroid-dependent asthma. In addition to inhibiting methylprednisolone clearance, macrolides may also display anti-inflammatory effects.

OBJECTIVE

To determine whether clarithromycin, by virtue of its anti-inflammatory effects, enhances glucocorticoid sensitivity.

DESIGN

Open-label, pilot study in a paired design (pre- and posttreatment).

PARTICIPANTS

Seven patients, mean age 27 (range 15 to 42 years), with mild to moderate asthma under good control.

METHODS

Clarithromycin (500 mg) was administered twice daily for 10 days with blood drawn for lymphocyte stimulation assays at baseline, and again upon completion of therapy. Lymphocytes were stimulated with phytohemagglutinin in the presence and absence of increasing concentrations of clarithromycin and dexamethasone (DEX).

RESULTS

At baseline, clarithromycin alone did not cause a significant degree of suppression of T-lymphocyte activation, yet clarithromycin significantly enhanced the sensitivity of lymphocytes to suppression by DEX as measured by a shift in the DEX dose-response curve by at least 6-fold (P = 0.04). In addition, a 10-day course of clarithromycin resulted in: 1) a significant decrease in the inhibitory concentration which results in a 50% reduction in proliferation for DEX alone, thereby increasing glucocorticoid sensitivity (P = 0.04); 2) heightened inhibitory effect of clarithromycin alone (P = 0.03); and 3) a sustained suppressive effect with the combination of clarithromycin and DEX on the inhibition of lymphocyte stimulation (P = 0.01).

CONCLUSIONS

Clarithromycin acts synergistically with DEX in suppressing lymphocyte activation. In addition, a 10-day course resulted in a significant treatment effect as evidenced by lower inhibitory concentration which results in a 50% reduction in proliferation value for DEX, a heightened response to clarithromycin alone, and a consistent degree of suppression of lymphocyte stimulation when clarithromycin and DEX were used together.

Pathophysiologic mechanisms in atopic dermatitis

Atopic dermatitis is a common, chronic inflammatory skin disease that frequently predates the development of asthma and/or allergic rhinoconjunctivitis. Recent studies have provided new insights into how the complex interrelationship of genetic, environmental, and immunologic factors may contribute to the development of atopic dermatitis. This article examines some of the factors involved in chronic cutaneous inflammation in this disease. Greater understanding of the mechanisms that underlie the pathophysiology of atopic dermatitis may lead to improved treatment strategies for this increasingly common skin disease.

Onset and persistence of childhood asthma: predictors from infancy

OBJECTIVE

In a prospective study of children with a family history of asthma, asthma onset by 3 years of age was found previously to be positively associated with variables from the first year of life, including elevated total immunoglobulin E (IgE), frequent respiratory infections, and parenting difficulties. We followed this cohort of genetically at-risk children to investigate the relationship between factors assessed in infancy and asthma, allergy, and psychological status at school age.

METHODS

A cohort of 150 children who were at risk for developing asthma were identified prenatally on the basis of the mothers' having asthma. For 28 children, the father had asthma as well, putting them at bilateral genetic risk. Families primarily were middle and upper middle class Caucasians. Parents came to the clinic during the third trimester of pregnancy for assessments of medical and psychosocial functioning. A home visit took place when the infant was 3 weeks old, when parenting risk was assessed before the onset of any asthma symptoms. Parenting difficulties included problems with infant caregiving as well as components of maternal functioning, such as postpartum depression and inadequate marital support. Blood was drawn for serum IgE at 6 months of age. Parents and offspring subsequently came to the clinic multiple times, with the last clinic visit during the child's sixth year. Follow-up at age 6 involved a clinic visit for allergy and psychosocial evaluations, consisting of interviews and a behavior questionnaire. Seventy-seven children received the allergy and psychosocial evaluation, 26 received the psychosocial evaluation in the clinic, and 30 families received telephone interviews and mailed in questionnaires. Additional monitoring of families by telephone and mail was maintained over the next 2 years, until the children were 8, to ensure accurate characterization of the course of illness. Comprehensive medical records were obtained and reviewed for all health care contacts. Children were designated as having asthma when there was documentation in medical records of physician-diagnosed asthma, observed wheezing, and/or prescription of asthma medications during the time period when the child was between 6 and 8 years of age. Parental reports of the occurrence of asthma corroborated the medical record data.

