Lack of association between atopic eczema/dermatitis syndrome and polymorphisms in the promoter region of RANTES and regulatory region of MCP-1

Association between CCL5, CCL11, and CCL17 polymorphisms and atopic dermatitis risk: A systematic review and meta-analysis

BACKGROUND

Atopic dermatitis (AD) is a common and recurrent inflammatory disease with strong genetic susceptibility. The abnormal production of chemokines plays an important role in the occurrence and development of AD.

METHODS

A comprehensive online literature search was performed in databases of China National Knowledge Infrastructure, Wanfang, VIP China Science and Technology Journal Database, China Biomedical Literature Database, PubMed, Embase and Cochrane Library to retrieve relevant articles published from January 2000 to October 2022. The odds ratio (OR) with its 95% confidence interval (CI) was employed to calculate this relationship.

RESULTS

A total of 7 studies were finally screened out, including 1316 AD patients and 1099 controls. There were 3 studies for CC chemokine ligand 5 (CCL5) polymorphisms, 2 for CCL11 polymorphisms, and 2 for CCL17 polymorphisms, respectively. The meta-analysis revealed a significant association between the CCL5 - 403G/A polymorphism and AD under the allelic model (A vs G: OR = 1.25, 95% CI = 1.02-1.52, P = .03), heterozygous model (AG vs GG: OR = 1.40, 95% CI = 1.08-1.80, P = .01) and dominant model (AA + AG vs GG: OR = 1.38, 95% CI = 1.08-1.76, P = .01) in a fixed-effect model. The allelic model (G vs C: OR = 1.46, 95% CI = 1.07-1.98, P < .01) and dominant model (GG + GC vs CC: OR = 1.74, 95% CI = 1.23-2.47, P < .001) of the CCL5 - 28C/G polymorphism were also associated with an increased risk of AD. However, this significant association was not found in other alleles and genotypes (P > .05).

CONCLUSION

Our results show that the A allele, AG and AA + AG genotypes of the CCL5 - 403G/A polymorphism, the G allele and GG + GC genotype of the CCL5 - 28C/G polymorphism are risk factors for AD. Future studies with large population are still needed to further explore those correlations.

A Preventive Role of RANTES Genetic Variation against Undifferentiated Schizophrenia

AIM

Due to conflicting data from relevant studies, evidence for chemokine alterations in the pathophysiology of schizophrenia (Scz) remains inconclusive. Thus, we aimed to investigate the impact of rs2107538, rs2280788, and rs2280789 polymorphisms in CCL5 gene, as well as rs333 within CCR5 gene and the development of Scz in a Tunisian cohort.

METHODS

We performed a case-control study composed of 200 patients and 200 controls using RFLP-PCR.

RESULTS

Among the analyzed polymorphisms, only rs2107538 imparted protection against Scz and more specifically to male sex. This protective effect remained valid for the undifferentiated form. Moreover, this SNP had an impact on patients' symptomatology. When focusing on haplotypes, we noticed that the rs2107538-rs2280788-rs2280789 ACT genetic combination, with only one mutated allele rs2107538A, displayed reduced frequency in both Scz (as a whole group) and undifferentiated subtype. The haplotype distribution profile implies that the A allele at rs2107538 could induce a protective effect by increasing RANTES production.

CONCLUSION

Additional independent analyses are required to corroborate these findings and elucidate the functional implications of the discovered preventing genotypes and haplotypes in Scz.

Quantitative analysis and anti-inflammatory effects of Gleditsia sinensis thorns in RAW 264.7 macrophages and HaCaT keratinocytes

