Positive rate of wheat allergens in the Chinese allergic population: a systematic review and meta-analysis

In recent years, the prevalence of allergic diseases has increased significantly, causing great concern, and wheat, as one of the top 8 food allergens, is a common allergy trigger. Nevertheless, reliable estimates of the positivity rate of wheat allergens in the allergic population in China are still lacking. The systematic review and meta-analysis aims to evaluate the positive detection rate of wheat allergens in the Chinese allergic population and further provide a reference for the prevention of allergy. CNKI, CQVIP, WAN-FANG DATA, Sino Med, PubMed, Web of Science, Cochrane Library, and Embase databases were retrieved. Related research and case reports about the positive rate of wheat allergen in the Chinese allergic population published from inception to June 30, 2022, were searched, and meta-analysis was performed using Stata software. The pooled positive rate of wheat allergens and 95% confidence interval were calculated by random effect models, and the publication bias was evaluated using Egger's test. A total of 13 articles were included for the final meta-analysis, in which wheat allergen detection methods involved only serum sIgE testing and SPT assessment. The results showed that the wheat allergen positivity detection rate in Chinese allergic patients was 7.30% (95% CI 5.68-8.92%). Subgroup analysis showed that the positivity rate of wheat allergens was influenced by region, but hardly by age and assessment method. The positive rates of wheat allergy in the population with allergic diseases were 2.74% (95% CI 0.90-4.58%) and 11.47% (95% CI 7.08-15.87%) in southern and northern China, respectively. In particular, the positive rates of wheat allergens were greater than 10% in Shaanxi, Henan and Nei Mongol, all of which belong to the northern region. These results suggest that wheat allergens are an important cause of sensitization in allergic populations from northern China, and therefore attention should be paid to early prevention in high-risk populations.

Low serum levels of dehydroepiandrosterone sulfate and testosterone in Albanian female patients with allergic disease

Evidence from several unrelated animal models and some studies conducted in humans, points to the immunomodulatory effects of androgens on various components of the immune system, especially on allergic disorders. This study evaluated the serum concentrations of sex hormones in women with allergy. For this purpose, blood samples were obtained from 78 participants in order to detect serum IgE concentrations, total testosterone, estradiol, progesterone, and DHEA-S. The majority of the subjects (54) in the study were consecutive patients with doctor-diagnosed allergic pathologies: 32 with allergic rhinitis, 10 with asthma and rhinitis, and 12 with skin allergies. In addition, 24 healthy volunteers were included in the research as the control group. The average age of the subjects was 32.54 years (SD ± 11.08 years, range between 4-59 years). All participants stated that they had not used any medical treatment to alleviate any of their symptoms prior to taking part in the research. They all underwent skin-prick tests for common aero-allergens, which was used as criterion for subject selection. Hence, the subjects were selected if they reacted positively to at least one aero-allergen. Their height and weight were measured in order to calculate the BMI. As a result, statistically significant differences between controls and allergic women in serum concentrations of androgens (testosterone, p = 0.0017; DHEA-S, p = 0.04) were found, which lead to the conclusion that the concentration of total serum testosterone and DHEA-S was lower in female patients with allergic diseases compared to controls.

The Spectrum of Sensitive Skin: Considerations for Skin Care in Vulnerable Populations

Sensitive skin is a multifactorial condition, where the underlying pathology is not fully understood, and the clinical signs may not always be present or obvious. Despite this challenge, there has been recent progress to understand the different subtypes of sensitive skin, as well as new methods to measure the sensorial response that may not be obvious from visual examination. Similarly, there has been progress in understanding in the management of symptoms through skin care regimens designed for sensitive skin. The implications of this new research indicate the potential of better clinical outcomes for sensitive skin sufferers, as well as regimens more personalized to different triggers in the full spectrum of sensitive skin. J Drugs Dermatol. 2019;18(1 Suppl):s68-74

Immune development and environment: lessons from Amish and Hutterite children

Children who grow up in traditional farm environments are protected from developing asthma and allergy. This 'farm effect' can be largely explained by the child's early life contact with farm animals, in particular cows, and their microbes. Our studies in Amish and Hutterite school children living on farms in the U.S. have further demonstrated that this protection is mediated through innate immune pathways. Although very similar with respect to ancestry and many lifestyle factors that are associated with asthma risk, Amish and Hutterites follow farming practices that are associated with profound differences in the levels of house dust endotoxin, in the prevalence of asthma and atopy among school children, and in the proportions, phenotypes, and functions of immune cells from these children. In this review, we will consider our studies in Amish and Hutterites children in the context of the many previous studies in European farm children and discuss how these studies have advanced our understanding of the asthma-protective 'farm effect'.

Prenatal dog-keeping practices vary by race: speculations on implications for disparities in childhood health and disease

OBJECTIVE

There is consistent evidence demonstrating that pet-keeping, particularly of dogs, is beneficial to human health. We explored relationships between maternal race and prenatal dog-keeping, accounting for measures of socioeconomic status that could affect the choice of owning a pet, in a demographically diverse, unselected birth cohort.

