湖北汉族变应性哮喘患者GPR154基因单倍型分析

目的探讨G蛋白偶联受体154(Gprotein-coupled receptor154,GPR154)基因多态性与湖北汉族变应性哮喘易感性间的关系。方法用聚合酶链反应和限制性片段长度多态性对145例变应性哮喘患者和120名健康人群GPR154基因的SNP563704和SNP522363位点的多态性进行分析。结果(1)变应性哮喘患者SNP563704 CC、CT和TT基因型频率是0.324、0.524和0.152;与对照组相比差异无统计学意义(χ2=1·880,P>0.05);变应性哮喘组不同基因型间血清总IgE水平差异无统计学意义(F=0.714,P>0.05)。(2)变应性哮喘患者SNP522363CC、CG和GG基因型频率是0.289、0.521和0.190;与对照组相比差异无统计学意义(χ2=0.700,P>0.05);变应性哮喘组不同基因型间血清总IgE水平差异无统计学意义(F=0·083,P>0.05)。(3)对SNP522363和SNP563704进行单倍型分析,4种频率大于0.03的单倍型在哮喘组和对照组间差异有统计学意义(χ2=16.50,P<0.01)。哮喘组CT和GT单倍型频率显著高于对照组,差异有统计学意义(P=0.015;P=0.002)。结论湖北汉族变应性哮喘易感性与单个的单核甘酸多态性无关,但与SNP522363和SNP563704组成的单倍型显著相关。     

IL-4 receptor alpha chain genetic polymorphism and total IgE levels in the English population: two-locus haplotypes are more informative than individual SNPs

The IL-4RA locus encodes for the alpha chain of the IL-4 receptor, and is both a functional and positional candidate gene for atopy and allergic disease. Recently Ober et al. have shown that the study of haplotypes at multiple loci in the IL-4RA gene could be more informative than the separate study of single nucleotide polymorphisms (SNPs). One hundred and fifty subjects affected by atopic asthma and 150 healthy control subjects were studied in the English population (Oxford district). Subjects and controls were genotyped for the Ile50Val, Ser478Pro and Gln551Arg polymorphism of the IL-4 receptor alpha chain. The distribution of haplotypes 50-478 shows a highly significant association with IgE levels. In particular, the haplotype Val50/Pro478 is much less frequent in subjects with IgE levels > 100 U mL-1 than in those with IgE levels < 100 U mL-1. Furthermore, the distribution of haplotype 50-551 shows a weak association with IgE levels that is lacking for 478-551 haplotypes. A lower frequency of the Val50/Pro478 haplotype is also observed among asthmatic subjects as compared to healthy controls. With regard to individual SNPs (50 478 and 551), no significant association has been observed with IgE levels or with asthma, thus confirming the higher informative value of the haplotype analysis as compared to separate study on SNPs.     

Mutations in the high-affinity IgE receptor beta-chain are not associated with nonresponder status

BACKGROUND: Basophils of some individuals do not release histamine upon activation of their high-affinity immunoglobulin E (IgE) receptor (Fc(epsilon)RI), but do so if this receptor is circumvented for cell activation. This so-called nonresponder phenomenon is clinically relevant, because in various studies atopy was less frequent or absent in nonresponder individuals. So far, it is unknown if this phenomenon is acquired during adulthood or exists from birth on. METHODS: Histamine release was determined from isolated leucocytes stimulated with anti-IgE or calciumionophor. Also, random primed cDNA was synthesized and the open reading frame (ORF) of the Fc(epsilon)RI beta-subunit amplified and sequenced. RESULTS: In the first part of our study, we examined the role of atopic status, type of atopy, and age in a random population of 95 children of whom we found 22% to be nonresponder. None of these parameters correlated with the nonresponder status. Except for food allergy, no specific type of atopy correlated with histamine release. The mechanism underlying the nonresponder phenomenon is assumed to occur early in the signalling cascade. We hypothesized that mutations in the Fc(epsilon)RI beta-chain may be associated with the nonresponder status, and in the second part of our study sequenced the beta-subunit in 20 responders and 20 nonresponders. Two conservative and two nonconservative heterozygous one base mutations (Thr179Thr, Asp216Asp, Ile147Leu and Glu237Gly) were found in two nonresponders and one responder. Three of these mutations have not been described so far. CONCLUSION: The nonresponder phenomenon is present from birth on and genetically determined. In our population, it was not associated with age or the presence of atopy, and appeared not to be caused by mutations in the Fc(epsilon)RI beta-chain.     