Gleditsia sinensis thorns have traditionally been used to treat edema and carbuncles and drain abscesses. In the present study, a simultaneous analysis of four flavonoids [(+)‑catechin, (‑)‑epicatechin, eriodictyol and quercetin] and two phenolic compounds (caffeic acid and ethyl gallate), obtained from a 70% ethanol extract of G. sinensis, was performed using high‑performance liquid chromatography‑photodiode array techniques. In addition, the inhibitory activities of the solvent fractions from a G. sinensis extract and its major constituents on the lipopolysaccharide‑stimulated production of inflammatory mediators by macrophage RAW 264.7 cells and the tumor necrosis factor (TNF)‑α and interferon (IFN)‑γ (TI)‑stimulated production of chemokines by HaCaT keratinocyte cells were investigated. The established analytical method showed high linearity, with a correlation coefficient of ≥0.9998. The limits of detection and quantification of the six compounds were 0.037‑0.425 and 0.124‑1.418 µg/ml, respectively. The ethyl acetate fraction inhibited nitric oxide and prostaglandin E2 production in RAW 264.7 cells and the production of thymus‑ and activation‑regulated chemokine (TARC) in HaCaT cells more than did the other fractions. Furthermore, the six compounds reduced the production of TARC, macrophage‑derived chemokine and regulated on activation normal T‑cell expressed and secreted in TI‑stimulated HaCaT cells; in particular, ethyl gallate and quercetin exhibited a significant dose‑dependent inhibition. Further elucidation of the signaling pathways involved in the T‑helper cell 2 chemokine inhibition by G. sinensis is necessary to facilitate the design of therapeutic agents for the inflammatory response.

CCL5 as a potential immunotherapeutic target in triple-negative breast cancer

Breast cancer (BC) is a leading cause of mortality among women in the world. To date, a number of molecules have been established as disease status indicators and therapeutic targets. The best known among them are estrogen receptor-α (ER-α), progesterone receptor (PR) and HER-2/neu. About 15%-20% BC patients do not respond effectively to therapies targeting these classes of tumor-promoting factors. Thus, additional targets are strongly and urgently sought after in therapy for human BCs negative for ER, PR and HER-2, the so-called triple-negative BC (TNBC). Recent clinical work has revealed that CC chemokine ligand 5 (CCL5) is strongly associated with the progression of BC, particularly TNBC. How CCL5 contributes to the development of TNBC is not well understood. Experimental animal studies have begun to address the mechanistic issue. In this article, we will review the clinical and laboratory work in this area that has led to our own hypothesis that targeting CCL5 in TNBCs will have favorable therapeutic outcomes with minimal adverse impact on the general physiology.

The rs1024611 regulatory region polymorphism is associated with CCL2 allelic expression imbalance

CC chemokine ligand 2 (CCL2) is the most potent monocyte chemoattractant and inter-individual differences in its expression level have been associated with genetic variants mapping to the cis-regulatory regions of the gene. An A to G polymorphism in the CCL2 enhancer region at position -2578 (rs1024611; A>G), was found in most studies to be associated with higher serum CCL2 levels and increased susceptibility to a variety of diseases such as HIV-1 associated neurological disorders, tuberculosis, and atherosclerosis. However, the precise mechanism by which rs1024611influences CCL2 expression is not known. To address this knowledge gap, we tested the hypothesis that rs1024611G polymorphism is associated with allelic expression imbalance (AEI) of CCL2. We used haplotype analysis and identified a transcribed SNP in the 3'UTR (rs13900; C>T) can serve as a proxy for the rs1024611 and demonstrated that the rs1024611G allele displayed a perfect linkage disequilibrium with rs13900T allele. Allele-specific transcript quantification in lipopolysaccharide treated PBMCs obtained from heterozygous donors showed that rs13900T allele were expressed at higher levels when compared to rs13900C allele in all the donors examined suggesting that CCL2 is subjected to AEI and that that the allele containing rs1024611G is preferentially transcribed. We also found that AEI of CCL2 is a stable trait and could be detected in newly synthesized RNA. In contrast to these in vivo findings, in vitro assays with haplotype-specific reporter constructs indicated that the haplotype bearing rs1024611G had a lower or similar transcriptional activity when compared to the haplotype containing rs1024611A. This discordance between the in vivo and in vitro expression studies suggests that the CCL2 regulatory region polymorphisms may be functioning in a complex and context-dependent manner. In summary, our studies provide strong functional evidence and a rational explanation for the phenotypic effects of the CCL2 rs1024611G allele.

