Pre-existing Asthma Research Articles

Asthma exacerbations among asthmatic children receiving live attenuated versus inactivated influenza vaccines

ObjectiveTo investigate whether there is a difference in the risk of asthma exacerbations between children with pre-existing asthma who receive live attenuated influenza vaccine (LAIV) compared with inactivated influenza vaccine (IIV). Material and methodsWe identified IIV and LAIV immunizations occurring between July 1, 2007 and March 31, 2014 among Kaiser Permanente Northern California members aged 2 to <18years with a history of asthma, and subsequent asthma exacerbations seen in the inpatient or Emergency Department (ED) setting. We calculated the ratio of the odds (OR) of an exacerbation being in the risk interval (1–14days) versus the comparison interval (29–42days) following immunization, separately for LAIV and IIV, and then examined whether the OR differed between children receiving LAIV and those receiving IIV (“difference-in-differences”). ResultsAmong 387,633 immunizations, 85% were IIV and 15% were LAIV. Children getting LAIV vs. IIV were less likely to have “current or recent, persistent” asthma (25% vs. 47%), and more likely to have “remote history” of asthma (47% vs. 25%). Among IIV-vaccinated asthmatic children, the OR of an inpatient/ED asthma exacerbation was 0.97 (95% CI: 0.82–1.15). Among LAIV-vaccinated asthmatic children the OR was 0.38 (95% CI: 0.17–0.90). In the difference-in-differences analysis, the odds of asthma exacerbation following LAIV were less than IIV (Ratio of ORs: 0.40, CI: 0.17–0.95, p value: 0.04). ConclusionAmong children ≥2years old with asthma, we found no increased risk of asthma exacerbation following LAIV or IIV, and a decreased risk following LAIV compared to IIV.

Opportunities and obstacles in translating evidence to policy in occupational asthma

PurposeOccupational asthma (OA), a common respiratory disorder in Western countries, is caused by exposures at the workplace. It is part of a broader definition of work-related asthma (WRA) that also includes pre-existing asthma aggravated by substances present in the workplace environment, and it is potentially preventable. The purpose of this paper is to illustrate preventive measures for occupational asthma by case studies. MethodsIn three case studies we discuss preventive measures that have been associated with reductions in incidence of occupational asthma from natural rubber latex and from diisocyanates as supported by published literature. We also discuss challenges in relation to asthma from cleaning products in healthcare work. Results and conclusionsSeveral preventive measures have been associated with reduction in incidence of occupational asthma from natural rubber latex and from diisocyanates, and may provide lessons for prevention of other causes of occupational asthma. Cleaning products remain an unresolved problem at present with respect to asthma risks but potential measures include the use of safer products and safer applications such as avoidance of spray products, use of occupational hygiene methods such as improving local ventilation, and when appropriate, the use of personal protective devices.

Oral administration of Lactobacillus paracasei L9 attenuates PM2.5-induced enhancement of airway hyperresponsiveness and allergic airway response in murine model of asthma.

This study investigated allergy immunotherapy potential of Lactobacillus paracasei L9 to prevent or mitigate the particulate matter 2.5 (PM2.5) enhanced pre-existing asthma in mice. Firstly, we used a mouse model of asthma (a 21-day ovalbumin (OVA) sensitization and challenge model) followed by PM2.5 exposure twice on the same day of the last challenge. PM2.5 was collected from the urban area of Beijing and underwent analysis for metals and polycyclic aromatic hydrocarbon contents. The results showed that PM2.5 exposure enhanced airway hyper-responsiveness (AHR) and lead to a mixed Th2/ IL-17 response in asthmatic mice. Secondly, the PM2.5 exposed asthmatic mice were orally administered with L9 (4×107, 4×109 CFU/mouse, day) from the day of first sensitization to the endpoint, for 20 days, to investigate the potential mitigative effect of L9 on asthma. The results showed that L9 ameliorated PM2.5 exposure enhanced AHR with an approximate 50% decrease in total airway resistance response to methacholine (48 mg/ml). L9 also prevented the exacerbated eosinophil and neutrophil infiltration in bronchoalveolar lavage fluid (BALF), and decreased the serum level of total IgE and OVA-specific IgG1 by 0.44-fold and 0.3-fold, respectively. Additionally, cytokine production showed that L9 significantly decreased T-helper cell type 2 (Th2)–related cytokines (IL-4, -5, -13) and elevated levels of Th1 related IFN-γ in BALF. L9 also reduced the level of IL-17A and increased the level of TGF-β. Taken together, these results indicate that L9 may exert the anti-allergic benefit, possibly through rebalancing Th1/Th2 immune response and modulating IL-17 pro-inflammatory immune response. Thus, L9 is a promising candidate for preventing PM exposure enhanced pre-existing asthma.

