Home-Based Double-Blind, Placebo-Controlled Challenges for Diagnosis of Delayed Gluten/Milk Hypersensitivity in Children.

BACKGROUND: Delayed hypersensitivity to gluten and milk protein is frequently reported but may be difficult to diagnose. OBJECTIVE: We aimed to explore if a method of home-based double-blind placebo-controlled food challenges (H-FC) can identify and reduce unnecessary elimination diets in children. METHODS: We included 73 of 92 children aged 1 to 17 years referred to a tertiary allergy clinic from 2011 to 2021 due to self-reported, delayed symptoms to gluten or milk. The children were randomized to H-FC, receiving gluten/milk protein or placebo for 5 to 7 days in a double-blind crossover manner, separated by 3 washout weeks. Patients/parents recorded symptoms using standardized forms. Two crossover periods were used from 2011 to 2016 and 3 periods from 2017 to 2021. A positive challenge required significantly more symptoms during the active period versus the placebo period. After the challenge, reintroduction of milk/gluten was assessed by a follow-up interview. The primary outcome was the proportion of children with a positive challenge. RESULTS: The children, with a mean age of 11 years, had followed a strict gluten-free or milk-protein-free diet for a median duration of 24 months (range: 3-180 months). A positive challenge was observed in 18 of 73 children (25%), more often using 2 (35%) compared with 3 challenge periods (12%). At follow-up, 44 of 55 (80%) children with a negative challenge had successfully reintroduced milk/gluten. CONCLUSIONS: H-FC may be an effective method in avoiding unnecessary elimination diets in children. Only 25% of the challenges were positive, and 80% of the children with negative challenges succeeded in reintroducing the food. Three challenge periods may be necessary to reduce false-positive outcomes.

Early food intervention and skin emollients to prevent food allergy in young children (PreventADALL): a factorial, multicentre, cluster-randomised trial.

BACKGROUND: Primary prevention of food allergy by early introduction of allergenic foods seems promising. We aimed to determine whether early food introduction or the application of regular skin emollients in infants from a general population reduced the risk of food allergy. METHODS: This 2 × 2 factorial, cluster-randomised trial was done at Oslo University Hospital and Østfold Hospital Trust, Oslo, Norway, and Karolinska University Hospital, Stockholm, Sweden. Infants of women recruited antenatally at the routine 18-week ultrasound examination were cluster-randomised at birth to the following groups: (1) no intervention group; (2) the skin intervention group (skin emollients; bath additives and facial cream; from age 2 weeks to <9 months, both at least four times per week); (3) the food intervention group (early complementary feeding of peanut, cow's milk, wheat, and egg from age 3 months); or (4) combined intervention group (skin and food interventions). Participants were randomly assigned (1:1:1:1) using computer-generated randomisation based on clusters of 92 geographical areas and eight 3-month time blocks. Study personnel performing clinical assessments were masked to group allocation. The primary outcome was allergy to any interventional food at 36 months of age. The primary efficacy analysis was done by intention-to-treat analysis, which included all participants who were randomly assigned, apart from three individuals who withdrew their consent. This was a study performed within ORAACLE (the Oslo Research Group of Asthma and Allergy in Childhood; the Lung and Environment). This study is registered as ClinicalTrials.gov, NCT02449850. FINDINGS: We recruited 2697 women with 2701 pregnancies, from whom 2397 newborn infants were enrolled between April 14, 2015, and April 11, 2017. Of these infants, 597 were randomly assigned to the no intervention group, 575 to the skin intervention group, 642 to the food intervention group, and 583 to the combined intervention group. One participant in each of the no intervention, food intervention, and skin intervention groups withdrew consent and were therefore not included in any analyses. Food allergy was diagnosed in 44 children; 14 (2·3%) of 596 infants in the non-intervention group, 17 (3·0%) of 574 infants in the skin intervention group, six (0·9%) of 641 infants in the food intervention group, and seven (1·2%) of 583 infants in the combined intervention group. Peanut allergy was diagnosed in 32 children, egg allergy in 12 children, and milk allergy in four children. None had allergy to wheat. Prevalence of food allergy was reduced in the food intervention group compared with the no food intervention group (risk difference -1·6% [95% CI -2·7 to -0·5]; odds ratio [OR] 0·4 [95% CI 0·2 to 0·8]), but not compared with the skin intervention group (0·4% [95% CI -0·6 to 1· 5%]; OR 1·3 [0·7 to 2·3]), with no significant interaction effect (p=1·0). Preventing food allergy in one child required early exposure to allergenic foods in 63 children. No serious adverse events were observed. INTERPRETATION: Exposure to allergenic foods from 3 months of age reduced food allergy at 36 months in a general population. Our results support that early introduction of common allergenic foods is a safe and effective strategy to prevent food allergy. FUNDING: Full funding sources listed at end of paper (see Acknowledgments).

