Cough during infancy and subsequent childhood asthma.

OBJECTIVES: Wheezing in infancy has been associated with subsequent asthma, but whether cough similarly influences asthma risk has been little studied. We sought to determine whether prolonged cough and cough without cold in the first year of life are associated with childhood asthma. METHODS: Participants in the Infant Immune Study, a non-selected birth cohort, were surveyed 7 times in the first 9 months of life regarding the presence of wheeze and cough. Cough for more than 28 days was defined as prolonged. Parents were asked at 1 year if the child ever coughed without a cold. Asthma was defined as parental report of physician diagnosis of asthma, with symptoms or medication use between 2 and 9 years. Logistic regression was used to assess adjusted odds for asthma associated with cough characteristics. RESULTS: A total of 24% (97) of children experienced prolonged cough and 23% (95) cough without cold in the first 9 months, respectively. Prolonged cough was associated with increased risk of asthma relative to brief cough (OR 3.57, CI: 1.88, 6.76), with the risk being particularly high among children of asthmatic mothers. Cough without cold (OR 3.13, 95% CI: 1.76, 5.57) was also independently associated with risk of childhood asthma. Both relations persisted after adjustment for wheeze and total IgE at age 1. CONCLUSIONS AND CLINICAL RELEVANCE: Prolonged cough in infancy and cough without cold are associated with childhood asthma, independent of infant wheeze. These findings suggest that characteristics of cough in infancy are early markers of asthma susceptibility, particularly among children with maternal asthma.

Relation of early antibiotic use to childhood asthma: confounding by indication?

BACKGROUND: Findings from studies of the relation between early antibiotic use and subsequent asthma have been inconsistent, which may be attributable to methodologic issues. OBJECTIVE: Our objective was to assess the impact of confounding by indication on the relation of early antibiotic use to childhood asthma through age 5 in a non-selected birth cohort (n=424). METHODS: Oral antibiotic use was assessed by frequent nurse interviews in the first 9 months of life. Physician-diagnosed active asthma and eczema were assessed by questionnaire at 1, 2, 3, and 5 years, and were considered as ever asthma or ever eczema if positive at any age. Allergen-specific IgE was assessed in plasma at 1, 2, 3, and 5 years. Confounding by indication was investigated by considering the relation of asthma to antibiotic use while controlling for the number of illness visits to a physician in early life. RESULTS: There was no statistically significant relation of early antibiotic use with physician-diagnosed eczema or allergen-specific IgE. A dose-response relation was evident for antibiotic use with ever asthma (odds ratio [OR]=1.5, P=0.047). Ever asthma also increased significantly with the number of illness visits to a physician (P<0.001). After adjustment for number of illness visits, antibiotic use showed no relation with asthma. CONCLUSIONS: The relation of asthma to antibiotics in this cohort appears to be an artefact of the strong relation of number of physician visits for illness with both antibiotic use and risk for asthma.

Chronic bronchitis before age 50 years predicts incident airflow limitation and mortality risk.

BACKGROUND: Previous studies on the relationship of chronic bronchitis to incident airflow limitation and all-cause mortality have provided conflicting results, with positive findings reported mainly by studies that included populations of young adults. This study sought to determine whether having chronic cough and sputum production in the absence of airflow limitation is associated with onset of airflow limitation, all-cause mortality and serum levels of C-reactive protein (CRP) and interleukin-8 (IL-8), and whether subjects' age influences these relationships. METHODS: 1412 participants in the long-term Tucson Epidemiological Study of Airway Obstructive Disease who at enrolment (1972-1973) were 21-80 years old and had FEV(1)/FVC (forced expiratory volume in 1 s/forced vital capacity) > or = 70% and no asthma were identified. Chronic bronchitis was defined as cough and phlegm production on most days for > or = 3 months in two or more consecutive years. Incidence of airflow limitation was defined as the first follow-up survey with FEV(1)/FVC <70%. Serum IL-8 and CRP levels were measured in cryopreserved samples from the enrolment survey. RESULTS: After adjusting for covariates, chronic bronchitis at enrolment significantly increased the risk for incident airflow limitation and all-cause mortality among subjects <50 years old (HR 2.2, 95% CI 1.3 to 3.8; and HR 2.2, 95% CI 1.3 to 3.8; respectively), but not among subjects > or = 50 years old (HR 0.9, 95% CI 0.6 to 1.4; and HR 1.0, 95% CI 0.7 to 1.3). Chronic bronchitis was associated with increased IL-8 and CRP serum levels only among subjects <50 years old. CONCLUSIONS: Among adults <50 years old, chronic bronchitis unaccompanied by airflow limitation may represent an early marker of susceptibility to the effects of cigarette smoking on systemic inflammation and long-term risk for chronic obstructive pulmonary disease and all-cause mortality.