Ambient air pollution and adverse birth outcomes: Differences by maternal comorbidities

BackgroundPrenatal exposure to ambient air pollution has been associated with adverse birth outcomes, but the potential modifying effect of maternal comorbidities remains understudied. Our objective was to investigate whether associations between prenatal air pollution exposures and birth outcomes differ by maternal comorbidities. MethodsA total of 818,400 singleton live births were identified in the province of Ontario, Canada from 2005 to 2012. We assigned exposures to fine particulate matter (PM2.5), nitrogen dioxide (NO2) and ozone (O3) to maternal residences during pregnancy. We evaluated potential effect modification by maternal comorbidities (i.e. asthma, hypertension, pre-existing diabetes mellitus, heart disease, gestational diabetes and preeclampsia) on the associations between prenatal air pollution and preterm birth, term low birth weight and small for gestational age. ResultsInterquartile range (IQR) increases in PM2.5 (2μg/m3), NO2 (9ppb) and O3 (5ppb) over the entire pregnancy were associated with a 4% (95% CI: 2.4–5.6%), 8.4% (95% CI: 5.5–10.3%) and 2% (95% CI: 0.5–4.1%) increase in the odds of preterm birth, respectively. Increases of 10.6% (95% CI: 0.2–2.1%) and 23.8% (95% CI: 5.5–44.8%) in the odds of preterm birth were observed among women with pre-existing diabetes while the increases were of 3.8% (95% CI: 2.2–5.4%) and 6.5% (95% CI: 3.7–8.4%) among women without this condition for pregnancy exposure to PM2.5 and NO2, respectively (Pint<0.01). The increase in the odds of preterm birth for exposure to PM2.5 during pregnancy was higher among women with preeclampsia (8.3%, 95% CI: 0.8–16.4%) than among women without (3.6%, 95% CI: 1.8–5.3%) (Pint=0.04). A stronger increase in the odds of preterm birth was found for exposure to O3 during pregnancy among asthmatic women (12.0%, 95% CI: 3.5–21.1%) compared to non-asthmatic women (2.0%, 95% CI: 0.1–3.5%) (Pint<0.01). We did not find statistically significant effect modification for the other outcomes investigated. ConclusionsFindings of this study suggest that associations of ambient air pollution with preterm birth are stronger among women with pre-existing diabetes, asthma, and preeclampsia.

Pre-existing Pulmonary Diseases and Survival in Patients With Stage-dependent Lung Adenocarcinoma: A STROBE-compliant Article.

