Lung function, airway remodeling, and inflammation in infants: outcome at 8 years.

BACKGROUND: Associations between early deficits of lung function, infant airway disease, and outcome at school age in symptomatic infants are still unclear. OBJECTIVE: To report follow-up data on a unique cohort of children investigated invasively in infancy to determine predictive value of airway disease for school-aged respiratory outcomes. METHODS: Fifty-three infants previously studied using bronchoscopy and airway conductance were approached at 8 years of age. Symptoms, lung volumes, and airway responsiveness were reassessed. Data on lifetime purchase of asthma medication were obtained. Lung function was compared with that of 63 healthy nonasthmatic children. RESULTS: Forty-seven children were reevaluated. Physician-diagnosed asthma was present in 39 children (83%). Twenty-five children (53%) had current and 14 children (30%) had past asthma. No pathologic feature in infancy correlated with any outcome parameter. As expected, study children had significantly reduced lung function and increased airway responsiveness compared with healthy controls, and very early symptoms were risk factors for reduced lung function. Current asthma was associated with reduced infant lung function and parental asthma. Reduced lung function in infancy was associated with purchase of inhaled corticosteroids when 6 to 8 and 0 to 8 years of age. CONCLUSION: The lack of predictive value of any pathologic measure in infancy, reported here for the first time to our knowledge, demonstrates that pathologic processes determining the inception of asthma, which are as yet undescribed, are different from the eosinophilic inflammation associated with ongoing disease.

Assessing direct and indirect airway hyperresponsiveness in children using impulse oscillometry.

BACKGROUND: Airway hyperresponsiveness (AHR) is a hallmark of asthma but its assessment is usually restricted to older children who are capable of performing the maneuvers involved in spirometry. In younger children, a feasible option to perform the lung function measurement is impulse oscillometry (IOS), which requires less cooperation. OBJECTIVE: To evaluate whether assessment of AHR by IOS could differentiate children with various obstructive symptoms from one another. METHODS: One hundred twenty-one children (median age 6.0 years, range 3.7-8.1 years) were examined: 31 with probable asthma characterized by current troublesome lung symptoms, 61 with a history of early wheezing disorder (recurrent wheezing ≤24 months of age), 15 with a history of bronchopulmonary dysplasia, and 14 healthy controls. Indirect AHR was assessed by exercise and mannitol challenge tests, and direct AHR was assessed with methacholine using IOS. AHR to exercise was defined as an increase of at least 40% in respiratory resistance at 5 Hz. In the mannitol and methacholine challenges, the dose causing an increase of 40% in respiratory resistance at 5 Hz was calculated. RESULTS: AHR to exercise was good at differentiating children with current troublesome lung symptoms from those in the other groups (P < .001). AHR to methacholine separated children with current troublesome lung symptoms, early wheezing disorder, and bronchopulmonary dysplasia from the controls (P < .001), whereas the mannitol test did not distinguish among the study groups (P = .209). CONCLUSION: The methacholine and exercise challenge tests with IOS identify children with probable asthma characterized by troublesome lung symptoms and therefore may represent a practical aid in the evaluation of AHR in young children.

Breast-fed infants and their later cardiovascular health: a prospective study from birth to age 32 years.

The aim of the present study was to evaluate the impact of infant breast-feeding on cardiovascular risk in young adults. This unique study group involved 158 subjects (eighty-two females) originally collected prospectively at birth in 1975 and followed up to the age of 32 years. Frequent visits during the first year guaranteed the knowledge of the precise duration of breast-feeding. All infants received at least some breast milk. Participants were assessed for both individual cardiovascular risk factors (blood pressure, plasma lipids, homeostatic model assessment of insulin resistance and waist circumference) and the general clinical risk of cardiovascular events by calculating the Framingham risk score (FRS) and the metabolic syndrome criteria score (NCEP-ATPIII; National Cholesterol Education Program's Adult Treatment Panel III). Data on lifestyle factors were carefully collected. Linear regression analyses revealed that the effect of the duration of breast-feeding was not relevant (0·02 decrease in the FRS per one additional breast-feeding month; 95 % CI - 0·19, 0·09). Similarly, the effect of breast-feeding was minor on all of the individual cardiovascular risk factors. We used sex, physical activity, dietary fat and vitamin C, smoking and alcohol consumption as covariates. Again, logistic regression analyses detected no significant impact of the duration of breast-feeding on the risk of the metabolic syndrome according to the NCEP-ATPIII (OR 0·95, 95 % CI 0·8, 1·1). The strongest independent predictor for later CVD risk was male sex. In conclusion, in this prospectively followed cohort of young adults born at term and at weight appropriate for gestational age, the duration of breast-feeding did not have an impact on the accumulation of cardiovascular risk factors.

