A familial predisposition in bronchial hyperresponsiveness among patients with allergic rhinitis

Transcriptional regulation on the gene expression signature in combined allergic rhinitis and asthma syndrome

AIM

This study was intended to evaluate transcriptional regulation of gene expression signatures in combined allergic rhinitis and asthma syndrome (CARAS).

MATERIALS & METHODS

The blood samples of three patients with CARAS, three patients with allergic rhinitis and three normal controls were obtained. The cuffdiff, miRDeep2 and DEGseq were used to quantify the expression of genes and miRNAs, respectively. And p-value < 0.01 and false discovery rate < 0.001 were considered as significant differences of genes and miRNAs, respectively. Gene ontology and the Kyoto Encyclopedia of Genes and Genomes were used to analyze the biological function. And the cut-off value for significance was p < 0.05.

RESULTS

SLC14A1, SNCA, TNS1, KAT2B and PARP1 were regulated by hsa-miR-93-5p, hsa-miR-92a-3p and hsa-miR-21-5p. Additionally, phagosome (p = 0.00627769839083361) was the only significantly enriched signal pathway involving HLA-DOA, TUBB2A and MRC2.

CONCLUSION

Disordered expression of genes under the regulation of miRNAs may play an important role in CARAS.

Evaluation of the eosinophil-to-lymphocyte ratio in pediatric patients with allergic rhinitis

BACKGROUND

Allergic rhinitis is a type 1 hypersensitivity reaction of the nasal mucosa, the primary mediator of which is immunoglobulin E. Allergic rhinitis occurs in children and adolescents.

OBJECTIVE

This study examined the relationship between allergies and the eosinophil-to-lymphocyte ratio in children with allergic rhinitis with a positive skin-prick test.

STUDY DESIGN

This study was planned and performed as a case-control study.

METHODS

There were 695 patients who presented to our clinic who were enrolled in the study. Only group 4 fit the criteria for allergic rhinitis. Group 1 (nonsensitized asymptomatic [control group]), group 2 (nonsensitized symptomatic), group 3 (sensitized asymptomatic), and group 4 (sensitized symptomatic). The patients' allergy symptoms and skin test results were assessed and compared. The eosinophil-to-lymphocyte ratio for each patient was calculated. The eosinophil and lymphocyte counts and the eosinophil-to-lymphocyte ratio were calculated for each group.

RESULTS

The eosinophil-to-lymphocyte ratio and eosinophil counts in groups 3 and 4 were significantly higher (p < 0.001 and p < 0.001, respectively) than those in groups 1 and 2. The lymphocyte counts in groups 3 and 4 were significantly lower (p = 0.046) than those of groups 1 and 2.

CONCLUSIONS

The eosinophil-to-lymphocyte ratio may be used in conjunction with skin-prick testing in pediatric patients with allergic rhinitis. This parameter is inexpensive to measure and easy to use and calculate.

Exercise-induced bronchospasm related to different phenotypes of rhinitis without asthma in primary schoolchildren: the French Six Cities Study

BACKGROUND

Exercise-induced bronchospasm (EIB) is frequent among asthmatic children. However, opinions differ on the relation between EIB and rhinitis in the absence of asthma.

OBJECTIVES

We assessed the relationship between EIB and various phenotypes of rhinitis according to asthmatic status at the general population level in the Six Cities Study.

METHODS

Of 7781 schoolchildren with a mean age of 10 years underwent an EIB test and skin prick test to assess allergic sensitization. Their parents completed a standardized questionnaire recording asthma-like symptoms and past-year rhinoconjunctivitis, ever hay fever (EHF), and a score for allergic rhinitis (SFAR) ≥7 as a marker of 'past-year allergic rhinitis'. Exercise-induced bronchospasm was defined as a fall in peak expiratory flow rate ≥15% after exercise.

RESULTS

Of the 6813 schoolchildren retained for analysis, 227 (3.33%) experienced EIB after exercise. Odds ratios [95% confidence intervals] between EIB and allergic rhinitis phenotypes in the absence of asthma were 1.56 [0.92-2.63] for EHF, 1.97 [1.16-3.35] for past-year rhinoconjunctivitis, and 1.84 [1.16-2.91] for a SFAR ≥7. Results were unchanged after adjustment for confounders. Multiple correspondence analysis showed that EIB, although related to asthma, constitutes a separate entity. Exercise-induced bronchospasm was not significantly related to familial history of asthma.

