Association Between Antibiotic Exposure, Bronchiolitis, and TLR4 (rs1927911) Polymorphisms in Childhood Asthma

Purpose

The complex interplay between environmental and genetic factors plays an important role in the development of asthma. Several studies have yielded conflicting results regarding the 2 asthma-related risk factors: antibiotic usage during infancy and/or a history of bronchiolitis during early life and the development of asthma. In addition to these risk factors, we also explored the effects of Toll-like receptor 4 (TLR4) polymorphism on the development of childhood asthma.

Methods

This cross-sectional study involved 7,389 middle school students who were from 8 areas of Seoul, Korea, and completed the International Study of Asthma and Allergies in Childhood questionnaire. The TLR4 polymorphism rs1927911 was genotyped in 1,395 middle school students from two areas using the TaqMan assay.

Results

Bronchiolitis in the first 2 years of life, antibiotic exposure during the first year of life, and parental history of asthma were independent risk factors for the development of asthma. When combined, antibiotic use and a history of bronchiolitis increased the risk of asthma (adjusted odds ratio [aOR]: 4.64, 95% confidence interval [CI]: 3.09-6.97, P value for interaction=0.02). In subjects with CC genotype of TLR4, antibiotic exposure and a history of bronchiolitis during infancy, the risk of asthma was increased, compared to subjects without these risk factors (aOR: 5.72, 95% CI: 1.74-18.87).

Conclusions

Early-life antibiotic exposures and a history of bronchiolitis are risk factors for asthma in young adolescents. Polymorphisms of TLR4 modified the influence of these environmental factors. Reducing antibiotic exposure and preventing bronchiolitis during infancy may prevent the development of asthma, especially in genetically susceptible subjects.

The relationship between asthma and bronchiolitis is modified by TLR4, CD14, and IL-13 polymorphisms

BACKGROUND

Asthma is a complex genetic disorder that is associated with both genetic and environmental factors. The aim of study was to investigate the combined effect of toll-like receptor 4 (TLR4), cluster of differentiation 14 (CD14), and interleukin-13 (IL-13) polymorphisms and bronchiolitis in the development of childhood asthma.

METHODS

A modified International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire was used to survey 1,341 elementary school children and 919 nursery children in Seoul, Korea. TLR4 (rs1927911), CD14 (rs2569190), and IL-13 (rs20541) polymorphisms were genotyped by the TaqMan assay.

RESULTS

In elementary school and nursery children, parental history of asthma (adjusted odds ratio [aOR] 2.56 [95% CI 1.16-5.63], aOR 3.60 [95% CI 1.66-7.76], respectively), and past history of bronchiolitis (aOR 3.11 [95% CI 1.84-5.24], aOR 3.94 [95% CI 2.27-6.84], respectively) were independent risk factors for asthma diagnosis. When compared to children with each CC of TLR4 polymorphism or TT of CD14 polymorphism or GG of IL13 polymorphism and no past history of bronchiolitis, children with CT or TT of TLR4 polymorphism and past history of bronchiolitis had 4.23 and 5.34 times higher risk to develop asthma, respectively; children with TT of CD14 polymorphism and past history of bronchiolitis had 3.57 and 7.22 times higher risk for asthma, respectively; children with GA or AA of IL-13 polymorphism and past history of bronchiolitis had 3.21 and 4.13 times higher risk for asthma, respectively.

CONCLUSIONS

Family history of asthma or allergic rhinitis and past history of bronchiolitis could be independent risk factors for the development of childhood asthma. The relationship between asthma and bronchiolitis is modified by the TLR4, CD14, and IL-13 polymorphisms in Korean children.

The effect of perinatal anxiety on bronchiolitis is influenced by polymorphisms in ROS-related genes

Background

Exposure to perinatal anxiety affects disease susceptibility in offspring but studies on the association between perinatal anxiety and gene polymorphisms are lacking. This study aimed to elucidate the interaction between perinatal anxiety and polymorphisms in antioxidant defense and innate immunity genes on the development of respiratory tract infections (RTIs) during early infancy.

Methods

Trait anxiety levels in 440 women were assessed by the State-Trait Anxiety Inventory during late gestation. The occurrence of RTIs, including bronchiolitis, during the first year of life was assessed by parent-reported doctor diagnosis. Polymorphisms in glutathione S-transferase P-1 (GSTP1, rs1695) and CD14 (rs2569190) were genotyped using the TaqMan assay. Copy number variations of GSTT1 were measured by real-time polymerase chain reaction.

