The K469E polymorphism of the ICAM-1 gene is a risk factor for peripheral arterial occlusive disease

Systematic review and meta-analysis of the genetics of peripheral arterial disease

Background

Peripheral artery disease (PAD) impacts more than 200 million people worldwide. The understanding of the genetics of the disease and its clinical implications continue to evolve. This systematic review provides a comprehensive summary of all DNA variants that have been studied in association with the diagnosis and progression of PAD, with a meta-analysis of the ones replicated in the literature.

Methods

A systematic review of all studies examining DNA variants associated with the diagnosis and progression of PAD was performed. Candidate gene and genome-wide association studies (GWAS) were included. A meta-analysis of 13 variants derived from earlier smaller candidate gene studies of the diagnosis of PAD was performed. The literature on the progression of PAD was limited, and a meta-analysis was not feasible because of the heterogeneity in the criteria used to characterize it.

Results

A total of 231 DNA variants in 112 papers were studied for the association with the diagnosis of PAD. There were significant variations in the definition of PAD and the selection of controls in the various studies. GWAS have established 19 variants associated with the diagnosis of PAD that were replicated in several large patient cohorts. Only variants in intercellular adhesion molecule-1 (rs5498), IL-6 (rs1800795), and hepatic lipase (rs2070895) showed significant association with the diagnosis of PAD. However, these variants were not noted in the published GWAS.

Conclusions

Genetic research in the diagnosis of PAD has significant heterogeneity, but recent GWAS have demonstrated variants consistently associated with the disease. More research focusing on the progression of PAD is needed to identify patients at risk of adverse events and develop strategies that would improve their outcomes.

Unveiling the Genetic Footprint: Exploring Somatic Mutations in Peripheral Arterial Disease Progression

Peripheral arterial diseases (PADs) are complex cardiovascular conditions influenced by environmental factors and somatic mutations in multiple genes involved in hematopoiesis and inflammation. While traditional risk factors, such as smoking, hypercholesterolemia, and hypertension, have been extensively studied, the role of somatic mutations in PAD progression remains underexplored. The present article intends to provide a comprehensive commentary of the molecular mechanisms, genetic landscape, prognostic significance, and clinical implications of somatic mutations in PADs. The expansion of clonal hematopoiesis of indeterminate potential (CHIP) clones in the circulating blood, named clonal hematopoiesis (CH), leads to the infiltration of these clones into atherosclerotic plaques and the production of inflammatory cytokines, increasing the risk of cardiovascular diseases, including PADs. Furthermore, recent experimental evidence has demonstrated the involvement of somatically mutated TP53 genes with a high variant allele frequency (VAF) in PAD development and prognosis. This review delves into the relationship between CH and PADs, elucidating the prevalence, impact, and underlying mechanisms of this association. This understanding paves the way for novel therapeutic approaches targeting CHIP to promote tissue regeneration and improve outcomes in PAD patients. It emphasizes the need for further research to fully unravel the genetic footprint of the disease and highlights potential clinical implications. The findings presented in this article lay the foundation for personalized medicine approaches and open avenues for the development of targeted therapies based on somatic mutation profiling.

Associations between the rs5498 (A > G) and rs281432 (C > G) polymorphisms of the ICAM1 gene and atherosclerotic cardiovascular disease risk, including hypercholesterolemia

Background

Atherosclerotic cardiovascular disease (ASCVD) originates from complex risk factors, including age, gender, dyslipidemia, obesity, race, genetic and genetic variation. ICAM1 gene polymorphisms are a significant risk factor for ASCVD. However, the impact of the rs5498 and rs281432 polymorphisms on the prevalence of hypercholesterolemia (HCL) has not been reported. Therefore, we determine the relationships between single nucleotide polymorphisms (SNPs), including rs5498 and rs281432 on Intercellular adhesion molecule 1 gene (ICAM1) and ASCVD susceptibility in patients with HCL.

Methods

The clinical characteristics of 278 participants were assessed, and classified to groups having HCL and without HCL. ICAM1 SNPs genotyping was performed by DNA sequencing, and ICAM1 expression was measured using real-time PCR.

Results

Positive dominant model rs5498 participants had twice the risk of HCL (95% confidence interval (CI): [1.24-3.23], P = 0.005). The frequency of the G allele in rs5498 was 1.69 times higher in participants with HCL than in controls (95% CI [1.15-2.47], P = 0.007). Participants with the rs5498 AG or GG variants and high ICAM1 mRNA expression (≥3.12) had 2.49 times the risk (95% CI [1.42-4.38], P = 0.001), and those with a high LDL-C concentration (≥3.36 mmol/L) had 2.09 times the risk (95% CI [1.19-3.66], P = 0.010) of developing ASCVD compared with those with low ICAM1 mRNA and LDL-C levels. Interestingly, participants carrying the rs5498 AG or GG variants who had tachycardia (resting heart rates (RHRs) >100 beats/min) had a 5.02-times higher risk than those with a lower RHR (95% CI [1.35-18.63], P = 0.016).

Conclusions

It may consider the G allele in ICAM1 rs5498 is associated with a higher risk of ASCVD in Thai people with HCL, and is also positively associated with ICAM1 mRNA expression, LDL-C concentration, and RHR.

Association between K469E polymorphism of ICAM‐1 gene and susceptibility of ischemic stroke: An updated meta‐analysis

Background

The intercellular adhesion molecule‐1 (ICAM‐1)/leukocyte function associated antigen‐1 (LFA‐1) adhesion system regulates leukocyte interactions, migration, and adhesion, and appears to play an important role in atherosclerosis and thrombosis. Therefore, single nucleotide polymorphisms (SNPs) of the ICAM‐1 gene may strongly influence the expression and biological activity of ICAM‐1 and play a potentially important role in the pathogenesis of ischemic stroke. In the current meta‐analysis, we investigated the relationship between the ICAM‐1 gene K469E SNP and the risk of ischemic stroke.

Methods

Two investigators independently searched PubMed, Web of Science, Google Scholar, WANFANG, China National Knowledge Infrastructure (CNKI) and J‐STAGE for studies published from January 2000 to February 2019 without language restriction. The association of K469E polymorphism and ischemic stroke in three genetic models (allelic, recessive, and dominant) were evaluated using Pooled odds ratios (ORs) with 95% confidence intervals (CIs).

Results

Our study included 20 studies from four continents and four different countries, including 3,137 cases and 15,382 controls. Meta‐analysis results did not show a significant association between K469E polymorphism of ICAM‐1 gene and ischemic stroke when assuming allelic model (OR: 1.12; 95% CI: 0.8 to 1.55; p = 0.51; I² = 93%) or recessive model (OR: 1.28; 95% CI: 0.89 to 1.84; p = 0.18; I² = 82%) or dominant model (OR: 1.20; 95% CI: 0.92 to 1.56; p = 0.17; I² = 85%). However, in all three genetic models, subgroup analysis revealed that the K469E polymorphism of the ICAM‐1 gene is associated with ischemic stroke in the Caucasian population.

Conclusion

K469E polymorphism of ICAM‐1 gene might be a risk factor for ischemic stroke in Caucasians, which suggested that K469E polymorphism might help in early identification of those at risk and help in primary prevention of ischemic stroke.

