Biomedical subjects

Young Yull Koh

Publications and source records attributed to Young Yull Koh.

At least 19 recordsLinked to original sources

PubMed2006

Bronchial responsiveness to methacholine and adenosine 5'-monophosphate in preschool children with bronchopulmonary dysplasia.

Bronchial hyperresponsiveness (BHR) is a characteristic feature of asthma, but it is also frequently present in children and adults with chronic obstructive lung diseases. Bronchopulmonary dysplasia (BPD) is a chronic lung disease, most commonly developing after mechanical ventilation and oxygen therapy in premature infants. BHR is usually measured by bronchial challenges, using direct or indirect stimuli. The aim of this study was to evaluate BHR to direct and indirect stimuli in young children with BPD. Methacholine and adenosine 5'-monophosphate (AMP) bronchial challenges were performed on preschool children with BPD (n = 19), using a modified auscultation method. The endpoint was defined as the appearance of wheezing and/or oxygen desaturation. The results obtained were then compared with those of asthmatic (n = 25) and control (n = 23) preschool children. A positive response to methacholine (endpoint concentration, < or = 8 mg/ml) was observed in 89.5% (17/19) of patients with BPD, but a positive response to AMP (endpoint concentration, < or = 200 mg/ml) was observed only in 21.1% (4/19). All patients with asthma responded positively to methacholine, and most (23/25, 92.0%) of them also responded positively to AMP. The majority of controls were unresponsive to both challenges. BHR to methacholine is a frequent finding in preschool-age survivors of BPD, but is usually not accompanied by BHR to AMP. This suggests that most patients with BPD do not have the inflammatory airway response which is characteristic of asthmatic patients.

Adenosine Monophosphate↗

PubMed2006

Bronchial responsiveness to methacholine and adenosine 5'-monophosphate (AMP) in young children with post-infectious bronchiolitis obliterans.

AIM: Bronchial hyperresponsiveness (BHR) is a characteristic feature of asthma, but it is also frequently demonstrated by children and adults with chronic obstructive lung diseases. BHR is usually measured by bronchial challenges using direct or indirect stimuli. The aim of this study was to compare these two types of bronchial challenge in young children with post-infectious bronchiolitis obliterans (BO). METHODS: Methacholine and adenosine 5'-monophosphate (AMP) bronchial challenges were performed on preschool children with post-infectious BO (n=18), those with asthma (n=23) and in controls (n=20), using a modified auscultation method. The endpoint was defined as the appearance of wheezing and/or oxygen desaturation. RESULTS: A positive response to methacholine (an endpoint concentration < or = 8 mg/ml) was observed in 88.9% (16/18) of the patients with post-infectious BO, but a positive response to AMP (an endpoint concentration < or = 200 mg/ml) was observed in only 22.2% (4/18). All patients with asthma responded positively to methacholine, and most (21/23, 91.3%) of them also responded positively to AMP. The majority of the controls were insensitive to both challenges. CONCLUSION: BHR to methacholine is a frequent, but by no means universal, finding in young children with post-infectious BO, but is usually not accompanied by BHR to AMP.

Adenosine Monophosphate↗

PubMed2006

Increased levels of BAL cysteinyl leukotrienesinacute [corrected] RSV bronchiolitis.

BACKGROUND: Cysteinyl leukotrienes (CysLTs), including LTC4, LTD4 and LTE4, are pivotal mediators in the pathophysiology of asthma. AIM: To determine whether CysLT levels are increased in the lower airways of children with respiratory syncytial virus (RSV) bronchiolitis, as they are in asthmatic children, and to investigate a possible heterogeneity in CysLT levels in children with RSV bronchiolitis. METHODS: Bronchoalveolar lavage (BAL) fluids were obtained from children with acute RSV bronchiolitis (n = 20), from children with acute asthma who had no identifiable virus infection (n = 16) and from control subjects (n = 14). BAL cell counts and differentials were determined, and the concentrations of CysLTs were measured by ELISA. RESULTS: CysLT levels in the asthma (70.6 +/- 52.7 pg/ml, p < 0.001) and bronchiolitis groups (21.9 +/- 23.3 pg/ml, p < 0.05) were significantly higher than in the control group (8.7 +/- 5.2 pg/ml). Among bronchiolitis subjects, the eosinophil-positive subgroup (n = 6) showed significantly higher CysLT levels (49.0 +/- 26.7 pg/ml, p = 0.001) than the control group, but this was not observed in the eosinophil-negative subgroup (n = 14, 10.3 +/- 6.3 pg/ml, p = 0.47). CONCLUSION: CysLT levels are increased in the lower airways during RSV bronchiolitis, although their intensities are lower than those in acute asthma. Among bronchiolitis subjects, high CysLT producers could be distinguished from low CysLT producers by the presence of eosinophilia in BAL fluids, suggesting a pathophysiological heterogeneity in RSV bronchiolitis.

