Genetic susceptibility to atopic dermatitis

Allergic Rhinitis in Children: An Underestimated Disease

Allergic rhinitis affects approximately 40% of children. This study aimed at determining the prevalence, sociodemographic features, comorbid illnesses, complications and quality of life in children referred to the outpatient clinic of "Allergic Rhinitis" in Penteli Children Hospital, Athens, Greece. We analyzed 590 pediatric patients referred to the outpatient clinic of "Allergic Rhinitis" in Penteli Children Hospital, Athens, Greece from 26/01/2012 to 20/11/2022. Allergic rhinitis was recorded as the one and only allergic disease in 59% of the children diagnosed with allergic rhinitis, concomitant asthma in 16% of them, atopic dermatitis in 8% and allergic conjunctivitis in 5%. 54% of asthmatic children was diagnosed allergic rhinitis, while 16% of allergic rhinitis children was diagnosed asthma. Skin tests were important diagnostic tools, not being necessary the measurement of total IgE in plasma. Eosinophils from nasal secretions were increased in 19% of the children with non-diagnostic cases and the diagnosis was local allergic rhinitis (LAR). Clinical presentations of allergic rhinitis were mainly nasal blockage, runny nose, recurrent sneezing and nasal itching. The most common complication was acute or chronic sinusitis 35%. Major associated comorbid illnesses among were tonsils hypertrophy, adenoid hypertrophy and inferior turbinate hypertrophy. Allergic rhinitis was reported in 78% of studied children and was frequently characterized by significant morbidity. Allergic rhinitis affected all paediatric age group and was peaked at age group 11-14 years and 5-7 years. There were associated epidemiological features, clinical manifestations, comorbid illnesses, complications and affectation of the quality of life in children.

Association between IL-6 polymorphisms and Atopic Dermatitis in Chinese Han children

Introduction

Atopic Dermatitis (AD) is a chronic inflammatory skin disease that affects almost 20% of children and 2 -10% of adults worldwide. Previous studies revealed that Interleukin-6 (IL-6) plays an essential role in autoimmune and chronic inflammatory diseases. This study aims to investigate the associations between IL-6 polymorphisms and AD.

Methods

Blood samples were collected from 132 AD patients and 100 controls, and single nucleotide polymorphisms (SNPs) in IL-6 (rs2069840 (C/G), rs2066992 (G/T), rs2069837 (A/G) and rs1800796 (G/C)) were analyzed using Multiplex PCR-Based Next Generation Sequencing (NGS).

Results

Results showed that the A/G genotype of IL-6/rs2069837 was significantly associated with a 1.933-fold increased risk of AD compared to those patients with A/A genotype (OR 1.933; 95%CI 1.086-3.438; p=0.024). The combined A/G-G/G genotype raised AD risk by 1.856 times compared to patients with the A/A genotype in dominant model (OR: 1.856; 95% CI: 1.056-3.261; p=0.030). No association was observed for 3 other SNPs and 4 haplotypes.

Discussion

These findings suggested that the A/G genotype of IL-6/rs2069837 was more susceptible to AD than A/A genotype in Chinese Han children, indicating the risk role of IL-6/rs2069837 in the occurrence of AD.

Hearing Assessment in Patients of Allergic Rhinitis: A Study on 200 Subjects

Allergic rhinitis (AR) is a type I hypersensitivity reaction of the nasal mucosa, primarily mediated by IgE, with a complex etiology, determined by genetic and environmental interactions. Several mechanisms by which AR affect middle ear and cause conductive hearing loss have been well described. There is paucity of data regarding involvement of inner ear in AR patients leading to sensorineural hearing loss. However, endolymphatic sac and outer hair cells have been hypothesized to be the seat of immunoreactivity. To study the audiological profile in AR and effect of AR on inner ear functions. 100 cases of AR patients (55 males, 45 females, mean age group 21-30 years) and 100 controls (65 males, 35 females, mean age group 41-50 years) were enrolled in study. All underwent thorough clinical ear, nose and throat examination, diagnostic nasal endoscopy and otoendoscopy, followed by audiological assessment including pure tone audiometry, tympanometry and oto-acoustic emission test. Hearing results of both the groups were compared and analysed statistically. Thirty two patients among case group had sensorineural hearing loss, pronounced at 4000 and 8000 Hz frequencies. 18 patients showed conductive hearing loss in the form of type B or type C tympanogram. 32 patients of AR patients showed unusual oto-acoustic emission test. We found higher prevalence of high frequency sensorineural hearing loss in pure tone audiometry and abnormal OAEs in patients having upper airway allergy. The likely seat of damage appears to be the inner ear as evidenced by recordings of OAE in allergic patients.

Water Extract of Rubus coreanus Prevents Inflammatory Skin Diseases In Vitro Models

Atopic dermatitis (AD) is a chronic inflammatory skin disease caused by immune hypersensitivity reaction. The cause of AD is unclear, but its symptoms have a negative effect on quality of life; various treatment methods to alleviate these symptoms are underway. In the present study, we aimed to evaluate in vitro antioxidant and anti-inflammatory effects of Rubus coreanus water extract (RCW) on AD. Total phenolic compounds and flavonoid content of RCW were 4242.40 ± 54.84 mg GAE/g RCE and 1010.99 ± 14.75 mg CE/g RCW, respectively. RCW reduced intracellular reactive oxygen species level and increased the action of antioxidant enzymes, such as catalase, superoxide dismutase, and glutathione peroxidase in tumor necrosis factor-α (TNF-α)/interferon-γ (IFN-γ)-stimulated HaCaT cells. Moreover, mRNA expression of the pro-inflammatory cytokines, including TNF-α, interleukin-1β, and interleukin-6, was downregulated by RCW in the TNF-α/IFN-γ-stimulated cells. The levels of inflammatory chemokines (thymus- and activation-regulated chemokine; eotaxin; macrophage-derived chemokine; regulated on activation, normal T-cell expressed and secreted; and granulocyte-macrophage colony-stimulating factor) and intercellular adhesion molecule-1 were decreased in the TNF-α/IFN-γ-stimulated HaCaT cells after RCW treatment. Additionally, the mRNA expression levels of filaggrin and involucrin, proteins that form the skin, were increased by RCW. Furthermore, RCW inhibited the nuclear factor kappa-light-chain-enhancer of the activated B cells pathway in the TNF-α/IFN-γ-stimulated HaCaT cells. Collectively, the present investigation indicates that RCW is a potent substance that inhibits AD.

