Gender-limited association of cytotoxic T-lymphocyte antigen-4 (CTLA-4) polymorphism with cord blood IgE levels

Sex effects in the association between airway microbiome and asthma

BACKGROUND

Sex differences exist in asthma susceptibility and severity. Accumulating evidence has linked airway microbiome dysbiosis to asthma, and airway microbial communities have been found to differ by sex. However, whether sex modifies the link between airway microbiome and asthma has not been investigated.

OBJECTIVE

To evaluate sex effects in the association between airway microbiome and asthma.

METHODS

We analyzed induced sputum samples from 47 subjects (n = 23 patients with asthma and n = 24 normal controls) using 16S ribosomal RNA gene sequencing methods. The bacterial composition was analyzed for sex differences. Bacterial associations with asthma were assessed for each sex at the core taxa and genus levels.

RESULTS

The microbiome in induced sputum differed in women vs men at the community level. A total of 5 core bacterial taxa were found in all samples. No sex-specific core taxa were detected. The most abundant core taxon, Streptococcus salivarius, was significantly enriched in women than in men (P = .02). Within each sex, individuals with relatively lower abundance of S salivarius were more likely to have asthma (P = .006). For both sexes, increased Lactobacillus species were found in sputum samples of patients with patients compared with normal controls (adjusted P = .01). Haemophilus species were associated with asthma in men and not in women.

CONCLUSION

The airway microbiome differed by sex, and sex effects exist in the association of airway microbial markers and asthma. Future airway microbiome studies may yield better resolution if the context of specific sex is considered. The airway microbiome is a potential mechanism driving sex differences in asthma.

Respiratory resistance among adults in a population-based cohort study in Northern Japan

BACKGROUND

Forced oscillation technique (FOT) is a noninvasive method used to measure respiratory system resistance (Rrs) and reactance (Xrs) during quiet breathing, which has been extensively studied in clinical settings. The distribution of measured FOT values was previously assessed in a community-based cohort study. In this study, we aimed to confirm the distribution of measured FOT values in a different cohort in order to investigate the relationship between these values and patient clinical and biological data.

METHODS

We reviewed FOT data and relevant patient clinical and biological information collected from the Community-Based Cohort Study (CommCohort Study), carried out between 2013 to 2016 as a part of the Tohoku Medical Megabank project (TMM). In total, 16,231 adults were enrolled in the study (Male/Female: 4886/11,345).

RESULTS

Significant gender differences were observed in distributions of Rrs and Xrs values at 5 Hz (termed R5 and X5, respectively). R5 values in males were lower than those in females, while X5 values in males were slightly less negative. High R5 values were strongly associated with high BMI, short height, smoking status in males, high serum IgE level, and high peripheral blood eosinophil count.

CONCLUSION

The present distribution values and their relation to clinical and biological data should provide useful insights for clinical settings and serve as a helpful guide in implementing FOT. Forced oscillation technique, respiratory system resistance, respiratory system reactance, gender difference, obesity.

Determinants of sensitization to allergen in infants and young children

Atopic sensitization is a complex phenomenon that changes dynamically with age throughout childhood; its prevalence increases with age in young children. Additionally, with increasing age, the prevalence of sensitization to inhalant allergens and the prevalence of polysensitization to allergens increase. It is also well established that the development of atopic sensitization is the result of a complex interplay of genetic and environmental factors. However, there is considerable heterogeneity in the literature in terms of the effect of different environmental exposures in young children on the subsequent risk of atopic sensitization and allergic diseases. Previous studies on the relationship, in early life, between pet ownership, sex, exposure to secondhand smoke, exposure to traffic-related air pollution components, and atopic sensitization have yielded different results. Recent studies have highlighted the importance of gene-environment interactions, especially during early childhood, on the risk of subsequent atopic sensitization and allergic diseases. Therefore, pediatricians should consider the genetic and environmental determinants of atopic sensitization in infants and young children when diagnosing and treating patients with allergic diseases. Determining ways in which early exposure to these risk factors in young children may be reduced could be beneficial in preventing the likelihood of developing atopic sensitization.