Association between the ICAM-1 gene polymorphism and coronary heart disease risk: a meta-analysis

Coronary heart disease (CHD) is a complex polygenic disease in which gene-environment interactions play a critical role in disease onset and progression. The Intercellular adhesion molecule 1 (ICAM-1) gene E469K polymorphism is one of the most commonly studied polymorphisms in this gene because of its association with CHD risks, but results were conflicting. The PubMed, Embase, and China National Knowledge Infrastructure databases were searched for case–control studies published up to November 2018. Pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated to assess the association. Eleven eligible studies, comprising 3435 cases and 3199 controls, were included in the meta-analysis. The pooled result showed that the ICAM-1 gene E469K polymorphism was significantly associated with an increased risk of CHD (OR = 1.20, 95% CI = 1.11–1.29, for the allele K versus allele E; OR = 1.66, 95% CI = 1.43–1.92, for the K allele carriers versus EE). Subgroup analysis supported the results in the Chinese populations and in the Caucasian populations. This meta-analysis suggests that the ICAM-1 gene K469E polymorphism is associated with CHD risk and the K allele is a more significant risk factor for developing CHD amongst Chinese and Caucasians populations.

ICAM-1 gene rs5498 polymorphism decreases the risk of coronary artery disease

BACKGROUND

Many studies investigated the association between intercellular adhesion molecule 1 (ICAM-1) gene rs5498 polymorphism and the risk of coronary artery disease (CAD). However, the results were inconsistent.

METHODS

To clarify convincing association, we conducted a comprehensive meta-analysis by searching in PubMed, Embase, Web of sciences, Sciences citation index, Google scholar, Cochrane Library, and the CNKI databases. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated.

RESULTS

A total of 29 case-control studies with 5,494 cases and 6,364 controls for rs5498 polymorphism were included. The studied populations of this meta-analysis included Caucasians and Asians. Meta-analysis showed that rs5498 polymorphism was associated with the decreased risk of CAD. Stratification analysis of ethnicity found that rs5498 polymorphism decreased the risk of CAD among Caucasians, but not among Asians. Stratification by type of CAD revealed that ICAM-1 gene rs5498 polymorphism was also correlated with the decreased risk of myocardial infarction (MI).

CONCLUSION

In conclusion, this meta-analysis indicates that ICAM-1 gene rs5498 polymorphism decreases the risk of CAD.

Peripheral Arterial Disease Genetics: Progress to Date and Challenges Ahead

PURPOSE OF REVIEW

In this paper, we review the progress made thus far in research related to the genetics of peripheral arterial disease (PAD) by detailing efforts to date in heritability, linkage analyses, and candidate gene studies. We further summarize more contemporary genome-wide association studies (GWAS) and epigenetic studies of PAD. Finally, we review current challenges and future avenues of advanced research in PAD genetics including whole genome sequencing studies.

RECENT FINDINGS

Studies have estimated the heritability of PAD to be moderate, though the contribution to this heritability that is independent of traditional cardiovascular risk factors remains unclear. Recent efforts have identified SNPs associated with PAD in GWAS analyses, but these have yet to be replicated in independent studies. Much remains to be discovered in the field of PAD genetics. An improved understanding of the genetic foundation for PAD will allow for earlier diagnosis of disease and a more complete pathophysiological understanding of the mechanisms of the disease leading to novel therapeutic interventions. Future avenues for success will likely arise from very large-scale GWAS, whole genome sequencing, and epigenetic studies involving very well-characterized cohorts.

Correlations of ICAM-1 gene polymorphisms with susceptibility and multidrug resistance in colorectal cancer in a Chinese population

BACKGROUND

Colorectal cancer (CRC) is a malignant gastrointestinal tumor with a high mortality rate, including both colon and rectal cancer. In order to provide clinical guidance for the treatment of CRC, this study is conducted to investigate the correlations of intercellular adhesion molecule 1 (ICAM-1) gene polymorphisms with susceptibility and multidrug resistance (MDR) of colorectal cancer (CRC).

METHODS

A total of 195 patients with CRC were selected as the observation group and 188 healthy people enrolled as the control group. Polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) was used to test ICAM-1 A13848G and K469E polymorphisms. The expressions of MDR-associated protein topoisomerase II (Topo II) and P-glycoprotein (P-gp) in CRC tissues were detected by immunohistochemistry. The analysis on association of clinical indexes of CRC patients with ICAM-1 gene polymorphisms was performed.

RESULTS

The frequencies of KK genotype and K allele of K469E in the observation group were significantly higher than that in the control group. KE + EE genotype and E allele might be protective factors for CRC. The distribution of genotypes, K469E KK and KE+EE, was highly correlated with histologic grade of tumor differentiation. Compared with adjacent normal tissues, positive rates of Topo II and P-gp expression were significantly increased in CRC tissues. Topo II expression in CRC patients was positively associated with lymph node metastasis and depth of tumor invasion, whereas P-gp expression was only associated with depth of tumor invasion. Higher positive rates of Topo II and P-gp expression were observed in ICAM-1 K469E KK genotype carriers, indicating that ICAM-1 K469E KK genotype might be related to MDR in CRC.

CONCLUSION

These findings in the current study suggested that ICAM-1 K469E polymorphism is highly correlated with susceptibility and MDR in CRC.

Polymorphism rs5498 of the ICAM-1 gene affects the progression of carotid atherosclerosis in patients with type 2 diabetes mellitus

Background

Adhesion molecules are involved in the development of atherosclerosis. An increased level of the ICAM 1 molecule is associated with numerous inflammatory diseases including atherosclerosis of carotid arteries. The rs5498 (K469E) polymorphism of the ICAM-1 gene leads to an increase in the level of serum ICAM. We investigated the association between the rs5498 (K469E) polymorphism of the ICAM-1 gene and the progression of carotid atherosclerosis in subjects with type 2 diabetes mellitus (T2DM).

Methods

The study included 595 patients with T2DM and 200 subjects in the control group without T2DM. The control examination was made 3.8 years after the initial examination. Indicators of atherosclerosis (carotid intima-media thickness (CIMT), total plaque sum and sum of the plaques thickness) were detected by ultrasound examination. Genetic analyses of the polymorphism rs5498 of the ICAM-1 gene were made by RT-PCR.

Results

The distribution of genotypes and frequencies of rs5498 polymorphism was not significantly different between the group with type 2 diabetes ( T2DM) and the control group. Genotype EE K469E polymorphism is associated with a statistically significant annual plaques growth.

Conclusion

The EE genotype of the rs5498 of the ICAM-1 gene was associated with a more rapid progression of carotid atherosclerosis in patients with T2DM in comparison with other genotypes.