Association between the monocyte chemoattractant protein-1 -2518G/A gene polymorphism and acute myocardial infarction patients among Egyptian population

The aim of the present study was to investigate the possible association between the -2518G/A polymorphism of the monocyte chemoattractant protein-1 (MCP-1) gene and acute myocardial infarction (MI) in a sample of the Egyptian population. A total of 30 Egyptian patients with coronary artery disease (CAD) manifested as acute myocardial infarction (MI) for the first time and 25 unrelated healthy control individuals were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The proportion of G/A and G/G genotypes were significantly higher in the acute MI group than the control group (P < 0.05). The acute MI patients group showed a significant higher frequency of the G allele compared to the controls (P < 0.05). Analysis of the relationship between the G/A, G/G genotypes and A/A genotype acute MI group regarding the conventional risk factors showed statistical significant difference regarding age, total cholesterol, low-density lipoprotein and high-density lipoprotein (P < 0.05), but there was no significant relationship regarding sex, smoking, history of diabetes mellitus, hypertension, obesity, body mass index (BMI) and triglyceride, but we observed that the percentage of men was higher than the percentage of women in both G/A, G/G genotypes and A/A genotype acute MI patients. Also, among our patients, the percentage of smokers, diabetics, hypertensive, and obesity and the mean of BMI and triglyceride were higher in the G/A, G/G genotypes acute MI patients than that in A/A genotype acute MI patients. In conclusion, our study indicated that there was a significant association between the MCP-1 -2518G/A polymorphism and acute MI in the Egyptian population, but this significant association is dependent on the presence of MI risk factors.

An update on the genetics of atopic dermatitis: scratching the surface in 2009

A genetic basis for atopic dermatitis (AD) has long been recognized. Historic documents allude to family history of disease as a risk factor. Before characterization of the human genome, heritability studies combined with family-based linkage studies supported the definition of AD as a complex trait in that interactions between genes and environmental factors and the interplay between multiple genes contribute to disease manifestation. A summary of more than 100 published reports on genetic association studies through mid-2009 implicates 81 genes, in 46 of which at least 1 positive association with AD has been demonstrated. Of these, the gene encoding filaggrin (FLG) has been most consistently replicated. Most candidate gene studies to date have focused on adaptive and innate immune response genes, but there is increasing interest in skin barrier dysfunction genes. This review examines the methods that have been used to identify susceptibility genes for AD and how the underlying pathology of this disease has been used to select candidate genes. Current challenges and the potential effect of new technologies are discussed.

CCL5/RANTES chemokine gene promoter polymorphisms are not associated with atopic and nonatopic asthma in a Spanish population

CCL5/RANTES, a member of the C-C chemokine family, is a potent eosinophil, monocyte, basophile and lymphocyte chemo-attractant at the site of inflammation. Recent studies revealed that a functional mutation at the -403 position in the promoter may have significance for atopic dermatitis, bronchial asthma, sarcoidosis, rheumatoid arthritis and HIV infection, and others. Another polymorphism in the -28 position has been reported. Our objective was to investigate the possible influence of the CCL5/RANTES promoter polymorphisms in the different types of bronchial asthma. CCL5/RANTES genotyping was performed by polymerase chain reaction-restriction fragment-length polymorphism (PCR-RFLP) in 306 asthmatic patients with non-atopic (n = 145) and atopic (n = 161) asthma and 242 controls. The 81.9% of the atopic asthma patients for -403G/A had the G allele and the A allele frequency was 18%. Of the non-atopic asthma patients, the G allele frequency was 79.7% and the A allele was 20.3%. Concerning the -28C/G polymorphism, the frequency of the CCL5/RANTES -28G allele in our patients is 2.8%, which is similar to Spanish adult population. After comparing patients with asthma, atopic patients, non-atopic patients and control population, we found no significant deviation in the distribution of the alleles or genotypes of CCL5/RANTES promoter polymorphisms in any tested comparison. Therefore, human CCL5/RANTES gene promoter polymorphisms are not associated with the different types of bronchial asthma in Spanish population.

