Nasal carriage of Staphylococcus aureus in house dust mite allergic patients and healthy controls

Nasal carriage of Staphylococcus aureus in children with grass pollen‐induced allergic rhinitis and the effect of polyvalent mechanical bacterial lysate immunostimulation on carriage status: A randomized controlled trial

Background

Numerous studies indicate that Staphylococcus aureus (S. aureus) colonizing the nasal cavity plays a role in the pathogenesis of allergic rhinitis (AR). This bacterium is able to produce a variety of toxins with superantigenic properties that can exacerbate allergic inflammation.

Objective

The objective of the study was to evaluate the ability of polyvalent mechanical bacterial lysate (PMBL) to eliminate S. aureus nasal carriage in children with grass pollen‐induced AR.

Methods

This randomized, double‐blind, placebo‐controlled study included 80 children aged 5–17 years with seasonal AR (SAR). At the randomization visit and after 12 weeks of the study, a swab was taken from the region of the middle nasal meatus. Standard microbiology culture and identification techniques were used to analyze the swab contents.

Results

Nasal colonization by S. aureus was confirmed in 29 children (42%), with Moraxella catarrhalis in three participants (4.4%). Physiological flora was detected in 37 children. No statistically significant differences were observed between the two measurement points in both the PMBL and placebo groups with respect to the number of patients whose nasal swab cultures showed a growth of S. aureus (p = 1). Both groups also showed no significant changes in the mean number of S. aureus colonies in nasal swab cultures taken at baseline and after 12 weeks of the study (PMBL group p = .41; placebo group p = .16).

Conclusion

Almost every second child with SAR is S. aureus nasal carrier. Sublingual administration of PMBL in children with grass pollen‐induced AR did not affect S. aureus nasal colonization. Therefore, PMBL should not be used for the eradication of S. aureus from the nasal cavity.

Symbiotic microbiome Staphylococcus aureus from human nasal mucus modulates IL-33-mediated type 2 immune responses in allergic nasal mucosa

Background

The host-microbial commensalism can shape the innate immune responses in respiratory mucosa and nasal microbiome also modulates front-line immune mechanism in the nasal mucosa. Inhaled allergens encounter the host immune system first in the nasal mucosa, and microbial characteristics of nasal mucus directly impact the mechanisms of initial allergic responses in nasal epithelium. However, the roles of the nasal microbiome in allergic nasal mucosa remain uncertain. We sought to determine the distribution of nasal microbiomes in allergic nasal mucosa and elucidate the interplay between nasal microbiome Staphylococcus species and Th2 cytokines in allergic rhinitis (AR) models.

Results

Staphylococcus aureus (AR-SA) and S. epidermidis (AR-SE) were isolated from the nasal mucosa of patients with AR. The influence of nasal microbiome Staphylococcus species on allergic nasal mucosa was also tested with in vitro and in vivo AR models. Pyrosequencing data showed that colonization by S. epidermidis and S. aureus was more dominant in nasal mucus of AR subjects. The mRNA and protein levels of IL-33 and TSLP were significantly higher in AR nasal epithelial (ARNE) cells which were cultured from nasal mucosa of AR subjects, and exposure of ARNE cells to AR-SA reduced IL-33 mRNA and secreted protein levels. Particularly, ovalbumin-driven AR mice inoculated with AR-SA by intranasal delivery exhibited significantly reduced IL-33 in their nasal mucosa. In the context of these results, allergic symptoms and Th2 cytokine levels were significantly downregulated after intranasal inoculation of AR-SA in vivo AR mice.

Conclusion

Colonization by Staphylococcus species was more dominant in allergic nasal mucosa, and nasal commensal S. aureus from subjects with AR mediates anti-allergic effects by modulating IL-33-dependent Th2 inflammation. The results demonstrate the role of host-bacterial commensalism in shaping human allergic inflammation.