Asthma, chronic obstructive pulmonary disease (COPD), and pulmonary tuberculosis (TB) are common lung diseases associated with lung cancer mortality. This study evaluated sex disparities in pre-existing pulmonary diseases and stage-dependent lung adenocarcinoma survival.Patients newly diagnosed with lung adenocarcinoma between 2003 and 2008 were identified using the National Health Insurance Research Database and Cancer Registry. Cases with lung adenocarcinoma were followed until the end of 2010. Survival curves were estimated by the Kaplan-Meier method. Cox proportional-hazard regression was used to calculate the hazard ratio (HR) of pre-existing asthma, COPD, and/or TB, and to estimate all-cause mortality risk in patients with different stages of lung adenocarcinoma.A total of 14,518 cases were identified with lung adenocarcinoma. Specifically, among men, the HRs for TB were 1.69 (95% confidence interval [CI], 1.10-2.58), 1.48 (95% CI, 1.14-1.93), and 1.27 (95% CI, 1.08-1.49) for individuals with stage I + II, III, and IV diseases, respectively. The HRs for asthma were 1.41 (95% CI, 1.00-1.99) in women with stage I + II and 1.14 (95% CI, 1.04-1.26) in men with stage IV disease. For pulmonary disease combinations in men, the HRs were 1.45 (95% CI, 1.12-1.89) for asthma + COPD + TB, 1.35 (95% CI, 1.12-1.63) for COPD + TB, 1.28 (95% CI, 1.01-1.63) for TB, and 1.15 (95%CI, 1.04-1.27) for asthma + COPD, respectively. For women with stage I + II disease, the HR was 6.94 (95% CI, 2.72-17.71) for asthma + COPD + TB.Coexistence of pre-existing pulmonary diseases increased mortality risk in men with adenocarcinoma. TB is at elevated risk of mortality among men with different stages of adenocarcinoma. Asthmatic women with early-stage adenocarcinoma had increased risk of mortality.

Persistent airway inflammation and high exacerbation rate in asthma that starts at menopause

Asthma that begins around the time of menopause is frequently characterised by marked clinical severity and poor response to treatment. We sought to assess the clinical characteristics, bronchial responsiveness, perception of induced bronchoconstriction and airway inflammation in women with menopausal asthma, as compared to women of a similar age with pre-existing asthma. Nine women with pre-existing asthma were selected for clinical severity (symptoms, lung function and medication requirements) similar to that in 11 women with menopausal asthma. Anti-asthmatic treatment in all of the study patients included high dose inhaled (with or without oral) corticosteroids. The women with menopausal asthma demonstrated less atopy, more chronic recurrent sinusitis, similar airway responsiveness, and similar perception of induced bronchoconstriction, but a significantly higher sputum eosinophil count (19.5 +/- 10.8 versus 3.3 +/- 4.3%; p < 0.001) and a higher severe exacerbation rate during the 1-year follow-up period (5.09 +/- 4.85 versus 0.78 +/- 0.97; p < 0.05). Sputum eosinophil count and severe asthma exacerbation rate correlated well in both groups considered as a whole (r = 0.65; p < 0.005). The eosinophilic airway inflammation present in women with menopausal asthma is poorly responsive to anti-inflammatory treatment with corticosteroids and predisposes to frequent severe exacerbations. Airway inflammation should be monitored in women with menopausal asthma.

Enterovirus 68 Infection–Association with Asthma

A previously sporadic virus called enterovirus 68 (EV-D68) appears to have been associated with asthma-like illness with a predisposition for asthmatics after an outbreak that occurred in North America in 2014. Clinicians should be aware of the clinical associations with EV-D68 particularly its predilection with pre-existing asthma or asthma-like illness as well as the potential association with acute flaccid myelitis. Further elucidation and development of diagnostic and treatments modalities are warranted to better understand and limit the potential public health impact of future outbreaks of EV-D68 infection.

English

Pregnancy may be complicated by new-onset or preexisting asthma and allergic rhinitis.This article reviews the recognition and management of asthma and allergic rhinitis during pregnancy, paying close attention to the general principles of allergy and use of asthma medication during pregnancy. Both allergic rhinitis and asthma can adversely affect both maternal quality of life and, in the case of maternal asthma, perinatal outcomes. Optimal management is thus important for both mother and baby. This article reviews the safety of asthma and allergy medications commonly used during pregnancy.

