Angiotensin-converting enzyme gene and endothelial nitric oxide synthase gene polymorphisms in Behçet’s disease with or without ocular involvement

Association of the angiotensin I converting enzyme (ACE) gene polymorphisms with recurrent aphthous stomatitis in the Czech population: case–control study

Background

Recurrent aphthous stomatitis (RAS) is multifactorial disease with unclear etiopathogenesis. The aim of this study was to determine distribution of the angiotensin I converting enzyme (ACE) gene polymorphisms and their influence on RAS susceptibility in Czech population.

Methods

The study included 230 subjects (143 healthy controls and 87 patients with RAS) with anamnestic, clinical and laboratory data. Five ACE gene polymorphisms (rs4291/rs4305/rs4311/rs4331/rs1799752 = ACE I/D) were determined by TaqMan technique.

Results

The allele and genotype distributions of the studied ACE I/D polymorphisms were not significantly different between subjects with/without RAS (P_corr > 0.05). However, carriers of II genotype were less frequent in the RAS group (OR = 0.48, 95% CI = 0.21–1.12, P = 0.059). Stratified analysis by sex demonstrated lower frequency of II genotype in women (OR = 0.33, 95% CI = 0.09–1.17, P < 0.035, P_corr > 0.05, respectively) than in men with RAS (P > 0.05). Moreover, the frequency of AGTGD haplotype was significantly increased in RAS patients (OR = 13.74, 95% CI = 1.70–110.79, P = 0.0012, P_corr < 0.05). In subanalysis, TGD haplotype was significantly more frequent in RAS patients (P < 0.00001) and CGI haplotype was less frequent in RAS patients (P < 0.01), especially in women (P = 0.016, P_corr > 0.05).

Conclusions

Our study indicates that while the AGTGD and TGD haplotypes are associated with increased risk of RAS development, CGI haplotype might be one of protective factors against RAS susceptibility in Czech population.

Histopathological comparison of pathergy positive and negative areas of newly diagnosed Behçet patients

BACKGROUND

Behcet's disease is an inflammatory vasculitis, and pathergy reaction is a compulsory element of the diagnostic criteria. In the literature, there is no study comparing the histopathology of negative pathergy tests and positive pathergy tests in newly diagnosed Behcet's patients. The primary goal was to investigate the frequency of vasculitis, which is an important finding of Behcet's disease, in pathergy histopathology.

METHODS

The histopathology of patients with positive and negative pathergy tests revealed vasculitis or vasculopathy. In histopathology, neutrophils, lymphocytes, eosinophils, and mast cells in the perivascular area were counted and recorded as a percentage.

RESULTS

Of the 88 Behcet's patients who participated in the study, 45 were female and 43 were male. The rate of vasculitis in the histopathology of those who were positive for the pathergy test was not statistically different than those of those with negative pathergy tests (P = .14). In our study, although the relationship between the male gender and uveitis was significant at the border, and the relationship between pathergy positivity and uveitis was not found to be significant, a significant relationship was found between vasculitis in histopathology and uveitis (P = .023).

CONCLUSIONS

Based on the results of our study, we think that a pathergy test of histopathology will contribute to the clinical diagnostic evaluation in cases with suspicious clinical pathergy tests and especially in cases with negative pathergy tests.

Tumor necrosis factor (TNF)-308, -1031, and angiotensin-converting enzyme (ACE) DD/II polymorphisms' role in Behcet's disease with and without uveitis: a meta-analysis

PURPOSE

There are conflicting results of studies investigating the association between the tumor necrosis factor (TNF) and angiotensin-converting enzyme (ACE) gene polymorphisms and Behcet's disease (BD). The aim of this meta-analysis is to assess the association between these gene polymorphisms and ocular involvement in BD.

METHODS

We identified relevant studies and reviewed the full-text manuscripts of the studies in order to select those for inclusion. Heterogeneity of studies was evaluated using Cochran Q-test and I-square index. To modify the heterogeneity in the variables we used random effects model. Meta-analysis was performed using STATA.

