ADAM33 polymorphisms are associated with asthma susceptibility in a Japanese population

Association between ADAM33 polymorphisms and asthma risk: a systematic review and meta-analysis

Background

Asthma is a common complex chronic, inflammatory polygenic disease with heterogeneous manifestations, affecting individuals of all age groups and posing an immense burden on healthcare resources. A number of studies have identified the association between a disintegrin and metalloprotease 33 (ADAM33) polymorphisms and asthma risk, however, the results still remain inconclusive. The objective of the present study was to identify the effect of ADAM33 variants in asthma susceptibility.

Methods

Eligible case-control studies published between January 2000 and June 2018 was searched and retrieved from online electronic databases. The odds ratio (OR) with its 95% confidence interval (CI) was employed to calculate the effect.

Results

A total of 63 case-control studies were finally screened out, including 13,280 asthma patients and 13,340 controls. Eleven SNPs of ADAM33 gene were identified. Our results detected a significant association between ADAM33 T2, Q1, F + 1 and AA genotype of T + 1 polymorphisms and asthma risk in total population. Subgroup analysis by ethnicities showed that the alleles and genotypes of T2, Q1 and F + 1 polymorphisms were associated with asthma susceptibility among Asian populations, while V4 polymorphism was associated with asthma among Caucasian populations. Subgroup analysis by ages showed that T2, F + 1 and ST + 4 polymorphisms were associated with childhood asthma, while Q1 and V4 polymorphisms were associated with asthma risk in adults. Subgroup analysis by asthma severity showed that only the G allele of ADAM33 T1 polymorphism was associated with the severity of asthma when compared with the controls. In addition, T2, Q1 and F + 1 polymorphisms of ADAM33 were significantly associated with increased the asthma risk in Chinese asthma patients.

Conclusions

Our results found that T2, Q1 and F + 1 polymorphisms of ADAM33 gene might contribute to asthma risk. Future well-designed case-control studies with large population and more ethnicities are still needed to estimate the association.

ADAM33 gene polymorphisms identified to be associated with asthma in a Chinese Li population

A disintegrin and metalloprotease 33 (ADAM33) is an asthma susceptibility gene that has been proven to be present in certain human populations. The Li population is a minority ethnic group, most of whom maintain a distinctive lifestyle on Hainan Island in southern China. To the best of our knowledge, no previous study has established whether ADAM33 polymorphisms are associated with asthma in the Li population. Therefore, the ADAM33 polymorphisms in a Li population were investigated in the present study. A total of 150 asthma patients and 100 healthy subjects were enrolled in the present study, and their DNA samples were evaluated to analyze eight single-nucleotide polymorphisms (SNPs) on the ADAM33 gene. Asthma patients were subcategorized into low and high severity groups, and their SNP data were compared with the data of the control subjects. Single-marker and haplotype association was analyzed to demonstrate the association between ADAM33 SNPs and asthma using multiple genetic statistic tests. The results indicated significant differences in allele frequencies at the SNPs rs44707/T2 (P=0.008), rs2787094/V4 (P=0.028) and rs2280089/T+1 (P=0.021) between asthma patients and control subjects. The SNP rs44707/T2 was also found to be associated with the high severity group (P=0.024), although SNPs rs2787094/V4 were associated with the low severity group (P=0.019). Two haplotypes, GGAGAGT and GAAGGGT, were significantly associated with asthma (P=0.003 and 0.008, respectively). To the best of our knowledge, this is the first time that SNP rs2280089/T+1 has been reported to be associated with asthma in an Asian population. These data confirm that ADAM33 polymorphisms are associated with asthma susceptibility in the Li population and confirm the uniqueness of the Li minority population within China.

Genetic variants of ADAM33 are associated with asthma susceptibility in the Punjabi population of Pakistan

OBJECTIVE

A disintegrin and metalloproteinase 33 (ADAM33) gene has been considered as an asthma susceptibility gene due to its possible role in airway remodeling, abnormal cell proliferation, and differentiation. Association of this gene with asthma has been reported in several genetic studies on various populations. The current study aims to evaluate the association of ADAM33 gene polymorphisms with the risk of asthma in the Punjabi population of Pakistan.

METHOD

A total of 101 asthma patients and 102 age-matched healthy controls from Lahore, a city in Punjab, were recruited. ADAM33 single nucleotide polymorphisms (SNPs) T + 1[rs2280089], T2[rs2280090], T1[rs2280091], ST + 5[rs597980], ST + 4[rs44707], S2[rs528557], Q - 1[rs612709], and F + 1[rs511898] were genotyped in both patients and controls using single base extension and capillary electrophoresis-based genetic analyzer. The basic allelic and genotypic model was analyzed for association of the SNPs with asthma using SHEsis software. Haploview software was used to calculate pairwise linkage disequilibrium (LD) among six of the genotyped SNPs.

RESULTS

Of the 8 SNPs genotyped, only S2[rs528557] showed significant association with asthma (Allele p = 0.0189, Genotype p = 0.021). SNPs T + 1[rs2280089], T2[rs2280090], T1[rs2280091], ST + 4[rs44707], S2[rs528557], and Q - 1[rs612709] were found to be in moderate to strong LD. The significantly higher frequency of haplotype "AAGTCG" in healthy controls suggests a protective effect against asthma risk in the studied population (p = 0.0059).

CONCLUSION

These findings suggest that genetic variants of ADAM33 gene may play important roles in asthma susceptibility in the Punjabi population of Pakistan.

ADAM33 and ADAM12 genetic polymorphisms and their expression in Egyptian children with asthma

BACKGROUND

The ADAM family is involved in some pathologic processes, such as inflammation and asthma.

OBJECTIVES

To assess the association between ADAM33 and ADAM12 single-nucleotide polymorphisms (SNPs) with asthma risk and severity and to investigate the effect of ADAM33 and ADAM12 polymorphisms on expression of these proteases in sputum.

METHODS

Two SNPs of the ADAM33 gene, F+1 (rs511898) G/A and ST+4 (rs44707) A/C, and 2 SNPs of the ADAM12 gene, rs3740199 and rs1871054, were analyzed in 400 asthma cases and 200 controls aged 3 to 14 years using the polymerase chain reaction-restriction fragment length polymorphism method. Messenger RNA expression profile of ADAM33 and ADAM12 proteases in sputum from studied groups was determined by reverse transcription polymerase chain reaction.