Staphylococcus Aureus in chronic airway diseases: An overview

This review investigates about the role of Staphylococcus Aureus (S. aureus) and S. aureus enterotoxins (SEs) in the pathogenesis of several chronic airway diseases. S. aureus is part of normal human flora and may colonize the skin and the upper airways. SEs acting as superantigens can induce an intense T cell activation and through the release of interleukin (IL) - 4, 5, and 13, can promote a polyclonal IgE response and eosinophilic inflammation. S. aureus can damage epithelial cells inducing the release of the so-called "alarmins" responsible of the activation of Type 2 innate lymphoid cells (ILC-2) linked to an IL-5 mediated airway eosinophilic inflammation. SEs sensitization has been recently associated with the eosinophilic endotypes of both nasal polyps and late onset severe asthma. Studies investigating the effect of biological therapies in SEs sensitized patients should be performed in order to better define the role played by S. aureus in the different endotypes of severe asthma and/or chronic rhinosinusitis.

Association of Staphylococcus aureus colonization with food allergy occurs independently of eczema severity

BACKGROUND

Staphylococcus aureus has been implicated in the pathophysiology of eczema, allergic rhinitis, asthma, and food allergy. S aureus is a marker of more severe eczema, which is a risk factor for food sensitization/allergy. Therefore it might be that the association between S aureus and food allergy in eczematous patients is related to eczema severity.

OBJECTIVE

We sought to investigate the association of S aureus colonization with specific IgE (sIgE) production to common food allergens and allergies in early childhood independent of eczema severity. We additionally determined the association of S aureus colonization with eczema severity and persistence.

METHODS

In Learning Early About Peanut Allergy (LEAP) study participants eczema severity was assessed, and skin/nasal swabs were cultured for S aureus. Sensitization was identified by measuring sIgE levels. Peanut allergy was primarily determined by means of oral food challenge, and persistent egg allergy was primarily determined by using skin prick tests.

RESULTS

Skin S aureus colonization was significantly associated with eczema severity across the LEAP study, whereas at 12 and 60 months of age, it was related to subsequent eczema deterioration. Skin S aureus colonization at any time point was associated with increased levels of hen's egg white and peanut sIgE independent of eczema severity. Participants with S aureus were more likely to have persistent egg allergy and peanut allergy at 60 and 72 months of age independent of eczema severity. All but one of the 9 LEAP study consumers with peanut allergy (9/312) were colonized at least once with S aureus.

CONCLUSION

S aureus, independent of eczema severity, is associated with food sensitization and allergy and can impair tolerance to foods. This could be an important consideration in future interventions aimed at inducing and maintaining tolerance to food allergens in eczematous infants.

Staphylococcus aureus Colonization of the Human Nose and Interaction with Other Microbiome Members

Staphylococcus aureus is usually regarded as a bacterial pathogen due to its ability to cause multiple types of invasive infections. Nevertheless, S. aureus colonizes about 30% of the human population asymptomatically in the nares, either transiently or persistently, and can therefore be regarded a human commensal as well, although carriage increases the risk of infection. Whereas many facets of the infection processes have been studied intensively, little is known about the commensal lifestyle of S. aureus. Recent studies highlight the major role of the composition of the highly variable nasal microbiota in promoting or inhibiting S. aureus colonization. Competition for limited nutrients, trace elements, and epithelial attachment sites, different susceptibilities to host defense molecules and the production of antimicrobial molecules by bacterial competitors may determine whether nasal bacteria outcompete each other. This chapter summarizes our knowledge about mechanisms that are used by S. aureus for efficient nasal colonization and strategies used by other nasal bacteria to interfere with its colonization. An improved understanding of naturally evolved mechanisms might enable us to develop new strategies for pathogen eradication.

Role of Superantigens in Allergic Inflammation: Their Relationship to Allergic Rhinitis, Chronic Rhinosinusitis, Asthma, and Atopic Dermatitis

OBJECTIVES

Our intention was to review all material published to date regarding superantigens (SAgs) and allergy from an otorhinolaryngological viewpoint to understand this association more clearly.