Utility of the ratio of food-specific IgE/total IgE in predicting symptomatic food allergy in children

BACKGROUND: Double-blind, placebo-controlled food challenges are time-consuming, expensive and not without risk to patients. Therefore, an in vitro test that could accurately diagnose food allergy would be of great value. OBJECTIVE: To evaluate the utility of the ratio of specific immunoglobulin E (IgE)/total IgE compared with specific IgE (sIgE) alone in predicting symptomatic food allergy. METHODS: We retrospectively analysed 992 controlled oral food challenges performed in 501 children (median age 13 months). The ratio of sIgE/total IgE was calculated and tested for correlation with the outcome of food challenges. Receiver operator characteristics (ROC)-curves were performed; predicted probabilities and predictive decision points were calculated. RESULTS: A significant correlation was found between the ratio and the outcome of food challenges for cow's milk (CM), hen's egg (HE), and wheat, but not for soy. The ROC and predicted probability curves as well as sensitivity and specificity of the decision points of the ratio were similar to those of sIgE levels for CM, HE and wheat. CONCLUSION: In view of the greater effort needed to determine the ratio, without benefit compared with the sIgE alone, the calculation of the ratio of sIgE/total IgE for diagnosing symptomatic food allergy offers no advantage for CM, HE, wheat or soy. For the majority of cases controlled oral food challenges still remain the method of choice.     

Serum levels of total IgE in non-allergic children

The purpose of this study was to establish the range of total serum IgE in a healthy population lacking personal and family history of allergy, as well as the influence of genetic factors (family history of allergy), environmental factors (degree of air pollution), age, and sex on the serum IgE levels. Using a commercial enzyme immunoassay (Phadezym IgE Prist) the mean serum level of IgE was determined in 363 non-atopic children from 0 to 12 years of age. The geometric mean of serum IgE increased according to age, indicating a positive correlation between both. Higher mean values of serum IgE were found for children with a family history of allergy, than for children without (27.82 and 14.49 U/ml respectively). The percentage of variation due to age was about 94.5% in children with no family history of allergy. The mean value of serum IgE increased with the degree of air pollution in the living area (15.49 U/ml in non-polluted areas, 20.78 U/ml in very polluted areas). However, the influence of air pollution was smaller than the influence of family history on the mean values of serum IgE. The mean value of serum IgE was not modified by sex.     

Prediction of challenge test results by flour-specific IgE and skin prick test in symptomatic bakers

Background:  Wheat and rye flours are among the most important allergens causing occupational asthma. Usually, the diagnosis of baker's asthma is based on inhalation challenge tests with flours.
Aims of the study:  To evaluate the relevance of flour-specific serum immunoglobulin E (IgE) and skin prick test (SPT) in the diagnosis of baker's asthma and to define flour-specific IgE concentrations and wheal sizes that allow a prediction of the outcome of challenge testing.
Methods:  Bronchial and nasal challenge tests with wheat (rye) flour were performed in 71 (95) symptomatic bakers. Determinations of flour-specific IgE as well as SPTs were performed in all subjects. Analyses included the calculation of sensitivity, specificity, positive (PPV) and negative predictive values (NPV) at different IgE concentrations and different wheal sizes, and receiver-operating characteristics (ROC) plots with the challenge result as gold standard.
Results:  Thirty-seven bakers were positive in the challenge with wheat flour, while 63 were positive with rye flour. Depending on the flour-specific IgE concentrations (wheal size), PPV was 74–100% (74–100%) for wheat and 82–100% (91–100%) for rye flour, respectively. The minimal cut-off values with a PPV of 100% were 2.32 kU/l (5.0 mm) for wheat flour and 9.64 kU/l (4.5 mm) for rye flour. The shapes of the ROC plots were similar for wheat and rye flour.
Conclusion:  High concentrations of flour-specific IgE and clear SPT results in symptomatic bakers are good predictors for a positive challenge test. Challenge tests with flours may be avoided in strongly sensitized bakers.     