DESIGN

Self-reported data on mothers' race, socioeconomic characteristics and dog-keeping practices were obtained during prenatal interviews and analyzed cross-sectionally. Robust methods of covariate balancing via propensity score analysis were utilized to examine if race (Black vs White), independent of other participant traits, influenced prenatal dog-keeping.

SETTING

A birth cohort study conducted in a health care system in metropolitan Detroit, Michigan between September 2003 and November 2007.

PARTICIPANTS

1065 pregnant women (n=775 or 72.8% Black), between ages 21 and 45, receiving prenatal care.

MAIN OUTCOME MEASURES

Participant's self-report of race/ethnicity and prenatal dog-keeping, which was defined as her owning or caring for > or =1 dog for more than 1 week at her home since learning of her pregnancy, regardless of whether the dog was kept inside or outside of her home.

RESULTS

In total, 294 women (27.6%) reported prenatal dog-keeping. Prenatal dog-keeping was significantly lower among Black women as compared to White women (20.9% vs 45.5%, P<.001), and remained significantly different even after propensity score analysis was applied.

CONCLUSION

Findings suggest that there are persistent racial differences in dog-keeping not fully explained by measures of socioeconomic status. Racial differences in prenatal dog-keeping may contribute to childhood health disparities.

Stent implantation in patients with metal allergy: a systemic review and meta-analysis

OBJECTIVES

The aim of this study was to assess whether outcomes of patients with metal allergy after coronary stent implantation differ from those of patients without metal allergy.

METHODS

A meta-analysis was carried out to compare the outcome in patients who are allergic to the metal material of a stent with those who are nonallergic. A computer-based online retrieval of databases and manual searches were performed to identify articles that addressed the association between in-stent restenosis (ISR) and contact allergy to stent materials, without language restrictions. The meta-analysis was carried out with a fixed-effect model using STATA 11. Odds ratio (OR) was used as an effect size.

RESULT

Nine relevant articles, encompassing 1223 patients, were identified. Being allergic to stent material obviously increased the risk of ISR. With the fixed model, ORs for allergic patients and nonallergic patients were 2.65 (confidence interval 1.82-3.82). A subgroup analysis of race was carried out. OR in the Asian group was higher than that in the European group (3.71 vs. 2.25), which might suggest that Asians who are allergic to stent material have a higher risk of ISR than Europeans.

CONCLUSION

Allergy to stent material worsens the prognosis of patients with coronary stent implantation. New well-designed prospective clinical trials are required to confirm this relationship and to establish the indispensability of a skin patch test before coronary stent implantation.

Trends in allergic conditions among children: United States, 1997-2011

Allergic conditions are among the most common medical conditions affecting children in the United States (1-5). An allergic condition is a hypersensitivity disorder in which the immune system reacts to substances in the environment that are normally considered harmless (6,7). Food or digestive allergies, skin allergies (such as eczema), and respiratory allergies (such as hay fever) are the most common allergies among children. Allergies can affect a child's physical and emotional health and can interfere with daily activities, such as sleep, play, and attending school (8,9). A severe allergic reaction with rapid onset, anaphylaxis, can be life threatening. Foods represent the most common cause of anaphylaxis among children and adolescents (10,11). Early detection and appropriate interventions can help to decrease the negative impact of allergies on quality of life (6). This report presents recent trends in the prevalence of allergies and differences by selected sociodemographic characteristics for children under age 18 years.

Life style and home environment are associated with racial disparities of asthma and allergy in Northeast Texas children

A high prevalence and racial disparities in asthma and allergy have been observed in American children. This study aimed to identify risk factors for asthma and allergy among children, and their contribution to racial disparities in allergy prevalence. A population-based cross-sectional study was carried out among children aged 1-8 years in Northeast Texas 2008-2009. The health conditions, life style and home environment of 3766 children were surveyed by parental questionnaires through e.g. daycares, elementary school, and medical clinics. Among participants who indicated their ethnicity, 255 were Mexican-Americans, 178 Afro-Americans and 969 Caucasians. Afro-American children had a significantly higher prevalence of asthma and eczema. Caucasian had the highest prevalence of rhinitis. Compared to Mexican-American children, Afro-American and Caucasian children were breast fed shorter time, more often went to day care center, had pets and environmental tobacco smoke exposure at home more often. For all children, being at a day care center, being exposed to dampness and environmental tobacco smoke at home were strong risk factors for asthma and allergy. Central air conditioning system was associated with an increased prevalence of wheeze among Mexican-American children, while pets were associated with an increased risk of rhinitis among Afro-American and Caucasian children. Caucasian children were generally not healthier than relatively poor Mexican-American children. Differences in the prevalence of asthma and allergy between races cannot be explained by socioeconomic status only. Life style and home environmental exposures are important risk factors for asthma and allergy in Northeast Texas children.

Variability in childhood allergy and asthma across ethnicity, language, and residency duration in El Paso, Texas: a cross-sectional study

BACKGROUND

We evaluated the impact of migration to the USA-Mexico border city of El Paso, Texas (USA), parental language preference, and Hispanic ethnicity on childhood asthma to differentiate between its social and environmental determinants.