Molecular Mechanisms of Atopic Dermatitis Pathogenesis

Atopic dermatitis is a chronic, non-infectious inflammatory dermatosis. Acharacteristic feature is persistent itching of the skin. The chronic, relapsing course of the disease, economic burden, and the whole family’s involvement in the treatment process immensely reduce the quality of life of patients and their families. The disease emerges as a social problem by increasing indirect costs, such as visiting a doctor, absenteeism from work and school, and avoiding social interactions. Thepathophysiology of atopic dermatitis is complex and multifactorial. It includes genetic disorders, a defect in the epidermal barrier, an altered immune response, anddisruption of the skin’s microbial balance. The numerous complex changes at thegenetic level and innate and adaptive immunity provide the basis for characterizing the various phenotypes and endotypes of atopic dermatitis. Emerging therapies rely on the action of specific molecules involved in the disease’s pathogenesis. It may be the starting point for the individualization of atopic dermatitis treatment. This paper will try to present some molecular mechanisms of atopic dermatitis and their clinical implications.

A Novel Mutation in the IL6R Gene Identified in a Family with Asthma Patients

Background: Allergic diseases, including asthma, atopic dermatitis, allergic rhinitis, and food allergies, are caused by both environmental and genetic factors. The allergic condition, where genetic factors make up the largest proportion (up to 95%), is asthma. Aim: To identify polymorphisms and mutations in potentially disease-causing genes in a family affected with allergic asthma. Methods: Whole exome sequencing of the index patient was performed via next-generation sequencing. Variants in known allergy-associated susceptibility genes were identified by comparison with the reference genome GRChr37. Results: Seven common polymorphisms and three rare mutations were identified in the allergy-susceptibility genes of the index patient. Only four of these variants co-segregated with a second patient in the same family. These variants occurred in the TENS1, NPSR1, RAD50, and IL6R genes. Discussion: The variants observed in TENS1 and NPSR1 are relatively common (minor allele frequency, MAF ∼0.4), whereas the mutation in RAD50 is rare (MAF 0.0035). The mutation identified in IL6R (S409P) has never been found before. IL6R encodes an important receptor of the inflammatory system. The mutation occurs in the intracellular domain within a tyrosine-based motif, which is required for sorting of the IL6R protein to the basolateral side of polarized cells. It is likely that this rare mutation contributes-together with the other variants-to the predisposition to asthma and other allergic diseases.

Association of IL13 genetic polymorphisms with atopic dermatitis: Fine mapping and haplotype analysis

BACKGROUND

Although previous studies had reported an important role of interleukin 13 (IL13) and its genetic polymorphisms in atopic dermatitis (AD), many of these previous reports focused on the missense variant rs20541 (Gln144Arg) without fine mapping of the gene region.

OBJECTIVE

To analyze the potential associations of other IL13 variants and their haplotypes with AD and assess total serum immunoglobulin E (IgE) levels.

METHODS

We performed fine mapping of single-nucleotide polymorphisms (SNPs) within the IL13 gene in a pilot study of 495 children with AD and 444 healthy controls. Then, we conducted a replication study of 757 children with AD and 1620 healthy controls to evaluate the association between the rs20541 variant of IL13 and AD.

RESULTS

In the pilot study, the rs20541 and rs1295685 SNPs in the 3'-untranslated region of IL13 had significant associations with AD (P < .001 and .01, respectively). In addition, 2 haplotypes (BL2_ht1 and BL2_ht2), which harbored the significant rs20541 and rs1295685 SNPs, had an association with AD (minimum P = .006). BL2_ht1 and BL2_ht2 had nominal signals associated with the total serum IgE levels (P < .05) but not with the severity of AD (P > .05). In the replication study, rs20541 was associated with the total serum IgE levels but not with the severity of AD.

CONCLUSION

An additional IL13 gene SNP, rs1295685, has a strong linkage disequilibrium with rs20541, and its haplotypes are associated with AD and the total serum IgE levels.

Chromosome 11q13.5 variant as a risk factor for atopic dermatitis in children

INTRODUCTION

Atopic dermatitis is a chronic inflammatory skin disease with a strong genetic basis. Recent GWASs have identified a single nucleotide polymorphism on chromosome 11q13.5 (rs7927894) as novel susceptibility loci of atopic dermatitis.

AIM

To evaluate the association of this genetic variant with atopic dermatitis and to investigate its possible interaction with filaggrin null mutations in children population.

MATERIAL AND METHODS

One hundred eighty-eight children less than 2 years old were screened for the variant of allele of rs7927894 on chromosome 11q13.5 and for the 4 most prevalent filaggrin mutations. The variant of allele of rs7927894 and all filaggrin mutations were genotyped by real-time PCR assays with subsequent melting curve analysis using SimpleProbe® probes.

RESULTS

The allele of rs7927894[T] was associated with a significantly increased risk of atopic dermatitis (OR = 2.21; 95% CI: 1.14-4.28; p = 0.015). Both allergic and non-allergic patient groups had rs7927894[T] allele significantly more frequently than the control group, however, the frequency of alleles did not differ in these two groups. Interestingly, when rs7927894 variant and filaggrin mutations were considered together, the risk of atopic dermatitis was the most increased in the subjects who combined both rs7927894[T] allele and filaggrin mutations (OR = 16.41; p = 0.003).

CONCLUSIONS

Our results indicate that the rs7927894 variant on chromosome 11q13.5 may play a role in the development of atopic dermatitis, but this effect seems to be independent of allergic sensitization and of the well-established filaggrin risk alleles, but may be modulated by gene-gene interactions.

Phenotype, Function, and Mobilization of 6-Sulfo LacNAc-Expressing Monocytes in Atopic Dermatitis

Mononuclear phagocytes (MPs) are important immune regulatory cells in atopic dermatitis (AD). We previously identified 6-sulfo LacNAc-expressing monocytes (slanMo) as TNF-α- and IL-23-producing cells in psoriatic skin lesions and as inducers of IFN-γ-, IL-17-, and IL-22-producing T cells. These cytokines are also upregulated in AD and normalize with treatment, as recently shown for dupilumab-treated patients. We here asked for the role of slanMo in AD. Increased numbers of slanMo were found in AD skin lesions. In difference to other MPs in AD, slanMo lacked expression of FcɛRI, CD1a, CD14, and CD163. slanMo from blood of patients with AD expressed increased levels of CD86 and produced IL-12 and TNF-α at higher amounts than CD14⁺ monocytes and myeloid dendritic cells. While CD14⁺ monocytes from patients with AD revealed a reduced IL-12 production, we observed no difference in the cytokine production comparing slanMo in AD and healthy controls. Interestingly, experimentally induced mental stress, a common trigger of flares in patients with AD, rapidly mobilized slanMo which retained their high TNF-α-producing capacity. This study identifies slanMo as a distinct population of inflammatory cells in skin lesions and as proinflammatory blood cells in patients with AD. slanMo may, therefore, represent a potent future target for treatment of AD.