Femtosecond absorption dynamics in glass-metal nanocomposites.

We report strong optical nonlinearity of glasses embedded with copper and silver nanoparticles. In pump-probe experiments with copper-doped glasses, the observed absorption bleaching with picosecond relaxation time is as high as 22%. Transmission femtosecond measurementsreveal the reverse saturable absorption with nonlinear absorption coefficient of 10(-10)cm/W in both copper- and silver-doped nanocomposites.

The impact of CD14 polymorphisms on the development of soluble CD14 levels during infancy.

CD14 is a receptor involved in the recognition of lipopolysaccharide and other bacterial wall components that may be involved in the balance between infectious and allergic disease and the early polarization towards TH1. Our group has shown an association between polymorphisms in the 5' flanking region of the CD14 gene and plasma soluble CD14 (sCD14) levels at 11 years of age. However, whether this association is present at birth and in infancy remains to be determined. In this study, we measured sCD14 levels in plasma from the umbilical cord (n = 387) and at 3 months (n = 357) and 1 year (n = 312) of age in non-selected healthy infants to assess their relationship with CD14 genotypes at -4190, -2838, -1720 and -260 (relative to translation start site). There was no relation of CD14 genotypes with sCD14 at birth. However, there was a significant association between CD14 genotypes and sCD14 as early as 3 months. Longitudinal analysis suggests that CD14 polymorphisms modulate sCD14 levels up to 1 year of age. This association early in life may have an impact on TH1 polarization and subsequent protection against allergic disease.

Dynamic changes in sensitization to specific aeroallergens in children raised in a desert environment.

BACKGROUND: Allergen skin test reactivity and total serum IgE are objective measures used to characterize and help diagnose allergic diseases. Cross-sectional studies have shown that overall aeroallergen skin test reactivity increases throughout childhood. However, little attention has been paid to whether individual aeroallergen remittance occurs, which could distort or mask relationships to disease. OBJECTIVE: To access the incidence and remittance of skin test reactions to individual allergens in children aged 6-11 years. METHODS: Longitudinal sensitization to six aeroallergens and total IgE were assessed in 828 children raised in the semi-arid US southwest at ages 6 and 11 years. RESULTS: New sensitization (to any allergen) between 6 and 11 years occurred in 30.2% of children compared with 39.7% before age 6 years. The rate of complete remittance from positive to negative between ages 6 and 11 years was 8.2%, and total IgE at age 6 years was not predictive. Remittance rates for individual allergens were high and variable (19-49%). The perennial allergens Bermuda and Alternaria were early sensitizers and had low remittance rates. Early sensitization to the four seasonal allergens was less common and more subject to remittance with the bulk of sensitization occurring between 6 and 11 years. CONCLUSION: This study shows that sensitization to individual aeroallergens in childhood is dynamic and indicates the limitation of single point assessment of skin test reactivity.

Differential control of eosinophil survival by glucocorticoids.

Glucocorticoids are effective drugs for eosinophil-related disorders, such as asthma and allergy. Previous studies have demonstrated that glucocorticoids increase eosinophil apoptosis and block the survival effect of submaximal concentrations of interleukin-5 (IL-5). We investigated the effect of glucocorticoids on eosinophil survival in the presence of a higher concentration of IL-5 (1 ng/ml), comparable to IL-5 levels in bronchoalveolar lavage and sputum specimens from patients with asthma. In contrast to incubation in the presence of submaximal concentrations of IL-5, the addition of dexamethasone (DEX) to media containing 1 ng/ml IL-5 led to a significant increase in eosinophil cell viability from 58 +/- 6.9% to 87 +/- 2.4% ( p < 0.005) after 72 hours in culture. We found that RU486 blocked the DEX effect on cell viability confirming that glucocorticoid receptor functions are required. We investigated the possibility that the glucocorticoid enhancement of eosinophil survival may be due to an effect on IL-5 receptor expression. Our results show that the IL-5 associated decrease in IL-5 receptor alpha-subunit expression was blocked significantly after 24 hrs in culture with media containing IL-5 plus DEX compared to IL-5 alone. It is tempting to speculate that the observed glucocorticoid enhancement of eosinophil survival in the presence of elevated concentrations of IL-5 could be a mechanism that contributes to glucocorticoid resistance in asthma.