METHODS

Allergy and asthma prevalence was surveyed among 9797 fourth and fifth grade children enrolled in the El Paso Independent School District. Parents completed a respiratory health questionnaire, in either English or Spanish, and a sub-sample of children received spirometry testing at their school. Here we report asthma and allergy outcomes across ethnicity and El Paso residency duration.

RESULTS

Asthma and allergy prevalence increased with longer duration of El Paso residency independent of ethnicity and preferred language. Compared with immigrants who arrived in El Paso after entering first grade (18%), lifelong El Paso residents (68%) had more prevalent allergy (OR, 1.72; 95% CI, 1.32 - 2.24), prevalent asthma (OR, 1.75; 95% CI, 1.24 - 2.46), and current asthma (OR, 2.01; 95% CI, 1.37 - 2.95). Spirometric measurements (FEV1/FVC and FEF25-75) also declined with increasing duration of El Paso residency (0.16% and 0.35% annual reduction, respectively).

CONCLUSION

These findings suggest that a community-wide environmental exposure in El Paso, delayed pulmonary development, or increased health of immigrants may be associated with allergy and asthma development in children raised there.

Helicobacter pylori infection and allergic diseases: epidemiological study in Japanese university students

BACKGROUND AND AIM

A negative association between Helicobacter pylori infection and allergic diseases has not been consistent. The aim of this study was to examine the association between allergic diseases and H. pylori infection in Japan.

METHODS

Newly enrolled university students completed health survey questionnaires regarding general health and the presence of allergic diseases. Helicobacter pylori status was determined by the presence of serum H. pylori IgG and the presence of allergic manifestations was confirmed by interview.

RESULTS

A total of 1953 students had a routine health survey; H. pylori status was determined in 777 including 369 with allergic diseases and 408 controls. The reported frequency of allergic rhinoconjunctivitis, atopic dermatitis, urticaria, bronchial asthma and mixed diseases was 29.0%, 11.1%, 2.0%, 0.9% and 5.0%, respectively. Helicobacter pylori infection was diagnosed less frequently in the allergic group compared with controls (11.4% vs 17.6%, P = 0.015). Helicobacter pylori infection was less frequent in men with allergic diseases (OR 0.49, 95% CI 0.27-0.89).

CONCLUSION

Allergic diseases are frequent in young Japanese adults and are negatively associated with H. pylori infection especially in men.

Allergic sensitization and microbial load--a comparison between Finland and Russian Karelia

Epidemiological data have indicated that some infections are associated with a low risk of allergic diseases, thus supporting the idea (hygiene hypothesis) that the microbial load is an important environmental factor conferring protection against the development of allergies. We set out to test the hygiene hypothesis in a unique epidemiological setting in two socio-economically and culturally markedly different, although genetically related, populations living in geographically adjacent areas. The study cohorts included 266 schoolchildren from the Karelian Republic in Russia and 266 schoolchildren from Finland. The levels of total IgE and allergen-specific IgE for birch, cat and egg albumen were measured. Microbial antibodies were analysed against enteroviruses (coxsackievirus B4), hepatitis A virus, Helicobacter pylori and Toxoplasma gondii. Although total IgE level was higher in Russian Karelian children compared to their Finnish peers, the prevalence of allergen-specific IgE was lower among Russian Karelian children. The prevalence of microbial antibodies was, in turn, significantly more frequent in the Karelian children, reflecting the conspicuous difference in socio-economic background factors. Microbial infections were associated with lower risk of allergic sensitization in Russian Karelian children, enterovirus showing the strongest protective effect in a multivariate model. The present findings support the idea that exposure to certain infections, particularly in childhood, may protect from the development of atopy. Enterovirus infections represent a new candidate to the list of markers of such a protective environment. However, possible causal relationship needs to be confirmed in further studies.

Total serum immunoglobulin E levels in a case-control study in asthmatic/allergic patients, their family members, and healthy subjects from India

BACKGROUND

Total immunoglobulin E (IgE) is an important indicator of allergic disorders. However, its role in allergic patients in India has not been evaluated in relation to atopic status for a reference range as compared with healthy subjects.

OBJECTIVE

The aim of the study was to establish serum IgE levels in a diseased group, study its relationship with atopy, and to compare the same with healthy volunteers in Indian subjects.

METHODS

Four hundred and eighty asthmatics/allergic patients, 100 first-degree relatives of asthmatics, and 120 unrelated normal healthy volunteers from Delhi region were recruited for the study. Atopy was established by family history and skin test to common indigenous allergens and, total and specific IgE measurements. Statistical analysis was performed with the help of SPSS software program.

RESULTS

The mean IgE levels were the highest in asthmatic patients and the lowest in the control healthy group. IgE was significantly high in the male than the female healthy volunteers (P<0.05), but not in the diseased group. Prosopis juliflora among pollen allergens and Alternaria alternata among fungal allergens were important sensitizers in allergic patients with 34.7% and 17.7% skin positivity, respectively. Atopic status and asthma were found to be the best predictor of IgE, which was highly significant (r(2)=0.239, P<0.00001). However, at 95% confidence interval as many as 50% of asthmatic patients had their IgE values in the normal range.

