Circulating biomarkers of airflow limitation across the life span.

BACKGROUND: Airflow limitation is a hallmark of chronic obstructive pulmonary disease, which can develop through different lung function trajectories across the life span. There is a need for longitudinal studies aimed at identifying circulating biomarkers of airflow limitation across different stages of life. OBJECTIVES: This study sought to identify a signature of serum proteins associated with airflow limitation and evaluate their relation to lung function longitudinally in adults and children. METHODS: This study used data from 3 adult cohorts (TESAOD [Tucson Epidemiological Study of Airway Obstructive Disease], SAPALDIA [Swiss Cohort Study on Air Pollution and Lung and Heart Diseases in Adults], LSC [Lovelace Smoker Cohort]) and 1 birth cohort (TCRS [Tucson Children's Respiratory Study]) (N = 1940). In TESAOD, among 46 circulating proteins, we identified those associated with FEV1/forced vital capacity (FVC) percent (%) predicted levels and generated a score based on the sum of their z-scores. Cross-sectional analyses were used to test the score for association with concomitant lung function. Longitudinal analyses were used to test the score for association with subsequent lung function growth in childhood and decline in adult life. RESULTS: After false discovery rate adjustment, serum levels of 5 proteins (HP, carcinoembryonic antigen, ICAM1, CRP, TIMP1) were associated with percent predicted levels of FEV1/FVC and FEV1 in TESAOD. In cross-sectional multivariate analyses the 5-biomarker score was associated with FEV1 % predicted in all adult cohorts (meta-analyzed FEV1 decrease for 1-SD score increase: -2.9%; 95% CI: -3.9%, -1.9%; P = 2.4 × 10-16). In multivariate longitudinal analyses, the biomarker score at 6 years of age was inversely associated with FEV1 and FEV1/FVC levels attained by young adult life (P = .02 and .005, respectively). In adults, persistently high levels of the biomarker score were associated with subsequent accelerated decline of FEV1 and FEV1/FVC (P = .01 and .001). CONCLUSIONS: A signature of 5 circulating biomarkers of airflow limitation was associated with both impaired lung function growth in childhood and accelerated lung function decline in adult life, indicating that these proteins may be involved in multiple lung function trajectories leading to chronic obstructive pulmonary disease.

Single-Cell Profiling of Premature Neonate Airways Reveals a Continuum of Myeloid Differentiation.

Single-cell genomic technologies hold great potential to advance our understanding of lung development and disease. A major limitation lies in accessing intact cells from primary lung tissues for profiling human airway health. Sampling methods such as endotracheal aspiration that are compatible with clinical interventions could enable longitudinal studies, the enrollment of large cohorts, and the development of novel diagnostics. To explore single-cell RNA sequencing profiling of the cell types present at birth in the airway lumen of extremely premature neonates (<28 wk gestation), we isolated cells from endotracheal aspirates collected from intubated neonates within the first hour after birth. We generated data on 10 subjects, providing a rich view of airway luminal biology at a critical developmental period. Our results show that cells present in the airways of premature neonates primarily represent a continuum of myeloid differentiation, including fetal monocytes (25% of total), intermediate myeloid populations (48%), and macrophages (2.6%). Applying trajectory analysis to the myeloid populations, we identified two trajectories consistent with the developmental stages of interstitial and alveolar macrophages, as well as a third trajectory presenting an alternative pathway bridging the distinct macrophage precursors. The three trajectories share many dynamic genes (N = 5,451), but also have distinct transcriptional changes (259 alveolar-specific, 666 interstitial-specific, and 285 bridging-specific). Overall, our results define cells isolated within the so-called "golden hour of birth" in extremely premature neonate airways, representing complex lung biology, and can be used in studies of human development and disease.

Cytomegalovirus serology in young to mid-adult life and decline of lung function.