Irreversible airway obstruction in asthma: what we lose, we lose early

Asthma, a syndrome manifested by airway inflammation and obstruction, globally contributes significantly to morbidity and mortality. Although current evidence identifies risk factors that evoke asthma, critical questions concerning susceptibility factors that induce severe persistent disease remain unclear. Early onset of asthma decreases lung function that may be unrecognized until later in adulthood when patients experience dyspnea on exertion and attenuated quality of life. This review highlights current evidence in predicting the onset of asthma and identifying those patients at greatest risk for severe persistent disease.

Different genetic associations of the IgE production among fetus, infancy and childhood

Elevation of serum IgE levels has long been associated with allergic diseases. Many genes have been linked to IgE production, but few have been linked to the developmental aspects of genetic association with IgE production. To clarify developmental genetic association, we investigated what genes and gene-gene interactions affect IgE levels among fetus, infancy and childhood in Taiwan individuals. A birth cohort of 571 children with completion of IgE measurements from newborn to 1.5, 3, and 6 years of age was subject to genetic association analysis on the 384-customized SNPs of 159 allergy candidate genes. Fifty-three SNPs in 37 genes on innate and adaptive immunity, and stress and response were associated with IgE production. Polymorphisms of the IL13, and the HLA-DPA1 and HLA-DQA1 were, respectively, the most significantly associated with the IgE production at newborn and 6 years of age. Analyses of gene-gene interactions indentified that the combination of NPSR1, rs324981 TT with FGF1, rs2282797 CC had the highest risk (85.7%) of IgE elevation at 1.5 years of age (P = 1.46×10⁻⁴). The combination of IL13, CYFIP2 and PDE2A was significantly associated with IgE elevation at 3 years of age (P = 5.98×10⁻⁷), and the combination of CLEC2D, COLEC11 and CCL2 was significantly associated with IgE elevation at 6 years of age (P = 6.65×10⁻⁷). Our study showed that the genetic association profiles of the IgE production among fetus, infancy and childhood are different. Genetic markers for early prediction and prevention of allergic sensitization may rely on age-based genetic association profiles.

Prenatal and postnatal probiotics reduces maternal but not childhood allergic diseases: a randomized, double-blind, placebo-controlled trial

BACKGROUND

The prevalence of atopic diseases has increased rapidly in recent decades globally. The administration of probiotics to reduce gastrointestinal inflammation has been popular, but its role in the prevention or treatment of allergic disease remains controversial. This study evaluated the effectiveness of prenatal and postnatal probiotics in the prevention of early childhood and maternal allergic diseases.

METHODS

In a prospective, double-blind, placebo-controlled clinical trial, pregnant women with atopic diseases determined by history, total immunoglobulin (Ig)E > 100 kU/L, and/or positive specific IgE were assigned to receive either probiotics (Lactobacillus GG; ATCC 53103; 1 × 10(10) colony-forming units daily) or placebo from the second trimester of pregnancy. Both of clinical evaluation performed by questionnaires concerning any allergic symptoms and plasma total IgE, and allergen-specific IgE were obtained in high-risk parents and children at 0, 6, 18, and 36 months of age. The primary and secondary outcomes were the point and cumulative prevalence of sensitization and developing of allergic diseases, and improvement of maternal allergic symptom score and plasma immune parameters before and after intervention, respectively.

RESULTS

In total, 191 pregnant women (LGG group, n = 95; control group, n = 96) were enrolled. No significant effects of prenatal and postnatal probiotics supplementation on sensitization, development of allergic diseases, and maternal IgE levels between placebo and LGG groups. Symptoms of maternal allergic scores improved significantly in the LGG group (P = 0.002). Maternal allergic diseases improvement was more prominent in pregnant women with IgE > 100 kU/L (P = 0.01) and significantly associated with higher interleukin-12p70 levels (P = 0.013).