CONCLUSION

The IgE levels in Indian allergic patients is significantly related to atopy, but due to wide overlap of IgE levels in patients and healthy subjects, its diagnostic significance in Indian population seems to be limited.

Allergy and ACP1 genetic polymorphism

The ACP1 (acid phosphatase locus 1) gene encodes a highly polymorphic low molecular weight protein tyrosine phosphatase (LMPTP) involved in the modulation of various signal transduction pathways including T-cell receptor. Previous studies suggest an association of this enzyme with allergic disorders. The aim of this study was to review our previous data and to confirm the association by further observations. Two new independent samples of individuals were studied from the population of Rome. ACP1 genotype was determined and history of allergic disorders was recorded. All allergic subjects had at least one positive prick test. Three-way contingency table analyses were performed by a log linear model. In all samples studied from different populations (Italian, English, and Chinese for a total of 958 subjects) we found that the proportion of allergic subjects was higher among genotypes with low enzymic activity than among genotypes with high activity. Concentration of IgE was negatively correlated with ACP1 enzymic activity. Carriers of ACP1 genotypes associated with low enzymic activity may be more susceptible to allergic disorders.

The cysteinyl-leukotriene type 1 receptor polymorphism 927T/C is associated with atopy severity but not with asthma

BACKGROUND

The cysteinyl-leukotriene receptor type 1 (CysLT1) mediates the bronchoconstrictor and pro-inflammatory actions of cysteinyl-leukotrienes (LTC4, LTD4, LTE4) in asthma and is the molecular target of the lukast class of oral anti-leukotriene drugs. We screened the CYSLTR1 gene on chromosome Xq13-21 for coding region polymorphisms, and investigated their associations with allergy and asthma.

METHODS

Solid-phase chemical cleavage was used to screen polymorphisms in the coding region of CYSLTR1. A TaqMan allelic discrimination assay was used to genotype a 927T/C SNP and oligonucleotide ligation assays were used to genotype the previously reported 617T/C and 898G/A SNPs of CYSLTR1 in 341 asthmatic families from the UK. Associations with asthma diagnosis, atopic status, serum-specific IgE and severity of allergy and asthma were examined.

RESULTS

Family-based association tests showed that the 927 T allele was associated with atopy severity, especially in female subjects, but not with asthma diagnosis or severity, atopic status, bronchial hyper-responsiveness to methacholine or forced expiratory volume in 1 s.

CONCLUSION

Mutation screening identified only one polymorphism, 927T/C, in the coding region of the CysLT1 receptor. This polymorphsim is predictive of atopy severity, but not associated with asthma.

Caesarean section delivery and the risk of allergic disorders in childhood

BACKGROUND

The composition of the intestinal flora in young children, if unfavourable, may increase the susceptibility to allergic disorders. Beneficial intestinal microbes originate from the maternal vaginal tract and thus are more likely to be transferred during vaginal births than during Caesarean sections (C-sections).

OBJECTIVE

To determine whether children born by C-section have a different risk of allergic disorders compared with those delivered vaginally. We also tested the hypothesis that the risk of allergic disorders is highest for children born after 'repeat C-sections'.

METHODS

A retrospective cohort study of 8,953 children aged 3-10 years. Children diagnosed with allergic rhinoconjunctivitis (AR), asthma, atopic dermatitis (AD), or food allergies were identified from the Kaiser Permanente Northwest Region electronic records. The children's sex, birth weight, birth order, postnatal exposure to antibiotics as well as the mothers' age, ethnicity, education, marital status, smoking status during pregnancy, and use of asthma or hayfever medications were identified through the mothers' medical records or through the Oregon Birth Registry.

RESULTS

The risk of being diagnosed with AR was significantly higher in the children born by C-section than in those delivered vaginally: adjusted odds ratio (OR)=1.37%, 95% confidence interval (CI)=1.14-1.63. Delivery by C-section was also associated with the subsequent diagnosis of asthma (OR=1.24%, 95% CI=1.01-1.53); this association was gender specific, with a positive association restricted to girls (OR for asthma in girls: OR=1.53%, 95% CI=1.11-2.10; in boys: OR=1.08%, 95% CI=0.81-1.43). There was no significant association between mode of delivery and AD. If children born in a 'repeat C-section' were considered separately the risk of being diagnosed with AR increased further (OR=1.78%, 95% CI=1.34-2.37). The same increase was noted for asthma in girls (OR=1.83%, 95% CI=1.13-2.97) but not in boys.

CONCLUSION

Caesarean sections may be associated with an increased risk of developing AR in childhood.

High levels and gender difference of exhaled nitric oxide in Chinese schoolchildren

BACKGROUND

Exhaled nitric oxide (eNO) may represent a useful noninvasive marker of airway inflammation, but data on the reference population values in schoolchildren are limited. No reference eNO study in Asian children has been published.

METHODS

Levels of eNO in a sample of 531 schoolchildren aged 11-18 years recruited from five schools (three international schools) in Hong Kong were measured online by a chemiluminescence analyser according to ERS/ATS standard. Each student also completed an International Study of Asthma and Allergic disease in Childhood questionnaire.

