Unusual haplotypic structure of IL8, a susceptibility locus for a common respiratory virus

Single nucleotide polymorphisms as susceptibility, prognostic, and therapeutic markers of nonsmall cell lung cancer

Lung cancer is a major public health problem throughout the world. Among the most frequent cancer types (prostate, breast, colorectal, stomach, lung), lung cancer is the leading cause of cancer-related deaths worldwide. Among the two major subtypes of small cell lung cancer and nonsmall cell lung cancer (NSCLC), 85% of tumors belong to the NSCLC histological types. Small cell lung cancer is associated with the shortest survival time. Although tobacco smoking has been recognized as the major risk factor for lung cancer, there is a great interindividual and interethnic difference in risk of developing lung cancer given exposure to similar environmental and lifestyle factors. This may indicate that in addition to chemical and environmental factors, genetic variations in the genome may contribute to risk modification. A common type of genetic variation in the genome, known as single nucleotide polymorphism, has been found to be associated with susceptibility to lung cancer. Interestingly, many of these polymorphisms are found in the genes that regulate major pathways of carcinogen metabolism (cytochrome P450 genes), detoxification (glutathione S-transferases), adduct removal (DNA repair genes), cell growth/apoptosis (TP53/MDM2), the immune system (cytokines/chemokines), and membrane receptors (nicotinic acetylcholine and dopaminergic receptors). Some of these polymorphisms have been shown to alter the level of mRNA, and protein structure and function. In addition to being susceptibility markers, several of these polymorphisms are emerging to be important for response to chemotherapy/radiotherapy and survival of patients. Therefore, it is hypothesized that single nucleotide polymorphisms will be valuable genetic markers in individual-based prognosis and therapy in future. Here we will review some of the most important single nucleotide polymorphisms in the metabolic pathways that may modulate susceptibility, prognosis, and therapy in NSCLC.

Impact of interleukin-8 gene polymorphisms and environmental factors on oral cancer susceptibility in Taiwan

OBJECTIVES

Interleukin-8 (IL-8), which is an angiogenic chemokine with a high expression level in tumor tissues, plays important roles in developing many human malignancies including oral squamous cell carcinoma (OSCC). This study was designed to examine the association of IL-8 gene polymorphisms with the susceptibility and clinicopathological characteristics of OSCC.

METHODS

A total of 270 patients with OSCC and 350 healthy control subjects were recruited. Four single nucleotide polymorphisms (SNPs) of IL-8 genes were analyzed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) genotyping analysis.

RESULTS

Results showed that four IL-8 SNPs (-251 T/A, +781 C/T, +1633 C/T, and +2767 A/T) were not associated with oral cancer susceptibility as well as clinicopathological parameters. But among 345 smokers, IL-8 polymorphisms carriers with betel quid chewing were found to have a 17.41- to 23.14-fold risk to have oral cancer compared to IL-8 wild-type carriers without betel quid chewing. Among 262 betel quid chewers, IL-8 polymorphisms carriers with smoking have a 10.54- to 20.44-fold risk to have oral cancer compared to those who carried wild type without smoking.

CONCLUSIONS

Our results suggest that the combination of IL-8 gene polymorphisms and environmental carcinogens might be highly related to the risk of oral cancer.

Genetic variation and clinical heterogeneity in cystic fibrosis

Cystic fibrosis (CF), a lethal genetic disease, is characterized by substantial clinical heterogeneity. Work over the past decade has established that much of the variation is genetically conferred, and recent studies have begun to identify chromosomal locations that identify specific genes as contributing to this variation. Transcriptomic and proteomic data, sampling hundreds and thousands of genes and their products, point to pathways that are altered in the cells and tissues of CF patients. Genetic studies have examined more than half a million polymorphic sites and have identified regions, and probably genes, that contribute to the clinical heterogeneity. The combination of these approaches has great potential because genetic profiling identifies putative disease-modifying processes, and transcript and protein profiling is shedding light on the biology involved. Such studies are providing new insights into the disease, such as altered apoptotic responses, oxidative stress dysregulation, and neuronal involvement, all of which may open new therapeutic avenues to exploration.

Evidence for a causal relationship between respiratory syncytial virus infection and asthma

Respiratory syncytial virus (RSV) infects all children early in life, is the most common cause of infant lower respiratory tract infections, and causes disease exacerbations in children with asthma. Episodes of lower respiratory tract infection in early life are associated with asthma development. Whether RSV infection early in life directly causes asthma or simply identifies infants who are genetically predisposed to develop subsequent wheezing is debatable. Recent studies suggest that these two explanations are not mutually exclusive, and are likely both important in asthma development. An open-label study of RSV immunoprophylaxis administered to preterm infants reduced recurrent wheezing by 50%. Clinical trials of infant RSV prevention, delay or severity reduction on the outcome of childhood asthma would confirm the causal relationship between RSV infection and asthma, and offer a primary prevention strategy.

Virus respiratorio sincitial, metapneumovirus y virus parainfluenza humanos: cuadro clínico y fisiopatología

El VRSh causa la mayor parte de las bronquiolitis del lactante, infecciones respiratorias bajas que provocan trastornos respiratorios obstructivos y sibilancias. Los factores relacionados con las características del paciente (prematuridad, enfermedades asociadas, predisposición genética), con el virus (VRShA, genotipo, etc.) o el ambiente (contaminación, tabaquismo, etc.) son determinantes en la génesis de las bronquiolitis y determinan su gravedad. La mortalidad de la bronquiolitis es del 0,005-0,2% dependiendo de las características del paciente. No se conoce la fisiopatología de la bronquiolitis por VRSh. El papel directo del virus sobre el epitelio, la inmadurez del pulmón del lactante y, como se ha demostrado recientemente, el papel de la reacción inflamatoria, son factores destacados. También es probable que haya mecanismos inmunopatológicos (anticuerpos IgE, respuesta CD4+ Th2, etc.) que intervengan en ciertas bronquiolitis. La inmunidad anti-VRSh nunca llega a ser completa y las reinfecciones son frecuentes en los niños pequeños y las personas de edad avanzada, en quienes la infección por el VRSh representa aproximadamente el 5% de las afecciones respiratorias bajas. Con frecuencia se presentan con un cuadro de neumopatía infecciosa atípica con signos de bronquiolitis. Las infecciones debidas al VPIh3 suelen manifestarse por bronquiolitis, y las infecciones secundarias al VPIh1 y al 2 por laringotraqueítis. No se conoce bien la expresión clínica de las infecciones por VPIh4. El MPVh causa bronquiolitis comparables en todos sus aspectos a las que origina el VRSh.