Acute Disease↗

PubMed2006

Percentage fall in FVC at the provocative concentration of methacholine causing a 20% fall in FEV1 in symptomatic asthma and clinical remission during adolescence.

BACKGROUND: Many children with asthma go into long-term clinical remission at adolescence, but bronchial hyperresponsiveness (BHR) persists in approximately one half of these subjects. BHR is usually assessed by measuring the provocative concentration of methacholine causing a 20% fall in FEV1 (PC20). The percentage fall in FVC at the PC20 (deltaFVC) has been suggested to be a more useful index of disease severity in asthma than PC20. STUDY OBJECTIVE: The aim of this study was to determine whether deltaFVC is higher in adolescents with symptomatic asthma than in those with clinical remission. PATIENTS AND METHODS: Forty adolescents with symptomatic asthma and 80 adolescents with asthma remission underwent methacholine challenge testing. DeltaFVC and PC20 were measured on the methacholine dose-response curve. RESULTS: The mean (95% confidence interval [CI]) deltaFVC (15.5% [95% CI, 14.1 to 16.9%]) in the symptomatic group (n = 40) was significantly higher (p = 0.017) than that (12.8% [95% CI, 11.5 to 14.1%]) in the BHR-positive (PC20 < 16 mg/mL) remission group (n = 44) or that (11.5% [95% CI, 10.2 to 12.8%]) of the BHR-negative remission group (n = 36), with no difference between the two latter groups (p = 0.581). No significant correlation was found between deltaFVC and PC20 in the symptomatic group (r = -0.156, p = 0.336) or in the whole remission group (r = -0.187, p = 0.097). CONCLUSIONS: Adolescents with symptomatic asthma had a higher deltaFVC than those with clinical remission, irrespective of the presence of BHR in the latter group. This finding suggests that deltaFVC may serve as an adjunct marker for differentiating between asthma persistence and remission during adolescence.

Adolescent↗

PubMed2005

Coincidence of atopy and its profile (monosensitization/polysensitization) between sibling pairs.

BACKGROUND: Results of epidemiologic studies have shown that childhood atopy is probably a hereditary disorder. In the atopic population, some individuals are sensitized to only 1 class of allergens (monosensitized), whereas others are sensitized to more than 1 class of allergens (polysensitized). OBJECTIVE: To investigate whether atopy and its profile (monosensitization/polysensitization) tend to coincide in sibling pairs. METHODS: We evaluated sensitization to 5 classes of aeroallergens (house dust mites, animal danders, pollens, molds, and cockroach) using skin prick testing in 564 children with symptoms suggestive of allergic diseases (index children) and their paired siblings. RESULTS: The frequency of sibling atopy was highest (56.8%) for polysensitized index children (n=222), intermediate (45.4%) for monosensitized index children (n=196), and lowest (30.8%) for nonsensitized index children (n=146). The proportion of polysensitization among atopic siblings was significantly higher for polysensitized (47.6%) than for monosensitized (32.6%) index children. Polysensitized index children were found to more frequently have polysensitized siblings (27.0%) than were monosensitized index children (14.8%), with an odds ratio of 2.13 (95% confidence interval, 1.30-3.49), whereas the likelihood of having a monosensitized sibling was similar for monosensitized and polysensitized index children. CONCLUSION: These data suggest a coincidence of atopy and its profile in terms of monosensitization and polysensitization in sibling pairs, although the relative importance of genetic and environmental influences requires further study.

