Increased risk of serious pneumococcal disease in patients with atopic conditions other than asthma

Risk of herpesvirus, serious, and opportunistic infections in atopic dermatitis: a population-based cohort study

BACKGROUND

Staphylococcal and herpes simplex virus (HSV) infections are commonly recognized in atopic dermatitis (AD) but less is known about other types of infections.

OBJECTIVES

To determine the risk of herpesvirus infections, serious infections, and opportunistic infections in patients with AD.

METHODS

We conducted a population-based cohort study using UK-based electronic medical records data. Patients with AD were each matched to up to 5 unaffected patients on age, practice, and index date. AD severity was defined using treatments. The outcomes were incident herpesvirus infections (cytomegalovirus [CMV], Epstein-Barr virus [EBV], HSV, or varicella zoster virus [VZV]), serious infections, and opportunistic infections.

RESULTS

409,431 children and 625,083 adults with AD were matched to 1,809,029 children and 2,678,888 adults without AD, respectively. In adjusted Cox regression models, children and adults with AD had 50-52% greater risk of HSV and 18-33% greater risk of VZV, with risk increasing in parallel with AD severity. CMV risk was elevated among children with AD (HR 2.50 [1.38-4.54]) and adults with severe AD (4.45 [1.76-11.25]). Patients with AD had 26-40% increase in risk of serious infections, with severe AD carrying greatest risk. Although rare, opportunistic infections were not associated with AD in children but were associated with all severities of AD in adults (overall HR 1.31 [1.20-1.42]). All estimates remained consistent after excluding patients receiving immunosuppressive treatments for AD.

CONCLUSIONS

AD is significantly associated with herpesvirus infections, serious infections, and opportunistic infections in a dose-responsive manner with severity. AD may increase susceptibility to infections exclusive of immunosuppressive medications.

Factors associated with IgG levels in adults with IgG subclass deficiency

Background

Factors associated with IgG levels in adults with IgG subclass deficiency (IgGSD) are incompletely understood. We studied adults with IgGSD with subnormal IgG1 only, subnormal IgG1/IgG3, or subnormal IgG3 only without other subnormal IgG subclasses, IgA, or IgM. We compiled: age; sex; autoimmune condition(s) (AC); atopy; IgG, IgG subclasses, IgA, IgM; IgGsum (IgG1 + IgG2 + IgG3 + IgG4); and D (percentage difference between IgGsum and IgG). We compared attributes of patients with/without subnormal IgG (< 7.00 g/L; subnormal IgG1 subclass groups only) and analyzed IgGsum and IgG relationships. We performed backward stepwise regressions on IgG using independent variables IgG subclasses, age, and sex and on D using independent variables age and sex.

Results

There were 39 patients with subnormal IgG1 only (89.7% women), 53 with subnormal IgG1/IgG3 (88.7% women), and 115 with subnormal IgG3 only (91.3% women). Fifteen patients (38.5%) and 32 patients (60.4%) in the respective subnormal IgG1 subclass groups had subnormal IgG. Attributes of patients with/without IgG < 7.00 g/L were similar, except that AC prevalence was lower in patients with subnormal IgG1 only and IgG < 7.00 g/L than ≥ 7.00 g/L (p = 0.0484). Mean/median IgG1 and IgG2 were significantly lower in patients with IgG < 7.00 g/L in both subnormal IgG1 subclass groups (p < 0.0001, all comparisons). Regressions on IgG in three subclass groups revealed positive associations with IgG1 and IgG2 (p < 0.0001 each association). Regressions on D revealed no significant association. IgG1 percentages of IgGsum were lower and IgG2 percentages were higher in patients with subnormal IgG1 subclass levels than subnormal IgG3 only (p < 0.0001 all comparisons).

Conclusions

We conclude that both IgG1 and IgG2 are major determinants of IgG in patients with subnormal IgG1, combined subnormal IgG1/IgG3, or subnormal IgG3 and that in patients with subnormal IgG1 or combined subnormal IgG1/IgG3, median IgG2 levels are significantly lower in those with IgG < 7.00 g/L than those with IgG ≥ 7.00 g/L.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12865-021-00447-3.

Association between nasal and nasopharyngeal bacterial colonization in early life and eczema phenotypes

Background

An association has been reported between early life Staphylococcus aureus nasal carriage and higher risk of childhood eczema, but it is unclear whether this relationship is causal and associations with other bacterial species are unclear.

Objective

To examine the associations of early life nasal and nasopharyngeal bacterial carriage with eczema phenotypes, and the direction of any associations identified.

Methods

Among 996 subjects of a population‐based prospective cohort study, nasal swabs for Staphylococcus  aureus, and nasopharyngeal swabs for Streptococcus pneumoniae, Moraxella catarrhalis and Haemophilus influenzae were collected and cultured from age 6 weeks to 6 years. Never, early, mid‐, late transient and persistent eczema phenotypes were identified from parental‐reported physician‐diagnosed eczema from age 6 months until 10 years. Multinomial regression models and cross‐lagged models were applied.

Results

Staphylococcus aureus nasal carriage at 6 months was associated with an increased risk of early transient and persistent eczema (OR (95% CI): 2.69 (1.34, 5.39) and 4.17 (1.12, 15.51)). The associations between Staphylococcus aureus nasal carriage and eczema were mostly cross‐sectional, and not longitudinal. No associations of Staphylococcus pneumoniae, Moraxella catarrhalis and Haemophilus influenza nasopharyngeal bacterial carriage with eczema and eczema phenotypes were observed (OR range (95% CI): 0.71 (0.35, 1.44) to 1.77 (0.84, 3.73)).

Conclusions

Early life Staphylococcus aureus nasal carriage, but not Staphylococcus pneumoniae, Moraxella catarrhalis and Haemophilus influenza nasopharyngeal carriage, was associated with early transient and persistent eczema. Staphylococcus aureus nasal carriage and eczema were mostly cross‐sectionally associated, and not longitudinally, making a causal relationship in either direction unlikely.

Pneumococcal Vaccine in Adult Asthma Patients

Streptococcus pneumoniae is the most frequent source of community-acquired bacterial pneumonia in adults. Respiratory tract infections are the foremost reasons for asthma exacerbations. The World Health Organization and the Centers for Disease Control and Prevention consider asthma a clear indication for pneumococcal vaccination. The aim of this study was to determine the extent to which adult patients with asthma in Poland adhere to a schedule of recommended pneumococcal vaccinations. In addition, the study attempted to assess the source of the patient knowledge on vaccination and the plausible determents for vaccination. The study was conducted among patients at specialist outpatient clinics in the form of an anonymous survey that contained questions about asthma, vaccines, and the knowledge and motivations. A total of 214 patients (149 females and 65 males) of the mean age of 52 ± 17 years were interviewed. A staggering 93% of patients did not receive pneumococcal vaccination, and only 24% of patients were aware of the need for this vaccine. Age, gender, and education did not affect whether patients chose to receive the vaccine. The most often quoted reason for not receiving the vaccine was lack of information, followed by lack of faith in vaccine efficacy, and the fear of adverse effects. From the standpoint of health hazard stemming from prophylaxis avoidance, it appears paramount to educate asthmatic patients on the benefits of receiving pneumococcal vaccination.

[Value of absolute counts of lymphocyte subsets in the early prediction of refractory Mycoplasma pneumoniae pneumonia in children]

OBJECTIVE

To study the value of absolute counts of lymphocyte subsets in the early prediction of refractory Mycoplasma pneumoniae pneumonia (RMPP) in children.

METHODS

A retrospective analysis was performed for the clinical data of 244 children with Mycoplasma pneumoniae pneumonia (MPP). Among these children, 166 had MPP, and 58 had RMPP. The two groups were compared in terms of clinical features and laboratory markers such as lymphocyte subsets, lactate dehydrogenase, C-reactive protein, procalcitonin and immunoglobulin E (IgE). The receiver operating characteristic (ROC) curve was used to evaluate the specific indices for predicting RMMP.

RESULTS

There were significant differences between the two groups in the absolute counts of CD3⁺, CD4⁺, CD19⁺, and CD56⁺ lymphocytes and the serum levels of lactate dehydrogenase, C-reactive protein, and IgE (P<0.05). The ROC curve analysis showed that the absolute counts of CD3⁺, CD4⁺ and CD19⁺ lymphocytes had an area under the ROC curve (AUC) of 0.866, 0.900 and 0.842 respectively in the differential diagnosis of RMPP and MPP, with a sensitivity of 86%, 90% and 82% respectively and a specificity of 75%, 70% and 80% respectively.