Relationship of interleukin-8 gene polymorphisms with hepatocellular carcinoma susceptibility and pathological development

BACKGROUND AND OBJECTIVES

Hepatocellular carcinoma (HCC) is one of the most frequent malignant neoplasms worldwide, and the second leading cause of death from cancer in Taiwan. Interleukin-8 (IL-8) is an angiogenic chemokine with important roles in the development and progression of many human malignancies including HCC. This study investigates the effects of single-nucleotide polymorphisms (SNPs) in the IL-8 gene on the susceptibility and clinicopathological characteristics of HCC.

METHODS

One hundred thirty-one HCC patients and 340 control subjects were analyzed for four IL-8 SNPs (-251 T/A, +781 C/T, +1633 C/T, and +2767 A/T) using PCR-RFLP genotyping analysis.

RESULTS

After adjusting for other confounders, results show that individuals with the IL-8 +781 T/T polymorphic genotype had a significantly lower risk of developing HCC than those with the wild-type (C/C) genotype (AOR = 0.346; 95% CI: 0.132-0.909). Multiple regression analysis showed that the presence of T/A or A/A at IL-8 -251 may indicate higher potential risk of hepatitis B infection (AOR = 2.847; 95% CI: 1.083-8.656). Additionally, these four IL-8 SNPs did not associate with liver-related clinicopathological markers in serum.

CONCLUSIONS

Genetic polymorphism at IL-8 +781 is an important factor in determining susceptibility to HCC in the Taiwanese population.

Variation in European harbour seal immune response genes and susceptibility to phocine distemper virus (PDV)

Phocine distemper virus (PDV) has caused two mass mortalities of European harbour seals (Phoca vitulina) in recent decades. Levels of mortality varied considerably among European populations in both the 1988 and 2002 epidemics, with higher mortality in continental European populations in comparison to UK populations. High levels of genetic differentiation at neutral makers among seal populations allow for the possibility that there could be potential genetic differences at functional loci that may account for some of the variation in mortality. Recent genome sequencing of carnivore species and development of genomic tools have now made it possible to explore the possible contribution of variation in candidate genes from harbour seals in relation to the differential mortality patterns. We assessed variation in eight genes (CD46, IFNG, IL4, IL8, IL10, RARa, SLAM and TLR2) encoding key proteins involved in host cellular interactions with Morbilliviruses and the relationship of variants to disease status. This work constitutes the first genetic association study for Morbillivirus disease susceptibility in a non-model organism, and for a natural mortality event. We found no variation in harbour seals from across Europe in the protein coding domains of the viral receptors SLAM and CD46, but SNPs were present in SLAM intron 2. SNPs were also present in IL8 p2 and RARa exon 1. There was no significant association of SLAM or RARa polymorphisms with disease status implying no role of these genes in determining resistance to PDV induced mortality, that could be detected with the available samples and the small number of polymorphisms indentified. However there was significant differentiation of allele frequencies among populations. PDV and other morbilliviruses are important models for wildlife epidemiology, host switches and viral evolution. Despite a negative result in this case, full sequencing of pinniped and other 'non-model' carnivore genomes will help in refining understanding the role of host genetics in disease susceptibility for these viruses.

-251 T/A polymorphism of the interleukin-8 gene and cancer risk: a HuGE review and meta-analysis based on 42 case-control studies

The -251T/A (rs4073), a single nucleotide polymorphism, has been identified in the promoter region of the interleukin-8 (IL-8) gene. It's presence could influence the production of IL-8 protein by regulating the transcriptional activity of the gene. A large number of studies have been performed to evaluate the role of -251T/A polymorphism on various cancers, with inconsistent results being reported. In this paper, we summarized 13,189 cases and 16,828 controls from 42 case-control studies and attempted to assess the susceptibility of -251T/A polymorphism to cancers by a comprehensive meta-analysis. Pooled odds ratios and 95% confidence intervals were calculated by using the random-effects model. Publication bias, subgroup, and sensitivity analysis were also performed. Results showed that the carriers of the -251A allele had about a 12-21% increased risk for the reviewed cancer, in total. The carriers of -251A had an elevated risk to breast cancer, gastric cancer and nasopharyngeal cancer and a reduced risk to prostate cancer, but no evidence was found to indicate that the -251A allele predisposed its carriers to colorectal and lung cancers. When stratified separately by 'racial descent' and 'study design', it was found that the carriers of the -251A allele among the African group, Asian group and hospital-based case-control study group were at a higher risk for cancer, but not in European group and population-based case-control study. These results show that -251A allele is susceptible in the development of low-penetrance cancers.

Genetic polymorphisms and susceptibility to parenchymal renal infection among pediatric patients

BACKGROUND

Patient susceptibility to bacterial urinary tract infections, which is determined by complex pathogen-host interactions, varies between individuals due to genetic variation. The neutrophil-dependent innate immune system is an important part of keeping the urinary tract sterile. This study was performed to explore single nucleotide polymorphisms (SNPs) in genes associated with neutrophil-dependent immunity in pediatric patients with severe parenchymal infections.

METHODS

The subjects included patients who fulfilled the diagnostic criteria of acute pyelonephritis (APN) and acute lobar nephronia (ALN) without underlying disease or structural anomalies (excluding vesicoureteral reflux). Genotyping of the genes encoding toll-like receptor 4 (TLR-4), interleukin-8 (IL-8), and IL-8 receptors CXCR1 and CXCR2 was performed by matrix-assisted laser desorption/ionization time-of-flight-based mini-sequencing analysis.

RESULTS

A total of 17 SNPs, including missense SNPs and those located in promoter regions, were initially selected for genotyping. Only 4 SNPs with a heterozygosity rate >0.01 were evaluated further. The observed genotype frequencies satisfied Hardy-Weinberg equilibrium. Statistical analysis revealed that only IL-8 (rs4073, -251A>T) showed significant differences in genotype and allele frequency between the control and APN or ALN cases. Following the elimination of vesicoureteral reflux, which is a significant risk factor for severe parenchymal infection, a single SNP in IL-8 (rs4073) was found to be associated with clinically severe ALN.

CONCLUSIONS

The AA genotype and A allele of the IL-8 SNP is related to patient susceptibility to parenchymal infection and is correlated with the severity of infection in pediatric APN and ALN patients, probably due to the upregulation of IL-8 expression.

Polymorphisms in genes controlling inflammation and tissue repair in rheumatoid arthritis: a case control study

Background

Various cytokines and inflammatory mediators are known to be involved in the pathogenesis of rheumatoid arthritis (RA). We hypothesized that polymorphisms in selected inflammatory response and tissue repair genes contribute to the susceptibility to and severity of RA.

Methods

Polymorphisms in TNFA, IL1B, IL4, IL6, IL8, IL10, PAI1, NOS2a, C1INH, PARP, TLR2 and TLR4 were genotyped in 376 Caucasian RA patients and 463 healthy Caucasian controls using single base extension. Genotype distributions in patients were compared with those in controls. In addition, the association of polymorphisms with the need for anti-TNF-α treatment as a marker of RA severity was assessed.