Helicobacter pylori in early childhood and asthma in adolescence.

OBJECTIVE: An inverse effect of Helicobacter pylori (H. pylori) on the occurrence of asthma is debated and early acquisition of H. pylori may be important. We analyzed sera from 197 children from Environment and Childhood Asthma (ECA) study in Oslo for Helicobacter pylori (H. pylori) at 2 and 10 years, and symptoms and signs of asthma at 16 years of age. RESULTS: While 16.4% of children who were H. pylori negative at 2 and 10 years had current asthma at 16 years, none of the 12 children who were H. pylori positive at 2 years of age had asthma at the age of 16 years, regardless of H. pylori status at 10 years. This trend for less current asthma in children who were H. pylori positive at 2 years compared to persistent or transient negative status at 10 years was not statistically significant, probably due to low number of H. pylori positive children at 2 years of age. Acquisition of H. pylori in school age did not appear to influence the risk of current asthma. Much larger prospective studies are probably required to document whether or not early H. pylori infection may be involved in the risk of asthma development in later childhood.

Skin emollient and early complementary feeding to prevent infant atopic dermatitis (PreventADALL): a factorial, multicentre, cluster-randomised trial.

BACKGROUND: Skin emollients applied during early infancy could prevent atopic dermatitis, and early complementary food introduction might reduce food allergy in high-risk infants. The study aimed to determine if either regular skin emollients applied from 2 weeks of age, or early complementary feeding introduced between 12 and 16 weeks of age, reduced development of atopic dermatitis by age 12 months in the general infant population. METHODS: This population-based 2×2 factorial, randomised clinical trial was done at Oslo University Hospital and Østfold Hospital Trust, Oslo, Norway; and Karolinska University Hospital, Stockholm, Sweden. Infants of women recruited antenatally at the routine ultrasound pregnancy screening at 18 weeks were cluster-randomised at birth from 2015 to 2017 to the following groups: (1) controls with no specific advice on skin care while advised to follow national guidelines on infant nutrition (no intervention group); (2) skin emollients (bath additives and facial cream; skin intervention group); (3) early complementary feeding of peanut, cow's milk, wheat, and egg (food intervention group); or (4) combined skin and food interventions (combined intervention group). Participants were randomly assigned (1:1:1:1) using computer- generated cluster randomisation based on 92 geographical living area blocks as well as eight 3-month time blocks. Carers were instructed to apply the interventions on at least 4 days per week. Atopic dermatitis by age 12 months was the primary outcome, based on clinical investigations at 3, 6 and 12 months by investigators masked to group allocation. Atopic dermatitis was assessed after completing the 12-month investigations and diagnosed if either of the UK Working Party and Hanifin and Rajka (12 months only) diagnostic criteria were fulfilled. The primary efficacy analyses was done by intention-to-treat analysis on all randomly assigned participants. Food allergy results will be reported once all investigations at age 3 years are completed in 2020. This was a study performed within ORAACLE (the Oslo Research Group of Asthma and Allergy in Childhood; the Lung and Environment). The study is registered at clinicaltrials.gov, NCT02449850. FINDINGS: 2697 women were