Polymorphism of the immune-braking gene CTLA-4 (+49) involved in gender discrepancy of serum total IgE levels and allergic diseases

Reliability of Total Serum IgE Levels to Define Type 2 High and Low Asthma Phenotypes

Background: High total IgE levels are weak predictors of T2High and have been reported in nonallergic asthma. Therefore, the role of total serum IgE (IgE) in the T2High phenotype is still debated. Objective: This study investigated the reliability of stratifying asthmatics into IgEHigh and IgELow within the T2High and T2Low phenotypes. Methods: This cross-sectional single-center study investigated the association of clinical, functional, and bio-humoral parameters in a large asthmatic population stratified by IgE ≥ 100 kU/L, allergen sensitization, B-EOS ≥ 300/µL, and FENO ≥ 30 ppb. Results: Combining T2 biomarkers and IgE identifies (1) T2Low-IgELow (15.5%); (2) T2Low-IgEHigh (5.1%); (3) T2High-IgELow (33.6%); and T2High-IgEHigh (45.7%). T2Low-IgELow patients have more frequent cardiovascular and metabolic comorbidities, a higher prevalence of emphysema, and higher LAMA use than the two T2High subgroups. Higher exacerbation rates, rhinitis, and anxiety/depression syndrome characterize the T2Low-IgEHigh phenotype vs. the T2Low-IgELow phenotype. Within the T2High, low IgE was associated with female sex, obesity, and anxiety/depression. Conclusions: High IgE in T2Low patients is associated with a peculiar clinical phenotype, similar to T2High in terms of disease severity and nasal comorbidities, while retaining the T2Low features. IgE may represent an additional biomarker for clustering asthma in both T2High and T2Low phenotypes rather than a predictor of T2High asthma "per se".

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.

Genome-wide analysis highlights contribution of immune system pathways to the genetic architecture of asthma

Asthma is a chronic and genetically complex respiratory disease that affects over 300 million people worldwide. Here, we report a genome-wide analysis for asthma using data from the UK Biobank and the Trans-National Asthma Genetic Consortium. We identify 66 previously unknown asthma loci and demonstrate that the susceptibility alleles in these regions are, either individually or as a function of cumulative genetic burden, associated with risk to a greater extent in men than women. Bioinformatics analyses prioritize candidate causal genes at 52 loci, including CD52, and demonstrate that asthma-associated variants are enriched in regions of open chromatin in immune cells. Lastly, we show that a murine anti-CD52 antibody mimics the immune cell-depleting effects of a clinically used human anti-CD52 antibody and reduces allergen-induced airway hyperreactivity in mice. These results further elucidate the genetic architecture of asthma and provide important insight into the immunological and sex-specific relevance of asthma-associated risk variants.

Asthma is a common disease of the airways for which numerous genetic loci have been identified. Here, Han et al. carry out a genome-wide analysis for asthma to identify additional loci, report sex-stratified and genetic risk score analyses, and functionally follow-up one locus using a murine model of airway hyperreactivity.

Childhood atopic dermatitis: current developments, treatment approaches, and future expectations

Atopic dermatitis (AD) is the most common chronic inflammatory skin disorder of childhood. Underlying factors that contribute to AD are impaired epithelial barrier, alterations in the lipid composition of the skin, immunological imbalance including increased Th2/Th1 ratio, proinflammatory cytokines, decreased T regulatory cells, genetic mutations, and epigenetic alterations. Atopic dermatitis is a multifactorial disease with a particularly complicated pathophysiology. Discoveries to date may be considered the tip of the iceberg, and the increasing number of studies in this field indicate that there are many points to be elucidated in AD pathophysiology. In this review, we aimed to illustrate the current understanding of the underlying pathogenic mechanisms in AD, to evaluate available treatment options with a focus on recently discovered therapeutic agents, and to determine the personal, familial, and economic burdens of the disease, which are frequently neglected issues in AD. Currently available therapies only provide transient solutions and cannot fully cure the disease. However, advances in the understanding of the pathogenic mechanisms of the disease have led to the production of new treatment options, while ongoing drug trials also have had promising results.

Chinese Society of Allergy Guidelines for Diagnosis and Treatment of Allergic Rhinitis

Allergic rhinitis (AR) is a global health problem that causes major illnesses and disabilities worldwide. Epidemiologic studies have demonstrated that the prevalence of AR has increased progressively over the last few decades in more developed countries and currently affects up to 40% of the population worldwide. Likewise, a rising trend of AR has also been observed over the last 2-3 decades in developing countries including China, with the prevalence of AR varying widely in these countries. A survey of self-reported AR over a 6-year period in the general Chinese adult population reported that the standardized prevalence of adult AR increased from 11.1% in 2005 to 17.6% in 2011. An increasing number of Journal Articles and imporclinical trials on the epidemiology, pathophysiologic mechanisms, diagnosis, management and comorbidities of AR in Chinese subjects have been published in international peer-reviewed journals over the past 2 decades, and substantially added to our understanding of this disease as a global problem. Although guidelines for the diagnosis and treatment of AR in Chinese subjects have also been published, they have not been translated into English and therefore not generally accessible for reference to non-Chinese speaking international medical communities. Moreover, methods for the diagnosis and treatment of AR in China have not been standardized entirely and some patients are still treated according to regional preferences. Thus, the present guidelines have been developed by the Chinese Society of Allergy to be accessible to both national and international medical communities involved in the management of AR patients. These guidelines have been prepared in line with existing international guidelines to provide evidence-based recommendations for the diagnosis and management of AR in China.