CONCLUSIONS

LGG administration beginning at the second trimester of pregnancy reduced the severity of maternal allergic disease through increment of Th1 response, but not the incidence of childhood allergic sensitization or allergic diseases (ClinicalTrials.govnumber, IDNCT00325273).

Perinatal gene-gene and gene-environment interactions on IgE production and asthma development

Atopic asthma is a complex disease associated with IgE-mediated immune reactions. Numerous genome-wide studies identified more than 100 genes in 22 chromosomes associated with atopic asthma, and different genetic backgrounds in different environments could modulate susceptibility to atopic asthma. Current knowledge emphasizes the effect of tobacco smoke on the development of childhood asthma. This suggests that asthma, although heritable, is significantly affected by gene-gene and gene-environment interactions. Evidence has recently shown that molecular mechanism of a complex disease may be limited to not only DNA sequence differences, but also gene-environmental interactions for epigenetic difference. This paper reviews and summarizes how gene-gene and gene-environment interactions affect IgE production and the development of atopic asthma in prenatal and childhood stages. Based on the mechanisms responsible for perinatal gene-environment interactions on IgE production and development of asthma, we formulate several potential strategies to prevent the development of asthma in the perinatal stage.

Different implications of paternal and maternal atopy for perinatal IgE production and asthma development

Asthma is a hereditary disease associated with IgE-mediated reaction. Whether maternal atopy and paternal atopy have different impacts on perinatal IgE production and asthma development remains unclear. This paper reviews and summarizes the effects of maternal and paternal atopy on the developmental aspects of IgE production and asthma. Maternal atopy affects both pre- and postnatal IgE production, whereas paternal atopy mainly affects the latter. Maternally transmitted genes GSTP1 and FceRI-beta are associated with lung function and allergic sensitization, respectively. In IgE production and asthma development, the maternal influence on gene-environment interaction is greater than paternal influence. Maternal, paternal, and/or postnatal environmental modulation of allergic responses have been linked to epigenetic mechanisms, which may be good targets for early prevention of asthma.

Does genetic regulation of IgE begin in utero? Evidence from T(H)1/T(H)2 gene polymorphisms and cord blood total IgE

BACKGROUND

Elucidation of early life factors is critical to understand the development of allergic diseases, especially those manifesting in early life such as food allergies and atopic dermatitis. Cord blood IgE (CBIgE) is a recognized risk factor for the subsequent development of allergic diseases. In contrast with numerous genetic studies of total serum IgE in children and adults, limited genetic studies on CBIgE have been conducted.

OBJECTIVE

To test the associations between functional or tagging single nucleotide polymorphisms (SNPs) in genes involved in the T(H)1/T(H)2 pathway and CBIgE in a large US inner-city birth cohort.

METHODS

CBIgE, measured by Phadia ImmnunoCAP, was analyzed as a continuous and a binary variable. The association of each SNP with the 2 outcomes was tested using tobit and logistic regression models, respectively, with adjustment for pertinent covariates, ancestral proportion, and multiple testing. Ethnic heterogeneity and gene-gene interactions were also explored.

RESULTS

Three SNPs (rs1800925, rs2069743, and rs1295686) in the IL13 gene were significantly associated with CBIgE concentration (P ≤ 6 × 10(-4), FDR-corrected P < .05). These SNPs jointly influenced CBIgE in a dose-response manner (P for trend = 9 × 10(-8)). Significant associations also were observed for SNPs in the IL-13 receptor α1 (rs5956080) and signal transducer and activator of transcription 6 (rs11172106) genes. Ethnicity-specific genetic effects were observed for SNPs in the IL5 and GATA3 genes. Several gene-gene interactions (including IL13-IL4 receptor and IL13-signal transducer and activator of transcription 6 interactions) were detected in relation to CBIgE.

CONCLUSION

Our data demonstrated that multiple SNPs were individually and jointly associated with CBIgE, with evidence of gene-gene interactions and ethnic heterogeneity. These findings suggest that genetic regulation of IgE may begin in utero.