RESULTS

Data regarding asthma status were available for 145 children through 8 years of age. Forty (28%) of the children manifested asthma between 6 and 8 years of age. Among variables previously reported to predict asthma onset by age 3, 3 proved to have significant univariate relationships with asthma between ages 6 and 8: elevated IgE levels measured when the children were 6 months of age, global ratings of parenting difficulties measured when infants were 3 weeks old, and higher numbers of respiratory infections in the first year of life. Among these offspring of mothers with asthma, paternal asthma showed a significant association with asthma between ages 6 and 8. Eczema in the first year was not significantly related to later asthma. Multiple logistic regression showed that the model that best predicted asthma at ages 6 to 8 from infancy variables included 2 main effects. The adjusted odds ratio for 6-month IgE was 2.15 (1.51, 3.05) and for parenting difficulties was 2.07 (1.15, 3.71). Although socioeconomic status (SES) was not associated with asthma at ages 6 to 8, families of lower SES were more likely to be rated as having parenting difficulties early in the child's life. The mothers of lower SES breastfed for a shorter period of time and were more likely to smoke during their infant's first year. There were more respiratory infections during the first year of life among infants whose mother was rated as having more parenting difficulties. Mothers who reported smoking breastfed their infants for a shorter length of time. Male gender was significantly associated with higher IgE levels when infants were 6 months of age. Laboratory testing was completed for 77 children at age 6. Total serum IgE levels were significantly higher for the children with asthma between ages 6 and 8. Skin-prick testing showed that the children with asthma had significantly more positive skin test reactions than did the children without asthma. Psychosocial interview data at 6 years of age were available for 103 families, and behavioral questionnaires were available for 133 families. On the basis of 6-year interviews, children with asthma were rated as being at greater psychological risk than were the children without asthma. Mothers' Child Behavior Checklist (CBCL) ratings of their children's behavior indicated higher internalizing scores for the children with asthma as compared with the children without asthma. Like the 6-month IgE, 6-year IgE was higher for boys. IgE levels measured at 6 months of age were significantly correlated with 6-year IgE levels. Parenting difficulties measured at 3 weeks were significantly correlated with 6-year measures of maternal depression, CBCL Internalizing score, and Child Psychological Risk (CPR) score. There also were significant correlations among the psychosocial variables assessed when the children were 6 years of age; maternal depression was significantly associated with child CBCL Internalizing score and CPR score, and the last 2 also were significantly correlated. Multiple logistic regression showed that 2 concurrently measured variables entered the model showing the strongest associations with asthma at ages 6 to 8. The adjusted odds ratio for CPR score was 3.21 (1.29-7.96) and for 6-year IgE was 1.71 (1.04-2.80).

CONCLUSIONS

This study of the natural history of childhood asthma focused on the development of asthma into the school-age years in a genetically at-risk group of children. The relationships between biological and psychosocial variables in the first year and school-age asthma support the formulation of asthma as beginning early in life, with the developing immune system interacting with environmental influences. The data provide support for the possible contribution of psychosocial factors to asthma onset and persistence into childhood.

Fibronectin and fibrinogen contribute to the enhanced binding of Staphylococcus aureus to atopic skin

BACKGROUND

Staphylococcus aureus colonizes the skin lesions of more than 90% of patients with atopic dermatitis (AD). The mechanism for increased S aureus colonization in AD is unknown. However, the initial event in colonization requires adherence of S aureus to the skin.

OBJECTIVE

The purpose of this study was to examine the roles of various bacterial adhesins on S aureus binding to AD skin.

METHODS

In an attempt to delineate the mechanism behind this adherence process, an in vitro bacterial binding assay was developed to quantitate the adherence of various S aureus strains to AD, psoriatic, and normal skin sections. S aureus strains used in this study were obtained either from cultures of AD skin lesions or from genetically manipulated strains of S aureus that lacked specific microbial surface components recognizing adhesive matrix molecules (MSCRAMMs)--namely, fibronectin-binding protein (Fnbp), fibrinogen-binding protein (Clf), collagen-binding protein (Cna), and their parent strains. In addition, S aureus strains from patients with AD were pretreated with fibronectin or fibrinogen to block MSCRAMM receptors and interfere with binding.

RESULTS

Under all experimental conditions, binding of S aureus was localized primarily to the stratum corneum. Immunocytochemical staining of AD skin sections showed a redistribution of fibronectin to the cornified layer, an observation not seen in normal skin. S aureus binding to uninvolved AD skin was significantly greater than the binding to uninvolved psoriatic skin (P <.0001) and normal skin (P <.0005). The Fnbp-negative S aureus showed a significant reduction in binding to the AD skin (P <.0001) but not to the psoriatic and normal skin. In the AD skin, a significant reduction in the binding of S aureus was also observed in the Clf-negative strain (P <.0001) but not in the Cna-negative S aureus. Preincubation of S aureus with either fibronectin or fibrinogen also inhibited bacterial binding to AD skin (P <.0001).

CONCLUSION

These data suggest that fibronectin and fibrinogen--but not collagen--play a major role in the enhanced binding of S aureus to the skin of patients with AD.