RESULTS

We analyzed TNF-1031, -308 and ACE DD/II genotype difference between BD patients with and without uveitis. Among these polymorphic genetic loci TNF-308 AA genotype has a statistically significant protective effect against BD uveitis (OR = 0.45 vs 1.23, p = .017). Such a statistically significant effect was not seen for other studied genotypes.

CONCLUSION

This meta-analysis revealed a significant protective effect of TNF-308 AA genotype against ocular involvement in Behcet's disease.

Antioxidant and Anti-Inflammatory Effects of Blueberry Anthocyanins on High Glucose-Induced Human Retinal Capillary Endothelial Cells

Blueberries possess abundant anthocyanins, which benefit eye health. The purpose of this study was to explore the protective functional role of blueberry anthocyanin extract (BAE) and its predominant constituents, malvidin (Mv), malvidin-3-glucoside (Mv-3-glc), and malvidin-3-galactoside (Mv-3-gal), on high glucose- (HG-) induced injury in human retinal capillary endothelial cells (HRCECs). The results showed that BAE, Mv, Mv-3-glc, and Mv-3-gal enhanced cell viability (P < 0.05 versus the HG group at 24 h); decreased the reactive oxygen species (ROS, P < 0.01 versus the HG group both at 24 and 48 h); and increased the enzyme activity of catalase (CAT) and superoxide dismutase (SOD) (P < 0.05 versus the HG group both at 24 and 48 h). Mv could greatly inhibit HG-induced Nox4 expression both at 24 and 48 h (P < 0.05), while BAE and Mv-3-gal downregulated Nox4 only at 48 h (P < 0.05). Mv, Mv-3-glc, and Mv-3-gal also changed nitric oxide (NO) levels (P < 0.05). BAE and Mv-3-glc also influenced angiogenesis by decreasing the vascular endothelial cell growth factor (VEGF) level and inhibiting Akt pathway (P < 0.05). Moreover, Mv and Mv-3-glc inhibited HG-induced intercellular adhesion molecule-1 (ICAM-1, P < 0.001) and nuclear factor-kappa B (NF-κB) (P < 0.05). It indicated that blueberry anthocyanins protected HRCECs via antioxidant and anti-inflammatory mechanisms, which could be promising molecules for the development of nutraceuticals to prevent diabetic retinopathy.

Insertion/deletion polymorphism of the ACE gene increased risk of Behcet disease: evidence from a meta-analysis

BACKGROUND AND OBJECTIVES

Endothelial dysfunction has a role in the development of the Behcet disease (BD). Local renin-angiotensin system (RAS) plays a crucial role in the endothelial control, and angiotensin-converting enzyme (ACE) is the monitoring component of the RAS. We investigated the relationship between the ACE Ins/Del (I/D) variants and the risk of BD.

DESIGN AND SETTINGS

A meta-analysis was conducted from all published studies on the associations be.tween the ACE I/D polymorphism and BD.

METHODS

We systemically searched all published studies from PubMed and EMBASE, and data were quantitatively synthesized. Pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated for allele, homozygous, heterozygous, and combined genetic models.

RESULTS

Out of 5 eligible studies, 676 healthy controls and 534 BD cases were included in the present meta.analysis. D allele carrier was significantly associated with increased BD risk (D vs I: P=.002; OR=1.321, 95% CI=1.111-1.570). Homozygous mutant DD genotype also revealed 1.5-fold increased risk (DD vs II; P=.004; OR=1.573, 95% CI=1.156-2.141). In addition, the dominant genetic model demonstrated an increased risk of developing BD (DD vs II+ID: P=.001; OR=1.610, 95% CI=1.242-2.087).

CONCLUSION

The current study suggests that ACE gene polymorphism (Ins/Del) contributes an increased susceptibility to BD. However, larger studies with stratified case control population and biological characterization are needed to validate this finding.