Cytokine Gene Polymorphisms in Saudi Patients With Atopic Dermatitis: A Case-Control Study

The cause of atopic dermatitis (AD) is multifactorial and a number of genes including cytokines have been involved. We genotyped 315 subjects for polymorphisms in TNF-α and TNF-β and IL-10 genes. Patients had significantly higher frequency of GA genotype of TNF-α (−308 G/A) than healthy controls. Patients with AD and controls had similar distribution of A and G alleles. Genotype AA was found in 7.11% of controls while completely absent in cases. The frequencies of genotypes GG and AA of TNF-β (+252 A/G) polymorphism were higher whereas the frequency of genotype GA was significantly lower in patients than the controls. The frequencies of genotypes GG and AA of IL-10 (1082 G/A) polymorphism were significantly increased whereas genotype GA was decreased in patients than the controls. It is concluded that TNF-α (−308 G/A), TNF-β (+252 A/G), and IL-10 (−1082 G/A) polymorphisms are linked with the susceptibility of AD in Saudis and can be a risk factor.

Gene Polymorphism of Interleukin-4, Interleukin-4 Receptor and STAT6 in Children with Atopic Dermatitis in Taif, Saudi Arabia

AIM OF STUDY

This work was performed to evaluate the level of IL-4, and to clarify the role of IL-4 gene polymorphism at position cytosine -590-to-thyamine (C-590T), IL-4Rα gene polymorphism at position adenine +4679-to-guanine (A+4679G) [isoleucine-50-valine (I50V)] and STAT6 gene polymorphism at position guanine 2964-to-adenine (G2964A) in Saudi children with non-atopic dermatitis (non-AD) and atopic dermatitis (AD) to identify their role in the pathogenesis of these diseases.

SUBJECTS AND METHODS

This study included 150 children: 50 healthy children as controls, 50 with non-AD, and 50 with AD. They were subjected to full clinical examination, complete blood picture, skin prick test, and determination of serum interleukin-4 (IL-4) and total immunoglobulin-E (IgE) levels. Detection of interleukin-4 gene (C-590T), interleukin-4 receptor alpha gene (A+4679G) (I50V), and STAT6 gene (G2964A) polymorphisms were performed by PCR-based restriction fragment length polymorphism (PCR-RFLP).

RESULTS

There was a significant (P < 0.01) association between genotype and allele frequencies of IL-4Rα (A+4679G) (I50V) polymorphism in the AD group (but not non-AD group). Moreover, there was a significant association between genotype and allele frequencies of the STAT6 (G2946A) polymorphism in the non-AD (P < 0.05) and AD (P < 0.01) groups. On the other hand, there was no significant association between genotype and allele frequencies of the (C-590T) polymorphism in the non-AD group and AD group. There was a significant (P < 0.001) higher total IgE level in patients compared to the controls. Moreover, the mean values of total IgE were significantly different among the different allelic variants of (C-590T), (I50V), (G2964A) polymorphisms of IL-4, IL-4Rα, and STAT6 genes, respectively, in all the studied groups. On the other hand, there was no significant difference of serum IL-4 levels among all the studied patients, or among the different allelic variants of (C-590T), (I50V), (G2964A) polymorphisms of IL-4, IL-4Rα, and STAT6 genes, respectively.

CONCLUSION

IL-4Rα gene (I50V) and STAT6 gene (G2964) polymorphisms may play a role in development of eczema; however, the IL-4 gene polymorphism (C-590T) had no relationship with susceptibility to the disease among Saudi children.

Impact of genetic polymorphisms on paediatric atopic dermatitis

In order to investigate whether polymorphisms of genes encoding some factors of innate and adaptive immunity play a role in the development of, or protection against atopic dermatitis (AD) and condition its severity, we genotyped 33 candidate genes and 47 single nucleotide polymorphisms (SNPs) using Custom TaqMan Array Microfluidic Cards and an ABI 7900HT analyser (Applied Biosystems, Foster City, CA, USA). The study involved 104 children with AD (29 with mild-to-moderate and 75 with severe disease; 42 girls; mean age ± SD, 5.8 ± 3.3 years) and 119 healthy controls (49 girls; mean age, 4.8 ± 3.0 years). IL10-rs1800872T, TG and MBL2-rs500737AG were all significantly more frequent among the children with AD ( P = 0.015, P = 0.004 and P = 0.030), whereas IL10-rs1800896C and TC were more frequent in those without AD ( P = 0.028 and P = 0.032). The VEGFA-rs2146326A and CTLA4-rs3087243AG SNPs were significantly more frequent in the children with mild/moderate AD than in those with severe AD ( P = 0.048 and P = 0.036). IL10-rs1800872T and TG were significantly more frequent in the children with AD and other allergic diseases than in the controls ( P = 0.014 and P = 0.007), whereas IL10-rs1800896TC and C were more frequent in the controls than in the children with AD and other allergic diseases ( P = 0.0055 and P = 0.0034). These findings show that some of the polymorphisms involved in the immune response are also involved in some aspects of the development and course of AD and, although not conclusive, support the immunological hypothesis of the origin of the inflammatory lesions.