METHODS

We identified all materials published mentioning both SAg and allergic rhinitis (AR), chronic sinusitis, asthma, and atopic dermatitis (AD) that are indexed on PubMed, Google, or the ProQuest Central databases.

RESULTS

Staphylococcus aureus is a significant bacterial pathogen in humans and has the ability to produce enterotoxins with superantigenic features. The inflammatory response in allergy seen in both B cell and T cell may be attributed to SAgs. Sufferers of both allergic asthma with rhinitis and AR alone produce serological evidence of immunoglobulin E formation to SAgs produced by S. aureus. Perennial AR sufferers carry S. aureus more frequently and the presence of the organism within the nasal cavity may exacerbate perennial AR. SAg produced by S. aureus potentially worsens the asthmatic inflammatory response within the airway and may lead to the airways becoming hyperresponsive, as well as possibly activating T cells if asthmatic control is poor. Staphylococcal SAgs potentially increase the risk of developing chronic rhinosinusitis with nasal polyposis, additionally being a marker for more severe disease. If SAgs bring about chronic inflammatory responses in the nose and sinuses, then T cells excreting interferon-gamma may be a crucial mediator. In allergic dermatitis, S. aureus could be a key player in exacerbation of the condition. Even in younger pediatric patients with allergic dermatitis, allergic hypersensitivity to SAgs is frequent and may be a factor explaining how severe the condition becomes.

CONCLUSION

Just as SAgs are known to feature in many allergic conditions, they play their part in AR, chronic rhinosinusitis, asthma, and AD. Further research is required before the relationship between SAgs and allergy can be adequately explained.

The commensal lifestyle of Staphylococcus aureus and its interactions with the nasal microbiota

Although human colonization by facultative bacterial pathogens, such as Staphylococcus aureus, represents a major risk factor for invasive infections, the commensal lifestyle of such pathogens has remained a neglected area of research. S. aureus colonizes the nares of approximately 30% of the human population and recent studies suggest that the composition of highly variable nasal microbiota has a major role in promoting or inhibiting S. aureus colonization. Competition for epithelial attachment sites or limited nutrients, different susceptibilities to host defence molecules and the production of antimicrobial molecules may determine whether nasal bacteria outcompete each other. In this Review, we discuss recent insights into mechanisms that are used by S. aureus to prevail in the human nose and the counter-strategies that are used by other nasal bacteria to interfere with its colonization. Understanding such mechanisms will be crucial for the development of new strategies for the eradication of endogenous facultative pathogens.

Staphylococcus aureus enterotoxin sensitization is associated with allergic poly-sensitization and allergic multimorbidity in adolescents

BACKGROUND

Staphylococcus aureus (S. aureus) carriage and sensitization to S. aureus enterotoxins (SEs) have been associated with allergic diseases. From the Tromsø Study Fit Futures 2, we have previously shown an association between S. aureus carriage and severe allergic disease and allergic multimorbidity. However, the role of S. aureus carriage and SE sensitization on allergic multimorbidity and allergic sensitization is unclear.

OBJECTIVE

To study associations of both nasal S. aureus carriage and SE sensitization to allergic disease and allergic sensitization.

METHODS

A cross-sectional study of a school-based cohort in late adolescence (aged 18-19 years: The Tromsø Study Fit Futures 2). Self-reported allergic diseases were assessed using the Mechanisms of the Development of ALLergy questionnaire (MeDALL). Participants were tested for nasal S. aureus carriage, serum total IgE and specific IgE to SEs, and food and inhalant allergens.