Results

The IL8 781 CC genotype was associated with early onset of disease. The TNFA -238 G/A polymorphism was differentially distributed between RA patients and controls, but only when not corrected for age and gender. None of the polymorphisms was associated with disease severity.

Conclusions

We here report an association between IL8 781 C/T polymorphism and age of onset of RA. Our findings indicate that there might be a role for variations in genes involved in the immune response and in tissue repair in RA pathogenesis. Nevertheless, additional larger genomic and functional studies are required to further define their role in RA.

Haplotypes in the interleukin 8 gene and their association with chronic periodontitis susceptibility

Interleukin-8 (IL-8), which is responsible for the migration and activation of neutrophils, is an important inflammatory mediator involved in the initiation and amplification of acute inflammatory reactions and chronic inflammatory processes. IL-8 plays an important role in periodontitis, an inflammatory disease characterized by the loss of connective tissue and alveolar bone. The aim of this study was to investigate whether the SNPs rs2227307 (+396) and rs2227306 (+781), and the haplotypes they formed together with the previously investigated rs4073 (-251), were associated with chronic periodontitis susceptibility. Clinical periodontal exams were performed and DNA samples were collected from 493 individuals (223 with periodontitis and 270 controls). Associations between SNPs, haplotypes, and subject phenotypes were analyzed using the χ(2) test followed by multivariate logistic regression modeling. We conclude that the +396TT genotype and the haplotypes ATC/TTC and AGT/TGC were significantly associated with chronic periodontitis susceptibility in Brazilians.

Interleukin-8 gene promoter polymorphism (rs4073) may contribute to chronic periodontitis

BACKGROUND

The proinflammatory chemokine interleukin (IL)-8 is important in the regulation of the inflammatory response. Analyses of the single nucleotide polymorphism (SNP) reference sequence (rs) 4073 showed that the A allele upregulated IL-8 levels after stimulation with lipopolysaccharides. We investigated the association of the SNP rs4073 with chronic periodontitis.

METHODS

Genotyping was performed by a standard polymerase chain reaction-restriction fragment length polymorphism assay in 289 genomic DNA samples of healthy control subjects and patients with chronic periodontitis; analyses were adjusted by multivariate logistic regression modeling. A real-time polymerase chain reaction performance was used to detect levels of the IL-8 mRNA.

RESULTS

The analysis pointed to a statistically significant association of chronic periodontitis with the heterozygous TA genotype (P = 0.001); the results showed an increase in the frequency of the A allele in the diseased group (36% in the control group versus 48% in the periodontitis group). The higher levels of the IL-8 mRNA were found in the periodontitis group, mainly in individuals who presented the TA genotype (P = 0.03).

CONCLUSION

The SNP rs4073 was associated with chronic periodontitis in non-smoker Brazilian subjects because the frequency of the A allele was higher in the disease group than in the control group, and the TA genotype was associated with increased levels of IL-8 mRNA transcripts.

Acute resistance exercise results in catecholaminergic rather than hypothalamic-pituitary-adrenal axis stimulation during exercise in young men

Exercise is a paradigm of a stress situation. The adaptive response to stressors comprises the activation of the hypothalamic-pituitary-adrenal (HPA) axis and components of the autonomic sympathetic system. An aseptic inflammatory reaction is triggered by exercise, involving the stimulation of the so-called proinflammatory cytokines, such as tumor necrosis factor α (TNFα), interleukin-1 (IL-1), and IL-6. The anti-inflammatory cytokines IL-2, IL-8, and IL-10 increase moderately during resistance exercise. To investigate the effect of a short bout of resistance exercise on components of the stress and inflammatory responses during the exercise period, 17 healthy, young, untrained male volunteers were studied during 3 equal consecutive cycles of resistance exercises of 30 min total duration. Blood sampling was performed at baseline and at the end of each cycle. Lactate, cortisol, catecholamines (epinephrine, norepinephrine), IL-1α, IL-1β, IL-2, IL-6, IL-8, IL-10, epidermal growth factor (EGF), and monocyte chemotactic protein-1 (MCP-1) were measured at all time-points. Circulating levels of catecholamines and lactate increased significantly (P < 0.05) whereas cortisol did not. During the time course of the exercise, circulating levels of TNFα, IL-2, and EGF increased, whereas MCP-1 decreased significantly. IL-1α, IL-1β, IL-6, IL-8, and IL-10 levels did not change significantly. Statistically significant positive linear correlations were found between areas under the curve for increases in levels of IL-2 and TNFα, TNFα and cortisol, as well as epinephrine and norepinephrine. We conclude that acute resistance exercise results in catecholaminergic, but not HPA axis stimulation during exercise, in parallel with a mild inflammatory reaction. The absence of a major inflammatory reaction and of a cortisol increase during acute resistance exercise makes this a good candidate for the exercise of sedentary individuals.

Genetic associations with asthma and virus-induced wheezing: a systematic review

Various wheezing phenotypes can be identified based on differences in natural histories, risk factors and responses to treatment. In epidemiologic studies, atopic asthma or virus-induced wheezing can be discriminated by the presence or the absence of sensitization to allergens. Children with asthma have been shown to present lower levels of lung function. Patients with viral respiratory infections evolve from normal lung function to enhanced airway reactivity. The objective of this study was to identify genes and polymorphisms associated with different wheezing phenotypes. Using data obtained from the Genetic Association Database, we systematically reviewed studies on genes and polymorphisms that have been associated with virus-induced wheezing or atopic asthma. The research was carried out in February of 2009. Genes associated with the studied outcomes in more than three studies were included in the analysis. We found that different genes and loci have been associated with virus-induced wheezing or atopic asthma. Virus-induced wheezing has frequently been associated with IL-8 polymorphisms, whereas atopic asthma and atopy have frequently been associated with Th2 cytokine gene (CD14 and IL-13) polymorphisms on chromosome 5. This review provides evidence that different wheezing disorders in childhood can be differently affected by genetic variations, considering their role on airway inflammation and atopy. Future studies of genetic associations should consider the different wheezing phenotypes in infancy. In addition, stratified analyses for atopy can be useful for elucidating the mechanisms of the disease.

Association of haplotypes in the IL8 gene with susceptibility to chronic periodontitis in a Brazilian population

BACKGROUND

Interleukin 8 (IL-8) is a chemokine related to the initiation and amplification of acute and chronic inflammatory processes. Polymorphisms in the IL8 gene have been associated with inflammatory diseases. We investigated whether the -845(T/C) and -738(T/A) single nucleotide polymorphisms (SNPs) in the IL8 gene, as well as the haplotypes they form together with the previously investigated -353(A/T), are associated with susceptibility to chronic periodontitis.