The Relationship between Depression and Asthma: A Meta-Analysis of Prospective Studies.

BackgroundPrevious studies have suggested that asthmatic patients often have comorbid depression; however, temporal associations remain unclear.ObjectivesTo determine whether depression predicts asthma and, conversely, whether asthma predicts depression.MethodsA literature search was conducted without language restrictions using Pubmed, Embase, Cochrane and PsycINFO for studies published before January, 2015. Papers referenced by the obtained articles were also reviewed. Only comparative prospective studies with reported risk estimates of the association between depression and asthma were included. In order to investigate whether one of these conditions was predictive of the other, studies were excluded if enrolled participants had pre-existing depression or asthma. A random-effects model was used to calculate the pooled risk estimates for two outcomes: depression predicting asthma and asthma predicting depression.ResultsSeven citations, derived from 8 cohort studies, met our inclusion criteria. Of these, six studies reported that depression predicted incident adult-onset asthma, including 83684 participants and 2334 incident cases followed for 8 to 20 years. Conversely, two studies reported that asthma predicted incident depression. These studies involved 25566 participants and 2655 incident cases followed for 10 and 20 years, respectively. The pooled adjusted relative risks (RRs) of acquiring asthma associated with baseline depression was 1.43 (95% CI, 1.28–1.61) (P<0.001). The adjusted RRs for acquiring depression associated with baseline asthma was 1.23 (95% CI, 0.72–2.10) (P = 0.45).ConclusionsDepression was associated with a 43% increased risk of developing adult-onset asthma. However, asthma did not increase the risk of depression based on limited studies. Further prospective studies ascertaining the true association between asthma and subsequent risk of depression are warranted.

The Impact of Coexisting Asthma, Chronic Obstructive Pulmonary Disease and Tuberculosis on Survival in Patients with Lung Squamous Cell Carcinoma.

BackgroundPulmonary diseases [asthma, chronic obstructive pulmonary disease (COPD), and tuberculosis (TB)] are associated with lung cancer mortality. However, the relationship between coexisting pulmonary diseases and survival in patients with lung squamous cell carcinoma (SqCC) has not been well defined.MethodsPatients newly diagnosed with SqCC between 2003 and 2008 were identified by linking the National Health Insurance Research Database and Taiwan Cancer Registry Database. Cases with SqCC were followed up until death, loss to follow-up, or study end in 2010. Information on health status, date of death and the main causes of death was ascertained from the National Death Registry Database. Cox proportional hazard regression was used to calculate the hazard ratio (HR) of coexisting asthma, COPD and/or TB.ResultsDuring the study period, a total of 5406 cases with SqCC were enrolled. For all cause-mortality, HRs were 1.08 [95% confidence interval (CI), 0.99–1.18], 1.04 (95% CI, 0.97–1.12), and 1.14 (95% CI, 1.00–1.31) for individuals with asthma, COPD, and TB, respectively. Specifically, among men with coexisting pulmonary diseases, the HRs were 1.56 (95% CI, 1.23–1.97) and 1.11 (95% CI, 1.00–1.24) for individuals with asthma+COPD+TB and asthma+COPD, respectively. Among male patients with stage III SqCC, HRs were 3.41 (95%CI, 1.27–9.17) and 1.65 (95%CI, 1.10–2.47) for individuals with asthma+TB and asthma+COPD+TB, respectively. Among male patients with stage IV SqCC, HRs were 1.40 (95%CI, 1.00–1.97) and 1.25 (95%CI, 1.03–1.52) for individuals with asthma+ COPD+TB and asthma. Among female patients with stage I and II, HR was 0.19 (95%CI, 005–0.77) for individuals with asthma.ConclusionsCoexisting pulmonary diseases increased the risk of mortality from SqCC in male patients. For female patients with early stage SqCC, pre-existing asthma decreased mortality. These patients deserve greater attention while undergoing cancer treatment.