Impact of Intercellular Adhesion Molecule-1 Genetic Polymorphisms on Coronary Artery Disease Susceptibility in Taiwanese Subjects

The principal pathogenesis of coronary artery disease (CAD) is coronary artery atherosclerosis, a chronic inflammatory disease of the vessel walls of the coronary artery. Intercellular adhesion molecule-1 (ICAM-1) displays an important role in the development of the inflammation reaction and atherosclerosis. Few studies report the association of ICAM-1 genetic polymorphisms with CAD in Taiwanese subjects. Therefore, we conducted a study to associate the single nucleotide polymorphisms (SNPs) of ICAM-1, rs5491, rs5498, rs281432 and rs3093030 with CAD. Five hundred and twenty-five male and female subjects, who received elective coronary angiography in Taiwan Chung Shan Medical University Hospital, were recruited to determine four ICAM-1 SNPs by real time-polymerase chain reaction and genotyping. The relationships among ICAM-1 SNPs, haplotypes, demographic and characteristics and CAD were analyzed. This study showed that rs281432 (C8823G) was the only ICAM-1 SNP which affect the development of CAD. Multivariate analysis revealed that ICAM-1 SNP rs281432 CC/CG [p=0.016; odds ratio (OR): 2.56, 95% confidence interval (CI): 1.19-5.56], male gender (p=0.018; OR: 1.66, 95% CI: 1.09-2.51), aspirin use in the past 7 days (p=0.001; OR: 2.05, 95% CI: 1.33-3.14), hypertension (p<0.001; OR: 2.15, 95% CI: 1.42-3.25), serum cardiac troponin I elevation (p<0.001; OR: 2.14, 95% CI: 1.47-3.24) and severe angina in recent 24 hours (p=0.001; OR: 1.97, 95% CI: 1.31- 2.95) increase the risk of CAD. In conclusion, ICAM-1 SNP rs281432 is an independent factor to predict the development of CAD. ICAM-1 SNP rs281432 homozygotic mutant GG can reduce the susceptibility to the CAD in Taiwanese subjects.

Intercellular adhesion molecule-1 K469E polymorphism and risk of coronary artery disease: a meta-analysis

Background

Intercellular adhesion molecule-1 (ICAM-1) K469E polymorphism has been implicated in susceptibility to coronary artery disease (CAD). Several studies investigated the association of this polymorphism with CAD in different populations but the results were contradictory. A meta-analysis was conducted to assess the association between ICAM-1 K469E polymorphism and CAD susceptibility.

Material/Methods

Databases including PubMed, EMBASE, China National Knowledge Infrastructure (CNKI), and Weipu Database were searched to find relevant studies. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of associations. A random-effects model was used.

Results

Fifteen case-control studies including 3088 cases and 3466 controls were included. Overall, a significant association between ICAM-1 K469E polymorphism and CAD was observed in the dominant model (OR=1.80; 95% CI 1.62–2.01; P<0.00001; P_{heterogeneity}=0.40). In subgroup analysis by ethnicity, a significant association was found among Asians (OR=1.92; 95% CI 1.51–2.43; P<0.00001; P_{heterogeneity}=0.98) and among Caucasians (OR=1.64; 95% CI 1.30–2.08; P<0.0001; P_{heterogeneity}=0.04). In the subgroup analysis by age, a significant association was found among young patients (OR=1.46; 95% CI 1.10–1.93; P=0.008; P_{heterogeneity}=0.21) and old patients (OR=1.92; 95% CI 1.75–2.10; P<0.00001; P_{heterogeneity}=0.99).

Conclusions

Results of this meta-analysis suggest that ICAM-1 K469E polymorphism confers a risk factor of CAD.

Association of intercellular adhesion molecule‑1 gene polymorphism with coronary heart disease

Intercellular adhesion molecule‑1 (ICAM‑1) is an important adhesion molecule that has a crucial role in lymphocyte migration and atherosclerosis pathogenesis activation. The aim of the present study was to explore the association between the rs5498 polymorphism of the ICAM‑1 gene and coronary heart disease (CHD). The rs5498 polymorphism of the ICAM‑1 gene was detected using polymerase chain reaction‑restriction fragment length polymorphism in 674 patients with CHD and 779 control subjects. The results showed that the frequency of the G allele was significantly higher in patients with CHD than that in controls (29.1 vs. 23.3%; P<0.001). The frequency of the AG+GG genotypes was higher in patients with CHD than that in controls (49.7 vs. 40.8%; P=0.001). Multiple logistic regression analysis showed that AG+GG was an independent risk factor for CHD (odds ratio, 1.919; 95% confidence intervals, 1.471‑2.503; P<0.001). For males, the frequencies of the G allele and AG+GG genotype were also higher in patients with CHD than those in control subjects (frequency of G allele, 29.9 vs. 22.7%; P<0.001; frequency of AG+GG genotype, 50.6 vs. 40.3%; P=0.001). For females, no significant differences in genotype or allele distribution were observed between the two groups. In conclusion, it was demonstrated in the present study that the rs5498 polymorphism of the ICAM‑1 gene was associated with CHD in males. Males with the G allele (AG and GG genotype) may therefore have a higher risk for CHD than those with the AA genotype.

ICAM-1 and SRD5A1 gene polymorphisms in symptomatic peripheral artery disease

The genotype distribution of two gene polymorphisms, previously associated with peripheral artery disease (PAD), has been evaluated in a population of diabetic (DPAD) and non-diabetic (NDPAD) patients affected by symptomatic PAD (stages II-IV). A decreased frequency of the AA genotype of rs5498 (ICAM-1) was observed in the PAD subjects compared to controls but this result did not reach statistical significance (p=0.06 by chi-squared test). On the contrary, a significant increase in the frequency of the GG homozygous genotype of rs248793 (SRD5A1) was observed in the PAD patient group in comparison to controls (p=0.01). These data confirm that the GG genotype of rs248793 in the SRD5A1 gene is significantly associated with symptomatic PAD and show a trend towards a stronger association with the non-diabetic status.

Association of intercellular adhesion molecular-1 gene polymorphism in ischemic stroke patients

BACKGROUND

Ischemic stroke (IS) is a prevalent disease causing a body disability, the third leading cause of death in Taiwan. It shows that the level of intercellular adhesion molecular-1 (ICAM-1) in IS patients is higher than control subjects.

OBJECTIVE

This study is to investigate the possible association of ICAM-1 (G1548A) polymorphism in IS patients.

MATERIALS AND METHODS

A total of 646 subjects were enrolled in this study, including 312 IS patients, and 334 controls without a history of symptomatic IS. The ICAM-1 (G1548A) polymorphism was analyzed by polymerase chain reaction and restriction fragment length polymorphism. Clinical factors were also determined.

RESULTS

The frequencies of the ICAM-1 (G1548A) polymorphism for G/G, G/A, and A/A were 74.8%, 23.9%, and 0.3%, respectively, in healthy controls, and 62.8%, 32.1%, and 5.1%, respectively, in patients. The frequency of the ICAM-1 (G1548A) A allele (21.2% versus 13.2%, respectively; P = 0.007) and the carriers of the ICAM-1 (G1548A) A allele (37.2% versus 25.2%; P = 0.019, OR 1.76, 95% CI 1.1-2.83) are great in IS patients compared with healthy controls. There is a higher risk of IS associated with homozygosity for the ICAM-1 (G1548A) A allele (AA genotype) compared with the control population (5.1% vs. 0.3%, respectively, P = 0.04; OR 5.1, 95% CI 1.19-21.66). We also observed both hypertension and diabetes has shown a positive association with IS.