Isolation of high quality RNA from bilberry (Vaccinium myrtillus L.) fruit.

A simple and efficient method is described for isolating high quality RNA from bilberry fruit. The procedure is based on the use of hexadecyltrimethyl ammonium bromide (CTAB), polyvinylpyrrolidone (PVP), and beta-mercaptoethanol in an extraction buffer in order to eliminate the polysaccharides and prevent the oxidation of phenolic compounds. This method is a modification of the one described for pine trees, and yields high-quality RNA suitable for cDNA based methodologies. This method is applicable for a variety of plant tissues.

Factor analysis of asthma and atopy traits shows 2 major components, one of which is linked to markers on chromosome 5q.

BACKGROUND: A variety of definitions of asthma and atopy traits have been used in genetic studies. The variables used may be correlated, increasing the likelihood of type I error. OBJECTIVE: We sought to clarify and quantify phenotypes that may be characterized by related traits. Principal components and factor analysis were applied to the correlation matrix of asthma and atopy traits before linkage analysis. METHODS: Factor analysis was performed on 468 Hispanic and non-Hispanic white children enrolled in the Tucson Children's Respiratory Study, with complete information on 24 items, including skin test response to 7 allergens, total serum IgE levels, presence or absence of asthma attacks, wheezing episodes, hay fever, and cough. Factor score coefficients were then applied to all siblings (n = 877), and quantitative factor scores were derived. Single-point and multipoint nonparametric sib-pair analyses were performed to assess linkage to markers on chromosome 5q31-33. Analyses were also performed for individual items. RESULTS: Two main factors were identified: Factor I had high loadings on atopic items, including skin test responses, IgE, and hay fever, and Factor II had high loadings that included asthma diagnosis, wheezing, cough, and Alternaria species skin test response. Factors I and II were correlated at an r value of 0.19. For the quantitative factor scores, significant single-point linkage (P < .0001) was demonstrated only for atopic Factor I, and a peak multipoint LOD score of 2.7 was seen for marker D5S479. Multipoint LOD scores for individual items were 1.1 or less. CONCLUSION: These analyses suggest evidence for a locus or loci mapping to chromosome 5q31-33 associated with this composite atopic phenotype.

A common single nucleotide polymorphism in the CD14 promoter decreases the affinity of Sp protein binding and enhances transcriptional activity.

CD14 is a pattern recognition receptor that plays a central role in innate immunity through recognition of bacterial lipoglycans, primarily LPS. Recently, our group has identified a common single nucleotide polymorphism, -159C-->T, in the CD14 proximal promoter. Homozygous carriers of the T allele have a significant increase in soluble CD14, but a decreased total serum IgE. This epidemiologic evidence led us to investigate the molecular basis for the effects of CD14/-159C-->T on CD14 regulation in monocytes and hepatocytes, the two major cell types known to express this gene in vivo. EMSA analysis showed that the T allele results in decreased affinity of DNA/protein interactions at a GC box that contains a binding site for Sp1, Sp2, and Sp3 transcription factors. In reporter assays, the transcriptional activity of the T allele was increased in monocytic Mono Mac 6 cells, which express low levels of Sp3, a member of the Sp family with inhibitory potential relative to activating Sp1 and Sp2. By contrast, both alleles were transcribed equivalently in Sp3-rich hepatocytic HepG2 cells. Our data indicate that the interplay between CD14 promoter affinity and the [Sp3]:[Sp1 + Sp2] ratio plays a critical mechanistic role in regulating transcription of the two CD14 alleles. Variation in a key gene of innate immunity may be important for the pathogenesis of allergy and inflammatory disease through gene-by-gene and/or gene-by-environment interactions.

Relation between infantile colic and asthma/atopy: a prospective study in an unselected population.