INTRODUCTION: Cytomegalovirus (CMV) seropositivity has been recently linked to severity and progression of asthma, cystic fibrosis, and chronic obstructive pulmonary disease (COPD). To date, no longitudinal study has addressed the relation of CMV serology to levels and decline of lung function in the general adult population. METHODS: We evaluated 403 participants from the Tucson Epidemiological Study of Airway Obstructive Disease (TESAOD) who at enrollment were aged 28-55 years and completed lung function tests. During follow-up, the 403 participants completed on average 7.2 lung function tests per subject for a total of 2908 observations over a mean period of 14.7 years. We tested CMV serology in serum samples from enrollment and categorized participants into low, medium, and high CMV serology based on tertiles. The relation of CMV serology at enrollment to lung function levels and decline during follow-up was tested in multivariate random coefficients models. RESULTS: After full adjustment, participants in the highest CMV serology tertile had faster declines of forced expiratory volume in 1 s (FEV1 ) and FEV1 /forced vital capacity (FVC) compared with subjects in the lowest tertile (by -7.9 ml/year 95% confidence interval [-13.9 ml/year, -1.93 ml/year], and by -0.13%/year [-0.23%/year, -0.026%/year], respectively). These CMV effects were additive with those of cigarette smoking. No associations were found between CMV serology and FVC, indicating specific effects of CMV seropositivity on airflow limitation. CONCLUSION: High CMV serology in young to mid-adult life may be linked to increased COPD risk through an accelerated decline of lung function.

Club cell secretory protein and lung function in children with cystic fibrosis.

BACKGROUND: Club cell secretory protein (CC16) exerts anti-inflammatory functions in lung disease. We sought to determine the relation of serum CC16 deficits and genetic variants that control serum CC16 to lung function among children with cystic fibrosis (CF). METHODS: We used longitudinal data from CF children (EPIC Study) with no positive cultures for Pseudomonas aeruginosa prior to enrollment. Circulating levels of CC16 and an inflammatory score (generated from CRP, SAA, calprotectin, G-CSF) were compared between participants with the lowest and highest FEV1 levels in adolescence (LLF and HLF groups, respectively; N = 130-per-group). Single nucleotide variants (SNVs) in the SCGB1A1, EHF-APIP loci were tested for association with circulating CC16 and with decline of FEV1 and FEV1/FVC% predicted levels between ages 7-16 using mixed models. RESULTS: Compared with the HLF group, the LLF group had lower levels of CC16 (geometric means: 8.2 vs 6.5 ng/ml, respectively; p = 0.0002) and higher levels of the normalized inflammatory score (-0.21 vs 0.21, p = 0.0007). Participants in the lowest CC16 and highest inflammation tertile had the highest odds for having LLF (p<0.0001 for comparison with participants in the highest CC16 and lowest inflammation tertile). Among seven SNVs associated with circulating CC16, the top SNV rs3741240 was associated with decline of FEV1/FVC and, marginally, FEV1 (p = 0.003 and 0.025, respectively; N = 611 participants, 20,801 lung function observations). CONCLUSIONS: Serum CC16 deficits are strongly associated with severity of CF lung disease and their effects are additive with systemic inflammation. The rs3741240 A allele is associated with low circulating CC16 and, possibly, accelerated lung function decline in CF.

High cytomegalovirus serology and subsequent COPD-related mortality: a longitudinal study.

BACKGROUND: Positive serology for cytomegalovirus (CMV) has been associated with all-cause mortality risk but its role in COPD mortality is unknown. The objective of the present study was to assess the relationship between CMV serology and COPD mortality. METHODS: We analysed data from 806 participants in the Tucson Epidemiological Study of Airway Obstructive Disease who, at enrolment, were aged 28-70 years and had completed lung function tests. We tested CMV serology in sera from enrolment and defined "high CMV serology" as being in the highest tertile. Vital status, date and cause of death were assessed through death certificates and/or linkage with the National Death Index up to January 2017. The association of CMV serology with all-cause and cause-specific mortality risk was tested in Cox models adjusted for age, sex, level of education, body mass index, smoking status and pack-years. RESULTS: High CMV serology was marginally associated with all-cause mortality (p=0.071) but the effect was inversely dependent on age, with the association being much stronger among participants <55 years than among participants ≥55 years at enrolment (p-value for CMV-by-age interaction <0.001). Compared with low CMV serology, high CMV serology was associated with mortality from COPD among all subjects (adjusted hazard ratio (HR) 2.38, 95% CI 1.11-5.08; p=0.025) and particularly in subjects <55 years old at enrolment (HR 5.40, 95% CI 1.73-16.9; p=0.004). Consistent with these results, high CMV serology also predicted mortality risk among subjects who already had airflow limitation at enrolment (HR 2.10, 95% CI 1.20-3.68; p=0.009). CONCLUSIONS: We report a strong relationship between CMV serology and the risk of dying from COPD, and thus identify a novel risk factor for COPD mortality.