The role of regulatory T cells and genes involved in their differentiation in pathogenesis of selected inflammatory and neoplastic skin diseases. Part III: Polymorphisms of genes involved in Tregs' activation and function

Regulatory T cells (Tregs) represent a cell type that promotes immune tolerance to autologous components and maintains immune system homeostasis. The abnormal function of Tregs is relevant to the pathogenesis of several skin diseases like psoriasis, atopic dermatitis, systemic lupus erythematosus, cutaneous T-cell lymphomas, and skin cancer and is also important in rheumatoid arthritis, diabetes and other autoimmune diseases. In this review, we will summarize the role of mutations and/or polymorphisms of genes involved in Tregs development, and functions in the pathogenesis of selected skin diseases.

Polymorphism of IL10, IL4, CTLA4, and DAO Genes in Cross-Reactive Nonsteroidal Anti-inflammatory Drug Hypersensitivity

Our aim was to evaluate genetic polymorphism of molecules involved in immunoregulatory/allergic processes in patients who presented with cutaneous hypersensitivity caused by chemically unrelated nonsteroidal anti-inflammatory drugs. Polymorphisms at IL10 (-1082 G>A), IL4 (-589 C>T), CTLA4 (+49A>G), and DAO (+8956 C>G) genes were studied in 55 cases and 97 controls by the polymerase chain reaction-restriction fragment length polymorphism technique. With regard to the polymorphism at IL10 -1082, higher frequencies of the AG genotype (57% vs 39%) and G allele carriers (70% vs 48%) were found among the patients, indicating a risk effect (odds ratio [OR] = 2.56 and P = .01 for AG genotype and OR = 2.52; P = .01 for AG/GG). For the CTLA4 +49 A/G single-nucleotide polymorphism (SNP), AG genotype (31.0%) (P = .02) and G carrier (54.0%) (P = .05) frequencies were found to be significantly lower in the patient group compared with the control group (51.0% and 69.0%, respectively). The SNP DAO +8956 C>G was associated with a strong protective effect, with OR values of 0.83 for CG and 0.11 for GG genotype (P = .04 for the codominant model), suggesting an allele dose effect. The combination of IL10 and DAO SNPs in a multivariate model did not alter the OR values, suggesting independent effects for both SNPs. The results are striking. In conclusion, these results suggest that polymorphisms in regulatory targets of the immune response and in DAO gene could modulate an individual's susceptibility to nonsteroidal anti-inflammatory drug hypersensitivity reactions. Further studies will be necessary to complement our results.

Genomic architecture of asthma differs by sex

Asthma comprised of highly heterogeneous subphenotypes resulting from complex interplay between genetic and environmental stimuli. While much focus has been placed on extrinsic environmental stimuli, intrinsic environment such as sex can interact with genes to influence asthma risk. However, few studies have examined sex-specific genetic effects. The overall objective of this study was to evaluate if sex-based differences exist in genomic associations with asthma. We tested 411 asthmatics and 297 controls for presence of interactions and sex-stratified effects in 51 genes using both SNP and gene expression data. Logistic regression was used to test for association. Over half (55%) of the genetic variants identified in sex-specific analyses were not identified in the sex-combined analysis. Further, sex-stratified genetic analyses identified associations with significantly higher median effect sizes than sex-combined analysis for girls (p-value=6.5E-15) and for boys (p-value=1.0E-7). When gene expression data were analyzed to identify genes that were differentially expressed in asthma versus non-asthma, nearly one third (31%) of the probes identified in the sex-specific analyses were not identified in the sex-combined analysis. Both genetic and gene expression data suggest that the biologic underpinnings for asthma may differ by sex. Failure to recognize sex interactions in asthma greatly decreases the ability to detect significant genomic variation and may result in significant misrepresentation of genes and pathways important in asthma in different environments.

Association between promoter polymorphisms of interleukin-4 gene and allergic rhinitis risk: a meta-analysis

The relationship of interleukin-4 (IL-4) C-33T and C-590T (C-589T) gene polymorphisms with allergic rhinitis was analyzed. Data about the case control studies of IL-4 gene promoter polymorphisms [C-33T and C-590T (C-589T)] and their association with allergic diseases and correlation between serum IL-4 levels and allergic rhinitis were retrieved. The Stata 12.0 statistical software was applied to analyze the correlation between IL-4 gene polymorphisms and allergic rhinitis. The meta-analysis result of TT/CC genotype of -590 (-589) polymorphism showed a significant association with allergic diseases [OR=1.93, 95% CI (1.61-2.31), P=0.00]. Meta-analysis of the TT+TC versus CC genotype of IL-4 C-33/T polymorphism revealed significant associations with allergic diseases [OR=3.23, 95% CI (1.13-9.25), P=0.03]. Meanwhile, there was a significant correlation between serum IL-4 levels and allergic rhinitis [OR=2.52, 95% CI=(1.80-3.23), P=0.00]. IL-4 gene -590 TT genotype may increase the risk of allergic rhinitis and the T allele mutation of -33 might be correlated with allergic rhinitis.

Association between genes encoding components of the IL-4/IL-4 receptor pathway and dermatitis in children

OBJECTIVE

To determine whether IL-4, IL-4Rα and STAT6 polymorphisms are associated with susceptibility to dermatitis in Egyptian children.