Allergens↗

PubMed2005

Bronchial responsiveness and serum eosinophil cationic protein levels in preschool children with recurrent wheezing.

BACKGROUND: Bronchial hyperresponsiveness is a universally recognized phenomenon of asthma, and increased levels of eosinophil cationic protein (ECP) have been identified in the serum of patients with asthma. OBJECTIVES: To investigate whether enhanced bronchial responsiveness and elevated serum ECP levels are associated with recurrent wheezing in preschool children and to examine the possible relationship between these 2 variables. METHODS: We recruited 130 children aged 4 to 6 years: 59 with at least 3 episodes of wheezing in the previous year (current wheezers), 38 with a documented history of wheezing before 3 years of age but no subsequent wheezing episodes (past wheezers), and 33 who had never experienced wheezing (nonwheezers). The children underwent methacholine bronchial provocation tests using a modified auscultation method and blood sampling for the measurement of ECP levels. RESULTS: Current wheezers showed greater bronchial responsiveness than past wheezers and nonwheezers, as demonstrated by lower provocation concentrations that caused audible wheeze and lower provocation concentrations that caused a decline in oxygen saturation of at least 5% from baseline. Likewise, current wheezers had higher serum ECP levels than the other 2 groups. Among current wheezers, ECP levels showed a significant negative correlation with provocation concentrations that caused oxygen desaturation and a marginally significant correlation with provocation concentrations that caused audible wheeze. CONCLUSIONS: Enhanced bronchial responsiveness and elevated serum ECP levels are associated with recurrent wheezing in 4- to 6-year-old children. These results suggest that wheezing during preschool years may be phenotypically similar to wheezing in older children.

Asthma↗

PubMed2005

Peak expiratory flow variability and exercise responsiveness in methacholine-hyperresponsive adolescents with asthma remission.

The aim of this study was to investigate whether bronchial hyperresponsiveness in adolescents with long-term asthma remission is associated with increased peak expiratory flow (PEF) variability and/or increased bronchial response to exercise (BRE). Twenty-nine adolescents with asthma remission (neither symptoms nor any medication used during the previous two years), but with persistent methacholine hyperresponsiveness (PC20 < 18 mg/mL; remission group), 29 methacholine PC20-matched adolescents with symptomatic asthma (symptomatic group), and 20 healthy subjects (control group) were studied. Subjects recorded PEF twice daily for 14 days and PEF variability, expressed as amplitude % mean, was calculated. Subjects also underwent a standardized exercise challenge; BRE was defined as a maximal % fall in FEV1 within 30 min after exercise. The mean (+/- SD) PEF variations in the symptomatic group and in the remission group were 12.10 +/- 6.35% and 10.02 +/- 4.73%, respectively, which were significantly higher than that (5.94 +/- 2.44%) of the control group. On the other hand, the degree of BRE (7.36 +/- 3.85%) in the remission group was significantly lower than that (22.31 +/- 10.50%) of the symptomatic group, and similar to that (5.98 +/- 2.70%) of the control group. Methacholine hyperresponsiveness in asthma remission during adolescence is associated with increased PEF variability but not with increased BRE.

Adolescent↗

PubMed2005

Bronchoalveolar lavage eosinophil cationic protein and interleukin-8 levels in acute asthma and acute bronchiolitis.

OBJECTIVE: In this study, we measured the levels of eosinophil cationic protein (ECP) and interleukin (IL)-8 in bronchoalveolar lavage (BAL) fluid from patients with acute asthma and acute bronchiolitis, to determine any similarities or dissimilarities in the profiles of these biochemical markers in the two diseases. METHODS: BAL fluids were obtained from children with acute asthma (n=16), infants with acute bronchiolitis caused by respiratory syncytial virus (n=18), and control subjects (n=14). Children with asthma were selected to be free of viral infection. BAL cell counts and differentials were determined, and ECP and IL-8 levels were measured by radioimmunoassay and ELISA, respectively. RESULTS: ECP levels in BAL fluids were significantly higher in the asthma group than in the bronchiolitis (P<0.01) or control (P<0.0001) groups. However, IL-8 levels were significantly higher in the bronchiolitis group than in the asthma (P<0.01) or control (P<0.001) groups. IL-8 levels in the asthma group and ECP levels in the bronchiolitis group were similar to those of the control group. CONCLUSION: This difference in profiles of ECP and IL-8 in acute asthma and acute bronchiolitis, together with a different inflammatory cell pattern, suggests that the nature of the inflammatory process within the lower respiratory tract may be distinctive in these two diseases.