RESULTS

A total of 868 participants were studied. Sensitization to at least one food or inhalant allergen was found in 319 of 765 (41.7%), and to at least one SE in 173 of 656 (26.2%) participants. SE sensitization, but not S. aureus carriage, was associated with poly-sensitization to food and inhalant allergens. SE-sensitized participants had higher median specific IgE to inhalant allergens (41.4 kU_A /L, IQR 10.1-118.4) compared to non-SE-sensitized participants (18.0 kU_A /L, IQR 5.5-48.6, P=.004), but not to food allergens. SE sensitization was associated with allergic multimorbidity.

CONCLUSION

Sensitization to SEs may play a role in the development of allergen poly-sensitization and allergic multimorbidity.

Allergic disease and Staphylococcus aureus carriage in adolescents in the Arctic region of Norway

BACKGROUND

Allergic diseases are common chronic diseases in children and adolescents, but limited epidemiological data are available during transition into adulthood. Nasal Staphylococcus aureus carriage has been linked to increased prevalence of allergic disease. The objective of this study was to define the prevalence of allergic diseases in adolescents above the Arctic Circle in Northern Norway and to study the associations of S. aureus carriage with allergic diseases.

METHODS

A school-based cohort in late adolescence (18-19 years) was invited to participate in a cross-sectional study on lifestyle and health, and 868 attended (71.9%). Self-reported allergic disease and severity of eczema were assessed by Mechanisms of the Development of Allergy and Patient-Oriented Eczema Measure questionnaires. Participants were tested with spirometry and exhaled nitric oxide (FeNO) and swabbed for bacterial culture from nose and eczematous skin.

RESULTS

We found asthma, eczema, allergic rhinitis (AR), and nasal S. aureus carriage among 11.9%, 10.4%, 26.0%, and 51.3% of the participants, respectively, and 10.2% had allergic multimorbidity. Lifetime prevalence for any allergic disease was 45.1%. Reduced lung function and increased FeNO were found in 11.6% and 22.1% in participants with asthma, respectively. Nasal S. aureus carriage was associated with eczema, severe asthma, and severe AR. FeNO > 25 ppb was associated with both asthma and nasal S. aureus carriage.

CONCLUSION

Asthma, eczema, and AR are common among adolescents above the Arctic Circle in Norway. Allergic disease is associated with S. aureus carriage, but its role in the pathogenesis and severity is not established.

Strategies targeting the IL-4/IL-13 axes in disease

IL-4 and IL-13 are pleiotropic Th2 cytokines produced by a wide variety of different cell types and responsible for a broad range of biology and functions. Physiologically, Th2 cytokines are known to mediate host defense against parasites but they can also trigger disease if their activities are dysregulated. In this review we discuss the rationale for targeting the IL-4/IL-13 axes in asthma, atopic dermatitis, allergic rhinitis, COPD, cancer, inflammatory bowel disease, autoimmune disease and fibrotic disease as well as evaluating the associated clinical data derived from blocking IL-4, IL-13 or IL-4 and IL-13 together.

Involvement of Staphylococcus aureus and Moraxella catarrhalis in Japanese cedar pollinosis

BACKGROUND AND OBJECTIVE

From mid February to the end of March, each year ∼30% of Japanese have Japanese cedar pollinosis. Moreover, 10-50% of patients with this pollinosis exhibit nasal manifestations in the preseason. These patients have a predominance of neutrophils but not eosinophils in nasal swabs and high carriage of Staphylococcus aureus. We hypothesized that S. aureus or other bacteria and associated neutrophilia were involved in preseasonal symptoms.

METHODS

Cytology and bacterial colony growth were assessed in nasal swabs in the groups of asymptomatic patients in the preseason (PreAsP) (n = 53) and symptomatic patients in the preseason (PreSyP) (n = 60), and in group of symptomatic patients in season (InSyP) (n = 72).