CC16 Levels into Adult Life Are Associated with Nitrogen Dioxide Exposure at Birth.

Rationale: Lung function and growth are adversely associated with nitrogen dioxide (NO2) exposure. Lower levels of circulating club cell secretory protein (CC16) in childhood are also associated with subsequent decreased lung function. NO2 exposure may induce epithelial damage in lungs and alter club cell proliferation and morphology.Objectives: To determine if increased ambient NO2 levels at participants' home addresses in early life were associated with decreased levels of CC16 from age 6 to 32 years.Methods: Participants were enrolled at birth in the Tucson Children's Respiratory Study and had circulating CC16 measured at least once between age 6 and 32. Linear mixed models were used to determine the association between estimated ambient NO2 exposure at participants' home address at birth or age 6 with CC16 levels from age 6 to 32.Measurements and Main Results: NO2 exposures at birth or age 6 were available for 777 children with one or more CC16 measurement. We found a negative association between NO2 exposure and CC16 levels, with a 4.7% (95% confidence interval, -8.6 to -0.7) decrease in CC16 levels from age 6 to 32 per interquartile range increase in NO2 exposure (6.0 ppb) at the participants' birth address. We observed modification by race (p interaction = 0.04), with stronger associations among participants with at least one black parent (-29.6% [95% confidence interval, -42.9% to -13.2%] per interquartile range). NO2 at participant's age 6 address was not significantly associated with CC16 levels (-1.9%; 95% confidence interval, -6.3 to 2.6).Conclusions: Higher exposure to NO2 at birth is associated with persistently low levels of CC16 from 6 to 32 years.

Non-atopic rhinitis at age 6 is associated with subsequent development of asthma.

BACKGROUND: It has been postulated that the association between allergic rhinitis and asthma is attributable to the progressive clinical expression of respiratory inflammation during childhood. The role of non-allergic rhinitis in early life in relation to subsequent asthma has not been extensively explored. OBJECTIVE: We sought to determine whether rhinitis in early life was associated with risk of asthma development into adulthood, and whether this relationship is independent of allergic sensitization. METHODS: Participants were identified from the Tucson Children's Respiratory Study, a non-selected birth cohort. Allergy skin prick testing was performed at age 6 years using house dust mix, Bermuda, mesquite, olive, mulberry, careless weed, and Alternaria aeroallergens. Atopy was defined as ≥1 positive tests. Physician-diagnosed active asthma from age 6 to 32 and physician-diagnosed rhinitis at age 6 were determined by questionnaire. Participants with asthma or active wheezing at age 6 were excluded from analyses. Risk estimates were obtained with Cox regression. RESULTS: There were 521 participants who met inclusion criteria. The hazard ratio for subsequently acquiring a diagnosis of asthma between the ages of 8 and 32 for those with non-atopic rhinitis was 2.1 (95% CI: 1.2, 3.4, P = 0.005), compared with the non-atopic no rhinitis group, after adjusting for sex, ethnicity, maternal asthma, maternal education and smoking, and history of 4+ colds per year at age 6. Among the atopic participants, both the active and no rhinitis groups were more likely to develop and have asthma through age 32. The relation between non-atopic rhinitis and asthma was independent of total serum IgE levels at age 6. CONCLUSION AND CLINICAL RELEVANCE: Childhood rhinitis, even in the absence of atopy, confers significant risk for asthma development through adulthood. These findings underscore the importance of non-allergic mechanisms in the development of asthma.

Relation between circulating CC16 concentrations, lung function, and development of chronic obstructive pulmonary disease across the lifespan: a prospective study.