METHODS

DNA was extracted from buccal epithelial cells of 400 Brazilian individuals (control n=182, periodontitis n=218). SNPs were genotyped by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Disease associations were analyzed by the chi(2) test, Exact Fisher test and Clump program. Haplotypes were reconstructed using the expectation-maximization algorithm and differences in haplotype distribution between the groups were analyzed to estimate genetic susceptibility for chronic periodontitis development.

RESULTS

When analyzed individually, no SNPs showed different distributions between the control and chronic periodontitis groups. Although, nonsmokers carrying the TTA/CAT (OR=2.35, 95% CI=1.03-5.36) and TAT/CTA (OR=6.05, 95% CI=1.32-27.7) haplotypes were genetically susceptible to chronic periodontitis. The TTT/TAA haplotype was associated with protection against the development of periodontitis (for nonsmokers OR=0.22, 95% CI=0.10-0.46).

CONCLUSION

Although none of the investigated SNPs in the IL8 gene was individually associated with periodontitis, some haplotypes showed significant association with susceptibility to, or protection against, chronic periodontitis in a Brazilian population.

Genetic traits for the persistence of Helicobacter pylori infection

Helicobacter pylori infection elevates the risk of gastric diseases, including peptic ulcer and gastric cancer. Persistent infection is the first step to induce H. pylori-induced multistage diseases. Although the roles of genetic traits on persistent infection have not yet been elucidated, some individuals escape from persistent infection. Possible favorable conditions for H. pylori seem to be low acid secretion, reduced innate immune responses, and easier binding to gastric epithelial cells. IL-1β and TNF-α inhibit acid secretion. The genetic polymorphisms associated with both molecules have the potential to be the genetic traits underlying persistent infection. Functional polymorphisms associated with innate immune responses could also be involved with the genetic traits, but no polymorphisms with consistent associations have been identified so far. The polymorphisms associated with molecules for adhesion to epithelial cells are candidates of genetic traits, but more research is needed.

IL-8 -251A/T polymorphism is associated with decreased cancer risk among population-based studies: evidence from a meta-analysis

Growing evidence suggests that interleukin-8 (IL-8) play pivotal roles in the pathogenesis of cancer through the modulation of tumour immune response or enhanced angiogenesis. A single nucleotide polymorphism, -251A/T, has been identified in the promoter region of the IL-8 gene and has been shown to influence its production. Results from previous studies on the association of -251A/T polymorphism with different cancer types remained contradictory. To assess the effect of -251A/T of IL-8 on cancer susceptibility, we conducted a meta-analysis, up to May 2009, of 14,876 cases with different cancer types and 18,465 controls from 45 published case-control studies. Summary odds ratios and corresponding 95% confidence intervals (CIs) for IL-8 polymorphism and cancer were estimated using fixed- and random-effects models when appropriate. The AA/AT genotypes were associated with a significantly increased risk of nasopharyngeal carcinoma when compared with TT genotype (OR=1.48; 95% CI, 1.16-1.89). Moreover, significantly elevated risks were observed in 'other cancers', and also in African population when population is concerned. Interestingly, when stratified separately by population-based studies and hospital-based studies, significantly elevated risk was found among hospital-based studies (OR=1.21, 95% CI, 1.07-1.37), whereas significantly decreased risk was found among population-based studies (OR=0.90, 95% CI, 0.83-0.97). This meta-analysis shows that IL-8 -251A/T polymorphism may play a complex role in cancer development.

Innate immunity in ocular Chlamydia trachomatis infection: contribution of IL8 and CSF2 gene variants to risk of trachomatous scarring in Gambians

BACKGROUND

Trachoma, a chronic keratoconjunctivitis caused by Chlamydia trachomatis, is the world's commonest infectious cause of blindness. Blindness is due to progressive scarring of the conjunctiva (trachomatous scarring) leading to in-turning of eyelashes (trichiasis) and corneal opacification. We evaluated the contribution of genetic variation across the chemokine and cytokine clusters in chromosomes 4q and 5q31 respectively to risk of scarring trachoma and trichiasis in a large case-control association study in a Gambian population.

METHODS

Linkage disequilibrium (LD) mapping was used to investigate risk effects across the 4q and 5q31 cytokine clusters in relation to the risk of scarring sequelae of ocular Ct infection. Disease association and epistatic effects were assessed in a population based study of 651 case-control pairs by conditional logistic regression (CLR) analyses.

RESULTS

LD mapping suggested that genetic effects on risk within these regions mapped to the pro-inflammatory innate immune genes interleukin 8 (IL8) and granulocyte-macrophage colony stimulatory factor (CSF2) loci. The IL8-251 rare allele (IL8-251 TT) was associated with protection from scarring trachoma (OR = 0.29 p = 0.027). The intronic CSF2_27348 A allele in chromosome 5q31 was associated with dose dependent protection from trichiasis, with each copy of the allele reducing risk by 37% (p = 0.005). There was evidence of epistasis, with effects at IL8 and CSF2 loci interacting with those previously reported at the MMP9 locus, a gene acting downstream to IL8 and CSF2 in the inflammatory cascade.

CONCLUSION

innate immune response SNP-haplotypes are linked to ocular Ct sequelae. This work illustrates the first example of epistatic effects of two genes on trachoma.

Interleukin-8 T-251A polymorphism was associated with positive anti-p53 antibodies in Uzbekistan population

Interleukin (IL)-8, a proinflammatory chemokine, has been reported to have angiogenic activity and to be responsible for tumor-associated angiogenesis in several cancers. The polymorphism IL-8 T-251A (rs4073) is known to be associated with the expression of IL-8 protein and is related to several cancers. A serum anti-p53 antibody, a new tumor marker, increases in accordance with the mutation of tumor suppressor gene p53. Previous studies have reported the association between IL-8 and p53 mutation in cancer cells or tissues. Therefore, we hypothesized that IL-8 polymorphism might be associated with serum anti-p53 antibody levels. Study subjects were 197 participants (103 males and 94 females, aged 15 to 56 years) who were enrolled in a case-control study on peptic ulcer disease from January to March 2007 in the Uzbekistan Republic. Serum anti-p53 antibody, CEA, and CA19-9 levels were measured, and IL-8 T-251A was genotyped. The A allele frequency in control subjects was 0.48, which is close to the previous reports for Caucasian populations. The proportion of subjects with positive anti-p53 antibodies (higher than 1.3 U/ mL) was greater for AA genotype carriers compared to T allele carriers (17% for AA, and 6% for TA+TT; OR 3.4, p = 0.025 after adjusting for age, sex, comorbidity and ethnicity). Such a difference was not observed for either CEA or CA19-9. We demonstrated that the IL-8 -251 AA genotype was associated with higher anti-p53 antibodies than those of the reference range. Further studies are warranted to clarify whether those with this genotype carrier are susceptible to malignant diseases.

