Clinical diagnosis of current asthma: predictive value of respiratory symptoms in the SAPALDIA study. Swiss Study on Air Pollution and Lung Diseases in Adults

TREM1 is involved in the mechanism between asthma and lung cancer by regulating the Toll‑like receptor signaling pathway

Lung cancer and asthma are both global health problems with significant economic consequences. Recent studies have demonstrated that asthma may be a risk factor for lung cancer. The present study aimed to explore the pathogenesis between these two diseases through a comprehensive analysis. Differentially expressed genes (DEGs) screened in the asthma-related GSE165934 dataset were analyzed to find relevant inflammatory pathways. Overlapping genes regulated by inflammatory pathways and lung cancer-DEGs from The Cancer Genome Atlas (TCGA) were obtained and subjected to survival and gene-wide mutation analyses, and nomogram construction to determine the hub gene. The hub gene was further analyzed through expression validation, immunoassays and functional experiments to investigate its role and mechanism in lung cancer. Functional enrichment analysis showed that 1,275 DEGs from GSE165934 were closely associated with the Toll-like receptor signaling pathway, and 8 overlapping genes were identified from 12 genes regulated by the Toll-like receptor signaling pathway and 3,134 TCGA-DEGs. After a series of bioinformatics analyses, it was found that triggering receptor expressed on myeloid cells 1 (TREM1) was the hub gene involved in the mechanism of asthma and lung cancer. TREM1 was also found to be a suppressor gene in lung cancer correlated with immune cells, immune checkpoint-related genes and tumor mutational burden score. Additionally, the results of Cell Counting Kit-8 and Transwell experiments demonstrated that overexpression of TREM1 could significantly inhibit the invasion, proliferation and migration of lung cancer cells. Reverse transcription-quantitative PCR and western blotting demonstrated that the overexpression of TREM1 could also significantly reduce the level of Toll-like receptor signaling pathway proteins. The present findings suggest that TREM1 is associated with the mechanism of asthma and lung cancer through its regulation of the Toll-like receptor signaling pathway. Furthermore, TREM1 may serve as a potential treatment target and prognostic indicator for patients with lung cancer.

The bidirectional association between wheezing and obesity during adolescence and the beginning of adulthood in the 1993 birth cohort, Pelotas, Brazil

Objective: To analyze the bidirectional association between wheezing and obesity during adolescence and the beginning of adulthood in a cohort in southern Brazil. Methods: This prospective longitudinal study used data from the 1993 birth cohort in Pelotas, Brazil. The following outcome variables were measured at 22 years of age: self-reported wheezing during the last 12 months and obesity (BMI = 30 kg/m2). The following exposure variables were measured at ages 11, 15, and 18: self-reported wheezing (no wheezing or symptom presentation in 1, 2, or 3 follow-ups) and obesity (non-obese or obese in 1, 2, or 3 follow-ups). Crude and adjusted logistical regression stratified by sex were used in the analyses. The reference category was defined as participants who presented no wheezing or obesity. Results: A total of 3,461 participants had data on wheezing and 3,383 on BMI. At 22 years of age, the prevalence of wheezing was 10.1% (95%CI: 9.1; 11.2), and obesity, 16.2% (95%CI: 15.0; 17.6). In females, the presence of wheezing in two follow-ups revealed a 2.22-fold (95%CI: 1.36; 3.61) greater chance of developing obesity at 22 years of age. Meanwhile, the presence of obesity in two follow-ups resulted in a 2.03-fold (95%IC: 1.05; 3.92) greater chance of wheezing at 22 years of age. No associations were found between wheezing and obesity in males. Conclusions: The obtained data suggest a possible positive bidirectional association between wheezing and obesity, with greater odds ratios in the wheezing to obesity direction in females and in the category of occurrence of exposure in two follow-ups.

Microbiome profiling of uncinate tissue and nasal polyps in patients with chronic rhinosinusitis using swab and tissue biopsy

Chronic rhinosinusitis (CRS) is characterized according to the presence or absence of nasal polyps (NPs) and displays nasal microbiota dysbiosis. However, optimal sampling methods of the nasal microbiome in CRS have not been identified. We aimed to assess the microbial composition in patients with CRS, comparing different sampling methods (swab and tissue biopsy), tissue types (uncinate tissue and NP), and disease subtypes. Samples were obtained by swabbing the middle meatus and taking a biopsy of uncinate tissue (UT) in patients with CRS with (CRSwNP, N = 8) or without NP (CRSsNP, N = 6) and controls (N = 8). NPs were also harvested in CRSwNP. DNAs were extracted from fifty-two samples and analyzed by 16S rRNA gene amplicon sequencing. As a result, a great interpersonal variance was observed in nasal swabs, while UT samples presented distinct microbiome with low inter-personal differences. Moreover, the UT microbiomes were further differentiated into three clusters which are associated with disease status (control, CRSsNP, and CRSwNP). Compared to UT, NP revealed a unique microbiome profile with significantly less bacterial diversity. Prevotella was the genus whose abundance was negatively correlated with disease severity in NP. In conclusion, tissue samples are better specimens than nasal swabs for assessing the microbiomes of CRS patients. Several bacteria in UT and NP tissues revealed an association with clinical severity of CRSwNP.

Oral prednisolone for acute lower respiratory tract infection in clinically unrecognised asthma: an exploratory analysis of the Oral Steroids for Acute Cough (OSAC) randomised controlled trial

Background

Acute lower respiratory tract infection (ALRTI) is often treated in primary care with antibiotics. The recent Oral Steroids for Acute Cough (OSAC) randomised controlled trial (RCT) showed corticosteroids were not an effective alternative in adults without a diagnosis of asthma with ALRTI.

Aim

To investigate if corticosteroids are beneficial for ALRTI in patients with unrecognised asthma.

Design & setting

An exploratory analysis was undertaken of the primary care OSAC trial.

Method

A subgroup analysis was performed in patients who responded ‘yes’ to the following International Primary Care Airways Group (IPCAG) question: did you have wheeze and/or at least two of nocturnal cough or chest tightness or dyspnoea in the past year. Sensitivity analyses were carried out on those who answered ‘yes’ to wheeze and at least two of the nocturnal symptoms. The primary outcomes were as follows: duration of cough (0–28 days, minimum clinically important difference [MCID] of 3.79 days) and mean symptom severity score (range 0–6; MCID 1.66 units).

Results

In total, 40 (10%) patients were included in the main analysis: mean age 49 years (standard deviation [SD] = 17.9), 52% male. Median cough duration was 3 days in both prednisolone (interquartile range [IQR] = 2–6 days) and placebo (IQR = 1–6 days) groups (adjusted hazard ratio [HR] = 1.10; 95% confidence interval [CI] = 0.47 to 2.54; P = 0.83), equating to 0.24 days longer in the prednisolone group (95% CI = 1.23 days shorter to 2.88 days longer). Mean symptom severity difference was –0.14 (95% CI = –0.78 to 0.49; P=0.65) comparing prednisolone with placebo. Similar findings were found in the sensitivity analysis.

Conclusion

No evidence was found to support the use of corticosteroids for ALRTI in patients with clinically unrecognised asthma. Clinicians should not use the IPCAG questions to target oral corticosteroid treatment in patients with ALRTI.

A cross sectional survey to estimate prevalence and associated factors of asthma on Reunion Island, Indian Ocean

Background

Previous studies on asthma mortality and hospitalizations in Reunion Island indicate that this French territory is particularly affected by this pathology. Epidemiological studies conducted in schools also show higher prevalence rates in Reunion than in Mainland France. However, no estimates are provided on the prevalence of asthma among adults. In 2016, a cross-sectional survey was conducted to estimate the prevalence of asthma and to identify its associated factors in the adult population of Reunion Island.

Methods

A random sample of 2419 individuals, aged 18–44 years, was interviewed by telephone using a standardized, nationally validated questionnaire. Information was collected on the respiratory symptoms, description of asthma attacks and triggering factors for declared asthmatics, as well as data on the indoor and outdoor home environment. “Current asthma” was defined as an individual declaring, at the time of the survey, having already suffered from asthma at some point during his/her life, whose asthma was confirmed by a doctor, and who had experienced an asthma attack in the last 12 months or had been treated for asthma in the last 12 months. “Current suspected asthma” was defined as an individual presenting, in the 12 months preceding the study, groups of symptoms suggestive of asthma consistent with the literature.