Very low birth weight and respiratory outcome: association between airway inflammation and hyperresponsiveness.

BACKGROUND: The respiratory outcomes after preterm birth have changed, and it is unclear whether increased airway hyperresponsiveness (AHR) later in childhood is associated with airway inflammation. OBJECTIVE: To investigate the association between AHR and fractional exhaled nitric oxide (FeNO), including the alveolar concentration of nitric oxide, in school-age children with very low birth weight (VLBW). METHODS: Twenty-nine children with VLBW, 33 children with a history of early wheeze, and 60 healthy controls underwent a FeNO measurement and bronchial challenge test with histamine. Atopy was assessed with skin prick tests. RESULTS: Children with VLBW had well-preserved baseline lung function but significantly increased AHR, expressed as the dose response slope (P < .001). Geometric mean FeNO levels were similar between VLBW children and healthy controls, and a history of bronchopulmonary dysplasia had no effect. In the VLBW and early wheeze groups, AHR was associated with FeNO (r = 0.47, P = .01, and r = 0.43, P = .013, respectively), but in a stratified analysis, this association was significant only in atopic individuals. By using the multiple flow FeNO technique, the bronchial nitric oxide flux rather than alveolar nitric oxide concentrations were associated with AHR in both children with early wheeze and VLBW. CONCLUSION: We conclude that in VLBW children AHR is related to FeNO but only in atopic individuals. Similar to children with early wheeze, this association is dependent on bronchial flux rather than alveolar nitric oxide concentration. It is likely that AHR is modified by atopic inflammation rather than by inflammatory process due to prematurity.

Lung function, airway remodelling and inflammation in symptomatic infants: outcome at 3 years.

BACKGROUND: Relationships between early deficits of lung function, infant airway pathology and outcome in symptomatic infants are unclear. A study was undertaken to determine the associations between early lung function, airway histology and inflammation in symptomatic infants with the continuance of respiratory symptoms, lung function and subsequent use of inhaled asthma medication at the age of 3 years. METHODS: 53 children who underwent lung function measurements and bronchoscopy following referral to a specialist children's hospital for recurrent lower respiratory symptoms at a mean age of 1 year were followed up at 3 years of age. Assessments were made of respiratory symptoms during the previous year, lung function by oscillometry and atopy by skin prick testing. Individual data on the purchase of asthma medications were obtained from the Social Insurance Institution for the 12 months preceding the follow-up visit. RESULTS: 50 children (94%) were re-evaluated, of whom 40 had ongoing airway symptoms. 11/39 (28%) who underwent successful oscillometry had reduced lung function, 31/50 (62%) used inhaled corticosteroids (ICS) regularly and 12/50 (24%) used ICS intermittently. Abnormal lung function at infancy was associated with ongoing airway symptoms (p<0.001) and with the purchase of ICS (p=0.009) and ß agonists (p=0.002). Reticular basement membrane thickness in infancy and the numbers of mucosal mast cells, but not eosinophils, correlated significantly with the amount of ICS purchased at 3 years (p=0.003 and p=0.018, respectively). CONCLUSIONS: Reduced lung function, thickening of the reticular basement membrane and increased density of mucosal mast cells in infancy are associated with respiratory morbidity and treatment needs at age 3 years in this highly selected group of children.

Pulmonary autoimmunity as a feature of autoimmune polyendocrine syndrome type 1 and identification of KCNRG as a bronchial autoantigen.