BACKGROUND: Low concentrations of the anti-inflammatory protein CC16 (approved symbol SCGB1A1) in serum have been associated with accelerated decline in forced expiratory volume in 1 s (FEV1) in patients with chronic obstructive pulmonary disease (COPD). We investigated whether low circulating CC16 concentrations precede lung function deficits and incidence of COPD in the general population. METHODS: We assessed longitudinal data on CC16 concentrations in serum and associations with decline in FEV1 and incidence of airflow limitation for adults who were free from COPD at baseline in the population-based Tucson Epidemiological Study of Airway Obstructive Disease ([TESAOD] n=960, mean follow-up 14 years), European Community Respiratory Health Survey ([ECRHS-Sp] n=514, 11 years), and Swiss Cohort Study on Air Pollution and Lung Diseases in Adults ([SAPALDIA] n=167, 8 years) studies. Additionally, we measured circulating CC16 concentrations in samples from children aged 4-6 years in the Tucson Children's Respiratory Study (n=427), UK Manchester Asthma and Allergy Study (n=481), and the Swedish Barn/children, Allergy, Milieu, Stockholm, Epidemiological survey (n=231) birth cohorts to assess whether low CC16 concentrations in childhood were predictive for subsequent lung function. FINDINGS: After adjustment for sex, age, height, smoking status and intensity, pack-years, asthma, and FEV1 at baseline, we found an inverse association between CC16 concentration and decline in FEV1 in adults in TESAOD (4·4 mL/year additional FEV1 decline for each SD decrease in baseline CC16 concentration, p=0·0014) and ECRHS-Sp (2·4 mL/year, p=0·023); the effect in SAPALDIA was marginal (4·5 mL/year, p=0·052). Low CC16 concentration at baseline was also associated with increased risk of incident stage 2 airflow limitation (ratio of FEV1 to forced expiratory volume [FEV1/FVC] less than 70% plus FEV1 % predicted less than 80%) in TESAOD and ECRHS-Sp. In children, the lowest tertile of CC16 concentrations was associated with a subsequent FEV1 deficit of 68 mL up to age 16 years (p=0·0001), which was confirmed in children who had never smoked by age 16 years (-71 mL, p<0·0001). INTERPRETATION: Low concentrations of CC16 in serum are associated with reduced lung function in childhood, accelerated lung function decline in adulthood, and development of moderate airflow limitation in the general adult population. FUNDING: National Heart, Lung, and Blood Institute and European Union Seventh Framework Programme.

Towards a PBMC "virogram assay" for precision medicine: Concordance between ex vivo and in vivo viral infection transcriptomes.

BACKGROUND: Understanding individual patient host-response to viruses is key to designing optimal personalized therapy. Unsurprisingly, in vivo human experimentation to understand individualized dynamic response of the transcriptome to viruses are rarely studied because of the obvious limitations stemming from ethical considerations of the clinical risk. OBJECTIVE: In this rhinovirus study, we first hypothesized that ex vivo human cells response to virus can serve as a proxy for otherwise controversial in vivo human experimentation. We further hypothesized that the N-of-1-pathways framework, previously validated in cancer, can be effective in understanding the more subtle individual transcriptomic response to viral infection. METHOD: N-of-1-pathways computes a significance score for a given list of gene sets at the patient level, using merely the 'omics profiles of two paired samples as input. We extracted the peripheral blood mononuclear cells (PBMC) of four human subjects, aliquoted in two paired samples, one subjected to ex vivo rhinovirus infection. Their dysregulated genes and pathways were then compared to those of 9 human subjects prior and after intranasal inoculation in vivo with rhinovirus. Additionally, we developed the Similarity Venn Diagram, a novel visualization method that goes beyond conventional overlap to show the similarity between two sets of qualitative measures. RESULTS: We evaluated the individual N-of-1-pathways results using two established cohort-based methods: GSEA and enrichment of differentially expressed genes. Similarity Venn Diagrams and individual patient ROC curves illustrate and quantify that the in vivo dysregulation is recapitulated ex vivo both at the gene and pathway level (p-values⩽0.004). CONCLUSION: We established the first evidence that an interpretable dynamic transcriptome metric, conducted as an ex vivo assays for a single subject, has the potential to predict individualized response to infectious disease without the clinical risks otherwise associated to in vivo challenges. These results serve as a foundational work for personalized "virograms".

Persistent insomnia is associated with mortality risk.