CONCLUSION

In our large population-based sample of children, different phenotypes of atopic rhinitis were associated with EIB, independently of asthma. Exercise-induced bronchospasm, although related to asthma, seems to constitute a separate entity.

CLINICAL RELEVANCE

In this large (6813) sample of 10-year children drawn from the general population, EIB is associated with rhinitis phenotypes in the absence of asthma. Furthermore, it constitutes an entity independent from asthma and is not related to a familial history of asthma. Thus, investigating these symptoms could be important in this disease, as a specific nasal treatment might improve EIB in these children.

Impact of rhinitis on asthma severity in school-age children

BACKGROUND

In a population-based sample of school-age children, we investigated factors associated with rhinitis, and differences between allergic and nonallergic rhinitis. Amongst children with asthma, we explored the association between rhinitis and asthma severity.

METHODS

Children participating in a birth cohort study (n = 906) were reviewed at age 8 years. Asthma was defined as at least two of the following three features: physician-diagnosed asthma, currently using asthma medication and current wheeze. We measured lung function (plethysmography and spirometry) and airway hyper-reactivity (AHR; methacholine challenge).

RESULTS

In the analysis adjusted for the presence of asthma, children with rhinitis had significantly higher AHR (P = 0.001). Maternal smoking and absence of breastfeeding were stronger predictors of nonallergic rhinitis, whereas current wheeze and eczema were stronger predictors of allergic rhinitis. Amongst asthmatics (n = 159), when compared to 76 children without rhinitis, those with rhinitis (n = 83) were 2.89-fold (95% CI 1.41-5.91) more likely to experience frequent attacks of wheezing, 3.44-fold (1.19-9.94) more likely to experience severe attacks of wheezing limiting speech, 10.14-fold (1.27-81.21) more likely to have frequent visits to their doctor because of asthma and nine-fold (1.11-72.83) more likely to miss school. Reported use of intranasal corticosteroids resulted in a numerically small, but consistent reduction in risk, rendering the associations between rhinitis and asthma severity nonsignificant.

CONCLUSION

We observed differences in risk factors and severity between allergic and nonallergic rhinitis. In children with asthma, rhinitis had adverse impact on asthma severity. The use of intranasal corticosteroids resulted in a small, but consistent reduction in the risk.

Can an airway challenge test predict respiratory diseases? A population-based international study

BACKGROUND

Evidence on the longitudinal association of airway responsiveness with respiratory diseases is scarce. The best indicator of responsiveness is still undetermined.

OBJECTIVE

We investigated the association of airway responsiveness with the incidence of asthma, chronic obstructive pulmonary disease (COPD), and allergic rhinitis.

METHODS

We studied 3851 subjects who underwent spirometry and methacholine challenge tests both at baseline (1991-1993), when they were 20 to 44 years old, and at follow-up (1999-2002) in the European Community Respiratory Health Survey. Airway responsiveness was defined based on the methacholine dose-response slope on both occasions. Incidence rate ratios for the association of airway responsiveness with disease occurrence were computed by using Poisson regression.

RESULTS

With respect to reference (slope of the fourth quintile or greater), subjects with the greatest degree of airway responsiveness (slope less than the first quintile) showed the greatest risk of developing asthma, COPD, and allergic rhinitis (incidence rate ratios of 10.82, 5.53, and 4.84, respectively; all P < .01). A low slope predicted disease occurrence, even in subjects who did not reach a 20% decrease in FEV1 at the cumulative dose of 1 mg of methacholine (PD20 >1 mg). A decrease in slope over time was an independent predictor of disease risk.

CONCLUSION

Airway responsiveness predicted new-onset asthma, COPD, and allergic rhinitis. Our study supports the use of a continuous noncensored indicator of airway responsiveness, such as the slope of the methacholine dose-response curve, in clinical practice and research because it showed clear advantages over PD20.

Relationship between atopy and bronchial hyperresponsiveness

Both atopy and bronchial hyperresponsiveness (BHR) are characteristic features of asthma. They are also found among non-asthmatic subjects, including allergic rhinitis patients and the general population. Atopy and BHR in asthma are closely related. Atopy induces airway inflammation as an IgE response to a specific allergen, which causes or amplifies BHR. Moreover, significant evidence of the close relationship between atopy and BHR has been found in non-asthmatic subjects. In this article, we discuss the relationship between atopy and BHR in the general population, asthmatic subjects, and those with allergic rhinitis. This should widen our understanding of the pathophysiology of atopy and BHR.

