Olivia Turri

Matrix Metalloproteinase-1 and Matrix Metalloproteinase-3 Gene Promoter Polymorphisms Are Associated With Carotid Artery Stenosis

Background and Purpose— The matrix metalloproteinases (MMPs) are a family of enzymes that are important in the resorption of extracellular matrix and are involved in atherogenesis. Recently, 2 common polymorphisms on MMP-1 (1G/2G) and MMP-3 (5A/6A) gene promoters have been described. The aim of this study was to investigate a possible association between MMP polymorphisms and increased risk of internal carotid artery (ICA) stenosis. Methods— We studied 91 patients consecutively recruited for ICA stenosis who had undergone carotid endarterectomy and 133 subjects without ICA stenosis (controls). Polymorphic genotypes were determined by polymerase chain reaction and sequencing analysis. Results— The frequency of the 6A allele was significantly different between cases and controls: 0.62 and 0.50, respectively (odds ratio [OR], 1.58; 95% CI, 1.08 to 2.33;P =0.017). The frequency of 6A/6A genotype was significantly higher in cases with involvement of both carotids (OR, 3.13; 95% CI, 1.14 to 8.5;P =0.026) and in patients with stenosis >70% (OR, 2.55; 95% CI, 1.07 to 6.07;P =0.033). No significant differences were observed in MMP-1 distribution. Patients who were homozygous for both the 6A and 2G alleles had an elevated relative risk of ICA stenosis (OR, 2.66; 95% CI, 1.23 to 5.72;P =0.016). Multiple logistic regression analysis using the common risk factors and the 6A and 2G allele variants revealed that the 6A allele was an independent risk factor for ICA stenosis (P =0.049). When 6A/6A and 2G/2G were combined, the risk factor for ICA stenosis was 3-fold higher (OR, 3.31; 95% CI, 1.48 to 7.42;P =0.004). Conclusions— Homozygosity for the 6A allele of the MMP-3 promoter is associated with carotid stenosis and, in association with MMP-1 2G homozygosity, predicts an increased risk of ICA stenosis. Even if obtained from a relatively limited patient series, these results might have relevant implications for treatment of ICA stenosis and possibly prevention of carotid-related stroke.

Matrix GLA Protein Gene Polymorphisms: Clinical Correlates and Cardiovascular Mortality in Chronic Kidney Disease Patients

Background: Increased vascular calcification plays an important role in the pathogenesis of cardiovascular events in chronic kidney disease (CKD) patients. It is the result of an active ossification process counteracted by ‘protective’ proteins, such as matrix GLA protein (MGP). Polymorphisms of MGP have been identified. Methods: The aim of this study was to define the distribution of two MGP polymorphisms (–7, –138) in 99 hemodialysis (HD) patients, in 26 patients with CKD stage 3 and in 135 age- and sex-matched healthy controls. Patients were followed up for 12 months to record any cardiovascular deaths. The cause of death was determined by medical doctors, considering the medical history of each patient. The primers were designed with Primer Express software. Results: MGP –138TT homozygotes were more frequent in the HD group versus controls (p = 0.0004). Additionally, the frequency of the T allele was significantly higher in the HD group (p = 0.0006). The frequency of the A allele of MGP-7 was significantly higher both in the HD group (p = 0.033) and in the CKD group (p = 0.0017) versus controls. MGP-7 GG homozygotes were significantly less common in the CKD group than in controls (p = 0.037). Combination –138TT –7AA was significantly more frequent in both CKD patients (p = 0.001) and in HD patients (p = 0.029) than in controls. Seventeen out of 99 HD patients experienced fatal cardiovascular events. Sixteen (94.1%) were –138TT homozygotes and either –7AA homozygotes or –7GA heterozygotes. Conclusion: This study suggests that CKD and HD patients have a different distribution of MGP gene polymorphism as compared with the normal population. Altered MGP gene polymorphism may be a negative prognostic factor for the progression to end-stage renal disease and for cardiovascular events in CKD patients.