METHODS

We genotyped three groups of children, consisting of 106 atopic dermatitis (AD) children, 95 non-AD children, and 100 of healthy controls, for IL-4 (-590 C/T), (-33 C/T), IL-4Rα (I50V), (Q576R) and STAT6 (2964 G/A), (2892 C/T) gene polymorphisms using PCR-RFLP assay. Total serum IgE and serum IL-4 levels were detected by ELISA.

RESULTS

There was a non-significant association of IL-4 -590 C/T, -33 C/T polymorphisms in the children with non-AD or those with AD when compared with the controls. We identified a significant association between IL-4Rα I50V, Q576R polymorphisms and dermatitis susceptibility in AD (p=0.002, <0.001 respectively), whereas no such association was observed in non-AD group (p=0.52, 0.99 respectively). A significant association between STAT6 polymorphisms and both types of dermatitis was found. Patients who were carriers of IL4 -590C, IL-4Rα I50V G, STAT6 2964 A and STAT6 2892 T had an increased risk of AD [OR and 95% CI: 3.2 (2.5-4.2), p=0.005]. Furthermore, there was no relation between each polymorphism and serum IL-4 level (p>0.05 for each) while homozygosity for the risk alleles of IL-4, IL-4Rα and STAT6 SNPs were significantly associated with increased total IgE levels in all subjects.

CONCLUSION

In Egyptian children, the IL-4Rα and the STAT6 polymorphism may play a role in susceptibility to AD. In addition, gene-gene interaction between the IL-4, the IL-4Rα and the STAT6 significantly increases an individual's susceptibility to AD.

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).

Relation between objective measures of atopy and myocardial infarction in the United States

BACKGROUND

Although rodent studies indicate that atherosclerosis is a T(H)1-mediated disease and that atopic T(H)2 immunity is atheroprotective, findings in humans are conflicting. Total IgE (tIgE) is associated with atherosclerotic disease but has limited specificity for atopy.

OBJECTIVE

Our aim was to determine the relation between atopy, as indicated by a broad panel of serum allergen-specific IgE (sIgE), and past myocardial infarction (MI) in a sample representative of the US population.

METHODS

Data were analyzed from 4002 participants aged ≥ 20 years from the 2005-2006 National Health and Nutrition Examination Survey.

RESULTS

Subjects reporting a history of MI had lower summed sIgE (5.51 vs 7.71 kU/L; P < .001) and were less likely to have ≥ 1 positive sIgE test (29.9% vs 44.6%; P = .02) or current hay fever (3.3% vs 7.6%; P = .002). After adjustment for age, sex, race/ethnicity, diabetes mellitus, hypertension, family history of MI, smoking, total/high-density lipoprotein cholesterol, body mass index, and C-reactive protein, the odds ratio (OR) for MI was 0.91 (95% CI, 0.85-0.97) per positive sIgE; 0.70 (95% CI, 0.57-0.85) per 2-fold increase in sum[sIgE]; and 0.82 (95% CI, 0.69-0.98) per 10% increase in the ratio of sum[sIgE] to tIgE. Analysis with 7 data-driven, prespecified allergen clusters found that house dust mite is the only allergen cluster for which sIgE is associated with reduced odds for MI (fully adjusted OR, 0.36; 95% CI, 0.20-0.64).

CONCLUSION

Serum sIgE is inversely related to MI in the US population in a manner independent of multiple coronary risk factors.

Cytotoxic T-lymphocyte associated antigen 4 polymorphisms and asthma risk: a meta-analysis

Background

A number of studies assessed the association of cytotoxic T-lymphocyte associated antigen 4 (CTLA-4) gene polymorphisms with asthma in different populations. However, the results were contradictory. We performed a meta-analysis to examine the association between CTLA-4 polymorphisms and asthma susceptibility.

Methods

Pubmed, EMBASE, HuGE Navigator, and Wanfang Database were searched. Data were extracted independently by two reviewers. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of associations.

Results

Seventeen studies involving 6378 cases and 8674 controls were included. Significant association between +49 A/G polymorphism and asthma was observed for AA vs. AG+GG (OR = 1.18, 95% CI 1.01–1.37, P = 0.04). There were no significant associations between −318 C/T, −1147 C/T, CT60 A/G, −1722 C/T, or rs926169 polymorphisms and asthma risk.

Conclusions

This meta-analysis suggested that the +49 A/G polymorphism in CTLA-4 was a risk factor for asthma.

A meta-analysis of Th2 pathway genetic variants and risk for allergic rhinitis

There is a significant genetic contribution to allergic rhinitis (AR). Genetic association studies for AR have been performed, but varying results make it challenging to decipher the overall potential effect of specific variants. The Th2 pathway plays an important role in the immunological development of AR. We performed meta-analyses of genetic association studies of variants in Th2 pathway genes and AR. PubMed and Phenopedia were searched by double extraction for original studies on Th2 pathway-related genetic polymorphisms and their associations with AR. A meta-analysis was conducted on each genetic polymorphism with data meeting our predetermined selection criteria. Analyses were performed using both fixed and random effects models, with stratification by age group, ethnicity, and AR definition where appropriate. Heterogeneity and publication bias were assessed. Six independent studies analyzing three candidate polymorphisms and involving a total of 1596 cases and 2892 controls met our inclusion criteria. Overall, the A allele of IL13 single nucleotide polymorphism (SNP) rs20541 was associated with increased odds of AR (estimated OR=1.2; 95% CI 1.1-1.3, p-value 0.004 in fixed effects model, 95% CI 1.0-1.5, p-value 0.056 in random effects model). The A allele of rs20541 was associated with increased odds of AR in mixed age groups using both fixed effects and random effects modeling. IL13 SNP rs1800925 and IL4R SNP 1801275 did not demonstrate overall associations with AR. We conclude that there is evidence for an overall association between IL13 SNP rs20541 and increased risk of AR, especially in mixed-age populations.