Genetic diversity of the host and severe respiratory syncytial virus-induced lower respiratory tract infection

Respiratory syncytial virus (RSV)-induced lower respiratory tract disease is a common problem in children and adults in Western societies. The clinical range of RSV infection from asymptomatic to respiratory distress syndrome is believed to be the outcome of viral and host immunity interactions. Genes associated with immune response are of particular interest regarding genetic predisposition to severe RSV infection. Several investigators have sought to identify genetic markers for high-risk patients, and more than 20 independent studies in the medical literature assess the impact of genetic variations-mostly single nucleotide polymorphisms-on the clinical presentation of RSV-induced disease. Several candidate gene loci have been tested in association studies based on the concept that a particular allele is a significant risk factor for a phenotype of interest. Despite the wealth of information available, we are still far from evolving a practical and cost-effective screening tool; certain flaws in association studies first need to be overcome. The development of haplotype-based analysis for candidate loci across the genome, along with advances in biostatistics and bioinformatics, would facilitate the assessment of the relative contribution of genetic markers to disease susceptibility in RSV infection.

Genetic variations in inflammatory mediators influence lung disease progression in cystic fibrosis

The clinical course of cystic fibrosis (CF) varies considerably among patients carrying the same CF-causing gene mutation. Additional genetic modifiers may contribute to this variability. As airway inflammation is a key component of CF pathophysiology, we investigated whether major cytokine variants represent such modifiers in young CF patients. We tested 13 polymorphisms in 8 genes that play a key role in the inflammatory response: tumor necrosis factor, lymphotoxin alpha, interleukin (IL) 1B, IL1 receptor antagonist, IL6, IL8, IL10 and transforming growth factor beta 1 (TGFB1), for an association with lung disease progression and nutritional status in 329 CF patients. Variants in the TGFB1 gene at position +869T/C demonstrated a significant association with lung function decline. A less pronounced rate of decline in forced expiratory volume in 1 sec (FEV(1)) and forced vital capacity (FVC) were observed in patients heterozygous for TGFB1 +869 (+869CT), when compared to patients carrying either TGFB1 +869TT or +869CC genotypes. These findings support the concept that TGFB1 gene variants appear to be important genetic modifiers of lung disease progression in CF.

Cigarette smoke condensate enhances respiratory syncytial virus-induced chemokine release by modulating NF-kappa B and interferon regulatory factor activation

Exposure to cigarette smoke is a risk factor contributing to the severity of respiratory tract infections associated with respiratory syncytial virus (RSV). Stimulation of airway epithelial cells by either RSV or cigarette smoke condensate (CSC) has been shown to induce secretion of the proinflammatory chemokines. However, the effect of coexposure of airway epithelial cells to CSC and RSV on inducible chemokine production has not been previously investigated. The results of this study indicate that CSC costimulation significantly increased RSV-induced interleukin-8 (IL-8) and monocyte chemoattactant protein-1 gene and protein expression when compared with each stimulus alone. Promoter deletion studies identified the interferon stimulatory response element (ISRE) of the IL-8 promoter as a critical region responsible for the synergistic increase of IL-8 gene transcription during mixed exposure. CSC costimulation enhanced RSV-induced activation of interferon regulatory factor (IRF)-1 and IRF-7, which bind to the ISRE site. CSC also furthered RSV-induced activation of the transcription factor nuclear factor kappa B (NF-kappaB), as shown by increased NF-kappaB DNA binding to its specific site of the IL-8 promoter and increased NF-kappaB-driven gene transcription. Therefore, our data demonstrate that a combined exposure to CSC and RSV synergistically increases chemokine expression in airway epithelial cells, suggesting that CSC contributes to an exuberant immune response to RSV by stimulating overlapping signal transduction pathways.

Cytokine and cytokine receptor gene polymorphisms and their functionality

Cytokines, signaling proteins produced by a variety of cell types, are essential for the development and functioning of both innate and adaptive immune response. Cytokine gene expression is tightly regulated, and aberrant expression from environmental and genetic polymorphism has been implicated in a range of diseases, susceptibility to infections, and responses to treatment. This review concentrates on the functionality of cytokine and cytokine receptor gene polymorphisms; it is through these variants that genuine disease-associations are based. Several mechanisms for single nucleotide polymorphism (SNP) functionality are present within cytokine genes including: amino acid changes (IL-6R, IL-13, IL-1alpha), exon skipping (IL-7Ralpha), proximal promoter variants (IL-1beta, IL-Ra, IL-2, IL-6, IL-10, IL-12, IL-13, IL-16, TNF, IFN-gamma, TGF-beta), distal promoter variants (IL-6, IL-18) and intronic enhancer variants (IL-8).

Modulation of cystic fibrosis lung disease by variants in interleukin-8

Cystic fibrosis pulmonary disease is characterized by excessive and prolonged inflammation. CF Pulmonary disease severity exhibits considerable variation that, to some extent, appears to be due to the presence of modifier genes. Several components of the inflammatory response are known to have altered regulation in the CF lung. Genetic variants in 52 inflammatory genes were tested for associations with lung disease indices in a CF patient population (n=737) homozygous for the DeltaF508 cystic fibrosis transmembrane conductance regulator mutation. Variants in three inflammatory genes showed significant genotypic associations with CF lung disease severity, including IL8 and previously reported TGFbeta1 (P< or =0.05). When analyzed by gender, it was apparent that IL8 variant associations were predominantly due to males. The IL8 variants were tested in an additional CF population (n=385) and the association in males verified (P< or =0.01). The IL8 variants were in strong linkage disequilibrium with each other (R2> or =0.82), while variants in neighboring genes CXCL6, RASSF6 and PF4V1 did not associate (P> or =0.26) and were in weaker LD with each other and with the IL8 variants (0.01< or =R2< or =0.49). Studies revealed differential expression between the IL8 promoter variant alleles (P<0.001). These results suggest that IL8 variants modify CF lung disease severity and have functional consequences.

The chemokine network. II. On how polymorphisms and alternative splicing increase the number of molecular species and configure intricate patterns of disease susceptibility

In this second review on chemokines, we focus on the polymorphisms and alternative splicings and on their consequences in disease. Because chemokines are key mediators in the pathogenesis of inflammatory, autoimmune, vascular and neoplastic disorders, a large number of studies attempting to relate particular polymorphisms of chemokines to given diseases have already been conducted, sometimes with contradictory results. Reviewing the published data, it becomes evident that some chemokine genes that are polymorphic have alleles that are found repeatedly, associated with disease of different aetiologies but sharing some aspects of pathogenesis. Among CXC chemokines, single nucleotide polymorphisms (SNPs) in the CXCL8 and CXCL12 genes stand out, as they have alleles associated with many diseases such as asthma and human immunodeficiency virus (HIV), respectively. Of CC chemokines, the stronger associations occur among alleles from SNPs in CCL2 and CCL5 genes and a number of inflammatory conditions. To understand how chemokines contribute to disease it is also necessary to take into account all the isoforms resulting from differential splicing. The first part of this review deals with polymorphisms and the second with the diversity of molecular species derived from each chemokine gene due to alternative splicing phenomena. The number of molecular species and the level of expression of each of them for every chemokine and for each functionally related group of chemokines reaches a complexity that requires new modelling algorithms akin to those proposed in systems biology approaches.