Results

Exposure to high levels of perinatal anxiety increased the risk of bronchiolitis in the first year of life (adjusted odds ratio [aOR], 1.30; 95% confidence interval [CI]: 1.00–1.80), in particular among children with the AG + GG genotype of GSTP1 or the GSTT1 null genotype (aOR 3.36 and 2.79). In infants with the TC + CC genotype of CD14, high levels of perinatal anxiety were associated with an increased risk of upper RTI, lower RTI, and bronchiolitis (aOR 2.51, 4.60, and 4.31, respectively).

Conclusions

Perinatal maternal anxiety levels affect the occurrence of bronchiolitis in offspring. The effect of perinatal anxiety on the occurrence of bronchiolitis during infancy was influenced by genetic polymorphisms in antioxidant defense and innate immunity genes.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2466-14-154) contains supplementary material, which is available to authorized users.

Clinical application of exhaled nitric oxide measurements in a korean population

Nitric oxide (NO) is a biologic mediator of various physiologic functions. Recent evidence suggests the clinical utility of fractional exhaled NO (FeNO) as a biomarker for assessing asthma and other respiratory diseases. FeNO methodologies have been recently standardized by international research groups and subsequently validated in several Korean population studies. Normal ranges for FeNO have been reported for various ethnic groups, and the clinical utility has been widely evaluated in asthma and various respiratory diseases. Based on current evidence including most of Korean population data, this position paper aims to introduce the methodological considerations, and provide the guidance for the proper clinical application of FeNO measurements in Korean populations.

Effect of antibiotic use and mold exposure in infancy on allergic rhinitis in susceptible adolescents

BACKGROUND

Antibiotic use in infancy induces alteration in intestinal microbiota and is associated with the development of allergic diseases. Mold exposure is also associated with allergic diseases. Genetic susceptibility may interact with specific environmental factors in allergic disease development.

OBJECTIVE

To investigate independent and combined effects of antibiotic use and mold exposure in infancy on the risk of allergic rhinitis (AR) in adolescents.

METHODS

Data on AR and environmental factors were collected using the International Study of Asthma and Allergies in Childhood questionnaire from 7,389 adolescents from Seoul, Korea. TaqMan genotyping was performed for interleukin 13 (IL-13) (rs20541) and Toll-like receptor 4 (rs1927911) polymorphisms in 1,395 adolescents.

RESULTS

Age, parental history of AR, antibiotic use in infancy, and pet ownership during pregnancy or infancy were associated with an increased risk of current AR (diagnosis of AR and symptoms of AR within the preceding 12 months). Having older siblings was a protective effect. The adjusted odds ratio (aOR) for current AR for combined antibiotic use and mold exposure in infancy was 1.45 (95% confidence interval [CI], 1.01-2.09). For each factor separately, aORs were 1.25 (95% CI, 1.04-1.50) and 0.99 (95% CI, 0.75-1.31), respectively. Antibiotic and mold exposure in infancy, GA or AA genotypes of IL-13 (rs20541) (aOR 4.53; 95% CI, 1.66-12.38; P for interaction = .05), and CT+TT genotype of Toll-like receptor 4 (rs1927911) (aOR, 3.20; 95% CI, 1.24-8.26; P for interaction = .18) increased the risk of current AR.

CONCLUSION

Antibiotic use and mold exposure in infancy have additive effects on the risk of current AR in genetically susceptible adolescents. Gene-environment interactions between IL-13 (rs20541) and antibiotics or mold may play a role in AR.

Additive effect between IL-13 polymorphism and cesarean section delivery/prenatal antibiotics use on atopic dermatitis: a birth cohort study (COCOA)

Background

Although cesarean delivery and prenatal exposure to antibiotics are likely to affect the gut microbiome in infancy, their effect on the development of atopic dermatitis (AD) in infancy is unclear. The influence of individual genotypes on these relationships is also unclear. To evaluate with a prospective birth cohort study whether cesarean section, prenatal exposure to antibiotics, and susceptible genotypes act additively to promote the development of AD in infancy.

Methods

The Cohort for Childhood of Asthma and Allergic Diseases (COCOA) was selected from the general Korean population. A pediatric allergist assessed 412 infants for the presence of AD at 1 year of age. Their cord blood DNA was subjected to interleukin (IL)-13 (rs20541) and cluster-of-differentiation (CD)14 (rs2569190) genotype analysis.