Airway hyperresponsiveness and quality of life in Western red cedar asthmatics removed from exposure

Objectives

Most western red cedar asthmatics (WRCA) continue to have symptoms even after removal from exposure. Consequently, health-related quality of life (HRQL) is often impaired. The objective of this study was to evaluate the relationship between two measures of AHR and HRQL scores in those with WRCA.

Methods

HRQL was determined by the short form 36 (SF-36) in 46 male, non-smoking individuals with WRCA removed from exposure to western red cedar, on average, 15 years earlier. The relationships between the SF-36 total score and its eight domains with 2 indices from methacholine-stimulated airway hyperresponsiveness (the provocative concentration of methacholine causing a 20% fall in FEV₁ [PC₂₀] and bronchial reactivity index [BRI]) were analyzed by the Pearson correlation and multiple linear regression.

Results

PC₂₀ was significantly correlated with the SF-36 total score and its two domains of bodily pain and general health (r = 0.34, 0.40, 0.40, p = 0.023, 0.006, 0.006, respectively). BRI was significantly correlated with bodily pain and general health (r = −0.35, −0.42, p = 0.017, 0.004, respectively); correlations remain significant after adjusting for age, ethnicity, years since diagnosis, years since last exposure and use of inhaled corticosteroid. BRI and other measures of airway responsiveness were not associated with inhaled corticosteroids use.

Conclusions

In Western red cedar asthmatics removed from exposure, measures of airway responsiveness are associated with HRQL.

A case of viral myocarditis presenting with acute asthma attack

Acute viral myocarditis is one of the causes of heart failure. Cardiac asthma is commonly observed in elderly patients with left heart failure. If the pulmonary manifestations are prominent it can mask the involvement of heart. We report a young case of viral myocarditis mimicking acute asthma attack.

CASE PRESENTATION

A 27-year-old young man with a history of asthma presented to the pulmonary department of our hospital with dyspnea, left sided chest pain, cough, wheezing. Asthma was diagnosed and treated, however his respiratory complaints have persisted. Laboratory evaluations revealed that elevated cardiac enzymes, Echocardiogram showed global hypokinesia in the left ventricle and a decrease of ejection fraction. We concluded that viral myocarditis can present itself like an acute asthma attack.

Bronchial hyperresponsiveness to methacholine and adenosine monophosphate and the degree of atopy in children with allergic rhinitis

BACKGROUND

nonasthmatic patients with allergic rhinitis often have bronchial hyperresponsiveness (BHR). Not only the presence but also the degree of atopy are important factors in BHR of patients with asthma. BHR is commonly evaluated by bronchial challenges using direct or indirect stimuli.

OBJECTIVES

to assess BHR to methacholine (direct) and to adenosine monophosphate (AMP) (indirect) in children with allergic rhinitis and to compare their relationships with the degree of atopy.

METHODS

methacholine and AMP challenges were performed in 88 children with allergic rhinitis, and a provocative concentration causing a 20% decrease in forced expiratory volume in 1 second (PC(20)) was calculated for each challenge. The degree of atopy was measured using serum total IgE levels, number of positive skin prick test results, and atopic scores (sum of graded wheal size).

RESULTS

BHR to methacholine (PC(20) <8 mg/mL) and to AMP (PC(20) <200 mg/mL) was observed in 22 (25%) and 30 (34%) patients, respectively. No association was found between BHR to methacholine and any atopy parameter. In contrast, serum total IgE levels and atopic scores were higher in the group with BHR to AMP than in the group without BHR to AMP. Furthermore, a significant association was found between the degree of these 2 parameters and BHR to AMP (score for trend, P < .001 and P = .03, respectively).

CONCLUSIONS

both BHR to methacholine and BHR to AMP were detected in a significant proportion of children with allergic rhinitis. The degree of atopy seems to be an important factor in BHR to AMP but not in BHR to methacholine.

Risk for asthma in offspring of asthmatic mothers versus fathers: a meta-analysis

BACKGROUND

Many human epidemiologic studies demonstrate that maternal asthma confers greater risk of asthma to offspring than does paternal disease. However, a handful have shown the opposite. Given this disparity, a meta-analysis is necessary to determine the veracity and magnitude of the "maternal effect."