Acute Disease↗

PubMed2005

Clinical characteristics of chronic lung disease without preceding respiratory distress syndrome in preterm infants.

BACKGROUND: Recently, the incidence of atypical presentation of chronic lung disease (CLD) that develops in infants without a history of preceding respiratory distress syndrome (RDS) is increasing. Therefore, the clinical characteristics of CLD without RDS in comparison with CLD with RDS were assessed. METHODS: Prospective cohort analysis was done from 117 very low-birthweight infants who were born in Seoul National University Hospital and survived more than 36 weeks postmenstrual age (PMA). RESULTS: Of the 117 infants analyzed, CLD developed in 44 infants (38%). Among these 44 infants, CLD with RDS developed in 27 infants (23%) and CLD without RDS developed in 17 infants (15%). Each type of CLD was subgrouped according to the presence of chorioamnionitis (CA): RDS(+)CA(+) CLD (n = 8) and RDS(+)CA(-) CLD (n = 19); and RDS(-)CA(+) CLD (n = 12) and RDS(-)CA(-) CLD (n = 5). There were no significant differences in the demographic characteristics between CLD with RDS and CLD without RDS. Chorioamnionitis was significantly more common in CLD without RDS, while patent ductus arteriosus was more common in CLD with RDS. Although the severity of initial respiratory failure was not greater than that of CLD with RDS, CLD without RDS showed a gradually increasing chronic oxygen requirement pattern. Chronic oxygen requirement pattern showed that infants with RDS(+)CA(+)CLD required the highest concentrations of oxygen not only initially but also thereafter until the 28th day of life and 36 weeks PMA. CONCLUSIONS: Although CLD without RDS was still less common than CLD with RDS, it comprised over a third of all cases of CLD in our study. Clinical characteristics and chronic oxygen requirement pattern of CLD without RDS seems to be less severe than those of CLD with RDS. Our data suggest that CLD without RDS may be developed by causes other than initial acute lung injury. Chorioamnionitis may be one of antecedents of CLD without RDS.

Case-Control Studies↗

PubMed2005

Risk factors for the different types of chronic lung diseases of prematurity according to the preceding respiratory distress syndrome.

BACKGROUND: Recently, atypical chronic lung disease (CLD) of prematurity that develops in the absence of preceding respiratory distress syndrome (RDS) have been observed frequently. The specific risk factors for atypical CLD that are presumed to be different from those for classical CLD that develops following RDS were assessed. METHODS: Prospective cohort analysis was done from 115 very low-birthweight infants who were born in Seoul National University Hospital, Seoul, Korea, and survived more than 36 weeks postmenstrual age or 28 days of life. All subjects were classified into either a preceding RDS group (n = 35) or a non-RDS group (n = 80). Logistic regression analysis was done for the multivariate assessment of specific risk factors for CLD in both groups. RESULTS: The analysis showed that short gestational age (GA; relative risk [RR], 3.1 per 1 week decrement; 95% confidence intervals [CI], 2.7-3.4), of the male gender (RR, 9.8; CI, 0.9-112), and poor response to surfactant (RR, 14; CI, 1.2-156) were significant risk factors for CLD in the preceding RDS group. In the non-RDS group, chorioamnionitis was one of the significant risk factors for CLD (RR, 4.8; CI, 1.1-21) along with short GA and high mean airway pressure (MAP) during the first 3 days of life. CONCLUSION: Chorioamnionitis was a risk factor for atypical CLD in addition to short GA and high MAP during the early postnatal period, and poor response to surfactant was a risk factor for classical CLD in addition to short GA and being male. Therefore, CLD is considered to have type-specific risk factors.

Chorioamnionitis↗

PubMed2005

Maximal airway response to methacholine in cough-variant asthma: comparison with classic asthma and its relationship to peak expiratory flow variability.