RESULTS

Among the children without a physician's diagnosis of asthma or symptoms of wheeze, rhinitis and eczema, there were 258 Chinese and 33 Caucasians. In control Chinese children, the eNO level (median: interquantile range) was significantly higher (P<0.001) in males (17.0 parts per billion (p.p.b.); 10.7-36.6) than in females (10.8 p.p.b.; 7.8-17.6). When compared with Caucasian control males (11.6 p.p.b.; 8.2-19.3) and females (9.1 p.p.b.; 7.5-11.9), the Chinese children had significantly higher eNO levels for both males (P=0.011) and females (P=0.037). For Chinese asthmatic males, the median eNO (interquartile range) was 39.8 p.p.b. (12.5-73.8), and for asthmatic females, 18.0 (9.6-56.3). After controlling for sex in Chinese controls, eNO did not have any significant correlation with height, weight and body mass index or body surface area.

CONCLUSIONS

This study demonstrates a gender difference of eNO level in healthy Chinese schoolchildren. When compared with Caucasians, Chinese children have significantly higher eNO levels.

Sensitization to common allergens in adults with asthma

PURPOSE

To estimate the prevalence of atopy (ie, allergen sensitization) in a sample of adult asthma outpatients.

METHODS

Population consisted of a total of 218 patients, 18 to 55 years of age, who were currently receiving care for asthma; and 13 physicians, whose specialties were Family Practice, Allergy, or Pulmonology and who were providing care to at least 10 to 15 asthma patients weekly. Patients provided a blood sample for quantification of total and allergen-specific IgE. Outcomes were the proportion of patients with atopy and the proportions of patients with elevated serum IgE specific to each of 8 specific common allergens.

RESULTS

The patients' mean age was 42 years, and 74% were women; 68% of patients met the study definition of atopy. Total serum IgE > or = 114 kU/L was observed in 48% of patients, and 59% had elevated levels of IgE specific to one or more of 8 common allergens.

CONCLUSIONS

The majority of adult asthma outpatients had evidence of atopy and most were sensitive to a specific identifiable allergen. Awareness of the high prevalence of atopy among asthma patients might improve patient management.

Associations of place of birth with asthma and wheezing in Mexican American children

BACKGROUND

There are wide global variations in the prevalence of asthma and wheezing.

OBJECTIVES

We examined the associations of place of birth with doctor-diagnosed asthma, wheezing in the past 12 months, and other allergic conditions in Mexican American children.

METHODS

The study used data on 4121 Mexican American children age 2 months to 16 years who participated in the Third National Health and Nutrition Examination Survey.

RESULTS

The risk of asthma was associated with being born in the United States after adjusting for sex, age, history of ear infection, and having a regular place for health care (odds ratio, 2.19; 95% CI, 1.09-4.40). Among children with no previous history of ear infection, US-born children were more likely to report wheezing in the past 12 months than their peers born in Mexico after controlling for confounding variables (odds ratio, 2.05; 95% CI, 1.09-3.87). Mexican American children born in the United States were more likely to have positive skin reaction to cat, house mite, Alternaria alternata , peanut, Bermuda grass, and short ragweed but were less likely to have a positive skin test to German cockroaches after adjusting for sex, age, ear infection, having a regular place for health care, and area of residence.

CONCLUSION

Our study indicated significant associations of place of birth with respiratory symptoms and allergic conditions in Mexican American children. These findings highlight the need for further studies to examine environmental factors that change by migration and explain the observed differential in the risk of asthma or wheezing.

A genome-wide screen on the genetics of atopy in a multiethnic European population reveals a major atopy locus on chromosome 3q21.3

BACKGROUND

Dissecting complex diseases in underlying distinct traits and studying these for their genetic basis might enhance the power as well as the specificity, of detection of disease genes. These phenotypes are known as intermediate phenotypes.

OBJECTIVE

We were interested in the atopic basis of asthma, and used the sensitization to mite (Dermatophagoides pteronyssinus) allergens as a pathophysiologically important intermediate phenotype.

METHODS

This time we performed a genome-wide scan based on the same already used multiethnic European population consisting of 82 nuclear families with at least two affected siblings. We carried out nonparametric as well as parametric MOD-score analyses based on the genotypes of 603 microsatellite markers.

RESULTS

In comparison with our first genome-wide candidate region search three novel regions additionally appeared to be significant. We obtained significant results for the region 2p12 with a MOD score of 3.35 and for the region 16q21 with a MOD score of 4.18. The most significant result was found for the region 3q21.3 with the same microsatellite marker, which showed significant linkage to atopic dermatitis (AD) in another study with a MOD score of 4.51 and an nonparametric linkage analysis (NPL) of 4.00.

CONCLUSION

Our findings indicate that atopy, allergic asthma, allergic rhinitis and AD on the one hand are distinct traits on both the clinical and genetic basis, but on the other hand, our results also underline that these traits are closely related diseases concerning the atopic basis of the traits.