RESULTS

In the preseason, high neutrophilia was present in only 20% of the PreAsP group but in 47% of the PreSyP group (p < 0.01). Nasal carriage of S. aureus in the PreAsP and PreSyP groups were 79%, 75%, respectively, whereas, for Moraxella catarrhalis, these were 9% versus 25% (PreAsP versus PreSyP group; p < 0.05). In patients with positive results for S. aureus and M. catarrhalis, the degrees of neutrophilia (-, ±, +, 2+, 3+) in the PreSyP group were larger than in the PreAsP groups (p < 0.01). In the PreSyP group, the magnitude of neutrophilia was greater (p < 0.05) in subgroups with more colonies of S. aureus than in subgroups with fewer colonies.

CONCLUSION

Nasal symptoms in the preseason are associated with neutrophilia and nasal colonization with S. aureus and M. catarrhalis. Patients with symptoms in the preseason had improved symptom scores when given prophylactic treatment early in season but had more-severe symptom scores late in season than asymptomatic patients in the preseason. Neutrophil-associated tissue damage related to bacterial colonization may underlie these associations.

Risks for infection in patients with asthma (or other atopic conditions): is asthma more than a chronic airway disease?

Most of the research effort regarding asthma has been devoted to its causes, therapy, and prognosis. There is also evidence that the presence of asthma can influence patients' susceptibility to infections, yet research in this aspect of asthma has been limited. There is additional debate in this field, with current literature tending to view the increased risk of infection among atopic patients as caused by opportunistic infections secondary to airway inflammation, especially in patients with severe atopic diseases. However, other evidence suggests that such risk and its underlying immune dysfunction might be a phenotypic or clinical feature of atopic conditions. This review argues (1) that improved understanding of the effects of asthma or other atopic conditions on the risk of microbial infections will bring important and new perspectives to clinical practice, research, and public health concerning atopic conditions and (2) that research efforts into the causes and effects of asthma must be juxtaposed because they are likely to guide each other.

The who, where, and when of IgE in allergic airway disease

Allergic asthma and allergic rhinitis/conjunctivitis are characterized by a T(H)2-dominated immune response associated with increased serum IgE levels in response to inhaled allergens. Because IgE is a key player in the induction and maintenance of allergic inflammation, it represents a prime target for therapeutic intervention. However, our understanding of IgE biology remains fragmentary. This article puts together our current knowledge on IgE in allergic airway diseases with a special focus on the identity of IgE-secreting cells ("who"), their location ("where"), and the circumstances in which they are induced ("when"). We further consider the therapeutic implications of the insights gained.

Does allergy impair innate immunity? Leads and lessons from atopic dermatitis

Host defence responses against invading pathogens are well-balanced, inflammatory processes of the innate and adaptive immune system. Impaired development or abnormal function of either system can result in failure to control pathogens and to clear infections. Infections have been claimed to modulate the onset and course of allergic diseases. This so-called hygiene hypothesis is still an active area of research. In contrast, the effects of allergies on infections and pathogen-directed immune responses are less well understood. Here, we have reviewed the existing evidence that allergies result in impaired innate immunity and we discuss recent observations that may explain why and how innate immunity is dysfunctional in allergic patients. With a focus on atopic dermatitis as a model of allergic disease, we speculate that one of the key features of allergic conditions, namely Th2 polarization, leads to several independent inhibitory effects on host defence and consequently to a higher risk of infections in allergic patients. A better understanding of impaired host defence and its mechanisms in allergic subjects will help to improve the management of these diseases.

Superantigens

Superantigens (SAgs) are derived from diverse sources, including bacteria, viruses, and human hepatic tissue. SAgs initially cause lymphocyte activation but then result in clonal deletion and anergy, leading to immune tolerance. They can also act as superallergens by stimulating a broad spectrum of mast cells and basophils in patients with allergic conditions. The newly described staphylococcal SAg-like proteins subvert innate immune function by several mechanisms, which are distinct from SAgs' effects on lymphocytes and other acquired immune processes. There is mounting evidence to suggest that SAgs play a role in the pathophysiology of inflammatory airway disease. The pathophysiologic role of SAg-like proteins awaits clarification.