RESULTS

ADAM33 F+1 homozygous mutant genotype (AA) and ST+4 heterozygous and homozygous mutant genotype (AC and CC) and mutant alleles of both polymorphisms were significantly associated with asthma risk and severity in moderate and severe subgroups. Patients with the ADAM12 (rs3740199) CC genotype were at increased risk for moderate and severe asthma. Messenger RNA levels of ADAM12 were significantly increased in asthmatic children compared with controls, whereas we were not able to detect the expression of ADAM33 in the sputum of the groups studied. The ADAM12 expression was significantly higher in homozygous CC (variant type) compared with homozygous GG (wild type) of both ADAM12 rs3740199 and rs1871054 in the asthmatic group.

CONCLUSION

Our analysis suggests a likely role for ADAM33 and ADAM12 in the development of asthma in Egyptian children. Furthermore, ADAM12 polymorphisms may affect ADAM12 expression in asthma.

The ADAM33 S2 polymorphism is associated with susceptibility to pediatric asthma in the Chinese Han population

BACKGROUND

The disintegrin and metalloprotease domain containing protein 33 (ADAM33) is a novel susceptibility gene for asthma and airway hyperresponsiveness, particularly in the Asian population. We investigated the influence of ADAM33 polymorphisms on the serum levels of ADAM33 and the susceptibility to pediatric asthma in the Chinese Han population.

METHODS

Polymerase chain reaction-restriction fragment length polymorphism analysis was employed to study the genotypic distribution of F+1, T1, and S2 in ADAM33 in a cohort of 120 pediatric asthma patients and 105 healthy controls. The serum levels of secreted ADAM33 protein were measured in all the study subjects using the enzyme-linked immunosorbent assay (ELISA).

RESULTS

This case-control study showed that the distribution of F+1 and T1 genotypes of ADAM33 was not significantly different between pediatric asthma patients and healthy controls (p > 0.05); however, the genotype and allele frequencies of the S2 polymorphism were significantly different between asthmatic patients and healthy controls (both p < 0.05). In addition, the frequency of CGC and CGG haplotypes exhibited statistically significant differences, with lower CGC and higher CGG frequencies found in the case group compared to the control group. Finally, in comparison to healthy controls, the serum levels of ADAM33 protein were significantly lower in patients carrying the S2 polymorphism.

CONCLUSION

Our results provide evidence that the ADAM33 S2 polymorphism is associated with increased susceptibility to pediatric asthma and that the CGG haplotype for the F+1, T1, and S2 polymorphisms is associated with an elevated risk of pediatric asthma in the Han population, whereas the CGC haplotype appears to confer a protective effect. Our results may prove useful for population-based screening to affect early intervention.

An ADAM33 polymorphism associates with progression of preschool wheeze into childhood asthma: a prospective case-control study with replication in a birth cohort study

BACKGROUND

The influence of asthma candidate genes on the development from wheeze to asthma in young children still needs to be defined.

OBJECTIVE

To link genetic variants in asthma candidate genes to progression of wheeze to persistent wheeze into childhood asthma.

MATERIALS AND METHODS

In a prospective study, children with recurrent wheeze from the ADEM (Asthma DEtection and Monitoring) study were followed until the age of six. At that age a classification (transient wheeze or asthma) was based on symptoms, lung function and medication use. In 198 children the relationship between this classification and 30 polymorphisms in 16 asthma candidate genes was assessed by logistic regression. In case of an association based on a p<0.10, replication analysis was performed in an independent birth cohort study (KOALA study, n = 248 included for the present analysis).

RESULTS

In the ADEM study, the minor alleles of ADAM33 rs511898 and rs528557 and the ORMDL3/GSDMB rs7216389 polymorphisms were negatively associated, whereas the minor alleles of IL4 rs2243250 and rs2070874 polymorphisms were positively associated with childhood asthma. When replicated in the KOALA study, ADAM33 rs528557 showed a negative association of the CG/GG-genotype with progression of recurrent wheeze into childhood asthma (0.50 (0.26-0.97) p = 0.04) and no association with preschool wheeze.

CONCLUSION

Polymorphisms in ADAM33, ORMDL3/GSDMB and IL4 were associated with childhood asthma in a group of children with recurrent wheeze. The replication of the negative association of the CG/GG-genotype of rs528557 ADAM33 with childhood asthma in an independent birth cohort study confirms that a compromised ADAM33 gene may be implicated in the progression of wheeze into childhood asthma.

Association between genetic polymorphisms in the ADAM33 gene and asthma risk: a meta-analysis

The aim of this study was to evaluate the associations between the rs3918396 G>A and rs528557 C>G polymorphisms in the disinterring and metalloproteinase domain 33 (ADAM33) gene and asthma risk. We searched CISCOM, CINAHL, Web of Science, PubMed, Google Scholar, EBSCO, Cochrane Library, and CBM databases from inception through August 1st, 2013 without language restrictions. Meta-analysis was performed using the STATA 12.0 software. Crude odds ratios (ORs) with their 95% confidence intervals (95% CI) were calculated. Thirteen case-control studies were included with a total of 7104 asthma patients and 8172 healthy controls. Our meta-analysis results revealed that ADAM33 rs528557 C>G polymorphism was associated with an increased risk of asthma (all p<0.05). However, we found no correlation between the ADAM33 rs3918396 G>A polymorphism and asthma risk (all p>0.05). Subgroup analysis by ethnicity indicated that the ADAM33 rs528557 C>G polymorphism might be strongly associated with an increased risk of asthma among both Caucasian and Asian populations (All p<0.05). No significant association was found between the ADAM33 rs3918396 G>A polymorphism and the risk of asthma among the studied ethnicities (All p>0.05). The present meta-analysis suggests that the ADAM33 rs528557 C>G polymorphism may contribute to susceptibility to asthma. Thus, the ADAM33 rs528557 C>G polymorphism may be utilized as a biomarker for early diagnosis of asthma.

Association of a disintegrin and metalloprotease 33 gene polymorphisms with asthma

Various studies reported a disintegrin and metalloprotease 33 (ADAM33) as an important susceptibility gene for asthma, which is frequently detected among certain populations. The aim of the present study was to investigate the association between single-nucleotide polymorphisms (SNPs) of the ADAM33 gene and asthma. Our case-control study included 183 patients (73 male and 110 female, mean age 42.93±13.48 years) who were admitted in the First Affiliated Hospital of Xinjiang Medical University between February, 2012 and May, 2013 and 155 healthy controls (66 male and 89 female, mean age 41.14±14.10 years). Allele-specific polymerase chain reaction technology and DNA testing training methods were applied to detect the T2 and ST+5 polymorphisms of the ADAM33 gene. The data were statistically analyzed to determine whether there exists an association between these genotypes and asthma-related morbidity. The genotypes and allele frequencies of the T2 and ST+5 SNPs of ADAM33 were not found to be significantly associated with asthma risk when compared between asthmatic patients and healthy controls (P>0.05). In addition, there was no association of the investigated SNPs with the severity of asthma. There was no significant difference in the forced vital capacity and the forced expiratory volume between patients with the ADAM33 T2 and ST+5 genotype. In conclusion, our results suggested that the T2 and ST+5 ADAM33 gene polymorphisms do not confer a significant risk of asthma or affect its severity in the population investigated.