The genetics of atopic dermatitis

BACKGROUND

Atopic dermatitis (AD) is a complex genetic disorder influenced by environmental factors. The mode of inheritance and genes involved are not clear.

RESULTS

This report here is focusing on the current progress in searching the disease-susceptibility genes of AD via both the linkage studies and candidate gene approaches. Genome-wide linkage studies have identified multiple susceptibility loci on 3q and 17q. Candidate region linkage studies identify other susceptibility loci on 5q23-33, 11q13, and 13q12-14. At least 28 candidate genes have to date been verified in association studies, but only association with genes of interleukin (IL)-4, IL-13, IL-4RA, mast cell chymase, and serine protease inhibitor, kazal-type 5 have been replicated in more than two different studies. More halpotype tests and family-based association studies may help to shed more light for the candidate gene approach.

CONCLUSION

Determining the candidate susceptibility genes for AD is not only helping understanding the pathophysiology but also affecting the response to therapy, which is important in pharmacogenetics. The effect of environmental trigger may also have to be considered to elucidate the real face of the disease.

Genetic susceptibility to atopic dermatitis

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

Association between the -2518G/A polymorphism in the monocyte chemoattractant protein-1 (MCP-1) gene and myocardial infarction in Tunisian patients

BACKGROUND

Monocyte chemoattractant protein-1 (MCP-1; gene name CCL2) has been suggested to play an important role in the initiation of atherosclerosis by recruiting monocytes to sites of injured endothelium. Recently, single nucleotide polymorphisms (SNPs) in the MCP-1 regulatory region have been identified. Controversial results regarding the association of the -2518G/A polymorphism of the MCP-1 gene with coronary artery disease (CAD) have been reported. In the present study, we examined a possible association between the -2518G/A polymorphism of the MCP-1 gene and myocardial infarction (MI) in a sample of the Tunisian population.

METHODS

A total of 319 Tunisian patients with MI and 467 healthy controls were included in the study. The SNP of the MCP-1 gene was determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis.

RESULTS

Patients with MI had significantly higher frequency of the AG+GG genotypes compared to controls [42.9% vs. 35.8%; OR (95%CI), 1.34 (1.00-1.79); p=0.04]. The MI patient group showed a significant higher frequency of the G allele compared to the controls [0.242 vs. 0.195; OR (95%CI), 1.31(1.02-1.68), p=0.03]. The association between the -2518G/A polymorphism of the MCP-1 gene and MI was no longer significant after adjustment for other well-established risk factors.

CONCLUSION

The present study showed a significant but not independent association between the -2518G/A polymorphism of the MCP-1 gene (presence of G allele) and MI in the Tunisian population.

Upregulating promoter polymorphisms of RANTES relate to atopic dermatitis

It has been reported that a functional polymorphism in the promoter of the RANTES gene (-403G/A) is associated with atopic dermatitis in a German population. Although there are several reports on the association of RANTES promoter polymorphisms (-403G/A and -28C/G) with asthma, the association of these polymorphisms with atopic dermatitis has not yet been confirmed in other populations. We therefore aimed to test whether the RANTES promoter polymorphisms relate to atopic dermatitis in a well-defined Japanese population. We conducted an association study of upregulating promoter polymorphisms of RANTES (-403G/A and -28C/G) in 389 patients with atopic dermatitis and 177 healthy control subjects. There was a significant association between the upregulating variant of RANTES -28G and atopic dermatitis, while -403A variant showed a significant association with atopic dermatitis with high IgE productivity. These results support a role for RANTES promoter polymorphisms in susceptibility to atopic dermatitis.

Polymorphisms in CCL2&CCL5 chemokines/chemokine receptors genes and their association with diseases

BACKGROUND

Chemokines and chemokine receptors are major mediators of leukocyte trafficking into the sites of the immune response. They participate in defence against microbial infection, in Th1/Th2 polarization of the immune response, allograft rejection and angiogenesis/angiostasis as well as in tumorigenesis and metastasis. To date, several functional polymorphisms of chemokine and chemokine receptor genes have been discovered that are able to deregulate chemokine system and, therefore, they may interfere with the pathogenesis of a large number of inflammatory and other diseases. In this review we focus on the known polymorphisms of two chemokines: CCL2, CCL5 and their corresponding receptors (CCR2, CCR5) and we also discuss their associations with susceptibility and progression to selected immune-mediated diseases.