METHODOLOGY/PRINCIPAL FINDINGS

We screened the medical literature from 1966 to 2009 and performed a meta-analysis to compare the effect of maternal asthma vs. paternal asthma on offspring asthma susceptibility. Aggregating data from 33 studies, the odds ratio for asthma in children of asthmatic mothers compared with non-asthmatic mothers was significantly increased at 3.04 (95% confidence interval: 2.59-3.56). The corresponding odds ratio for asthma in children of asthmatic fathers was increased at 2.44 (2.14-2.79). When comparing the odds ratios, maternal asthma conferred greater risk of disease than did paternal asthma (3.04 vs. 2.44, p = 0.037). When analyzing the studies in which asthma was diagnosed by a physician the odds ratios were attenuated and no significant differences were observed (2.85 vs. 2.48, N = 18, p = 0.37). Similarly, no significant differences were observed between maternal and paternal odds ratios when analyzing the studies in which the patient population was 5 years or older (3.15 vs. 2.60, p = 0.14). However, in all cases the trend remained the same, that maternal asthma was a greater risk factor for asthma than paternal.

CONCLUSIONS/SIGNIFICANCE

The results show that maternal asthma increases offspring disease risk to a greater extent than paternal disease.

Interpretation of the "positive" methacholine challenge

BACKGROUND

A methacholine challenge may be used in confirming the diagnosis of asthma, occupational asthma, or reactive airways dysfunction syndrome (RADS) through identification of bronchial hyperreactivity (BHR). While sensitivity of the test in diagnosing clinically significant asthma is excellent, specificity of the test is poor. Since there are many conditions which have been associated with BHR, a positive test must be interpreted cautiously.

METHODS

This paper reviews potential causes of a positive methacholine challenge other than asthma or RADS which have been reported in the medical literature.

RESULTS

Factors which may be associated with a positive methacholine test include test methodology, normal variation of BHR in the general population, and numerous medical conditions.

CONCLUSIONS

In cases of inhalation exposure evaluations, alternative explanations must be considered when determining whether a causal association exists between the exposure and a positive methacholine test result.

Bronchial hyperresponsiveness in young children with allergic rhinitis and its risk factors

BACKGROUND

Subjects with allergic rhinitis but no clinical evidence of asthma have greater bronchial hyperresponsiveness (BHR), and several factors have been implicated as its determinants. However, studies in young children are lacking. The aims of this study were to evaluate the prevalence of BHR in young children with allergic rhinitis and to investigate its risk factors.

METHODS

Methacholine bronchial challenges were performed in 4- to 6-year-old nonasthmatic children with allergic rhinitis (n = 83) and in healthy nonatopic controls (n = 32), using a modified auscultation method. The end-point was defined as the appearance of wheezing and/or oxygen desaturation. Subjects were considered to have BHR when they had end-point concentrations of methacholine <or=8 mg/mL. Clinical and laboratory data in allergic rhinitis patients and a history of allergic diseases in their parents were collected.

RESULTS

BHR was observed in 27 subjects with allergic rhinitis (32.5%) and three controls (9.4%). Among subjects with allergic rhinitis, serum total IgE, the number and pattern of skin-prick test responses, blood eosinophil markers, and parental history of allergic rhinitis and atopic dermatitis were not different between the BHR(+) and BHR(-) groups, whereas the persistent type of rhinitis and parental history of asthma were more frequent in the BHR(+) group than in the BHR(-) group. These associations remained significant in a multivariable logistic regression.

CONCLUSIONS

Young children with allergic rhinitis alone showed an increased prevalence of BHR. Both persistent type of rhinitis and parental history of asthma were significant and independent risk factors for BHR in these children.

The current status of asthma in Korea

A systematic review of English and Korean articles published between 1990 and 2004 and a search of database and various online resources was conducted to determine the prevalences, mortality rates, socioeconomic burden, quality of life, and treatment pattern of asthma in Korean adults and children. Asthma morbidity and mortality in Korea are steadily increasing. The prevalence of asthma in Korea is estimated to be 3.9% and its severity is often underestimated by both physicians and patients. Mortality resulting from chronic lower respiratory diseases including asthma increased from 12.9 to 22.6 deaths per 100,000 of the population between 1992 and 2002. Disease severity, level of control, and symptom state were all found to negatively impact the quality of life of asthmatics. Although international and Korean asthma management guidelines are available, familiarity with and implementation of these guidelines by primary care physicians remain poor.