Associations of genetic variants in ADAM33 and TGF-β1 genes with childhood asthma risk

The aim of the present study was to explore the associations of genetic variants in the ADAM33 and TGF-β1 genes with the risk of childhood asthma. A total of 299 asthmatic children and 311 healthy controls were recruited in the hospital-based case-control study. The asthmatic subjects were further divided into mild and severe groups according to disease severity. Single-nucleotide polymorphisms (SNP) at ADAM33 V4, T2, S2 and T1, and TGF-β1 C-509T and T869C were selected and detected with PCR-RFLP. The associations of the SNPs with asthma risk and severity were analyzed. The associations between the haplotypes of ADAM33 and TGF-β1 were also evaluated. Compared with the GG genotype, the GC and CC genotypes at V4 were associated with an increased asthma risk in children and the ORs were 2.92 and 10.56, respectively. Compared with the CC genotype, the CT/TT genotype at C-509T was associated with an increased asthma risk and the OR was 2.26. Subsequent to stratification by asthma severity, compared with the V4 GG genotype, it was found that the CG and CC genotypes were associated with a mild asthma risk and the ORs were 3.00 and 5.99, respectively. The SNP at C-509T (CT/TT vs. CC) was associated with mild asthma (OR=2.34), whereas a marginally significant association was detected between the SNP (CT/TT vs. CC) and severe asthma risk (OR=2.19). The haplotype analysis revealed that, compared with the GGCA haplotype of ADAM33, significant associations of the haplotypes of CGCG, CGGA, GACA, GACG and GAGA with asthma risk were observed, and the ORs were 31.12, 12.24, 4.73, 30.85 and 4.83, respectively. No significant association was detected between the TGF-β1 haplotypes and asthma risk. The genetic variants at V4 and C-509T had the potential to modify the childhood asthma risk and the associations showed no notable difference with the disease severity. Thus, ADAM33 haplotypes provided more useful information in the prediction of asthma risk.

Association of matrix metalloproteinase 8 genetic polymorphisms with bronchial asthma in a Japanese population

Asthma has a strong genetic component. The final disease phenotype results from complex interactions between environment and multiple genes of small-to-modest effects. We investigated whether the polymorphism in genes encoding inflammatory mediators and cytokines is important for solving the onset and progression of asthma. We investigated whether 31 single nucleotide polymorphisms (SNPs) in genes encoding cytokines or monokines (interleukin [IL]-5R, matrix metalloproteinase [MMP] 8, beta2 adrenergic receptor, cytotoxic T-lymphocyte–associated antigen 4, IL-3, C-reactive protein, cytochrome P450 (CYP) 2C9, CYP3A4, a disintegrin and metalloproteinase [ADAM] 33, cysteinyl leukotriene receptor [CysLTR] 1, CysLTR2, eosinophilic cationic protein, glucocorticoid receptor, and leukotriene A 4 hydrolase) are related to asthma development in 206 Japanese bronchial asthma patients and 127 healthy controls. Using multifactor dimensionality reduction (MDR), we identified rs17099451 in MMP8, using a single locus model, with a mean cross-validation of 87.0%. Using a two-locus model, combinations of MMP8 and rs44707 in ADAM33, and MMP8 and rs40401 in IL-3, were identified, with mean cross-validation consistencies reaching 45.0%. Of the SNPs selected by the MDR method, rs17099451 in MMP8 and rs40401 in IL-3 were regarded as the most significant results in a 2 × 2 dominant model analysis. The finding that an MMP8 allele was most strongly related to asthma development indicates that metalloproteinase function is crucial to the airflow limitation process involved in this disease.

ADAM33 polymorphisms are associated with asthma and a distinctive palm dermatoglyphic pattern

A close correlation between asthma and palm dermatoglyphic patterns has been observed in previous studies, but the underlying genetic mechanisms have not been investigated. A disintegrin and metalloprotein-33 (ADAM33) polymorphisms are important in the development of asthma and other atopic diseases. To investigate the underlying mechanisms of the association between asthma and distinctive palm dermatoglyphic patterns, thirteen ADAM33 single-nucleotide polymorphisms (SNPs) were analyzed for the association between asthma and palm dermatoglyphic patterns in a population of 400 asthmatic patients and 200 healthy controls. Based on the results, five SNPs, rs44707 (codominant model, P=0.031; log-additive model, P=0.0084), rs2787094 (overdominant model, P=0.049), rs678881 (codominant model, P=0.028; overdominant model, P=0.0083), rs677044 (codominant model, P=0.013; log-additive model, P=0.0033) and rs512625 (dominant model, P=0.033), were associated with asthma in this population. Two SNPs, rs44707 (dominant model, P=0.042) and rs2787094 (codominant model, P=0.014; recessive model, P=0.0038), were observed in the asthma patients with the distinctive palm pattern. As rs44707 and rs2787094 are associated with asthma and a distinctive palm pattern, the data suggest that ADAM33 polymorphisms are correlated with asthma and may be the underlying genetic basis of the association between asthma and palm dermatoglyphic patterns.

Association between ADAM33 S2 and ST+4 polymorphisms and susceptibility to asthma: a meta-analysis

OBJECTIVE

The aim of this study was to determine whether ADAM33 (a disintegrin and metalloproteinase domain 33) polymorphisms confer susceptibility to asthma in different populations.

METHODS

We performed a meta-analysis on the association between the ADAM33 S2, ST+4, F+1, S1, and V4 polymorphisms and asthma.

RESULTS

Thirteen studies in ten reports, which included 4942 patients and 7933 controls, were available for the meta-analysis. Meta-analysis stratified by ethnicity indicated an association between the ADAM33 S2 2 allele and asthma in Europeans (OR=0.912, 95% CI=0.851-0.977, p=0.009). Meta-analysis revealed an association between asthma and the ADAM33 ST+4 2 allele (OR=0.783, 95% CI=0.762-0.999, p=0.048). Stratification by ethnicity indicated an association between the ADAM33 ST+4 polymorphism and asthma in Asians. Stratification by age indicated an association between the ADAM33 ST+4 2 allele and asthma in adults (OR=0.863, 95% CI=0.782-0.964, p=0.008). However, no association was found between asthma and the ADAM33 F+1, S1, and V4 polymorphisms.