An official American Thoracic Society Workshop Report: presentations and discussion of the fifth Jack Pepys Workshop on Asthma in the Workplace. Comparisons between asthma in the workplace and non-work-related asthma.

The fifth Jack Pepys Workshop on Asthma in the Workplace focused on the similarities and differences of work-related asthma (WRA) and non-work-related asthma (non-WRA). WRA includes occupational asthma (OA) and work-exacerbated asthma (WEA). There are few biological differences in the mechanisms of sensitization to environmental and occupational allergens. Non-WRA and OA, when due to high-molecular-weight agents, are both IgE mediated; it is uncertain whether OA due to low-molecular-weight agents is also IgE mediated. Risk factors for OA include female sex, a history of upper airway symptoms, and a history of bronchial hyperresponsiveness. Atopy is a risk factor for OA due to high-molecular-weight agents, and exposure to cleaning agents is a risk factor for both OA and non-WRA. WEA is important among workers with preexisting asthma and may overlap with irritant-induced asthma, a type of OA. Induced sputum cytology can confirm airway inflammation, but specific inhalation challenge is the reference standard diagnostic test. Inhalation challenges are relatively safe, with the most severe reactions occurring with low-molecular-weight agents. Indirect health care costs account for about 50% of total asthma costs. Workers with poor asthma control (WRA or non-WRA) are less likely to be employed. Income loss is a major contributor to the indirect costs of WRA. Overall, asthma outcomes probably are worse for adult-onset than for childhood-onset asthma but better for OA than adult-onset non-WRA. Important aspects of management of OA are rapid and proper confirmation of the diagnosis and reduction of exposure to sensitizers or irritants at work and home.

Effect of pregnancy in asthma on health care use and perinatal outcomes

It is generally known that pregnancy in asthmatic patients increases the risk of asthma exacerbations and poor perinatal outcomes. However, the effect of pregnancy in asthmatic patients on health care use is not known well. In addition, its effect on perinatal outcomes is still controversial because of study limitations caused by ethical issues. National Health Insurance claim data are an ideal resource for studying real-world health care use patterns of asthma. We sought to evaluate the effect of pregnancy on asthma in terms of asthma-related health care use and prescription patterns in concert with the effect of asthma exacerbations on adverse pregnancy outcomes. Among all asthmatic patients in the Korean National Health Insurance claim database from January 2009 to December 2013, pregnant women who delivered in 2011 with pre-existing asthma were enrolled. Analyses included asthma-related health care use and prescription patterns compared between pregnant asthmatic women and nonpregnant female asthmatic control subjects, as well as within the pregnant subjects from before pregnancy throughout postpartum periods. In addition, the association between asthma exacerbation during pregnancy and adverse pregnancy outcomes was assessed. A total of 3,357 pregnant asthmatic patients were compared with 50,355 nonpregnant asthmatic patients, and 10,311 pregnant patients were included to determine the effect of asthma exacerbations on adverse pregnancy outcome in the study. Pregnant asthmatic patients underwent more asthma-related hospitalizations (1.3% vs 0.8%, P = .005) but had significantly fewer outpatient visits and prescriptions for most asthma medications than nonpregnant asthmatic patients. The proportion of patients ever hospitalized gradually increased throughout pregnancy (first trimester, 0.2%; second trimester, 0.5%; and third trimester, 0.7%; P = .018). The prevalence of asthma exacerbation during pregnancy was 5.3%, and the patients who had acute exacerbation during pregnancy had significantly higher asthma-related health care use in terms of hospitalization, intensive care unit admission, and emergency department and outpatient visits within 1 year before delivery than those who had not. However, asthma exacerbation during pregnancy was not significantly related to adverse perinatal outcomes, except for cesarean section (27.1% vs 18.9%, P < .001). All exacerbations were managed with systemic corticosteroids, and the patients who ever experienced acute exacerbations maintained asthma medications, including inhaled corticosteroid-based inhalers, throughout the pregnancy period. Pregnancy profoundly affects asthma-related health care use but to a different degree depending on whether the patient experienced an exacerbation. Asthma exacerbation during pregnancy is not associated with adverse pregnancy outcomes while managed appropriately with systemic corticosteroids. However, further studies are needed to clarify the effect of asthma control on perinatal outcome and delivery method.