CONCLUSIONS

The absolute counts of CD3⁺, CD4⁺ and CD19⁺ lymphocytes can be used to predict RMPP in children.

Allergic asthma is associated with increased risk of infections requiring antibiotics

BACKGROUND

Viral infection and allergy have been identified as major risk factors for exacerbation in asthma, especially in the presence of both. However, whether patients with allergic asthma are more susceptible to respiratory infections requiring antibiotics remains unknown.

OBJECTIVE

To investigate allergy as a risk factor for respiratory infections requiring antibiotics based on register data from a nationwide population of patients with asthma.

METHODS

A register-based prospective follow-up study was performed using the Danish prescription database. In the inclusion period from 2010 through 2011, we identified patients with allergic asthma 18 to 44 years old. Patients were investigated during the follow-up period from 2012 through 2013, depending on their prescription drug use of antiallergic medication and antibiotics. Odds ratios were adjusted for age, sex, asthma severity, education, and urban vs rural residence.

RESULTS

In a nationwide population we identified 60,415 patients with asthma. Based on prescriptions fillings for antiallergic medication, patients were subdivided into (1) nonallergic asthma (n = 35,334, 51.5%) and (2) allergic asthma (n = 25,081, 48.5%). Allergic asthma was associated with an increased risk of filling at least 2 antibiotic prescriptions per year compared with nonallergic asthma (odds ratio 1.28, 95% confidence interval 1.24-1.33, P < .0001). Interestingly, a subgroup analysis showed a protective effect of immunotherapy against the risk of requiring antibiotics (odds ratio 0.76, 95% confidence interval 0.66-0.87, P = .0001).

CONCLUSION

Patients with allergic asthma have an increased risk of being prescribed antibiotics for respiratory infections compared with those with nonallergic asthma. Treatment with allergen immunotherapy appears to have a protective effect against this risk.

Major Comorbidities of Atopic Dermatitis: Beyond Allergic Disorders

The consequences of atopic dermatitis reach beyond the skin and past childhood. Patients with atopic dermatitis are at risk of developing allergic comorbidities, but less is known about the associations between atopic dermatitis and non-allergic conditions. Understanding these non-allergic comorbidities has the potential to improve patient outcomes and to help mitigate the cost and burdens associated with these conditions. Atopic dermatitis is associated with cutaneous bacterial infections, more severe forms/courses of cutaneous viral infections, and extra-cutaneous infections. Atopic dermatitis is also associated with several mental health comorbidities particularly attention-deficit hyperactivity disorder, anxiety, and depression. Data are largely inconsistent for specific cancers, but atopic dermatitis appears to protect against malignancy overall; severe long-term atopic dermatitis is associated with adult lymphomas. Atopic dermatitis may also be associated with obesity, cardiovascular disease, and autoimmune disease, particularly alopecia areata and gastrointestinal immune-mediated disorders. Although the causative mechanisms underlying these associations are poorly understood, treating physicians should be aware of associations in seeking to alleviate the burden for patients with atopic dermatitis.

Longitudinal Associations Between Respiratory Infections and Asthma in Young Children

We examined temporal dependencies between repeated assessments of respiratory tract infections (RTIs) and asthma in children in the Leicester Respiratory Cohort, Leicestershire, United Kingdom. Information associated with asthma (i.e., doctor diagnosis, health care visits, wheeze frequency) and RTIs (i.e., cold duration and frequency, cough with colds, ear infections) in the previous 12 months was assessed repeatedly at ages 1, 4, and 6 years for children born between April 1996 and April 1997. We determined associations between contemporaneous and lagged measures of asthma and RTIs, using structural equation modelling. In 1,995 children, asthma was positively associated with contemporaneous infections. Asthma at age 6 years was positively associated with asthma at age 4 years (regression coefficient = 0.87; 95% confidence interval (CI): 0.76, 0.97), but not with asthma at age 1 year (regression coefficient = -0.01; 95% CI: -0.14, 0.11). We found no evidence for direct protective effect of infections at age 1 year on asthma either at age 4 (regression coefficient = -0.20; 95% CI: -0.51, 0.10) or 6 (regression coefficient = 0.24; 95% CI: -0.04, 0.52) years. Adjusting for potential confounders did not qualitatively change those relationships. Based on our findings, we suggest that asthma at age 6 years is directly influenced by asthma history and only indirectly, if at all, by earlier infection episodes. We found little support for a protective effect of preschool infections on asthma at early school age.

Streptococcus pneumoniae's Virulence and Host Immunity: Aging, Diagnostics, and Prevention

Streptococcus pneumoniae is an infectious pathogen responsible for millions of deaths worldwide. Diseases caused by this bacterium are classified as pneumococcal diseases. This pathogen colonizes the nasopharynx of its host asymptomatically, but overtime can migrate to sterile tissues and organs and cause infections. Pneumonia is currently the most common pneumococcal disease. Pneumococcal pneumonia is a global health concern and vastly affects children under the age of five as well as the elderly and individuals with pre-existing health conditions. S. pneumoniae has a large selection of virulence factors that promote adherence, invasion of host tissues, and allows it to escape host immune defenses. A clear understanding of S. pneumoniae's virulence factors, host immune responses, and examining the current techniques available for diagnosis, treatment, and disease prevention will allow for better regulation of the pathogen and its diseases. In terms of disease prevention, other considerations must include the effects of age on responses to vaccines and vaccine efficacy. Ongoing work aims to improve on current vaccination paradigms by including the use of serotype-independent vaccines, such as protein and whole cell vaccines. Extending our knowledge of the biology of, and associated host immune response to S. pneumoniae is paramount for our improvement of pneumococcal disease diagnosis, treatment, and improvement of patient outlook.

Does atopy affect the course of viral pneumonia?

Background

The presence of atopy is considered as a risk factor for severe respiratory symptoms in children. The objective of this study was to examine the effect of atopy on the course of disease in children hospitalised with viral pneumonia.

Methods

Children between the ages of 1 and 6 years hospitalised due to viral pneumonia between the years of 2013 and 2016 were included to this multicentre study. Patients were classified into two groups as mild–moderate and severe according to the course of pneumonia. Presence of atopy was evaluated with skin prick tests. Groups were compared to evaluate the risk factors associated with severe viral pneumonia.

Results

A total of 280 patients from nine centres were included in the study. Of these patients, 163 (58.2%) were male. Respiratory syncytial virus (29.7%), Influenza A (20.5%), rhinovirus (18.9%), adenovirus (10%), human metapneumovirus (8%), parainfluenza (5.2%), coronavirus (6%), and bocavirus (1.6%) were isolated from respiratory samples. Eighty-five (30.4%) children had severe pneumonia. Atopic sensitisation was found in 21.4% of the patients. Ever wheezing (RR: 1.6, 95% CI: 1.1–2.4), parental asthma (RR: 1.5, 95% CI: 1.1–2.2), other allergic diseases in the family (RR: 1.8, 95% CI: 1.2–2.9) and environmental tobacco smoke (RR: 1.6, 95% CI: 1.1–3.5) were more common in the severe pneumonia group.

Conclusions

When patients with mild–moderate pneumonia were compared to patients with severe pneumonia, frequency of atopy was not different between the two groups. However, parental asthma, ever wheezing and environmental tobacco smoke exposure are risk factors for severe viral pneumonia in children.

Asthma, other atopic conditions and risk of infections in 105 519 general population never and ever smokers

BACKGROUND

Individuals with atopic conditions may have increased susceptibility to infections outside the organs directly affected by their atopic condition.

OBJECTIVE

We tested the hypothesis that atopic conditions overall, and stratified by smoking history, are associated with increased risk of hospitalization for infections.

METHODS

We collected information on smoking history and self-reported atopic conditions from 105 519 individuals from the general population and followed them for up to 23 years for infectious disease hospitalizations and deaths. For asthma, we focused on never smokers with asthma diagnosed before age 50 (early asthma) to minimize confounding by chronic obstructive pulmonary disease.