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.

Association between CTLA-4 gene promoter (49 A/G) in exon 1 polymorphisms and inflammatory bowel disease in the Tunisian population

BACKGROUND/AIM

To investigate the possible association between the polymorphism of the CTLA-4 exon 1 +49 A/G and susceptibility to Crohn's disease (CD) and ulcerative colitis (UC) in the Tunisian population.

METHODS

The +49 A/G dimorphism was analyzed in 119 patients with CD, 65 patients with UC, and 100 controls by the polymerase chain reaction-restriction fragment length polymorphism method.

RESULTS

Significantly higher frequencies of the CTLA-4 +49A allele and A/A homozygous individuals were observed in patients with CD when compared with controls (pc = 0.0023 and pc = 0.0003, respectively). Analysis of CTLA-4 A/G polymorphism with respect to sex in CD showed a significant difference in A/A genotypes between female patients and controls (pc = 0.0001 and pc = 0.038, respectively). There were no differences in the subgroups of patients with CD.

CONCLUSIONS

Forty-nine A alleles and AA genotype are associated with CD susceptibility in Tunisians. Other genes involved in the T-cell regulation remain strong candidates for IBD susceptibility and require further investigation.

Genetic susceptibility to atopic dermatitis

Atopic dermatitis (AD) is a chronic inflammatory skin disorder with an increasing prevalence in industrialized countries. AD belongs to the group of allergic disorders that includes food allergy, allergic rhinitis, and asthma. A multifactorial background for AD has been suggested, with genetic as well as environmental factors influencing disease development. Recent breakthroughs in genetic methodology have greatly augmented our understanding of the contribution of genetics to susceptibility to AD. A candidate gene association study is a general approach to identify susceptibility genes. Fifty three candidate gene studies (50 genes) have identified 19 genes associated with AD risk in at least one study. Significant associations between single nucleotide polymorphisms (SNPs) in chemokines (chymase 1-1903A > G), cytokines (interleukin13 Arg144Gln), cytokine receptors (interleukin 4 receptor 1727G > A) and SPINK 1258G > A have been replicated in more than one studies. These SNPs may be promising for identifying at-risk individuals. SNPs, even those not strongly associated with AD, should be considered potentially important because AD is a common disease. Even a small increase in risk can translate to a large number of AD cases. Consortia and international collaborative studies, which may maximize study efficacy and overcome the limitations of individual studies, are needed to help further illuminate the complex landscape of AD risk and genetic variations.

Distribution of the CTLA-4 single nucleotide polymorphisms CT60G>A and +49A>G in psoriasis vulgaris patients and control individuals from a Polish Caucasian population

Psoriasis vulgaris is a multifactorial disease with an autoimmune component, and T lymphocytes seem to be involved in its aetiology. CTLA-4 molecule is an important down-regulator of T-lymphocyte activation, and several polymorphisms of the CTLA-4 gene were found to be associated with some autoimmune diseases. We examined whether single nucleotide polymorphisms (SNPs) in the CTLA-4 gene, CT60A>G and +49A>G, are associated with psoriasis vulgaris. Alleles of these two SNPs were determined by the polymerase chain reaction-restriction fragment length polymorphism method. Both the CT60G>A and the +49A>G alleles and genotypes were distributed similarly in patients and controls. Although the two SNPs studied here in Poles were in linkage disequilibrium, all four possible two-locus haplotypes were found, one of them rare; of the remaining three, the haplotype +49G, CT60G was significantly (P = 0.019, OR = 0.58, 95%CI = 0.37-0.91) less frequent in the patient group with disease onset between the ages of 21 and 40 years than in controls and the other patient groups, whereas the frequencies of the other haplotypes were similar in patients and controls. To the authors' knowledge, this is the first study on CTLA-4 CT60 allele frequencies in psoriasis.

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.

Cytotoxic T lymphocyte-associated antigen-4 gene polymorphisms confer susceptibility to atopic asthma in Korean children

Cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) is a negative regulator of T lymphocyte activation. The gene encoding CTLA-4 is a candidate gene for conferring susceptibility to allergic disease. The purpose of this study was to evaluate the potential effects of CTLA-4 gene polymorphisms in Korean children on asthma. We genotyped 272 children with atopic asthma, 54 children with nonatopic asthma (NAA), and 254 control children for allelic determinants at two polymorphic sites in the region at positions promoter - 318 C > T and exon 1 + 49 G > A using restriction fragment length polymorphism methods. As a result, allele and genotype frequencies of the CTLA-4 exon 1 + 49 G > A polymorphism were different to some extent between the atopic asthma children and the controls with P<0.05, which did not reach statistical significance after the correction of multiple comparisons. In addition, CTLA-4 + 49 G > A polymorphism was significantly associated with elevated serum IgE levels (P=0.01). Of the four haplotype, haplotype 1 (C-G) was only associated with atopic asthma susceptibility after the correction of multiple comparisons (P=0.01, OR=0.702, 95% CI= 0.541-0.911). Polymorphisms in the CTLA-4 gene likely confer susceptibility to atopic asthma in Korean children.