Beta2-ADR haplotypes/polymorphisms associate with bronchodilator response and total IgE in grass allergy

Association and linkage studies of beta2-adrenergic receptor (beta2-ADR) polymorphisms in relation to the expression of asthmatic phenotypes and immune regulatory mechanisms have shown inconsistent results. In order to analyse the relevance of particular combinations of single nucleotide polymorphisms (SNPs) or haplotypes of beta2-ADR gene to bronchial asthma, bronchodilator response and total immunoglobulin E (IgE) we determined by direct DNA sequencing five SNPs (in positions: -47, -20, 46, 79, 252) in a group of 180 Caucasian subjects (110 patients with grass allergy and 70 nonatopic controls). The eight different beta2-ADR haplotypes were identified, with three the most common of them representing 92% of the studied cohort. Significantly higher (pcor = 0.0045) bronchodilator response was observed in patients with homozygotic genotype 46A/A in comparison with respective homo- and hetero-zygotes. There was no significant difference in bronchodilator response when beta2-ADR haplotypes were analysed. Significantly higher (pcor = 0.0005) total IgE levels were found in patients with beta2-ADR haplotype -47T/-20T/46A/79C/252G and homozygotic carriers of 46A (pcor = 0.0015) and 79C (pcor = 0.003) genotypes. No significant associations were found in regards to asthmatic phenotype and atopy. These results indicate that depending on phenotype studied, either an individual beta2-ADR SNP or beta2-ADR haplotype might affect disease manifestation.     

High prevalence of IgE antibodies among blood donors in Sweden and Norway

BACKGROUND: Reactions after a blood transfusion could be allergic because of passive transfer of immunoglobulin E (IgE) antibodies from allergic donors. AIMS OF THE STUDY: To compare spectrum and prevalence of IgE antibodies in blood donors from Sweden and Norway. METHODS: Using the ImmunoCAP method, serum samples from 1002 blood donors from Sweden and 500 from Norway were analysed for IgE antibodies to common inhalant and food allergens and allergens common in a hospital environment, such as penicilloyl G and latex. RESULTS: As many as 23.6-27.3% of the donors had IgE antibodies to at least one of the 14 allergens tested. Of these 6.8-16.7% had extremely high concentrations, i.e. >35 kU(A)/l corresponding to 100 times the cut-off for a positive allergy test. Most donors were sensitized to pollens, dander and mite but several had very high levels of IgE antibodies to penicilloyl G, latex and peanut. The pattern of sensitizing allergens differed between Sweden and Norway. CONCLUSIONS: High serum levels of IgE antibodies to various allergens are common among blood donors and the degree of sensitization and spectrum of involved allergen varies between geographical regions. Present routines to identify IgE sensitized, potential risk, donors are not satisfactory; the sensitivity of selection procedures is about 25%.     

Polymorphisms in interleukin‐1 receptor‐associated kinase 4 are associated with total serum IgE

Background: Serum immunoglobulin E (IgE) level is recognized to be under strong genetic control, but the causal and susceptibility genes remain to be identified. We sought to investigate the association between single nucleotide polymorphisms (SNPs) in the Toll‐like receptor (TLR) signaling pathway and total serum IgE level. Methods: A population of 206 patients with severe chronic rhinosinusitis (CRS) was used. Precise phenotyping of patients was accomplished by means of a questionnaire and clinical examination. Blood was drawn for measurement of total serum IgE, as well as DNA extraction. A maximally informative set of SNPs in the TLR1, 2, 3, 4, 6, 9, 10, CD14, MD2, MyD88, IRAK4, and TRAF6 genes were selected and genotyped. Significant findings were replicated in a second independent population of 956 subjects from 227 families with asthma. Results: A total of 97 out of 104 SNPs were successfully genotyped. Three SNPs in IRAK4– rs1461567, rs4251513, and rs4251559 – were associated with total serum IgE levels (P < 0.004). In the replication sample, the same SNPs as well as the same orientation of the risk allele were associated with IgE levels (P < 0.031). Conclusions: These results demonstrate a clear association between polymorphisms in the IRAK4 gene and serum IgE levels in patients with CRS and asthma. IRAK4 may be important in the regulation of IgE levels in patients with inflammatory diseases of the airways.     