CONCLUSIONS

This meta-analysis demonstrates that the ADAM33 S2 polymorphism confers susceptibility to asthma in Europeans and the ADAM33 ST+4 polymorphism is associated with asthma in Asians and adults.

Association of ADAM33 gene polymorphisms with asthma in the Uygur population of China

Asthma is one of the most common chronic respiratory diseases, affecting ∼300 million children and adults worldwide. Previous studies identified a disintegrin and metalloprotease domain 33 (ADAM33) as an important susceptibility gene for asthma in patients of different nationalities; however, it is unknown whether this relationship exists in ethnically diverse populations. The present study focused on the association between single-nucleotide polymorphisms (SNPs) of the ADAM33 gene and asthma in the Uygur population of China. Three SNPs of ADAM33 (T1, S+1 and F+1) were genotyped in a case-control study among the Chinese Uygur population, involving 126 adult asthmatic patients and 126 healthy controls. The frequency of the ADAM33 T1 C allele among asthma patients was significantly higher compared to healthy controls (20.6 vs. 11.1%, P=0.003). The distribution of ADAM33 genotypes differed significantly between the two groups. The frequency of the T1 TC genotype was higher among patients compared to healthy controls [odds ratio (OR)=2.118, P=0.016] and the variant genotype, TC+CC, increased the risk of asthma (OR=2.244, P=0.005). Following adjustment for confounding factors, the ORs of TC and TC+CC for asthma were 2.317 and 2.522, respectively. There was a significant decrease in the forced expiratory volume (FEV₁) levels in patients with the TC genotype compared to the TT genotype of T1. Haplotype analysis revealed that the frequencies of Hap5 (CAC) and Hap6 (CAT) were significantly higher among asthmatic patients compared to healthy controls (P=0.024 and 0.016, respectively). The genotype and allele frequencies of SNP S+1 and F+1 were not statistically different between asthmatic patients and controls. In conclusion, the ADAM33 T1 SNP may affect susceptibility to asthma in the Chinese Uygur population.

Haplotypic association of ADAM33 (T+1, S+1 and V - 3) gene variants in genetic susceptibility to asthma in Indian population

AIM

The aim of this study was to find out if the ADAM33 gene polymorphisms T+1(A>G), S+1(T>A) and V - 3(C>T) and their haplotypes play any role in genetic susceptibility to asthma.

SUBJECTS AND METHODS

Three hundred and ninety healthy controls and 386 asthmatic patients from Lucknow, India, were recruited for the study. Subjects were aged between 1-50 years. Among total recruited asthma cases, 95 (24.6%) had mild intermittent asthma, 235 (60.9%) had mild persistent asthma and 56 (14.5%) had moderate persistent asthma. Genotyping was carried out using the Polymerase Chain Reaction and Restriction Fragment Length polymorphism (PCRRFLP) method.

RESULTS

No significant differences in the genotype or allele frequencies of ADAM33 gene polymorphisms between asthmatic patients and healthy controls were found [p-value>0.05 (All the p-values were Bonferroni corrected)]. Also, no association of studied SNPs with the severity of the disease asthma was observed. However, the TTA haplotype was observed to be associated with asthma (OR = 3.4; 95%CI = 1.4-8.7; p = 0.002).

CONCLUSIONS

SNPs, T+1, S+1 and V - 3 do not individually confer any significant risk of asthma or its severity, but haplotype analysis suggests all three polymorphisms together play an important role in the disease of asthma.

Control of allergen-induced inflammation and hyperresponsiveness by the metalloproteinase ADAMTS-12

A disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) constitute a family of endopeptidases related to matrix metalloproteinases. These proteinases have been largely implicated in tissue remodeling associated with pathological processes. Among them, ADAMTS12 was identified as an asthma-associated gene in a human genome screening program. However, its functional implication in asthma is not yet documented. The present study aims at investigating potential ADAMTS-12 functions in experimental models of allergic airways disease. Two different in vivo protocols of allergen-induced airways disease were applied to the recently generated Adamts12-deficient mice and corresponding wild-type mice. In this study, we provide evidence for a protective effect of ADAMTS-12 against bronchial inflammation and hyperresponsiveness. In the absence of Adamts12, challenge with different allergens (OVA and house dust mite) led to exacerbated eosinophilic inflammation in the bronchoalveolar lavage fluid and in lung tissue, along with airway dysfunction assessed by increased airway responsiveness following methacholine exposure. Furthermore, mast cell counts and ST2 receptor and IL-33 levels were higher in the lungs of allergen-challenged Adamts12-deficient mice. The present study provides, to our knowledge, the first experimental evidence for a contribution of ADAMTS-12 as a key mediator in airways disease, interfering with immunological processes leading to inflammation and airway hyperresponsiveness.

Association between ADAM33 T1 polymorphism and susceptibility to asthma in Asians

OBJECTIVE

The aim of this study was to determine whether the ADAM33 (a disintegrin and metalloproteinase domain 33) T1 (rs2280091), T2 (rs2280090), and ST+7 (rs574174) polymorphisms confer susceptibility to asthma.

METHODS

A meta-analysis stratified by ethnicity and age was conducted on associations between the ADAM33 T1, T2, and ST+7 polymorphisms and asthma.

RESULTS

Eleven studies, which included 4,124 patients and 7,094 controls, were available for the meta-analysis. Meta-analysis revealed an association between asthma and the ADAM33 T1 GG genotype [odds ratio (OR) = 2.257, 95 % confidence interval (CI) = 1.577-3.228, p = 8.42 × 10(-7)]. Stratification by ethnicity indicated an association between this genotype and asthma in Asians (OR = 2.683, 95 % CI = 1.799-4.001, p = 1.31 × 10(-7)), and stratification by age indicated an association between it and asthma in adults (OR = 1.895, 95 % CI = 1.005-3.573, p = 0.048). However, no association was found between asthma and the ADAM33 T2 and ST+7 polymorphisms.

CONCLUSIONS

This meta-analysis demonstrates that the ADAM33 T1 polymorphism confers susceptibility to asthma in Asians, but no association was found between the ADAM33 T2 and ST+7 polymorphisms and asthma susceptibility.