recruited between Dec 9, 2014, and Oct 31, 2016, from whom 2397 newborn infants were enrolled from April 14, 2015, to April 11, 2017. Atopic dermatitis was observed in 48 (8%) of 596 infants in the no intervention group, 64 (11%) of 575 in the skin intervention group, 58 (9%) of 642 in the food intervention group, and 31 (5%) of 583 in the combined intervention group. Neither skin emollients nor early complementary feeding reduced development of atopic dermatitis, with a risk difference of 3·1% (95% CI -0·3 to 6·5) for skin intervention and 1·0% (-2·1 to 4·1) for food intervention, in favour of control. No safety concerns with the interventions were identified. Reported skin symptoms and signs (including itching, oedema, exanthema, dry skin, and urticaria) were no more frequent in the skin, food, and combined intervention groups than in the no intervention group. INTERPRETATION: Neither early skin emollients nor early complementary feeding reduced development of atopic dermatitis by age 12 months. Our study does not support the use of these interventions to prevent atopic dermatitis by 12 months of age in infants. FUNDING: The study was funded by several public and private funding bodies: The Regional Health Board South East, The Norwegian Research Council, Health and Rehabilitation Norway, The Foundation for Healthcare and Allergy Research in Sweden-Vårdalstiftelsen, Swedish Asthma and Allergy Association's Research Foundation, Swedish Research Council-the Initiative for Clinical Therapy Research, The Swedish Heart-Lung Foundation, SFO-V at the Karolinska Institute, Freemason Child House Foundation in Stockholm, Swedish Research Council for Health, Working Life and Welfare-FORTE, Oslo University Hospital, the University of Oslo, and Østfold Hospital Trust.

Parent and child perception of quality of life in a randomized controlled peanut oral immunotherapy trial.

BACKGROUND: Improved quality of life (QoL) after oral immunotherapy (OIT) in peanut allergic children is often reported by their parents, while the child's perspective is less clear. OBJECTIVE: We aimed to explore whether 2 years of OIT improved QoL in children with peanut allergy and to identify factors influencing change in QoL. METHODS: In the open-labeled TAKE-AWAY peanut OIT trial including children with anaphylaxis to peanuts, 57 were randomized to OIT and 20 to observation. The Pediatric Quality of Life Inventory Version 4.0 was completed by parents and children at enrollment (Y0 ), after 1 year (end of updosing; Y1 ) and after 2 years (Y2 ) of OIT. Minimally clinically important difference (MCID) is ≥5.3. Perceived treatment burden was recorded by visual analogue scales, including adverse events (AEs). An open food challenge (OFC) was performed at Y2 . RESULTS: At Y2 , 18 children had discontinued OIT and 2 of 39 OIT children refused OFC, while 35 of 37 were desensitized to 7500 mg peanut protein. From Y0 to Y2, the mean change (95% confidence intervals) in QoL was 4.4 (0.5, 8.3) among child self-reports and twice as large among parental proxy reports (9.3 [4.3, 14.3]; both P < 0.0001), without significant improvement among the controls. The change in QoL was significantly different from the controls for the parental proxy reports only (P = 0.002). Neither treatment burden nor AEs significantly predicted changes in QoL. CONCLUSION: Two years of OIT improved child-QoL as reported by parents, but not by the children, suggesting that parents may overestimate improvement in child-QoL by OIT.

Feasibility of desensitizing children highly allergic to peanut by high-dose oral immunotherapy.