RESULTS

During follow-up, 11 160 individuals had infections. Never smokers with early asthma versus no atopic conditions had significantly increased risks of any infection (hazard ratio 1.65; 95% confidence interval 1.40-1.94), pneumonia (2.44; 1.92-3.11) and any non-respiratory tract infection (1.36; 1.11-1.67); results were similar in ever smokers. Never smokers with any asthma had significantly increased risks of any infection (1.44; 1.24-1.66) and pneumonia (1.99; 1.62-2.44). Neither atopic dermatitis (1.00; 0.91-1.10) nor hay fever (1.00; 0.93-1.07) was associated with risk of any infection. In never smokers, risk estimates for any infection were comparable between asthma and diabetes, as were the population attributable fractions of 2.2% for any asthma and 2.9% for diabetes.

CONCLUSION

Early asthma was associated with significantly increased risks of any infection, pneumonia and any non-respiratory tract infection in never and ever smokers. In never smokers, risk estimates as well as population attributable fractions for any infection were comparable between asthma and diabetes, suggesting that asthma may be a substantial risk factor for infections in the general population.

A new approach to the classification and management of airways diseases: identification of treatable traits

This review outlines a new, personalized approach for the classification and management of airway diseases. The current approach to airways disease is, we believe, no longer fit for purpose. It is impractical, overgeneralizes complex and heterogeneous conditions and results in management that is imprecise and outcomes that are worse than they could be. Importantly, the assumptions we make when applying a diagnostic label have impeded new drug discovery and will continue to do so unless we change our approach. This review suggests a new mechanism-based approach where the emphasis is on identification of key causal mechanisms and targeted intervention with treatment based on possession of the relevant mechanism rather than an arbitrary label. We highlight several treatable traits and suggest how they can be identified and managed in different healthcare settings.

IgE sensitization to inhalant allergens and the risk of airway infection and disease: A population-based study

BACKGROUND

Immunoglobulin E (IgE) sensitization, which is the propensity to develop IgE antibodies against common environmental allergens, is associated with a lymphocyte T-helper type 2 (Th2) skewed immune response and a high risk of allergic respiratory disease. Little is known about whether IgE sensitization confers an increased risk of respiratory infections in adults. We investigated the association between IgE sensitization and the incidence of acute airway infections, other infections and chronic lower airway disease events as recorded in nation-wide registries.

METHODS

We included 14,849 persons from five population-based studies with measurements of serum specific IgE positivity against inhalant allergens. Participants were followed by linkage to Danish national registries (median follow-up time 11.3 years). The study-specific relative risks were estimated by Cox regression analysis, meta-analysed, and expressed as hazard ratios, HRs (95% confidence intervals, CIs).

RESULTS

The relative risks for IgE sensitized vs. non-sensitized were: for pneumonia (HR = 1.20, 95% CI: 1.01, 1.41), other acute airway infection (HR = 0.86, 95% CI: 0.60, 1.22), infection (HR = 1.06, 95% CI: 0.90, 1.24), asthma (HR = 2.26, 95% CI: 1.79, 2.86), and other chronic lower airway disease (HR = 1.31, 95% CI: 1.08, 1.58). In never smokers, the higher risk of pneumonia (HR = 1.73, 95% CI: 1.23, 2.44) and asthma (HR = 3.17, 95% CI: 2.10, 4.76) among IgE sensitized was more pronounced.

CONCLUSIONS

IgE sensitization was associated with a higher risk of asthma, other chronic lower airway diseases, and pneumonia. However, the association between IgE sensitization and pneumonia may be explained by undiagnosed asthma causing the pneumonia. Further studies are needed for confirmation.

Adult Atopic Dermatitis with Comorbid Atopic Disease is Associated with Increased Risk of Infections: A Population-Based Cross-Sectional Study

Introduction

Atopic dermatitis (AD) is related to other atopic diseases asthma and allergic rhinitis. It is known that those with asthma or allergic rhinitis have impaired immune responses that may predispose them to infections. This study sought to determine whether adult AD is associated with systemic infections, and whether association is strengthened in those with AD plus another atopic disease.

Methods

This cross-sectional study obtained information from adults in the 2010 and the 2012 National Health Interview Survey (NHIS). The primary exposure was history of AD without or with an additional atopic disease, asthma or allergic rhinitis. Self-reported systemic infections were the primary outcomes. Survey logistic regression was performed and adjusted odds ratios (aOR) reported.

Results

AD in NHIS 2010 was associated with increased risk of sinusitis [aOR (95% CIs): 1.65 (1.42, 1.91), P < 0.001], head or chest cold [1.31 (1.12, 1.52), P < 0.001], and gastrointestinal illness [2.39 (1.97, 2.89), P < 0.001], and in NHIS 2012, pneumonia/influenza [1.73 (1.54, 1.95), P < 0.001], strep throat/tonsillitis [1.72 (1.54, 1.92), P < 0.001], sinusitis [1.77 (1.54, 2.02), P < 0.001], head or chest cold [1.49 (1.33, 1.67), P < 0.001], and infectious disease [2.66 (2.20, 3.21), P < 0.001]. An increase in atopic disease mirrored an increase in number of infectious outcomes and was statistically significant in the combined dataset (P < 0.001).

Conclusion

The associations between AD and AD plus another atopic disease with systemic infections suggest that an underlying immune defect may be contributing to microbial susceptibility. Further studies are warranted to understand the burden of infectious disease in this population.

Electronic supplementary material

The online version of this article (doi:10.1007/s13555-017-0172-7) contains supplementary material, which is available to authorized users.

Long-term effects of pneumococcal colonization during early childhood wheezing

BACKGROUND

Bacterial colonization during wheezing in early childhood has been associated with short-term relapses of wheezing, but no study has addressed the effects of Streptococcus pneumoniae colonization on long-term outcome of wheezing. The aim of the present study was therefore to evaluate whether pneumococcal (PNC) colonization during the first wheezing episode in early childhood is a determinant of asthma, atopy or lung function in the long term.

METHODS

In 1981-82 83 infants were hospitalized for first wheezing episode at <24 months of age. PNC colonization was defined as positive nasopharyngeal aspirate for S. pneumoniae either in culture or antigen detection on hospital admission. Atopy and repeated wheezing or asthma were diagnosed on all follow-up visits from infancy until the age of 28-31 years. Spirometry was conducted at the ages of 8-10, 18-20 and 28-31 years.

RESULTS

PNC colonization was found in 25/83 infants (30%) during hospitalization for wheezing in infancy. PNC colonization was not associated with later atopy, repeated wheezing, asthma or lung function at any time during the 30 year follow up.

CONCLUSION

PNC colonization during the first wheezing episode in early childhood is not a determinant of subsequent wheezing or later asthma, atopy or lung function in childhood, adolescence or adulthood.

Streptococcus pneumoniae colonisation in children and adolescents with asthma: impact of the heptavalent pneumococcal conjugate vaccine and evaluation of potential effect of thirteen-valent pneumococcal conjugate vaccine

Background

The main aim of this study was to evaluate Streptococcus pneumoniae carriage in a group of school-aged children and adolescents with asthma because these results might indicate the theoretical risk of invasive pneumococcal disease (IPD) of such patients and the potential protective efficacy of the 13-valent pneumococcal conjugate vaccine (PCV13).

Methods

Oropharyngeal samples were obtained from 423 children with documented asthma (300 males, 70.9 %), and tested for the autolysin-A-encoding (lytA) and the wzg (cpsA) gene of S. pneumoniae by means of real-time polymerase chain reaction.

Results

S. pneumoniae was identified in the swabs of 192 subjects (45.4 %): 48.4 % of whom were aged <10 years, 46.9 % aged 10–14 years, and 4.7 % aged ≥15 years (p < 0.001). Carriage was significantly less frequent among the children who had received recent antibiotic therapy (odds ratio [OR 0.41]; 95 % confidence interval [95 % CI] 0.22–0.76). Multivariate analyses showed no association between carriage and vaccination status, with ORs of 1.05 (95 % CI 0.70–1.58) for carriers of any pneumococcal serotype, 1.08 (95 % CI 0.72–1.62) for carriers of any of the serotypes included in 7-valent pneumococcal conjugate vaccine (PCV7), and 0.76 (95 % CI 0.45–1.28) for carriers of any of the six additional serotypes of PCV13. Serotypes 19 F, 4 and 9 V were the most frequently identified serotypes in vaccinated subjects.