CTLA-4, position 49 A/G polymorphism associated with coronary artery lesions in Kawasaki disease

OBJECTIVE

Kawasaki disease (KD) is a systemic vasculitis of unknown etiology and primarily affects children less than 5 years of age. Cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) has been suggested as a candidate gene for conferring susceptibility to autoimmunity. This study examined the correlation of CTLA-4 gene polymorphisms in KD with and without coronary artery lesions (CAL).

MATERIALS AND METHODS

A total of 233 KD patients and 644 controls were subjected to determination of CTLA-4 polymorphisms at (-318) C/T and (+49) A/G positions by restriction fragment length polymorphism. Susceptibility, CAL, and intravenous immunoglobulin treatment response of KD were then analyzed with genetic variants.

RESULTS

Polymorphisms of CTLA-4 (+49 A/G) and (-318 C/T) were not significantly different between normal children and patients with KD. The CTLA-4 (+49) A allele (AA+AG genotype), however, was significantly associated with CAL formation, especially in female patients.

CONCLUSIONS

This study provides the first evidence supporting the association of CTLA-4 (+49) A/G polymorphism with the CAL formation of KD particularly in female patients.

CTLA4 and CD86 gene polymorphisms and susceptibility to chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) may be related to chronic inflammation and immune-mediated conditions, and its pathogenesis involves T-cell activation and proliferation. Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and costimulatory molecules (CD80/CD86) genes are important mediators of T-cell activation in the immune response. The aim of this study was to investigate whether +2379G/C (rs17281995) and +1057G/A (rs1129055) in CD86 and -318C/T (rs5742909) and +49A/G (rs231775) in CTLA-4 genes single nucleotide polymorphisms (SNPs) are associated with COPD in a Chinese population. The four polymorphisms were identified in 396 COPD patients and 400 controls using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The frequency of the T allele of the -318C/T in CTLA-4 and the A allele of the +1057G/A in CD86 polymorphisms showed significant association with COPD when compared with controls (T allele: p < 0.0001; A allele: p = 0.009). Comparison of genotype frequencies showed that -318CT, +1057GA, and +1057AA genotype was overrepresented in the COPD group, respectively (-318CT: 50.8% vs 28.5%, p < 0.0001; +1057GA: 58.6% vs 54.2%, p = 0.002; +1057AA: 30.1% vs 25.8%, p = 0.002). However, we failed to find any association between the four SNPs and COPD when cases were classified by smoking status or clinical stages (p > 0.05). The results indicate that the polymorphisms of CTLA-4 (-318C/T) and CD86 (+1057G/A) may be important genetic factor associated with risk or protection for COPD in Chinese population.

MicroRNA-21 expression in neonatal blood associated with antenatal immunoglobulin E production and development of allergic rhinitis

BACKGROUND

The prevalence of allergic diseases has increased in the past decades. It is unknown whether expression of certain microRNAs (miRNAs) in neonatal leucocytes is correlated to IgE production and/or allergic diseases.

OBJECTIVE

This study investigated the association of miRNA expression in neonatal leucocytes with cord blood IgE (CBIgE) elevation and development of allergic disease.

METHODS

We screened for the expression of a panel of 157 miRNAs in mononuclear leucocytes from human umbilical cord blood (CB) samples with elevated CBIgE and tracked the association of down-regulated miRNA expression to the miRNA-targeted gene expression and to children with allergic rhinitis (AR).

RESULTS

Among the initial screen of 10 CB samples with elevated CBIgE, expression of eight of the 157 miRNAs was low. Of these eight down-expressed miRNAs, three remained down-regulation in a validation with other 20 CB samples, and two of the three miRNAs, miR-21 and miR-126, were significantly lower in monocytes from AR children. Further analysis of mRNA expression of the miR-21-targeted genes identified that TGFBR2 expression on monocytes was significantly up-regulated in CB with elevated CBIgE, and in AR patients. Transfection of miR-21 precursor into monocytes from patients with AR increased miR-21 expression and decreased TGFBR2 expression.