Immunology of anaphylaxis: lessons from murine models

The use of animal models is increasing, and mice are suitable animals to use in exploring systemic anaphylaxis based on the similarity between human and mouse immune systems. Two anaphylaxis pathways have been characterized in mice, which may help in understanding some of the discrepancies found in humans. In addition, cytokine studies are raising new concepts that may put together some of the puzzling mechanisms described in this disease. Finally, the study of the mechanisms that parasitic infections use to evade the human immune system and the scene in which a parasite induces clinical anaphylaxis are opening new insights in the immunology pathways and new strategies to fight against this exclusive disease.

Are there reasons why adult asthma is more common in females?

Many epidemiological studies suggest that women are at increased risk of developing adult-onset asthma and also suffer from more severe disease than men. These gender differences appear to be the product of biological sex differences as well as sociocultural and environmental differences. The biological sex differences include genetic, pulmonary, and immunological factors. There is compelling evidence that sex hormones are major determinants of at least these biological sex differences. This paper explores the current literature regarding effects of sex hormones on immune function, resident lung cells, and regulation of local processes in the lung to shed light on underlying mechanisms of gender differences in asthma. More research is needed to understand these mechanisms in order to improve treatment of women with asthma.

Linkage analysis of a cluster-based quantitative phenotype constructed from pulmonary function test data in 27 multigenerational families with multiple asthmatic members

OBJECTIVE

To identify genes involved in phenotypes that increase one's risk for developing asthma, a complex disease that is likely genetically heterogeneous. Unlike other approaches to locus discovery in the presence of heterogeneity, this method seeks loci that segregate in all or most ascertained families while recognizing that other genes and environmental factors that modify the action of the common gene may vary across families.

METHODS

The method is based on seeking groups of families that differ, between groups, in the way affected individuals express the genotype. Then we use the distance of each individual to the cluster center for his family to define a quantitative trait. This quantitative trait is then subjected to a genome scan using variance components methods.

RESULTS

The method is applied to a data set of 27 multigenerational families with asthma, and a novel locus at 2q33 (at 210 cM) is identified.

CONCLUSIONS

The proposed method has the potential to identify loci near genes that increase risk for asthma related phenotypes. The method could be used for other complex disorders that exhibit locus heterogeneity.

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.

Distribution of CTLA-4 polymorphisms in allergic asthma

BACKGROUND

The CTLA-4 molecule is an important negative regulator of T cell activation. It is encoded on chromosome 2q33 and found to be associated with several allergic phenotypes including asthma. However, the association of CTLA-4 gene polymorphisms with allergic asthma is still controversial and therefore was the subject of this study.

METHODS

By PCR-RFLP, the distribution of three single nucleotide polymorphisms (SNPs), -1147 C/T, -318 C/T, and +49 A/G, was examined in 219 Polish Caucasoid patients diagnosed with allergic asthma and in 102 ethnically matched healthy control individuals. (AT)(n) microsatellite polymorphism was also tested in the same individuals.

RESULTS

No statistically significant differences in SNPs or microsatellite allele, genotype or haplotype frequencies between patients and controls were found.

CONCLUSION

CTLA-4 polymorphisms do not seem to be a risk factor for allergic asthma in Poles.

Perinatal risk factors for sensitization, atopic dermatitis and wheezing during the first year of life (PIPO study)

OBJECTIVE

To evaluate the influence of perinatal environmental factors on early sensitization, atopic dermatitis and wheezing during the first year.

METHODS

Information on pregnancy-related factors, parental atopic history, environmental factors and the clinical course of the infant until age one was gathered by questionnaires, as part of a prospective birth cohort study (Prospective study on the Influence of Perinatal factors on the Occurrence of asthma and allergies [PIPO-study]). Quantification of total and specific IgE was performed in 810 children and their parents.

RESULTS

Early sensitization was found in 107/810 (13%) of the infants. Multiple regression analysis showed that specific IgE in fathers was a risk factor for early sensitization in their daughters (adjusted odds ratios (OR(adj)) 2.21 (95% confidence interval (CI) 1.10-4.49); P=0.03), whereas in boys, day care attendance was shown to be protective for early sensitization (OR(adj) 0.38 (95% CI 0.20-0.71); P=0.001). Atopic dermatitis occurred in 195/792 infants (25%). Specific IgE in the mother (OR(adj) 1.52 (95% CI 1.06-2.19); P=0.02) and in the infant (OR(adj) 4.20 (95% CI 2.63-6.68); P<0.001) were both risk factors for the occurence of atopic dermatitis, whereas postnatal exposure to cats was negatively associated with atopic dermatitis (OR(adj) 0.68 (0.47-0.97); P=0.03). Postnatal exposure to cigarette smoke (OR(adj) 3.31 (95% CI 1.79-6.09); P<0.001) and day care attendance (OR(adj) 1.96 (95% CI 1.18-3.23); P=0.009) were significantly associated with early wheezing, which occurred in 25% (197/795) of the infants.

CONCLUSION

The effect of paternal sensitization and day care attendance on sensitization is gender dependent. Maternal sensitization predisposes for atopic dermatitis, whereas postnatal exposure to cats had a protective effect.

The course of eczema in children aged 5-7 years and its relation to atopy: differences between boys and girls

BACKGROUND

The role of atopy in the pathophysiology of eczema is still under debate. The concept and analyses of the nonatopic and atopic subtypes of eczema have gained increasing interest in recent studies. The course of these subtypes and differences between boys and girls have not been investigated so far.

OBJECTIVES

To examine the course of nonatopic and atopic eczema in preschool children from Germany with regard to sex.