Association of prostaglandin-endoperoxide synthase 2 gene polymorphisms with asthma and atopy in Chinese children

BACKGROUND: Cyclooxygenase-2 (COX-2) plays essential roles in inflammation. Previous studies have suggested associations between prostaglandin-endoperoxide synthase 2 (PTGS2) polymorphisms and prostaglandins production in asthma. OBJECTIVE: We have investigated the effects of Chinese tagging single nucleotide polymorphisms (SNPs) of PTGS2 on asthma traits in 299 Chinese asthmatic children and 175 controls. METHODS: Plasma total and allergen-specific IgE were measured by enzyme immunoassay. PTGS2.8473T-->C in the 3'-untranslated region of exon 10 and three tag SNPs covering most of the variations in PTGS2 haplotypes in Chinese were genotyped by restriction fragment length polymorphism. RESULTS: Among the four SNPs, only PTGS2.8473 showed significant association with asthma (P = 0.034) and atopy (P = 0.005 when compared with non-atopic controls; P = 0.023 with all controls). Carriers of the C allele had a 1.5-fold (95% confidence interval: 1.01-2.30) risk of developing asthma than those homozygous for the T allele. Multivariate regression revealed significant correlations between PTGS2.8473 and forced expiratory volume in 1 s (FEV(1); P = 0.002) and peak expiratory flow rate (PEFR; P = 0.001) with age and gender adjusted. Patients with the C allele of PTGS2.8473 had significantly lower FEV(1) (median: 90.0%vs 98.0%; P = 0.0047) and PEFR (70.0%vs 73.5%; P = 0.0065) than those homozygous for the T allele. No significant association between plasma total and allergen-specific IgE and these SNPs or with their haplotypes was found. CONCLUSIONS: PTGS2.8473 polymorphism is associated with asthma, atopy and lung function but not plasma IgE in Chinese children. This may help to explore the pharmacogenetics of COX-2 inhibitors.     

Association between first-degree familial predisposition of asthma and atopy (total IgE) in newborns

BACKGROUND: It is generally thought that infants with a first-degree familial predisposition of asthma are at higher risk of developing asthma than infants without predisposition. OBJECTIVE: To investigate whether there is an association between being at high risk for developing asthma and increased level of total IgE in newborns and whether total IgE is influenced by gender, family size, birth season, maternal smoking, birth weight, gestational age, and maternal diet. METHODS: Two hundred and twenty-one high risk and 308 low-risk infants were prenatally selected in a 5-year-period. Three to 5 days after birth, the total IgE was measured in capillary heel blood. RESULTS: Data on total IgE and first-degree familial predisposition were available for 170 high-risk and 300 low-risk infants. There was a statistically significant relationship between being at high-risk (maternal asthma) and increased levels of total IgE in newborns (total IgE cut-off levels: 0.6-0.9 IU/mL (odds ratio (OR)=2.1, 95% confidence interval (CI): 1.2-3.7 to 3.0, 95% CI: 1.5-5.9)), between being born in autumn and increased levels of total IgE in newborns [total IgE cut-off levels: 0.5-0.6 IU/mL (OR=2.5, 95% CI: 1.2-5.1 to 2.5, 95% CI: 1.2-5.4)] and between maternal vitamin supplements intake and decreased levels of total IgE in newborns (total IgE cut-off level: 0.9 IU/mL (OR=0.5, 95% CI:0.3-1.0)). There was no interaction between the effects of maternal asthma and birth season on total IgE, as well as between the effects of maternal asthma and maternal vitamin supplements intake. Gender, family size, maternal smoking, birth weight, and gestational age did not influence the associations. CONCLUSION; Being at high-risk of asthma (maternal asthma) and birth season are positively associated with the presence of increased levels of total IgE at birth, whereas maternal vitamin supplements intake is negatively associated with the presence of total IgE at birth.     