Genome-wide genetic and transcriptomic investigation of variation in antibody response to dietary antigens

Increased immunoglobulin G (IgG) response to dietary antigens can be associated with gastrointestinal dysfunction and autoimmunity. The underlying processes contributing to these adverse reactions remain largely unknown, and it is likely that genetic factors play a role. Here, we estimate heritability and attempt to localize genetic factors influencing IgG antibody levels against food-derived antigens using an integrative genomics approach. IgG antibody levels were determined by ELISA in >1,300 Mexican Americans for the following food antigens: wheat gliadin; bovine casein; and two forms of bovine serum albumin (BSA-a and BSA-b). Pedigree-based variance components methods were used to estimate additive genetic heritability (h(2) ), perform genome-wide association analyses, and identify transcriptional signatures (based on 19,858 transcripts from peripheral blood lymphocytes). Heritability estimates were significant for all traits (0.15-0.53), and shared environment (based on shared residency among study participants) was significant for casein (0.09) and BSA-a (0.33). Genome-wide significant evidence of association was obtained only for antibody to gliadin (P = 8.57 × 10(-8) ), mapping to the human leukocyte antigen II region, with HLA-DRA and BTNL2 as the best candidate genes. Lack of association of known celiac disease risk alleles HLA-DQ2.5 and -DQ8 with antigliadin antibodies in the studied population suggests a separate genetic etiology. Significant transcriptional signatures were found for all IgG levels except BSA-b. These results demonstrate that individual genetic differences contribute to food antigen antibody measures in this population. Further investigations may elucidate the underlying immunological processes involved.

Transcriptome analysis on the inflammatory cell infiltration of nonalcoholic steatohepatitis in bama minipigs induced by a long-term high-fat, high-sucrose diet

Long-term adherence to a high-fat, high-calorie diet influences human health and causes obesity, metabolic syndrome and nonalcoholic steatohepatitis (NASH). Inflammation plays a key role in the development of NASH; however, the mechanism of inflammation induced by over-nutrition remains largely unknown. In this study, we fed Bama minipigs a high-fat, high-sucrose diet (HFHSD) for 23 months. The pigs exhibited characteristics of metabolic syndrome and developed steatohepatitis with greatly increased numbers of inflammatory cells, such as lymphocytes (2.27-fold, P<0.05), Kupffer cells (2.59-fold, P<0.05), eosinophils (1.42-fold, P<0.05) and neutrophils (2.77-fold, P<0.05). High-throughput RNA sequencing (RNA-seq) was performed to explore the systemic transcriptome of the pig liver during inflammation. Approximately 18.2 gigabases of raw sequence data were generated, and over 303 million high-quality reads were assembled into 21,126 unigenes. RNA-seq data analysis showed that 822 genes were differentially expressed in liver (P<0.05) between the HFHSD and control groups. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that the process of inflammation involved the inflammatory signal transduction-related toll-like receptor, MAPK, and PPAR signaling pathways; the cytokine-related chemokine signaling, cytokine-cytokine receptor interaction, and IL2, IL4, IL6, and IL12 signaling pathways; the leukocyte receptor signaling-related T cell, B cell, and natural killer cell signaling pathways; inflammatory cell migration and invasion- related pathways; and other pathways. Moreover, we identified several differentially expressed inflammation-related genes between the two groups, including FOS, JUN, TLR7, MYC, PIK3CD, VAV3, IL2RB and IL4R, that could be potential targets for further investigation. Our study suggested that long-term HFHSD induced obesity and liver inflammation, providing basic insight into the molecular mechanism of this condition and laying the groundwork for further studies on obesity and steatohepatitis.

The A/A genotype of an interleukin-17A polymorphism predisposes to increased severity of atopic dermatitis and coexistence with asthma

INTRODUCTION

Studies have found that the interleukin-23/T helper 17 (IL-23/Th17) pathway plays an important role in the pathogenesis of atopic dermatitis (AD). Inhibition of the IL-23/Th17 pathway with monoclonal antibodies reduces skin inflammation in animal models.

AIM

To investigate the association between IL-17A and IL-23R gene single nucleotide polymorphisms (SNPs) and the development of AD in a Polish population.

METHODS

Blood samples were collected from 166 patients with AD and 160 controls. We analyzed two SNPs, -152 G/A IL-17A and 1142 G/A IL-23R, using PCR and restriction fragment length polymorphism (RFLP) analysis.

RESULTS

There was no statistically significant difference between the examined IL-17A SNP and the incidence of AD (P > 0.05 for all comparisons). Analysis of the IL-23R gene SNP showed no relationship between AD and the G/A genotype or presence of the A allele. The study did not establish any links between the IL-23R and IL-17A gene SNPs and the likelihood of developing AD resulting from gene-gene interaction. However, there was a significant relationship between the A/A genotype in the -152 G/A IL1-7A SNP and the coexistence of AD and asthma (P < 0.04). Analyzing the association between AD severity and the occurrence of IL-17A SNP, we found that subjects with the A/A genotype were at higher risk of developing moderate or severe AD (P = 0.02).

CONCLUSIONS

We found no evidence of any effect of IL-17A or IL-23R SNPs on the occurrence of AD in our Polish population. However, the A/A genotype in IL-17A was found to predispose to increased AD severity and coexistence of AD and asthma.

Swine Leukocyte Antigen-DQA Gene Variation and Its Association with Piglet Diarrhea in Large White, Landrace and Duroc

The swine leukocyte antigen class II molecules are possibly associated with the induction of protective immunity. The study described here was to investigate the relationship between polymorphisms in exon 2 of the swine DQA gene and piglet diarrhea. This study was carried out on 425 suckling piglets from three purebred pig strains (Large White, Landrace and Duroc). The genetic diversity of exon 2 in swine DQA was detected by PCR-SSCP and sequencing analysis, eight unique SSCP patterns (AB, BB, BC, CC, CD, BD, BE and DD) representing five specific allele (A to E) sequences were detected. Sequence analysis revealed 21 nucleotide variable sites and resulting in 12 amino acid substitutions in the populations. A moderate level polymorphism and significant deviations from Hardy-Weinberg equilibrium of the genotypes distribution were observed in the populations (p<0.01). The association analysis indicated that there was a statistically significant difference in the score of piglet diarrhea between different genotypes, individuals with genotype CC showed a lower diarrhea score than genotypes AB (0.98±0.09), BB (0.85±0.77) and BC (1.25±0.23) (p<0.05), and significantly low than genotype BE (1.19±0.19) (p<0.01), CC genotype may be a most resistance genotype for piglet diarrhea.

Allergic mechanisms in eosinophilic esophagitis

Eosinophilic esophagitis is rapidly increasing in incidence. It is associated with food antigen-triggered, eosinophil-predominant inflammation, and the pathogenic mechanisms have many similarities to other chronic atopic diseases. Studies in animal models and from patients have suggested that allergic sensitization leads to food-specific IgE and T-helper lymphocyte type 2 cells, both of which seem to contribute to the pathogenesis along with basophils, mast cells, and antigen-presenting cells. In this review our current understandings of the allergic mechanisms that drive eosinophilic esophagitis are outlined, drawing from clinical and translational studies in humans as well as experimental animal models.