BACKGROUND: There are limited data on the feasibility, efficacy and safety of high-dose oral immunotherapy (OIT) in children highly allergic to peanuts. OBJECTIVE: In children highly allergic to peanut, we primarily aimed to determine the feasibility of reaching the maximum maintenance dose (MMD) of 5000 mg peanut protein or, alternatively, a lower individual maintenance dose (IMD), by OIT up-dosing. Secondarily, we aimed to identify adverse events (AEs) and determine factors associated with reaching a maintenance dose. METHODS: The TAKE-AWAY peanut OIT trial enrolled 77 children 5-15 years old, with a positive oral peanut challenge. Fifty-seven were randomized to OIT with biweekly dose step-up until reaching MMD or IMD and 20 to observation only. Demographic and biological characteristics, AEs, medication and protocol deviations were explored for associations with reaching maintenance dose. RESULTS: All children had anaphylaxis defined by objective symptoms in minimum two organ systems during baseline challenge. The MMD was reached by 21.1%, while 54.4% reached an IMD of median (minimum, maximum) 2700 (250, 4000) mg peanut protein, whereas 24.5% discontinued OIT. During up-dosing, 19.4% experienced anaphylaxis. Not reaching the MMD was caused by distaste for peanuts (66.7%), unacceptable AEs (26.7%) and social reasons (6.7%). Increased peanut s-IgG4 /s-IgE ratio (OR [95% CI]: 1.02 [1.00, 1.04]) was associated with reaching MMD. CONCLUSION: Although 75.5% of children with peanut anaphylaxis reached a maintenance dose of 0.25-5 g, only 21.1% reached the MMD. Distaste for peanuts and AEs, including high risk of anaphylaxis, limited the feasibility of reaching MMD.

Perceived exercise limitation in asthma: The role of disease severity, overweight, and physical activity in children.

BACKGROUND: Children with asthma may be less physically active than their healthy peers. We aimed to investigate whether perceived exercise limitation (EL) was associated with lung function or bronchial hyper-responsiveness (BHR), socioeconomic factors, prenatal smoking, overweight, allergic disease, asthma severity, or physical activity (PA). METHODS: The 302 children with asthma from the 10-year examination of the Environment and Childhood Asthma birth cohort study underwent a clinical examination including perceived EL (structured interview of child and parent(s)), measure of overweight (body mass index by sex and age passing through 25 kg/m2 or above at 18 years), exercise-induced bronchoconstriction (forced expiratory volume in one-second (FEV1 ) pre- and post-exercise), methacholine bronchial challenge (severe BHR; provocative dose causing ≥20% decrease in FEV1 ≤ 1 µmol), and asthma severity score (dose of controller medication and exacerbations last 12 months). Multivariate logistic regression analyses were conducted to assess associations with perceived EL. RESULTS: In the final model explaining 30.1%, asthma severity score (OR: 1.49, (1.32, 1.67)) and overweight (OR: 2.35 (1.14, 4.82)) only were significantly associated with perceived EL. Excluding asthma severity and allergic disease, severe BHR (OR: 2.82 (1.38, 5.76)) or maximal reduction in FEV1 post-exercise (OR: 1.48 (1.10, 1.98)) and overweight (OR: 2.15 (1.13, 4.08) and 2.53 (1.27, 5.03)) explained 9.7% and 8.4% of perceived EL, respectively. CONCLUSIONS: Perceived EL in children with asthma was independently associated with asthma severity and overweight, the latter doubling the probability of perceived EL irrespectively of asthma severity, allergy status, socioeconomic factors, prenatal smoking, or PA.

Lung function trajectories from birth through puberty reflect asthma phenotypes with allergic comorbidity.