METHODS AND RESULTS

Based on relevant literature this article gives a short overview of case-control and family studies regarding effect of the genetic factors on diseases such as coronary artery disease, systemic lupus erythematosus, diabetes mellitus, lung diseases and others.

CONCLUSION

Recent advance in the identification of chemokine genetic background of the diseases could provide opportunity for pharmacological treatment. However, we need more information about posttranscriptional events to understand functional relevance of polymorphisms and to discovery new avenues to blocking disease development.

Genetic variants of RANTES are associated with serum RANTES level and protection for type 1 diabetes

RANTES (regulated on activation, normal T-cell expressed and secreted) is a T-helper type 1 (Th1) chemokine that promotes T-cell activation and proliferation. RANTES is genetically associated with asthma, sarcoidosis and multiple sclerosis. The concentration of RANTES is increased at inflammation sites in different autoimmune diseases. Type 1 diabetes (T1D) is a Th1-mediated disease with complex genetic predisposition. We tested RANTES as a candidate gene for association with T1D using three single-nucleotide polymorphism (SNP) variants (rs4251719, rs2306630 and rs2107538) to capture haplotype information. The minor alleles of all SNPs were transmitted less frequently to T1D offspring (transmission rates 37.3% (P=0.002), 38.7% (P=0.007) and 41.0% (P=0.01)) and were less frequently present in patients compared to controls (P=0.009, 0.03 and 0.04, respectively). A similar protective effect was observed for the haplotype carrying three minor alleles (transmission disequilibrium test (TDT): P=0.003; odds ratio (OR)=0.55; confidence interval (CI): 0.37-0.83; case/control: P=0.03; OR=0.74; CI: 0.55-0.98). Both patients and controls carrying the protective haplotype express significantly lower serum levels of RANTES compared to non-carriers. Subsequently, we tested a cohort of 310 celiac disease patients, but failed to detect association. RANTES SNPs are significantly associated with RANTES serum concentration and development of T1D. The rs4251719*A-rs2306630*A-rs2107538*A haplotype associated with low RANTES production confers protection from T1D. Our data imply that RANTES is associated with T1D both genetically and functionally, and contributes to diabetes-prone Th1 cytokine profile.

Lack of association between the -403G/A promoter polymorphism in the human CCL5/RANTES chemokine gene in liver transplant outcome

Chemokines play a major role in the inflammatory and immune responses that mediate allograft outcome. CCL5/RANTES expansion chemokine is potent eosinophil, monocyte, basophils and lymphocyte chemoattractant and has recently been studied in transplantation with discrepant results, but systemic concentrations have been correlated to liver graft survival and incidence of rejection. Recent studies revealed that a functional mutation at -403 in the promoter may have a significance for inflammatory and infectious immune responses. Our objective was to investigate CCL5/RANTES promoter polymorphism in rejection and graft survival in liver transplant. We examined the CCL5/RANTES polymorphism in a series of 218 liver transplants and 101 healthy Caucasian subjects. CCL5/RANTES genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). After comparing recipients (with acute rejection episodes versus without rejection) with the control population, we found no significant deviation in the distribution of the alleles or genotypes of CCL5/RANTES dimorphism in any comparison (P > 0.05). Indeed, 5 years allograft survival was 61.3% in recipients with the GG genotype against 58.8% in recipients with the GA and AA genotypes. These differences were also not statistically significant. In conclusion, human CCL5/RANTES gene promoter polymorphism does not seem to influence acute rejection development and allograft survival in liver recipients.