BACKGROUND: Insomnia has been associated with mortality risk, but whether this association is different in subjects with persistent vs intermittent insomnia is unclear. Additionally, the role of systemic inflammation in such an association is unknown. METHODS: We used data from a community-based cohort to determine whether persistent or intermittent insomnia, defined based on persistence of symptoms over a 6-year period, was associated with death during the following 20 years of follow-up. We also determined whether changes in serum C-reactive protein (CRP) levels measured over 2 decades between study initiation and insomnia determination were different for the persistent, intermittent, and never insomnia groups. The results were adjusted for confounders such as age, sex, body mass index, smoking, physical activity, alcohol, and sedatives. RESULTS: Of the 1409 adult participants, 249 (18%) had intermittent and 128 (9%) had persistent insomnia. During a 20-year follow-up period, 318 participants died (118 due to cardiopulmonary disease). In adjusted Cox proportional-hazards models, participants with persistent insomnia (adjusted hazards ratio [HR] 1.58; 95% confidence interval [CI], 1.02-2.45) but not intermittent insomnia (HR 1.22; 95% CI, 0.86-1.74) were more likely to die than participants without insomnia. Serum CRP levels were higher and increased at a steeper rate in subjects with persistent insomnia as compared with intermittent (P = .04) or never (P = .004) insomnia. Although CRP levels were themselves associated with increased mortality (adjusted HR 1.36; 95% CI, 1.01-1.82; P = .04), adjustment for CRP levels did not notably change the association between persistent insomnia and mortality. CONCLUSIONS: In a population-based cohort, persistent, and not intermittent, insomnia was associated with increased risk for all-cause and cardiopulmonary mortality and was associated with a steeper increase in inflammation.

The relation of circulating YKL-40 to levels and decline of lung function in adult life.

BACKGROUND: YKL-40 is a chitinase-like protein that, in cross-sectional clinical studies, has been associated with severe asthma and COPD in smokers. AIM: To determine the longitudinal relation of circulating YKL-40 to levels and decline of lung function in the general population. METHODS: We used longitudinal data from up to 13 surveys from the population-based TESAOD study which was conducted in Tucson, Arizona between 1972 and 1996. In cross-sectional analyses, we also used data from 3 Spanish centers of the multicenter ECRHS study (ECRHS-Sp). Serum YKL-40 was measured at baseline in TESAOD and in survey 2 in ECRHS-Sp using ELISAs. Multivariate linear regression was used to test associations of serum YKL-40 to concomitant lung function. In TESAOD, random coefficients models were used to test associations of serum YKL-40 to subsequent decline of lung function. RESULTS: Data on YKL-40 and lung function were available from 1088 TESAOD and 854 ECRHS-Sp adult participants (59% and 51% females; respectively). In adjusted multivariate meta-analyses, being in the highest YKL-40 quartile was associated cross-sectionally with significant deficits in FEV1 and FVC %predicted. In adjusted longitudinal analyses, TESAOD participants in the top YKL-40 quartile had an FEV1 decline that was 5 ml/yr (p = 0.05) faster than subjects in the third quartile, 5 ml/yr (p = 0.02) faster than subjects in the second quartile, and 10 ml/yr (p < 0.001) faster than subjects in the lowest YKL-40 quartile. These longitudinal effects were particularly strong in smokers and absent in never smokers. After adjusting for covariates, as compared with the other three quartiles combined, the top YKL-40 quartile was associated with a 9 ml/yr (p = 0.001) faster FEV1 decline among smokers, while no significant effects were found among never smokers (2 ml/yr, p = 0.35). CONCLUSIONS: Circulating YKL-40 is associated with levels and decline of lung function in the general population and may be a biomarker of susceptibility to the long-term effects of cigarette smoking.

Perinatal tumor necrosis factor-α production, influenced by maternal pregnancy weight gain, predicts childhood asthma.

RATIONALE: Innate immune responses marked by increases in tumor necrosis factor (TNF)-α have been associated with asthma but whether such alterations are evident before symptoms is not yet clear. OBJECTIVES: To determine if prevalence of childhood asthma or asthma-related traits is predicted by perinatal innate immune status and if maternal factors related to pregnancy influence asthma prevalence and innate immune status. METHODS: In the Tucson Infant Immune Study (a nonselected birth cohort), presence of eczema and wheezing in the child's first year and physician-diagnosed asthma through age 9 and asthma in the parents was obtained from parent-completed questionnaires. TNF-α, IL-6, IL-10, and IL-12 were measured in supernatants of LPS-stimulated peripheral blood mononuclear cells at birth and 3 months as was TNF-α in plasma. TNF-α single nucleotide polymorphisms were genotyped by Sequenom. Percent predicted FEV1/FVC was measured at age 9. Maternal weight gain during pregnancy and prepregnancy weight were ascertained from medical records. MEASUREMENTS AND MAIN RESULTS: Infants with persistently elevated LPS-induced TNF-α at birth and 3 months were at increased risk for childhood asthma (odds ratio [OR], 4.1; confidence interval [CI], 1.9-8.8; n = 233; P = 0.0003) and had decreased FEV1/FVC ratios at age 9. Children with mothers in the top tertile for pregnancy weight gain had increased risk for asthma (OR, 3.4; CI, 1.7-6.9; n = 225; P = 0.001) and persistently elevated TNF-α in early life (OR, 2.9; CI, 1.4-8.2; n = 195; P = 0.013). These relations were independent of maternal asthma and rhinitis. CONCLUSIONS: Persistently elevated LPS-induced TNF-α production early in life acts as a predictive biomarker for childhood asthma, and excess pregnancy weight gain in the mother seems to contribute to both.