Association of ADAM33 gene polymorphisms with adult-onset asthma and its severity in an Indian adult population

ADAM33, a member of the ADAM (a disintegrin and metalloprotease) gene family, is an asthma susceptibility gene originally identified by positional cloning. In the present study, we investigated the possible association of five single-nucleotide polymorphisms (SNPs) in the ADAM33 (rs511898, rs528557, rs44707, rs597980 and rs2787094) with adult-onset asthma in an Indian population. The study included 175 patients with mild intermittent (n = 44), mild persistent (n = 108) or moderate persistent (n = 23) subgroups of asthma, and 253 nonasthmatic control individuals. SNPs were genotyped with the help of restriction fragment length polymorphism polymerase chain reaction (RFLP-PCR) method, and data were analysed using chi-square test and logistic regression model. Bonferroni's correction for multiple comparisons was applied for each hypothesis. Genotypes and allele frequencies of SNPs rs511898 and rs528557 were significantly associated with adult-onset asthma (P = 0.010-<0.001). A significant association of the homozygous mutant genotype and mutant alleles of SNPs rs2787094, rs44707 and rs597980 with the asthma was also observed (P = 0.020-<0.001). A positive association between asthma and haplotypes AGCCT, GGCCT, AGACT, GCAGT, GGACT, ACCCC and AGACC were also found (P = 0.036-<0.001, OR = 2.07-8.49). Haplotypes AGCGT, GCAGC, ACAGC, ACAGT, GGAGC and GGCGT appear to protect against asthma (P = 0.013-<0.0001, OR = 0.34-0.10). Our data suggest that ADAM33 gene polymorphisms serve as genetic risk factors for asthma in Indian adult population.

Association of ADAM33 polymorphisms with childhood asthma in a northern Chinese population

BACKGROUND

Genetic factors contribute to the increasing incidence of childhood asthma. The ADAM33 (a disintegrin and metalloprotease domain-containing protein 33) gene, discovered through positional cloning, is the first to be associated with asthma and bronchial hyperresponsiveness. This case-control study conducted in a Han Chinese population in northern China compared the genotypes of child asthmatic patients to healthy controls for the presence of 6 single nucleotide polymorphisms (SNPs) in the ADAM33 gene.

METHODS

The study population was composed of 412 children with asthma and 397 healthy controls. We genotyped 6 SNPs (F+1, T+1, T2, T1, V4, and Q-1) of ADAM33 with the PCR-restriction fragment length polymorphism (PCR-RFLP) method. Data were statistically analyzed to determine if an association existed between these genotypes and childhood asthma morbidity.

RESULTS

Three SNPs (T+1, T1, and V4) and 4 haplotypes (H1, H3, H5, and H8) were strongly associated with childhood asthma in children of northern China compared to healthy controls (P<0.05), whereas the other tested SNPs and haplotypes demonstrated no significant relationship.

CONCLUSION

The ADAM33 gene plays an important role in facilitating susceptibility to childhood asthma in this Han Chinese population.

Association of ADAM33 gene polymorphisms with asthma in a Chinese population

BACKGROUND AND AIM

Asthma is a very common disease involving genetic and environmental factors. A disintegrin and metalloproteinase 33 (ADAM33) has been one of the most exciting candidate genes for asthma since its first association with the disease in the white population. Recently, studies on the association of ADAM33 gene polymorphisms with the risk of asthma have been controversial. We therefore focused on testing the hypothesis that either single-nucleotide polymorphisms (SNPs) of the ADAM33 gene may be associated with asthma risk. The aim of this study was to evaluate the potential relationship between polymorphisms of ADAM33 and asthma in a Han population in China.

METHODS

A case control study was conducted in a Han population of eastern Chinese population. A total of 329 asthma patients and a control group of 316 healthy volunteers were recruited for this study. Four polymorphic sites (F+1, S2, T2 and V4) were selected for genotyping. Genotypes were determined by the allele-specific polymerase chain reaction with fluorescence melting curves and DNA sequencing method. Data were analysed using the chi-squared test software.

RESULTS

Statistically significant differences in the distributions of the S2 site between patients and controls were observed (χ2=7.140, P<0.05).

CONCLUSION

These preliminary results suggest an association between ADAM33 polymorphisms S2 C/G and asthma in a Chinese Han population. The SNPs (F+1 C/T, T2 G/A and V4 C/G) of the ADAM33 gene may be the causal variants in asthma disease, but the strength of this evidence is limited by our small sample size.

Association of ADAM33 gene polymorphisms with asthma in Indian children

Asthma is the most common chronic disorder in childhood, and asthma exacerbation is an important cause of childhood morbidity and hospitalization. In the present study, the relationship between single-nucleotide polymorphisms (SNPs) of the ADAM33 gene and asthma in Indian children has been examined using a case-control study. Five SNPs of the ADAM33 gene, F+1(rs511898) G/A, S2 (rs528557) G/C, ST+4 (rs44707) A/C, ST+5 (rs597980) C/T and V4 (rs2787094) C/G, were analyzed in 211 asthma cases and 137 controls aged 1-15 years using the PCR-restriction fragment length polymorphism method. Data were statistically analyzed using the χ(2)-test and logistic regression model. Haplotype estimation and linkage disequilibrium were conducted using the expectation-maximization algorithm. The genotypes and allele frequencies of SNPs S2 and ST+5 of the ADAM33 gene were significantly associated with asthma risk (P = 0.020 - < 0.001), whereas F+1, ST+4, V4 homozygous mutant genotypes and mutant alleles were significantly associated with increased asthma risk (P = 0.031 - < 0.001). A positive association was also found with haplotypes AGCCT, GGACT and AGCCC (P = < 0.001, odds ratio (OR) = 6.10-6.50), whereas ACAGT, AGCGC, AGCGT, GCAGC and GCCGT showed protective association with asthma (P = 0.019-0.000, OR = 0.50-0.20). Taken together, out results suggest that ADAM33 gene polymorphisms may modify individual susceptibility to develop childhood asthma in the Indian population.

Association of ADAM33 gene with susceptibility to COPD in Tibetan population of China

Chronic obstructive pulmonary disease (COPD) is a common, complex disorder associated with substantial morbidity and mortality, influenced by both environmental factor and genetic factor. ADAM33 gene was found to be associated with asthma, declined lung function and COPD. The purpose of the study was to test whether SNPs in ADAM33 were associated with COPD in Tibetan population of China. Polymerase chain reaction-restriction fragment length polymorphism was carried out to genotype the eight SNPs (V4, T2, T1, S2, S1, Q-1 and F + 1) of ADAM33 on 240 COPD patients and 221 healthy individuals. Four SNPs (V4, T2, T1 and S1) and four haplotypes (H2 CGAAGAGC, H5 GAGAGAGC, H9 GAAAGAGC and H6 CGGGGAGC of ADAM33 gene were associated with COPD significantly (defined as P < 0.05). The results indicate that there is an association between ADAM33 polymorphisms and COPD in Tibetan population of China.