CONCLUSIONS

The ICAM-1 (G1548A) polymorphism was associated with independent risk factor for the development of IS.

Genetic variations in E-selectin and ICAM-1: relation to atherosclerosis

Background

This study aimed to investigate the association of both intercellular adhesion molecule-1 (ICAM-1) and endothelial cell adhesion molecule (E-selectin) polymorphisms using PCR technique and their role in the pathogenesis of atherosclerosis.

Material/Methods

The study enrolled 285 individuals, classified into 4 groups: 63 cerebrovascular atherosclerotic patients, 75 cardiovascular patients, 72 peripheral atherosclerotic patients and 75 normal healthy individuals.

Results

The frequency of the mutant AC genotype of E-selectin in peripheral, cerebral and cardiovascular atherosclerotic patients was significantly higher than in control subjects (29.17%, 28.53% and 28% vs. 8%, respectively). However, no significant difference was observed in the frequency of mutant CC allele between all atherosclerotic patients and control groups. The frequency of the mutant EE homozygotes of ICAM-1 in peripheral, cerebral and cardiovascular atherosclerotic patients was significantly higher compared to controls (45.8%, 42.9% and 36% vs. 12%, respectively). The frequency of EK of ICAM-1 showed no significant difference between atherosclerotic patients and the control group. The frequency of the mutant E allele of ICAM-1 was significantly higher in peripheral, cerebral and cardiovascular patients compared to controls (58.3%, 54.8% and 54% vs. 26%, respectively).

Conclusions

Ser 128Arg of E-selectin and the K469E of ICAM-1 polymorphisms may be involved in predisposition to atherosclerosis.

The intercellular adhesion molecule-1 (ICAM-1) gene polymorphism K469E in end-stage renal disease patients with cardiovascular disease

The intercellular adhesion molecule-1 (ICAM-1) mediates interaction of activated endothelial cells with leukocytes. It plays an important role in the pathogenesis of atherosclerosis. A functionally important polymorphism of the ICAM-1 gene, K469E, has been described. We investigated whether this polymorphism influences the risk of CVD in end-stage renal disease (ESRD) patients. The groups of 1016 ESRD patients and 824 healthy individuals were genotyped by PCR and allele specific oligonucleotide technique. The T allele of the K469E polymorphism was significantly more frequent in ESRD CVD+ patients than CVD- and controls (OR 2.26, 95% CI 1.87-2.72 and 1.82, 95% CI 1.55-2.11, respectively). The TT genotype was also more frequent in CVD+ patients (OR 9.90, 95% CI 6.17-15.88 vs. CVD- subgroup). When patients were stratified according to clinical outcome of CVD, there was a tendency towards higher frequencies of the T allele and TT genotype in patients with myocardial infarction (OR for T allele 1, 57, 95% CI 1.12-2.18 vs. patients without MI). In the multivariate regression analysis the carrier status of T allele of K469E was an independent risk factor of susceptibility to CVD. Our data suggest that the ICAM-1 K469E polymorphism is associated with CVD in ESRD patients.

Intercellular adhesion molecule 1 gene K469E polymorphism is associated with coronary heart disease risk: a meta-analysis involving 12 studies

Coronary atherosclerosis is a leading cause of coronary heart disease (CHD). Atherosclerotic lesion is a complex polygenic disease in which gene-environment interactions play a critical role in disease onset and progression. The ICAM1 gene-E469K polymorphism has been reported to be associated with CHD, but results were conflicting. A systematic review and meta-analysis of the published studies were performed to gain a clearer understanding of this association. The PubMed, Embase, and CNKI databases were searched for case-control studies published up to August 2011. Data were extracted and pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated. Twelve eligible studies, comprising 2,157 cases and 1,952 controls, were included in the meta-analysis. The pooled result showed that the ICAM1 gene-E469K polymorphism was significantly associated with an increased risk of CHD (OR = 1.496, 95% CI = 1.363-1.642, for the allele K vs. allele E; OR = 1.919, 95% CI = 11.635-2.253, for the K allele carriers vs. EE). Subgroup analysis supported the results in the Asian populations and in the Caucasian populations. This meta-analysis suggests that the ICAM1 gene K469E polymorphism is associated with CHD risk and the K allele is a more significant risk factor for developing CHD among Asian and Caucasians populations.

Polymorphisms in the ICAM1 gene predict circulating soluble intercellular adhesion molecule-1(sICAM-1)

OBJECTIVE

Polymorphisms within the ICAM1 structural gene have been shown to influence circulating levels of soluble intercellular adhesion molecule-1 (sICAM-1) but their relation to atherosclerosis has not been clearly established. We sought to determine whether ICAM1 SNPs are associated with circulating sICAM-1 concentration, coronary artery calcium (CAC), and common and internal carotid intima medial thickness (IMT).

METHODS AND RESULTS

3550 black and white Coronary Artery Risk Development in Young Adults (CARDIA) Study subjects who participated in the year 15 and/or 20 examinations and were part of the Young Adult Longitudinal Study of Antioxidants (YALTA) ancillary study were included in this analysis. In whites, rs5498 was significantly associated with sICAM-1 (p<0.001) and each G-allele of rs5498 was associated with 5% higher sICAM-1 concentration. In blacks, each C-allele of rs5490 was associated with 6% higher sICAM-1 level; this SNP was in strong linkage disequilibrium with rs5491, a functional variant. Subclinical measurements of atherosclerosis in either year 15 or year 20 were not significantly related to ICAM1 SNPs.

CONCLUSIONS

In CARDIA, ICAM1 DNA segment variants were associated with sICAM-1 protein level including the novel finding that levels differ by the functional variant rs5491. However, ICAM1 SNPs were not strongly related to either IMT or CAC. Our findings in CARDIA suggest that ICAM1 variants are not major early contributors to subclinical atherosclerosis.

Intercellular adhesion molecule-1 gene polymorphisms in patients with familial mediterranean fever

Familial Mediterranean fever (FMF) is a disease of unknown etiology characterized by recurrent attacks of polyserositis and fever. Intercellular adhesion molecule-1 (ICAM-1) is known to contribute inflammatory conditions by regulating leukocyte localization at inflammatory sites. The aim of this study was to evaluate the probable association of ICAM-1 G/R 241 and ICAM-1 E/K 469 polymorphisms according to susceptibility with FMF. Sixty-seven FMF patients and 83 healthy volunteers were included in the study. Genomic DNA was extracted from EDTA-preserved whole blood of whole series of patients and controls, and genotyped by polymerase chain reaction (PCR) and allele-specific oligonucleotide techniques for ICAM-1 polymorphisms G/R at codon 241 and E/K at codon 469. The ICAM-1 241 genotype and allele frequencies of FMF patients and healthy volunteers were similar. The frequency of ICAM-1 K469 homozygosity was significantly lower in FMF patients than in the controls (32.8% vs 50.7% subsequently, p=0.03). Moreover, ICAM-1 E469 allele was more frequent in FMF patients than in controls (44.8% vs 32.3%, p:0.03). Our results showed that ICAM-1 469 gene polymorphism could contribute to the pathogenesis of FMF.