Serum concentrations of club cell secretory protein (Clara) and cancer mortality in adults: a population-based, prospective cohort study.

BACKGROUND: Club cell secretory protein (Clara) (CC16) is produced mainly by bronchiolar club cells and has been shown to have protective effects against airway inflammation and oxidative stress from cigarette smoking and related carcinogens. The goal of this study was to establish whether serum CC16 concentrations predict all-cause and cancer-specific mortality in adults. METHODS: We used data from the population-based Tucson Epidemiological Study of Airway Obstructive Diseases (TESAOD), a prospective cohort study of respiratory health initiated in Tucson, AZ, USA, in 1972, that recruited a multistage stratified cluster sample of non-Hispanic white households. We measured serum CC16 concentrations in cryopreserved serum samples and reviewed vital status up to Jan 1, 2011, through contact with next of kin, collection of death certificates, and searches of the National Death Index. Our primary analysis was the relation of baseline serum CC16 to all-cause mortality or cause-specific mortality risk, analysed by adjusted Cox proportional hazards models. FINDINGS: 1086 TESAOD participants aged 21-70 years at enrolment were eligible for inclusion. Of these, 653 (60%) had died by 2011, and cause of death was ascertained for 649 (99%). When adjusted for sex, age, education, body-mass index, smoking and pack-years, and baseline levels of lung function, serum CC16 concentrations at baseline were inversely associated with mortality risk over the study follow-up. Mortality risk increased for each 1-SD decrease in CC16 (adjusted hazard ratio [HR] 1·16 [95% CI 1·06-1·26]; p=0·0007). For cause-specific mortality, each 1-SD decrease in serum CC16 was associated with an increased risk of dying of cancer (adjusted HR 1·41 [1·19-1·67]; p<0·0001). In the subset of smokers, the corresponding adjusted HR for mortality by lung cancer was 1·52 (1·14-2·03; p=0·004). INTERPRETATION: Serum CC16 concentrations can predict mortality risk in the general adult population. The excess risk associated with lower CC16 concentrations is predominantly driven by cancer, particularly lung cancer. FUNDING: National Heart, Lung, and Blood Institute.

Morbidity and mortality associated with the restrictive spirometric pattern: a longitudinal study.

BACKGROUND: Recent studies have suggested that a restrictive pattern assessed with a single spirometric test is associated with increased morbidity and mortality. This study was undertaken to determine demographic, clinical and mortality profiles of subjects with either a recurrent or an inconsistent restrictive spirometric pattern assessed prospectively. METHODS: Data from 2048 adult participants in the population-based TESAOD study were analysed. Normal (forced expiratory volume in 1 s/forced vital capacity (FEV(1)/FVC) ratio >or=70% and FVC >or=80% predicted), restrictive (FEV(1)/FVC >or=70% and FVC <80% predicted) and obstructive (FEV(1)/FVC <70%) patterns were assessed at the enrollment survey in 1972 and in 11 subsequent follow-up surveys up to 1996. Demographic and clinical characteristics were measured at enrollment and vital status and cause of death were assessed at January 2005. RESULTS: Overall, 12% of participants had a restrictive spirometric pattern at enrollment. They were less likely to be male, to smoke and to have asthma, and had lower IgE levels than subjects in the obstructive group. Among subjects with a restrictive pattern at enrollment, 38% developed an obstructive pattern during follow-up. The remaining 62% had either a recurrent (restrictive pattern >or=50% of follow-up surveys) or inconsistent (restrictive pattern <50% of follow-up surveys) longitudinal restrictive pattern. The recurrent and inconsistent restrictive groups had increased mortality risk for all-cause (adjusted HR 1.7 (95% CI 1.3 to 2.3) and 1.9 (95% CI 1.4 to 2.6), respectively), heart disease (2.0 (95% CI 1.3 to 3.1) and 2.7 (95% CI 1.7 to 4.3)), stroke (2.4 (95% CI 0.9 to 6.3) and 3.5 (95% CI 1.2 to 9.8)) and diabetes (8.0 (95% CI 2.9 to 21.8) and 6.0 (95% CI 1.9 to 19.2)). CONCLUSIONS: The restrictive spirometric pattern identifies a pulmonary condition that is distinguishable from obstructive lung disease and is associated with an increased risk of life-threatening comorbidities.