Association between genetic variations in prostaglandin E2 receptor subtype EP3 gene (Ptger3) and asthma in the Korean population

BACKGROUND: Recent investigations suggest that prostaglandin E2 (PGE2) is important in the pathogenesis of not only aspirin-intolerant asthma but also asthma unrelated to aspirin intolerance. OBJECTIVES: This study was conducted to evaluate the effects of variations in the gene coding PGE2 receptor subtype EP1-4 (Ptger1-4) on the risk of asthma in the Korean population. METHODS: Nineteen single nucleotide polymorphisms (SNPs) were selected after re-sequencing Ptger1-4 and were genotyped in 480 asthmatics and 140 healthy controls, who were randomly recruited. RESULTS: By logistic regression analyses controlling for age and sex, 1388T>C in Ptger3 was found to be significantly associated with asthma [P=0.002, odds ratio (95% confidence interval)=0.63 (0.46-0.85) in the allele model], and this remained significant after applying the Bonferroni correction. In terms of haplotype, the frequency of the C-C-A-A haplotype in Ptger3 was significantly lower in asthmatics than in healthy controls (P=0.004). Moreover, the prevalence of this haplotype was significantly lower in moderate-to-severe asthmatics than in mild asthmatics (P=0.045; mild vs. moderate and P=0.034; mild vs. severe). However, no association was found between any genetic variation in Ptger1, Ptger2, or Ptger4 and asthma. CONCLUSION: The present study demonstrated that genetic variations in Ptger3 are significantly associated with the risk and severity of asthma in the Korean population.     

Human dendritic cell 1 and dendritic cell 2 subsets express FcepsilonRI: correlation with serum IgE and allergic asthma

BACKGROUND: Type 1 dendritic cells (DC1) express the high-affinity IgE receptor (FcepsilonRI); however, the regulation of FcepsilonRI expression by DCs is not well understood. Type 2 DC (DC2) expression of FcepsilonRI has not been demonstrated. OBJECTIVE: We hypothesized that DC2 cellsalso express FcepsilonRI and that expression of FcepsilonRI by the DC1 and DC2 subsets correlates with serum IgE and allergic asthma disease status. METHODS: To test these hypotheses, we quantitated FcepsilonRI alpha chain expression by the peripheral blood precursor DC1 (pDC1) and pDC2 subsets by using flow cytometry. RESULTS: FcepsilonRI was expressed by the pDC1 and pDC2 subsets, as well as tissue DCs from tonsils. Relative FcepsilonRI expression by basophil, pDC1, and pDC2 subsets was 12:6.5:1, respectively. In both pDC subsets, FcepsilonRI expression was significantly greater in allergic asthmatic subjects than in nonatopic control subjects. pDC1 and pDC2 expression of FcepsilonRI was highly correlated to serum IgE concentration. The pDC1, pDC2, and basophil subsets demonstrated a similar magnitude of increase in FcepsilonRI expression relative to changes in serum IgE. CONCLUSIONS: FcepsilonRI expression is characteristic of both the DC1 and DC2 subsets. Furthermore, FcepsilonRI expression by these cells is highly correlated to serum IgE and to basophil FcepsilonRI expression and is greater in subjects with allergic asthma. These data support the concept that novel therapeutic approaches directly targeted at FcepsilonRI expression would affect both the sensitization and the effector phases of the allergen-specific immune response.     

Relationships between specific serum IgE, cytokines and polymorphisms in the IL-4, IL-4Ralpha in patients with penicillins allergy