Eosinophilic esophagitis: clinical presentation in children

Eosinophilic esophagitis (EoE) is increasing in western nations. Symptoms in infants and young children include feeding difficulties, failure to thrive, and gastroesophageal reflux. School-aged children may present with vomiting, abdominal pain, and regurgitation; adolescents and adults with dysphagia and food impaction. Delayed diagnosis increases risk of stricture formation. Children with untreated EoE have tissue changes resembling airway remodeling. Endoscopy does not always correlate. Management centers on food elimination. Approaches include skin prick and patch testing, removal of foods, or an amino acid formula diet. Long-term elimination diets can produce nutritional deficiencies and have poor adherence.

Prevalence of and risk factors for the development of atopic dermatitis in schoolchildren aged 12-14 in northwest Croatia

BACKGROUND

Atopic dermatitis is a common allergic disorder. A multifactorial background for atopic dermatitis has been suggested, with genetic as well as environmental factors influencing disease development. Our aim was to estimate the prevalence rate and associated factors for atopic dermatitis in northern Croatia using the methods of the internationally standardised ISAAC protocol.

METHODS

The study was undertaken among 12-14-year-old schoolchildren. Data were collected using standardised ISAAC written questionnaire Phase One and some selected questions from the ISAAC supplementary questionnaire completed by parents.

RESULTS

A total of 2887 children participated in the study. Estimated lifetime (ever) prevalence rate of atopic dermatitis symptoms was 7.55% and estimated 12-month prevalence rate was 5.75%. The factors found to be associated to the symptoms of atopic dermatitis ever were: positive family atopy, female gender, sleeping on feather pillow and contact with pets after age of seven, and to the symptoms in the past 12 months were: positive family atopy, female gender, sleeping on feather pillow, parasite infestation, and contact with pets in the first year of life.

CONCLUSIONS

The results of our study show that northern Croatia is a region with moderate prevalence rates of atopic dermatitis. Following risk factors were family atopy, female gender and sleeping on feather pillow. Because of controversial results of previous studies conducted on the same topic further investigations should be made.

Interactive effect of STAT6 and IL13 gene polymorphisms on eczema status: results from a longitudinal and a cross-sectional study

BACKGROUND

Eczema is a prevalent skin disease that is mainly characterized by systemic deviation of immune response and defective epidermal barrier. Th2 cytokines, such as IL-13 and transcription factor STAT6 are key elements in the inflammatory response that characterize allergic disorders, including eczema. Previous genetic association studies showed inconsistent results for the association of single nucleotide polymorphisms (SNPs) with eczema. Our aim was to investigate whether SNPs in IL13 and STAT6 genes, which share a biological pathway, have an interactive effect on eczema risk.

METHODS

Data from two independent population-based studies were analyzed, namely the Isle of Wight birth cohort study (IOW; n = 1,456) and for the purpose of replication the Swansea PAPA (Poblogaeth Asthma Prifysgol Abertawe; n = 1,445) cross-sectional study. Log-binomial regressions were applied to (i) account for the interaction between IL13 (rs20541) and STAT6 (rs1059513) polymorphisms and (ii) estimate the combined effect, in terms of risk ratios (RRs), of both risk factors on the risk of eczema.

RESULTS

Under a dominant genetic model, the interaction term [IL13 (rs20541) × STAT6 (rs1059513)] was statistically significant in both studies (IOW: adjusted P(interaction) = 0.046; PAPA: P(interaction) = 0.037). The assessment of the combined effect associated with having risk genotypes in both SNPs yielded a 1.52-fold increased risk of eczema in the IOW study (95% confidence interval (CI): 1.05 - 2.20; P = 0.028) and a 2.01-fold higher risk of eczema (95% CI: 1.29 - 3.12; P = 0.002) in the PAPA study population.

CONCLUSIONS

Our study adds to the current knowledge of genetic susceptibility by demonstrating for the first time an interactive effect between SNPs in IL13 (rs20541) and STAT6 (rs1059513) on the occurrence of eczema in two independent samples. Findings of this report further support the emerging evidence that points toward the existence of genetic effects that occur via complex networks involving gene-gene interactions (epistasis).

Interleukin (IL)-13 promoter polymorphisms (-7402 T/G and -4729G/A) condition susceptibility to pediatric severe malarial anemia but not circulating IL-13 levels

In holoendemic Plasmodium falciparum transmission areas such as western Kenya, severe malarial anemia [SMA, hemoglobin (Hb) < 6.0 g/dL, with any density parasitemia] is the most common clinical manifestation of severe malaria resulting in high rates of pediatric morbidity and mortality in these regions. Previous studies associated interleukin (IL)-13 with pathogenesis of different infectious diseases, including P. falciparum malaria. However, the functional roles of polymorphic variants within the IL-13 promoter in conditioning susceptibility to SMA remain largely unexplored. As such, the association between the IL-13 variants -7402 T/G (rs7719175) and -4729G/A (rs3091307) and susceptibility to SMA was determined in children (n = 387) presenting with clinical symptoms of falciparum malaria and resident in a holoendemic transmission region in western Kenya. Our results indicated no difference in the proportions of individual genotypes among children presenting with non-SMA (n = 222) versus SMA (n = 165). Similarly, there was no associations between the individual genotypes (-7402 T/G and -4729G/A) and SMA. Additional analyses, however, revealed that proportions of individuals with -7402 T/-4729A (TA) haplotype was significantly higher in children presenting with SMA than non-SMA group (P = 0.043). A further multivariate logistic regression analyses, controlling for confounding factors, demonstrated that carriage of the TA haplotype was associated with increased susceptibility to SMA (OR; 1.564, 95% CI; 1.023-2.389, P = 0.039). In addition, circulating levels of IL-13 were comparable between the clinical groups as well as across genotypes and haplotypes. Collectively, findings presented here suggest that haplotypes within the IL-13 promoter at -7402 T/G and -4729G/A may modulate SMA pathogenesis, but do not affect circulating IL-13 levels.