Results

The estimated prevalence of asthma was 5.4% [4.3–6.5]. After adjustment, women, obesity, a family member with asthma, tenure in current residence and presence of indoor home heating were associated with asthma. The prevalence of symptoms suggestive of asthma was 12.0% [10.2–13.8]. After adjustment, marital status, passive smoking, use of insecticide sprays, presence of mold in the home and external sources of atmospheric nuisance were associated with the prevalence of suspected asthma.

Conclusion

Preventive actions including asthma diagnosis, promotion of individual measures to reduce risk exposure as well as the development of study to improve knowledge on indoor air allergens are recommended.

Systematic Approach to Asthma of Varying Severity

Asthma is a serious global health issue and asthma guidelines recommend a stepwise approach to management with goals to achieve control and minimize future risk. Prior to escalation of pharmacotherapy, steps to confirm accurate diagnosis as well as address comorbidities and triggers are critical to effective asthma management. This article provides readers with a structured approach to evaluation and management of asthma of varying severity.

Asthma: Diagnosis and Treatment

Asthma is an obstructive lung disease affecting >230 million people worldwide and a significant cause of morbidity in patients of all ages. It is a heterogeneous disease with a complex pathophysiology and phenotype. Diagnosis is made with thorough history-taking and physical examination, and the condition is characterised by variable airflow obstruction and airway hyper-responsiveness. Understanding the severity of the disease is important, and treatment is aimed at symptom control and the prevention of future exacerbations. Pharmacologic treatment with beta-agonists for intermittent asthma and inhaled corticosteroids and a combination of inhaled corticosteroids and long-acting beta-2 agonists for persistent asthma are recommended. Additional and alternative treatments with leukotriene modifiers, anticholinergics, biologics, and bronchial thermoplasty are also available. However, understanding an individual’s disease phenotype, endotype, and comorbidities is necessary for asthma treatment, with appropriate consultation with asthma specialists required for those with severe asthma.

Predicting asthma in older adults on the basis of clinical history

BACKGROUND

The diagnosis of asthma is not always straightforward and can be even more challenging in older adults. Asthma is ideally confirmed by demonstration of variable expiratory airflow limitation. However, many patients with asthma do not demonstrate airflow obstruction nor show bronchodilator reversibility. We aimed to investigate predictors for a positive bronchial challenge test with methacholine in older adults being evaluated for asthma.

METHODS

This is a diagnostic accuracy study with a cross-sectional design. Participants ≥60 years with suspected asthma and a negative postbronchodilator response on spirometry were included. All participants underwent a methacholine challenge test (MCT). We assessed the value of standard asthma screening questions and additional clinical questions to predict the MCT results. A multivariable logistic regression model was developed to assess the variables independently impacting the odds of a positive MCT result.

RESULTS

Our study included 71 participants. The majority were female (n = 52, 73.2%) and the average age was 67.0 years. Those with a positive MCT (n = 55, 77.5%) were more likely to have wheezing or coughing due to allergens (n = 51, 92.7% vs. n = 12, 75.0%; P = 0.004) and difficulty walking several blocks (n = 14, 25.5% vs. n = 1, 6.3%, P = 0.009). After adjustment, having wheezing or coughing due to allergens (OR = 4.2, 95% CI 1.7-7.8, P = 0.012) remained the only significant independent predictor of a positive MCT.

CONCLUSIONS

In older adults with suspected asthma, questioning about wheezing or coughing due to allergens provides a modest independent value to predict a MCT result in those who previously had a negative postbronchodilator response on spirometry.

Predictive value of respiratory symptoms for the diagnosis of pollen-induced seasonal asthma among children and adults in Inner Mongolia

Background

The diagnosis of asthma is made on the basis of variable respiratory symptoms and supported by objective evidence of variable airflow limitation. However, spirometry and bronchoprovocation tests may not be routinely available in resource-scarce settings or in the context of large-scale epidemiological studies. There is a gap in knowledge about the predictive value of respiratory symptoms for the diagnosis of pollen-induced asthma.

Objective

The aim of this study was to investigate the predictive value of self-reported respiratory symptoms for diagnosing pollen-induced asthma.

Patients and methods

We recruited 1,161 patients with respiratory symptoms who presented to the respiratory medicine outpatient clinic of two central hospitals in Inner Mongolia during the pollen season of July–September 2015. All patients were interviewed by a respiratory physician and completed a questionnaire survey, lung function tests and skin prick tests for common inhaled allergens.

Results

A total of 392 patients (33.8%) were diagnosed with asthma and 292 (25.2%, 160 adults, 132 children) with pollen-induced asthma. Respiratory symptoms of cough, wheezing, dyspnea, chest pain and nocturnal awakenings due to breathlessness were all associated with increased odds of being diagnosed with pollen-induced asthma, with cough being the most common symptom in both adults and children, giving a sensitivity of 90.6% in adults and 88.6% in children. Wheezing was the most specific symptom (78% and 89.5% in adults and children, respectively) compared to other symptoms. Overall, the positive predictive value of respiratory symptoms was poor for diagnosing pollen-induced asthma, with the exception of wheezing in children which had a high positive predictive value of 72.7%.

Conclusion

Cough was the predominant symptom in adults and children with pollen-induced asthma. Wheezing was a reliable predictor of pollen-induced asthma in children. In adults, respiratory symptoms were not sufficiently reliable for diagnosing pollen-induced asthma.

Assessment of asthma severity in adults with ever asthma: A continuous score

BACKGROUND

In epidemiological studies, continuous measures of asthma severity should be used to catch the heterogeneity of phenotypes. This study aimed at developing and validating continuous measures of asthma severity in adult patients with ever asthma from the general population, to be used in epidemiological studies.

METHODS

Respiratory symptoms, anti-asthmatic treatment and lung function were measured on 520 patients with ever asthma aged 20-64 years from the general Italian population (GEIRD study; 2007/2010). The variables that represent the same dimension of asthma severity were identified through an exploratory factor analysis and were summarized through a multiple factor analysis.

RESULTS

Only respiratory symptoms and anti-asthmatic treatment were summarized in a continuous score (STS). STS ranges from 0 (no symptoms/treatment) to 10 (maximum symptom frequency and treatment intensity). STS was positively correlated with the Global Initiative for Asthma classification of asthma severity computed on the 137 cases with a doctor's diagnosis (Spearman's coefficient = 0.61, p-value<0.0001) (concurrent validity). Furthermore, using a cohort of 1,097 European asthmatics (ECRHS II study; 1999/2002), increasing STS levels at baseline (1991/1993) were positively associated with long-term outcomes (hospitalization and lost workdays for breathing problems, asthma attack frequency and use of asthma controllers) (predictive validity). Finally, the STS scores computed from the GEIRD and ECRHS II data were comparable (Lin's coefficient = 0.95, p-value<0.0001) (replication analysis).

CONCLUSIONS

STS is a valid and replicable measure of asthma severity in adults, which could be used in association studies.

Resurvey of symptomatics of the Jaipur district population and suggestion for alternative diagnostic criteria of asthma for epidemiological surveys

INTRODUCTION

The prevalence of asthma in Jaipur district of Rajasthan was reported as 0.96% in an earlier survey. It was far below the national average of 2.38%. It was reasoned then that this could be due to under diagnosis of asthma in the Jaipur population.

MATERIAL AND METHODS

A resurvey of the symptomatics, not diagnosed as asthma at time of the original survey was, therefore, undertaken. The resurvey data were analysed and those who now fulfilled the twin criteria for diagnosis of asthma, as used in the original survey, were diagnosed as having asthma. The original data of these newly diagnosed asthma patients were reanalyzed in search for an alternative diagnostic criterion.

RESULTS

Of the 382 symptomatics, 344 (90%) could be resurveyed and of them, 85 now fulfilled the twin diagnostic criteria for asthma. The reanalysis of the original survey data of these patients revealed that presence of shortness of breath (SOB) had the highest sensitivity, the presence of allergic symptoms in self or the family had the highest specificity and the presence of wheezing had the highest odds ratio (OR) for diagnosing asthma. Further, the OR for diagnosing asthma increased further and was highest with the presence of SOB and 2 additional symptoms. With the use of the "symptom criteria" for diagnosis of asthma i.e. the presence of SOB with 2 additional symptoms, it would have been possible to diagnose majority of the missed cases at the time of the original survey itself.