BACKGROUND: Excessive production of interleukin (IL)-4, IL-13 and interferon (IFN)-gamma is thought to be important in the development of allergic disease and atopy. Several investigators have linked the IL-4 and IL-4R genes to allergic disease and atopy. The aim of this study is to further explore the mechanism of penicillins allergy and evaluate the possible role of the IL-4 C-589T and IL-4RalphaQ576R polymorphisms in modulating the allergic responses to penicillins. METHODS: Radioallergosorbent test (RAST) was used to detect eight kinds of specific immunoglobulin E (IgE) to penicillins in serum. Serum levels of IL-4, IL-13 and IFN-gamma were measured by using enzyme-linked immunosorbent assay (ELISA). The IL-4 C-589T and IL-4RalphaQ576R polymorphisms were genotyped by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). RESULTS: Compared with control subjects, there were significantly higher levels of IL-4, IL-13 and IFN-gamma in allergic patients with positive specific IgE (P < 0.01), and the lower levels of IL-4 and IFN-gamma were observed in allergic patients with negative specific IgE (P < 0.05). We found a growing trend of IL-4 and IL-13 levels with the kind increasing of positive specific IgE, and even there were significant correlations between the three kinds of cytokines and many kinds of specific IgE (P < 0.05). The IL-4Ralpha*Q576 allele was significantly increased in patients with penicillins allergy compared with control subjects (P < 0.01). Furthermore, the allele was strongly associated with increased serum-specific benzylpenicilloyl (BPO)-, phenoxomethylpenicillanyl (PVA)- or ampicillanyl (APA)-IgE levels in patients with positive specific IgE (P < 0.05). CONCLUSIONS: These data suggest that IL-4, IL-13 and IFN-gamma play an important roles in penicillins allergy. The IL-4RalphaQ576R polymorphism may involve in the development of penicillins allergy, and through modulating specific serum IgE levels.     

TLR4 Asp299Gly、Thr399Ile基因多态性对变应性哮喘的发病及IgE水平的影响

目的　探讨TLR4 (toll likereceptor 4 )Asp2 99Gly、Thr399Ile基因多态性对变应性哮喘的发病和血浆IgE水平的影响。方法　利用聚合酶链反应 限制性片段长度多态性分析技术 (PCR RFLP) ,对 1 97例变应性哮喘患者和 1 5 6例健康人进行TLR4的Asp2 99Gly、Thr399Ile两位点的基因型检测。同时利用免疫发光法检测血浆IgE的水平。结果　 1 97例变应性哮喘患者TLR4基因Asp2 99Gly位点Asp Asp、Asp Gly和Gly Gly的基因型频率为 0 .81 7、0 .1 4 7和 0 .0 36 ,与正常对照组相比差异无统计学意义 (χ2 =0 .0 32 ,P =0 .984 ) ;但变应性哮喘患者Gly Gly、Asp Gly基因型血浆总IgE对数值 ( x±s:2 .6 1 5± 0 .6 0 0 1 ,n =36 )与Asp Asp基因型血浆总IgE对数值 ( x±s:2 .2 4 0± 0 .6 894 ,n =1 6 1 )相比较高 ,差异有统计学意义 (P =0 .0 0 2 )。TLR4基因Thr399Ile位点Thr Thr、Thr Ile和Ile Ile的基因型频率为 0 .970、0 .0 2 0和 0 .0 1 0 ,与正常对照组相比差异无统计学意义 (χ2 =0 .6 2 0 ,P =0 .733) ;变应性哮喘患者Ile Ile、Thr Ile基因型血浆总IgE对数值 ( x±s:2 .4 1 7± 0 .4 4 2 3,n =6 )与Thr Thr基因型血浆总IgE对数值 ( x±s:2 .30 5± 0 .6 94 9,n =1 91 )相比差异无统计学意义 (P =0 .5 71 )。     

Geohelminth infections: a review of the role of IgE and assessment of potential risks of anti-IgE treatment

Geohelminth infections are major parasitic infections with a worldwide distribution. Immunoglobulin E (IgE) is considered to play a central role in protective immunity against these parasites although the evidence from experimental animal models infected with helminth parasites and treated with anti-IgE antibodies and from observational studies in human populations of the immunologic correlates of protective immunity against helminths do not support a critical role for IgE in mediating protection against helminths. Anti-IgE treatment of human allergic disorders using a humanized monoclonal IgE antibody (omalizumab, Xolair) has been approved for clinical use in the USA and Europe and there is concern that this treatment may be associated with increased morbidity in populations exposed to helminth infections. A recently published randomized controlled trial investigating the risk of geohelminth infections in allergic patients receiving omalizumab in Brazil has provided some evidence that omalizumab may not be associated with increased morbidity attributable to these parasites. This review examines the evidence for a role of IgE in protective immunity against helminth parasites, discusses the findings of the randomized controlled trial, assesses the potential risks and provides recommendations for anti-IgE treatment in groups of allergic patients with different exposure risks for helminth infections.