[Diagnosis, therapy and current research aspects of selected chronic inflammatory diseases with head and neck involvement]

Wegener's granulomatosis, Churg-Strauss syndrome and analgesics intolerance syndrome with polyps demonstrate non-specific manifestations in the head and neck region. These symptoms can often lead to early diagnosis and initiation of the correct therapy. However, symptoms are often ambiguous and many rare differential diagnoses must be borne in mind. This clinical picture presents a challenge for the otorhinolaryngologist, who is commonly the first contacted physician. Diagnostics and therapy have to be carried out in an interdisciplinary approach between rheumatologist, pulmonologist, pathologist, radiologist, ophthalmologist, infection specialist and nephrologist. Despite significant scientific and therapeutic advances, these diseases remain incurable. In recent decades they have lost their life-threatening character (Wegener's granulomatosis) and are now chronically relapsing diseases. Their aetiology, however, is still unclear and treatment leads to a wide spectrum of undesirable effects. Research work is needed to advance diagnostics and therapy in this field. Recent research aspects are presented in this article.

Staphylococcus aureus in nasal lavage and biopsy of patients with chronic rhinosinusitis

BACKGROUND

Staphylococcus aureus may play a relevant etiologic role in chronic rhinosinusitis (CRS) and may explain the T(H2) shift observed in CRS with nasal polyps (CRSNP(+)). Naturally occurring S. aureus small colony variants (SASCV) escape immune surveillance, antibiotic treatment and microbiologic routine diagnostic techniques. The frequency of S. aureus and SASCV in CRS patients and S. aureus-related effects on the local immune response should be prospectively investigated.

METHODS

Nasal lavages and mucosal biopsies of CRS patients were examined with bacterial culture suitable for detecting SASCV, real time PCR and fluorescence in situ hybridization. To assess the effects of S. aureus positivity, interleukin-5 (IL-5), interferon-gamma, total immunoglobulin E (IgE), eotaxin, granulocyte-colony stimulating factor, and eosinophil cationic protein in nasal lavages were determined and gene transcription analysis of nasal biopsies from S. aureus positive and negative CRSNP(+) patients was performed.

RESULTS

Thirty-one CRSNP(+) patients, 13 CRS patients without polyps, and 21 control patients were evaluated. Staphylococcus aureus was detected by any method in 25 patients (39%). Staphylococcus aureus detection rates did not differ between the three disease groups (P = 0.3). Staphylococcus aureus small colony variants were not found. In nasal lavages, IL-5 and total IgE levels were higher in CRSNP(+) patients than in CRSNP(-) patients or controls (P < 0.05). Staphylococcus aureus positivity did not influence biomarker concentrations in nasal lavages. Genes for T(H2) cytokines were not differentially transcribed.

CONCLUSIONS

We could not observe a higher prevalence of S. aureus in CRS patients with or without nasal polyps than in controls. We could not substantiate that S. aureus intensifies the T(H2) shift in CRSNP(+) patients. Staphylococcus aureus small colony variants were not detected in any sample.

Efficacy of nasal Staphylococcus aureus eradication by topical nasal mupirocin in patients with perennial allergic rhinitis

BACKGROUND

Staphylococcus aureus (SA) colonization is frequent in patients with perennial allergic rhinitis (PAR). Mupirocin has well-recognized antistaphylococcal activity, and its nasal formulation is approved for the eradication of SA nasal colonization.

OBJECTIVE

To investigate the frequency of SA nasal carriage, its possible influence on AR severity, and nasal mupirocin's role on AR clinical severity.

METHODS

Sixty patients, aged 5 to 60 years, with AR were included, and 55 healthy individuals served as a control group. Nasal smear specimens were drawn from both nares. A skin prick test to inhalational allergens and a score-graded clinical evaluation of AR were performed. Carriers of SA were treated with topical nasal mupirocin.