CONCLUSIONS

Based on this study data it can be concluded that (a) the twin criteria for diagnosing asthma as used in earlier surveys led to under diagnosis of asthma and (b) the use of symptom criteria alone effectively checks the problem of under diagnosis of asthma. The symptom criteria are being suggested as an alternative method for use in future epidemiological surveys on asthma.

Wheezing in tobacco farm workers in southern Brazil

BACKGROUND

Tobacco workers are exposed to several respiratory occupational sensitizers.

METHODS

A representative cross-sectional study was carried out on 2469 tobacco family farming growers. Gender-stratified multivariate analyses evaluated the association between wheezing and socio-demographic, behavioral, and occupational variables.

RESULTS

Wheezing prevalence was 11.0% with no difference between genders. Among men, age, smoking, strenuous work, pesticide use, contact with vegetable dust and dried tobacco dust, lifting sticks with tobacco leaves to the curing barns, and green tobacco sickness (GTS) were risk factors for wheezing. Among women, family history of asthma, tying hands of tobacco, strenuous work, contact with chemical disinfectants, and GTS were positively associated with wheezing. Harvesting lower tobacco leaves was a protective factor for the outcome in both genders.

CONCLUSIONS

Pesticides, dusts exposure, and GTS were risk factors for wheezing. The synergic effect of these factors needs to be better evaluated to improve prevention.

Fluticasone propionate in clinically suspected asthma patients with negative methacholine challenge test

INTRODUCTION

Despite reports of response to steroid inhaler in some clinically suspected asthma patients with negative methacholine challenge test (CSA/MCT-), treatment in these patients has not been prospectively studied.

OBJECTIVE

We studied the role of a 12 week high dose inhaled fluticasone trial in CSA/MCT- patients.

METHODS

After a 2 week run-in period, CSA/MCT-patients were treated with 12 weeks of Fluticasone propionate 1000 µg/day. The Asthma Control Test (ACT), numeric cough score (NCS) and bronchodilator use were compared with their pretreatment values.

RESULTS

Thirty-four of 42 CSA/MCT-patients completed the study. Mean pretreatment ACT score (pACT) was significantly increased after treatment (14.7 ± 3.37 to 20.9 ± 3.1, P < 0.001). Posttreatment values of daytime (1.0 ± 1.0) and night-time (0.6 ± 0.9) NCS decreased compared to their pretreatment values (2.8 ± 1.1 and 1.9 ± 1.3, respectively; P < 0.001). ACT score change (ΔACT) were significantly greater in those with pACT < 15 than in those ≥15 (P < 0.001) . Fifteen of 21 patients with ΔACT > 5 did not need to use bronchodilator for their symptom relief. Wheeze disappeared in all six patients with ΔACT > 5 after the trial. Six months after the study, steroid inhaler continued to be used by 72.2% of patients.

CONCLUSION

A significant portion of CSA/MCT- (especially those with pretreatment ACT score <15) respond to high dose fluticasone inhaler in terms of symptoms relief, disappearance of wheeze and need to bronchodilator use. ΔACT could not be predicted with any individual symptoms or signs before MCT, % FEV1 decline or symptoms during MCT and exhaled nitric oxide.

mHealth Clinic Appointment PC Tablet: Implementation, Challenges and Solutions

BACKGROUND

Patients requiring daily intravenous (IV) home parenteral nutrition (HPN) would benefit from in-home professional observation to improve self-care, to assess, detect and prevent serious complications.

AIMS

The study aims are to assess the viability and utility of conducting mobile healthcare (mHealth) videoconference assessments with patients managing lifelong daily 12-hour IV nutrition infusions in their homes. The challenges and solutions to implementing mobile personal computer (PC) tablet based clinic appointments are described.

METHODS

A wireless Apple iPad Mini™ mobile touch-screen tablet computer with 5 mega-pixel camera was loaned to patients. Each tablet had Polycom RealPresence software and a fourth generation (4G) mobile telecommunications data plan. These supported audio-visual mobile videoconferencing encrypted connections between health professionals in their offices and HPN patients and their family members in their homes. Patients' and professionals' evaluations of their mHealth clinic experiences are collected.

RESULTS

Patients (mean age = 41.9, SD = 2.8 years) had been prescribed 12-hour home parenteral nutrition (HPN) infusions daily due short bowel disorders. Patients had been on HPN from 1 to 10 years (M=4, SD=3.6). Evaluation of clinic appointments revealed that 100% of the patients (n=45) and the professionals (n=6) indicated that they can clearly hear and easily see one another. The mHealth audio-visual interactions were highly rated by patients and family members. Professionals highly rated their ability to obtain a medical history and visual inspection of patients. Several challenges were identified and recommendations for resolutions are described.

DISCUSSION

All patients and professionals highly rated the iPad mHealth clinic appointments for convenience and ease of communicating between homes and offices. An important challenge for all mHealth visits is the clinical professional's ability to make clinically accurate judgments about what they observed and heard from the patients. Following our solutions for obtaining clear visuals with the iPad can improve ability to make clinical assessments.

Effect of a smoking ban on respiratory health in nonsmoking hospitality workers: a prospective cohort study

OBJECTIVE

The aim of this study was to examine the effect of a smoking ban on lung function, fractional exhaled nitric oxide, and respiratory symptoms in nonsmoking hospitality workers.

METHODS

Secondhand smoke exposure at the workplace, spirometry, and fractional exhaled nitric oxide were measured in 92 nonsmoking hospitality workers before as well as twice after a smoking ban.

RESULTS

At baseline, secondhand smoke-exposed hospitality workers had lung function values significantly below the population average. After the smoking ban, the covariate-adjusted odds ratio for cough was 0.59 (95% confidence interval, 0.36 to 0.93) and for chronic bronchitis 0.75 (95% confidence interval, 0.55 to 1.02) compared with the preban period.

CONCLUSIONS

The below-average lung function before the smoking ban indicates chronic damages from long-term exposure. Respiratory symptoms such as cough decreased within 12 months after the ban.

Sinus microbiota varies among chronic rhinosinusitis phenotypes and predicts surgical outcome

BACKGROUND

Chronic rhinosinusitis (CRS) is a prevalent multifactorial disease process in which bacteria are believed to play a role in the propagation of inflammation. Multiple subtypes of CRS have been described based on clinical and pathologic features, but a detailed examination of the sinus microbiota in patients with CRS and its clinical subtypes has yet to be performed.

OBJECTIVE

We sought to examine the resident microbiota of CRS subtypes and determine whether bacterial diversity is a predictor of disease outcomes.

METHODS

Sinus swabs from patients with CRS and healthy subjects collected during endoscopic sinus surgery were analyzed by means of molecular phylogenetic analysis of 16S rDNA pyrosequences.

RESULTS

Fifty-six patients with CRS and 26 control subjects were studied. Biodiversity was similar between the CRS and control groups. Among the CRS subtypes examined, only 2 conditions (presence of purulence and comorbid condition of asthma) were associated with significant alterations in microbial community composition. In 27 patients with CRS who were followed postoperatively, those with better outcomes had more diverse bacterial communities present at the time of surgery, along with higher relative abundances of Actinobacteria.

CONCLUSION

Analysis of microbiota in a large cohort reveals that particular CRS phenotypes (asthma and purulence) are characterized by distinct compositions of resident bacterial communities. We found that bacterial diversity and composition are predictors of surgical outcome, promoting the concept of community ecology in patients with CRS.

Value of past clinical history in differentiating bronchial asthma from COPD in male smokers presenting with SOB and fixed airway obstruction

Objective:

Differentiating asthma from chronic obstructive pulmonary disease (COPD) is difficult. Steroid trial may be of help but has several pitfalls. The present study aims to assess the value of past clinical profile of asthma and its differential diagnosis from COPD in male smokers and thereby to formulate clinical parameters to diagnose bronchial asthma in such patients.

Patients and Methods:

Male smokers who reported at the Respiratory Medicine Department of the National Institute of Medical Sciences (NIMS) Hospital, Jaipur, (India), with shortness of breath (SOB) and showing less than 12% postbronchodilator bronchial reversibility (BR) on spirometry were recruited. These patients were given oral prednisolone 1 mg/kg for two weeks. Post steroid (PS) spirometry was performed to ascertain BR. The past clinical history was recorded and analyzed to determine if it is of any use in differentiating asthma from COPD.