[Allergic rhinitis and bronchial hyperreactivity]

BACKGROUND

Bronchial hyperreactivity (BHR) is a characteristic of bronchial asthma. Patients with allergic rhinitis who do not report symptoms of bronchial asthma on spirometry show BHR, which could indicate the presence of subclinical inflammation of the lower respiratory airway. The aim of this study was to investigate whether the patients diagnosed with allergic rhinitis in our unit without symptoms of bronchial asthma had bronchial hyperreactivity and to determine which allergens caused these symptoms in our patients.

METHODS AND RESULTS

We performed a retrospective, observational study of patients diagnosed with allergic rhinitis in our Allergy Unit between August 2000 and December 2001. The patients' medical records were reviewed and data on the following were gathered: demographic information, age, sex, rhinitis symptoms (perennial or seasonal), conjunctivitis, atopic dermatitis, bronchitis, sensitization (specific IgE, skin tests, nasal challenge tests), total IgE levels, spirometry performed through stress test (positive with a decrease of FEV1 > 15 % with stress or an increase of FEV1 of 12 % after bronchodilation) and family history of allergic disease. A total of 135 medical records of patients with allergic rhinitis were reviewed. Of these, 68 did not report symptoms of bronchial asthma (35 men and 33 women aged between 4 and 18 years). Most of our patients (50/68) reported perennial asthma and were sensitized to mites (44/68). In 14/68 spirometry was not performed at diagnosis. Stress test was positive in 13/54 (24 %). All patients who showed bronchial hyperreactivity were sensitized to mites and only one of these reported seasonal rhinitis.

CONCLUSIONS

According to the latest guidelines on the treatment and control of allergic rhinitis --The Allergic Rhinitis and its Impact on Asthma Workshop Report-- bronchial asthma and allergic rhinitis are distinct manifestations of a single airway and of the same disease. In view of our results, we recommend systematic evaluation of bronchial hyperreactivity in the study protocol of allergic rhinitis in patients who do not report symptoms of bronchial asthma.

Bronchial hyperresponsiveness in children with atopic rhinitis: a 7-year follow-up

BACKGROUND

A high prevalence of bronchial hyperresponsiveness (BHR) was found in atopic subjects with rhinitis. Those subjects may be at higher risk for developing bronchial asthma. We evaluated, in a 7-year follow-up, BHR and atopy in a homogeneous population of nonasthmatic children with allergic rhinitis (AR), and their role in asthma development.

METHODS

Twenty-eight children (6-15 years) with AR were studied. At enrollment (T(0)), skin tests, total serum IgE assay, peak expiratory flow (PEF) monitoring and methacholine (Mch) bronchial challenge were performed. BHR was computed as the Mch dose causing a 20% forced expiratory volume (FEV)(1) fall (PD(20)FEV(1)) and as dose-response slope (D(RS)). Subjects were reassessed after 7 years (T(1)) using the same criteria.

RESULTS

At T(0), 13 children (46%), showing a PD(20)FEV(1) <1526 microg of Mch, had BHR (Mch+), although PEF variability (PEFv) was within normal limits. None of the children with negative methacholine test developed bronchial asthma after 7 years. Of the 13 Mch+, only two reported asthma symptoms after 7 years. No significant change was seen in the other parameters of atopy considered.

CONCLUSION

Children with allergic rhinitis present a high prevalence of BHR. Nevertheless, their PEFv is normal and the rate of asthma development low.

Non-specific bronchial hyper-responsiveness in children with allergic rhinitis: relationship with the atopic status

An increased prevalence of bronchial hyper-responsiveness (BHR) has been demonstrated in children from a general population, and in non-asthmatic adults with allergic rhinitis. Thus, also children with allergic rhinitis are expected to be at higher risk of BHR. We evaluated the prevalence of BHR in a sample of non-asthmatic children with allergic rhinitis by means of the methacholine (Mch) bronchial challenge, and by monitorizing the airway patency using the daily peak expiratory flow variability (PEFv). Fifty-one children (ranged 6-15 years of age) with allergic rhinitis, ascertained by skin prick test to inhalant allergens, underwent a 14-day peak expiratory flow monitoring, and a Mch bronchial provocation challenge. Thirty healthy children matched for age, and sex served as control group. Thirty-one children in the rhinitis group (61%), and six (20%) in the control group were Mch+ (Mch provocative dose causing a 20% fall of forced expiratory volume in 1 s respect to baseline <2250 microg, equivalent to 11.50 micromol). In rhinitic children the PEFv did not significantly differ between Mch+ and Mch- subjects, but the total serum immunoglobulin E (IgE) were higher among Mch+. The persistent form of rhinitis was significantly associated to Mch positivity. Non-asthmatic children with allergic rhinitis displayed a high prevalence of BHR. The BHR was significantly associated with persistent rhinitis and with higher total IgE levels. Nevertheless, the spontaneous changes in airway patency, as expressed by PEFv, were within normal limits both in Mch+ and Mch- children.