Respiratory diseases in pregnancy

Pulmonary diseases are one of the major indirect causes of maternal deaths. Pregnancy is a unique physiologi- cal state during which changes occur in all systems of the body to meet metabolic needs of both the mother and growing foetus. Enlarging uterus and increasing hormonal levels cause changes in volumes and mechanics of lungs. Understanding the basic physiology of the cardiovascular and respiratory changes during pregnancy along with the pathology of disease processes are vital in making therapeutic decisions. Pre-existing conditions like asthma, tuberculosis, and acute illnesses like pneumonia, acute respiratory distress syndrome (ARDS), pneumothorax can have calamitous effect on mother and child health. Continual foetal monitoring throughout pregnancy is very important in early recognition of foetal jeopardy.

Current status of endoscope reprocessing in Korea.

Current status of endoscope reprocessing in Korea.

Two year effects of food allergen immunotherapy on quality of life in caregivers of children with food allergies

BackgroundFood allergy (FA) can have serious psychosocial and economic repercussions on food-allergic children and their caregivers and be associated with negative effects on their quality of life. Food allergen immunotherapy (IT) is a promising experimental therapy but can be linked to anxiety. This study investigated the effects of IT on FA-specific health-related quality of life (HRQL) over a 24 month-follow-up in caregivers of children with single and multiple food allergies. We hypothesized that characteristics such as age, asthma at baseline and respiratory allergic reactions during therapy were key characteristics that influenced HRQL scores.MethodsA validated Food Allergy Quality of Life – Parental Burden Questionnaire (FAQL-PB) was used to assess HRQL. It was randomly distributed to and filled out by caregivers of 57 food-allergic children enrolled in clinical trials of IT. The same parent answered the FABQL-PB questionnaire at baseline and for 6-month, 12- month, 18- month, and 24-month time points on IT.ResultsCaregiver HRQL improved significantly (change < - 0.5, p <0.0001) at each follow-up time point compared to baseline. The percentages of caregivers with improvement in HRQL progressively increased (92% at 24 month-follow-up time point compared to baseline). HRQL improved more in caregivers of participants older than 10 years or desensitized to more than 4 food allergens than those who were not (p <0.0001). Caregivers of participants with pre-existing asthma or dose-related respiratory allergic reactions had less improvement in HRQL than those who did not (p <0.01).ConclusionIT lead to improvement in caregiver HRQL. Certain characteristics were associated with greater improvements in caregiver HRQL.Electronic supplementary materialThe online version of this article (doi:10.1186/1710-1492-10-57) contains supplementary material, which is available to authorized users.

A systematic review of associations between environmental exposures and development of asthma in children aged up to 9 years

ObjectivesChildhood asthma is a complex condition where many environmental factors are implicated in causation. The aim of this study was to complete a systematic review of the literature describing associations...