Conclusions

These results showed that carriage of S. pneumoniae is relatively common in all school-aged children and adolescents with asthma, regardless of the severity of disease and the administration of PCV7 in the first years of life. This highlights the problem of the duration of the protection against colonisation provided by pneumococcal conjugate vaccine, and the importance of re-colonization by the same pneumococcal serotypes included in the previously used vaccine.

Nasal Levels of Antimicrobial Peptides in Allergic Asthma Patients and Healthy Controls: Differences and Effect of a Short 1,25(OH)2 Vitamin D3 Treatment

Background

Allergy is often accompanied by infections and lower levels of antimicrobial peptides (AMPs). Vitamin D has been shown to increase expression of selected AMPs. In this study we investigated whether antimicrobial peptide levels in nasal secretions of allergic asthma patients are lower than in healthy controls, and whether administration of the active form of vitamin D (1,25(OH)₂D3) affects these antimicrobial peptide levels.

Methods

The levels of antimicrobial peptides in nasal secretions were compared between 19 allergic asthma patients and 23 healthy controls. The effect of seven days daily oral treatment with 2 μg 1,25(OH)₂D3 on antimicrobial peptides in nasal secretions was assessed in a placebo-controlled cross-over clinical study.

Results

Levels of neutrophil α-defensins (human neutrophil peptides 1–3; HNP1-3) and lipocalin 2 (LCN2; also known as NGAL) were significantly lower in asthmatics, but no differences in LL-37 and SLPI were detected. Treatment with a short-term 1,25(OH)₂D3 caused a small increase in HNP1-3, but not when the asthma and control groups were analyzed separately. LL-37, LCN2 and SLPI did not change after treatment with 1,25(OH)₂D3.

Conclusion

Levels of the antimicrobial peptides HNP1-3 and LCN2 are lower in nasal secretions in asthmatics and are not substantially affected by a short-term treatment with active vitamin D.

Asthma-associated comorbidities in children with and without secondhand smoke exposure

BACKGROUND

Secondhand smoke (SHS) exposure is known to trigger asthma, but asthma disease severity and comorbidities in children exposed to SHS are not very well quantified.

OBJECTIVE

To identify comorbidities and understand health care usage in children with asthma exposed to SHS (cases) compared with children with asthma but without SHS exposure (controls).

METHODS

A retrospective nested matched case-and-control study was conducted with children 5 to 18 years old who were enrolled in the Pediatric Asthma Management Program. Pulmonary function testing (spirometry, methacholine challenges, and exhaled nitric oxide) and body mass index were reviewed. Influenza vaccination rates, oral steroid usage, emergency department visits, and hospitalizations were assessed. Network analysis of the 2 groups also was conducted to evaluate for any associations between the variables.

RESULTS

Cases had significantly higher body mass index percentiles (>75%, odds ratio [OR] 1.64, 95% confidence interval [CI] 1.22-2.2, P = .001). Cases were less likely to have had a methacholine challenge (OR 0.49, 95% CI 0.36-0.68, P < .001) and an exhaled nitric oxide (OR 0.6, 95% CI 0.37-0.97, P = .04) performed than controls. The ratio of forced expiration volume in 1 second to forced vital capacity and forced expiration volume in 1 second were lower in cases than in controls (P < .05). Cases were less likely to have received an influenza vaccination (OR 0.61, 95% CI 0.45-0.82, P = .001) than controls. Unsupervised multivariable network analysis suggested a lack of discrete and unique subgroups between cases and controls.

CONCLUSION

Children with asthma exposed to SHS are more likely to have comorbid conditions such as obesity, more severe asthma, and less health care usage than those not exposed to SHS. Smoking cessation interventions and addressing health disparities could be crucial in this vulnerable population.

Allergic Lung Inflammation Reduces Tissue Invasion and Enhances Survival from Pulmonary Pneumococcal Infection in Mice, Which Correlates with Increased Expression of Transforming Growth Factor β1 and SiglecF(low) Alveolar Macrophages

Asthma is generally thought to confer an increased risk for invasive pneumococcal disease (IPD) in humans. However, recent reports suggest that mortality rates from IPD are unaffected in patients with asthma and that chronic obstructive pulmonary disease (COPD), a condition similar to asthma, protects against the development of complicated pneumonia. To clarify the effects of asthma on the subsequent susceptibility to pneumococcal infection, ovalbumin (OVA)-induced allergic lung inflammation (ALI) was induced in mice followed by intranasal infection with A66.1 serotype 3 Streptococcus pneumoniae. Surprisingly, mice with ALI were significantly more resistant to lethal infection than non-ALI mice. The heightened resistance observed following ALI correlated with enhanced early clearance of pneumococci from the lung, decreased bacterial invasion from the airway into the lung tissue, a blunted inflammatory cytokine and neutrophil response to infection, and enhanced expression of transforming growth factor β1 (TGF-β1). Neutrophil depletion prior to infection had no effect on enhanced early bacterial clearance or resistance to IPD in mice with ALI. Although eosinophils recruited into the lung during ALI appeared to be capable of phagocytizing bacteria, neutralization of interleukin-5 (IL-5) to inhibit eosinophil recruitment likewise had no effect on early clearance or survival following infection. However, enhanced resistance was associated with an increase in levels of clodronate-sensitive, phagocytic SiglecF(low) alveolar macrophages within the airways following ALI. These findings suggest that, while the risk of developing IPD may actually be decreased in patients with acute asthma, additional clinical data are needed to better understand the risk of IPD in patients with different asthma phenotypes.

Atopy and cause-specific mortality

BACKGROUND

Atopy is the familial or personal propensity to develop immunoglobulin E (IgE) antibodies against common environmental allergens and is associated with high risk of allergic disease. It has been proposed that atopy may have effects on risk of cardiovascular disease and cancer.

OBJECTIVES

We investigated the association of atopy with all-cause and cause-specific mortality.

METHODS

We included a total of 14 849 individuals from five Danish population-based cohorts with measurements of atopy defined as serum-specific IgE positivity against inhalant allergens. Participants were followed by linkage to the Danish Registry of Causes of Death to obtain information on mortality status and cause of death (median follow-up time 11.3 years). The relative mortality risk was estimated by Cox regression and expressed as hazard ratios, HRs (95% confidence intervals, CIs).

RESULTS

A total of 1776 person died during follow-up. The mortality risk for atopics vs. non-atopics was: for all-cause mortality (HR = 1.03, 95% CI: 0.90, 1.17); neoplasms (HR = 0.86, 95% CI: 0.69, 1.06); endocrine, nutritional and metabolic disorders (HR = 1.48, 95% CI: 0.71, 3.08); mental and behavioural disorders (HR = 2.26, 95% CI: 1.18, 4.30); diseases of the nervous system (HR = 1.36, 95% CI: 0.65, 2.87); diseases of the circulatory system (HR = 1.00, 95% CI: 0.78, 1.29); diseases of the respiratory system (HR = 0.94, 95% CI: 0.55, 1.60); and diseases of the digestive system (HR = 1.75, 95% CI: 1.03, 2.98).

CONCLUSIONS & CLINICAL RELEVANCE

We found no statistically significant association between atopy and all-cause mortality. However, atopy was associated with a significantly higher risk of dying from mental and behavioural disorders and gastrointestinal diseases, particularly liver diseases, and a lower risk of dying from breast cancer, but these associations were not statistically significant when applying the Bonferroni adjusted significance level. Further studies are needed to confirm our findings.

The association between asthma and invasive pneumococcal disease: a nationwide study in Korea

The purpose of this study was to investigate the association between asthma and invasive pneumococcal disease (IPD) in Korea. A retrospective population-based cohort study was conducted using the Korean Health Insurance Review and Assessment database 2010-2011. The subjects included 935,106 (2010) and 952,295 (2011), of whom 398 (2010) and 428 (2011) patients with IPD were identified. There was significant difference in the prevalence of IPD in patients with and without asthma (0.07% vs. 0.02% in 2010 and 0.08% vs. 0.01% in 2011; P<0.001). After adjusting for age and gender, patients with asthma showed over a three-fold increased risk of IPD compared with patients without asthma (adjusted odds ratio [aOR] 3.90, 95% confidence interval [CI] 3.02-5.03 in 2010 / aOR, 5.44; 95% CI, 4.10-7.22 in 2011; P<0.001). These findings were also significant in children (aOR, 2.08; 95% CI, 1.25-3.45 in 2010; P=0.005 / aOR, 3.26; 95% CI, 1.74-6.11 in 2011; P<0.001). Although diabetes mellitus was also significantly associated with IPD, relatively low ORs compared with those of asthma were noted (aOR, 1.85; 95% CI, 1.35-2.54 in 2010 / aOR, 2.40; 95% CI, 1.78-3.24 in 2011; P<0.001). Both children and adults with asthma are at increased risk of developing IPD.