Serum fetuin-A levels link inflammation and cardiovascular calcification in hemodialysis patients

Background: Cardiovascular disease (CVD) is the leading cause of mortality in hemodialysis (HD). An elevated incidence of cardiovascular calcifications (CVC) is observed in HD. Fetuin-A is an important inhibitor of CVC. Reduced fetuin-A levels associate with inflammation and increased cardiovascular (CV) mortality in HD. In this study we investigated the association of fetuin-A levels and CVC. Method: We evaluated a cohort of 115 patients (67 males), aged 63 ± 16 years with a HD vintage ≧9 months. Presence of CVC was assessed by ultrasound imaging of the abdominal aorta, common carotid arteries, bilateral ilio-femoral axis, aortic and mitral cardiac valves. The presence of CVC was analyzed as a CVC score (CVCS) (0–7) according to the number of CVC sites. Patients were arbitrary stratified in three groups: group I (CVCS = 0), group II (0 < CVCS < 6) and group III (CVCS ≧ 6). Patients without CVC were younger, non-diabetic and with a negative history for CV events. Results: Patients with evidence of CVC in more than 5 sites had lower serum fetuin-A levels (0.41 ± 0.22 g/l) compared to patients with CVCS = 0 (0.51 ± 0.17 g/l, p = 0.048). In addition a worse CVCS was associated with higher serum levels of C-reactive protein (p = 0.002) and fibrinogen (p < 0.001). Serum fetuin-A levels lower than 0.290 g/l were associated with higher risk of a worse CVCS, independently from traditional risk factors. Conclusion: Chronic inflammation in HD patients leads to lower serum fetuin-A levels. The present study confirms the independent and significant association between reduced serum fetuin-A levels and multi-site CVC in HD.

Internal carotid artery occlusive disease and polymorphisms of fractalkine receptor CX3CR1: A genetic risk factor

Background and Purpose— Fractalkine (FKN), a chemokine expressed by inflamed endothelium, induces leukocyte adhesion and migration via the receptor CX3CR1. The polymorphisms V249I and T280M affect receptor expression and function. The role of FKN in atherosclerosis has been recently demonstrated. The aim of this study was to investigate a possible association between CX3CR1 polymorphisms and increased risk of internal carotid artery (ICA) occlusive disease. Methods— We studied 108 patients consecutively recruited for ICA occlusive disease, 84 of whom underwent operation for carotid endarterectomy, and 204 subjects without ICA occlusive disease (controls). Polymorphic genotypes were determined by polymerase chain reaction and sequencing analysis. Results— The adjusted odds ratio (OR) associated with the presence of the M280 (TM+MM versus TT genotype) was 0.55 (95% CI: 0.29 to 0.99; P = 0.037). Therefore, this allele is associated with a reduced risk of ICA occlusive disease. No significant differences were observed in I249 distribution. The frequency of I249 allele was significantly higher in cases of hard plaques, which are considered more stable than soft ones (OR: 0.38; 95% CI: 0.13 to 1.05; P = 0.037). Multiple logistic regression analysis using the common risk factors and the I249 and M280 allele variants revealed that the M280 allele was an independent risk factor for ICA stenosis (P = 0.047). Conclusion— The results show that the CX3CR1 M280 is an independent genetic risk factor for ICA occlusive disease and that I249 is involved in the stability of carotid plaques. Even if obtained from a relatively limited patient series, these results might have relevant implications for treatment of ICA stenosis and possibly prevention of carotid related stroke. Further prospective cross-sectional studies are needed to confirm these results.

High resolution melting analysis to genotype the most common variants in the HFE gene.