Patients with autoimmune polyendocrine syndrome type 1 (APS-1) suffer from multiple organ-specific autoimmunity with autoantibodies against target tissue-specific autoantigens. Endocrine and nonendocrine organs such as skin, hair follicles, and liver are targeted by the immune system. Despite sporadic observations of pulmonary symptoms among APS-1 patients, an autoimmune mechanism for pulmonary involvement has not been elucidated. We report here on a subset of APS-1 patients with respiratory symptoms. Eight patients with pulmonary involvement were identified. Severe airway obstruction was found in 4 patients, leading to death in 2. Immunoscreening of a cDNA library using serum samples from a patient with APS-1 and obstructive respiratory symptoms identified a putative potassium channel regulator (KCNRG) as a pulmonary autoantigen. Reactivity to recombinant KCNRG was assessed in 110 APS-1 patients by using immunoprecipitation. Autoantibodies to KCNRG were present in 7 of the 8 patients with respiratory symptoms, but in only 1 of 102 APS-1 patients without respiratory symptoms. Expression of KCNRG messenger RNA and protein was found to be predominantly restricted to the epithelial cells of terminal bronchioles. Autoantibodies to KCNRG, a protein mainly expressed in bronchial epithelium, are strongly associated with pulmonary involvement in APS-1. These findings may facilitate the recognition, diagnosis, characterization, and understanding of the pulmonary manifestations of APS-1.

Longitudinal follow-up of bronchial inflammation, respiratory symptoms, and pulmonary function in adolescents after repair of esophageal atresia with tracheoesophageal fistula.

OBJECTIVE: To characterize symptoms, pulmonary function tests (PFT) and bronchial responsiveness (BR) in adolescents after repaired esophageal atresia with tracheoesophageal fistula and correlate these with endobronchial biopsy findings. STUDY DESIGN: After a primary operation, 31 patients underwent endoscopies and bronchoscopies at the age of <3, 3 to 7, and >7 years. A questionnaire on respiratory and esophageal symptoms was sent to patients at a mean age of 13.7 years (range, 9.7-19.4). The questionnaire was completed by 27 of 31 patients (87%), and 25 of the 31 patients (81%) underwent clinical examination and pulmonary functioning tests. Endobronchial biopsies were analyzed for reticular basement membrane (RBM) thickness and inflammatory cells. RESULTS: The prevalence of current respiratory and esophageal symptoms was 41% and 44%, respectively. "Doctor-diagnosed asthma" was present in 22% of patients. A restrictive and obstructive spirometric defect was observed in 32% and 30% of patients, respectively. Increased bronchial responsiveness, detected in 24% of patients, was weakly associated with current respiratory symptoms and low forced vital capacity. Mean exhaled nitric oxide was within predicted range. RBM thickness increased slightly with age, whereas inflammatory cell counts varied from normal to moderate, with intraindividual variation. CONCLUSION: Inflammation of the airways in adolescents with a history of tracheoesophageal fistula, even in the presence of atopy, does not lead, in most cases, to the type of chronic inflammation and RBM changes seen in asthma.

Patients with cartilage-hair hypoplasia have an increased risk for bronchiectasis.

OBJECTIVE: To assess the prevalence, predictors, and course of bronchiectasis in patients with cartilage-hair hypoplasia. STUDY DESIGN: Patients who had undergone high-resolution computed tomography of the lungs or bronchography were included in the study. Hospital records were coorelated for clinical features, respiratory symptoms, and laboratory variables. Imaging studies were correlated for changes suggestive of bronchiectasis and findings correlated with clinical and immunological measurements. RESULTS: The study included 15 patients (5 male; median height Z-score, -7.7) aged from 2 to 39 years (median, 10 years). Cell-mediated immunity was impaired in 79% of the subjects, and humoral immunity was impaired in 71% of the subjects. 8 patients (52%) had bronchiectasis, diagnosed by means of high-resolution computed tomography (n = 6) or bronchography (n = 2). The findings ranged from localized mild dilatation of the airways to severe bronchiectasis with saccular airway dilatation. Bronchiectasis progressed during follow-up in 2 patients. Patients with bronchiectasis tended to have more severe growth failure and more often had defective humoral immunity than the general cartilage-hair hypoplasia population. CONCLUSION: Patients with cartilage-hair hypoplasia are at risk of the development of bronchiectasis.

Human rhinovirus in bronchial epithelium of infants with recurrent respiratory symptoms.