Swimming facilities and work-related asthma

Background: Exposure to chlorinated water in swimming facilities may aggravate preexisting asthma or cause new onset asthma. This may be a particular problem for individuals who work and therefore spend prolonged time at swimming facilities. Chloramines formed by the interaction of chlorine-based disinfection products with the nitrogen in water from human sweat, urine and skin cells are the suspected causal agents. Methods: Cases were reviewed from the state surveillance systems in California (CA), Michigan (MI) and New Jersey (NJ) to identify individuals with confirmed work-related asthma (WRA) attributed to exposures in swimming pools, water parks or hydrotherapy spas. A standardized method was used to confirm cases. Results: A total of 44 confirmed cases of WRA were identified; 17 from 1994 to 2011 in CA, 15 from 1991 to 2012 in MI and 12 from 1990 to 2011 in NJ. A majority (52.2%) of the cases were new onset; 31.8% secondary to an acute exposure incident and 20.4% to repeated exposure. These represented 0.3–1.6% of all confirmed cases of WRA received during these time periods. Maintenance workers (34.9%) and lifeguards (31.8%) were the most common occupations. Conclusions: Swimming pool workers were identified from three states where the pool environment was either a trigger of preexisting asthma or associated with new onset of WRA. Regulations to require air monitoring and improvements in ventilation are recommended to reduce exposure levels of chloramines, the presumed etiologic agents. Clinical assessment of patients with asthma should include consideration of the effect on respiratory symptoms from exposures in a swimming pool environment.

Seasonal Variation in Schools’ Indoor Air Environments and Health Symptoms among Students in an Eastern Mediterranean Climate

ABSTRACTThe indoor air quality (IAQ) in classrooms highly affects the health and productivity of students. This article aims to clarify seasonal variation in indoor environment and sick building syndromes (SBS) symptoms in an Eastern Mediterranean climate. A series of field measurements were conducted during the fall and winter seasons from October 2011 to March 2012 in 12 naturally ventilated schools located in the Gaza Strip. Data on environmental perception and health symptoms were obtained from 724 students by using a validated questionnaire. The results showed that indoor PM10 and PM2.5 concentrations were 426.3 ± 187.6 μg/m3 and 126.6 ± 94.8 μg/m3, respectively. The CO2 concentrations and ventilation rate widely exceeded their reference values during the winter season. The prevalence rates of general symptoms were relatively high at baseline assessment in the fall season and increased significantly during follow-up in the winter season. Significant increases in disease symptoms such as mucosal irritation and pre-existing asthma symptoms among students could be related to poor indoor air quality. Five distinct groups of SBS symptoms from factor analysis of students’ related symptoms were significantly correlated with PM10 and PM2.5, CO2, ventilation rate, and indoor temperature. As vulnerable children, this situation negatively affects their school performance and health.

Mycoplasma pneumoniae CARDS toxin exacerbates ovalbumin-induced asthma-like inflammation in BALB/c mice.

Mycoplasma pneumoniae causes a range of airway and extrapulmonary pathologies in humans. Clinically, M. pneumoniae is associated with acute exacerbations of human asthma and a worsening of experimentally induced asthma in mice. Recently, we demonstrated that Community Acquired Respiratory Distress Syndrome (CARDS) toxin, an ADP-ribosylating and vacuolating toxin synthesized by M. pneumoniae, is sufficient to induce an asthma-like disease in BALB/cJ mice. To test the potential of CARDS toxin to exacerbate preexisting asthma, we examined inflammatory responses to recombinant CARDS toxin in an ovalbumin (OVA) murine model of asthma. Differences in pulmonary inflammatory responses between treatment groups were analyzed by histology, cell differentials and changes in cytokine and chemokine concentrations. Additionally, assessments of airway hyperreactivity were evaluated through direct pulmonary function measurements. Analysis of histology revealed exaggerated cellular inflammation with a strong eosinophilic component in the CARDS toxin-treated group. Heightened T-helper type-2 inflammatory responses were evidenced by increased expression of IL-4, IL-13, CCL17 and CCL22 corresponding with increased airway hyperreactivity in the CARDS toxin-treated mice. These data demonstrate that CARDS toxin can be a causal factor in the worsening of experimental allergic asthma, highlighting the potential importance of CARDS toxin in the etiology and exacerbation of human asthma.

The safety of asthma medications during pregnancy: an update for clinicians.

Pregnancy may be complicated by new onset or preexisting asthma. This article reviews the recognition and management of asthma during pregnancy, as well as general principles of asthma medication use during pregnancy.