Single nucleotide polymorphisms (SNPs) in key cytokines may modulate food allergy phenotypes

Single nucleotide polymorphisms (SNPs) can play a direct or indirect role in phenotypic expression in food allergy pathogenesis. Our goal was to quantitate the expression of SNPs in relevant cytokines that were expressed in food allergic patients. SNPs in cytokine genes IL-4 and IL-10 are known to be important in IgE generation and regulation. We examined IL-4 (C-590T), IL-4Rα (1652A/G) and IL-10 (C-627A) SNPs using real-time PCR followed by restriction fragment length polymorphism (RFLP) analysis. Our results show that the AA, AG and GG genotypes for IL-4Rα (1652A/G) polymorphisms were statistically different in radioallergosorbent test (RAST) positive versus negative patients, and although no statistically significant differences were observed between genotypes in the IL-4 (C-590T) and IL-10 (C-627A) SNPs, we observed a significant decrease in IL-4 (C-590T) gene expression and increase in IL-4Rα (1652A/G) and IL-10 (C-627A) gene expression between RAST(+) versus RAST(-) patients, respectively. We also observed significant modulation in the protein expression of IL-4 and IL-10 in the serum samples of the RAST(+) patients as compared to the RAST(-) patients indicating that changes in SNP expression resulted in altered phenotypic response in these patients.

The differences in the involvements of loci of promoter region and Ile50Val in interleukin-4 receptor α chain gene between atopic dermatitis and Japanese cedar pollinosis

BACKGROUND

Atopic dermatitis (AD) and Japanese cedar pollinosis (JCP) are common chronically allergic diseases associated with the activation of T-helper 2 cells. Recent studies have shown that polymorphisms in the genes for IL-4 receptor α chain (IL4RA) may contribute to susceptibility of AD and JCP, although the differences in the involvements of loci of IL4RA gene between AD and JCP are unclear. In this study, we investigated the role of polymorphisms in IL-4RA gene in conferring susceptibility to the development of AD and/or JCP using a family analysis and an association analysis in a Japanese population.

METHODS

Five polymorphisms in the IL-4RA gene, C-3223T, T-1914C, T-890C, Ile50Val and Glu375Ala, have been genotyped using PCR-based methods in 75 trios families, including 15 AD families, 30 JCP families, and 30 families with combination of AD and JCP in the family analysis. Forty-five AD, 60 JCP and 125 control children constituted the association study.

RESULTS

The transmission disequilibrium test showed that the allele of Ile50 was significantly transmitted to children with JCP alone (p < 0.05). Haplotype analysis showed that the -3223T/Ile50 haplotype was preferentially transmitted to both AD (p < 0.01) and JCP children (p < 0.01), while that the C-3223/Ile50 haplotype was preferentially transmitted to only JCP children (p < 0.01). The association study showed that -3223T and haplotype of -3223T/Ile50 were associated with AD children, but not with JCP. Ile50 was associated with both AD and JCP.

CONCLUSIONS

Our data suggest that -3223T and the -3223T/Ile50 haplotype were risk factors for AD. Ile50 allele seems to be involved in both JCP and AD. Interactions of the IL-4RA loci may play a role both conferring susceptibility and modulating severity of AD.

Polymorphisms in the Interleukin 4, Interleukin 13, and Corresponding Receptor Genes Are Not Associated with Systemic Sclerosis and Do Not Influence Gene Expression

Objective.

Polymorphisms in the genes encoding interleukin 4 (IL4), interleukin 13 (IL13), and their corresponding receptors have been associated with multiple immune-mediated diseases. Our aim was to validate these previous observations in patients with systemic sclerosis (SSc) and scrutinize the effect of the polymorphisms on gene expression in various populations of peripheral blood leukocytes.

Methods.

We genotyped a cohort of 2488 patients with SSc and 2246 healthy controls from The Netherlands, Spain, United Kingdom, Italy, Germany, and France. Taqman assays were used to genotype single-nucleotide polymorphisms (SNP) in the following genes: (1) IL4 (−590C>T/rs2243250); (2) IL4 receptor alpha (IL4RA) (Q576R/rs1801275); (3) IL13 (R130Q/rs20541 and −1112C>T/rs1800925); and (4) IL13RA1 (43163G>A/rs6646259). The effect of these polymorphisms on expression of the corresponding genes was assessed using quantitative RT-PCR on RNA derived from peripheral blood B cells, T cells, plasmacytoid dendritic cells, monocytes, and myeloid dendritic cells. We investigated whether these polymorphisms influenced development of pulmonary complications over 15 years in patients with SSc.

Results.

None of the investigated polymorphisms was associated with SSc or any SSc clinical subtype. We did not observe any effect on transcript levels in the cell subtypes or on development of pulmonary complications.

Conclusion.

Our data showed that polymorphisms in IL4, IL13, and their receptors do not play a role in SSc and do not influence the expression of their corresponding transcript in peripheral blood cells.

The same ELA class II risk factors confer equine insect bite hypersensitivity in two distinct populations

Insect bite hypersensitivity (IBH) is a chronic allergic dermatitis common in horses. Affected horses mainly react against antigens present in the saliva from the biting midges, Culicoides ssp, and occasionally black flies, Simulium ssp. Because of this insect dependency, the disease is clearly seasonal and prevalence varies between geographical locations. For two distinct horse breeds, we genotyped four microsatellite markers positioned within the MHC class II region and sequenced the highly polymorphic exons two from DRA and DRB3, respectively. Initially, 94 IBH-affected and 93 unaffected Swedish born Icelandic horses were tested for genetic association. These horses had previously been genotyped on the Illumina Equine SNP50 BeadChip, which made it possible to ensure that our study did not suffer from the effects of stratification. The second population consisted of 106 unaffected and 80 IBH-affected Exmoor ponies. We show that variants in the MHC class II region are associated with disease susceptibility (p_raw = 2.34 × 10⁻⁵), with the same allele (COR112:274) associated in two separate populations. In addition, we combined microsatellite and sequencing data in order to investigate the pattern of homozygosity and show that homozygosity across the entire MHC class II region is associated with a higher risk of developing IBH (p = 0.0013). To our knowledge this is the first time in any atopic dermatitis suffering species, including man, where the same risk allele has been identified in two distinct populations.