OBJECTIVE: To assess whether children with history of infantile colic may be at increased risk of subsequently developing asthma and/or atopy. METHODS: We used data collected in a large, prospective study from an unselected population. Infantile colic and concurrent feeding method were determined from the 2-month well-infant visit form completed by the physician for 983 children who were enrolled at birth. Markers of atopy (total serum immunoglobulin E and allergy skin prick test), allergic rhinitis, asthma, wheezing, and peak flow variability were the main outcome measures studied at different ages between infancy and 11 years. RESULTS: Ninety (9.2%) children had infantile colic. Prevalence of colic was similar among children fed either breast milk or formula. There was no association between infantile colic and markers of atopy, asthma, allergic rhinitis, wheezing, or peak flow variability at any age. CONCLUSION: Our data cannot support the hypothesis that infantile colic provides increased risk for subsequent allergic disease or atopy.

CD14: a bridge between innate immunity and adaptive IgE responses.

Total IgE levels are known to be under genetic control. Linkage studies have indicated that one or more loci on chromosome 5q may control total IgE, as well as asthma and bronchial hyperresponsiveness to non-specific stimuli. Our group has undertaken a systematic analysis of chromosome 5q, and has recently characterized five single nucleotide polymorphisms at position -1619, -1359, -1145, -809, and -159 in the promoter of the gene encoding CD14, the myeloid pattern recognition receptor that is critical for efficient innate immune responses to lipopolysaccharide and bacterial ligands. Individuals homozygous for the three major CD14 haplotypes found in the Children Respiratory Study population (n = 390) were analyzed for serum levels of total IgE and soluble CD14. A strong inverse correlation was found between these two parameters, i.e. carriers of the -1359T/-1145A/-159C haplotype had the highest levels of IgE, and the lowest levels of sCD14. Conversely, carriers of the -1359G/-1145G/-159T haplotype had the highest levels of sCD14 and the lowest IgE values. Our results suggest that genetic variation in CD14, a key gene of innate immunity, may modulate the effects that exposure to bacterial ligands has on the development of Th2 responses.

Differences in proliferation of the hematopoietic cell line TF-1 and cytokine production by peripheral blood leukocytes induced by 2 naturally occurring forms of human IL-3.

BACKGROUND: A naturally occurring polymorphism in the coding region of the human IL3 gene leads to a change in amino acid residue 8 from proline to serine. OBJECTIVE: We sought to determine whether the 2 different forms of IL-3 varied in function. These different forms are available as recombinant proteins (recombinant human IL-3/proline 8 [rhIL-3/P8] and recombinant human IL-3/serine 8 [rhIL-3/S8]). METHODS: The erythroleukemic cell line TF-1 was incubated with varying concentrations of rhIL-3/P8 or rhIL-3/S8 to determine the capacity of each type of IL-3 to induce proliferation. Human leukocytes were primed with rhIL-3/P8 or rhIL-3/S8 for up to 24 hours and then stimulated with anti-IgE and assessed for leukotrienes (LTs), IL-4, and TNF-alpha. RESULTS: Proliferation of TF-1 cells was induced by both forms of IL-3 at 48 and 72 hours but to a greater degree by rhIL-3/P8. In contrast, the mean fold increase over control values of LT and IL-4 production was higher after priming the cells with rhIL-3/S8 versus rhIL-3/P8. Additionally, TNF-alpha production was greater (and reached significance only) for rhIL-3/S8. This activity was independent of IgE and thus directly stimulated by IL-3. Studies with basophil-enriched and basophil-depleted cell preparations revealed that LT production was evident only from the former and TNF-alpha only from the latter. CONCLUSION: We conclude that the 2 naturally occurring forms of human IL-3 have similar spectra of activities on cells with IL-3 receptors, but the 2 forms have reversed relative efficacies for promoting proliferation (rhIL-3/P8 > rhIL-3/S8) compared with priming or inducing mediator secretion (rhIL-3/S8 > rhIL-3/P8).

Relation of two different subtypes of croup before age three to wheezing, atopy, and pulmonary function during childhood: a prospective study.