Association of IL-4 and ADAM33 gene polymorphisms with asthma in an Indian population

There are more than 100 candidate genes of asthma located on 23 human chromosomes. Interleukin-4 (IL-4), located on chromosome 5q31, and ADAM33, located on chromosome 20p13, and some single nucleotide polymorphisms (SNPs) of these genes have been shown to be associated with asthma and its manifestations in different populations. The most prominent SNPs of IL-4 and ADAM33 are 589C>T and 400A>G, respectively. There are also controversial reports on the association of these SNPs with asthma. In the present study, we analyzed these two SNPs in 100 patients with asthma and 50 controls through PCR amplification and restriction digestion to evaluate association of these two SNPs with asthma. The nonsignificant differences were observed for the IL-4 promoter polymorphism C589T and the ADAM33 T1 polymorphism between asthmatic patients and controls (P = 0.638 and 0.943, respectively). Our data revealed that there is no association of these SNPs with asthma indicating that other SNPs of these genes or other genes might be involved in the manifestation of asthma.

Positive association between aspirin-intolerant asthma and genetic polymorphisms of FSIP1: a case-case study

BACKGROUND

Aspirin-intolerant asthma (AIA), which is caused by non-steroidal anti-inflammatory drugs (NSAIDs) such as aspirin, causes lung inflammation and reversal bronchi reduction, leading to difficulty in breathing. Aspirin is known to affect various parts inside human body, ranging from lung to spermatogenesis. FSIP1, also known as HDS10, is a recently discovered gene that encodes fibrous sheath interacting protein 1, and is regulated by amyloid beta precursor protein (APP). Recently, it has been reported that a peptide derived from APP is cleaved by alpha disintegrin and metalloproteinase 33 (ADAM33), which is an asthma susceptibility gene. It has also been known that the FSIP1 gene is expressed in airway epithelium.

OBJECTIVES

Aim of this study is to find out whether FSIP1 polymorphisms affect the onset of AIA in Korean population, since it is known that AIA is genetically affected by various genes.

METHODS

We conducted association study between 66 single nucleotide polymorphisms (SNPs) of the FSIP1 gene and AIA in total of 592 Korean subjects including 163 AIA and 429 aspirin-tolerant asthma (ATA) patients. Associations between polymorphisms of FSIP1 and AIA were analyzed with sex, smoking status, atopy, and body mass index (BMI) as covariates.

RESULTS

Initially, 18 SNPs and 4 haplotypes showed associations with AIA. However, after correcting the data for multiple testing, only one SNP showed an association with AIA (corrected P-value = 0.03, OR = 1.63, 95% CI = 1.23-2.16), showing increased susceptibility to AIA compared with that of ATA cases. Our findings suggest that FSIP1 gene might be a susceptibility gene for aspirin intolerance in asthmatics.

CONCLUSION

Although our findings did not suggest that SNPs of FSIP1 had an effect on the reversibility of lung function abnormalities in AIA patients, they did show significant evidence of association between the variants in FSIP1 and AIA occurrence among asthmatics in a Korean population.

Role of ADAM and ADAMTS metalloproteinases in airway diseases

Lungs are exposed to the outside environment and therefore to toxic and infectious agents or allergens. This may lead to permanent activation of innate immune response elements. A Disintegrin And Metalloproteinases (ADAMs) and ADAMs with Thrombospondin motifs (ADAMTS) are proteinases closely related to Matrix Metalloproteinases (MMPs). These multifaceted molecules bear metalloproteinase and disintegrin domains endowing them with features of both proteinases and adhesion molecules. Proteinases of the ADAM family are associated to various physiological and pathological processes and display a wide spectrum of biological effects encompassing cell fusion, cell adhesion, "shedding process", cleavage of various substrates from the extracellular matrix, growth factors or cytokines... This review will focus on the putative roles of ADAM/ADAMTS proteinases in airway diseases such as asthma and COPD.

A Six-SNP haplotype of ADAM33 is associated with asthma in a population of Cartagena, Colombia

BACKGROUND

A disintegrin and metalloprotein-33 (ADAM33) participates in the bronchial remodeling process in asthma, and genetic analyses pointed it out as a candidate gene in asthma.

METHODS

To analyze the association between ADAM33 and asthma and total and mite-specific IgE levels in a population of the Caribbean Coast of Colombia, we genotyped 6 single-nucleotide polymorphisms of ADAM33 in 429 asthmatics, 401 controls and 116 family trios using fluorogenic probes. Total and specific IgE against Blomia tropicalis and Dermatophagoides pteronyssinus were determined by ELISA. Case-control and family-based analyses were performed. Case-control association analyses were corrected by population stratification using a set of 52 ancestry-informative markers.

RESULTS

Eight common haplotypes were identified; among them, H4 (GCAGGG) was associated with asthma in the family group (Z score: -2.049, p = 0.04). We also found an association between the TT genotype of ST+7 and asthma in the case-control study (p = 0.05) that disappeared after correcting for multiple testing. In the family-based analysis, this genotype was a risk factor for asthma (p = 0.01), high total IgE (Z score: 2.546, p = 0.01) and high specific IgE against B. tropicalis (p = 0.02) and D. pteronyssinus (Z score: 2.414, p = 0.01). V4 was associated with specific IgE against B. tropicalis (p = 0.03); T2 with asthma (p = 0.03), high total IgE (p = 0.02) and IgE against D. pteronyssinus (p = 0.03) and T1 with high total IgE (p = 0.04). None of these associations was maintained after correction for multiple testing.

CONCLUSIONS

Our findings suggest a relevant role of ADAM33 in thepathogenesis of asthma in this population.

ADAM8: a new therapeutic target for asthma

BACKGROUND

A proteinase with a disintegrin and a metalloproteinase domain-8 (ADAM8) has been linked to asthma.

OBJECTIVE

To explore whether ADAM8 is a therapeutic target for asthma.

METHODS

We reviewed literature on ADAM8's function and expression and activities in lungs of humans and mice with allergic airway inflammation (AAI). We used these data to generate hypotheses about the contributions of ADAM8 to asthma pathogenesis.

CONCLUSIONS

ADAM8 levels are increased in airway epithelium and airway inflammatory cells in mice with AAI and human asthma patients. Data from murine models of AAI indicate that ADAM8 dampens airway inflammation. It is not clear whether ADAM8 contributes directly to structural remodeling in asthmatic airways. Additional studies are required to validate ADAM8 as a therapeutic target for asthma.

Adam33 polymorphisms are associated with COPD and lung function in long-term tobacco smokers

Background

Variation in ADAM33 has been shown to be important in the development of asthma and altered lung function. This relationship however, has not been investigated in the population susceptible to COPD; long term tobacco smokers. We evaluated the association between polymorphisms in ADAM33 gene with COPD and lung function in long term tobacco smokers.