Th2 Cytokines and Atopic Dermatitis

Atopic dermatitis (AD), a chronic relapsing inflammatory skin disease, is increasing in prevalence around the world. Intensive research is ongoing to understand the mechanisms involved in the development of AD and offer new treatment options for patients suffering from AD. In this review, we highlight the importance of allergic Th2 responses in the development of the disease and summarize relevant literature, including genetic studies, studies of human skin and mechanistic studies on keratinocytes and mouse models of AD. We discuss the importance of the skin barrier and review recent findings on the pro-Th2 cytokines TSLP, IL-25, and IL-33, notably their ability to polarize dendritic cells and promote Th2 responses. After a brief update on the contribution of different T-cell subsets to AD, we focus on Th2 cells and the respective contributions of each of the Th2 cytokines (IL-4, IL-13, IL-5, IL-31, and IL-10) to AD. We conclude with a brief discussion of the current gaps in our knowledge and technical limitations.

Combined occurrence of filaggrin mutations and IL-10 or IL-13 polymorphisms predisposes to atopic dermatitis

BACKGROUND

Although filaggrin mutations are presently believed to play a key role in the development of atopic dermatitis (AD), obviously also immunological factors involved in acquired immune response are important for the development of allergic inflammation.

OBJECTIVE

To assess the frequency of FLG mutations and the polymorphisms 590 C/T in the IL-4 gene, -1082A/G in the IL-10 gene and -1055C/T in the IL-13 gene in patients with AD and their correlations between severity of AD and asthma.

METHODS

R501X and 2282del4 FLG mutations and IL-4, IL-10 and IL-13 polymorphisms were assayed in 163 patients with AD of Polish origin.

RESULTS

In the Polish patients with AD, the prevalence of FLG mutations was higher in patients with AD than in the controls and 2282del4 FLG mutation was more frequent than R501X, and it was associated with a 6-fold higher risk for AD development (P < 0.001; OR: 5.76), moderate or severe disease course, early onset of asthma and palmar hyperlinearity. Significant interactions between the 2282del4 FLG mutation and the CT genotype for IL-13 or GG genotype for IL-10 and a higher risk for developing AD were demonstrated.

CONCLUSION

FLG mutation, alone and in combination with certain IL-10 or IL-13 polymorphisms, enhances the risk for the development of AD in the Polish population.

Sensitivity-related illness: the escalating pandemic of allergy, food intolerance and chemical sensitivity

The prevalence of allergic-related diseases, food intolerance, and chemical sensitivities in both the pediatric and adult population has increased dramatically over the last two decades, with escalating rates of associated morbidity. Conditions of acquired allergy, food intolerance and chemical hypersensitivity are frequently the direct sequelae of a toxicant induced loss of tolerance (TILT) in response to a significant initiating toxic exposure. Following the primary toxicant insult, the individuals become sensitive to low levels of diverse and unrelated triggers in their environment such as commonly encountered chemical, inhalant or food antigens. Among sensitized individuals, exposure to assorted inciting stimuli may precipitate diverse clinical and/or immune sequelae as may be evidenced by clinical symptoms as well as varied lymphocyte, antibody, or cytokine responses in some cases. Recently recognized as a mechanism of disease development, TILT and resultant sensitivity-related illness (SRI) may involve various organ systems and evoke wide-ranging physical or neuropsychological manifestations. With escalating rates of toxicant exposure and bioaccumulation in the population-at-large, an increasing proportion of contemporary illness is the direct result of TILT and ensuing SRI. Avoidance of triggers will preclude symptoms, and desensitization immunotherapy or immune suppression may ameliorate symptomatology in some cases. Resolution of SRI generally occurs on a gradual basis following the elimination of bioaccumulated toxicity and avoidance of further initiating adverse environmental exposures. As has usually been the case throughout medical history whenever new evidence regarding disease mechanisms emerges, resistance to the translation of knowledge abounds.

Eczema in early life: genetics, the skin barrier, and lessons learned from birth cohort studies

Eczema is a chronic inflammatory disorder of the skin that affects up to 30% of children. It often afflicts infants in the first few months of life and can be the first indicator of the atopic march. Recent results from birth cohort studies have uncovered novel information regarding genetic and environmental factors that promote the development of eczema. Birth cohort studies provide an optimal study design to elucidate these associations and prospectively track longitudinal data including exposure assessment and health outcomes from birth into early life and childhood. This is especially relevant for eczema given the age specific emergence of this disease. In this review, we will provide a general overview of pediatric eczema and discuss the important findings in the literature with respect to genetics and environmental exposures, highlighting those derived from birth cohort studies. Additionally, we will review how these relate to the atopic march, the hygiene hypothesis and the integrity of the skin barrier.

Beta defensin-1 gene (DEFB1) polymorphisms are not associated with atopic dermatitis in children and adolescents from northeast Brazil (Recife, Pernambuco)

BACKGROUND

Atopic dermatitis (AD) is a common inflammatory skin disease resulting from the interplay between environmental, immunological and genetic factors. In our study, we investigated the role of three single nucleotide polymorphisms (SNPs) at 5'-UTR of DEFB1 gene, encoding for the human beta defensin-1, on the susceptibility to develop AD in a group of Brazilian children and adolescents.

METHODS

Three SNPs, -20 G/A (rs11362), -44 C/G (rs1800972), and -52 G/A (rs1799946) at 5'-UTR of DEFB1 gene were genotyped in two groups of children and adolescents, one affected by AD (96 subjects), the other healthy (191 individuals), from northeast Brazil.

RESULTS

-44 C/G frequencies were comparable between the two groups. The -20 GG genotype was more frequent in AD subjects than in healthy controls; the -52 GG, conversely, was more frequent in healthy controls than in AD. However, both these differences did not reach statistical significance. Also, association between SNPs and AD severity has been shown. The analysis of DEFB1 haplotypes did not highlight any association of the three SNPs with AD development or disease severity.

CONCLUSIONS

Our results seem to exclude a role for the -44 C/G DEFB1 SNPs on the pathogenesis and severity of AD, while for the -20 C/G and -52 G/A, even if not statistically significant, we evidenced a slight trend for susceptibility (-20 GG) and protection (-52 GG) for the development of AD. However, as controversial findings have been reported in the literature, the role of DEFB1 in the development of AD and in the severity of the phenotype deserves further investigation.

The link between allergies and eosinophilic esophagitis: implications for management strategies

Eosinophilic esophagitis (EE) has an increased incidence of diagnosis similar to other atopic diseases. We present a recent literature review of the common features between atopic diseases (i.e., asthma, allergic rhinitis and atopic dermatitis) and EE. All of the disorders have allergen triggers and evidence of a possible Th2 inflammation at the site of disease. Murine models have also shown similar features with the importance of T cells and Th2 cytokines for the development of disease. The diseases share underlying inflammation with the potential for remodeling with an increase in TGF-beta expression in asthma and EE. However, differences do exist between the diseases in treatment and pathogenesis. For EE, there are two basic treatment options: avoidance of the food triggers or treatment of the eosinophilic inflammation with corticosteroids.