BACKGROUND: In asthmatic subjects, not only airway sensitivity but maximal airway response are increased on the dose-response curve to methacholine, and peak expiratory flow (PEF) variability is closely related to airway hypersensitivity and maximal airway response. OBJECTIVE: The aims of this study were to compare the prevalence and the level of maximal response plateau between patients with cough-variant asthma (CVA) and those with classic asthma (CA), and to examine the relationship between airway hypersensitivity or maximal airway response and PEF variability in patients with CVA. METHODS: A high-dose methacholine inhalation test was performed on 83 patients with CVA and on 83 patients with CA matched for provocative concentration of methacholine causing a 20% fall in FEV1 (PC20). PEF was recorded in the morning and evening for 14 consecutive days in 78 CVA patients, and the amplitude percentage mean was used to express the diurnal PEF variation. RESULTS: Fifty-two CVA subjects (62.7%) but only 33 CA subjects (39.8%) showed a maximal response plateau. This difference was significant after correction by the Bonferroni method (corrected p = 0.024). Subjects in the CVA and CA groups showing a plateau had significantly different plateau levels (38.0 +/- 5.9% vs 42.9 +/- 3.9%, corrected p = 1.0 x 10(-4)). In patients with CVA, no significant relationship was found between PC20 and PEF variability. However, the absence of a maximal response plateau and a higher plateau level were associated with increased PEF variability. CONCLUSIONS: Maximal airway response may be an important confounder in the relationship between airway hypersensitivity and the clinical expression of asthma. The identification of a maximal response plateau and the level of this plateau in patients with CVA provide information relevant to PEF variability.

Age Factors↗

PubMed2005

Distributions of antibody titers to Mycoplasma pneumoniae in Korean children in 2000-2003.

The aim of study was to describe Mycoplasma pneumoniae epidemics in a hospital-based population. Special attention was paid to the relationship between antibody titer to M. pneumoniae and sex, age, and atopy. During the eight 6-month periods between January 2000 and December 2003, serum samples were obtained from 1,319 Korean children who presented with respiratory symptoms, and were examined for antibodies to M. pneumoniae using the indirect particle agglutination test. Geometric mean antibody titers peaked in the second half of 2000 and then decreased gradually, a second peak occurred in the second half of 2003. Likewise, the frequency of high antibody titers (> or =1:640) also peaked during these two periods. Antibody titers in children aged 0-3 yr were lower than in older children during both peak periods and for 2 yr after the first peak. Sex and atopy had no effect on antibody titers. During the years 2000-2003, geometric mean antibody titers and the frequencies of high antibody titers varied with time. These changes suggest a cyclic pattern of M. pneumoniae infection, with two epidemic peaks separated by 3 yr.

Adolescent↗

PubMed2004

Increase in cord blood soluble E-selectin and tracheal aspirate neutrophils at birth and the development of new bronchopulmonary dysplasia.

AIM: To test the hypothesis that preterm infants who develop new type of bronchopulmonary dysplasia BPD have higher cord blood sE-selectin levels and neutrophil counts in the tracheal aspirate at birth than those who do not. METHODS: The relationship between cord blood sE-selectin levels and neutrophil counts in the tracheal aspirate at birth and the development of BPD was examined in 30 preterm infants. Levels of sE-selectin and neutrophil counts were measured by specific immunoassay and by cytospin analysis. RESULTS: Median cord blood levels of sE-selectin and neutrophil counts in the tracheal aspirate at birth were higher in preterm infants who developed BPD than in those who did not (P<0.01 for each). These differences persisted significantly after adjusting for the effects of gestational age and the presence of histologic chorioamnionitis and patent ductus arteriosus PDA (P<0.01 for each). CONCLUSION: Fetal pulmonary inflammation, as measured by increased cord blood levels of sE-selectin and neutrophil counts in the tracheal aspirate at birth, may be a risk factor for the development of new BPD in preterm infants. These results support the hypothesis that the lung injury responsible for new BPD in preterm infants can begin in the prenatal period and could be associated with a fetal pulmonary inflammation.

Biomarkers↗

PubMed2004

Current treatment for primary ciliary dyskinesia conditions.