Local adaptation and population differentiation at the interleukin 13 and interleukin 4 loci

A 25.6 kb region at chromosome 5q31, covering the entire human interleukin 13 (IL-13) and interleukin 4 (IL-4) genes, has been reported to be associated with bronchial asthma. We have examined nucleotide variations at this locus in African, European American, and Japanese populations, using 120 diallelic variants. A block of strong linkage disequilibrium (LD) (mid R:D'mid R:>0.7) spans a 10 kb region containing IL-4 in European American and Japanese populations, and is present but less clear in African samples. Two major haplotypes at IL-4 account for >80% of haplotypes in European Americans and Japanese. These haplotypes are common and quite diverged from each other and the ancestral haplotype, resulting in highly significant deviations from neutrality. F(ST) statistics show that European American and Japanese populations are unusually distinct at the IL-4 locus. The most common haplotype in the European American population is much less common in the Japanese population, and vice versa. This implies that natural selection has acted on IL-4 haplotypes differently in different populations. This selected variation at IL-4 may account for some genetic variance underlying susceptibility to asthma and other allergic diseases. The strong LD observed in the IL-4 region may allow more efficient disease-association studies using this locus.

Allergen skin weal/radioallergosorbent test relationship in childhood populations that differ in histamine skin reactivity: a multi-national survey

BACKGROUND

Histamine skin reactivity (HSR, the dimension of the skin weal elicited by histamine 10 mg/mL) is a variable that differs in children from different European countries and increases over time in the same place (Italy).

OBJECTIVE

In this epidemiologic study, we investigated to what extent differences in HSR influence the relationship between positive allergen skin prick tests (ASPTs) and serum-specific IgE concentrations.

METHODS

Between October 2001 and February 2002, 591 unselected 9-10-year-old schoolchildren drawn from five small towns in central Poland (Starachowice), central Italy (Ronciglione, Guardea) and Libya (Al-Azyzia, near the Mediterranean sea and Samno, 900 km south of the coast) were analysed for histamine, common ASPT and for serum total and specific IgE.

RESULTS

HSR differed markedly in children from the three countries (Libya>Italy>Poland) whereas serum total IgE concentrations remained the same. The prevalence of children with measurable serum specific IgE (> or = 0.35 kU) or with a positive ASPT for five common allergens was high in Italy, lower in Poland and far lower in Libya. A 3-mm ASPT weal corresponded to a serum-specific IgE concentration that was two to threefold higher in children with low HSR compared with children with high HSR (P = 0.008).

CONCLUSION

These findings suggest that HSR--a variable that differs in schoolchildren populations from the three countries studied--independently influences the results of ASPT and its influence should be considered when ASPT are assessed in international studies. The HSR differences found in the populations reported here probably reflect a complex, dynamic, environmental interaction that should be monitored in the different parts of the world.

A novel promoter polymorphism in the gene encoding complement component 5 receptor 1 on chromosome 19q13.3 is not associated with asthma and atopy in three independent populations

BACKGROUND

The inflammatory functions of complement component 5 (C5) are mediated by its receptor, C5R1, which is expressed on bronchial, epithelial, vascular endothelial and smooth muscle cells. A susceptibility locus for murine allergen-induced airway hyper-responsiveness was identified in a region syntenic to human chromosome 19q13, where linkage to asthma has been demonstrated and where the gene encoding C5R1 is localized.

OBJECTIVE

The aim of this study was to screen for novel polymorphisms in the C5R1 gene and to determine whether any identified polymorphisms are associated with asthma and/or atopy and whether they are functional.

METHODS

Single-nucleotide polymorphism (SNP) detection in the gene encoding C5R1 was performed by direct sequencing. Genotyping was performed in three populations characterized for asthma and/or atopy: (1) 823 German children from The Multicenter Allergy Study; (2) 146 individuals from Tangier Island, Virginia, a Caucasian isolate; and (3) asthma case-parent trios selected from 134 families (N=783) in Barbados. Functional studies were performed to evaluate differences between the wild-type and the variant alleles.

RESULTS

We identified a novel SNP in the promoter region of C5R1 at position -245 (T/C). Frequency of the -245C allele was similar in the German (31.5%) and Tangier Island (36.3%) populations, but higher in the Afro-Caribbean population (53.0%; P=0.0039 to <0.0001). We observed no significant associations between the -245 polymorphism and asthma or atopy phenotypes. Upon examination of the functional consequences of the -245T/C polymorphism, we did not observe any change in promoter activity.

CONCLUSION

This new marker may provide a valuable tool to assess the risk for C5a-associated disorders, but it does not appear to be associated with asthma and/or atopy.

Allergy, asthma and markers of infections among Albanian migrants to Southern Italy

BACKGROUND

Studies of immigrants represent an useful tool to determine the relative relevance of environmental vs genetic factors in causing the reported rapid increase of the prevalence of sensitization and allergic diseases.

METHODS

A total of 152 Albanian migrants to Southern Italy responded to a questionnaire based on the European Community Respiratory Health Survey (ECRHS) and 139 of them underwent skin prick test, and 61 serological assays for total IgE and IgG antibodies against Toxoplasma gondii (TG), herpes simplex virus 1 (HSV-1), hepatitis A virus (HAV) and Helicobacter pylori (HP).