Absence of association of peripheral blood eosinophilia or increased eosinophil cationic protein with bronchial hyperresponsiveness during asthma remission

BACKGROUND

The mechanisms responsible for persistent bronchial hyperresponsiveness (BHR) in adolescents with long-term asthma remission are poorly understood.

OBJECTIVE

To determine whether BHR in adolescents with asthma remission is associated with peripheral blood eosinophilia, increased serum levels of eosinophil cationic protein (ECP), or both findings.

METHODS

We classified 51 adolescents with long-term asthma remission (neither asthma-related symptoms nor medication during the previous 2 years) into 28 BHR-positive patients (methacholine PC20 [provocative concentration causing a 20% decrease in forced expiratory volume in 1 second] <18 mg/mL) and 23 BHR-negative patients. The peripheral blood eosinophil counts and serum ECP concentrations were compared between these 2 groups. Twenty-eight patients with symptomatic asthma (symptomatic group), matched for methacholine PC20 level with study subjects in the BHR-positive remission group, and 28 healthy adolescents (control group) were also studied.

RESULTS

No significant differences in the peripheral blood eosinophil counts (262.1 +/- 117.0/microL vs 253.9 +/- 165.0/microL) and the serum ECP levels (15.6 +/- 10.0 microg/L vs 15.8 +/- 11.9 microg/L) were found between the BHR-positive and BHR-negative remission groups, respectively. The BHR-positive remission group differed from the symptomatic group (372.9 +/- 190.3/microL, P < 0.05; 26.6 +/- 11.3 microg/L, P < 0.01) in both blood indices but resembled the control group (214.6 +/- 118.6/microL and 12.1 +/- 4.8 microg/L; both, no significant difference).

CONCLUSIONS

BHR in adolescents with long-term asthma remission is not associated with peripheral blood eosinophilia or an increase in serum ECP concentration. This finding suggests that the mechanism underlying BHR in this clinical setting may differ from that in symptomatic asthma.

Bronchial hyperresponsiveness in adolescents with long-term asthma remission: importance of a Family history of bronchial hyperresponsiveness

BACKGROUND

The mechanisms responsible for bronchial hyperresponsiveness (BHR) in symptomatic asthma include genetic predisposition and airway inflammation, but the causes of BHR in adolescents with asthma remission are poorly understood. It has been shown that BHR in adolescents with asthma remission was not reduced by prolonged treatment with inhaled corticosteroids, in contrast to the BHR of symptomatic asthma.

OBJECTIVE

The aim of this study was to investigate whether family history of BHR may contribute to the persistence of BHR in asthma remission during adolescence.

METHODS

One hundred twenty-six adolescents with long-term asthma remission (neither symptoms nor any medication used during the previous 2 years) and their parents underwent a methacholine inhalation test. The provocative concentration of methacholine causing a 20% fall in FEV(1) (PC(20)) and the bronchial responsiveness (BR) index were calculated for each individual.

RESULTS

Sixty-nine adolescents (54.8%) were found to have persisting BHR (PC(20) < 18 mg/mL). The frequency of BHR and the BR index were significantly higher in parents (n = 138) of the BHR-persisting group (28.3% and 1.150 +/- 0.103, respectively [mean +/- 1 SD]) than in parents (n = 114) of BHR-nonpersisting group (16.7% [p = 0.030] and 1.124 +/- 0.088 [p = 0.029], respectively). Furthermore, adolescents (n = 56) with at least one BHR-positive parent were found to have a higher frequency of BHR (66.1% vs 45.7%, p = 0.023) and a higher BR index (1.244 +/- 0.090 vs 1.204 +/- 0.082, p = 0.011) than adolescents (n = 70) with non-BHR parents.

CONCLUSION

Our results suggest that adolescents in asthma remission are more likely to have BHR when there is a family history of BHR. Further studies are needed to examine the possible involvement of genetic factors in the BHR of adolescents in asthma remission.