METHODS

Repeated cross-sectional studies were performed in 5-7-year-old preschool children from Germany between 1994 and 2000. Individuals with eczema were identified by a dermatological examination. In addition to a questionnaire, skin prick tests and analyses of serum IgE antibodies against seven and five environmental allergens, respectively, were performed. Atopy was defined by sensitization to at least one of five common aeroallergens (birch, grass and mugwort pollen, house dust mites, cat dander). In part of the study population investigations of spare time behaviour and skin function were carried out (including stratum corneum hydration and skin surface pH).

RESULTS

A total of 2693 girls and 2783 boys underwent a full dermatological examination of the skin and determination of sensitization. Among the girls, 8.7% demonstrated eczema clinically at the day of investigation in contrast to 6.1% of the boys. In girls, early onset eczema (< 2 years of age) was strongly related to atopy at age 5-7 years [odds ratio (OR) 3.7; 95% confidence interval (CI) 2.7-5.1], whereas late-onset eczema (> or = 2 years of age) was not (OR 1.0; 95% CI 0.7-1.5). Boys were more often atopic at the age of 5-7 years than girls (28.3% vs. 20.6%), and early and late-onset eczema were related to atopy without such a difference (OR 2.8, 95% CI 2.0-4.0; OR 1.9, 95% CI 1.3-2.8, respectively). The excess of current eczema in 5-7-year-old girls compared with boys was related to the nonatopic type. The higher susceptibility of girls in that age group to develop eczema was reflected by the skin physiological examination: even girls without eczema had significantly higher skin surface pH and lower stratum corneum hydration than boys. Additionally, questionnaire data revealed that girls more often than boys predominantly played indoors, which was associated with more eczema.

CONCLUSIONS

Atopy and eczema develop differently in boys and girls. Boys are more often atopic, whereas girls suffer significantly more often from eczema without relation to atopy. The nonatopic type of eczema in preschool girls is noticed predominantly after their second birthday. Genetic and lifestyle factors may contribute to this difference.

Polymorphisms within the CTLA4 gene are associated with infant atopic dermatitis

BACKGROUND

Atopic dermatitis (AD) is one of the most common childhood disorders. It can have a significant impact on the physical and psychological well-being of affected individuals. Although environmental triggers are important, AD also has a strong genetic component. Identifying genes associated with AD may help to understand better the basis of this disorder and its relationship with other allergic disorders such as asthma.

OBJECTIVES

Polymorphisms in the gene encoding the inhibitory CTLA4 receptor, an important regulator of T cells, are associated with asthma as well as autoimmune disorders. We have now tested whether polymorphisms in the CTLA4 gene are also associated with early childhood AD.

METHODS

A family-based cohort of 112 children and their parents was recruited from Western Sydney, Australia. All children were seen by a paediatric dermatologist and presented with AD within the first 3 years of life. Using the transmission disequilibrium test, individual and haplotypic associations with the +49 and CT60 polymorphisms in exon 1 and the 3' nontranslated DNA of the CTLA4 gene were tested.

RESULTS

Single tests of association revealed significant association of the +49(A) [P = 0.037, odds ratio (OR) 1.59, 95% confidence interval (CI) 1-2.55] and borderline significance of the CT60(A) alleles (P = 0.055, OR 1.51, 95% CI 1-2.38). Significant association of the +49(A)/CT60(A) haplotype was detected (P = 0.002, OR 1.78, 95% CI 1.2-2.65).

CONCLUSIONS

Polymorphisms within the gene encoding CTLA4 were associated with early onset infant AD. This is in agreement with findings from asthmatic cohorts, suggesting that the +49(A)/CT60(A) haplotype is a genetic risk factor common to asthma and AD.

Expression of Fas ligand and CTLA4 in adenoids has a predictive value for allergic rhinitis development in children

BACKGROUND

The balance of CD28/CTLA4-derived signals and Fas-dependent apoptosis activity is determined by the peripheral defense mechanisms and might play a role in the pathogenesis of allergy.

OBJECTIVES

The aim of the study was to investigate the expression of costimulatory and pro- and antiapoptotic molecules in adenoid T cells of children suffering from allergic rhinitis and to find out which of these molecules have a predictive value in the development of allergic rhinitis.

METHODS

The adenoids of 60 children, removed because of nasal obstruction, chronic rhinitis and recurrent respiratory infection, were evaluated. Patients were divided into two groups: group 1, suffering from chronic allergic rhinitis, and group 2, suffering from chronic rhinitis, where no specific IgE was detected, including children with a positive family history of allergy (group 2a) and children with neither a personal nor a family history of allergy (group 2b). For immunohistochemical stainings anti-CD3, anti-CD19, anti-CD4, anti-CD8, anti-CD25, anti-CD28, anti-CTLA4 (CD152), anti-bcl-2, anti-Fas, and anti-FasL antibodies were used. The number of cells expressing these molecules was identified in adenoid interfollicular spaces. The results were then analyzed in allergic and nonallergic children. During a 24-month follow-up children were re-examined for allergy and results were compared to previous immunohistochemical evaluations.

RESULTS

The expression of CD4, CD25, CD28, FasL, and CTLA4 was significantly increased in group 1 compared to group 2 (p < 0.05). However, the discriminant analysis confirmed that only CTLA4 and FasL expression fully discriminated allergic subjects from the others. During a 24-month period of observation 8 children from group 2a were also diagnosed with allergic rhinitis. All of them, especially those sensitized to mites, had an increased number of FasL+ and CTLA4+ in previously removed adenoids.

CONCLUSION

An increased number of cells with intracellular expression of FasL and CTLA4, in interfollicular spaces of adenoids, seems to be a predictive factor of the development of allergic rhinitis.