CONCLUSION

This study demonstrated the first in the literature that lower miR-21 expression in CB and increased TGFBR2 expression is associated with antenatal IgE production and development of AR.

Gene-gene and gene-environment interactions on IgE production in prenatal stage

BACKGROUND

Prevalence of allergic diseases in children has increased worldwide over the past decades. Allergy sensitization may occur in fetal life. This study investigated whether gene-gene and gene-environment interactions affected cord blood IgE (CBIgE) levels.

METHODS

A total of 575 cord blood DNA samples were subjected to a multiplex microarray for 384 single nucleotide polymorphisms (SNPs) in 159 allergy candidate genes. Genetic association was initially assessed by univariate and multivariate analyses. Multifactor dimensionality reduction (MDR) was used to identify gene-gene and gene-environment interactions. Environmental factors for analysis included maternal atopy, paternal atopy, parental smoking, gender, and prematurity.

RESULTS

Twenty-one SNPs in 14 genes were associated with CBIgE elevation (>or =0.5 KU/l) in univariate analysis. Multivariate analysis identified eleven genes (IL13, IL17A, IL2RA, CCL17, CXCL1, PDGFRA, FGF1, HAVCR1, GNAQ, C11orf72, and ADAM33) which were significantly associated with CBIgE elevation. MDR analyses of gene-gene interactions identified IL13 interacted with IL17A and/or redox genes on CBIgE elevation with the prediction accuracy of 62.52%. Analyses of gene-environment interactions identified that maternal atopy combined with IL13, rs1800925 and CCL22, rs170359 SNPs had the highest prediction accuracy of 67.15%. All the high and low risk classifications on gene-gene and gene-environment interactions by MDR analyses could be validated by Chi-square test.

CONCLUSIONS

Gene-gene (e.g. immune and redox genes) and gene-environment (e.g. maternal atopy and FGF1or redox genes) interactions on IgE production begin in prenatal stage, suggesting that prevention of IgE-mediated diseases may be made possible by control of maternal atopy and redox responses in prenatal stage.

Genetics of food allergy

PURPOSE OF REVIEW

Food allergy, a growing clinical and public health problem in the United States and worldwide, is likely determined by multiple environmental and genetic factors. The purpose of this review is to summarize recent advances in food allergy genetic research.

RECENT FINDINGS

There is compelling evidence that genetic factors may play a role in food allergy. However, the specific genetic loci that may modulate individual risk of food allergy remain to be identified. To date, only a limited number of candidate gene association studies of food allergy have been reported. Polymorphism(s) in nine genes have been associated with the incidence of food allergy or food allergy severity in at least one study. But most of these findings remain to be replicated in independent populations. In contrast, there are considerable advances in genetics of other allergic diseases such as asthma and atopic dermatitis. Although asthma and atopic dermatitis often coexist with food allergy, the relevance of their candidate genes to food allergy remains to be evaluated.

SUMMARY

Genetics in food allergy is a promising research area but is still in its infancy. More studies are needed to dissect susceptible genes of food allergy. A genome-wide association approach may serve as a powerful tool to identify novel genes related to food allergy. Furthermore, the role of gene-environment interaction, gene-gene interaction, and epigenetics in food allergy remains largely unexplored. Given the complex nature of food allergy, future studies need to integrate environment, genomics, and epigenomics in order to better understand the multifaceted etiology and biological mechanisms of food allergy.