Clinical characteristics of adults with chronic rhinosinusitis and specific antibody deficiency

BACKGROUND

Specific antibody deficiency (SAD) involves a deficient response to a polysaccharide vaccine in the setting of normal immunoglobulin G (IgG) levels and chronic infections. Patients with chronic rhinosinusitis (CRS) are often evaluated for SAD. There are limited data that describe patients with CRS and SAD.

OBJECTIVE

The objective of this study was to better characterize the role of SAD in CRS.

METHODS

We reviewed electronic records of adults with CRS who were evaluated for immunodeficiency with quantitative Ig levels and pre- and postantibody titers to a pneumococcal polysaccharide vaccine (PPV).

RESULTS

Fourteen pneumococcal serotypes were determined in 239 subjects from 2002 to 2009. Of these subjects, 64 had adequate protective titers of 1.3 μg/mL or higher in 7 or more serotypes of the 14 serotypes checked; 56 (23%) had less than 7 protective titers post-PPV and were diagnosed with SAD; and 119 had an adequate response to the vaccine with 7 or more serotypes being higher than 1.3 μg/mL (>50% response) and were characterized as "responders." Subjects with SAD received more antibiotic courses relative to responders in the 2 years after immunization (3.19 ± 2.64 vs 2.19 ± 2.24, P < .05). Of 56 subjects with SAD, 10 (17.9%) received Ig replacement therapy. Subjects who received Ig had fewer numbers of protective pneumococcal titers post-PPV and had more pneumonia (40.0%) versus subjects with SAD who did not receive Ig (10.9%).

CONCLUSIONS

Of the 239 patients with CRS with normal IgG levels evaluated for immunodeficiency, 56 (23.4%) had SAD. A majority of patients with SAD may not need Ig replacement; however, a subset of patients with SAD benefit from Ig replacement.

Mast Cells in Lung Homeostasis: Beyond Type I Hypersensitivity

Lungs are indispensable organs for the respiratory process, and maintaining their homeostasis is essential for human health and survival. However, during the lifetime of an individual, the lungs suffer countless insults that put at risk their delicate organization and function. Many cells of the immune system participate to maintain this equilibrium and to keep functional lungs. Among these cells, mast cells have recently attracted attention because of their ability to rapidly secrete many chemical and biological mediators that modulate different processes like inflammation, angiogenesis, cell proliferation, etc. In this review, we focus on recent advances in the understanding of the role that mast cells play in lung protection during infections, and of the relation of mast cell responses to type I hypersensitivity-associated pathologies. Furthermore, we discuss the potential role of mast cells during wound healing in the lung and its association with lung cancer, and how mast cells could be exploited as therapeutic targets in some diseases

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.

What does tympanostomy tube placement in children teach us about the association between atopic conditions and otitis media?

Otitis media is the most common infection second only to viral upper respiratory infection in the outpatient setting. Tympanostomy tube insertion (TTI) is the most common ambulatory surgical procedure in the USA. While many risk factors for otitis media have been identified, atopic conditions have been underrecognized as risk factors for recurrent and persistent otitis media. Given that asthma and other atopic conditions are the most common chronic conditions during childhood, it is worth examining the association between atopic conditions and risk of otitis media, which can provide insight into how atopic conditions influence the risk of microbial infections. This paper focuses its discussion on otitis media; however, it is important that the association between atopic conditions and risk of otitis media be interpreted in the context of the association of atopic conditions with increased risks of various microbial infections.

Increased risk of refractory Mycoplasma pneumoniae pneumonia in children with atopic sensitization and asthma

Purpose

A nationwide outbreak of Mycoplasma pneumoniae pneumonia (MP) refractory to macrolide antibiotics occurred in Korea during 2011. Steroid therapy has been reported to be both efficacious and well tolerated in pediatric patients with refractory MP. We compared clinical features and laboratory characteristics between children with refractory MP requiring steroid treatment and those with macrolide-responsive MP and evaluated the risk factors associated with refractory MP.

Methods

We investigated 203 children who were admitted to our institution with MP from June to November 2011. Refractory MP was defined by persistent fever over 38.3℃ with progressive pulmonary consolidation or pleural effusion despite administration of appropriate macrolide antibiotics for 5 days or longer after admission. Steroid therapy was initiated on the fifth day after admission for refractory cases.

Results

There were 26 patients with refractory MP requiring steroid therapy. The mean duration of steroid therapy was 5.4 days and most of the patients were afebrile within 24 hours after initiation of steroid therapy. The prevalence of refractory MP was higher in patients with pleural effusion, lobar pneumonia affecting more than 2 lobes, higher levels of serum lactate dehydrogenase, increased oxygen requirements, and longer duration of hospitalization. Atopic sensitization and history of asthma were also associated with refractory MP after adjusting for age and gender.

Conclusion

Children with refractory MP had more severe pneumonia. Atopic sensitization and history of asthma may be risk factors for refractory MP requiring steroid therapy in Korean children.

Asthma and the immune response to MMR vaccine viruses in Somali immigrant children: a cross-sectional retrospective cohort study

Background:

According to the ‘hygiene hypothesis’, an increase in microbial exposure in childhood leads to a T-helper cell 1 (Th1) predominant immune response and protection against asthma and atopic conditions.

Aims:

To assess the prevalence of asthma and other atopic conditions in Somali immigrants and to determine the humoral immune response to the measles, mumps, and rubella (MMR) vaccine viruses in Somali immigrants with asthma.

Methods:

A retrospective cohort study was conducted in Olmsted County, Minnesota. Study subjects were Somali immigrants who were born and lived in Africa during childhood and immigrated to the USA. The subjects had participated in a previous MMR vaccine study. Asthma was ascertained using predetermined asthma criteria after a thorough medical record review. An atopic condition was determined from physician-diagnosed ICD codes. Virus-specific IgG levels in response to the MMR vaccine viruses were determined using an enzyme immunoassay.

Results:

Of the 62 eligible subjects, 33 (53%) were female and 29 (47%) were male; 10 (16%) had asthma and 22 (35%) had other atopic conditions. There was no difference in the rubella (p=0.150) and measles (p=0.715) virus-specific IgG levels between the subjects with and without asthma. Mumps virus-specific IgG antibody levels were lower in those with asthma than in those without asthma (mean±SE 2.08±0.28 vs. 3.06±0.14, p=0.005).

Conclusions:

Our study results may not support the hygiene hypothesis. In addition, the previously reported abnormal T-cell development in Caucasian children with atopy can be considered even in Somali immigrants.

Is asthma an infectious disease? New evidence

The pathogenetic mechanisms leading to asthma are likely to be diverse, influenced by multiple genetic polymorphisms as well as elements of the environment. Recent data on the microbiome of the airway have revealed intriguing differences between the number and diversity of microbial populations in healthy persons and asthmatics. There is convincing evidence that early viral infections, particularly with human rhinovirus and respiratory syncytial virus, are often associated with the development of chronic asthma and with exacerbations. Recent studies suggest that two unrelated types of atypical bacteria, Mycoplasma pneumoniae (Mpn) and Chlamydia pneumoniae, are present in the airways of a substantial proportion of the population, bringing up the possibility that the persistent presence of the organism may contribute to the asthmatic phenotype in a subset of patients. This review will examine the current data regarding a possible role for infection in chronic asthma with a particular focus on atypical bacterial infections.

Asthma and severity of 2009 novel H1N1 influenza: a population-based case-control study

BACKGROUND

Asthma has been shown to be associated with an increased risk of the 2009 novel H1N1 influenza (H1N1) infection among children. However, little is known about the role of asthma in severity of H1N1 infection.

OBJECTIVE

To determine the association between asthma and other atopic conditions and severity of H1N1 infection.