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.

Rethinking genetic models of asthma: the role of environmental modifiers

Asthma is a common, chronic disease with a complex etiology. To date, more than 35 genes have been associated with asthma or related phenotypes in multiple populations, but none of them has been shown to contribute to risk in all populations studied. We suggest that genetic susceptibility is both context dependent and developmentally regulated, and that ignoring the environmental context will miss many important associations and clues to pathogenesis. We define 'environment' broadly to include the in utero environment, maternal affection status and sex, and propose that epigenetic mechanisms are the link between our genes and our environment.

Increased expression of plasma and cell surface co-stimulatory molecules CTLA-4, CD28 and CD86 in adult patients with allergic asthma

The co-stimulatory interactions of the B7 family molecules CD80 and CD86 on antigen-presenting cells, together with their T cell counter receptors CD28 and cytotoxic T lymphocyte-associated antigen-4 (CTLA-4), modulate T lymphocyte-mediated immune responses in a reciprocal manner. To investigate whether there is altered expression and the clinical significance of soluble co-stimulatory molecules in asthmatic patients, plasma concentrations of sCTLA-4, sCD28, sCD80 and sCD86 in 51 adult allergic asthmatic adults with or without steroid treatment, and 35 sex- and age-matched control subjects were measured by enzyme-linked immunosorbent assay (ELISA). Cell surface expression of CTLA-4 and CD28 on peripheral blood mononuclear cells (PBMC) were analysed by flow cytometry. Results showed that the plasma sCTLA-4 concentration was significantly higher in all asthmatic patients while sCD28 and sCD86 concentrations were significantly higher in steroid and non-steroid treated asthmatic patients, respectively, compared with control subjects (all P < 0.01). Significantly increased cell surface expression of CD28 but not CTLA-4 on PBMC was found in asthmatic patients compared with controls (P < 0.05). The plasma concentration and cell surface expression of CTLA-4 were found to exhibit positive and significant correlations with those of CD28 (both P < 0.05). Serum total IgE concentration correlated positively and significantly with sCTLA-4 and sCD28 concentrations in allergic asthmatic patients (both P < 0.05). The increased expression of these soluble co-stimulatory molecules may reflect the dysregulation of T cell activation, thereby contributing to the immunopathogenesis of allergic asthma.

Genetics and the occupational environment

PURPOSE OF REVIEW

This article will focus on the role of risk factors including genetic factors in the development of sensitization and occupational asthma.

RECENT FINDINGS

We will review the recent literature published on the genetics of occupational asthma, especially on genes coding for class II human leukocyte antigen and on respiratory antioxidant mechanisms. We will also discuss published work on non-occupational asthma and on allergic rhinitis because this information may contribute to a better understanding of the mechanisms involved in occupational asthma and serve to confirm data obtained on the disease. To date, although some progress has been made in the field of occupational asthma genetics, most studies were based on small sample sizes, findings were not replicated, and gene-environment interactions have not yet been established.

SUMMARY

Occupational asthma is a widespread and frequent condition and has relevant long-term adverse health and economic consequences. The search for risk factors including genetic factors in the development of the disease and an understanding of the mechanisms of interaction between genes and environment are important because the identification of individuals who are susceptible to occupational asthma together with an effective control of exposure to respiratory sensitizers in the workplace may be helpful in preventing the disease.

The role of genetics in the development of asthma and atopy

PURPOSE OF REVIEW

The mapping of complex traits such as asthma and atopy is one of the most important and central areas of human genetics. This article will present an overview of the current status of genetic studies of asthma and atopy using genome screens and association studies that have occurred in the literature since January 2003.

RECENT FINDINGS

Many regions of the genome have been found to have linkage with the phenotypes of asthma and atopy. Over 70 variants in candidate genes have been reported to be associated with these phenotypes. The main regions these variants have been found are on chromosomes 2q, 5q, 6p, 11q, 12q, 16q and 17q. Five potential asthma susceptibility genes or complexes have been identified using a positional approach. These are ADAM33, DPP10, PHF11 and SETDB2, GPRA and SPINK5. It is evident that environmental factors will influence the expression of genes and the ultimate clinical phenotype of asthma and atopy.

SUMMARY

The development of asthma and atopy involves many genes and environmental factors. An understanding of their genetic basis has great implications for their management.

Association of the A/G polymorphism at position 49 in exon 1 of CTLA-4 with the susceptibility to unexplained recurrent spontaneous abortion in the Chinese population

PROBLEM

To investigate whether the A/G polymorphism at position 49 in exon 1 of cytotoxic T lymphocyte antigen-4 (CTLA-4) gene, which delivers a negative signal to T-cell activation, confers the susceptibility to unexplained recurrent spontaneous abortion in the Chinese population.

METHOD OF STUDY

A total of 168 patients with unexplained recurrent spontaneous abortion (RSA), who were treated in the Renji Hospital affiliated to the Shanghai Second Medical University, were matched against 117 women with normal pregnancy history. Case-control study to compare the frequency of G/A alleles, AA/AG/GG genotypes and A + (AA + AG) /G+ (GG + AG) phenotypes of CTLA-4 between RSA patients and controls were performed. After amplification of CTLA-4 exon-1 region by polymerase chain reaction (PCR), restriction fragment-length polymorphism (RFLP) was used to detect the polymorphism at position 49 in exon-1 of CTLA-4 gene. Statistical significance was tested by SPSS software.