RESULTS

Reported asthma was rare (2/152; 1.3%) and reported nasal allergies rather frequent (24/152; 15.8%). Sensitization to common inhalant allergens occurred in 27/139 (19.4%) subjects. The frequency of skin sensitization to pollen (P = 0.003) and that of hay fever (P = 0.004) increased with the time spent in Apulia. All the 61 sera had antibodies against HAV, 59/61 (96.7%) against HSV-1, 48/61 (78.7%) against HP and 34/61 (55.7%) against TG. The prevalence of skin sensitization and hay fever symptoms were correlated to the duration of residence in Southern Italy.

CONCLUSIONS

Data presented indicate that Albanian migrants to Italy, in spite of the low prevalence of allergic diseases and sensitization in their country of origin, manifest with time an increasing prevalence of sensitization to local allergens and nasal symptoms after immigration to Italy. This would suggest a permanent role of allergen exposure and lifestyle factors in influencing the appearance of sensitization and symptoms of allergic diseases.

Onset of allergy and asthma symptoms in extra-European immigrants to Milan, Italy: possible role of environmental factors

BACKGROUND

Allergy and asthma are typical disorders of the affluent societies. Migrants from developing to industrialized countries seem to be at increased risk of allergy and asthma development.

OBJECTIVE

To evaluate time of onset, spectrum of sensitization and clinical features in a population of extra-European immigrants to Milan, Italy, complaining of allergy and asthma symptoms.

METHODS

Data regarding 243 extra-European immigrants checked at an allergy clinic from 1994 to 2000 were collected retrospectively. The demographic data were compared with those of the extra-European immigrants living in Milan at the end of 1999.

RESULTS

The patients were complaining of asthma (63.7%), rhinoconjunctivitis (56.7%), rhinitis alone (21%) or urticaria (3%). One hundred and eighty-seven out of 222 patients (84.3%) declared they were healthy before migrating and allergy/asthma symptoms started to appear after their arrival in Italy, namely after an average period of 4 years and 7 months. The proportion of male patients was lower than the proportion of men in the extra-European immigrant population (48% vs. 55%), suggesting that in adult immigrants allergy and asthma are more common in women than in men. Furthermore, there was an over-representation of Central-South Americans attending the clinic, which seemed to be due to a genetic predisposition to allergy/asthma development. When data were analysed for single countries, a trend towards an increased risk of allergy and asthma was found in immigrants from all Central-South American countries. A skin test positivity for at least one inhalant allergen was found in 196 out of 232 patients (81%), and the spectrum of allergic sensitization was similar to that of the Italian population living in the North of Italy.

CONCLUSION

Most extra-European immigrants declared that they were healthy at home and that allergy and asthma symptoms had appeared after immigration to Milan; lifestyle and environmental factors in a western industrialized city seem indeed to facilitate allergy/asthma onset in immigrants from developing countries. Allergy/asthma risk seems to be different in different ethnic groups.

Allergen sensitization and allergen exposure in Greenlander Inuit residing in Denmark and Greenland

The aim of this study was to estimate the prevalence of allergic sensitization and possible risk factors in a genetically homogenous Inuit population living under widely differing climatic and cultural conditions. A written questionnaire and skin prick test for 10 aeroallergens were obtained from 1119 adult Greenlanders residing in Denmark, Nuuk (main city in Southern Greenland) and Uummannaq (rural settlement in Northern Greenland). Allergen exposure was assessed by pollen counts, questions on pet keeping and counts of house dust mites in dust samples. The overall prevalence of at least one positive skin prick test was 22.8% in Denmark, 10.6% in Nuuk, and 6.4% in Uummannaq. In Denmark, the total birch pollen counts were 40-1000 times higher compared to Nuuk, whereas the grass pollen count was 13-30 times higher in Denmark compared to Nuuk. Dogs were held indoor with a similar frequency in Denmark and Nuuk, but much less frequently in Uummannaq. In Denmark, house dust mites were found in 72% of house holds (>10/0.1 g dust). Less than 15% of households in Greenland had measurable levels of house dust mites. The prevalence of sensitization to aeroallergens in Inuit Greenlanders differed significantly between Denmark, Nuuk and Uummannaq. These findings correlated with the observed differences in population allergen exposure in the three regions. Furthermore, differences in lifestyle factors such as educational level, stress and ethnic self-identification seemed to be associated with the risk of allergic sensitization in Greenland.

Association of specific allergen sensitization with socioeconomic factors and allergic disease in a population of Boston women

BACKGROUND

Socioeconomic differences in allergic disease prevalence have been reported; asthma has been associated with poverty in the United States and hay fever and eczema with relative affluence elsewhere. It is not yet established to what degree such differences in disease prevalence reflect patterns of sensitization and specific allergen sensitivities.

OBJECTIVE

We analyzed specific and total IgE measurements in a sample of 458 women, enriched for allergic disease, from the metropolitan Boston area to establish the relation of allergen sensitization to markers of socioeconomic status (SES) and to the prevalence and socioeconomic pattern of allergic disease in this community.

METHODS

Total and specific IgE antibodies were measured with the UNICAP System; self-reported allergic disease, household income, education, and race-ethnicity were ascertained with a questionnaire; and a further marker of poverty (percentage living below the poverty level) in the women's area of residence was established on the basis of zip codes. Analysis was performed with SAS statistical software.