Genetic polymorphisms in immunoresponse genes TNFA, IL6, IL10, and TLR4 are associated with recurrent acute otitis media

OBJECTIVE

Cytokines and other inflammatory mediators are involved in the pathogenesis of otitis media. We hypothesized that polymorphisms in inflammatory response genes contribute to the increased susceptibility to acute otitis media in otitis-prone children.

PATIENTS AND METHODS

DNA samples from 348 children with > or = 2 acute otitis media episodes, who were participating in a randomized, controlled vaccination trial, and 463 healthy adult controls were included. Polymorphisms in TNFA, IL1B, IL4, IL6, IL10, IL8, NOS2A, C1INH, PARP, TLR2, and TLR4 were genotyped. Genotype distributions in children with recurrent acute otitis media were compared with those in controls. Within the patient group, the number of acute otitis media episodes before vaccination and the clinical and immunologic response to pneumococcal conjugate vaccinations were analyzed.

RESULTS

The IL6-174 G/G genotype was overrepresented in children with acute otitis media when compared with controls. In the patient group, TNFA promoter genotypes -238 G/G and -376 G/G and the TLR4 299 A/A genotype were associated with an otitis-prone condition. Furthermore, lower specific anticapsular antibody production after complete vaccination was observed in patients with the TNFA-238 G/G genotype or TNFA-863 A allele carriage. Finally, the IL10-1082 A/A genotype contributed to protection from the recurrence of acute otitis media after pneumococcal vaccination.

CONCLUSIONS

Variation in innate immunoresponse genes such as TNFA-863A, TNFA-376G, TNFA-238G, IL10-1082 A, and IL6-174G alleles in the promoter sequences may result in altered cytokine production that leads to altered inflammatory responses and, hence, contributes to an otitis-prone condition.

Association of interleukin-8 polymorphism and immunoglobulin G anti-toxin A in patients with Clostridium difficile-associated diarrhea

BACKGROUND & AIMS

Previous studies have shown that failure to produce serum antibodies to C. difficile (CD) toxin A is associated with more severe and recurrent C. difficile-associated diarrhea (CDAD); and that presence of AA genotype in the interleukin (IL)-8 gene promoter -251 position is associated with increased susceptibility to CDAD. This study examined the relationship between serum immunoglobulin G antibodies to CD toxin A and the presence of IL-8 AA genotype in hospitalized patients with CDAD.

METHODS

At enrollment, blood for host IL-8 genotype, serum for CD anti-toxin A antibody, and stool for IL-8 by enzyme-linked immunosorbent assay were obtained in CDAD patients and in CD-toxin-negative asymptomatic controls.

RESULTS

Nine of 24 (37.5%) CDAD and 3 of 20 (15%) controls were CD anti-toxin A positive (P = .095). Eleven of 24 (45.8%) CDAD subjects were positive for AA genotype compared with 5 of 20 (25.0%) controls (P = .0019). One of 11 (9.1%) CDAD with AA genotype were positive for anti-toxin A antibodies compared with 8 of 13 (61.5%) non-AA genotype CDAD (P < .0001). Fecal IL-8 concentration for the single antibody-positive CDAD subject with AA genotype was lower than the median level of 822 microg/mL seen in 10 anti-toxin A antibody-negative subjects with CDAD.

CONCLUSIONS

This study provided evidence that host susceptibility to C. difficile diarrhea is related both to a defective humoral immune response to CD toxin A and host IL-8 AA genotype.

A report of cytokine polymorphisms and COPD risk in Xuan Wei, China

Indoor air pollution has been documented as an important risk factor for chronic obstructive pulmonary disease (COPD), and inflammation is central to the development and progression of COPD. Single nucleotide polymorphisms (SNP) in some cytokine genes have been reported to be associated with COPD. We examined the association between 18 SNPs in 10 cytokine genes and COPD risk in a case-control study conducted in a population with high exposure to indoor smoky coal emissions. The study included 53 COPD cases and 122 healthy community controls. Carriers of the CSF2 117Ile allele had a 2.4-fold higher risk of COPD than the wild type (Thr/Thr) carriers (OR: 2.44; 95% CI: 1.10-5.41), and the AA genotype at IL8 -351 was associated with an increased risk of COPD (OR: 2.71; 95% CI: 1.04-7.04). When the combined effects of CSF2 117Ile and IL8 -351A were examined, individuals carrying at least one variant in both genes had a five-fold increased risk of COPD (OR: 5.14, 95% CI: 1.32-29.86). This study suggests that polymorphisms in both CSF2 and IL8 may play a role in the pathogenesis of COPD, at least in highly exposed populations. However, in view of our relatively small sample size, this study should be replicated in other populations with substantial exposure to indoor air pollutants such as polycyclic aromatic hydrocarbons (PAH) and particulate matter.

Assessment of the toll-like receptor 4 Asp299Gly, Thr399Ile and interleukin-8 -251 polymorphisms in the risk for the development of distal gastric cancer

Background

The intensity of the inflammation induced by Helicobacter pylori colonization is associated with the development of distal gastric cancer (GC). The host response to H. pylori has been related to genetic polymorphisms that influence both innate and adaptive immune responses.

Our aim was to investigate whether the presence of the TLR4 Asp299Gly, TLR4 Thr399Ile and IL-8-251 A/T polymorphisms had any influence in the development of distal GC in a Mexican population.

Methods

We studied 337 patients that were divided in two groups: 78 patients with histologically confirmed distal GC and 259 non-cancer controls. The presence of H. pylori in the control population was defined by positive results of at least two of four diagnostic tests: serology, histology, rapid urease test and culture. Human DNA was purified and genotyped for TLR4 Asp299Gly polymorphism by pyrosequencing, for TLR4 Thr399Ile by PCR-RFLP and for IL8-251 by the amplification refractory mutation system (ARMS)-PCR.