RESULTS

The SA carrier (SAC) state was found in 23 (38%) of the patients with AR and in 8 (15%) of the healthy controls (P = .004). Comparing SACs with AR SA noncarriers, nasal symptom scores (SSs) tended to be higher in the SAC group (mean [SD], 11.09 [2.16] vs 8.86 [1.43]; P < .005). Treatment with topical nasal mupirocin diminished the SAC state to 10% (P = .009) but did not change AR clinical severity, as assessed by the SS.

CONCLUSIONS

In patients with PAR, the SAC state is more prevalent compared with the healthy population. Topical nasal mupirocin reduces the SAC state but fails to clinically improve PAR, as assessed by the SS.

Aggravation of bronchial eosinophilia in mice by nasal and bronchial exposure to Staphylococcus aureus enterotoxin B

BACKGROUND

The role of bacterial enterotoxins like Staphylococcus aureus enterotoxin B (SEB) in allergic asthma remains unknown. We used a mouse model of airway allergy to study the effects of nasal or bronchial contact with SEB on bronchial allergic inflammation.

METHODS

The features of allergic asthma were induced in ovalbumin (OVA)-sensitized mice (days 1-13) by repeated exposures to nebulized OVA (days 33-37). Nasal or bronchial application of SEB was performed on three occasions (days 33-35-37), and the effects on bronchial inflammation, IgE titres and expression levels of mRNA for T helper type 2 cytokines and other inflammatory mediators were evaluated.

RESULTS

Both nasal and bronchial SEB enhanced the allergen-induced bronchial inflammation, as reflected by more eosinophilic inflammation in the airway lumen and in bronchial tissue. Aggravation of experimental asthma correlated with higher expression of mRNA for IL-5, IL-4, IFN-gamma, IL-12 p40, eotaxin-1 and TGF-beta in bronchi. In addition, nasal SEB elevated concentrations of IL-4, IL-5 and IFN-gamma in serum and bronchial SEB increased titres of OVA-specific and total IgE in serum.

CONCLUSION

Our data illustrate the potential of both nasal as well as bronchial SEB to aggravate several features of allergic asthma in a mouse model.

Staphylococcus aureus sensitization and allergic disease in early childhood: Population-based birth cohort study

BACKGROUND

Staphylococcus aureus-secreted enterotoxins (SEs) may be involved in the pathophysiology of atopic diseases.

OBJECTIVE

We investigated the role of SEs in allergic diseases during early childhood (using the mixture of SE-specific IgEs [SE-mix] as a marker).

METHODS

Children (N = 510) were followed from birth to age 5 years (repeated questionnaires, IgE to inhalant and food allergens, lung function [spirometry, plethysmography], airway reactivity [dry air challenge]). We measured SE-mix specific IgE (SE-A, SE-C, toxic shock syndrome toxin 1) by using fluorescence immunoassay.

RESULTS

We found no association between rhinitis and SE-mix sensitization. Children with eczema were more frequently SE-mix-sensitized than children without (17.4% vs 8.3%; P = .02). SE-mix sensitization rate increased significantly with increasing eczema severity (no eczema, mild, moderate/severe: 8.3%, 14.8%, 42.9%; P = .003) and remained independently associated with eczema in a multivariate model adjusting for total IgE (adjusted odds ratio, 2.19; 95% CI, 1.05-4.56; P = .04). SE-mix sensitization was associated with current wheeze in the univariate but not the multivariate model. Among wheeze phenotypes, persistent wheezers were most commonly sensitized to SE-mix (never, transient, late-onset, persistent: 8.5%, 3.8%, 7.7%, 17.6%; P = .05). Among wheezers, those SE-mix-sensitized had significantly higher airway reactivity compared with those nonsensitized (mean FEV(1) change, mL [95% CI]: -59 [-121, 3] vs 19 [-10.2, 48.9]; P = .04), with little difference after adjusting for atopy.