OBJECTIVE: Some retrospective evidence suggests that children with a history of croup may be at increased risk of subsequently developing asthma, atopy, and diminished pulmonary function. The objective of this study was to determine the long-term outcome of croup (as diagnosed by a physician) in early life. METHODS: Lower respiratory illnesses (LRIs) in the first 3 years of life were assessed in 884 children who were enrolled in a large longitudinal study of airway diseases at birth. Pulmonary function tests, markers of atopy, and wheezing episodes were studied at different ages between birth and 13 years. RESULTS: Ten percent of children had croup with wheeze (Croup/Wheeze), 5% had croup without wheeze (Croup/No Wheeze), 36% had another LRI (Other LRI), and 48% had no LRI. Respiratory syncytial virus was more frequently isolated in children with Croup/Wheeze and Other LRI than in those with Croup/No Wheeze. There was no association between croup in early life and markers of atopy measured during the school years. Only children with Croup/Wheeze and with Other LRI had a significant risk of subsequent persistent wheeze later in life. Significantly lower levels of indices of intrapulmonary airway function were observed at ages <1 (before any LRI), 6, and 11 years in children with Croup/Wheeze and Other LRI compared with children with No LRI. Conversely, inspiratory resistance before any LRI episode was significantly higher in infants who later developed Croup/No Wheeze than in the other 3 groups. CONCLUSIONS: We distinguish 2 manifestations of croup with and without wheezing. Children who present with croup may or may not be at increased risk of subsequent recurrent lower airway obstruction, depending on the initial lower airway involvement, and preillness and postillness abnormalities in lung function associated with this condition.

Autoimmune polyendocrine syndrome type 1 (APS I) in Norway.

OBJECTIVE: The aim of the present study was to investigate Norwegian patients with autoimmune polyendocrine syndrome type I (APS I), with respect to occurrence and clinical presentation, reactivity towards different autoantigenes and mutations in the autoimmune regulator (AIRE) gene. PATIENTS: Twenty Norwegian patients from 15 families with APS I (11 males, nine females; mean age 26 years, range 4--54) were included by contacting all major hospitals in Norway. METHODS: Clinical data was collected from both patients and their physicians by the use of questionnaires and patient records. Autoantibodies were analysed using radioimmunoassays based on antigen synthesized by in vitro transcription and translation. AIRE mutations were determined by DNA sequence analysis. RESULTS: The prevalence of APS I in Norway was estimated to be about 1 : 80,000 individuals. We found about the same distribution of disease characteristics as has been reported in Finnish patients. The diagnosis was delayed in many individuals. In two thirds of the cases, the patients were admitted in Hospital with acute adrenal insufficiency or hypocalcaemic crisis. Forty percent of these patients already had one of the main disease manifestations. Four different mutations in the AIRE gene were found in the Norwegian cohort. A 13-bp deletion in exon 8 (1085--1097(del)) was the most frequent mutation, present in 22/40 (55%) of the alleles. Eighty-five percent of the patients had either autoantibodies against 21 hydroxylase or aromatic L-amino acid decarboxylase. Five of eight women (age > 13 years) had ovarian failure, and all of these had antibodies against side-chain cleavage enzyme (P = 0.0002). CONCLUSION: Norwegian patients with APS I clinically resemble patients from Finland and other European countries. The diagnosis APS I must be considered in children and adolescents with chronic mucocutaneous candidiasis, autoimmune adrenocortical failure or hypoparathyroidism in order to avoid fatal complications. Analysis of autoantibodies and mutational analysis of the AIRE gene are valuable diagnostic tools, especially in the early stages of the disease.

Subcellular location and expression pattern of autoimmune regulator (Aire), the mouse orthologue for human gene defective in autoimmune polyendocrinopathy candidiasis ectodermal dystrophy (APECED).

Autoimmune polyendocrinopathy candidiasis ectodermal dystrophy (APECED), also known as autoimmune polyglandular syndrome Type I (APS1), is an autosomal recessive autoimmune disease caused by mutations in a gene designated as AIRE (autoimmune regulator). Here we have studied the expression of Aire in transfected cell lines and in adult mouse tissues. Our results show that Aire has a dual subcellular location and that it is expressed in multiple immunologically relevant tissues such as the thymus, spleen, lymph nodes, and bone marrow. In addition, Aire expression was detected in various other tissues such as kidney, testis, adrenal glands, liver, and ovary. These findings suggest that APECED protein might also have a function(s) outside the immune system.(J Histochem Cytochem 49:197-208, 2001)

The autoimmune regulator: a key toward understanding the molecular pathogenesis of autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy.