BACKGROUND: Childhood asthma phenotypes reflecting underlying developmental mechanisms are sought, with little information on asthma phenotypes based on allergic comorbidities. OBJECTIVE: We asked whether lung function trajectories from birth to 16 years were associated with asthma phenotypes with comorbid allergic rhinitis and atopic dermatitis. METHODS: Lung function (given as z scores) was measured at birth in 329 subjects in the "Environment and Childhood Asthma" birth cohort study in Oslo by using tidal flow volume loops, and at 10 and 16 years by using spirometry. Asthma phenotypes were classified on the basis of recurrent bronchial obstruction at 0 to 2 years, and asthma from the 2- to 10-year and 10- to 16-year intervals, and by combining asthma, atopic dermatitis, and/or allergic rhinitis from 10 to 16 years, stratifying for allergic sensitization. The reference group included 231 subjects without recurrent bronchial obstruction or asthma. RESULTS: Lung function trajectories differed significantly for asthma comorbidity phenotypes for FEV1, forced expiratory flow at 25% to 75% of forced vital capacity, and FEV1/forced vital capacity (all P < .0001). Significant lung function impairment was observed from birth through 16 years among subjects with asthma, atopic dermatitis, and allergic rhinitis. Lung function trajectories in subjects with asthma at 10 to 16 years or asthma in remission differed significantly for all 3 spirometric values compared with the trajectories in those who never had asthma (P < .0001), but not between asthma groups. Allergic sensitization was not significantly associated with asthma phenotype lung function trajectories. CONCLUSIONS: The trajectory consisting of impaired lung function from birth throughout childhood in children with asthma, atopic dermatitis, and allergic rhinitis appears less likely to be driven by allergic sensitization, and may imply disease onset in utero, with clinical presentation later in childhood.

Urinary biomarkers for phthalates associated with asthma in Norwegian children.

BACKGROUND: High-molecular-weight phthalates in indoor dust have been associated with asthma in children, but few studies have evaluated phthalate biomarkers in association with respiratory outcomes. OBJECTIVES: We explored the association between urinary concentrations of phthalate metabolites and current asthma. METHODS: In a cross-sectional analysis, 11 metabolites of 8 phthalates [including four metabolites of di(2-ethylhexyl) phthalate] were measured in one first morning void collected from 2001 through 2004 from 623 10-year-old Norwegian children. Logistic regression models controlling for urine specific gravity, sex, parental asthma, and income were used to estimate associations between current asthma and phthalate metabolite concentrations by quartiles or as log10-transformed variables. RESULTS: Current asthma was associated with both mono(carboxyoctyl) phthalate (MCOP) and mono(carboxynonyl) phthalate (MCNP), although the association was limited to those in the highest quartile of these chemicals. The adjusted odds ratio (aOR) for current asthma was 1.9 (95% CI: 1.0, 3.3) for the highest MCOP quartile compared with the lowest quartile, and 1.3 (95% CI: 0.98, 1.7) for an interquartile-range increase. The aOR for current asthma was 2.2 (95% CI: 1.2, 4.0) for the highest MCNP quartile and 1.3 (95% CI: 1.0, 1.7) for an interquartile-range increase. The other phthalate metabolites were not associated with current asthma. CONCLUSIONS: Current asthma was associated with the highest quartiles of MCOP and MCNP, metabolites of two high molecular weight phthalates, diisononyl phthalate and diisodecyl phthalate, respectively. Given the short biological half-life of the phthalates and the cross-sectional design, our findings should be interpreted cautiously.

Paracetamol in early infancy: the risk of childhood allergy and asthma.

AIM: We investigated whether paracetamol exposure in pregnancy and until 6 months of age was associated with allergic disease in school children. METHODS: In a prospective birth cohort study in Oslo, 1016 children included at birth were re-investigated at 10 years. Paracetamol exposure in pregnancy and until 6 months of age was registered. Outcomes at 10 years included current asthma, a history of asthma, allergic sensitization and allergic rhinitis. RESULTS: Maternal paracetamol use in the first trimester increased the risk for allergic rhinitis at 10 years OR (odds ratio) (95%CI) 2.30 (1.06, 4.97) in boys and girls. Paracetamol use until 6 months in girls increased the risk for allergic sensitization OR 2.20 (1.15, 4.22) and a history of asthma OR 2.20 (1.13, 4.30). The ORs for allergic sensitization and history of asthma in girls remained unchanged adjusting for upper or lower airway infections during the first 6 months of life. CONCLUSION: Paracetamol exposure in pregnancy was associated with allergic rhinitis, but not with asthma or allergic sensitization at 10 years of age. Paracetamol used until 6 months of age was associated with allergic sensitization and having a history of asthma in girls at 10 years of age, even considering concomitant airway infections.