Result:

Out of 104 patients, four were lost to follow up, 52 were diagnosed as bronchial asthma, and the remaining 48 as COPD. It was revealed that past history of (H/O) seasonal variation, wheezing, eye allergy, nasal allergy, dust allergy, skin allergy, and family H/O asthma/allergy were positive in 50, 40, 34, 30, 18, 14, and 12 asthma patients as compared to 10, 8, 2, 4, 6, 0, and 0 in 48 COPD patients (P < 0.001). The odds ratio (OR) for diagnosing asthma was highest for the presence of any other two symptoms/variables, besides SOB, in the past (OR = 275, P < 0.0001).

Conclusion:

Past clinical history is of immense value in differentiating asthma from COPD in male smokers presenting with SOB and fixed airway obstruction.

Evaluation of implementation, compliance and acceptance of partial smoking bans among hospitality workers before and after the Swiss Tobacco Control Act

BACKGROUND

The World Health Organization recommends uniform comprehensive smoking bans in public places. In Switzerland, regulations differ between various areas and are mostly incomplete for hospitality venues. As ambiguous regulations offer more leeway for implementation, we evaluated the Swiss regulations with respect to their effects on implementation, acceptance and compliance among hospitality workers.

METHODS

In our longitudinal study, a standardized, self-administered questionnaire was mailed to a sample of 185 hospitality workers before and 4-6 month after the smoking ban came into effect. The matched longitudinal sample comprised 71 participants (repeated response rate 38.4%). We developed a seven-item acceptance scale. Logistic regressions were performed to explore the factors associated with acceptance.

RESULTS

Acceptance of smoking bans was influenced by smoking status and perceived annoyance with second-hand smoke in private. Although not statistically significant (P = 0.09), we found some indications that post-ban acceptance increased in an area with strict regulations, whereas it decreased in two areas with less stringent regulations.

CONCLUSIONS

Tobacco bans in Swiss hospitality venues are still in a period of consolidation. The incomplete nature of the law may also have had a negative impact on the development of greater acceptance.

Dietary total antioxidant capacity and current asthma in Spanish schoolchildren: a case control-control study

The aim of this work was to study the relationship between dietary total antioxidant capacity (TAC) and current asthma in a group of Spanish schoolchildren. A total of 78 Spanish schoolchildren (26 asthmatic and 52 healthy controls) were randomly selected from a cohort of 564 children (9-12 years of age). The weight and height of all subjects were recorded. A questionnaire, completed by the subjects' parents, was used to obtain personal and health information. Current asthma was established when children had ever had asthma, they had been diagnosed with asthma by a physician, and they had been treated with medications at some time in the previous 12 months. Food intake was monitored using a 3-day food record. All consumed foods were converted into energy and nutrients. Dietary TAC was evaluated using the ferric reducing antioxidant power (FRAP), radical-trapping antioxidant parameter (TRAP), and Trolox equivalent antioxidant capacity (TEAC) assays. The TAC measured using all the assays was significantly lower in children with asthma than in children without this condition (2.95 (2.10-3.75) mmol Fe(II)/day vs. 3.70 (3.08-4.49) mmol Fe(II)/day, p < 0.01; 1.50 (1.06-2.05) mmol Trolox equivalents/day vs. 2.10 (1.40-2.65) mmol Trolox equivalents/day, p < 0.05; and 1.60 (1.08-2.00) mmol Trolox equivalents/day vs. 1.85 (1.50-2.68) mmol Trolox equivalents/day, p < 0.05 for FRAP, TEAC, and TRAP, respectively). After adjusting for energy intake, children with FRAP values higher than 3.5 mmol Fe(II)/day (p50) and TEAC values higher than 1.9 mmol Trolox equivalents/day (p50) had 22.6 and 35.0 %, respectively, lower likelihood of suffering asthma episodes than children with lower values. When logistic regression analysis was performed separately for children with nonsmoker and smoker (at least one) parents, the association between dietary TAC and asthma was only observed in the nonsmoker group (OR = 0.257, 95 % CI = 0.107-0.618, p = 0.002 for FRAP; OR = 0.212, 95 % CI = 0.069-0.639, p = 0.006 for TEAC; and OR = 0.264, 95 % CI = 0.091-0.769, p = 0.015 for TRAP assay).

CONCLUSION

Dietary TAC may have a favorable role in asthma in children and, specially, in those with nonsmoker parents.

Screening for occupational asthma by using a self-administered questionnaire in a clinical setting

OBJECTIVE

Because of its high prevalence, early screening for occupational asthma (OA) is crucial. We aimed to evaluate the screening performance of the Occupational Asthma Screening Questionnaire-11 items (OASQ-11) in a clinical setting.

METHODS

Between January 2009 and December 2011, 169 workers referred for potential OA to our hospital completed the OASQ-11 and underwent workups to determine the final diagnosis. The discriminative abilities of the OASQ-11 as a whole and in relation to demographic and exposure parameters were determined by the area under the receiving operator characteristic curve (AUC).

RESULTS

Model 1, consisting of the OASQ's items, showed fair discrimination (AUC, 0.69; 95% confidence interval, 0.58 to 0.80). Addition of age and exposure duration to model 1 improved discrimination (AUC, 0.80; confidence interval, 0.72 to 0.88).

CONCLUSION

A simple model consisting of the OASQ-11's items, age, and exposure duration could well discriminate subjects with OA in a clinical setting.

The microbiome of the middle meatus in healthy adults

Rhinitis and rhinosinusitis are multifactorial disease processes in which bacteria may play a role either in infection or stimulation of the inflammatory process. Rhinosinusitis has been historically studied with culture-based techniques, which have implicated several common pathogens in disease states. More recently, the NIH Human Microbiome Project has examined the microbiome at a number of accessible body sites, and demonstrated differences among healthy and diseased patients. Recent DNA-based sinus studies have suggested that healthy sinuses are not sterile, as was previously believed, but the normal sinonasal microbiome has yet to be thoroughly examined. Middle meatus swab specimens were collected from 28 consecutive patients presenting with no signs or symptoms of rhinosinusitis. Bacterial colonization was assessed in these specimens using quantitative PCR and 16S rRNA pyrosequencing. All subjects were positive for bacterial colonization of the middle meatus. Staphylococcus aureus, Staphylococcus epidermidis and Propionibacterium acnes were the most prevalent and abundant microorganisms detected. Rich and diverse bacterial assemblages are present in the sinonasal cavity in the normal state, including opportunistic pathogens typically found in the nasopharynx. This work helps establish a baseline for understanding how the sinonasal microbiome may impact diseases of the upper airways.

Forecasting peak asthma admissions in London: an application of quantile regression models

Asthma is a chronic condition of great public health concern globally. The associated morbidity, mortality and healthcare utilisation place an enormous burden on healthcare infrastructure and services. This study demonstrates a multistage quantile regression approach to predicting excess demand for health care services in the form of asthma daily admissions in London, using retrospective data from the Hospital Episode Statistics, weather and air quality. Trivariate quantile regression models (QRM) of asthma daily admissions were fitted to a 14-day range of lags of environmental factors, accounting for seasonality in a hold-in sample of the data. Representative lags were pooled to form multivariate predictive models, selected through a systematic backward stepwise reduction approach. Models were cross-validated using a hold-out sample of the data, and their respective root mean square error measures, sensitivity, specificity and predictive values compared. Two of the predictive models were able to detect extreme number of daily asthma admissions at sensitivity levels of 76 % and 62 %, as well as specificities of 66 % and 76 %. Their positive predictive values were slightly higher for the hold-out sample (29 % and 28 %) than for the hold-in model development sample (16 % and 18 %). QRMs can be used in multistage to select suitable variables to forecast extreme asthma events. The associations between asthma and environmental factors, including temperature, ozone and carbon monoxide can be exploited in predicting future events using QRMs.

Variability in the labeling of asthma among pediatricians

Objective

Few studies have examined variability among physicians in the perception and interpretation of asthma symptoms. We report the results of a pilot study to investigate the variability of symptom description and diagnostic labeling and nomenclature among a group of clinicians using standardized audiovisual presentations of asthma.