Wheezing and bronchial hyper-responsiveness in early childhood as predictors of newly diagnosed asthma in early adulthood: a longitudinal birth-cohort study.

BACKGROUND: Incidence of asthma increases during early adulthood. We aimed to estimate the contributions of sex and early life factors to asthma diagnosed in young adults. METHODS: 1246 healthy newborn babies were enrolled in the Tucson Children's Respiratory Study. Parental characteristics, early-life wheezing phenotypes, airway function, and bronchial hyper-responsiveness to cold dry air and sensitisation to Alternaria alternata were determined before age 6 years. Physician-diagnosed asthma, both chronic and newly diagnosed, and airway function were recorded at age 22 years. FINDINGS: Of 1246 babies enrolled, 849 had follow-up data at 22 years. Average incidence of asthma at age 16-22 years was 12.6 per thousand person-years. 49 (27%) of all 181 cases of active asthma at 22 years were newly diagnosed, of which 35 (71%) were women. Asthma remittance by 22 years was higher in men than in women (multinomial odds ratio [M-OR] 2.0, 95% CI 1.2-3.2, p=0.008). Age at diagnosis was linearly associated with the ratio of forced expiratory volume at 1 s to forced vital capacity at age 22 years. Factors independently associated with chronic asthma at 22 years included onset at 6 years (7.4, 3.9-14.0) and persistent wheezing (14.0, 6.8-28.0) in early life, sensitisation to A alternata (3.6, 2.1-6.4), low airway function at age 6 years (2.1, 1.1-3.9), and bronchial hyper-responsiveness at 6 years (4.5, 1.9-10.0). Bronchial hyper-responsiveness (6.9, 2.3-21.0), low airway function at 6 years (2.8, 1.1-6.9), and late-onset (4.6, 1.7-12.0) and persistent wheezing (4.0, 1.2-14.0) predicted newly diagnosed asthma at age 22 years. INTERPRETATION: Asthma with onset in early adulthood has its origins in early childhood.

The course of persistent airflow limitation in subjects with and without asthma.

RATIONALE: Most patients who develop persistent airflow limitation do so either as a manifestation of chronic obstructive pulmonary disease that is largely related to smoking or as a consequence of persistent asthma. We sought to compare the natural course of lung function associated with persistent airflow limitation in subjects with and without asthma from early to late adult life. METHODS: We studied 2552 participants aged 25 or more who had multiple questionnaire and lung function data from the long-term prospective population-based Tucson Epidemiological Study of Airway Obstructive Disease. Persistent airflow limitation was defined as FEV(1)/FVC ratio consistently < 70% in all completed surveys subsequent to the first survey with airflow limitation. Participants were divided into nine groups based on the combination of their physician-confirmed asthma status (never, onset < or = 25 years, or onset > 25 years) and the presence of airflow limitation during the study follow-up (never, inconsistent, or persistent). RESULTS: Among subjects with an asthma onset < or = 25 years, blood eosinophilia increased significantly the odds of developing persistent airflow limitation (adjusted ORs: 3.7, 1.4-9.5), whereas cigarette smoking was the strongest risk factor for persistent airflow limitation among non-asthmatics and among subjects with asthma onset after age 25 years. Among subjects with persistent airflow limitation, the natural course of lung function differed between subjects with asthma onset < or = 25 years and non-asthmatics, with the former having lower FEV(1) levels at age 25 (predicted value for a 175-cm tall male of 3400 versus 4090 ml, respectively; p<0.001) and the latter having greater FEV(1) loss between age 25 and 75 (1590 versus 2140 ml; p=0.003). CONCLUSION: In subjects who have asthma onset before 25 years of age and persistent airflow limitation in adult life, the bulk of the FEV(1) deficit is already established before age 25 years.