Combination of CTLA-4 and TGFbeta1 gene polymorphisms associated with dengue hemorrhagic fever and virus load in a dengue-2 outbreak

The pathogenesis of dengue hemorrhagic fever (DHF) has been considered to be massive immune activation of T cells. Abnormal expression of the immune regulatory molecules, CTLA-4 and TGFbeta1, leads to disturbances of regulatory T cell immune response. We investigate the contribution of CTLA-4 and TGFbeta1 in DHF by analyzing them for association with virus load in blood and polymorphisms of CTLA-4 +49A/G, and TGFbeta1 -509C/T in a DEN-2 outbreak. The increased frequency of the TGFbeta1 -509 CC genotype in patients with DHF was compared to those with dengue fever (OR=1.9, p=0.034). Moreover, the presence of the CTLA-4 +49 G allele and TGFbeta1 -509 CC genotype increased the susceptibility to risk of DHF (OR=2.1, p=0.028) and significantly higher virus load (p=0.013). This finding suggests that a combination of CTLA-4 and TGFbeta1 polymorphisms is associated with the susceptibility of DHF and higher virus load.

CTLA-4 single-nucleotide polymorphisms in a Caucasian population with schizophrenia

Associations between a single-nucleotide polymorphism (SNP) in exon 1 of the cytotoxic T-lymphocyte antigen-4 (CTLA4) gene and schizophrenia in a Korean population have been previously described. The current study investigated whether a similar link occurs in a Caucasian population with schizophrenia. One hundred and twenty-two age- and sex-matched pairs of people with DSM-III-R diagnosis of schizophrenia and healthy controls were included in this study. Three previously described SNPs (from the promoter, exon 1 and 3' UTR) of the CTLA4 gene were analysed. In the entire sample, we detected no allelic or genotypic association for any of the three SNPs. Given documented gender differences in incidence of schizophrenia, we conducted separate analyses of male and female participants. In males, both the promoter region SNP (-318C/T) and the 3' UTR SNP demonstrated nominally significant association with schizophrenia. The 3' UTR SNP remained significant following correction for multiple testing (permuted P=0.046). In addition, all possible haplogenotypes showed significant association with disease in males with two--both containing the 3' UTR SNP--remaining significant following correction for the genotypic tests of all SNPs and haplogenotypes in males. These results suggest a role for the 3' UTR SNP and/or variants in high linkage disequilibrium with this SNP in the pathogenesis of schizophrenia.

Tumor necrosis factor-alpha is a common genetic risk factor for asthma, juvenile rheumatoid arthritis, and systemic lupus erythematosus in a Mexican pediatric population

There is a great deal of evidence that points to the association of the tumor necrosis factor-alpha (TNF-alpha) gene as a common genetic factor in the pathogenesis of diseases that are caused by inflammatory and/or autoimmune etiologies. Two single nucleotide polymorphisms (SNPs) identified in the TNF-alpha promoter region have been associated with disease susceptibility and severity. We investigated whether -308G/A and -238G/A TNF-alpha polymorphisms were associated with asthma, systemic lupus erythematosus (SLE), and juvenile rheumatoid arthritis (JRA) in a pediatric Mexican population. In a case-control study of 725 patients (asthma: 226, JRA: 171, and SLE: 328) and 400 control subjects, the participants were analyzed using the allelic discrimination technique. The genotype distribution of both TNF-alpha polymorphisms was in Hardy-Weinberg equilibrium in each group. However, there were significant differences in the allele frequency of TNF-alpha-308A between the patients and the healthy controls. This allele was detected in 2.9% of the controls, 6.0% of asthmatic and JRA patients (p = 0.002 and p = 0.0086), and 6.7% of SLE patients (p = 0.00049); statistical significance was maintained after ancestry stratification (asthma: p = 0.0143, JRA: p = 0.0083, and SLE: p = 0.0026). Stratification by gender showed that the risk for the -308A allele in asthma and JRA was greater in females (OR = 4.16, p = 0.0008 and OR = 4.4, p = 0.0002, respectively). The TNF-alpha -238A allele showed an association only with JRA in males (OR = 2.89, p = 0.004). These results support the concept that the TNF-alpha gene is a genetic risk factor for asthma, SLE, and JRA in the pediatric Mexican population.