Results

The combination of cesarean delivery and prenatal exposure to antibiotics associated significantly and positively with AD (adjusted odds ratio, 5.70; 95% CI, 1.19–27.3). The association between cesarean delivery and AD was significantly modified by parental history of allergic diseases or risk-associated IL-13 (rs20541) and CD14 (rs2569190) genotypes. There was a trend of interaction between IL-13 (rs20541) and delivery mode with respect to the subsequent risk of AD. (P for interaction = 0.039) Infants who were exposed prenatally to antibiotics and were born by cesarean delivery had a lower total microbiota diversity in stool samples at 6 months of age than the control group. As the number of these risk factors increased, the AD risk rose (trend p<0.05).

Conclusion

Cesarean delivery and prenatal antibiotic exposure may affect the gut microbiota, which may in turn influence the risk of AD in infants. These relationships may be shaped by the genetic predisposition.

Association between recent acetaminophen use and asthma: modification by polymorphism at TLR4

The risk of asthma has been increasing in parallel with use of acetaminophen, which is a potential source of oxidative stress. Toll-like receptor 4 (TLR4) plays a critical role not only in innate immunity, but also in mediating reactive oxygen species induced inflammation. Therefore, we investigated associations between acetaminophen usage and TLR4 polymorphism on asthma and bronchial hyperresponsiveness (BHR). The number of 2,428 elementary school children in Seoul and Jeongeup cities was recruited. Subjects who used acetaminophen with a family history of asthma had an increased risk of both asthma diagnosis ever and current asthma. Individuals with CT+TT genotypes at the TLR4 polymorphism, in combination with acetaminophen usage, also demonstrated an increased risk of asthma diagnosis ever (aOR, 2.08; 95% confidence interval [CI], 1.10-3.92). Family history of asthma and acetaminophen usage were risk factors for BHR. Although TLR4 was not an independent risk factor for BHR, individuals with CT+TT genotypes at the TLR4 polymorphism had an increased risk of BHR when combined with acetaminophen usage (aOR, 1.74; 95% CI, 1.03-2.94). In conclusion, acetaminophen usage may be associated with asthma and BHR in genetically susceptible subjects. This effect may be modified by polymorphism at TLR4.

Reference values and determinants of fractional concentration of exhaled nitric oxide in healthy children

Purpose

Measurement of the fractional concentration of exhaled nitric oxide (FeNO) is a quantitative, noninvasive, simple, safe method of assessing airway inflammation. While FeNO measurement has been standardized, reference values for elementary school children are scarce. The aim of this study was to establish reference values for FeNO in children.

Methods

FeNO was measured in elementary school children at 6-12 years of age in Seoul, Korea, following American Thoracic Society guidelines and using a chemiluminescence analyzer (NIOX Exhaled Nitric Oxide Monitoring System, Aerocrine, Sweden). A total of 1,252 children completed a modified International Study of Asthma and Allergy in Children (ISAAC) questionnaire; FeNO was measured in 1,063 children according to the protocol and in 808 children defined as healthy controls.

Results

Mean FeNO were 10.32 ppb, 16.58 ppb, and 12.36 ppb in non-atopic, atopic, and all 808 healthy controls, respectively. FeNO was not associated with age and gender. The FeNO reference equations were determined by multiple linear regression analysis, taking into account the variables of age, height, weight, total IgE, eosinophil percent, and bronchial hyper-responsiveness (methacholine PC20). FeNO=0.776+0.003×total IgE+0.340×eosinophil percent; coefficient of determination (R2)=0.084 in the 501 healthy non-atopic controls. FeNO=-18.365+1.536×eosinophil percent, R2=0.183 in the 307 healthy atopic controls; and FeNO=-7.888+0.130×Height+0.004×total IgE+1.233×eosinophil percent, R2=0.209 in the 808 all healthy controls. Eosinophil percent was correlated with FeNO in all healthy controls. FeNO was not associated with BMI.

Conclusion

This study provides reference values for FeNO that can be used to evaluate airway inflammation in elementary school children. Determinants that could most accurately predict FeNO in healthy school-age children were assessed.

Generalized joint hypermobility in healthy female koreans: prevalence and age-related differences

OBJECTIVE

Objective To evaluate the prevalence of generalized joint hypermobility (GJH) in healthy female Koreans and to determine whether the degree of GJH differs between children and adults.