Methods

Practicing pediatricians in Wisconsin recruited from an electronic mailing list were shown the International Study of Asthma and Allergies in Childhood (ISAAC) video questionnaire online, and asked to describe the symptoms and signs they observed and suggest possible diagnostic labels for each presentation.

Results

A total of 113 pediatricians (mean age = 43 years; 56% female) responded to ≥1 of the 5 video scenes. The number of practitioners who described the principal symptom(s) of asthma depicted in the 5 sequences ranged from 5.5% for Scene 5 (featuring both dyspnea and wheeze), to 100% for Scene 4 (featuring cough). The number who suggested label of ‘asthma’ as a possible cause of the presentations ranged from 69.7% for Scene 3 (featuring nocturnal wheeze), to 92.7% for Scene 2 (featuring exercise induced wheeze).

Conclusion

There is important unexplained variation in the perceptions and labeling of asthma symptoms among pediatricians. These differences may influence the likelihood of diagnosis and the apparent prevalence of asthma. Many participants suggested that the ISAAC video be used in the education and training of pediatricians.

Prevalence and abundance of Staphylococcus aureus in the middle meatus of patients with chronic rhinosinusitis, nasal polyps, and asthma

BACKGROUND

Chronic rhinosinusitis (CRS) is an idiosyncratic and multifactorial disease process. Bacteria play a role in some patients, by infection or stimulation of inflammation. Staphylococcus aureus (SA) appears to be implicated in a number of infectious and inflammatory mechanisms, and may be particularly relevant in CRS patients with nasal polyps and asthma.

METHODS

Middle meatus swabs from control and CRS patients collected during endoscopic sinus surgery were analyzed by quantitative polymerase chain reaction (QPCR). Total bacterial count, SA prevalence, and SA abundance were examined with respect to patient demographics and disease characteristics.

RESULTS

Total bacteria, as measured by QPCR, was not statistically different between controls, CRS without nasal polyps (CRSsNP), CRS with nasal polyps (CRSwNP), or CRS with asthma groups (p < 0.09). Total bacterial counts did not correlate with disease severity as measured by Lund-Mackay computed tomography (CT) scores (p = 0.65). The prevalence of SA was similar between groups (15-25%); however, the abundance increased in CRS patients with allergic rhinitis, nasal polyps, and asthma.

CONCLUSION

The paranasal sinuses are not sterile. SA is implicated in a subset of CRS patients with nasal polyps and/or asthma. Further study is required to predict this subset of patients, and to define the mechanisms of SA pathogenesis.

Diagnosis of asthma - a new approach

Current definition of asthma involves four cornerstones: inflammation, hyperresponsiveness, bronchoconstriction, and symptoms. In research, the symptoms have had the slightest attention. According to international guidelines, the asthma symptoms are episodic breathlessness, wheeze, cough, tightness of the chest, and shortness of breath. As there are several symptoms, a primary question is how they are related to bronchoconstriction, the main clinical feature of asthma. Symptoms and lung function tests are regularly used for the evaluation of clinical health status and effect of treatment. However, there is no or poor correlation between these two variables, which means that they represent different mechanisms. Reduced lung function, such as a low FEV(1) , represents bronchial constriction, what do the symptoms represent? Some symptoms such as breathlessness and shortness of breath seem not to be evidence-based asthma symptoms. Focusing on bronchial obstruction is important in view of the potential risk of asthma attacks, but nonobstructive symptoms occur frequently and may also cause severe discomfort and poor quality of life. Interpreting all symptoms as signs of bronchoconstriction (asthma) may lead to misinterpretation when assessing health status and effect of treatment. Although a 'soft' variable, the strength of symptoms is that they are representing various mechanisms. The physiological preconditions for control and defense of respiration must be considered in the diagnostic process, regardless of inflammation, allergy, psychology, or other etiological factors. Based on studies on dyspnea in cardiopulmonary diseases, including asthma and asthma-like disorders, there seems to be a continuous spectrum of symptoms and mechanisms integrated in a single asthma syndrome.

The incidence of work-related asthma-like symptoms and dust exposure in Norwegian smelters

RATIONALE

The prevalence of respiratory symptoms among employees in smelters is positively associated with dust exposure.

OBJECTIVES

To investigate the association between the incidence of work-related asthma-like symptoms (WASTH) and dust exposure.

METHODS

All the employees were invited to participate in a 5-year longitudinal study. The outcome of WASTH was defined as the combination of dyspnea and wheezing improving on rest days or vacation in an individual who had no asthma previously. Information about smoking and occupational status was obtained from a questionnaire. A job exposure matrix of total dust was developed. Multivariate data analyses were performed using Cox regression.

MEASUREMENTS AND MAIN RESULTS

The total follow-up time of the employees (n = 2,476) was 8,469 years, and the median follow-up time for participants was 4.0 years. During the follow-up, 91 employees developed WASTH, and the corresponding incidence rate for WASTH per 1,000 person-years was 8.9 (7.3-10.9) (95% confidence interval in parentheses). The risk ratio of WASTH increased significantly (P = 0.0001) with dust exposure in the middle and high categories (1.0-2.9 and ≥ 3.0 mg/m(3)). Stratified analyses showed that the effect of current dust exposure varied with both previous exposure (PE) to dust and fumes (P = 0.006) and airflow limitation (AFL) (P = 0.033). The final analyses showed that the risk ratios for WASTH per 1 mg/m(3) increase in current dust exposure were 1.1 (0.93-1.2), 1.4 (1.1-1.8), 1.6 (1.1-2.3), and 1.9 (1.2-3.0) for the categories (PE+/AFL-), (PE-/AFL-), (PE+/AFL+, and (PE-/AFL+).

CONCLUSIONS

In conclusion, dust exposure was associated with an increased incidence of WASTH.

Microbiome complexity and Staphylococcus aureus in chronic rhinosinusitis

OBJECTIVES/HYPOTHESIS

The aim of this study was to compare microbiological culture-based and culture-independent (16S rRNA gene sequencing) methodologies for pathogen identification in chronic rhinosinusitis (CRS) patients. We hypothesized that bacterial culture and DNA sequencing would yield largely concurrent results, although sequencing would detect greater bacterial diversity, and the sinonasal microbiomes of CRS patients would differ in composition and diversity compared with non-CRS controls.

STUDY DESIGN

Cross-sectional observational study.

METHODS

Middle meatus swabs from CRS patients collected during endoscopic sinus surgery were analyzed by both clinical culture and broad-range analysis of 16S rRNA gene pyrosequences.

RESULTS

A total of 21 swab samples from 15 CRS patients and five non-CRS controls were analyzed. One CRS patient was also swabbed 3 weeks postoperatively due to evidence of purulence during a clinical visit. All subjects had positive bacterial cultures, with a mean of 2.8 isolates per subject. The most prevalent cultivars were coagulase-negative staphylococci (15/20 specimens, 75%), Staphylococcus aureus (10/20, 50%), and Propionibacterium acnes (6/20, 30%). Among 57,407 pyrosequences generated, the most prevalent were from coagulase-negative staphylococci (21/21 specimens, 100%), Corynebacterium spp (18/21, 85.7%), P acnes (16/21, 76.2%), and S aureus (14/21, 66.7%). Bacterial diversity correlated with recent antibiotic use, asthma, prior sinus surgery, and relative abundance of S aureus.

CONCLUSIONS

DNA pyrosequencing revealed greater biodiversity than culture, although in most cases culture results represented a subset of the abundant DNA sequence types. CRS patients were characterized by altered microbial composition (P = .02) and greater abundance of S aureus (P = .03).

Prevalence of asthma symptoms based on the European Community Respiratory Health Survey questionnaire and FENO in university students: gender differences in symptoms and FENO

BACKGROUND

The fractional concentration of nitric oxide in exhaled air (FENO) is used as a biomarker of eosinophilic airway inflammation. FENO is increased in patients with asthma. The relationship between subjective asthma symptoms and airway inflammation is an important issue. We expected that the subjective asthma symptoms in women might be different from those in men. Therefore, we investigated the gender differences of asthma symptoms and FENO in a survey of asthma prevalence in university students.

METHODS

The information about asthma symptoms was obtained from answers to the European Community Respiratory Health Survey (ECRHS) questionnaire, and FENO was measured by an offline method in 640 students who were informed of this study and consented to participate.