Methods

Caucasian subjects, at least 50 year old, who smoked ≥ 20 pack-years (n = 880) were genotyped for 25 single nucleotide polymorphisms (SNPs) in ADAM33. COPD was defined as an FEV1/FVC ratio < 70% and percent-predicted (pp)FEV1 < 75% (n = 287). The control group had an FEV1/FVC ratio ≥ 70% and ppFEV₁ ≥ 80% (n = 311) despite ≥ 20 pack years of smoking. Logistic and linear regressions were used for the analysis. Age, sex, and smoking status were considered as potential confounders.

Results

Five SNPs in ADAM33 were associated with COPD (Q-1, intronic: p < 0.003; S1, Ile → Val: p < 0.003; S2, Gly → Gly: p < 0.04; V-1 intronic: p < 0.002; V4, in 3' untranslated region: p < 0.007). Q-1, S1 and V-1 were also associated with ppFEV1, FEV1/FVC ratio and ppFEF25–75 (p values 0.001 – 0.02). S2 was associated with FEV1/FVC ratio (p < 0.05). The association between S1 and residual volume revealed a trend toward significance (p value < 0.07). Linkage disequilibrium and haplotype analyses suggested that S1 had the strongest degree of association with COPD and pulmonary function abnormalities.

Conclusion

Five SNPs in ADAM33 were associated with COPD and lung function in long-term smokers. Functional studies will be needed to evaluate the biologic significance of these polymorphisms in the pathogenesis of COPD.

Association of ADAM33 gene polymorphisms with adult allergic asthma and rhinitis in a Chinese Han population

Background

Rhinitis and asthma are very common diseases involving genetic and environmental factors. Most patients with asthma also have rhinitis, which suggests the concept of 'one airway, one disease.' A disintegrin and metalloproteinase 33 (ADAM33) is the first asthma-susceptible gene to be discovered by positional cloning. To evaluate the potential influence of ADAM33 gene polymorphisms on allergic rhinitis (AR) and allergic asthma (AS), a case-control study was conducted on the Han population of northeast China.

Methods

Six polymorphic sites (V4, T+1, T2, T1, S1, and Q-1) were genotyped in 128 patients with AR, 181 patients with AS, and 151 healthy controls (CTR). Genotypes were determined by the polymerase chain restriction fragment length polymorphism (PCR-RFLP) method. Data were analyzed using the chi-square test with Haploview software.

Results

The single nucleotide polymorphisms (SNPs), V4 G/C, T+1 A/G, and T1 G/A, of the ADAM33 gene may be the causal variants in AR, whereas ADAM33 V4 G/C, T2 A/G, T1 G/A, and Q-1A/G may participate in the susceptibility of AS.

Conclusion

These results suggest that polymorphisms of the ADAM33 gene may modify individual susceptibility to AR and AS in a Chinese Han population.

Association of ADAM33 gene polymorphisms with adult concomitant allergic rhinitis and asthma in Chinese Han population

Allergic Rhinitis (AR) and allergic asthma (AS) are very common diseases involving genetic and environmental factors. Most patients with asthma also have rhinitis, which suggests the concept of 'one airway, one disease'. A disintegrin and metalloproteinase 33 (ADAM33) was discovered as the first asthma-susceptible gene by positional cloning. To evaluate the potential influences of ADAM33 gene polymorphisms on concomitant allergic rhinitis and asthma (ARA), a case-control study was conducted in Han population of Northeast China. Six polymorphic sites (V4, T + 1, T2, T1, S1 and Q - 1) were genotyped in 135 ARA patients and 151 controls (CTR). Genotypes were determined by the polymerase chain restriction fragment length polymorphism (PCR-RFLP) method. Data was analyzed using the Chisquaretest and Haploview software. The SNPs (V4 G/C, T2 A/G, T1 G/A, and Q - 1A/G) of the ADAM33 gene may be the causal variants in ARA disease.

Modeling the impact of genetic screening technologies on healthcare: theoretical model for asthma in children

BACKGROUND AND OBJECTIVE

This study focuses on the potential impact of genetic screening technologies on healthcare. Genetic screening for asthma in children was chosen as a case study to explore the cost effectiveness of applying early genetic screening to infants, and preventive treatment to the population at risk. Early intervention could prevent progression and facilitate clinical management of the disease. From the elite group of genetic markers that have been associated with asthma-related phenotypes, ADAM33 was the first published candidate gene detected by a positional cloning approach, marking the entry of asthma research into the genomic era. The model was, therefore, initially set for an ex ante analysis of the cost effectiveness of applying the preventive program to an infant population at risk, i.e. infants presenting wheezing episodes during the first year of life, and the ADAM33 ST+7 genetic marker, with the idea of expanding to further markers and their combinations lat a later date.

METHODS

In accordance with the US National Heart, Lung, and Blood Institute, four categories of asthma were considered. A Markov model was constructed, consisting of six mutually exclusive disease states (including healthy and dead states) with a simulation horizon of 100 years and a cycle length of 1 year. We define a scenario where early genetic screening was applied to infants presenting wheezing episodes during the first year of life and a preventive treatment to those children within this group who tested positive for selected ADAM33 polymorphism (ST+7). The cost-effectiveness analysis was performed from the third-party payer and patient perspective after year 6. We applied our model to a hypothetical cohort of 100 European infants.

RESULTS

The number of quality-adjusted life-years (QALYs) gained during the 6 years was 1.483, and the incremental cost-effectiveness ratio per QALY gained was euro 10,100/QALY. A sensitivity analysis was carried out that varied the discount rate and cost of genetic testing, and considered two different transition matrices for the preventive program. Three main conclusions were drawn from the sensitivity analysis. Firstly, if the discount rate for both cost and health outcomes is increased by 2%, the cost effectiveness of the preventive program does not vary significantly. Discounting costs and benefits at 5%, the preventive program appears cost effective (euro 11,100/QALY). Secondly, if the cost of genetic testing is increased to euro 100, the cost effectiveness of the preventive program remains within the limits of cost effectiveness. Thirdly, the cost of genetic screening, together with transition probabilities between health states, will determine the cost effectiveness of applying a preventive program based on genetic information.

CONCLUSIONS

Preventive treatment based on an early genetic screening of those children who present wheezing episodes during the first year of life, with treatment applied to those who test positive for the asthma-associated genetic marker ADAM33 ST+7, is theoretically cost effective. The model is a valuable tool for the ex ante assessment of the cost effectiveness of preventive schemes based on genetic screening. The value of modeling prior to clinical trials lies in informing study design and setting priorities for future research.

Comprehensive testing of positionally cloned asthma genes in two populations

RATIONALE

Replication of gene-disease associations has become a requirement in complex trait genetics.