Lung function at 10 yrs is not improved by early corticosteroid treatment in asthmatic children.

Early intervention with inhaled corticosteroid (ICS) treatment for lung function development in childhood is debated. In view of lung function at birth, we aimed to assess if early use of ICS influenced lung function at 10 yrs of age. A 10-yr follow-up study of 614/802 children (mean age 10.9 +/- 0.9 yrs) with lung function measurements at birth in the Environment and Childhood Asthma study in Oslo included information on ICS treatment (124 with history of asthma) obtained at 2 and 10 yrs by parental interviews. Main outcomes at 10 yrs were the best values (% predicted and Z-scores) of forced expiratory volume in 1 s (FEV(1)) and mid-expiratory flow. The main explanatory factors were never, past or current use of ICS and Z-scores of the tidal flow-volume ratio t(PTEF)/t(E) [time to peak expiratory flow (t(PTEF)) and total expiratory time (t(E))] at birth. ICS treatment, reported by 11.9% of children in the population sample and 71.6% with current asthma, did not significantly influence lung function from birth to 10 yrs. The best values (and Z-scores) of FEV(1), and mid-expiratory flow were similar (p > 0.1) in subjects receiving ICS during and after 0-3 yrs of age, after 3 yrs only or currently compared with steroid naïve children. Almost half of the change in lung function 0-10 yrs was explained by gender, a history of asthma and t(PTEF)/t(E) at birth. ICS treatment for asthma, reported in every eighth child by age 10 yrs, did not significantly improve lung function from birth to 10 yrs.

Lung function at 10 yr is not impaired by early childhood lower respiratory tract infections.

The causal relationship between lower respiratory tract infections (LRIs) in early life and reduced lung function later in childhood is unsettled. Therefore, we assessed whether LRIs the first 2 yr of life influenced lung function development from birth to school age. In the prospective Oslo birth cohort, 'the Environment and Childhood Asthma (ECA) study' lung function was measured at birth in 802 infants by tidal flow volume loops and in 664 infants by passive respiratory mechanics and half yearly questionnaires, including LRI questions, were completed until 2 yr of age. The present study includes 607 children with information about LRIs the first 2 yr of life and successfully forced expiratory flow (FEF) volume measurements at the 10-yr follow-up assessment. At 10 yr of age, FEF at 50% of forced vital capacity (FEF(50)) (mean 95% confidence interval) was reduced in children with at least one bronchiolitis (85.0, 80.6-89.5, p = 0.020) or bronchitis (86.2, 82.6-89.8, p = 0.030) or > or =3 LRIs (83.4, 78.1-88.8, p = 0.017) when compared with no LRIs (90.6, 88.8-92.5) by 2 yr of life. The effects were significant in girls only when stratifying for gender. Among girls with later bronchiolitis compliance of the respiratory system (3.64, 3.17-4.10 vs. 4.18, 3.98-4.37, p = 0.031) and the ratio of time to peak tidal expiratory flow to total expiratory time (t(PTEF)/t(E)) measured at birth was significantly reduced (0. 26, 0.23-0.29 vs. 0.32, 0.30-0.33, p = 0.005) when compared with children with no LRIs. Change in lung function from birth (by t(PTEF)/t(E)) to 10 yr of age was not significantly associated with LRIs the first 2 yr of life, and LRIs by 2 yr of life were not significantly associated with lung function at 10 yr of age in regression analyses including lung function at birth and other possible predictors of lung function at 10 yr. In our study, LRIs during the first 2 yr of life did not impair lung function development from birth until 10 yr of age.