Peripheral artery disease and genetics: is there a cause-and-effect relationship?

Peripheral artery disease (PAD) is a major health problem worldwide, affecting millions of patients. Although cardiovascular risk factors, such as diabetes, tobacco use, hypertension, and hypercholesterolemia have been associated with the development of PAD, the possible existence of an inherited genetic predisposition to PAD has been investigated in numerous familial aggregation studies. A link between genetics and PAD may open new avenues for the prevention of this morbid and mortal disorder. This is an overview of the potential association between genetics and PAD.

Role of ICAM-1 and E-selectin gene polymorphisms in pathogenesis of PAOD in Egyptian patients

Background:

Intercellular adhesion molecule-1 (ICAM-1) and E-selectin have been shown to predict cardiovascular disease (CVD) such as myocardial infarction, stroke, and peripheral arterial occlusive disease (PAOD).

Methods:

Two mutations, S128R in E-selectin and K469E in ICAM-1, were investigated in 156 patients with PAOD and 100 control subjects using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis in an Egyptian population.

Results:

The distribution of E-selectin genotypes in patients affected by PAOD was 84.6% for the AA genotype and 15.4% for the AC genotype. In the control arm the distribution was 97% for the AA genotype and 3% for the AC genotype. There was a statistically significance difference in the distribution of the AC genotype in PAOD patients when compared with the control subjects. Additionally, the distribution of ICAM-1 genotypes in patients affected by PAOD was 30.8% with the EE, 48% with the EK, and 21.2% with the KK genotypes. The distribution of ICAM-1 genotypes in control subjects was 13% EE, 33% EK and 54% KK. The EE genotype was significantly more common in PAOD patients than in the controls.

Conclusion:

S128R and K469E polymorphisms were associated with increased risk in PAOD. Early detection of these polymorphic genes helps in early prophylaxis against PAOD.

A field synopsis and meta-analysis of genetic association studies in peripheral arterial disease: The CUMAGAS-PAD database

In an electronic search of the literature, the authors systematically retrieved all published studies that investigated genetic susceptibility to peripheral arterial disease (PAD). They created a comprehensive database of all eligible studies, collecting detailed genetic and bioinformatics data on each polymorphism. Data from eligible studies were synthesized using meta-analysis techniques. Gene variants were classified into distinct pathophysiologic pathways, and their potential involvement in PAD pathogenesis was determined. Forty-one publications that examined 44 gene polymorphisms were included. For 37 polymorphisms, the variant form had a functional effect. Twenty-three polymorphisms in 22 potential PAD candidate genes (F2, FGB, MTHFR, ITGB3, ACE, AGT, IL6, CCL2, ICAM1, SELE, MMP9, PPARG, MMP1, ADD1, P2RY12, LIPC, PLA2G7, SCARB1, MMP3, MTTP, LPA, CHRNA3) showed a significant association in individual studies. Eighty-eight percent of the studies had statistical power of less than 50%, and in 15 studies the genotype distribution in the control group did not conform to Hardy-Weinberg equilibrium. Data on 12 polymorphisms (F5 1691 G/A, MTHFR 677C/T, F2 20210 G/A, ITGB3 1565 T/C, ACE I/D, AGT 704C/T, AGT -6G/A, AGT 733C/T, IL6 -174 G/C, MMP9 -1562C/T, ICAM1 1462A/G, CHRNA3 831C/T) were synthesized, and a positive association was found for 3 (IL6 -174 G/C, ICAM1 1462A/G, CHRNA3 831C/T).

A candidate gene approach to genetic prognostic factors of IgA nephropathy--a result of Polymorphism REsearch to DIstinguish genetic factors Contributing To progression of IgA Nephropathy (PREDICT-IgAN)

BACKGROUND

Renal prognosis of IgA nephropathy (IgAN) is affected by environmental and genetic factors. Other studies demonstrated that some atherosclerotic disease-related genes were significantly associated with renal prognosis.

METHODS

The Polymorphism REsearch to DIstinguish genetic factors Contributing To progression of IgAN (PREDICT-IgAN) was a multicentre retrospective observational study to investigate associations between progression of IgAN (a 50% increase of serum creatinine level and slope of eGFR) and a hundred atherosclerotic disease-related gene polymorphisms, mainly single nucleotide polymorphisms (SNPs) in 320 IgAN patients who had more than a normal range of urinary protein (> or =0.25 g/day) at diagnosis.

RESULTS

During 8.3 +/- 4.2 years of a follow-up period, 83 patients (25.9%) developed progression. In log-rank tests, glycoprotein Ia GPIa C807T and G873A and intercellular adhesion molecule-1 ICAM-1 A1548G (K469E) were found to be significantly associated with progression even after adjustment for multiple comparisons by the method of Bonferroni (adjusted P = 0.0174, 0.0176 and 0.0430, respectively). In a multivariate Cox proportional-hazards model, GPIa 807TT (873CC) [versus 807TT, adjusted hazard ratio 2.05 (95% confidence interval 1.13-3.71)] and ICAM-1 1548GG [versus 1548AA, 2.55 (1.40-4.65)] were identified as independent genetic predictors of progression, along with conventional clinical prognostic factors such as eGFR, urinary protein and use of antihypertensives at diagnosis.

CONCLUSIONS

PREDICT-IgAN distinguished GPIa C807T/ G873A and ICAM-1 A1548G from multiple athero- sclerotic disease-related gene polymorphisms by their predictive indicator for progression of IgAN.

Interactions between rs5498 polymorphism in the ICAM1 gene and traditional risk factors influence susceptibility to coronary artery disease

Coronary artery disease (CAD) depends on multiple genetic and environmental factors. Adhesion molecules are markers of endothelium dysfunction. Intercellular adhesion molecule-1 (ICAM-1) interacts with leukocyte integrins and promotes atherosclerotic process at the surface of endothelial cells. The aim of the study was to assess the association between ICAM1 rs5498 polymorphism and CAD and to establish whether there are any interactions between this polymorphism and traditional risk factors in determining the risk of CAD. We studied 191 cases with angiographically documented CAD and 203 controls with no signs of cardiovascular diseases. The ICAM1 polymorphism was genotyped using PCR-RFLP method. Data were analyzed with the STATISTICA 7.1 and EpiInfo 6 softwares. We did not observe significant differences in the distribution of genotypes and alleles of rs5498 between cases and controls. We only found a tendency to a higher prevalence of G allele carriers (AG + GG) in patients compared to controls (68 vs. 64%, P = 0.399). A synergistic effect of G allele carrier-state and smoking that had influenced the risk of CAD [synergy index multiplicative (SIM = 2.09)] was observed. Smoking carriers of G allele compared to non-smoking AA were more prevalent in CAD group (39.8%) than among controls (13.3%, P < 0.0001, OR 4.81). Moreover, there was also a synergistic effect between G allele carrier-state and an elevated level of triacylglycerols (TG) (SIM = 1.28) increasing the risk of CAD. There is a synergistic interaction between rs5498 genotype and smoking that increases the risk of CAD.