The importance of maximal airway response to methacholine in the prediction of wheezing development in patients with cough-variant asthma

BACKGROUND

A significant proportion of patients diagnosed with cough-variant asthma eventually manifest classic asthma signs, such as wheezing and dyspnea. The aim of this study was to investigate whether the degree of airway hypersensitivity and/or the level of maximal airway response can predict the development of wheezing in subjects with cough-variant asthma.

METHODS

At study initiation, a high-dose methacholine inhalation test was performed to measure provocative concentration causing a 20% fall (PC20) in forced expiratory volume in 1 s (FEV1) and maximal airway response. Each person was evaluated regularly every 3 months for 4 years and also on the occasion of wheezing being perceived for the first time.

RESULTS

Of the 48 patients available in the follow-up period, 21 (Group 1) developed clinical wheezing, while 27 (Group 2) did not. There was no significant difference in PC20 levels between the two groups. The level of maximal airway response, however, was significantly higher in Group 1 than in Group 2. The score test for trend revealed a significant association between the future development of wheezing and the level of maximal airway response (P = 0.007), but not the level of methacholine PC20 (P = 0.423).

CONCLUSIONS

The level of maximal airway response, rather than the degree of airway hypersensitivity, may be an important risk factor for the future development of classic asthma in patients with cough-variant asthma.

The importance of maximal airway response to methacholine in the prediction of asthma development in patients with allergic rhinitis

BACKGROUND

Allergic rhinitis is a known predictor and correlate of asthma incidence. However, it is not clear which patients with allergic rhinitis are at greater risk of the development of asthma.

OBJECTIVE

The aim of this study was to investigate whether airway hypersensitivity and/or increased maximal response on the dose-response curve to methacholine would predict the development of asthma in subjects with allergic rhinitis.

METHODS

One hundred and forty-one children with allergic rhinitis were prospectively studied for 7 years. At the initiation of the study, bronchial provocation test with methacholine using a stepwise increasing concentration technique was performed to measure PC(20) (provocative concentration causing a 20% fall in FEV(1)) and maximal response. Each subject was evaluated at least every 6 months and details of asthmatic symptoms or signs experienced during the intervening period were taken.

RESULTS

Twenty of 122 subjects available for the follow-up developed asthma. Nine (19.6%) of 46 hypersensitive (PC(20) < 18 mg/mL) subjects developed asthma, compared with 11 (14.5%) of 76 normosensitive subjects (P = 0.462). Eight (32%) of 25 subjects without maximal response plateau developed asthma, compared with 12 (12.4%) of 97 subjects with maximal response plateau (P = 0.018). Score test for trend revealed a significant association between the level of maximal response (P = 0.007), but not the degree of methacholine PC(20) (P = 0.123), and the future development of asthma.

CONCLUSION

An increased maximal airway response to methacholine is shown to be a better predictor for the future development of asthma in patients with allergic rhinitis, than airway hypersensitivity to methacholine.

Association of beta2-adrenoreceptor polymorphisms with nocturnal cough among atopic subjects but not with atopy and nonspecific bronchial hyperresponsiveness

BACKGROUND

The reports from in vitro studies that beta(2)-adre-nergic receptor (B2AR) polymorphisms are associated with agonist-promoted downregulation have evoked considerable research interest for the roles of these polymorphisms to the pathogenesis of asthma.

OBJECTIVE

We sought to evaluate the association between asthma phenotypes and B2AR polymorphisms at 2 sites (Arg16 --> Gly16 and Gln27 --> Glu27) in the general population.

METHODS

Four hundred forty unrelated Korean adults were randomly selected, and asthma phenotypes were determined with a questionnaire, immunoassay, skin prick testing, and methacholine bronchial provocation testing. Genotypes of B2AR polymorphisms were determined with PCR-based methods.

RESULTS

No significant association was found between B2AR alleles and haplotypes and total IgE levels, skin test responses to aeroallergens, and bronchial responsiveness to methacholine. Among the atopic subjects, however, numbers of both Arg16 alleles and Arg16-Gln27 haplotypes were negatively associated with nocturnal cough, and in contrast, Gly16-Gln27 was positively associated with it.

CONCLUSION

B2AR polymorphisms may play an important role in the expression of nocturnal cough in atopic subjects but not in the expression of atopy and bronchial hyperresponsiveness in a general population.

[Risk factors for bronchial asthma in patients with rhinitis]

OBJECTIVES

To identify risk factors for bronchial asthma in a large sample of patients with rhinitis.