RESULTS

Markers of low SES were univariately associated with increases in total IgE, number of allergen sensitizations, and levels of specific IgE. Socioeconomic differences in sensitization to cockroach (35% vs 6% in the highest and lowest poverty areas), animal (44% vs 26%), and ragweed (49% vs 23%) allergens were most marked. Sensitization primarily to indoor inhalant allergens (not ragweed or ryegrass) were associated with an increased risk of asthma, even after adjustment for SES.

CONCLUSION

We have demonstrated a socioeconomic gradient in sensitization that concords with increased rates of asthma in less affluent communities in this population.

Polymorphisms of the IL-4, TNF-alpha, and Fcepsilon RIbeta genes and the risk of allergic disorders in at-risk infants

Polymorphisms in the TNF-alpha (A-308G), IL-4 (C-589T), and Fcalpha RIbeta (E237G) genes have been associated with asthma and related phenotypes. To determine the predictive value of these polymorphisms we have assessed their relative risk (RR) for the development of atopy, asthma, and rhinitis in a high-risk infant population that is being followed longitudinally from birth. DNA was extracted and genotyped for 373 infants and 572 parents for each polymorphism. Phenotypic data were collected for atopy and allergic diseases in the infants at 12 mo of age. The prevalence of these phenotypes in the 281 white infants was compared in each genotypic group. There were no differences in the prevalence of any phenotype between genotypes of the TNF-alpha and Fcalpha RIbeta polymorphisms. However, we found that the IL4-589*T allele was associated with "probable" asthma (RR = 4.1) and that homozygotes for the IL4-589*T allele had an increased risk for the development of rhinitis (RR = 2.4). Using the transmission disequilibrium test, an association of IL4-589*T with atopy was found. We conclude that IL-4-589*T, but not TNF-alpha-308*2 or Fcalpha RIbeta*G, is a risk factor for the development of atopy, asthma, and rhinitis by 12 mo of age.

Allergy to olive pollen: T-cell response from olive allergic patients is restricted by DR7-DQ2 antigens

BACKGROUND

We have recently described the association between the IgE antibody response to Ole e I (the major antigen from olive tree pollen) and the DR7-DQ2 haplotype in a Spanish population.

OBJECTIVE AND METHODS

Due to the linkage disequilibrium between DR7 and DQ2, and thus the difficult distinction between the role of these two antigens in the T-cell activation response, we decided to solve this question by two approaches: 1. The study of another ethnic group, individuals of Arabic origin, with a presumably distinct disequilibrium linkage between DR and DQ antigens. Genomic DNA typing was performed in 46 subjects (allergic and non-allergic) by Restriction Fragment Length Polymorphism (RFLP) and results showed that patients with specific IgE antibodies alpha-Ole e I, were DR7 and/or DQ2. These data show a similar restriction pattern to those previously described for Spanish patients. The phenotypic frequency of DR7 antigen is significantly greater than in the non-allergic population, with a corrected P (Pc) value of 0.03. 2. The analysis of the genetic requirements of Ole e I response, using T-cell lines specific for this antigen. This was first carried out by blocking the proliferative response of these T-cell lines with specific anti-human HLA class II antibodies and then testing the genetic restriction of this response using a panel of histocompatible and histoincompatible Antigen Presenting Cells (APCs). Both experiments corroborate the hypothesis that DR7 and DQ2 are implicated in the recognition of Ole e I.

Serum IgE levels and allergic spectra in immigrants to Sweden

We evaluated the allergy status of 134 immigrants from Asia, Africa, the Middle East and South America, who were referred to our clinic during the past 10 years. Fifty Swedish patients were used for comparison. When the atopy state was not taken into account, no significant difference was found between the two groups with respect to total IgE levels. However, IgE levels of non-atopic immigrants were significantly higher than the IgE levels of non-atopic Swedes. While there was no significant difference in IgE levels between atopic and non-atopic immigrants, this difference was significant in Swedish patients. In general, IgE levels of immigrants showed a decline with time and reached approximately the same levels as for the Swedish patients in 10.5 years. In the immigrant group atopic women had a considerably lower IgE level than the atopic men. Among the atopics there were no differences between sexes. In Swedes and immigrants pollen was the most common group of allergens. The spectrum of allergy in the immigrant group changed with time in Sweden, and gradually became more similar to the Swedish spectrum. Skin and/or RAST positivity to birch increased from 16% within 2.5 years to 53% after more than 10.5 years in Sweden. Our data indicate that environmental factors rather than hereditary differences determine the IgE state. Within a few years the immunologic status of immigrants adapts to the new environment.

IgE level in Saudi Arabia

IgE level was studied in Saudi patients attending the outpatient clinics or admitted into King Fahd Hospital of the University, Al-Khober, Saudi Arabia: with diseases of allergy namely bronchial asthma, allergic rhinitis and urticaria. Over the 4 years period (1982-1986) 148 patients were studied. There were 86 (58%) males and 62 (42%) females. The age distribution showed a peak in the 20-29 age group who constituted 43% of the patients seen. IgE-level was raised in 57% of patients but was within normal limits in 43%. In Saudis IgE levels are not raised in all cases presenting with diseases of allergy.