CONCLUSION

We found differences in SE-mix IgE antibodies between healthy 5-year-old children and children with eczema and wheeze. The proportion of patients sensitized to SE-mix increases with increasing disease severity.

CLINICAL IMPLICATIONS

Staphylococcal enterotoxins are potential modifiers of childhood wheeze and eczema.

Nasal carriage of Staphylococcus aureus in children with allergic rhinitis and the effect of intranasal fluticasone propionate treatment on carriage status

OBJECTIVE

The aim of this study is to determine the rate of nasal carriage of Staphylococcus aureus (NCSA) in children with allergic rhinitis (AR) and to determine the effect of intranasal fluticasone propionate spray on the NCSA.

PATIENTS AND METHODS

Nasal swabs were taken from the children admitted to general pediatrics and pediatric pulmonology clinics. Patients were divided into two groups according to the presence or absence of AR. Diagnosis of AR was based on the patient's symptoms. Nasal swabs were taken from AR patients before and after the treatment with intranasal fluticasone propionate, and from the control group at the beginning and after 2 months.

RESULTS

Whole NCSA rate was 17.9%; it was 21.4% for AR patients and 15.9% for control group, respectively (p>0.05). Treatment with intranasal fluticasone propionate spray did not influence NCSA in AR patients.

CONCLUSION

It seemed that NCSA was not increased in children with AR and treatment with intranasal fluticasone propionate spray did not change NCSA in AR patients. It is obvious that better understanding of the factors affecting the acquisition and loss of NCSA might increase our knowledge about the relationship between NCSA, allergic airway diseases and their treatments.

Germinal-centre reactions in allergic inflammation

Primary and secondary immune responses in the germinal centres of lymphoid organs have been studied in the past. There is now compelling evidence of a third stage in the immune response, in 'tertiary lymphoid organs' that develop at sites of chronic inflammation in response to persistent local antigen challenge. Germinal-centre-like reactions are well-documented in the target organs of autoimmune diseases. Here, we review recent evidence that they also occur at sites of allergic inflammation.

Human airway and peripheral blood eosinophils enhance Th1 and Th2 cytokine secretion

BACKGROUND

The effector function of eosinophils involves their release of toxic granule proteins, reactive oxygen species, cytokines, and lipid mediators. Murine studies have demonstrated that eosinophils can also enhance T cell function. Whether human eosinophils, in particular, airway eosinophils, have similar immunoregulatory activity has not been fully investigated. The aim of this study was to determine whether human blood and airway eosinophils can contribute to Th1 and Th2 cytokine generation from CD4+ T cells stimulated with superantigen.

METHODS

Eosinophils were obtained from blood or bronchoalveolar lavage fluid 48 h after segmental allergen bronchoprovocation. Purified eosinophils were co-cultured with autologous CD4+ blood T cells in the presence of staphylococcal enterotoxin B (SEB). Cytokine levels in the supernatant fluid were determined by enzyme-linked immunosorbent assay (ELISA). Eosinophil expression of major histocompatibility complex (MHC) class II and co-stimulatory molecules was assessed by flow cytometry before culture, 24 h after granulocyte-macrophage colony-stimulating factor (GM-CSF) stimulation, and 24 h after co-culture with CD4+ T cells and SEB.

RESULTS

Interleukin (IL)-5, IL-13, and interferon (IFN)-gamma generation increased when CD4+ T cells were co-cultured with either blood or airway eosinophils in the presence of SEB. The ability of eosinophils to enhance cytokine generation was independent of their source (blood vs airway), activation by GM-CSF, or detectable expression of human leukocyte antigen (HLA)-DR, CD80, or CD86.

CONCLUSION

Our data demonstrate that SEB-induced generation of Th1 and Th2 cytokines is increased in the presence of human blood and airway eosinophils. Thus, eosinophils can have an immunoregulatory function in pathogen-associated allergic diseases such as atopic dermatitis, chronic sinusitis, and asthma exacerbations.