Associations between the angiotensin-converting enzyme insertion/deletion polymorphism and susceptibility to vasculitis: a meta-analysis

Introduction: To explore whether the insertion (I) and deletion (D) polymorphism of angiotensin-converting enzyme ( ACE) confers susceptibility to vasculitis.

Materials and methods: A meta-analysis was conducted on the associations between the ACE I/D polymorphism and vasculitis.

Results: Twelve studies, including four on Behçet’s disease (BD), four on Henoch–Schenlein purpura (HSP), three on Kawasaki disease (KD), and one on Wegener’s granulomatosis, were available for the meta-analysis. Meta-analysis showed that the DD + ID genotype was associated with susceptibility to vasculitis (odds ratio [OR] 1.468, 95% confidence interval [CI] 1.214–1.468, p = 7.4 × 10−5). The overall OR for the D allele was significantly increased in BD (OR 1.313, 95% CI 1.017–1.695). Meta-analysis of the DD+ID genotype, the DD genotype and the DD vs. II genotype showed marginal associations with BD, but meta-analysis of the D allele, and the DD+ID genotype showed significant associations with HSP (OR 1.446, 95% CI 1.021–2.049, p = 0.038; OR 1.881, 95% CI 1.385–2.595, p = 6.6 × 10−5). On the other hand, meta-analysis showed no association between KD and the ACE I/D polymorphism.

Conclusions: This meta-analysis shows that the ACE I/D polymorphism is associated with vasculitis susceptibility, especially in BD and HSP.

[The genetics of vasculitides]

Genetic association studies have been of great value in the past by contributing to the understanding of pathophysiological mechanisms of chronic inflammatory and autoimmune diseases. Many genetic risk factors have been identified which confer susceptibility for one or several (autoimmune) disease(s). Using a candidate-gene approach, the first genetic risk factors and polymorphisms of vasculitides have been identified. Due to the rarity of autoimmune vasculitides often only small sample numbers have been generated and analysed, leading to inconsistent results. Furthermore, differences in ethnic background may complicate analysis. Only few of the detected risk factors have been reliably replicated in larger cohorts, such as the association of the PTPN22*620W allele with WG and MPA, the deficiency allele Pi*Z of the alpha1 antitrypsin gene and the HLA-DPB*04041 allele with WG and the HLA-DRB3/DRB4 with CSS. Genome-wide association studies (GWAS) offer the advantage of screening the whole genome for risk factors rather than relying on disease models postulated by the investigator; however, they require even larger sample sizes. Initial results from GWA studies are available for Behçet's disease and Kawasaki syndrome, which identified new genetic associations but require replication, especially since some of the identified risk factors could not be linked to pathophysiological pathways to date.

The skin pathergy test: innately useful?

Pathergy is the term used to describe hyper-reactivity of the skin that occurs in response to minimal trauma. A positive skin pathergy test (SPT), characterised by erythematous induration at the site of the needle stick with a small pustule containing sterile pus at its centre, is among the criteria required for a diagnosis of Behçet's disease (BD) and in certain population has been shown to be highly specific for this condition. Problems with standardising the induction manoeuvre for the SPT as well as the method of assessment of the response have limited the usefulness of the SPT in the clinical setting. Extensive investigation into histopathological and immunological aspects of pathergy has led to a number of hypotheses relating to the aetiology of the skin pathergy reaction and the disease itself, but the cause is considered to be unknown. Pathergy lesions, the development of new skin lesions or the aggravation of existing ones following trivial trauma, are also reported in pyoderma gangrenosum and has been noted in other neutrophilic dermatoses such as Sweet's syndrome. The response of such patient groups to the systematic application of the SPT has not been described. We propose that a new way of considering the pathergy reaction is to see it as an aberration of the skin's innate reactivity from a homeostatic reactive mode closely coupled to tissue healing to an abnormal destructive/inflammatory mode. Our understanding of BD and other similar conditions would profit by more detailed mechanistic knowledge of skin homeostasis to minimal trauma in both health and disease through a more structured and systematic use of the SPT.