BACKGROUND: Human rhinoviruses (HRVs) are a common cause of upper respiratory tract infections. There is growing evidence that HRVs are also important in lower respiratory tract infections and often induce asthma exacerbations. OBJECTIVE: We evaluated the presence of HRV in the lower respiratory tract by obtaining bronchial biopsies from infants with recurrent asthmalike respiratory symptoms. METHODS: A total of 201 steroid-naive infants age 3 to 26 months with recurrent respiratory symptoms for at least 4 weeks within the preceding 2 months were studied for lung function using body plethysmography. Bronchoscopy was performed in 68 children, and bronchial biopsies were available from 59 infants for HRV detection with in situ hybridization. RESULTS: Human rhinovirus was detected in 21 of 47 (45%) specimens. Abnormal lung function (decreased airways conductance) was found in 18 of 21 (86%) HRV(+) infants and in 15 of 26 (58%) HRV(-) infants (P = .037). Occurrence of a respiratory infection in the 6 weeks preceding bronchoscopy correlated with HRV positivity (P = .036). CONCLUSION: Human rhinovirus is frequently found in the lower airways in infants with recurrent respiratory symptoms, and the majority of these HRV(+) infants also showed increased airway resistance. CLINICAL IMPLICATIONS: Human rhinovirus is a common pathogen causing upper and lower respiratory symptoms. Follow-up of these infants will reveal whether the presence of HRV in the bronchial biopsy and abnormal lung function with recurrent respiratory symptoms predicts subsequent asthma.

IgA antibodies, TGF-beta1 and -beta2, and soluble CD14 in the colostrum and development of atopy by age 4.

Specific defense factors in breast milk together with length of breast-feeding and genetic predisposition may modulate the development of allergy. We studied whether IgA, soluble CD14 (sCD14), or transforming growth factor (TGF)-beta in colostrum could affect the development of atopy in children up to age 4. From a cohort of 4676, we selected four groups of children with either long or short exclusive breast-feeding (>3.5 or <0.5 mo); these groups further differed in the presence or absence of atopic heredity. In colostrum from mothers, we measured total IgA, IgA antibodies to cow's milk (CM) and casein, sCD14, and TGF-beta1 and -beta2. The children were divided into three groups: those with no atopic symptoms or IgE, those with allergic symptoms, and those with both outcomes. Mothers of infants later showing atopic symptoms or, in addition, having IgE sensitization (verified atopy) had a lower concentration of IgA casein antibodies in their colostrum than did mothers of infants with no indication of atopy at age 4. Low concentration of IgA casein antibodies was a significant risk for verified atopy. sCD14 levels were lower in colostrum of mothers with infants developing atopic symptoms and IgE sensitization than of those of infants with no atopy. Specific IgA antibodies to CM antigens and sCD14 in colostrum significantly associated with the appearance of both symptomatic and verified atopy by age 4.

Airway remodeling and inflammation in symptomatic infants with reversible airflow obstruction.

RATIONALE: We hypothesized that the epithelial reticular basement membrane (RBM) thickening and eosinophilic inflammation characteristic of asthma would be present in symptomatic infants with reversible airflow obstruction. METHODS: RBM thickness and numbers of inflammatory cells were determined in ultrathin sections of endobronchial biopsies obtained from 53 infants during clinical bronchoscopy for severe wheeze and/or cough. Group A: 16 infants with a median age of 12 months (range 3.4-26 months), with decreased specific airway conductance (sGaw) and bronchodilator reversibility; Group B: 22 infants with a median age of 12.4 months (5.1-25.9 months), with decreased sGaw but without bronchodilator reversibility; and Group C: 15 infants with a median age of 11.5 months (3.4-24.3 months) with normal sGaw. Additional comparisons were made with the following groups. Group D: 17 children, median age 10.3 years (6-16 years), with difficult asthma; Group E: 10 pediatric control subjects without asthma, median age 10 years (6-16 years); and Group F: nine adult normal, healthy control subjects, median age 27 years (21-42 years). MAIN RESULTS: There were no significant differences in RBM thickness or inflammatory cell number between the infant groups. RBM thickness was similar in the infants and Groups E and F. However, the RBM in all infant groups (Group A: median 4.3 microm [range 2.8-9.2 microm]; Group B: median 4.15 microm [range 2.7-5.8 microm]; Group C: median 3.8 microm [range 2.7-5.5 microm]) was significantly less thick than that in the older children with asthma (Group D: median 8.3 microm [range 5.3-12.7 microm]; p < 0.001). CONCLUSION: RBM thickening and the eosinophilic inflammation characteristic of asthma in older children and adults are not present in symptomatic infants with reversible airflow obstruction, even in the presence of atopy.