PATIENTS AND METHODS

We conducted a population-based case-control study. Cases were all Olmsted County, MN residents admitted to the hospital within a week of a positive test for H1N1. Controls who had a positive H1N1 but were not admitted to hospital were individually matched to cases with regard to birth day, gender, clinic registration date, diagnostic method, and calendar month of influenza testing. Asthma was ascertained using predetermined criteria. Data were fit to conditional logistic regression models.

RESULTS

There were 46 eligible individuals admitted to hospitals with H1N1 infection during the study period. Ninety-seven controls were individually matched to their corresponding cases. Among cases, 23 (50%) were male and 29 (63.0%) were Caucasians. The median age at hospitalization was 20.7 years. Twenty-five (54.4%) cases had asthma before the date of hospitalization, compared to 33 (34.0%) controls (matched OR: 2.31; 95% CI, 1.13-4.73; p = 0.02). This association approached statistical significance after adjusting for all pertinent covariates (adjusted matched OR: 2.55; 95% CI, 0.98-6.64; p = 0.055).

CONCLUSION

Asthma may be associated with severe H1N1 infection. In addition to timely influenza vaccination for asthmatics, consideration for prophylactic treatment for unimmunized asthmatics with significant exposure to influenza and immunized asthmatics with early flu-like symptoms should be given.

Asthma and risk of non-respiratory tract infection: a population-based case-control study

OBJECTIVES

Asthmatics have increased risks of airway-related infections. Little is known about whether this is true for non-airway-related serious infections such as Escherichia coli bloodstream infection (BSI). We assessed whether asthma is associated with a risk of developing community-acquired E coli BSI.

DESIGN

The study was designed as a population-based retrospective case-control study.

SETTING

This population-based study was conducted in Olmsted County, Minnesota.

PARTICIPANTS

The study included 259 all eligible community-acquired E coli BSI cases in Olmsted County, MN between 1998 and 2007 and 259 birthday-matched, gender-matched and residency-matched controls.

PRIMARY AND SECONDARY OUTCOME MEASURES

Only community-acquired E coli BSI cases as the primary outcome was included. Asthma status as an exposure was ascertained by predetermined criteria. An adjusted OR and 95% CI for the association between asthma and risk of community-acquired E coli BSI was calculated using conditional logistic regression.

RESULTS

Of 259 eligible cases, 179 (69%) were women and mean age was 61±22 years. Of the 259 cases 37 (14%) and 16 (6%) of 259 controls had a prior history of asthma (adjusted OR 2.74; 95% CI 1.11 to 6.76; p=0.029). The population attributable risk of asthma for community-acquired E coli BSI was 9%. Although not statistically significant, there was a borderline association between having a history of food allergy and increased risk of community-acquired E coli BSI (6% vs 2%; adjusted OR 3.51; 95% CI 0.94 to 13.11; p=0.062).

CONCLUSIONS

Based on the findings of the current population-based, case-control investigation, a history of asthma may be associated with risk of community-acquired E coli BSI. The impact of asthma on risk of microbial infections may go beyond airways.

Paediatric asthma and pneumococcal vaccination

Asthma is a clinical condition that has only recently been considered a risk factor for the development of pneumococcal infections. In the most recent guidelines concerning the use of pneumococcal vaccines, the Advisory Committee on Immunisation Practices recommends pneumococcal vaccination only when children with asthma aged <71 months are treated with high-dose corticosteroids, whereas the same Committee clearly indicates that asthma (without any definition of severity or treatment) is a reason for systematic pneumococcal vaccination in adults. It is also unclear which pneumococcal vaccine should be used and how to face the problem of booster doses. The main aim of this paper is to describe what is known about the real risk of pneumococcal infections in children with asthma, and discuss the unsolved problems regarding the paediatric use of pneumococcal vaccines. There are few published data regarding pneumococcal colonisation and the burden of pneumococcal disease in asthmatic children and adolescents, and none at all concerning the relationship between paediatric asthma and immune responses to pneumococcal vaccines. Further studies are therefore essential to assure that children and adolescents with asthma receive the best protection against pneumococcal diseases.

Atopic conditions other than asthma and risk of the 2009 novel H1N1 infection in children: a case-control study

A recent study showed an increased risk of 2009 novel H1N1 influenza (H1N1) infection among asthmatic children. Little is known whether this is true for other atopic conditions. This study was designed to determine the association between atopic dermatitis and/or allergic rhinitis and the risk of H1N1 infection among children. We conducted a case-control study in Olmsted County, MN. We randomly selected children ≤18 years of age with a positive test for H1N1. Controls were randomly selected from a pool of residents with negative H1N1 tests and were matched to cases with regard to birthday, gender, clinic registration date, diagnostic test, and month of influenza testing using frequency matching. We compared the frequency of atopic conditions other than asthma between cases and their matched controls. We enrolled 168 cases and 172 controls. Among cases, 91 (54.2%) were male patients, and 106 (63.1%) were white. The median age of cases was 6.3 years (interquartile range, 3.1-11.5). Among cases, 79 (47.0%) had atopic dermatitis and/or allergic rhinitis diagnosed before or after the index date, whereas 54 (31.4%) controls had such conditions (odds ratio [OR], 1.89; 95% CI, 1.15-3.12; p = 0.012, adjusting for asthma status, 2008-2009 seasonal influenza vaccine, time of illness at index date, and other comorbid conditions). History of receiving 2008-2009 seasonal influenza vaccine was associated with H1N1 infection (adjusted OR, 2.06; 95% CI, 1.32-3.28; p = 0.002). Our results suggest an association between H1N1 infection and atopic conditions other than asthma. The association between 2008-2009 seasonal influenza vaccinations and the risk of H1N1 requires further investigation.

Syndromic surveillance of surgical site infections--a case study in coronary artery bypass graft patients

OBJECTIVE

There is a wealth of data routinely collected and stored by healthcare facilities, which are not consistently exploited for surveillance of healthcare associated infections (HCAI). Syndromic surveillance has not yet been widely applied to HCAI. This study aimed to create syndromic surveillance for surgical site infections (SSI) following coronary artery bypass graft (CABG) procedures.

METHODS

A cohort of CABG patients from Imperial College Healthcare NHS Trust was investigated. Data from the local Patient Administration System, Laboratory Information Management System, radiology department, cardiac registry and Health Protection Agency SSI surveillance were linked. This data was explored for biological markers and proxies of infection, which were used to develop syndromic surveillance algorithms; sensitivity analysis was used to determine the best algorithms.

RESULTS

303 patients were included, with a SSI incidence of 6.6%. Wound culture requests, raised platelet and fibrinogen levels were all found to be good indicators of SSI. Two algorithms were generated, one to detect all SSI (sensitivity: 90%; specificity: 93.8%) and one to detect organ space infections specifically (sensitivity: 100%; specificity: 98.5%).

CONCLUSION

Data which is routinely collected and stored in healthcare facilities can be used for syndromic surveillance of SSI, allowing for an efficient surveillance system without the need for resource intensive data collection.

Respiratory infections in adults with atopic disease and IgE antibodies to common aeroallergens

Background

Atopic diseases, including allergic rhinitis, allergic dermatitis and asthma, are common diseases with a prevalence of 30–40% worldwide and are thus of great global public health importance. Allergic inflammation may influence the immunity against infections, so atopic individuals could be susceptible to respiratory infections. No previous population-based study has addressed the relation between atopy and respiratory infections in adulthood. We assessed the relation between atopic disease, specific IgE antibodies and the occurrence of upper and lower respiratory infections in the past 12 months among working-aged adults.

Methods and Findings

A population-based cross-sectional study of 1008 atopic and non-atopic adults 21–63 years old was conducted. Information on atopic diseases, allergy tests and respiratory infections was collected by a questionnaire. Specific IgE antibodies to common aeroallergens were measured in serum. Adults with atopic disease had a significantly increased risk of lower respiratory tract infections (LRTI; including acute bronchitis and pneumonia) with an adjusted risk ratio (RR) 2.24 (95% confidence interval [CI] 1.43, 3.52) and upper respiratory tract infections (URTI; including common cold, sinusitis, tonsillitis, and otitis media) with an adjusted RR 1.55 (1.14, 2.10). The risk of LRTIs increased with increasing level of specific IgE (linear trend P = 0.059).

Conclusions

This study provides new evidence that working-aged adults with atopic disease experience significantly more LRTIs and URTIs than non-atopics. The occurrence of respiratory infections increased with increasing levels of specific IgE antibodies to common aeroallergens, showing a dose-response pattern with LRTIs. From the clinical point of view it is important to recognize that those with atopies are a risk group for respiratory infections, including more severe LRTIs.