Natural history of lung function in health and diseases.

PURPOSE OF REVIEW: To outline major advances in the understanding of factors that influence lung function development through childhood. RECENT FINDINGS: New study approaches such as adjusting for 'tracking' or analysing without predefined phenotypes suggest that reduced lung function reported with several pre or coexisting features such as lower respiratory tract infections and early allergic sensitization may be spurious rather than causative. Also, two large, recent studies have clearly demonstrated that living close to major roads causes significant lung function deficits in school children, with the possible long-term impact this can have on health in adult life. Furthermore, it is becoming clear that we need to focus upon early life events that can cause harm as well as have a potential for catch-up growth or development in postnatal life. SUMMARY: The implications of these findings are clearly that there is a potential for intervening in a potential pathological development. Furthermore, there is a clear need to focus research upon early life events that can improve lung growth in the damaged lung and prevent damage to the potentially healthy lung at the very start of life.

T cell-specific T-box transcription factor haplotype is associated with allergic asthma in children.

BACKGROUND: T cell-specific T-box transcription factor (T-bet) is a member of the T-box family of transcription factors regulating lineage commitment of T(H) lymphocytes toward a predominant T(H)1 phenotype. Asthma and allergy are common complex diseases characterized by T(H)2-mediated inflammation. OBJECTIVE: We aimed to assess possible relationships between the T-bet gene (TBX21) and asthma and allergy in children. METHOD: Twelve single nucleotide polymorphisms (SNPs) in the TBX21 region were genotyped in 948 children from the Environment and Childhood Asthma study. Allele and haplotype frequencies were compared in children with and without asthma (by 10 years) and allergy (> or =1 positive skin prick test response), as well as for the quantitative traits bronchial hyperresponsiveness determined by means of methacholine bronchial challenge testing, lung function determined by means of forced flow volume loops, fractional exhaled nitric oxide measurement, eosinophil count, and serum total IgE level. RESULTS: Allergic asthma was significantly associated with 2 of the tested SNPs (rs11650354 and rs16947078) and further associated with the particular haplotype including these SNPs, with homozygote status resulting in an odds ratio of 8.3 (95% CI, 2.5-26.9) for allergic asthma. Neither nonallergic asthma or "allergy alone" nor the remaining quantitative variables were associated with TBX21 SNPs or haplotypes. CONCLUSION: An association between a specific TBX21 haplotype and allergic asthma in children is demonstrated for the first time and might explain previously detected associations between SNPs within TBX21 and asthma and bronchial hyperresponsiveness.

Lung function development in the first 2 yr of life is independent of allergic diseases by 2 yr.

The aim of the study was to assess if lung function at birth predicts lung function at 2 yr and secondly, if lung function development was influenced by the common phenotypes of recurrent bronchial obstruction (rBO) or atopic eczema (AE) by 2 yr. Lung function was assessed at birth (n = 802) and at 2 yr within the prospective birth cohort study 'the Environment and Childhood Asthma Study' in Oslo. The 135 children with lung function measured at birth by tidal flow volume (TFV) loops and passive respiratory mechanics, who were included in a nested case-control study were reinvestigated at 2 yr with clinical examination, TFV loops (n = 90) (mean age 26.6 (3.7 s.d.) months), skin prick test and parental interview. Children were categorized into quartiles (lower, middle two, upper) according to time to peak tidal expiratory flow/total expiratory time (t(PTEF)/t(E)) at birth as well as clinical phenotype based on the presence of rBO and/or AE (ever) by 2 yr. The observed reduction in mean t(PTEF)/t(E) from birth to 2 yr within the quartiles, were not significantly different after controlling for 'regression to the mean'. t(PTEF)/t(E) at birth correlated significantly with t(PTEF)/t(E) at 2 yr, (r = 0.475, p < 0.001). Children with both rBO and AE by 2 yr had significantly lower t(PTEF)/t(E) at 2 yr (p = 0.002) and at birth (p = 0.027), compared with children with no rBO or AE. Clinical phenotype at 2 yr did not influence the change in t(PTEF)/t(E) from birth to 2 yr. This study demonstrates a clear tracking of lung function from birth, not influenced by rBO or AE by 2 yr.