K469E polymorphism of the intracellular adhesion molecule 1 gene is associated with proliferative diabetic retinopathy in Caucasians with type 2 diabetes

BACKGROUND

In proliferative diabetic retinopathy (PDR) increased levels of cytokines, inflammatory cells and angiogenic factors are present.These factors increase the expression of cellular adhesion molecules (CAMs)The objective of this study was to investigate the association between the polymorphisms of the ICAM-1 gene (K469E, G241A) and the development of PDR among patients with type 2 diabetes in the Slovenian population (Caucasians).

METHODS

For the purpose, 195 subjects with type 2 diabetes with PDR were compared with 143 subjects with type 2 diabetes of duration of more than 10 years who had no clinical signs of diabetic retinopathy. We analysed serum ICAM levels in 54 subjects with type 2 diabetes and 25 subjects without diabetes.

RESULTS

A significantly higher frequency of the EE genotype of the K469E polymorphism of the ICAM-1 was found in the patients with PDR compared with those without diabetic retinopathy (OR = 2.0, 95% confidence interval [CI] = 1.1-3.5; P = 0.013), whereas the G241A polymorphism of the ICAM-1 gene failed to yield an association with PDR. Moreover, significantly higher sICAM-1 serum levels were demonstrated in diabetics with the EE genotype compared with those with the other (EK + KK) genotypes (918 +/-104 vs. 664 +/-209 microg/L; P = 0.001). The G241A polymorphism of the ICAM-1 gene, on the hand, failed to affect sICAM-1 serum levels in diabetics.

CONCLUSIONS

We may conclude that the EE genotype of the K469E polymorphism of the ICAM-1 might be a risk factor for PDR in the Slovenian population (Caucasians) with type 2 diabetes.

Intercellular adhesion molecule-1 gene K469E polymorphism and ischemic stroke: a case-control study in a Chinese population

BACKGROUND

Intercellular adhesion molecule-1 (ICAM-1) was involved in the pathogenetic mechanisms responsible for ischemic stroke (IS). Population-based sample have revealed gene-gender interaction in blood pressure which is major risk for IS. We sought to evaluate whether ICAM-1 K469E polymorphism was involved in the causation of IS and whether it was different between female and male.

METHODS

A 1:1 case-control study was conducted. The K469E polymorphism of ICAM-1 gene were analyzed by polymerase chain reaction (PCR) and restriction enzyme analysis in Chinese patients with IS (n = 309) and elderly subjects without IS (n = 309).

RESULTS

ICAM-1 K469E polymorphism was significantly associated with IS. Interestingly, a further analysis stratified by sex found that there was significance between 469E genotypes and IS in female, but not in male. Multiple regression analysis revealed that ICAM-1 K469E polymorphism was still significantly associated with IS, compared with ICAM-1 KK genotype in all population (OR = 1.60, P = 0.030). Stratified by sex, EE combined EK was contributory factor to IS in female (OR = 3.03, P = 0.004), but not in male. After adjustment for confounding factors, the interaction between female and ICAM-1 EK/EE genotypes was found (OR = 3.54, P = 0.001).

CONCLUSIONS

It is suggested that the ICAM-1 469E allele may be important in the pathogenesis of ischemic stroke, especially in female but not in male.

Elevated serum levels of intercellular adhesion molecule ICAM-1 in Pseudoxanthoma elasticum

BACKGROUND

Pseudoxanthoma elasticum (PXE, OMIM 177850 and 264800) is a rare heritable disorder predominantly affecting the skin, the eyes and the vascular system. The disease is caused by mutations in the ABCC6 gene and is characterized by calcification and extracellular matrix remodeling, including alterations of the vessel walls. Here, we investigated the cell adhesion molecules ICAM-1 in PXE patients.

METHODS

Soluble ICAM-1 was determined in 58 non-consanguineous PXE patients by quantitative sandwich enzyme immunoassay. The allelic frequencies of the ICAM-1 variant p.K469E were analyzed in patients and age- and sex-matched controls.

RESULTS

Soluble ICAM-1 levels were significantly elevated in male and female PXE patients (p<0.02 and p<0.001, respectively). In addition, the ICAM-1 concentration correlated with the ABCC6 gene status of the PXE patients. The ICAM variant p.K469E genotypes were not different in PXE patients and age- and sex-matched controls.

CONCLUSIONS

Our data show for the first time increased ICAM-1 concentrations in PXE patients, potentially due to the chronic oxidative stress and elevated protease activity followed by extracellular matrix remodeling which have been previously observed in PXE patients.

Endothelial dysfunction: a key to the pathophysiology and natural history of peripheral arterial disease?

Dysfunctional endothelium plays a crucial role in all stages of atherosclerosis and thus the accurate assessment of this organ is a valuable tool, especially if such assessments are clinically relevant. In peripheral arterial disease (PAD), which affects about 27 million of individuals in Europe and North America, increased plasma markers of endothelial dysfunction and reduced endothelium-mediated vasoreactivity, are associated with both the severity and the extent of atherosclerosis in the arteries of the lower limbs, is exacerbated by acute exercise, may help identify subjects with subclinical coronary artery disease, and portends a worse outcome. As a result, endothelial dysfunction is a promising target for therapeutic interventions in PAD. Large clinical trials are needed to verify whether affected individuals with depressed endothelial function benefit from specific treatments.

Intercellular adhesion molecule 1 (ICAM1) Lys56Met and Gly241Arg gene variants, plasma-soluble ICAM1 concentrations, and risk of incident cardiovascular events in 23,014 initially healthy white women

BACKGROUND AND PURPOSE

The objective of this study was to examine the association of 2 nonsynonymous intercellular adhesion molecule 1 (ICAM1) gene variants (Lys56Met and Gly241Arg) with baseline plasma soluble ICAM1 concentrations and with risk of total and selected cardiovascular disease (CVD) events in a prospective cohort of 23 014 apparently healthy white American women followed for 10 years. ICAM1 variations have been associated with plasma soluble ICAM1 concentrations and inflammatory conditions, including atherosclerosis. However, to date, no large prospective, genetic-epidemiological data set is available that would allow evaluation of the degree of association of these gene variants with risk of CVD.

METHODS

ICAM1 genotypes and baseline plasma soluble ICAM1 concentrations were determined. The primary outcome measure was a composite CVD end point (incident ischemic stroke, myocardial infarction, or death due to ischemic CVD); other measures were incident ischemic stroke, myocardial infarction, and coronary revascularization. During follow-up, 751 total incident CVD events, 187 incident myocardial infarction cases, 203 incident ischemic stroke cases, and 433 coronary revascularization events occurred.

RESULTS

All observed genotype frequencies were in Hardy-Weinberg equilibrium across the whole sample population. We found baseline plasma soluble ICAM1 concentrations to be significantly reduced among carriers of Met56 allele (P<0.0001) and Arg241 allele (P<0.0001) as compared with the respective noncarriers of these variants. However, the polymorphisms tested and the respective haplotypes were neither associated with overall risk nor with risk with risk for selected CVD events regardless of whether analyses were adjusted for traditional CVD risk factors/confounders (all P values >0.10).

CONCLUSIONS

In this large prospective study, we found an association of the nonsynonymous gene variants tested with reduced baseline plasma soluble ICAM1 concentrations. However, no evidence was found for an association of the gene variants tested with the overall or selected CVD end points examined, suggesting that these variants may not add useful aids to current risk predictors for early assessment of cardiovascular events.