Cord serum immunoglobulin E as a risk factor for allergic symptoms and sensitization in children and young adults

Early markers of atopic predisposition are needed for targeting allergy preventive measures to high-risk infants. An elevated cord serum immunoglobulin E (CS-IgE) level is considered a risk factor for subsequent allergy in childhood. However, the previous studies have not assessed the predictive value of CS-IgE in a follow-up extended to adulthood. We aimed at clarifying whether CS-IgE is useful in predicting subsequent atopic manifestations up to age 20 yr. A cohort of 200 unselected, full-term newborns were prospectively followed up from birth to age 20 yr. The CS-IgE level was successfully measured in 190 subjects at birth. The subjects were re-examined at ages of 5, 11 and 20 yr with assessment of the occurrence of allergic symptoms during the preceding year, skin prick testing and measurement of serum total IgE. An elevated CS-IgE level was associated with allergic symptoms and skin prick test positivity at age 5 yr (p = 0.03 and 0.01), with allergic rhinoconjunctivitis at age 20 yr (p = 0.04) and with an elevated serum total IgE at ages of 11 and 20 yr (p = 0.02 and 0.01). The sensitivity of CS-IgE, i.e. the probability of an elevated CS-IgE in an infant who subsequently develops atopy, in predicting skin prick test-verified atopy at ages of 5 and 20 yr was 50% and 26%, respectively. The combination of elevated CS-IgE and positive family history of allergy was strongly associated with subsequent atopic manifestations. Nevertheless, it showed a reduced sensitivity as compared to CS-IgE or family history of allergy. We conclude that an elevated CS-IgE level predicts subsequent atopy up to age 20 yr.

Gender-specific effects of cytokine gene polymorphisms on childhood vaccine responses

Cytokine gene polymorphisms affect vaccine responses and gender-specific effects are known for many phenotypes. Therefore, this study investigated gender-specific effects of cytokine gene polymorphisms on vaccine responses. In 263 2-year-old subjects selected for parental history of atopy, boys with IL-4 C-589T and IL-4Ralpha I50V genotypes associated with atopy had increased Diptheria Toxoid (DiphTox) and Tetanus Toxoid (TetTox) responses compared with the remaining alleles (IL-4 C-589T: DipTox p=0.01, TetTox p=0.04; IL-4Ralpha.I50V: DipTox p=0.04, TetTox p=0.08). Contrastingly, girls with IL-10 -592C genotypes associated with atopy had lower levels of DiphTox (p=0.03) and TetTox (p=0.02) responses compared with the remaining allele. Additionally, interaction effects were found for IL-4 C-589T (p=0.01) and IL-4Ralpha I50V (p=0.04) polymorphisms. In conclusion, these findings support the interaction of primary genetic and modifying factors on vaccine responses and the importance of atopic genetics to these responses.

Infant frequent wheezing correlated to Clara cell protein 10 (CC10) polymorphism and concentration, but not allergy sensitization, in a perinatal cohort study

BACKGROUND

Wheezing episodes are common in young infants. However, the molecular mechanism of wheezing is unclear, and very few therapeutic regimens are effective.

OBJECTIVE

This study investigated the genetic and environmental factors predisposing to infant wheezing in a birth cohort study.

METHODS

A cohort of 1211 pregnant women was recruited for this study. Infant wheezing episodes during the first 18 months of life were correlated to parental atopic history, parental smoking, prematurity, CB IgE levels, and the sequence variant (G+38A) of the Clara cell protein 10 (CC10) gene encoding a secretary anti-inflammatory CC10 protein.

RESULTS

Nine hundred eighty-three infants completed umbilical cord blood collection, and 813 infants completed the 18-month postnatal follow-up. Twenty-two percent of the infants experienced at least 1 wheezing episode, and 6.6% of the infants experienced frequent wheezing (> or =3 episodes). Multivariate logistic regression showed that male sex and the CC10 G+38A polymorphism, but not prematurity, CB IgE level, passive smoking, or parental atopy, were predictors of frequent wheezing. Further studies found that infant frequent wheezing was significantly associated with the CC10 +38AA genotype and lower plasma CC10 levels at 18 months of age (P = .046), and infants with acute wheezing episodes had significantly lower CC10 levels than those without (P = .023). No association of wheezing episodes with allergic sensitization was observed in this cohort population.