The genetics of atopic dermatitis: recent findings and future options

Atopic dermatitis (AD) is a chronic pruritic skin disease affecting up to 15% of children in industrialized countries. AD belongs to the group of allergic disorders that include food allergy, allergic rhinitis, and asthma. A multifactorial background for AD has been suggested, with genetic as well as environmental factors influencing disease development. Genome-wide screens for AD have been completed in four different populations to date. Interestingly, the susceptibility regions identified for AD show little overlap with asthma susceptibility regions, suggesting that, at least in part, separate genes might be involved in the pathogenesis of the different atopic disorders. Instead, some of the identified regions overlap with susceptibility regions for psoriasis, another chronic skin disease. Thus, genes expressed in the skin might play an important role in AD pathogenesis, in addition to genes influencing atopic diatheses. Although no veritable "AD gene" has been identified by positional cloning to date, examples from other complex genetic disorders such as asthma show that this goal is likely to be reached in the near future. Candidate gene studies, on the other hand, have identified 19 genes that were shown to be associated with AD in at least one study. The results of genome-wide screens as well as candidate gene studies are evaluated here in detail.

HIV and the CCR5-Δ32 resistance allele

The combination of molecular biology, epidemiology, virology, evolutionary and population genetics has enabled us to understand the delicate interplay between HIV and the CCR5-Delta32 HIV resistance allele. We here review and collect from the different approaches to show how they can be combined to elucidate the interaction between host and pathogen genetics in this system. We will present an overview of the normal role of CCR5, its involvement in HIV, the molecular biology of the CCR5-Delta32 allele and its probable origins. By focusing on this well-documented and important system we hope to demonstrate the power that such a "holistic" approach might offer in the study of infectious diseases.

Chemokine RANTES promoter polymorphisms in allergic rhinitis

OBJECTIVES/HYPOTHESIS

RANTES is one of the most widely studied of the chemokines linked to allergic diseases. Two polymorphisms of the RANTES promoter region (-403 G/A and -28 C/G) have been found. The authors investigated whether these RANTES promoter polymorphisms were associated with allergic rhinitis.

STUDY DESIGN

Case-control study.

METHODS

Blood samples for genetic analysis were obtained from 151 individuals with allergic rhinitis and from 278 healthy individuals without atopic disease. Polymerase chain reaction-based assays for detection of the -403 G/A and -28 C/G polymorphisms of the RANTES gene were used for genotyping.

RESULTS

The frequencies of both the RANTES -403A and -28G alleles were significantly higher in patients with allergic rhinitis than in control subjects (P <.05 for both).

CONCLUSION

The study results indicated that the -403 and -28 alleles in the RANTES promoter region belong to the predictor gene set for allergic rhinitis and could be used in genomic analysis.

MCP-1 gene regulatory region polymorphism in Chinese children with mild, moderate and near-fatal asthma

BACKGROUND

A polymorphism in the monocyte chemoattractant protein 1 (MCP-1) gene regulatory region has been associated with asthma in Caucasians. This polymorphism is possibly endemic to the Asian region, but its impact on Asian populations is unclear. In addition, the relationship of this marker with life-threatening asthma has not been clarified. The aim of this study was to test the genetic association between the MCP-1 -2518A/G polymorphism and asthma/atopy in a cohort of Chinese children, with particular emphasis on those patients who had experienced life-threatening asthma attacks.

METHODS

Forty-eight children with near-fatal asthma, 134 mild-to-moderate asthmatics, 69 allergic-disorder cases without asthma, and 107 nonasthmatic, nonatopic control children were genotyped by a polymerase chain reaction-based assay.

RESULTS

Comparison of the four groups of children (n = 358) revealed no detectable differences in genotype or allele frequencies of the MCP-1 -2518A/G polymorphism. There was no evidence of association between the polymorphism and any of the outcomes of interest including clinical severity, blood eosinophil count, atopy, total serum IgE levels, and degree of bronchial hyper-responsiveness.

CONCLUSION

These results suggest that the MCP-1 -2518A/G polymorphism is not a risk factor for near-fatal asthma. Furthermore, this polymorphism seems to play no role in the development of asthma or atopy in Chinese subjects, possibly as a result of the genetic heterogeneity between Asian and Caucasian populations with respect to regulation of MCP-1 expression. Our results underscore the necessity of accounting for ethnic background in the investigation of asthma-predisposition genes.