Abstract Background: High resolution melting (HRM) analysis of PCR amplicons was recently introduced as a closed-tube, rapid, and inexpensive method of genotyping. This study evaluated this system as an option for detecting the three most common mutations in the HFE gene (C282Y, H63D, S65C), accounting for the main form of hereditary haemochromatosis. Methods: Ninety samples, previously screened by direct sequencing, and 27 controls were used. The analysis were performed on the Rotor Gene Q, using the commercial HRM mix containing the Eva Green dye (Qiagen). Specific primers allowed the amplification of the regions of interest in the HFE gene. Following amplification, a HRM analysis was conducted to detect DNA variants. The thermal denaturation profiles of the samples were compared with those of the controls. Results: One hundred percent of heterozygous and homozygous samples were readily identified. Heterozygotes were easily identified because heteroduplexes altered the shape of the melting curves, but significant differences were also present in the melting curves of the homozygous carries compared with those of the wild-type subjects. Conclusions: HRM analysis is an appealing technology for HFE gene screening. It is a robust technique that can be widely adopted in diagnostic laboratories to facilitate gene mutation screening.

Polymorphism of Interleukin 28 and HCV: Implementation of a method

HCV infection represents a global health problem. Only 20-30% of patients affected by HCV infection recovers spontaneously, while the remaining patients develop a chronic infection with risk of evolution to cirrhosis and hepatocarcinoma. Nowadays, approximately 50% of individuals with hepatitis C infection is not responding to therapy with pegylated alphainterferon and ribavirin. Polymorphisms (SNPs) of the gene coding for the interleukin 28 (IL28) have recently been described and they are in strong relationship with the outcome of HCV infected patients. In particular, the polymorphism rs12979860 (C/T), located 3 kb upstream of the gene, is associated to a rapid and early response to therapy (genotype C/C). Consequently we have developed a method in high resolution melting (HRM), which allows a simple and rapid screening of polymorphism rs12979860. The validation of the method was carried out by analyzing the IL28 genotype of 50 patients already determined by sequencing. Sensitivity and specificity of the method were found to be equal to 100%.Accuracy, precision within and between series were equal to 100%. Compared to other methods described for the analysis of polymorphisms the HRM has the advantage of being faster and safe, relatively cheap and very simple in the optimization phase, therefore, applicable to a large throughput. Up till now we have analyzed 329 patients of which 46 co-infected HCV-HIV. The distribution of the polymorphism obtained is the following: 37% C/C, 51% C/T, 12% T/T.The distribution in the co-infected patients does not differ from that of the total HCV positive patients.We suggest a careful follow up of the therapeutic response of these patients to confirm the clinical usefulness of the test and to determine its true predictive value.

Consultants for the American Journal of Nephrology 2005

Sandra Garber Cybele Ghossein Richard Glassock Alan Go Laurence Greenbaum Karen Griffi n S. Grigoryev Krishnamurthy Gudehithlu Peter Hart Koichi Hayashi Peter Heering Susan Hou John Hoyer Randall Hudson Todd Ing Eunice John Richard Johnson Michelle Josephson Pradeep Kadambi Ramesh Khanna Orly Kohn Jeff Kopp Mark Kraus Jerome Lane Craig Langman James Lash David Leehey Oliver Lenz Edgar Lerma Jerrold Levine Wilfred Lieberthal Stuart Linas Jill Lindberg Natalia Litbarg Gerard London Rodger Loutzenhiser Friedrich Luft K. Matsumoto Peter McCullough Patrick Murray Naoyuki Nakao Kevin Abbott Rajiv Agarwal Sharon Anderson Gema Ariceta John Asplin Simon Atkinson Asad Bakir George Bakris Vinod Bansal Amelia Bartholomew Amy Barton Pai Daniel Batlle Vecihi Batuman Enrico Benedetti Angelito Bernardo Anil Bidani Peter Blake Anthony Bleyer W. Kline Bolton Michael Braun Carolyn Brecklin Harold Bregman Ellen Brooks Vito Campese Sule Cataltepe Nina Clark Jay Cohn Richard Cohn Judith Cook Andrey Cybulsky Mohamed Daha Farhard Danesh Janice Douglas George Dunea Lance Dworkin Beatrice Edwards Leon Ferder Steven Fishbane Kenneth Fisher Mary Foster Barry Freedman