β2-Adrenergic receptor promoter haplotype influences the severity of acute viral respiratory tract infection during infancy: a prospective cohort study.

Background: Despite the significant interest in β2-Adrenergic receptor (ADRB2) polymorphisms related to asthma, whether ADRB2 genetic variants are similarly associated with acute respiratory tract infections have not been studied. We hypothesized that genetic variants in ADRB2 associated with a response to asthma therapy during an asthma exacerbation were also associated with severity of acute respiratory tract infections.

Methods: To test this hypothesis, we genotyped 5 common polymorphisms in the promoter region and coding block of the ADRB2 gene (loci -2387, -2274, -1343, +46, and +79) from 374 Caucasian and African American term infants who were enrolled at the time of acute respiratory illness over four respiratory viral seasons.

Respiratory Severity Score Separates Upper Versus Lower Respiratory Tract Infections and Predicts Measures of Disease Severity.

A respiratory severity score (RSS) describing acute respiratory illness (ARI) severity would be useful for research and clinical purposes. A total of 630 term infants presenting with ARI had their RSS measured. RSS was higher in those with lower respiratory tract infection (LRTI) compared with those with upper respiratory infection (URI; LRTI 6.

Objectives, design and enrollment results from the Infant Susceptibility to Pulmonary Infections and Asthma Following RSV Exposure Study (INSPIRE).

Background: Respiratory syncytial virus (RSV) lower respiratory tract infection (LRI) during infancy has been consistently associated with an increased risk of childhood asthma. In addition, evidence supports that this relationship is causal. However, the mechanisms through which RSV contributes to asthma development are not understood.

Gastroesophageal Reflux Disease Increases Infant Acute Respiratory Illness Severity, but not Childhood Asthma.

It is unknown whether gastroesophageal reflux disease (GERD) during infancy affects infant bronchiolitis severity or childhood asthma inception. Four hundred thirty-two infants presenting with acute respiratory illness due to bronchiolitis or upper respiratory infection were studied. The primary exposure was the parental report of a previous GERD diagnosis.

Increased healthcare resource utilization for acute respiratory illness among Latino infants.

Objective: To examine healthcare resource utilization for acute respiratory illness in Latino infants compared with other racial/ethnic groups.

Study Design: We studied 674 term-born, previously healthy infants brought in for an unscheduled healthcare visit for an acute respiratory illness. The predictor variable was infant race/ethnicity, and the primary outcome was healthcare resource utilization, adjusted for age and disease severity.

Viral etiologies of infant bronchiolitis, croup and upper respiratory illness during 4 consecutive years.

Background: Prospective data on viral etiology and clinical characteristics of bronchiolitis and upper respiratory illness (URI) in infants are limited.

Methods: This prospective cohort enrolled previously healthy term infants during inpatient or outpatient visits for acute URI or bronchiolitis during September to May 2004 to 2008. Illness severity was determined using an ordinal bronchiolitis severity score.

Host and viral factors associated with severity of human rhinovirus-associated infant respiratory tract illness.

Background: Risk factors for severe human rhinovirus (HRV)-associated infant illness are unknown.

Objectives: We sought to examine the role of HRV infection in infant respiratory tract illness and assess viral and host risk factors for HRV-associated disease severity.

Methods: We used a prospective cohort of term, previously healthy infants enrolled during an inpatient or outpatient visit for acute upper or lower respiratory tract illness during the fall-spring months of 2004-2008.

Fetal nicotine exposure increases airway responsiveness and alters airway wall composition in young lambs.

To test the hypotheses that fetal nicotine exposure alters airway wall composition and enhances the airway response to inhaled methacholine (MCh), lambs were exposed during the last fetal trimester to (1) a low dose (LN) (n=13, 0.5mg/kg/d (maternal weight) of free base nicotine, (2) a moderate dose (MN) (n=10, 1.5mg/kg/d) or (3) saline (n=14).

Assessment of severity measures for acute asthma outcomes: a first step in developing an asthma clinical prediction rule.

Objective: As a first step in the development of an asthma prediction rule, our primary objective was to assess the association of 8 candidate predictor variables with 2 clinically relevant asthma outcomes.

Methods: Among a cohort of 125 adults hospitalized with an asthma exacerbation, we examined models to identify clinical variables associated with length of stay (LOS) and clinically significant asthma exacerbations within 3 months after hospitalization (3-month exacerbation). Eight candidate predictor variables were chosen, including age, sex, race, pulsus paradoxus, prior endotracheal intubation for asthma, hospitalization within 5 years for asthma, and 2 chronic asthma severity scores.

Changes in urinary dinor dihydro F(2)-isoprostane metabolite concentrations, a marker of oxidative stress, during and following asthma exacerbations.

To investigate changes in oxidant stress during and following acute asthma exacerbations, this study measured 2,3-dinor-5,6-dihydro-15-F(2t)-IsoP (F(2)-IsoP-M), the major urinary metabolite of 15-F(2t)-IsoP, in eight asthmatic adults, during and following an asthma hospitalization. F(2)-IsoP-M concentrations at admission and follow-up were significantly higher than discharge (admission median: 4.12 ng/Cr mg, range 1.

Clinical measures associated with FEV1 in persons with asthma requiring hospital admission.

Objective: We sought to determine the association of select clinical measures of asthma severity with percent predicted forced expiratory volume in one-second (%FEV1).

Methods: We studied a prospective cohort of adult subjects (N = 129) with asthma exacerbations requiring hospital admission. Clinical data was acquired, including medical and social history, symptoms, vital signs, physical assessment, and spirometry.

Prenatal nicotine exposure transiently alters the lung mechanical response to hypoxia in young lambs.

To test the hypothesis that fetal nicotine exposure alters the lung mechanical response to hypoxia (10% O(2)) 10 lambs were exposed during the last fetal trimester to a low dose nicotine (LN) and 10 to a moderate dose (MN) (maternal dose 0.5 and 1.5mg/(kgday) free base, respectively).

The relationship of rhinovirus-associated asthma hospitalizations with inhaled corticosteroids and smoking.

Background: Although rhinovirus (RV) respiratory infections trigger asthma exacerbations, the etiologic association between this virus and severe exacerbations, as well as the clinical characteristics of adults at risk for RV-associated asthma that necessitates hospitalization, have not been established.

Methods: During 1999-2003, we conducted a cohort study of 101 adults prospectively enrolled at hospital admission for an asthma exacerbation. Patient characteristics and frequencies of RV in nasal specimens were analyzed, by reverse-transcription polymerase chain reaction (RT-PCR), at asthma-related hospital admission and at a 3-month convalescent follow-up visit.