Budesonide suppresses pulmonary antibacterial host defense by down-regulating cathelicidin-related antimicrobial peptide in allergic inflammation mice and in lung epithelial cells

BACKGROUND

Glucocorticoids are widely regarded as the most effective treatment for asthma. However, the direct impact of glucocorticoids on the innate immune system and antibacterial host defense during asthma remain unclear. Understanding the mechanisms underlying this process is critical to the clinical application of glucocorticoids for asthma therapy. After sensitization and challenge with ovalbumin (OVA), BALB/c mice were treated with inhaled budesonide and infected with Pseudomonas aeruginosa (P. aeruginosa). The number of viable bacteria in enflamed lungs was evaluated, and levels of interleukin-4 (IL-4) and interferon-γ (IFN-γ) in serum were measured. A lung epithelial cell line was pretreated with budesonide. Levels of cathelicidin-related antimicrobial peptide (CRAMP) were measured by immunohistochemistry and western blot analysis. Intracellular bacteria were observed in lung epithelial cells.

RESULTS

Inhaled budesonide enhanced lung infection in allergic mice exposed to P. aeruginosa and increased the number of viable bacteria in lung tissue. Higher levels of IL-4 and lower levels of IFN-γ were observed in the serum. Budesonide decreased the expression of CRAMP, increased the number of internalized P. aeruginosa in OVA-challenged mice and in lung epithelial cell lines. These data indicate that inhaled budesonide can suppress pulmonary antibacterial host defense by down-regulating CRAMP in allergic inflammation mice and in cells in vitro.

CONCLUSIONS

Inhaled budesonide suppressed pulmonary antibacterial host defense in an asthmatic mouse model and in lung epithelium cells in vitro. This effect was dependent on the down-regulation of CRAMP.

The effect of pneumococcal polysaccharide vaccine in a mouse model of allergic rhinitis

OBJECTIVES

This study aimed to determine if pneumococcal polysaccharide vaccine (PPV) could suppress allergic inflammation in an allergic rhinitis mouse model and to explore whether differences exist regarding the effect of PPV according to timing of administration.

STUDY DESIGN

In vivo study using an animal model.

SETTING

Catholic Research Institutes of Medical Science.

SUBJECTS AND METHODS

BALB/c mice were divided into control, Der f, Pre-S, and Post-S groups. The allergen was Dermatophagoides farinae (Der f). Pneumococcal polysaccharide vaccine was administered before (Pre-S) or after (Post-S) sensitization. Allergic symptoms and eosinophils in nasal mucosa, interferon-γ, interleukin (IL)-13, and IL-10 in nasal lavage fluid and serum Der f-specific IgE were measured. T-bet, GATA-3, and Foxp3 mRNA in spleen were determined by real-time polymerase chain reaction. Flow cytometry of CD4(+)CD25(+)Foxp3(+) T cells in spleen was analyzed.

RESULTS

In the Pre-S group, symptom score, serum Der f-specific IgE, eosinophils, IL-13, and GATA-3 mRNA were decreased (P < .05), and IL-10, Foxp3 mRNA, and CD4(+)CD25(+)Foxp3(+) T cells were increased compared with those in Der f group (P < .05). In the Post-S group, symptom score, serum Der f-specific IgE, and GATA-3 mRNA were decreased (P < .05), and Foxp3 mRNA and CD4(+)CD25(+)Foxp3(+) T cells were increased compared with those in the Der f group (P < .05).

CONCLUSION

These results suggest that PPV administered before or after sensitization suppresses Th2 response and enhanced induction of regulatory T cells in an allergic rhinitis model. In addition, there was no significant difference between the degrees of effects in these 2 conditions. In the future, we can consider PPV to be a preventative agent for allergic rhinitis.

Deficient antiviral immune responses in childhood: distinct roles of atopy and asthma

BACKGROUND

Impaired immune response to viral infections in atopic asthmatic patients has been recently reported and debated. Whether this condition is present in childhood and whether it is affected by atopy per se deserves further investigation.

OBJECTIVE

We sought to investigate airway interferon production in response to rhinovirus infection in children who are asthmatic, atopic, or both and its correlation with the airway inflammatory profile.

METHODS

Bronchial biopsy specimens and epithelial cells were obtained from 47 children (mean age, 5 ± 0.5 years) undergoing bronchoscopy. The study population included asthmatic children who were either atopic or nonatopic, atopic children without asthma, and children without atopy or asthma. Rhinovirus type 16 induction of IFN-λ and IFN-β mRNA and protein levels was assessed in bronchial epithelial cell cultures. The immunoinflammatory profile was evaluated by means of immunohistochemistry in bronchial biopsy specimens.

RESULTS

Rhinovirus type 16-induced interferon production was significantly reduced in atopic asthmatic, nonatopic asthmatic, and atopic nonasthmatic children compared with that seen in nonatopic nonasthmatic children (all P < .05). Increased rhinovirus viral RNA levels paralleled this deficient interferon induction. Additionally, IFN-λ and IFN-β induction correlated inversely with the airway T(H)2 immunopathologic profile (eosinophilia and IL-4 positivity: P < .05 and r = -0.38 and P < .05 and r = -0.58, respectively) and with epithelial damage (P < .05 and r = -0.55). Furthermore, total serum IgE levels correlated negatively with rhinovirus-induced IFN-λ mRNA levels (P < .05 and r = -0.41) and positively with rhinovirus viral RNA levels (P < .05 and r = 0.44).

CONCLUSIONS

Deficient interferon responses to rhinovirus infection are present in childhood in asthmatic subjects irrespective of their atopic status and in atopic patients without asthma. These findings suggest that deficient immune responses to viral infections are not limited to patients with atopic asthma but are present in those with other T(H)2-oriented conditions.

Response to infections in patients with asthma and atopic disease: an epiphenomenon or reflection of host susceptibility?

Associations between respiratory tract infections and asthma inception and exacerbations are well established. Infant respiratory syncytial virus and rhinovirus infections are known to be associated with an increased risk of asthma development, and among children with prevalent asthma, 85% of asthma exacerbations are associated with viral infections. However, the exact nature of this relationship remains unclear. Is the increase in severity of infections an epiphenomenon, meaning respiratory tract infections just appear to be more severe in patients with underlying respiratory disease, or instead a reflection of altered host susceptibility among persons with asthma and atopic disease? The main focus of this review is to summarize the available levels of evidence supporting or refuting the notion that patients with asthma or atopic disease have an altered susceptibility to selected pathogens, as well as discussing the biological mechanism or mechanisms that might explain such associations. Finally, we will outline areas in need of further research because understanding the relationships between infections and asthma has important implications for asthma prevention and treatment, including potential new pathways that might target the host immune response to select pathogens.

Atopic asthmatic patients have reduced airway inflammatory cell recruitment after inhaled endotoxin challenge compared with healthy volunteers

BACKGROUND

Atopic asthmatic patients are reported to be more sensitive to the effects of environmental endotoxin (LPS) than healthy volunteers (HVs). It is unknown whether this sensitivity is due to dysregulated inflammatory responses after LPS exposure in atopic asthmatic patients.

OBJECTIVE

We sought to test the hypothesis that atopic asthmatic patients respond differentially to inhaled LPS challenge compared with HVs.

METHODS

Thirteen allergic asthmatic (AA) patients and 18 nonallergic nonasthmatic subjects (healthy volunteers [HVs]) underwent an inhalation challenge to 20,000 endotoxin units of Clinical Center Reference Endotoxin (LPS). Induced sputum and peripheral blood were obtained at baseline and 6 hours after inhaled LPS challenge. Sputum and blood samples were assayed for changes in inflammatory cell numbers and cytokine and cell-surface marker levels on monocytes and macrophages.

RESULTS

The percentage of neutrophils in sputum (%PMN) in induced sputum similarly and significantly increased in both HVs and AA patients after inhaled LPS challenge. However, the absolute numbers of leukocytes and PMNs recruited to the airways were significantly lower in AA patients compared with those seen in HVs with inhaled LPS challenge. Sputum levels of IL-6 and TNF-α were significantly increased in both cohorts, but levels of IL-1β and IL-18 were only significantly increased in the HV group. Cell-surface expression of Toll-like receptors 4 and 2 were significantly enhanced only in the HV group.