PATIENTS AND METHODS

One thousand seven hundred sixty patients with rhinitis treated at the respiratory medicine out-patient service of Hospital Universitario Virgen de Rocío in Seville (Spain) in 1997 and 1998 were studied. Six hundred forty-one (36.4%) had isolated rhinitis and 1,119 (63.6%) had rhinitis and bronchial asthma. The following variables were analyzed for both groups: 1) age, 2) sex, 3) clinical diagnosis, 4) age of onset of symptoms, 5) a family history of asthma and/or atopy, 6) housing conditions, 7) smoking, 8) a history of skin allergy, 9) recurrent episodes of respiratory infection with wheezing during early childhood, 10) a diagnosis of nasosinus polyposis, 11) atopy and sensitivity (pollens and/or household allergens), 12) peripheral blood eosinophil count.

RESULTS

The variables that best differentiated the group with rhinitis from the group with both rhinitis and asthma were age, family history of asthma and/or atopy, exposure to household humidity or damp, a history of skin allergy, recurrent episodes of respiratory infection with wheezing in early childhood, atopy, sensitivity to household allergens and peripheral blood eosinophil count. The probability of correctly classifying patients in the appropriate group using this model was 69.7%. Among atopic patients, the best predictive variables were the same, with the exception of household humidity/damp. The probability of correct classification using this model was 69.7%.

CONCLUSIONS

Patients with rhinitis have risk factors for bronchial asthma. As many such patients as possible should be identified so that long-term follow-up can take place and strategies to prevent bronchial asthma can be implemented.

Bronchial responsiveness to methacholine is increased in citrus red mite (Panonychus citri)-sensitive children without asthmatic symptoms

BACKGROUND

A recent investigation has suggested that citrus red mite (Panonychus citri, CRM) is a common sensitizing allergen among children living around citrus farms.

OBJECTIVE

A cross-sectional survey was performed to evaluate the bronchial responsiveness to methacholine in CRM-sensitive children without asthmatic symptoms.

SUBJECTS AND METHODS

A total of 375 children living around citrus farms were enrolled in this study. There were 201 boys and 174 girls with a mean age of 12.5 (range 7-16) years. Each subject was evaluated by a questionnaire, a skin prick test with 13 common inhalant allergens including CRM, and a methacholine bronchial provocation test (MBPT).

RESULTS

Positive rate of MBPT (PC20-methacholine < 25 mg/mL) was higher in atopic rhinitic and atopic control children than in nonatopic rhinitic and nonatopic control subjects (41.3% and 33.3% vs 17.2% and 15.4%, respectively, both P < 0.05). Slope of dose-response curve (DRS, %/mg/mL) was higher in atopic rhinitic children than in nonatopic rhinitic, atopic control and nonatopic control subjects (14.3 +/- 0.87 vs 9.4 +/- 0.72, 10.0 +/- 1.37 and 9.2 +/- 1.51, P < 0.05, respectively). Both the positive rate of MBPT and the DRS were increased in children with positive skin response to CRM than in those without sensitization (48.2% vs 22.9%, P = 0.0001; 15.6 +/- 1.26 vs 10.2 +/- 0.65, P = 0.0001).

CONCLUSION

Bronchial responsiveness is increased in citrus red mite-sensitive children even if they have no asthmatic symptoms.

Reactive airways dysfunction syndrome (RADS): guidelines for diagnosis and treatment and insight into likely prognosis

Reactive airways dysfunction syndrome (RADS) is defined as the sudden onset of asthma following a high level exposure to a corrosive gas, vapor, or fume. This variant of occupational asthma continues to generate controversy regarding the criteria for its diagnosis. There is also some disagreement as to the likely prognosis with this disorder. Currently, the diagnosis requires the assumption of normal premorbid pulmonary physiology and absence of bronchial hyperreactivity. Criteria for the diagnosis of RADS are discussed with a proposal for both major and minor criteria to increase the confidence of an accurate diagnosis. The pathology of RADS involves a primarily lymphocytic inflammatory response with some evidence of subepithelial thickening and fibrosis. Most patients with this condition who survive the short-term exposure to a toxicant recover completely without significant clinical or physiologic sequelae. The issue of low-level RADs remains controversial and problematic as a tenable diagnosis, and will require further careful investigation to evaluate the premise that chronic, low-level toxicants are capable of leading to such a condition. More likely, most of the cases which have been reported represent preexisting asthma and/or expressions of an atopic predisposition.