RESULTS

The prevalence of asthma symptoms on the basis of data obtained from 584 students (266 men and 318 women), ranging in age from 18 to 24 years, was analyzed. Wheeze, chest tightness, an attack of shortness of breath, or an attack of cough within the last year was observed in 13.2% of 584 students. When 38.0 ppb was used as the cut-off value of FENO to make the diagnosis of asthma, the sensitivity was 86.8% and the specificity was 74.0%. FENO was ≥ 38.0 ppb in 32.7% of students. FENO was higher in men than in women. The prevalence of asthma symptoms estimated by considering FENO was 7.2%; the prevalence was greater in men (9.4%) than women (5.3%). A FENO ≥ 38.0 ppb was common in students who reported wheeze, but not in students, especially women, who reported cough attacks.

CONCLUSIONS

The prevalence of asthma symptoms in university students age 18 to 24 years in Japan was estimated to be 7.2% on the basis of FENO levels as well as subjective symptoms. Gender differences were observed in both FENO levels and asthma symptoms reflecting the presence of eosinophilic airway inflammation.

TRIAL REGISTRATION NUMBER

UMIN000003244.

Sub-optimal asthma control in teenagers in the midland region of Ireland

BACKGROUND

Internationally, many children with asthma are not attaining achievable asthma control.

AIMS

To examine the prevalence of asthma in teenagers in four midland counties, their asthma control and the barriers, if any, to gaining control of asthma.

METHODOLOGY

International Study of Asthma and Allergies in Children (ISAAC) methodology was used in a survey of Junior Cycle Year 2 second-level students.

RESULTS

The prevalence of "wheeze ever" was 49.8%, "wheeze in the last 12 months" was 32.6% and "asthma ever" was 23.5%. Of teenagers with current asthma, 96% had evidence of sub-optimal asthma control during the previous year. For the majority of the teenagers with asthma, treatment was not guideline concordant; infrequent lung function testing, insufficient review after acute care and poor use of written asthma action plans. Barriers included lack of awareness of need for treatment.

CONCLUSIONS

If asthma guidelines are implemented fully, these children may experience better health.

Predictive factors for airway hyperresponsiveness in children with respiratory symptoms

BACKGROUND

Asthma diagnosis is a challenging condition, particularly in patients without obstructive pattern and reversibility on spirometry. Determination of airway hyperresponsiveness (AHR) may be helpful, but the procedure is time-consuming and not always practical.

OBJECTIVE

To determine the potential factors that may predict the presence of AHR in children with asthmalike symptoms but without obstructive pattern and reversibility on spirometry.

METHODS

All patients with asthmalike symptoms but without obstructive pattern and reversibility on spirometry were analyzed retrospectively between January 9, 2007, and December 30, 2009. The features of clinical history and laboratory results were analyzed with univariate and multivariate regression analysis.

RESULTS

A total of 111 children between 6 and 18 years of age, with a median age of 10.2 years, were analyzed, and AHR was detected in 67 patients (60.3%). Multivariate logistic regression analysis revealed coexistence of nocturnal cough and exercise-induced cough (odds ratio [OR], 22.1; 95% confidence interval [CI], 3.1-159.2; P = .004), eosinophilia (OR, 18.7; 95% CI, 1.9-178.7; P = .01), and borderline bronchodilator response in forced expiratory volume in 1 second (between 7% and 11%) (OR, 10.1; 95% CI, 2.1-49.1; P = .004) as significant risk factors for the presence of AHR, whereas exercise-induced dyspnea was found to be related to the absence of AHR (OR, 0.2; 95% CI, 0.1-0.8; P = .02).

CONCLUSION

In children with asthmalike symptoms but with normal spirometry, certain features of clinical history and laboratory results can strongly predict the presence of AHR and may help less frequent use of challenge tests.

Early detection and counselling intervention of asthma symptoms in preschool children: study design of a cluster randomised controlled trial

BACKGROUND

Prevention of childhood asthma is an important public health objective. This study evaluates the effectiveness of early detection of preschool children with asthma symptoms, followed by a counselling intervention at preventive child health centres. Early detection and counselling is expected to reduce the prevalence of asthma symptoms and improve health-related quality of life at age 6 years.

METHODS/DESIGN

This cluster randomised controlled trial was embedded within the Rotterdam population-based prospective cohort study Generation R in which 7893 children (born between April 2002 and January 2006) participated in the postnatal phase. Sixteen child health centres are involved, randomised into 8 intervention and 8 control centres. Since June 2005, an early detection tool has been applied at age 14, 24, 36 and 45 months at the intervention centres. Children who met the intervention criteria received counselling intervention (personal advice to parents to prevent smoke exposure of the child, and/or referral to the general practitioner or asthma nurse). The primary outcome was asthma diagnosis at age 6 years. Secondary outcomes included frequency and severity of asthma symptoms, health-related quality of life, fractional exhaled nitric oxide and airway resistance at age 6 years. Analysis was according to the intention-to-treat principle. Data collection will be completed end 2011.

DISCUSSION

This study among preschool children provides insight into the effectiveness of early detection of asthma symptoms followed by a counselling intervention at preventive child health centres.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN15790308.

Prevalence of gastro-oesophageal reflux disease symptoms and reflux-associated respiratory symptoms in asthma

Background

Gastro-oesophageal reflux disease (GORD) symptoms are common in asthma and have been extensively studied, but less so in the Asian continent. Reflux-associated respiratory symptoms (RARS) have, in contrast, been little-studied globally. We report the prevalence of GORD symptoms and RARS in adult asthmatics, and their association with asthma severity and medication use.

Methods

A cross-sectional analytical study. A validated interviewer-administered GORD scale was used to assess frequency and severity of seven GORD symptoms. Subjects were consecutive asthmatics attending medical clinics. Controls were matched subjects without respiratory symptoms.

Results

The mean (SD) composite GORD symptom score of asthmatics was significantly higher than controls (21.8 (17.2) versus 12.0 (7.6); P < 0.001) as was frequency of each symptom and RARS. Prevalence of GORD symptoms in asthmatics was 59.4% (95% CI, 59.1%-59.6%) versus 28.5% in controls (95% CI, 29.0% - 29.4%). 36% of asthmatics experienced respiratory symptoms in association with both typical and atypical GORD symptoms, compared to 10% of controls (P < 0.001). An asthmatic had a 3.5 times higher risk of experiencing a GORD symptom after adjusting for confounders (OR 3.5; 95% CI 2.5-5.3). Severity of asthma had a strong dose-response relationship with GORD symptoms. Asthma medication use did not significantly influence the presence of GORD symptoms.

Conclusions

GORD symptoms and RARS were more prevalent in a cohort of Sri Lankan adult asthmatics compared to non-asthmatics. Increased prevalence of RARS is associated with both typical and atypical symptoms of GORD. Asthma disease and its severity, but not asthma medication, appear to influence presence of GORD symptoms.

Fat intake and asthma in Spanish schoolchildren

OBJECTIVES

To study the relationship between lipid, fatty acid and lipid-rich food intake and current asthma in a group of Spanish schoolchildren.

SUBJECTS/METHODS

The subjects of this cross-sectional study were 638 Spanish schoolchildren (8-13 years of age). The weight and height of all the subjects were recorded. A questionnaire, completed by the subjects' parents, was used to obtain personal and health information. Current asthma was established when the children had ever had asthma, if they had been diagnosed with asthma by a doctor and if they had been treated with medications at some time in the previous 12 months. Food intake was monitored using a 3-day food record. All foods consumed were converted into energy and nutrients.

RESULTS

The energy derived from lipids, saturated fatty acids (SFAs) and myristic and palmitic acids was independently associated with current asthma (Odds Ratio (OR) third tertile 2.85 (1.01-8.07) P=0.049, 10.00 (0.89-111.97) P=0.002, 11.21 (1.36-92.24) P=0.002, 7.58 (1.40-41.03) P=0.022, respectively), as was the intake of butter (OR third tertile 2.97 (1.01-8.68) P=0.001). No relationship was seen between this condition and the intake of any other fatty acid, the n-6/n-3 ratio, nor the consumption of margarine, milk products, fish, meat, eggs or vegetable oils.

CONCLUSIONS

Increased intakes of SFAs, myristic and palmitic acids and butter seem to be related to the risk of current asthma in children.