No evidence that early use of inhaled corticosteroids reduces current asthma at 10 years of age.

BACKGROUND: It is debated whether early treatment with inhaled corticosteroids (ICS) can change the natural course of childhood asthma. AIM: To assess if ICS treatment before 2 years of age in children with obstructive airways disease reduces current asthma at 10 years of age. METHODS: Children with (n=233) and without (n=219) recurrent (r) bronchial obstruction (BO) attending clinical examination at 2 years of age in the birth cohort Environment and Childhood Asthma study in Oslo, were reinvestigated at 10 years of age. Current asthma (CA) at 10 years was defined as asthma with either symptoms and/or asthma treatment during the last year, and/or 10% fall in forced expired volume in 1s after standardized treadmill run. The risk of CA was assessed by logistic regression and propensity modelling (including gender, parental atopy and severity score at 2 years) in children with rBO who received ICS or not by 2 years. RESULTS: CA was found in 97 children, more often among rBO children with (56.9%) and without ICS treatment (30.8%) compared to no-BO children (5.5%) (p<0.001). In rBO children logistic regression analyses (adjusted odds ratio aOR (95% confidence interval)) identified male gender (aOR 1.82 (1.01-3.27), p=0.046) and severity score at 2 years 1.14 (1.03-1.28), (p=0.01), as significant and ICS treatment as non-significant 2.00 (0.98-4.12) risk factors for CA. With propensity modelling adjusting for disease severity, ICS treatment by 2 years caused a non-significant increased risk aOR of CA of 1.84 (0.89-3.82). CONCLUSION: No evidence was found that early use of ICS before age two in children with rBO reduces current asthma 8 years later.

Reduced lung function at birth and the risk of asthma at 10 years of age.

BACKGROUND: Reduced lung function in early infancy has been associated with later obstructive airway diseases. We assessed whether reduced lung function shortly after birth predicts asthma 10 years later. METHODS: We conducted a prospective birth cohort study of healthy infants in which we measured lung function shortly after birth with the use of tidal breathing flow-volume loops (the fraction of expiratory time to peak tidal expiratory flow to total expiratory time [t(PTEF)/t(E)]) in 802 infants and passive respiratory mechanics, including respiratory-system compliance, in 664 infants. At 10 years of age, 616 children (77%) were reassessed by measuring lung function, exercise-induced bronchoconstriction, and bronchial hyperresponsiveness (by means of a methacholine challenge) and by conducting a structured interview to determine whether there was a history of asthma or current asthma. RESULTS: As compared with children whose t(PTEF)/t(E) shortly after birth was above the median, children whose t(PTEF)/t(E) was at or below the median were more likely at 10 years of age to have a history of asthma (24.3% vs. 16.2%, P=0.01), to have current asthma (14.6% vs. 7.5%, P=0.005), and to have severe bronchial hyperresponsiveness, defined as a methacholine dose of less than 1.0 micromol causing a 20% fall in the forced expiratory volume in 1 second (FEV1) (9.1% vs. 4.9%, P=0.05). As compared with children whose respiratory-system compliance was above the median, children with respiratory compliance at or below the median more often had a history of asthma (27.4% vs. 14.8%; P=0.001) and current asthma (15.0% vs. 7.7%, P=0.009), although this measure was not associated with later measurements of lung function. At 10 years of age, t(PTEF)/t(E) at birth correlated weakly with the maximal midexpiratory flow rate (r=0.10, P=0.01) but not with FEV1 or forced vital capacity. CONCLUSIONS: Reduced lung function at birth is associated with an increased risk of asthma by 10 years of age.