CONCLUSIONS

The airway inflammatory response to inhaled LPS challenge is blunted in AA patients compared with that seen in HVs and accompanied by reductions in airway neutrophilia and inflammasome-dependent cytokine production. These factors might contribute to increased susceptibility to airway microbial infection or colonization in AA patients.

Streptococcus pyogenes upper respiratory infection and atopic conditions other than asthma: a retrospective cohort study

BACKGROUND

Patients with asthma have an increased risk of Streptococcus pyogenes infection compared with those without asthma. It is unknown whether this is true for children with other atopic conditions such as atopic dermatitis or allergic rhinitis.

AIMS

To determine the risk of developing S. pyogenes infections of the upper respiratory tract in children and adolescents with atopic dermatitis and/or allergic rhinitis.

METHODS

We conducted a retrospective cohort study that followed a convenience sample of 340 healthy children. Atopic dermatitis or eczema and allergic rhinitis or hay fever were determined based on a physician diagnosis documented in medical records. All laboratory test results of cultures, rapid antigen detection, and polymerase chain reaction tests for S. pyogenes infections during the first 18 years of life were collected to compare the incidence of S. pyogenes infections between children with and without a physician diagnosis of atopic conditions. A Poisson regression was fit to determine the association between asthma and S. pyogenes infections, controlling for other covariates including asthma.

RESULTS

Of the 340 subjects, 327 were eligible for the study. Of these 327 subjects, 143 (44%) had atopic conditions other than asthma. The incidence of S. pyogenes infections in children with atopic conditions other than asthma and those without atopic conditions was 0.24 per person-year and 0.18 per person-year, respectively. The adjusted risk ratios for allergic rhinitis and atopic dermatitis were 1.36 (95% CI 1.07 to 1.66, p=0.011) and 1.30 (95% CI 0.98 to 1.71, p=0.06), respectively, controlling for asthma and other covariates.

CONCLUSIONS

In addition to asthma, allergic rhinitis but not atopic dermatitis is associated with an increased risk of S. pyogenes upper respiratory tract infections.

Increased Prevalence of H1N1-Induced Severe Lower Respiratory Tract Diseases in Children With Atopic Sensitization

Purpose

Viral infection is the most common aggravating factor for childhood asthma. Asthma may be a risk factor for severe respiratory symptoms in children with lower respiratory tract infections of viral etiology. Influenza A infection enhances Th2-polarization to house dust mites during the acute phase and leads to lung dysfunction in a mouse model. However, there are no data on the relationship between atopic sensitization and H1N1 (Influenza A) infection in humans. To investigate whether atopic sensitization is associated with the severity of H1N1 pneumonia, we compared clinical features and the atopic sensitization rate between children with and without H1N1 infection.

Methods

Using reverse transcription-polymerase chain reactions, we investigated H1N1 virus infection in 214 children who were hospitalized with high fever and respiratory symptoms from September 2009 to February 2010. We also performed immunoassays for total and specific IgEs to six common aeroallergens. Atopy was defined as positivity for more than one specific IgE. The clinical severity of pneumonia was evaluated based on intensive care unit admission, oxygen therapy, steroid therapy, and atelectasis.

Results

There were 70 H1N1-positive children, 42.9% of whom had pneumonia. Children with H1N1 infection were older and had a higher prevalence of atopic sensitization and pneumonia compared with H1N1-negative children. The rate of atelectasis was higher in children with H1N1 pneumonia than in children with non-H1N1 pneumonia. Among children with H1N1 viral infection, those with atopic sensitization had a higher prevalence of intensive care unit admission and oxygen therapy, and a longer duration of hospitalization than non-atopic children. There were no differences between atopic and non-atopic children without H1N1 viral infection.

Conclusions

The prevalence of H1N1-induced severe lower respiratory tract diseases is higher in children with atopic sensitization.

Influence of asthma epidemiology on the risk for other diseases

Asthma is a multifactorial chronic disease affecting a significant proportion of people in the United States and worldwide. Numerous laboratory and epidemiological studies have attempted to understand the etiology and underlying mechanisms of asthma and to identify effective therapies. However, the impact of asthma on the risk for other diseases has drawn little attention. This paper discusses the potential effects of asthma as a risk factor for other diseases, explores the potential mechanisms, and reviews the implications of the findings to clinical practice, public health, and research.

Assessment of the association between atopic conditions and tympanostomy tube placement in children

This study assesses the relationship between otitis media and atopic conditions in children by comparing the incidence of tympanostomy tube placement between children with and without atopic conditions: asthma, allergic rhinitis, and atopic dermatitis. Study subjects were a cohort of 323 healthy children who participated in a study of vaccine response. All episodes of tympanostomy tube placement and physician diagnoses of allergic rhinitis and atopic dermatitis were collected through comprehensive medical record review. Asthma status was ascertained through application of established criteria. We compared incidence rates of tympanostomy tube placement between children with and without atopic conditions. We fitted data to a Poisson regression model to calculate relative risk ratios (RRs) and their corresponding 95% confidence intervals (95% CI). Three subjects were excluded who did not have parental authorization for using records for research. Of the remaining 320 subjects, 170 (53%) were male subjects, 268 (94%) were white, 124 (39%) were asthmatic patients, and 20 (6%) had tympanostomy tube placement. Children with asthma before the index date of tympanostomy tube placement were more likely to have tympanostomy tube placement compared with those without asthma (RR, 19.33; 95% CI, 11.41; 32.75; p < 0.001). We found a similar association between asthma ever (before or after index date) and the incidence of tympanostomy tube placement (RR, 1.53; 95% CI, 0.93-2.53; p = 0.095). This was true for children with allergic rhinitis compared with those without allergic rhinitis (RR, 1.70; 95% CI, 1.01-2.86; p = 0.007). Atopic dermatitis was not associated with the incidence of tympanostomy tube placement. Asthma or allergic rhinitis may be unrecognized risk factors for recurrent or persistent otitis media. However, given the small sample size of the study, a cohort study with a larger sample size is necessary.

Pneumococcal infections: association with asthma and COPD

Pneumococci are responsible for lower respiratory tract infections (bronchitis and pneumonia) and invasive infections (bacteremia and meningitis). Pneumococcal vaccination is recommended for adults at high risk of pneumococcal infection. Asthma is not currently considered as an indication for pneumococcal vaccination and this vaccination is indicated only in case of respiratory insufficiency. Indeed, asthma is not usually considered as a risk factor for pneumococcal infection and pneumococcal polysaccharide vaccine does not decrease mortality in patients presenting with COPD. According to several recent epidemiological studies, asthma is associated with a doubled risk of pneumonia and invasive infections. This epidemiological association is supported by biological data suggesting increased susceptibility to pneumococcal infection in asthmatic patients. Pneumococci are responsible for 10 to 15% of acute exacerbations and onset of often-severe pneumonia in patients presenting with COPD. The recent availability of pneumococcal conjugate vaccines could be interesting for these patients, but their clinical and cost effectiveness will have to be demonstrated before they can be recommended for these conditions.

Advances in basic and clinical immunology in 2010

Reports in basic and clinical immunology in 2010 reflected the use of state-of-the-art genetic and immunologic tools to characterize the pathogenesis of immunologic diseases and the development of novel therapies directed to these conditions. B-cell biology has been explained in greater detail, significantly with lessons from the genetic defects found in the humoral immunodeficiencies. Therapeutic mAbs are given for an increasing number of indications, such as anti-CD20 antibodies or rituximab, which was initially developed for non-Hodgkin lymphomas and is currently used in diverse autoimmune and inflammatory disorders. The report of an infant with severe combined immunodeficiency (SCID) in Massachusetts detected by means of newborn screening and successfully treated with hematopoietic stem cell transplantation validated recent efforts toward newborn screening for SCID. Improvement of survival outcomes for patients with primary immunodeficiencies treated with hematopoietic stem cell transplantation was demonstrated in a large European cohort, with significant appreciation of the type of donor graft, particularly the use of HLA-matched unrelated donors for patients with non-SCID. Progress in cellular mechanisms of drug hypersensitivity included the characterization of nitroso-modified drug metabolites as potent T-cell activators and the identification of the relocation of plasmacytoid dendritic cells from blood to skin as a potential risk factor for reactivation of viral disease.