Dermatite atopique : quels sont les critères diagnostiques utilisés dans les articles scientifiques ?

INTRODUCTION

Diagnosis of atopic dermatitis currently relies on diagnostic criteria scales developed by Hanifin and Rafka in 1980 and by the "United Kingdom Working party" in 1994. Some authors have proposed: "AEDS" [sM1] and "Atopiform Dermatitis", which has led to the distinction between different sub-populations and the exclusion of certain diseases from the diagnosis of atopic dermatitis. The aim of our study was to collect the criteria retained in the scientific medical literature during the year 2002 for the definition of atopic dermatitis and to try to understand not only the interest but also the questions that the various definitions lead to.

METHOD

A PubMed research was launched with the key word "atopic dermatitis" from January to September of 2002. All the scientific articles either in French or in English were studied.

RESULTS

Hanifin and Rafka's criteria were selected in 44 p. 100 of the scientific articles, and the "United Kingdom Working Party" criteria in 12 p. 100. Personal definitions were used in 21 p. 100 of the articles; these were based on the level of total and specific IgE or on personal clinical criteria. For twenty-three p. 100 of the authors, the definition of atopic dermatitis was not specified.

DISCUSSION

There was not just one definition of atopic dermatitis. This may affect the interpretation of diagnostic or therapeutic papers concerning the disease, because there has been no proof that these definitions cover the same population of patients.

Association studies for asthma and atopic diseases: a comprehensive review of the literature

Hundreds of genetic association studies on asthma-related phenotypes have been conducted in different populations. To date, variants in 64 genes have been reported to be associated with asthma or related traits in at least one study. Of these, 33 associations were replicated in a second study, 9 associations were not replicated either in a second study or a second sample in the same study, and 22 associations were reported in just a single published study. These results suggest the potential for a great amount of heterogeneity underlying asthma. However, many of these studies are methodologically limited and their interpretation hampered by small sample sizes.

The RANTES promoter polymorphism: a genetic risk factor for near-fatal asthma in Chinese children

BACKGROUND

RANTES promoter polymorphisms were found associated with asthma/atopy in some studies but not others, possibly reflecting the genetic heterogeneity among different ethnicities and different asthma severity.

OBJECTIVE

The purpose of this investigation was to test the genetic association between the RANTES -28C/G and -403G/A polymorphisms and asthma/atopy in a cohort of Chinese children, with particular emphasis on those patients who had experienced life-threatening asthma attacks.

METHODS

Forty-eight children with near-fatal asthma, 134 children with mild-to-moderate asthma, 69 children with allergic disorders but no asthma, and 107 nonasthmatic nonatopic control children were genotyped through use of a PCR-based assay.

RESULTS

No significant difference was demonstrated for frequency of the RANTES -28C/G polymorphism when the mild-to-moderate asthma, atopic/nonasthmatic, and normal control groups were compared. The RANTES -28G allele was present in a significantly higher proportion of the children with near-fatal asthma compared with the nonasthmatic nonatopic controls (odds ratio, 2.93 [1.41-6.06]; P =.006) and the children with mild-to-moderate asthma (odds ratio, 3.52 [1.73-7.16]; P =.001). The frequency of -28G allele carriage correlated with asthma severity. The RANTES -28G allele was also associated with an increased blood eosinophil count and a higher degree of bronchial hyperresponsiveness. The RANTES -403G/A polymorphism did not influence asthma/atopy susceptibility, blood eosinophil count, or bronchial hyperresponsiveness. Interestingly, a higher frequency of -403A allele carriage was observed in the moderate asthma subgroup compared with the mild asthma analog.

CONCLUSIONS

We conclude that the RANTES -28C/G polymorphism exacerbates asthma severity, representing a genetic risk factor for life-threatening asthma attacks in Chinese children. In addition, the linkage disequilibrium between these 2 polymorphisms is a potential confounder that must be considered in the design and interpretation of RANTES gene association studies.