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is an autoimmune disease with autosomal recessive inheritance. APECED is characterized by the breakdown of tolerance to several organ-specific selfantigens. The symptoms of APECED fall into three main categories: autoimmune polyendocrinopathies, chronic mucocutaneous candidiasis, and ectodermal dystrophies. The gene defective in APECED, AIRE, has been cloned and numerous mutations in this gene have been found in patients with APECED. AIRE is predicted to encode a 545-amino-acid protein containing structural domains characteristic for transcription regulators. The protein has been shown to act as a transcriptional activator in vitro. The AIRE protein is mainly localized to the nucleus, where it can be detected as speckles resembling nuclear bodies. In humans, the expression of AIRE has been observed predominantly in immunologically relevant tissues, especially the thymus. Recently, we have shown in the mouse that Aire is also expressed in various tissues and cell types outside the immune system.

The association of allergic sensitization in mother and child in breast-fed and formula-fed infants.

Human milk contains immunologically active substances potentially capable of altering infant immune response. As part of the prospective Children's Respiratory Study, we assessed whether the association between maternal allergic status and allergic status of the child was altered by breast-feeding. Skin-prick tests for 7 common allergens were administered to 702 6-year-old children and their mothers. The percentage of children sensitized to specific allergens, maternal skin test response to that allergen, and whether or not the child was ever breast-fed was determined. Findings indicated that specific sensitization in the mother was associated with specific sensitization in the child only if the child was breast-fed. This indirectly supports the hypothesis that contents of milk differ with maternal allergic status, and appear to affect allergic status in the child. These results suggest that milk from allergic mothers either promotes a Th2 type immune response or suppresses Th1 immune response in the child.

Workshop to identify critical windows of exposure for children's health: immune and respiratory systems work group summary.

Fetuses, infants, and juveniles (preadults) should not be considered simply "small adults" when it comes to toxicological risk. We present specific examples of developmental toxicants that are more toxic to children than to adults, focusing on effects on the immune and respiratory systems. We describe differences in both the pharmacokinetics of the developing immune and respiratory systems as well as changes in target organ sensitivities to toxicants. Differential windows of vulnerability during development are identified in the context of available animal models. We provide specific approaches to directly investigate differential windows of vulnerability. These approaches are based on fundamental developmental biology and the existence of discrete developmental processes within the immune and respiratory systems. The processes are likely to influence differential developmental susceptibility to toxicants, resulting in lifelong toxicological changes. We also provide a template for comparative research. Finally, we discuss the application of these data to risk assessment.

A cluster of seven tightly linked polymorphisms in the IL-13 gene is associated with total serum IgE levels in three populations of white children.

BACKGROUND: Increased levels of total serum IgE are a strong risk factor for the development of asthma. IgE is also involved in host defenses against parasites and fungi. Linkage of total serum IgE with markers located close to the 3 Mb cluster of cytokine genes in chromosome 5q31 has been reported. IL-4 or IL-13 are regarded as essential for IgE synthesis. OBJECTIVE: We tested whether polymorphisms in the IL-13 gene might explain the linkage between chromosome 5q31 and total serum IgE levels. METHODS: We used denaturing HPLC to detect polymorphisms in overlapping PCR fragments of the IL-13 gene including promoter and 3' untranslated regions. After sequencing was performed to identify the locations of the polymorphisms, PCR and primer-induced restriction site assays were used to genotype subjects in 3 unselected populations. RESULTS: We report here 7 polymorphisms (6 novel) in IL-13. Four of these polymorphisms are tightly linked to a variant in the terminal portion of the coding region of the gene that results in a predicted amino acid change in residue 130 (Arg130Gln). The Gln form is strongly associated (P =.000002) with increased serum IgE levels in 3 different populations comprising a total of 1399 children. Two additional polymorphisms in the promoter region of IL-13 are more loosely linked to Arg130Gln and are also less significantly associated with total serum IgE levels. CONCLUSION: These data suggest that the Arg130Gln polymorphism in IL-13, or others in close linkage with it, is associated with the development of the elevated serum IgE phenotype.