Primary ciliary dyskinesia (PCD) is a heterogeneous group of conditions characterised by ultrastructural defects of the cilia, which result in impaired mucociliary clearance. Although the incidence of PCD is low, early recognition and prompt management are important in order to prevent unnecessary morbidity, the progression of bronchiectasis and the deterioration of lung function. As the underlying defect in PCD cannot be corrected, the mainstay of therapy remains effective clearance of airway secretions and antibiotic therapy of respiratory tract infections. This paper highlights new developments in the field that have implications for the future management of PCD. These include beta-adrenergic agonists, arginine, uridine-5'-triphosphate, hypertonic saline and recombinant human DNase. It is to be hoped that these treatment modalities will have a therapeutic role in PCD.

Adrenergic beta-Agonists↗

PubMed2003

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.

Adolescent↗

PubMed2003

Bronchoalveolar lavage cytokine profiles in acute asthma and acute bronchiolitis.

BACKGROUND: The pathogenetic basis for the relationship between acute bronchiolitis and asthma has not yet been completely elucidated. OBJECTIVE: The aim of this study was to compare these 2 diseases in terms of their patterns of airway cytokine response (T(H)1 or T(H)2). METHODS: By using a bronchoalveolar lavage (BAL) technique, this study investigated the cytokine levels of BAL fluid in children with acute asthma who had no identifiable respiratory syncytial virus (RSV) infection (n = 18) and in infants with acute bronchiolitis caused by RSV (n = 22). Comparisons were made with normal control subjects (n = 14). IFN-gamma (T(H)1) and IL-4 and IL-5 (T(H)2) levels were measured in concentrated BAL fluids by means of ELISA. RESULTS: The IL-5 level (P <.001) and IL-5/IFN-gamma ratio (P <.001) were significantly increased in the asthmatic group with no identifiable RSV infection and in the RSV-induced bronchiolitis group compared with values in the control group. When infants in the bronchiolitis group were divided into eosinophil-positive and eosinophil-negative subgroups, the eosinophil-positive subgroup had significantly increased IL-5 levels (P <.001) and IL-5/IFN-gamma ratios (P <.01) compared with those in the control group, but similar cytokine responses were not induced in the eosinophil-negative subgroup. The percentage of BAL eosinophils correlated significantly with levels of BAL IL-5 in both the asthma group (r = 0.80, P =.000) and the bronchiolitis group (r = 0.82, P =.000). CONCLUSIONS: These findings suggest that a subgroup of the RSV-induced bronchiolitis group results in a T(H)2-type response, and this could provide a valuable framework to explain the link between RSV-induced bronchiolitis and asthma.

Acute Disease↗

PubMed2003

The development of asthma in patients with allergic rhinitis.

PURPOSE OF REVIEW: We will review data supporting the link between allergic rhinitis and asthma, examine recent progress made towards understanding the influence of allergic rhinitis on asthma regarding future development or progression of asthma, and discuss possible mechanisms through which this occurs and potential preventive measures. RECENT FINDINGS: Several recent reviews have concluded that a close relationship exists between allergic rhinitis and asthma. It has even been proposed that allergic rhinitis and asthma are manifestations of the same disease entity and that they represent a continuum of disease. Allergic rhinitis often precedes the onset of clinical asthma and is a risk factor for the development of asthma. Recognition of this relationship between allergic rhinitis and asthma is highlighted by the recent development of guidelines for the diagnosis and treatment of these disorders by the international Allergic Rhinitis and Its Impact on Asthma workshop. The mechanisms by which allergic rhinitis may be a risk factor for asthma are not entirely understood, although a few recent studies have addressed this question. Some clues in regard to the identification of subjects at risk of developing asthma have been provided by recent studies. Several recent reports support the belief that early introduction of immunotherapy in patients with allergic rhinitis reduces subsequent development of asthma, whereas it remains to be studied whether timely pharmacotherapy for allergic rhinitis may prevent the progression to asthma. SUMMARY: Because asthma is generally permanent at the time of diagnosis, it would be of great benefit to identify individuals at increased risk of developing asthma in order to provide a window of opportunity in which the progression to asthma could be prevented. As recognition and early treatment of allergic rhinitis could have important consequences in terms of reducing the prevalence and severity of asthma, there is a need to perform further clinical studies that address this issue.

Asthma↗

PubMed2003

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.

Adolescent↗