Genetics of food allergy

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Genetik des atopischen Ekzems

Das atopische Ekzem (AE) – auch atopische Dermatitis – ist eine chronisch-entzündliche Erkrankung der Haut, zu deren Charakteristika starker Juckreiz, eine gestörten Hautbarriere und die Bildung von IgE-Antikörpern (Immunglobulin E) gegen Umweltallergene zählen. Das AE ist eine multifaktoriell-polygene Erkrankung, die genetische Prädisposition und der Einfluss von Umweltfaktoren gelten seit langem als entscheidende Auslöser. Dennoch stellt die Aufdeckung der Krankheitsursachen aufgrund der Vielzahl der beteiligten Gene und Umwelteinflüsse sowie deren möglicher Interaktionen eine enorme Herausforderung für die Wissenschaft dar. Der vorliegende Beitrag gibt einen Überblick über den aktuellen Stand der Genetik des AE, über jüngste Erfolge und mögliche Probleme. Vor allem die Identifizierung einer genetischen Ursache des Hautbarrieredefekts hat unser Verständnis des AE in den letzten Jahren entscheidend vorangebracht und könnte zu neuen Ansätzen in dessen Prävention und Therapie führen.

Association of eosinophilic gastrointestinal disorders with other atopic disorders

Eosinophilic esophagitis is a chronic disease that leads to either persistent symptoms or, at times, intermittent "flares." It shares many features with other atopic diseases (asthma, allergic rhinitis, and atopic dermatitis), including the following: T helper 2 cells and eosinophils play a critical role in the pathogenesis of the disease; avoidance of allergens promotes remission of disease and symptom control; and locally applied corticosteroids provide control. Finally, most patients who have eosinophilic gastrointestinal disorders have an associated atopic disease.

Serine protease inhibitor lymphoepithelial Kazal type-related inhibitor tends to be decreased in atopic dermatitis

BACKGROUND

A pathogenic role of serine protease inhibitor lymphoepithelial Kazal type-related inhibitor (LEKTI) in atopic dermatitis (AD) is currently in intense debate. Analyses of an association between genetic polymorphisms of SPINK5 and atopic diseases revealed contradictory results. Herein, we assessed the role of LEKTI in AD at an expressional and functional level.

METHODS

The expression of LEKTI and its inhibitory capacity was measured by real-time polymerase chain reaction and hydrolytic activity assay, respectively, in keratinocyte cell cultures of three AD patients in comparison to cultures of healthy individuals (5x) and Netherton (NS) patients (3x).

RESULTS

Expression of LEKTI was significantly decreased in AD vs. healthy volunteers. Due to reduced protease inhibition, trypsin-like hydrolytic activity in AD was slightly increased, although not significantly.

CONCLUSIONS

Even though the number of investigated subjects was small and hydrolytic activity was only slightly increased, the results denote that LEKTI might be diminished in AD. The study also disclosed the necessity of functional analyses in addition to genetic investigations to gain further and more detailed insights into the role of LEKTI in AD.

Association of the histamine N-methyltransferase C314T (Thr105Ile) polymorphism with atopic dermatitis in Caucasian children

STUDY OBJECTIVE

To investigate potential associations between the histamine N-methyltransferase (HNMT) gene, HNMT, C314T (Thr105Ile) polymorphism and atopic dermatitis in a cohort of Caucasian children.

DESIGN

Prospective, multicenter, genotype-association study.

SETTING

Four academic, tertiary care medical centers within the Pediatric Pharmacology Research Unit network.

PARTICIPANTS

Two hundred forty-nine Caucasian children aged 6 months-5 years with atopic dermatitis (127 patients) or without (122 control subjects).

INTERVENTION

Buccal swabs (one swab/cheek) were performed to obtain epithelial cells for extraction of genomic DNA.

MEASUREMENTS AND MAIN RESULTS

Data were collected on severity of atopic dermatitis, oral antihistamine treatment, and treatment response through parental report. The HNMT genotypes were successfully obtained in 116 control subjects and 122 patients with atopic dermatitis. Frequencies of the T314 variant allele (0.12 vs 0.06, p=0.04) and combined CT/TT genotype (0.24 vs 0.12, p=0.02) were significantly higher in children with atopic dermatitis compared with control subjects. Children with genotypes conferring reduced HNMT activity were 2 times more likely to have atopic dermatitis than those who were homozygous for the C314 reference allele.

CONCLUSION

Increased histamine levels in patients with atopic dermatitis may result, at least in part, from reduced enzymatic inactivation via HNMT. Genetically associated reduction in histamine biotransformation may therefore contribute to the pathogenesis, persistence, and progression of atopic dermatitis. If confirmed, these data indicate that HNMT genotype might represent a common risk factor for development of atopic dermatitis, asthma, and allergic rhinitis and may be useful in identifying individuals who are candidates for early preventive pharmacotherapeutic intervention. Additional longitudinal studies will be required to assess the relationship between genotype, disease severity, and antihistamine response.

ADAM33 genetic polymorphisms and risk of atopic dermatitis among Japanese children

OBJECTIVES

ADAM33, a disintegrin and metalloproteinase 33, gene has been identified as an asthma susceptibility gene. The relationship between single nucleotide polymorphisms (SNPs) in ADAM33 and atopic dermatitis (AD) in Japanese children was examined using case-control design.

METHODS

Seven SNPs of ADAM33 (rs2853209, rs2787094, rs2280091, rs2280090, rs628977, rs597980, and rs528557) were analyzed in 140 AD cases and 258 controls aged 3 years.

RESULTS

Only rs2853209 (T>A) was significantly associated with AD risk. Sex-adjusted odds ratio (OR) for the AA versus the TT genotype was 0.55 (95% confidence interval (CI), 0.30-0.997). Consistent with the results of genotyping analysis, a haplotype carrying rs2853209 A allele was significantly associated with decreased risk of AD compared to all the other haplotypes combined (OR=0.26, 95% CI=0.08-0.69).

CONCLUSION

This is the first study to provide evidence for an association of the ADAM33 polymorphism with AD risk but the strength of this evidence is limited by our small sample size.