Angiotensin-converting enzyme gene insertion/deletion polymorphism in Korean patients with systemic sclerosis

Autoimmune Disease-Associated Hypertension

Purpose of Review

To highlight important new findings on the topic of autoimmune disease-associated hypertension.

Recent Findings

Autoimmune diseases including systemic lupus erythematosus and rheumatoid arthritis are associated with an increased risk for hypertension and cardiovascular disease. A complex interaction among genetic, environmental, hormonal, and metabolic factors contribute to autoimmune disease susceptibility while promoting chronic inflammation that can lead to alterations in blood pressure. Recent studies emphasize an important mechanistic role for autoantibodies in autoimmune disease-associated hypertension. Moving forward, understanding how sex hormones, neutrophils, and mitochondrial dysfunction contribute to hypertension in autoimmune disease will be important.

Summary

This review examines the prevalent hypertension in autoimmune disease with a focus on the impact of immune system dysfunction on vascular dysfunction and renal hemodynamics as primary mediators with oxidative stress as a main contributor.

Significant correlation of angiotensin converting enzyme and glycoprotein IIIa genes polymorphisms with unexplained recurrent pregnancy loss in north of Iran

BACKGROUND

Spontaneous abortion is considered as the most complex problem during pregnancy. Thrombophilia is resumed as a cause of recurrent pregnancy loss (RPL). Glycoprotein IIIa (GPIIIa) gene is involved in thrombosis and abortion. Angiotensin converting enzyme (ACE) converts angiotensin I to angiotensin II and is involved in thrombosis. The most common polymorphism in this gene is the insertion/deletion (I/D).

OBJECTIVE

In this study, we analyzed the association between ACE I/D and GPIIIa c.98C >T polymorphisms in women with unexplained RPL from the north of Iran.

MATERIALS AND METHODS

Sample population consisted of 100 women with unexplained RPL and 100 controls. The ACE I/D and GPIIIa c.98C>T polymorphisms were genotyped by TETRA-ARMS PCR. The association between genotypes frequency and RPL were analyzed using χ(2) and exact fisher tests. Associated risk with double genotype combinations was also investigated by binary logistic regression.

RESULTS

There was significant association between ACE DD genotype and RPL (OR=2.04; 95% CI=0.94-4.44; p=0.036). ACE D Allele was also significantly associated with the RPL (OR=1.59; 95% CI=1.05-2.41; p=0.013). No significant association was observed between GPIIIa c.98C>T polymorphism and RPL.

CONCLUSION

ACE I/D polymorphism may probably be a prognostic factor in female family members of women with the history of recurrent abortion.

A meta-analysis of the association between cytokine gene polymorphisms and systemic sclerosis

We conducted a comprehensive meta-analysis to quantitatively evaluate the association of cytokine gene polymorphisms with systemic sclerosis (SSc) susceptibility. Electronic databases were used to identify published studies before July 2011. In total, 23 case-control studies including 3524 SSc cases and 6086 healthy controls were included in the meta-analysis. We examined the relationship between five gene polymorphisms [cytotoxic T lymphocyte associated antigen 4 (CTLA-4) -1722T/C, CTLA-4 -318C/T, CTLA-4 +49A/G, angiotensin-converting enzyme I/D, STAT-4 rs7574865] and susceptibility to SSc. The combined odds ratio (OR) with 95% confidence interval (95% CI) was calculated to estimate the strength of the association in a fixed or random effect model. Heterogeneity and publication bias were also assessed. We found a significant association between SSc and STAT rs7574865 (TT vs. GG: OR 0.44, 95% CI 0.36-0.54; TT vs. TG + GG: OR 0.48, 95% CI 0.39-0.59; TT + TG vs. GG: OR 0.74, 95% CI 0.66-0.83; T vs. G: OR 0.72, 95% CI 0.66-0.79), but there were no other statistically significant associations with other gene polymorphisms. Our study suggested that SSc is associated with STAT gene rs7574865 polymorphism.

Angiotensin-Converting Enzyme Gene Does Not Contribute to Genetic Susceptibility to Systemic Sclerosis in European Caucasians

Objective.

To determine whether angiotensin-converting enzyme (ACE) polymorphisms including I/D and 2 single-nucleotide polymorphisms (SNP) affect susceptibility to systemic sclerosis (SSc) in a large French Caucasian population.

Methods.

A case-control study was performed in 494 patients with SSc and 280 healthy controls for I/D polymorphism. Two supplementary exonic SNP of ACE gene (rs4309, rs4362) were genotyped in 659 patients with SSc and 511 matched healthy controls. Among the whole SSc population, 453 (67%) patients with SSc had the limited cutaneous subtype, 47 (7%) had precapillary pulmonary arterial hypertension, 209 (32%) had digital ulcers, and 10 (1.5%) had renal crisis. A combined analysis of the available results for ACE I/D genotypes in Caucasians was also performed.

Results.

There was no association between the 3 polymorphic markers and SSc for allelic and genotype frequencies. No association was observed for the different vascular subsets of the disease. Haplotype analyses did not detect any association. The lack of association for ACE I/D was confirmed by the combined analysis.

Conclusion.

These results in a large cohort of European Caucasian patients with SSc do not support that the ACE gene is implicated in the pathogenesis of SSc and its vascular damage.