Performance of the ISAAC questionnaire to establish the prevalence of asthma in adolescents: a population-based study

BACKGROUND

The epidemiology of asthma has been investigated with questionnaires, such as the International Study of Asthma and Allergies in Childhood protocol.

AIM

To investigate the performance of the questions of the International Study of Asthma and Allergies in Childhood questionnaire to diagnose asthma in adolescents.

METHODS

This is a population-based cross-sectional study of adolescents in the Syndrome of Obesity and Risk Factors for Cardiovascular Disease study. The validity of the asthma symptoms of the International Study of Asthma and Allergies in Childhood protocol was assessed by calculating sensitivity, specificity, positive and negative posttest probabilities, and Youden's Index, taking as a gold standard the history of a medical diagnosis of asthma. Risk ratios (RRs) and 95% confidence intervals (CIs), adjusting for sex and age, were calculated using Cox regression model.

RESULTS

In total, 575 adolescents were investigated. Overall, 28.7% reported a lifetime medical diagnosis of asthma, and 40.0% reported at least one episode of wheezing. Ever wheezing had the highest sensitivity (80.6%) for the diagnosis of asthma, compared with the other ISAAC questions. Adolescents who reported ever wheezing were about 8 times more likely (adjusted RR: 8.3; 95% CI: 4.9-14.2) to have ever had asthma, independent of age and sex. Symptoms within the last 12 months (wheezing, cough without cold or respiratory infection, sleep disturbed due to wheezing, wheezing due to exercise, speech limited due to wheezing) had specificity of 92.0% or higher. Dry cough at night without cold or respiratory infection was the strongest independent predictor of asthma (adjusted RR: 8.8; 95% CI: 6.1-12.7).

CONCLUSIONS

Ever wheezing is the most sensitive indicator of the diagnosis of asthma but falsely identifies a portion of adolescents as asthmatic. Symptoms of asthma in the last 12 months, such as cough without cold or respiratory infection, are rarely positive in the absence of a lifetime asthma diagnosis. The combination of ever wheezing for screening and the presence of other symptoms within the past 12 months to confirm the diagnosis could be an effective strategy to identify the prevalence of asthma in communities.

The association of BMI and sedentary time with respiratory symptoms and asthma in 5th grade schoolchildren in Kaohsiung, Taiwan

This study aimed to evaluate the association of body fatness and sedentary status with asthma and respiratory symptoms in schoolchildren in Kaohsiung, Taiwan. A questionnaire study elicited episodes of respiratory symptoms and data on lifestyle and anthropometric parameters in 1329 5th grade schoolchildren. Results showed that 12.4% of boys and 9.5% of girls had physician-diagnosed asthma, whereas 15.1% of boys and 12.4% of girls had suspected asthma. Significantly greater proportions of boys had non-exercise-induced respiratory symptoms than girls (p < 0.05). The number of respiratory symptoms was positively correlated with TV-watching time per day and self-reported sedentary time per weekend-day in girls (p < 0.05). Underweight was positively associated with one of the seven respiratory symptoms in girls (p < 0.05). At risk of overweight was positively associated with two of the seven respiratory symptoms in boys and one of the seven respiratory symptoms in girls (all p < 0.05). The risk of having physician-diagnosed asthma and suspected asthma increased 93% and 72%, respectively, in schoolchildren at risk of overweight (p < 0.05). Overweight was associated with a 78% increase in physician-diagnosed asthma (adjusted odd ratio (aOR) = 1.78, 95% CI = 1.08-2.91, p < 0.05). Higher sedentary time was significantly associated with more occurrences of one of the seven respiratory symptoms in girls (aOR = 1.05, 95% CI = 1.00-1.11, p < 0.05). Higher body mass index (BMI) was significantly correlated with longer TV-watching time per day in girls and longer self-reported sedentary time per weekday in boys (p < 0.05). In summary, schoolchildren who are at risk of overweight or overweight and/or have more sedentary time have increased risk of respiratory symptoms and asthma. Weight and sedentary statuses of schoolchildren can affect their respiratory health.

Atopy and new-onset asthma in young Danish farmers and CD14, TLR2, and TLR4 genetic polymorphisms: a nested case-control study

BACKGROUND

Evidence exists that exposure to high levels of microbial agents such as endotoxin in the farm environment decreases the risk of atopic sensitization. Genetic variation in innate immunity genes may modulate the response to microbial agents and thus influence susceptibility to asthma and atopy.

OBJECTIVE

To study potential associations between single nucleotide polymorphisms (SNPs) in CD14, Toll-like receptor 2 (TLR2), and TLR4 genes, and atopy and new-onset asthma in young farmers.

METHODS

A nested case-control study was conducted within a cohort of 1901 young Danish farmers. We genotyped 100 new-onset asthma cases and 88 control subjects for three CD14 SNPs, three TLR2 SNPs, and two TLR4 SNPs. Atopy at baseline (defined as a positive skin prick test to one or more common inhalant allergens) was found in 17 asthma cases (17.0%) and in 17 controls (19.3%).

RESULTS

The CD14/-260T allele was significantly associated with less atopy [odds ratio (OR) 0.39; 95% confidence interval (CI) 0.21-0.72, additive genetic model], whereas the CD14/-651T allele was positively associated with atopy (OR 2.53; 95% CI 1.33-4.80). Similar results were obtained by haplotype analysis. Stratified analysis by farm childhood showed stronger effects of both CD14 SNPs on atopy among farmers who were born and raised on a farm, although no significant interaction was found. No associations between CD14, TLR2, or TLR4 genotypes and new-onset asthma were found.

CONCLUSION

The CD14/-260 and CD14/-651 promoter polymorphisms are associated with atopy prevalence among young adults exposed to farm environments.

CD4dimCD25bright Treg cell frequencies above a standardized gating threshold are similar in asthmatics and controls

BACKGROUND

Thymus selected CD4(+)CD25(bright) natural regulatory Treg cells expressing FOXP3 may contribute to control of immune responses. No unique markers have been available to identify and characterize Treg. We present a gating strategy that allows enumeration of Treg on the basis of CD4 and CD25 and investigate whether asthmatics have fewer Treg than controls.

METHODS

Asthmatics and controls were selected from responses to a mailed questionnaire. CD25, CD4, HLA DR, and appropriate isotypes were recorded by flow cytometry.

RESULTS

The CD4 T cells expressing most CD25 are a separate population expressing FOXP3 and lower levels of CD4 and CD127. On a CD4 CD25 dot-plot, the CD4 MFI of Treg for 152 participants was calculated to be 0.83 +/- 0.043*MFI of CD25(bright) T-cells. CD4(dim)CD25(bright) T cells in a rectangular gate with a CD4 MFI </= 0.9 (0.83 + [2*0.043])*MFI of CD25(+) T cells were enumerated and shown to be similar for controls (median 8.34%) and asthmatics (median 10.1%). HLA DR expression on Treg correlated with CD25 expression.

CONCLUSIONS

A standardized two color gating method defines Treg. It may be applied in most clinical scenarios and is useful for sorting viable Treg. Asthmatics and controls have similar numbers of Treg.

Diagnostic tests for asthma in firefighters

BACKGROUND

Subjects with asthma do not meet medical requirements for professions such as firefighting.

OBJECTIVE

To prospectively determine the diagnostic value of respiratory symptoms and various tests used in the assessment of asthma in a cohort of firefighters.

METHODS

A questionnaire, spirometry, direct and indirect airway challenge tests, exhaled nitric oxide, and skin-prick tests were administered prospectively to 101 of 107 firefighters employed in Basel, Switzerland. Asthma was defined as the combination of respiratory symptoms with airway hyperresponsiveness.

RESULTS

Six of 101 firefighters (6%) had physician-diagnosed asthma, which could be confirmed in 4 firefighters. In contrast, asthma was diagnosed in 14% (14 of 101 firefighters). Wheezing was the most sensitive symptom for the diagnosis of asthma (sensitivity, 78%; specificity, 93%). Other respiratory symptoms showed a higher specificity than wheezing but a markedly lower sensitivity. Bronchial airway challenge with mannitol was the most sensitive (92%) and specific (97%) diagnostic test for asthma. Using a cutoff point of 47 parts per billion, nitric oxide had a similar specificity (96%) but lower sensitivity (42%) compared to the direct (methacholine) and indirect (mannitol) airway challenge tests.