Preferential binding of Staphylococcus aureus to skin sites of Th2-mediated inflammation in a murine model

Staphylococcus aureus is found on over 90% of atopic dermatitis skin lesions and is thought to contribute to skin inflammation via the production of potent exotoxins. In contrast, less than 5% of normal subjects harbor S. aureus. This suggests that an atopic immune response itself may play a role in preferential binding of S. aureus to the skin. To examine this issue more directly, we analyzed the S. aureus binding characteristics of skin in mice undergoing different T helper type 1 cell versus T helper type 2 cell inflammatory responses using a novel in vitro bacterial binding assay. BALB/C female mice were first sensitized to ovalbumin with alum or ovalbumin with complete Freund's adjuvant to induce T helper type 2 or T helper type 1 responses, respectively. Mice were then challenged intradermally with either saline (control) or ovalbumin. Forty-eight hours later, skin specimens were obtained from the challenge sites, and the number of S. aureus binding to each skin section was quantitated. Bacterial binding was found to be significantly greater at skin sites of BALB/C mice that had been ovalbumin/alum sensitized compared with ovalbumin/complete Freund's adjuvant sensitized (p < or = 0.01). When compared to the ovalbumin sensitized/challenged skin of wild type BALB/C mice or interferon-gamma gene knockout mice, interleukin-4, but not interferon-gamma, gene knockout mice had significantly less S. aureus binding at their ovalbumin sensitized/challenged skin sites. Mutant S. aureus strains that lacked either fibronectin- or fibrinogen-binding protein expression showed significantly reduced S. aureus binding compared with the parent wild type strain (p < 0.005). Moreover, preincubation of the wild type bacteria with fibronectin or fibrinogen, but not collagen, resulted in significantly less skin binding of S. aureus (p < 0.01). Incubation of skin with interleukin-4, and less so with interferon-gamma, led to more binding of wild type S. aureus but not of an S. aureus mutant deficient in fibronectin binding protein expression. After interleukin-4 incubation, but not interferon-gamma, epidermal immunoreactivity for fibronectin was observed in murine skin explants. These results show that a T helper type 2 inflammatory environment can promote skin binding by S. aureus and that this binding is mediated by fibronectin and fibrinogen.

GRbeta expression in nasal polyp inflammatory cells and its relationship to the anti-inflammatory effects of intranasal fluticasone

BACKGROUND

Nasal polyposis disease is an inflammatory disorder with intense eosinophilic infiltration of respiratory mucosa that is often difficult to control with topical steroids. Recent evidence suggests that overexpression of the glucocorticoid receptor splice variant GRbeta in inflammatory cells might contribute to steroid insensitivity in diseases such as asthma.

OBJECTIVE

The purposes of this investigation were to determine whether nasal polyp (NP) inflammatory cells overexpress GRbeta and to examine whether GRbeta overexpression is associated with insensitivity to the potent topical steroid fluticasone propionate (FP).

METHODS

Biopsies were obtained from 10 subjects with NPs before and 4 weeks after treatment with intranasal FP. Middle turbinates biopsies from 6 healthy, nonallergic subjects served as normal controls. Biopsies were immunostained for inflammatory cell markers as well as GRbeta and probed for various cytokine mRNA. The anti-inflammatory response to FP was examined in relation to pretreatment levels of GRbeta expression.

RESULTS

The total numbers of inflammatory cells were increased in NPs. The percentage of inflammatory cells expressing GRbeta was also increased (40.5% +/- 19.2% vs 16.1% +/- 4.0%, P =.009). GRbeta expression in NPs was almost exclusive to T lymphocytes, eosinophils, and macrophages. An inverse correlation was observed between the baseline inflammatory cell GRbeta expression and the reduction after FP treatment in EG2-positive eosinophils, CD4-positive T lymphocytes, endothelial VCAM-1 expression, and IL-4 mRNA-positive cells. NPs that were "FP-insensitive" in terms of suppression of eosinophil numbers (major basic protein-positive) had a significantly greater percentage of GRbeta-positive inflammatory cells, a higher ratio of GRbeta-positive/GRalpha-positive cells, and increased numbers of GRbeta-positive eosinophils and macrophages in comparison with those that were "FP-sensitive." "FP-insensitive" NPs also demonstrated a higher percentage of IL-5-positive inflammatory cells expressing GRbeta before and after FP treatment.

CONCLUSION

GRbeta expression appears to be a marker of steroid insensitivity in NPs. Expression of GRbeta by NP inflammatory cells, particularly T cells and eosinophils, might render them resistant to suppression by topical steroids and thereby contribute to persistent NP inflammation.