Effects of parental smoking on interferon gamma production in children.

OBJECTIVES: Environmental tobacco smoke is associated with several negative health outcomes in children, including an increased susceptibility to infections. One of the postulated mechanisms for these effects is the impairment of the immune system function and/or development. Yet, it remains unknown whether cumulative exposure to parental smoking is associated with altered immune responses in childhood and whether these effects are independent of in utero exposure to maternal smoking. In a population-based birth cohort, we sought to determine the relation of parental smoking, as assessed prospectively since pregnancy, to the child's interferon gamma and interleukin 4 production at 11 years of age. PATIENTS AND METHODS: We used data on 512 children and their parents from the Tucson Children's Respiratory Study cohort. Information on maternal and paternal smoking was collected prospectively by questionnaire, and pack-years for mother, father, and both parents combined were assessed prospectively between the prenatal period and year 11. At age 11 years, children's interferon gamma and interleukin 4 production from mitogen-stimulated peripheral blood mononuclear cells was measured. RESULTS: Children of parents who smoked between the prenatal period and year 11 were more likely to be in lower quartiles of interferon gamma production than children of nonsmoking parents. In addition, maternal, paternal, and parental pack-years showed significant inverse dose-response relationships with interferon gamma production in the child. These dose-response relationships with interferon gamma remained significant for both paternal and parental pack-years among children of mothers who did not smoke during pregnancy, suggesting the existence of specific postnatal effects of environmental tobacco smoke exposure. In contrast, no significant effects of parental smoking were found on interleukin 4 production. CONCLUSIONS: Interferon gamma responses of school-aged children are impacted by parental smoking.

Suppression of innate immune cytokines and interferon regulatory factor-1 by endogenous interferon-alpha in response to respiratory syncytial virus in neonate mononuclear cells.

Respiratory syncytial virus (RSV) infections are extremely common in early childhood but are most severe in infants in the first few months of life. Unresponsive adaptive immunity and hyporesponsive innate immunity were previously found to be the typical responses of neonate mononuclear cells (MCs) to live RSV. Investigating the mechanism of innate immune hyporesponsiveness in neonate MCs to live RSV revealed that in contrast to the previously reported low expression of interferon (IFN)-gamma, IFN-alpha expression in response to live RSV was significantly greater than that observed in adult MCs. Inhibition of live RSV-induced IFN-alpha with anti-IFN-alpha antibodies in neonate MCs led to significant increases in innate cytokine [IFN-gamma, interleukin (IL)-12, IL-18 and tumor necrosis factor (TNF)-alpha] but not adaptive immune cytokine [IL-2] production. Although MCs from adults responded to live RSV with upregulation of interferon regulatory factor-1 (IRF-1) mRNA, IRF-1 mRNA in RSV-treated neonate MCs was not detectable. However, in the presence of anti-IFN-alpha antibodies, live RSV induced detectable IRF-1 mRNA expression in neonate MCs. These data support the possibility that the severity of early life RSV-induced illnesses may occur via a mechanism in which live RSV induces IFN-alpha that in turn leads to innate immune suppression in neonate MCs.

Differences in participation of innate and adaptive immunity to respiratory syncytial virus in adults and neonates.

Innate and adaptive immune responses to respiratory syncytial virus (RSV) in neonates were assessed by cord blood mononuclear cell (MC) cytokine expression and proliferation and these responses were compared with those from adult peripheral blood MCs. In adult cells, inactivated and live virus invoked cytokines reflecting both innate and adaptive immunity (interleukin [IL]-6, interferon [IFN]-gamma, IL-2, tumor necrosis factor [TNF]-alpha, and IL-10). Low levels of IL-4 were detected, although only with inactivated virus. In contrast, in neonatal cells, inactivated virus invoked large levels of the innate immune cytokines IL-6, TNF-alpha, and IL-10 and reduced levels of IFN-gamma and IL-12 but no adaptive cytokines. Live virus induced fewer innate (IL-6, IL-10, and IFN-gamma) and no adaptive immune cytokines. RSV-induced proliferation was absent in neonatal MCs, although positive in adult MCs. Thus, exposure to RSV does not appear to occur before birth, and adaptive immune insufficiency or greater innate responses may account for early life RSV-induced illnesses.