Results

The non-cancer control group was found to be in Hardy-Weinberg equilibrium at the polymorphic loci studied (chi-square _H-W = 0.58 for IL8-251, 0.42 for TLR4 Asp299Gly and 0.17 for TLR4 Thr399Ile). The frequencies of mutated alleles (homozygous plus heterozygous) were compared between cases and controls. We found no significant difference for TLR4- Asp299Gly [the 7.7% of distal GC patients and 7.7 % non-cancer controls (p = 0.82)] and for TLR4 Thr399Ile [the 1.3% of GC patients and the 5% of the control population (p = 0.2)]. In contrast, for IL-8-251 A/T, 80.77% of the GC patients and 66.4% in the control group age and gender matched had at least one copy of mutated allele (OR = 2.12, 95% CI = 1.1–4.2) (p = 0.023).

Conclusion

This study showed that the IL8-251*A allele could be related to the development of distal gastric cancer in this Mexican population.

Association of common polymorphisms in inflammatory genes with risk of developing cancers of the upper aerodigestive tract

OBJECTIVES

The purpose of this study was to investigate the role of polymorphisms of genes involved in inflammation in the risk of cancers of the upper aerodigestive tract (UADT).

METHODS

We have evaluated the role of polymorphisms in key genes related to inflammation, namely IL1B (rs1143627), COX2/PTGS2 (rs5275), and IL8 (rs4073) in a large case-control study comprising 811 UADT cancer cases and 1,083 controls.

RESULTS

An association was observed for squamous cell carcinoma of the pharynx for a polymorphism in the promoter of the IL1B gene, with an OR of 2.39 (95% CI = 1.19-4.81) for the homozygotes for the minor allele A promoter polymorphism of IL8 was associated with decreased risk of laryngeal cancer, with an OR of 0.70 (95% CI = 0.50-0.98) for carriers of the minor allele.

CONCLUSIONS

To our knowledge, this is the first report on the role of these polymorphisms with respect to UADT carcinogenesis. Our results suggest that inflammation-related polymorphisms play a role, albeit minor, in the risk of developing cancers of the upper aerodigestive tract.

Interleukin-8 and CXCR1 Receptor Functional Polymorphisms and Susceptibility to Acute Pyelonephritis

PURPOSE

We performed a case-control study in children diagnosed by the first episode of upper urinary tract infection with or without vesicoureteral reflux to evaluate the association of functional polymorphism of interleukin-8 (-251A>T and +2767A>G), and its receptor CXCR1 (+2607G>C).

MATERIALS AND METHODS

Genomic DNA was obtained from 265 children with a clinical and laboratory diagnosis of urinary tract infection who were recruited in northeast Italy. The children were subdivided as 173 who were dimercapto-succinic acid scan positive with positive static renal scintigraphy in acute conditions, consistent with the diagnosis of acute pyelonephritis, and 92 who were dimercapto-succinic acid scan negative. Genetic analysis for the same polymorphisms was also extended to a control population of 106 umbilical cord DNA samples.

RESULTS

Statistical analysis of genotype data showed that 1) the tested populations were in Hardy-Weinberg equilibrium, 2) there were significant differences between the dimercapto-succinic acid scan positive and negative groups (p=0.049), and the dimercapto-succinic acid scan positive group vs controls (p=0.032) in terms of interleukin-8 -251A>T polymorphism frequency, 3) there was also a significant difference in the distribution of IL-8 -251A>T and +2767A>G polymorphisms between dimercapto-succinic acid scan positive and negative children in the subgroup without vesicoureteral reflux (p=0.03 and 0.02, respectively) and 4) no significant differences were found in the frequency of the distribution of CXCR1 +2607G>C polymorphism in all groups.

CONCLUSIONS

These data suggest that the gene for the proinflammatory chemokine interleukin-8 is involved in susceptibility to acute pyelonephritis during upper urinary tract infection in children with or without vesicoureteral reflux.

Single nucleotide polymorphisms of tumor necrosis factor-alpha and the susceptibility to bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is the most common chronic lung disease of infancy. A "New" BPD has been characterized in preterm infants that may begin in utero, and then progress post-natally, resulting in arrested lung development and alveolar hypoplasia. Foundations for this "New" BPD may be derived from pro-inflammatory genes including tumor necrosis factor-alpha (TNFalpha). The hypothesis of the current study is that single nucleotide polymorphisms (SNPs) of the pro-inflammatory TNFalpha gene place preterm infants at increased risk for BPD. Preterm infants (105 in number) with birthweights <or=1 kg, who survived to at least 36 weeks postmenstrual age (PMA) or discharge were enrolled into this study. They were stratified for BPD according to their need for supplemental oxygen at 28 days and at 36 weeks PMA (non-, mild-, moderate-, or severe-BPD). DNA was extracted from these infants and subjected to analyses for the TNFalpha SNPs: -1,031, -863, -857, -308, and -238. The PHASE software (version 2.1) was used to reconstruct haplotypes and estimate their frequencies within the study population. Differences in birth weight (P < 0.001) and gestational age (P < 0.001), but not in racial distribution between the groups were found. Haplotype-specific analysis revealed no significant association between BPD severity and any of the 5-marker common haplotypes with 10 or more copies in this study population. Additionally, no significant association was observed in any three SNP haplotypes at -1,031, -863, and -857, and two SNP haplotypes at -308 and -238. We observed no association between BPD severity and the five TNFalpha SNPs investigated.

Polymorphism in the IL-8 gene, but not in the TLR4 gene, increases the severity of acute pancreatitis

BACKGROUND/AIM

Activated granulocytes and inflammatory mediators of the innate immune response play fundamental roles in the pathogenesis of acute pancreatitis. We studied whether polymorphisms of interleukin-8 (IL-8) and Toll-like receptor 4 (TLR4) genes correlate with the severity of acute pancreatitis.

METHODS

Patients with acute pancreatitis (n = 92) were grouped according to the severity of the disease on the basis of the Ranson scores. Healthy blood donors (n = 200) served as controls. The IL-8 -251 gene polymorphism was analyzed by amplification-refractory mutation system; the single-nucleotide polymorphisms (Asp299Gly and Thr399Ile) of TLR4 were investigated by using a real-time polymerase chain reaction method with melting point analysis.

RESULTS

The IL-8 A/T heterozygote mutant variants were detected with a significantly higher frequency among the patients with severe pancreatitis than among the healthy blood donors (60 vs. 42%; p = 0.0264, odds ratio = 2.071, 95% confidence interval = 1.101-3.896), while the frequency of the normal allelic genotype (TT) was higher among the patients with mild pancreatitis than in the group with severe pancreatitis (35 vs. 16%; p = 0.051, odds ratio = 2.917, 95% confidence interval = 1.089-7.811). There was no significant correlation between TLR4 polymorphisms and the acute pancreatitis itself, but nonsignificantly increased frequencies of Asp299Gly and Thr399Ile heterozygotes among patients with severe infected pancreatic necrosis could be observed relative to the patients with mild pancreatitis.