Genetic susceptibility to peripheral arterial disease: a dark corner in vascular biology

Peripheral arterial disease (PAD) is characterized by reduced blood flow to the limbs, usually as a consequence of atherosclerosis, and affects approximately 12 million Americans. It is a common cause of cardiovascular morbidity and an independent predictor of cardiovascular mortality. Similar to other atherosclerotic diseases, such as coronary artery disease, PAD is the result of the complex interplay between injurious environmental stimuli and genetic predisposing factors of the host. Genetic susceptibility to PAD is likely contributed by sequence variants in multiple genes, each with modest effects. Although many of these variants probably alter susceptibility both to PAD and to coronary artery disease, it is likely that there exists a set of variants specifically to alter susceptibility to PAD. Despite the prevalence of PAD and its high societal burden, relatively little is known about such genetic variants. This review summarizes our limited present knowledge and gives an overview of recent, more powerful approaches to elucidating the genetic basis of PAD. We discuss the advantages and limitations of genetic studies and highlight the need for collaborative networks of PAD investigators for shedding light on this dark corner of vascular biology.

Cellular adhesion molecules and peripheral arterial disease

Cellular adhesion molecules (CAMs), by mediating the recruitment of circulating leukocytes to the blood vessel wall and their subsequent migration into the subendothelial spaces, play a crucial role in all stages of atherosclerosis. Soluble forms of CAMs, probably derived from proteolytic shedding, are present in the circulation and their blood levels parallel the amount expressed on the cell surface. In patients with peripheral arterial disease (PAD), increased levels of soluble CAMs have been found during exercise-induced claudication, are associated with the presence, the severity and the extent of atherosclerosis in the arteries of the lower limbs, and portend a worse outcome. These findings have provided new insights into the pathophysiology of PAD and its consequences. However, further large population studies are needed to firmly establish whether increased levels of circulating CAMs give additive information to current risk assessment approaches, and to verify whether PAD patients with elevated levels of circulating CAMs would benefit from any specific therapy.

Selected gene polymorphisms and their interaction with maternal smoking, as risk factors for gastroschisis

BACKGROUND

Gastroschisis is a severe birth defect in which the infant is born with a portion of the intestines extruding through a small tear in the abdominal wall, usually to the right of the umbilical cord. Its etiology is unknown, but the prevailing hypothesis is that it results from a vascular accident at the time of involution of the right umbilical vein or of the development of the superior mesenteric artery.

METHODS

In a case-control study of 57 cases of gastroschisis and 506 controls, we tested DNA for polymorphisms of 32 genes representing enzymes involved in angiogenesis, blood vessel integrity, inflammation, wound repair, and dermal or epidermal strength.

RESULTS

In logistic regression, controlling for maternal ethnicity, and using the homozygote wild-type as referent, the following gene polymorphisms were associated with an increased risk for a gastroschisis for heterozygotes: ICAM1 gly241arg (odds ratio [OR], 1.9; 95% confidence interval [CI], 1.1 -3.4); NOS3 glu298asp (OR, 1.9; 95% CI, 1.1-3.4); NPPA 2238T > C (OR, 1.9; 95% CI, 1.0-3.4); and ADD1 gly460trp (OR, 1.5; 95% CI, 0.8-2.8). Additionally, for the NPPA and ADD1 single-nucleotide polymorphisms (SNPs), the homozygote variants had a significantly higher risk than the heterozygotes (OR, 7.5; 95% CI, 1.7-33.5 and OR, 4.9; 95% CI, 1.9-12.9, respectively). Three SNPs showed a strong interaction with maternal smoking. The risk for smokers with 1 or 2 variant alleles compared to nonsmokers with the wild-type allele were: NOS3 (OR, 5.2; 95% CI, 2.4-11.4); ICAM1 (OR, 5.2; 95% CI, 2.1-12.7); and NPPA (OR, 6.4; 95% CI, 2.8-14.6).

CONCLUSIONS

These results support the hypothesis of a vascular compromise as part of a multifactorial etiology of gastroschisis involving both genes and environmental factors.

Contemporaneous carrier-state of two or three "proatherosclerotic" variants of APOE, ICAM1, PPARA and PAI-1 genes differentiate CAD patients from healthy individuals

BACKGROUND

Atherosclerosis is the most important cause of coronary artery disease (CAD). Genetic predisposition to CAD is related to polymorphisms of genes encoding products functionally involved in pathogenesis of atherosclerosis. Polymorphisms of genes participating in monocyte adhesion and diapedesis, lipid metabolism and fibrinolysis regulation may be partially responsible for this process. The aim of our study was to assess the polymorphic variants frequencies of ICAM1, APOE, PPARA and PAI-1 genes in CAD patients and healthy blood donors and to find specific arrangement of polymorphic variants which would differentiate both groups.

METHODS

We studied 146 CAD patients and 121 healthy blood donors. Polymorphisms in analyzed genes were examined using PCR-RFLP analysis.

RESULTS

We found significantly higher frequency of 5G allele of PAI-1 gene in patients than in control subjects (p = 0.038, OR = 1.44). We observed also a considerably higher frequency of contemporaneous carriers of two or three "proatherosclerotic" variants: 1) PPARA and PAI-1, 2) APOE and ICAM1 and 3) PPARA, ICAM1 and PAI-1 in CAD group comparing to control subjects. The number of "proatherosclerotic" variants carriers differentiate studied groups also independently of specific genotype arrangement.

CONCLUSION

In conclusion, contemporaneous carrier-state of two or three polymorphic variants within analyzed genes is associated with CAD.

The K469E polymorphism of the intercellular adhesion molecule-1 gene is associated with plasma fibrinogen level in type 2 diabetes

Intercellular adhesion molecule-1 (ICAM-1) is involved in inflammation and development of atherosclerotic change of vascular endothelium. The aim of the present study is to investigate whether K469E polymorphism of the ICAM-1 gene is associated with various clinical factors including plasma fibrinogen in patients with type 2 diabetes. ICAM-1 gene polymorphism was examined using polymerase chain reaction and restriction enzyme analysis in 360 type 2 diabetic patients. Plasma fibrinogen levels and other clinical variables were measured as well as circulating soluble ICAM-1 (sICAM-1) levels by enzyme-linked immunosorbent assay. The distribution of ICAM-1 genotypes, EE, EK, and KK, was not significantly different between type 2 diabetes and 152 healthy control subjects. Among 3 groups according to ICAM-1 genotypes in type 2 diabetes, no difference was found in adiposity, glycemic control, lipid profile, insulin sensitivity evaluated by homeostasis model assessment, or sICAM-1. Regarding fibrinogen, the patients with E allele showed significantly lower plasma fibrinogen levels in a dose-dependent manner (P = .033). Spearman rank correlation analyses revealed that ICAM-1 genotype showed significant correlation with plasma fibrinogen level (P < .001). In multiple regression analysis, ICAM-1 genotype was independent contribution factor of plasma fibrinogen level as well as high-density lipoprotein-cholesterol and urinary albumin excretion (R2 = 0.148, P < .001). In conclusion, K469E polymorphism of the ICAM-1 gene had impact on plasma fibrinogen level independently of other clinical factors in 360 type 2 diabetic patients, suggesting that fibrinogen is a candidate which links the ICAM-1 gene polymorphism to atherosclerosis.