METHODS

Two groups of females were enrolled, a group of girls from an elementary school (n=404) and women from a call center (n=266). GJH was diagnosed using the Beighton score, which is composed of an evaluation of bilateral knees, elbows, thumbs, and fifth fingers as well as thoracolumbar joint. The GJH and localized hypermobility of each joint was compared between the two groups, and the pattern of hypermobility according to age and dominant hand was investigated.

RESULTS

Total prevalence of GJH was 50.0% (335/750), and it was more frequently observed in the group of girls (58.9%, 238/404) than women (36.5%, 97/266). The degree of GJH expressed in terms of Beighton score was inversely correlated with age (p<0.05). Significant differences in localized hypermobility of the thumb and fifth finger were found between the two groups and were postulated as the cause for the decline in GJH with age. The pattern of decreased mobility proportional to aging differed between the two joints. Decreased mobility occurred equally on both sides of the thumb but was biased toward the fifth finger of the dominant side (mostly the right).

CONCLUSION

The female Koreans appeared to have a high prevalence of GJH. The incidence of GJH decreased as age increased as a result of decreased mobility of the fifth finger on the dominant side.

Association between cord blood 25-hydroxyvitamin D concentrations and respiratory tract infections in the first 6 months of age in a Korean population: a birth cohort study (COCOA)

PURPOSE

Previous studies suggest that the concentration of 25-hydroxyvitamin D [25(OH)D] in cord blood may show an inverse association with respiratory tract infections (RTI) during childhood. The aim of the present study was to examine the influence of 25(OH)D concentrations in cord blood on infant RTI in a Korean birth cohort.

METHODS

The levels of 25(OH)D in cord blood obtained from 525 Korean newborns in the prospective COhort for Childhood Origin of Asthma and allergic diseases were examined. The primary outcome variable of interest was the prevalence of RTI at 6-month follow-up, as diagnosed by pediatricians and pediatric allergy and pulmonology specialists. RTI included acute nasopharyngitis, rhinosinusitis, otitis media, croup, tracheobronchitis, bronchiolitis, and pneumonia.

RESULTS

The median concentration of 25(OH)D in cord blood was 32.0 nmol/L (interquartile range, 21.4 to 53.2). One hundred and eighty neonates (34.3%) showed 25(OH)D concentrations less than 25.0 nmol/L, 292 (55.6%) showed 25(OH)D concentrations of 25.0-74.9 nmol/L, and 53 (10.1%) showed concentrations of ≥75.0 nmol/L. Adjusting for the season of birth, multivitamin intake during pregnancy, and exposure to passive smoking during pregnancy, 25(OH)D concentrations showed an inverse association with the risk of acquiring acute nasopharyngitis by 6 months of age (P for trend=0.0004).

CONCLUSION

The results show that 89.9% of healthy newborns in Korea are born with vitamin D insufficiency or deficiency (55.6% and 34.3%, respectively). Cord blood vitamin D insufficiency or deficiency in healthy neonates is associated with an increased risk of acute nasopharyngitis by 6 months of age. More time spent outdoors and more intensified vitamin D supplementation for pregnant women may be needed to prevent the onset of acute nasopharyngitis in infants.

Thermal imaging comparison of Signature, Infiniti, and Stellaris phacoemulsification systems

Background

To compare the heat production of 3 different phacoemulsification machines under strict laboratory test conditions. More specifically, the thermal behavior was analyzed between the torsional modality of the Infiniti system and longitudinal modalities of the Abbot WhiteStar Signature Phacoemulsification system and Bausch and Lomb Stellaris system.

Methods

Experiments were performed under in-vitro conditions in this study.

Three phacoemulsification handpieces (Infiniti, Signature, and Stellaris) were inserted into balanced salt solution-filled silicone test chambers and were imaged side-by-side by using a thermal camera. Incision compression was simulated by suspending 30.66-gram weights from the silicone chambers. The irrigation flow rate was set at 0, 1, 2, 3, 4, and 5 cc/min and the phacoemulsification power on the instrument consoles was set at 40, 60, 80, and 100%. The highest temperatures generated from each handpiece around the point of compression were measured at 0, 10, 30, and 60 seconds.