CONCLUSION

Asthma was considerably underdiagnosed in firefighters. The combination of a structured symptom questionnaire with a bronchial challenge test allows to identify patients with asthma and should routinely be used in the assessment of active firefighters and may be of help when evaluating candidates for this profession.

Scoring system and clinical application of COPD diagnostic questionnaires

OBJECTIVES

In most primary care settings, spirometric screening of all patients at risk is not practical. In prior work, we developed questionnaires to help identify COPD in two risk groups: (1) persons with a positive smoking history but no history of obstructive lung disease (case finding), and (2) patients with prior evidence of obstructive lung disease (differential diagnosis). For these questionnaires, we now present a scoring system for use in primary care.

METHODS

Scores for individual questions were based on the regression coefficients from logistic regression models using a spirometry-based diagnosis of obstruction as the reference outcome. Receiver operator characteristic analysis was used to determine performance characteristics for each questionnaire. Several simplified scoring systems were developed and tested.

RESULTS

For both scenarios, we created a scoring system with two cut points intended to place subjects within one of three zones: persons with a high likelihood of having obstruction (high predictive value of a positive test result); persons with a low likelihood of obstruction (high predictive value of a negative test result); and an intermediate zone. Using these scoring systems, we achieved sensitivities of 54 to 82%, specificities of 58 to 88%, positive predictive values of 30 to 78%, and negative predictive values of 71 to 93%.

CONCLUSIONS

These questionnaires can be used to help identify persons likely to have COPD among specific risk groups. The use of a simplified scoring system makes these tools beneficial in the primary care setting. Used in conjunction with spirometry, these tools can help improve the efficiency and accuracy of COPD diagnosis in primary care.

Predictive value of respiratory symptoms and bronchial hyperresponsiveness to diagnose asthma in New Zealand

Respiratory symptoms are often used as the only diagnostic criteria for asthma in epidemiological surveys and the clinical diagnosis of asthma relies primarily on a detailed history. The aim of this study is to predict the diagnostic value of 11 different respiratory symptoms to diagnose asthma, and to determine if bronchial hyperresponsiveness (BHR) improves the predictive value of these respiratory symptoms. A random sample of 1257 subjects aged 20-44 years old in 3 different areas of New Zealand were selected between March 1991 and December 1992 to answer the European Community Respiratory Health Survey questionnaire on respiratory symptoms. Of these, 784 underwent bronchial challenge with methacholine. The prevalence of current doctor diagnosed asthma (DDA) defined as asthma confirmed by a physician and an asthma attack in the last 12 months was 8.3%. Wheezing with dyspnoea is the single best predictor of diagnosed asthma with a sensitivity of 82%, a specificity of 90% and a Youden's index of 0.72. Wheezing alone is more sensitive (94%) but less specific (76%), with a Youden's index of 0.70. The addition of BHR to asthma symptoms decreases sensitivity and increases specificity with a small increase in Youden's index to 0.75. In New Zealand adults, a history of wheezing with BHR best predicts a diagnosis of asthma but wheezing alone or with dyspnoea are the two best symptoms for predicting asthma.

An algorithmic approach to diagnosing asthma in older patients in general practice

WHAT WE NEED TO KNOW: How effective would an algorithm be in helping general practitioners diagnose asthma? What proportion of older people with undiagnosed asthma fail to recognise symptoms? What proportion of the population believe asthma does not occur in the older population? What systems or supports do GPs need to diagnose asthma more effectively? WHAT WE NEED TO DO: Work on developing a gold standard for asthma diagnosis. Develop prototype algorithms for general practice discussion. Conduct a general practice study to assess the effectiveness of an algorithm. In conjunction with GPs, develop a pilot program to increase awareness of the current asthma problem. Conduct focus-group research to identify why some people do not believe they can develop asthma for the first time in adult life. Conduct focus-group research to identify why some adults do not attribute asthma symptoms to asthma. Conduct focus groups with GPs to identify what support is needed to diagnose asthma more effectively. Consult with all stakeholders before an intervention is used. Evaluate any interventions used.

Comparison of existing symptom-based questionnaires for identifying COPD in the general practice setting

OBJECTIVE

Underdiagnosis of COPD is widespread, at least in part due to underuse of spirometry. Symptom-based questionnaires may be helpful as an adjunct to spirometry. The aim of this study was to determine which types of questions might aid in identifying COPD.

METHODOLOGY

Questionnaires were identified by literature review and input from a multinational advisory board of primary care providers. Questions were placed into groups and evaluated with respect to their ability to perform in two scenarios: (i) to identify persons with COPD from a general population (Case-finding scenario); and (ii) to distinguish persons with COPD from those with asthma (Differential Diagnosis scenario). Questions were retrospectively validated using the Third National Health and Nutrition Examination Survey data. Potential predictive ability was examined in bivariate and multivariate frameworks.

RESULTS

Four published question sets and six additional documents were included. There was agreement in the use of smoking and symptom-based questions, but important differences in the use of demographic, personal history and other information. Most question types had significant bivariate relationships with airway obstruction. In multivariate analysis, age, BMI, smoking status and pack-years, symptoms (cough, phlegm, dyspnoea, wheeze), and prior diagnosis consistent with asthma or COPD all showed significant ability to discriminate between persons with and without obstruction in a general population.

CONCLUSION

Simple self-administered questionnaires can be used to identify persons for whom spirometric testing may be especially appropriate. Development of such questionnaires will require additional study, including prospective validation of items in an appropriate clinical setting and policy recommendations on the use of these tools.

Asthma and panic in young adults: a 20-year prospective community study

RATIONALE

Psychologic factors are increasingly recognized to influence the onset and course of asthma. Previous cross-sectional community-based studies have provided evidence for a relatively specific association between asthma and panic.

OBJECTIVES

To examine concurrent and longitudinal associations between asthma and panic in young adults.

MEASUREMENTS AND MAIN RESULTS

Prospective community-based cohort study of young adults (n = 591) followed between ages 19 and 40. Information was derived from six subsequent semistructured diagnostic interviews conducted by professionals. Cross-sectionally (over the whole study period), asthma was more strongly associated with panic disorder (odds ratio [OR] = 4.0; 95% confidence interval [CI], 1.7, 9.3) than with any panic, which included panic disorder and panic attacks (OR = 2.1; 95% CI, 1.1, 4.5). Longitudinally, after adjusting for potentially confounding variables, active asthma predicted subsequent panic disorder (OR = 4.5; 95% CI, 1.1, 20.1), and the presence of panic disorder predicted subsequent asthma activity (OR = 6.3; 95% CI, 2.8, 14.0). Asthma predicted any panic (OR = 2.7; 95% CI, 1.1, 7.1), whereas any panic did not predict subsequent asthma activity. Associations were stronger in smokers than in nonsmokers, and stronger in women than in men. Smoking, early-childhood anxiety, and a family history of allergy were important confounders of the asthma-panic association.

CONCLUSIONS

This is the first long-term follow-up study on asthma and panic. It showed dose-response-type relationships between panic and asthma, and bidirectional longitudinal associations between the two conditions. It provided evidence for familial factors and smoking as possible shared etiologic explanations.

Using child reported respiratory symptoms to diagnose asthma in the community

AIMS

To study how respiratory symptoms reported by children, with or without spirometry, could help to discriminate those with asthma from those without.

METHODS

Respiratory symptoms (frequent cough, frequent phlegm, and wheezing) reported by 1646 schoolchildren (aged 8-12 years) in a respiratory questionnaire and the FEV1:FVC ratio measured with spirometry (at three different cut-off values of 0.70, 0.75, and 0.80) were compared against the criterion standard of a physician diagnosis of asthma reported by the parents.

RESULTS

The overall prevalence of asthma was 6%; more boys had asthma. Wheezing had the best discriminating ability among the three symptoms and a cut-off point at 75% was best for the FEV1:FVC ratio. Combining wheezing with an FEV1:FVC ratio <75% gave the highest discriminating ability of 83%. If the tests were applied to hypothetical populations with higher prevalence ratios of asthma, the added value of the FEV1:FVC ratio became less apparent.

CONCLUSION

Respiratory symptoms, especially wheezing, reported by children had good discriminating ability for asthma and could be adopted for opportunistic screening in the primary care settings.