Intercellular Adhesion Molecule 1 (ICAM-1) Gene Variant is Associated with Coronary Artery Calcification Independent of Soluble ICAM-1 Levels

Background

Although circulating levels of soluble intercellular adhesion molecule 1 (slCAM-1) predict cardiovascular events, no studies have examined intercellular adhesion molecule 1 (ICAM-1) gene variants, plasma slCAM-1 levels, and atherosclerosis in the same sample.

Methods

We examined the association of the ICAM-1 K469E gene variant and plasma slCAM-1 with coronary artery calcification (CAC) in 632 asymptomatic subjects, recruited on the basis of a family history of premature cardiovascular disease.

Results

In age-adjusted ordinal regression, slCAM-1 levels were associated with CAC (odds ratio [OR] [95% confidence interval (CI)] 1.30 [1.04–1.6] per 100 ng/dL slCAM-1; p = .02), but this association was lost after adjusting for traditional risk factors (OR [95% CI] 0.9 [0.69–1.16]). In men, but not women (interaction p = .018), the ICAM-1 K469E GG genotype predicted lower CAC after adjusting for traditional risk factors (OR [95% CI] 0.33 [0.17–0.61]; p = .001) and further controlling for plasma slCAM-1 (OR [95% CI] 0.27 [0.14–0.52]; p < .001). Conclusions: In a study sample specifically selected for the characteristic of a family history of premature coronary heart disease, ICAM K469E GG was associated with lower CAC scores in men but not women even after controlling for plasma levels of slCAM-1. These studies suggest that ICAM-1 variants may modulate atherosclerosis in humans and provide support for the concept that inflammatory gene polymorphisms may influence atherosclerosis independent of plasma levels of their gene products.

Proinflammatory Genetic Profiles in Subjects With History of Ischemic Stroke

BACKGROUND AND PURPOSE

Proinflammatory genetic profiles, resulting from the combination of single nucleotide polymorphisms in genes encoding inflammatory molecules, may contribute to the development and progression of cardiovascular diseases. We evaluated the association between history of ischemic stroke and genetic profiles determined by the synergistic effects of polymorphisms in genes encoding prototypical inflammatory proteins.

METHODS

The study included 237 individuals with history of ischemic stroke and 223 age-matched and gender-matched controls. The polymorphisms of the C-reactive protein (CRP), interleukin-6 (IL-6), macrophage migration inhibitory factor (MIF), monocyte chemoattractant protein-1 (MCP-1), intercellular adhesion molecule-1 (ICAM-1), E-selectin (E-sel), and matrix metalloproteinase-3 (MMP-3) genes were studied.

RESULTS

IL-6 GG, IL-6 GC, MCP-1 GG, ICAM-1 EE, E-sel AA, and MMP-3 5A5A genotypes were significantly and independently associated with stroke history. The odds of stroke increased with the number of high-risk genotypes: carrying 1 proinflammatory gene variant conferred a risk of 3.3 (1.6 to 6.9), whereas individuals concomitantly carrying 2 and 3 proinflammatory gene variants had adjusted odds ratios of 21.0 (7.6 to 57.5) and 50.3 (10.2 to 248.1), respectively.

CONCLUSIONS

Proinflammatory genetic profiles are significantly more common in subjects with stroke history. Synergistic effects between proinflammatory genotypes might be potential markers for cerebrovascular diseases.

Adhesion molecules and atherosclerosis

One early phase of atherosclerosis involves the recruitment of inflammatory cells from the circulation and their transendothelial migration. This process is predominantly mediated by cellular adhesion molecules, which are expressed on the vascular endothelium and on circulating leukocytes in response to several inflammatory stimuli. Selectins (P, E and L) and their ligands (mainly P-selectin ligand) are involved in the rolling and tethering of leukocytes on the vascular wall. Intercellular adhesion molecules (ICAMs) and vascular cell adhesion molecules (VCAM-1), as well as some of the integrins, induce firm adhesion of inflammatory cells at the vascular surface, whereas platelet endothelial cellular adhesion molecules (PECAM-1) are involved in extravasation of cells from the blood compartment into the vessel and underlying tissue. For most of the cellular adhesion molecules, except integrins, soluble forms have been identified in the circulation although their origins are not fully understood. Several lines of evidence support a crucial role of adhesion molecules in the development of atherosclerosis and plaque instability. Expression of VCAM-1, ICAM-1 and L-selectin has been consistently observed in atherosclerotic plaques. There is accumulating evidence from prospective studies for a predictive role of elevated circulating levels of sICAM-1 in initially healthy people, and of sVCAM-1 in patients at high risk or with overt CAD. A large number of common polymorphisms has been identified in the genes encoding the different adhesion molecules, but studies investigating their relationship either with soluble forms or with CAD are still sparse and often based on small samples. Further research is needed to firmly establish the potential clinical and therapeutic utilities of (soluble) adhesion molecules, but results in both fields hold the promise that in future, adhesion molecules might add information for clinical risk prediction and serve as therapeutic targets.

Synergistic effect of -174 G/C polymorphism of the interleukin-6 gene promoter and 469 E/K polymorphism of the intercellular adhesion molecule-1 gene in Italian patients with history of ischemic stroke

BACKGROUND AND PURPOSE

Interleukin-6 (IL-6) and intercellular adhesion molecule-1 (ICAM-1) are involved in the pathogenetic mechanisms responsible for several ischemic cardiovascular disorders, including cerebral ischemia. IL-6 and ICAM-1 plasma levels and/or function may be genetically influenced. We sought to evaluate distribution and reciprocal interaction of IL-6 G/C gene promoter polymorphism and ICAM-1 E/K gene polymorphism in Italian patients with history of ischemic stroke.

METHODS

One hundred nineteen patients with history of ischemic stroke and 133 age- and sex-matched controls were studied. IL-6 and ICAM-1 genotypes were evaluated by polymerase chain reaction and restriction enzyme analysis.

RESULTS

The GG genotype of -174 IL-6 G/C gene polymorphism was significantly associated with history of ischemic stroke at both univariate (P<0.0001) and multivariate analysis (odds ratio [OR], 8.6; P<0.0001). Additionally, the EE genotype of ICAM-1 E/K gene polymorphism was significantly more common in the group of patients with history of ischemic stroke (P=0.003) and was an independent variable associated with stroke history (OR, 4.0; P=0.002). Interestingly, a further increased risk of stroke was found in subjects who concomitantly carry the IL-6 GG and ICAM-1 EE genotypes (IL-6 GG/ICAM-1 EE double-homozygous subjects) (OR, 10.1; P=0.004).

CONCLUSIONS

There is a synergistic effect of IL-6 G/C and ICAM-1 E/K gene polymorphisms in patients with stroke history. Reciprocal interactions between genotypes may contribute in determining the risk profile for cardiovascular diseases and may merit further investigation as potential therapeutic targets.