CONCLUSIONS

Determination of the frequency of IL-8 polymorphism in acute pancreatitis may be informative and may provide further evidence concerning the role of IL-8 in the severe form of this disease. The possible role of TLR4 polymorphism in the outcome of severe acute pancreatitis requires further investigations in a larger series of patients.

Inflammation-related gene polymorphisms and colorectal adenoma

Chronic inflammation has been reported to be a risk factor for colorectal neoplasia. The propensity to mount an inflammatory response is modified by germ line variation in cytokine and other inflammation-related genes. We hypothesized that a proinflammatory genotype would be positively associated with colorectal adenoma, a precursor of colorectal cancer. We investigated the association of colorectal adenoma with 19 single nucleotide polymorphisms in a range of important proinflammatory (IL1B, IL6, IL8, TNF, and LTA) and anti-inflammatory (IL4, IL10, and IL13) cytokines and other inflammation-related genes (PTGS2 and PPARG) in a case-control study of risk factors for colorectal polyps in which all participants (ages 18-74 years) had undergone colonoscopy or sigmoidoscopy. The study sample comprised 244 cases of colorectal adenoma and 231 polyp-free controls. Compared with being homozygous for the common allele, heterozygosity at the IL1B -31 (C>T) locus was associated with an odds ratio (OR) for colorectal adenoma of 1.8 [95% confidence interval (95% CI), 1.2-2.9]. Homozygous carriers of the IL8 -251-A allele were at 2.7-fold increased risk of adenoma (95% CI, 1.5-4.9) compared with homozygosity for the common T allele, whereas carriage of at least one IL8 -251-A allele conferred a 1.5 increased odds of disease (95% CI, 1.0-2.4). Among non-nonsteroidal anti-inflammatory drug users, there was a statistically significant association between the IL10 -819-T/T genotype and adenoma compared with the common IL10 -819-C/C genotype (OR, 3.9; 95% CI, 1.1-13.6), which was not evident among nonsteroidal anti-inflammatory drug users (OR, 0.7; 95% CI, 0.3-1.5; P(interaction) = 0.01). These exploratory data provide evidence that polymorphic variation in genes that regulate inflammation could alter risk for colorectal adenoma.

Respiratory syncytial virus disease mechanisms implicated by human, animal model, and in vitro data facilitate vaccine strategies and new therapeutics

Respiratory syncytial virus (RSV) is the leading cause of bronchiolitis, pneumonia, mechanical ventilation, and respiratory failure in infants in the US. No effective post-infection treatments are widely available, and currently there is no vaccine. RSV disease is the result of virus-induced airway damage and complex inflammatory processes. The outcome of infection depends on host and viral genetics. Here, we review disease mechanisms in primary RSV infection that are implicated by clinical studies, in vitro systems, and animal models. Defining RSV disease mechanisms is difficult because there is a wide range of RSV disease phenotypes in humans, and there are disparities in RSV disease phenotypes among the animal models of RSV infection. However, host factors identified by multiple lines of investigation as playing important roles in RSV pathogenesis are providing key insights. A better understanding of RSV molecular biology and RSV pathogenesis is facilitating rational vaccine design strategies and molecular targets for new therapeutics.

Bronchiolitis to asthma: a review and call for studies of gene-virus interactions in asthma causation

Viral infections are important causes of asthma exacerbations in children, and lower respiratory tract infections (LRTIs), caused by viruses such as respiratory syncytial virus (RSV) and rhinovirus (RV), are a leading cause of bronchiolitis in infants. Infants hospitalized with bronchiolitis are at significantly increased risk for both recurrent wheezing and childhood asthma. To date, studies addressing the incidence of asthma after bronchiolitis severe enough to warrant hospitalization have focused almost exclusively on RSV, but a number of recent studies suggest that other respiratory pathogens, including RV, may contribute as well. It is not known whether viral bronchiolitis directly contributes to asthma causation or simply identifies infants at risk for subsequent wheezing, as from an atopic predisposition or preexisting abnormal lung function. Alternatively, the properties of the infecting virus may be important. Thus, many possible determinants exist that may contribute to the severity of bronchiolitis and the subsequent development of asthma. One such determinant is the potential involvement of genetic susceptibility loci to asthma after viral bronchiolitis, a critical area that is just beginning to be evaluated. By clarifying the roles of both host- (genetic) and virus- (environment) specific factors that contribute to the frequency and severity of viral LRTI, it may be possible to determine if severe LRTIs cause asthma, or if asthma susceptibility predisposes patients to severe LRTI in response to viral infection. Characterizing these relationships offers the potential of identifying at-risk hosts in whom preventing or delaying infection could alter the phenotypic expression of asthma.

The cell biology of acute childhood respiratory disease: therapeutic implications

Respiratory syncytial virus (RSV), the recently identified human metapneumovirus (HMPV), and the human parainfluenza viruses (HPIVs), cause most cases of childhood croup, bronchiolitis, and pneumonia. Influenza virus also causes a significant burden of disease in young children, although its significance in children was not fully recognized until recently. This article discusses pathogens that have been studied for several decades, including RSV and HPIVs, and also explores the newly identified viral pathogens HMPV and human coronavirus NL63. The escalating rate of emergence of new infectious agents, fortunately meeting with equally rapid advancements in molecular methods of surveillance and pathogen discovery, means that new organisms will soon be added to the list. A section on therapies for bronchiolitis addresses the final common pathways that can result from infection with diverse pathogens, highlighting the mechanisms that may be amenable to therapeutic approaches. The article concludes with a discussion of the overarching impact of new diagnostic strategies.

Variation of interleukin 8 -251 A>T polymorphism in worldwide populations and intra-ethnic differences in Japanese populations

BACKGROUND

Interleukin-8 (IL8) is a member of the family of chemokines. The IL8 gene has polymorphic variations, and the genotype of IL8 -251 A>T is associated with smoking behavior and cancer progression.

METHOD

IL8 -251 A>T polymorphism were investigated in Japanese, from 5 different areas, in Ovambo, Turkish, Mongolian and Korean populations by PCR with confronting 2-pair primers (PCR-CTPP) analysis.

RESULTS

A subpopulation analysis of Japan revealed a north-to-south increase in the frequency of the IL8 -251 T allele. Among the 5 groups, the Japanese showed the highest frequency of mutant allele followed by the Turks. The distribution pattern in the Japanese was different from those of Mongolians and Koreans. In the Ovambo population, no mutant allele homozygote subject was found and the frequency of mutant alleles was the lowest, similar to that in Gambians.

CONCLUSION

The present study is the first to demonstrate the Japan population inter-prefecture differences in IL8 -251 A>T polymorphism as well as a certain genetic heterogeneity in the worldwide distribution of IL8 -251 A>T polymorphism. The distribution results may help define the true significance of IL8 -251 A>T polymorphism as a marker for smoking behavior in populations worldwide.