CONCLUSION

Infant frequent wheezing is associated with the CC10 G+38A polymorphism and lower CC10 levels but not infant atopy.

CLINICAL IMPLICATIONS

Lower CC10 expression, but not allergy sensitization, is involved in the pathogenesis of infant frequent wheezing.

IL13 gene polymorphism association with cord serum immunoglobulin E

Interleukin-13 (IL-13) has a pivotal role in the pathway of immunoglobulin E (IgE). Cord serum IgE has been suggested to be associated with allergy later in life, yet less affected by environmental exposures. We investigated the association of the interleukin-13 gene (IL13) polymorphisms on cord serum IgE. In the Isle of Wight birth cohort (UK, 1989-1990), cord serum IgE was measured using the ULTRA EIA kit and was dichotomized at 0.5 kU/l (n = 1358). Five single nucleotide polymorphisms (SNPs: rs1800925 in promoter, rs2066960 in intron 1, rs1295686 in intron 3, rs20541 in exon 4 and rs1295685 in exon 4) in IL13 were genotyped by pyrosequencing method. Linkage analysis using Haploview software revealed that rs1295686, rs20541 and rs1295685 were in strong linkage disequilibrium. Logistic regression and Armitage-Cochran test were used and gene association analysis included 798 children. Confounders were maternal age; maternal smoking, household dog, and household cat during pregnancy; season of birth; sex; position of child in family; and birth weight. SNP rs1295685 was associated with raised cord serum IgE (p = 0.031). This is the first report that shows an association between IL13 polymorphism and cord serum IgE.

Interaction of maternal atopy, CTLA-4 gene polymorphism and gender on antenatal immunoglobulin E production

BACKGROUND

Genetic heritability and maternal atopy have been correlated to antenatal IgE production, but very few studies have studied gene-maternal atopy interaction on antenatal IgE production. This study investigated the interaction of CTLA-4 polymorphism with prenatal factors on the elevation of cord blood IgE (CBIgE).

METHODS

Pregnant women were antenatally recruited for collection of prenatal environmental factors by a questionnaire. Umbilical cord blood samples were collected for CBIgE detection by fluorescence-linked enzyme assay and CTLA-4 polymorphism measurement by restriction fragment length polymorphism.

RESULTS

A total of 1104 pregnant women initially participated in this cohort study, and 898 of them completed cord blood collection. 21.4% of the newborns had elevation of CBIgE (>or=0.5 kU/L). The CTLA-4+49A allele (P=0.021), maternal atopy (P<0.001) and gender (P=0.034), but not the CTLA-4+49G allele, -318C allele, -318T allele, parental smoking or paternal atopy, were significantly correlated with the CBIgE elevation in multivariate analysis. A dichotomous analysis of gene-maternal atopy interactions identified maternal atopy and CTLA-4+49A allele had an additive effect on the CBIgE elevation, especially prominent in male newborns; and in the absence of maternal atopy, CTLA-4+49GG genotype had a protective effect on CBIgE elevation in female newborns.

CONCLUSIONS

Maternal but not paternal atopy has significant impacts on CBIgE elevation depending on gender and CTLA-4+49A/G polymorphism of newborns. Control of maternal atopy and modulation of CTLA-4 expression in the prenatal stage may be a target for the early prevention of perinatal allergy sensitization.

Phenotype definition, age, and gender in the genetics of asthma and atopy

When studying genetics of complex diseases it is important to have a clearly described and objective phenotype. When drawing conclusions in association studies, age and gender of the population should be considered. Until we know what causes phenotypic differences between males and females and between children and adults, we should try to study longitudinal cohorts with phenotype assessment at different time points and stratify our analyses for gender. To acquire sufficient power for these types of analyses, international collaboration may be the only way to elucidate the intricate, gene-environmental interactions in atopy and asthma in an age- and gender-dependent manor.