RESULTS

There were dissimilar distributions of G/A alleles, AA/AG/GG genotypes and A+/G+ phenotypes of CTLA-4 between RSA patients and controls. The frequencies of G allele (P = 0.032) and GG genotype (P = 0.011) in RSA patients were significantly higher than those in controls, while the frequencies of AG genotype (P = 0.039) and A + (AA + AG) phenotype in RSA patients were decreased significantly (P = 0.011).

CONCLUSIONS

Our findings suggest that A/G polymorphism in exon-1 of CTLA-4 is associated with the immunopathogenesis of RSA, and it confers susceptibility to RSA in Chinese population.

Elevation of plasma soluble T cell costimulatory molecules CTLA-4, CD28 and CD80 in children with allergic asthma

BACKGROUND

The surface expression of T cell costimulatory molecules CTLA-4 and CD28 and their counter-ligands, B7 molecules (CD80, CD86), is differentially induced for T cell activation and expansion in allergic asthma. However, the role of their soluble forms in plasma has not yet been elucidated. In this study, we investigated whether expression is altered and whether soluble costimulatory molecules are clinically relevant in asthmatic patients.

METHODS

Plasma concentrations of soluble CTLA-4 (sCTLA-4), CD28, CD80 and CD86 in 51 children with chronic allergic asthma with or without inhaled corticosteroid treatment, and 22 sex- and age-matched control subjects were measured by enzyme-linked immunosorbent assay. Plasma total IgE concentration was measured using a microparticle immunoassay.

RESULTS

Asthmatic patients had higher logarithmic plasma total IgE concentration (IgE(log)) than healthy subjects (p < 0.0001). In non-steroid-treated patients, plasma sCTLA-4, sCD28 and sCD80 but not sCD86 concentrations were significantly higher than those of control subjects (all p < 0.05). Plasma sCD80 and sCD86 but not sCTLA-4 and sCD28 concentrations correlated significantly with IgE(log) of all subjects (p < 0.05). There were also significant positive correlations between sCTLA-4 and sCD28 (p = 0.0007), and between sCD80 and sCD86 in all asthmatic patients (p = 0.001).

CONCLUSIONS

Plasma sCTLA-4, sCD28 and sCD80 concentrations are elevated in allergic asthma. The increased expression of these soluble proteins may reflect the dysregulation of T cell activation, contributing to the immunopathogenesis of allergic asthma.

CTLA-4 polymorphisms in allergy and asthma and the TH1/ TH2 paradigm

BACKGROUND

Several genomic regions are reported to be associated with the development of asthma and allergy, including chromosome 2q33. This region harbors the candidate gene cytotoxic T-lymphocyte antigen 4 (CTLA-4), an important regulator of T-cell activation and differentiation.

OBJECTIVE

We sought to explore possible associations between CTLA-4 polymorphisms and allergy and asthma.

METHODS

Seven single nucleotide polymorphisms (SNPs; MH30, -1147CT, +49AG, CT60, JO31, JO30, JO27_1) in CTLA-4 were analyzed for associations with total serum IgE, allergic sensitization (positive skin prick test to common allergens), bronchial hyperresponsiveness (BHR) to methacholine, asthma, and lung function (FEV1 % of predicted) in 364 asthmatic families from 3 European countries.

RESULTS

Transmission disequilibrium test analysis showed that several SNPs were significantly associated with serum IgE levels, allergy, asthma, and FEV1 % predicted below 80%, but not with BHR, and CTLA-4 polymorphisms of potentially direct pathogenic significance in atopic disorders were identified.

CONCLUSION

We identified associations between 4 newly discovered SNPs in the CTLA-4 gene and serum IgE levels, allergy, asthma, and reduced lung function, but not BHR, suggesting an important role for CTLA-4 in atopy and reduced lung function in asthmatic subjects rather than asthma per se. The particular SNP alleles found positively associated with our phenotypes were recently shown to be associated negatively with autoimmune disorders. Although a skewing toward a TH1 reactivity pattern is believed to characterize autoimmune diseases, atopic diseases are considered TH2-mediated. Hence, our data suggest a role for CTLA-4 polymorphisms in determining the TH1/TH2 balance and identify CTLA-4 signaling as a potential therapeutic target in atopic disease.

Food allergy: what do we learn from animal models?

PURPOSE OF REVIEW

This review summarizes selected articles on animal models of food allergy published in 2003. The research areas that are covered include mechanistic studies, the search for new therapies, as well as screening models for hazard identification of potential allergens.

RECENT FINDINGS

Novel treatment options of both prevention and therapeutic strategies have been reported with promising results. The induction of de-sensitization to food proteins was achieved by exposure to a mixture of recombinant food allergens and T helper 1 (Th1)-skewing bacterial components. Furthermore, research in animal models has provided new insights into the role of protein structure, digestion, and gut permeability in sensitization and tolerance induction to food proteins. The Th2 hypothesis of food allergy was tested in mouse strains, linking genetic susceptibility to sensitization with differential Th1-Th2 responses. In this context, the role of the liver in development of food antigen-specific Th2 cells, and the importance of costimulatory molecules in Th2 skewing were demonstrated. Finally, rodent models to predict potential allergenicity of novel foods have been further developed using different routes of sensitization.

SUMMARY

Currently, several animal models of food allergy are used, including mouse, rat, swine, and dog. Continuing research in these models may elucidate the immunological mechanisms that underlie the sensitization and challenge phase of food allergy and may result in improved therapeutic options. Furthermore, the development of animal models to predict relative allergenicity of novel foods remains an important topic.