Results

Under the same displayed phacoemulsification power settings, the peak temperatures measured when using the Infiniti were lower than when using the other two machines, and the Signature was cooler than the Stellaris. At 10 seconds, torsional phacoemulsification with Infiniti at 100% power showed data comparable to that of the Signature at 80% and the Stellaris at 60%. At 30 seconds, the temperature from the Infiniti at 100% power was lower than the Signature at 60% and the Stellaris at 40%.

Conclusions

Torsional phacoemulsification with the Infiniti generates less heat than longitudinal phacoemulsification with the Signature and the Stellaris. Lower operating temperatures indicate lower heat generation within the same fluid volume, which may provide additional thermal protection during cataract surgery.

Simple keratectomy and corneal tattooing for limbal dermoids: results of a 3-year study

AIM

To evaluate and report the efficacy of combined surgical excision and corneal tattooing in patients with limbal dermoids.

METHODS

In a retrospective interventional case series, 9 eyes of 8 patients were treated with combined surgery of simple keratectomy and corneal tattooing for limbal dermoids. Medical records, including best-corrected visual acuity, anterior segment photography, demographic, clinical data, and follow-up information were reviewed.

RESULTS

The mean follow up period in this study was 50±15(range 36-77) months. There was no evidence of infection or recurrent limbal dermoids in any of the eyes during the follow-up period. All patients achieved good cosmetic outcomes with no complications.

CONCLUSION

Simple keratectomy and corneal tattooing of limbal dermoids could be an alternative option for surgery, especially when a donor cornea is not available.

Allergic diseases in preschoolers are associated with psychological and behavioural problems

Purpose

The aim of the present study was to investigate the relationship between three major allergic diseases, asthma, allergic rhinitis (AR), and atopic dermatitis (AD), and psychological and behavioural problems in preschoolers based on a community survey.

Methods

A cross-sectional survey was conducted using a modified International Study of Asthma and Allergies in Childhood questionnaire to determine the prevalence of symptoms and diagnosed allergic diseases, and a Korean version of the Child Behaviour Checklist to assess internalizing, externalizing, and sleep problems among 780 preschoolers. Five-hundred and seventy-five preschoolers with valid data were included in this study.

Results

The prevalence of lifetime diagnosis and treatment in the past 12 months was 8.7% and 4.4% for asthma, 24.4% and 19.2% for AR, and 35.1% and 16.6% for AD, respectively. Scores for internalizing and sleep problems were significantly higher in those diagnosed with AR. Preschoolers who had been treated for AD in the past 12 months had higher attention problem and attention-deficit/hyperactivity disorder scores. Sleep problems were more severe in moderate to severe AD compared to control and mild AD groups, categorised according to SCOring index of AD. The severity of sleep problems correlated positively with the percentage of eosinophils in peripheral blood.

Conclusions

Psychological and behavioural problems differed among the three major allergic diseases, weaker association for asthma and stronger association for AR and AD. The results of this study may lead to the identification of potential underlying shared mechanisms common to allergic diseases and psychological and behavioural problems.

Effect of paracetamol use on the modification of the development of asthma by reactive oxygen species genes

BACKGROUND

Recent studies have identified an increase in the prevalence of asthma associated with paracetamol use.

OBJECTIVE

To identify the relationship among asthma, biomarkers, genes, and paracetamol use in preschool children.

METHODS

We undertook a population-based, cross-sectional survey of 933 preschool children. Asthma status was classified according to medical history and asthmatic symptoms. History of paracetamol use in infancy was recorded. Impulse oscillometry, blood tests for eosinophils and total IgE, and genotyping of NAT2, Nrf2, and GSTP1 polymorphisms by TaqMan assay were conducted.

RESULT

Paracetamol use in infancy was associated with an increased risk of treatment for asthma within the previous 12 months. Paracetamol use together with a family history of asthma increased the risk of asthma diagnosis ever, current asthma, and treatment for asthma within the previous 12 months. Gene polymorphisms in NAT2 (rs4271002), Nrf2 (rd6726395), and GSTP1 (rd1695) increased the risk of treatment for asthma within the last 12 months. Eosinophils were significantly elevated in the group with paracetamol use and a family history of asthma; however, the serum total IgE level and IOS did not show any significant difference.

CONCLUSION

Paracetamol use in infancy was significantly associated with increased risk of asthma. The association is more significant in genetically susceptible children, related to antioxidant genes, and the effect may be mediated by eosinophilic inflammation.