OBJECTIVES

In studies of childhood asthma from two different ethnic groups, we attempted to replicate associations with five potential asthma susceptibility genes previously identified by positional cloning.

METHODS

We analyzed two family-based samples ascertained through an asthmatic proband: 497 European-American children from the Childhood Asthma Management Program and 439 Hispanic children from the Central Valley of Costa Rica. We genotyped 98 linkage disequilibrium-tagging single-nucleotide polymorphisms (SNPs) in five genes: ADAM33, DPP10, GPR154 (HUGO name: NPSR1), HLA-G, and the PHF11 locus (includes genes SETDB2 and RCBTB1). SNPs were tested for association with asthma and two intermediate phenotypes: airway hyperresponsiveness and total serum immunoglobulin E levels.

MEASUREMENTS AND MAIN RESULTS

Despite differing ancestries, linkage disequilibrium patterns were similar in both cohorts. Of the five evaluated genes, SNP-level replication was found only for GPR154 (NPSR1). In this gene, three SNPs were associated with asthma in both cohorts, although the opposite alleles were associated in either study. Weak evidence for locus-level replication with asthma was found in the PHF11 locus, although there was no overlap in the associated SNP across the two cohorts. No consistent associations were observed for the three other genes.

CONCLUSIONS

These results provide some further support for the role of genetic variation in GPR154 (NPSR1) and PHF11 in asthma susceptibility and also highlight the challenges of replicating genetic associations in complex traits such as asthma, even for genes identified by linkage analysis.

Mechanistic role of a disease-associated genetic variant within the ADAM33 asthma susceptibility gene

BACKGROUND

ADAM33 has been identified as an asthma-associated gene in an out-bred population. Genetic studies suggested that the functional role of this metalloprotease was in airway remodeling. However, the mechanistic roles of the disease-associated SNPs have yet to be elucidated especially in the context of the pathophysiology of asthma. One disease-associated SNP, BC+1, which resides in intron BC toward the 5' end of ADAM33, is highly associated with the disease.

METHODS

The region surrounding this genetic variant was cloned into a model system to determine if there is a regulatory element within this intron that influences transcription.

RESULTS

The BC+1 protective allele did not impose any affect on the transcription of the reporter gene. However, the at-risk allele enforced such a repressive affect on the promoter that no protein product from the reporter gene was detected. These results indicated that there exists within intron BC a regulatory element that acts as a repressor for gene expression. Moreover, since SNP BC+1 is a common genetic variant, this region may interact with other undefined regulatory elements within ADAM33 to provide a rheostat effect, which modulates pre-mRNA processing. Thus, SNP BC+1 may have an important role in the modulation of ADAM33 gene expression.

CONCLUSION

These data provide for the first time a functional role for a disease-associated SNP in ADAM33 and begin to shed light on the deregulation of this gene in the pathophysiology of asthma.

DNA sequence variations of metalloproteinases: their role in asthma and COPD

Asthma and chronic obstructive pulmonary disease (COPD) are complex genetic diseases that cause considerable morbidity and mortality worldwide. Genetic variability interacting with environmental and ethnic factors is presumed to cause tobacco smoke susceptibility and to influence asthma severity. A disintegrin and metalloproteinase 33 (ADAM33) and matrix metalloproteinase-9 (MMP9) appear to have important roles in asthma and COPD pathogenesis. ADAM33 and MMP9 genetic alterations could possibly contribute to the establishment and progression of these multifactorial diseases, although their association with the clinical phenotypes has not yet been elucidated. However, the occurrence of these alterations does not always result in clear disease, implying that either they are an epiphenomenon or they are in proximity to the true causative alteration. This review summarises the most recent literature dealing with the genetic variations of metalloproteinases and outlines their potential pathogenetic outcome.

Increased expression of ADAM33 and ADAM8 with disease progression in asthma

BACKGROUND

ADAM33, a disintegrin and metalloproteinase 33 gene, has been identified as a risk factor for asthma and bronchial hyperresponsiveness and has been postulated as a gene for airway remodeling. ADAM8 is strongly induced by allergens and T(H)2 cytokines in the lung in experimental asthma.

OBJECTIVES

To assess the importance of these genes in asthma pathogenesis and to investigate whether expression relates to disease severity or deterioration in lung function, we measured the mRNA and protein expression of both genes in bronchial biopsies of subjects with asthma and control subjects.

METHODS

RNA was extracted from frozen endobronchial biopsies of mild, moderate, and severe adults with asthma and controls. Subjects with moderate and severe asthma were taking corticosteroids. The mRNA transcript of both genes was measured by real time RT-PCR using specific primers. Protein expression was examined by immunohistochemistry on paraffin sections.

RESULTS

ADAM33 mRNA expression was significantly higher in both moderate and severe asthma compared with mild asthma (P < .05) and controls. Immunostaining for ADAM33 was increased in the epithelium, submucosal cells, and smooth muscle in severe asthma compared with mild disease and controls. ADAM8 mRNA expression was significantly increased in all asthma groups compared with controls. Increased inflammatory cells stained positive for ADAM8 in both moderate (P < .05) and severe asthma (P < .005) compared with mild disease.

CONCLUSIONS

These results demonstrate increased expression of both ADAM genes as asthma severity increases.

CLINICAL IMPLICATIONS

These genes may contribute to the remodeling process that occurs with asthma progression and may have implications for future treatment in severe disease.

ADAM33 polymorphisms are associated with aspirin-intolerant asthma in the Japanese population

Multiple single nucleotide polymorphisms (SNPs) within ADAM33 have been reported to be associated with asthma and bronchial hyper-responsiveness in Caucasian populations. We examined whether these SNPs contribute to a predisposition to asthma, especially aspirin-intolerant asthma (AIA), in the Japanese population. Ten polymorphic sites (ST+4, ST+7, T1, T2, T+1, V-3, V-2, V-1, V4, V5) were genotyped in 102 AIA patients, 282 aspirin-tolerant asthma (ATA) patients and 120 control (CTR) subjects by direct sequencing. Haplotype frequencies were estimated by the expectation-maximization method. Differences in allele and haplotype frequencies among phenotypes were analyzed by the chi-square and permutation tests. ST+7, V-1 and V5 sites in the AIA group were significantly different from those in the ATA group (P=0.034-0.004) and from those in the CTR group (P=0.019-0.002). Haplotypes at three sites (ST+7, V-1, and V5) were significantly different in frequency between the AIA and ATA (P=0.008) or CTR (P=0.001) groups. Sequence variations in ADAM33 are likely to correlate with susceptibility to AIA in the Japanese population.