Lakhdar Ghazouani

University of Monastir, Tunis-Ville, Tūnis, Tunisia

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Publications (12)21.58 Total impact

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    ABSTRACT: A state of low-grade inflammation accompanies the pathogenesis of atherosclerotic events. Interleukin-6 (IL-6) is a pleotropic pro-inflammatory cytokine that modulates the development of acute coronary syndromes (ACSs), partly by destabilizing coronary atherosclerotic plaques. We have examined the contribution of the -174G>C IL-6 promoter variant on the risk of coronary artery disease (CAD) among Tunisians. Study subjects included 418 CAD patients and 406 age- and sex-matched controls. IL-6 genotyping was done by PCR-restriction fragment length polymorphism. The frequency of the -174C allele (mutant) was lower in Tunisians than in Europeans, and the distribution of -174 G>C genotypes was similar between CAD patients and control subjects. Moreover, compared to GG genotype carriers, -174C allele carriage did not increase the CAD relative risk (odds ratio and 95% confidence interval=1.09 and 0.80-1.49), which remained nonsignificant after adjusting for traditional risk factors for CAD (age, smoking, hypertension, diabetes and obesity). The -174G>C IL-6 promoter variant is not associated with an increased risk of CAD among Tunisians.
    Annals of Saudi medicine 01/2011; 31(1):40-4. · 1.10 Impact Factor
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    ABSTRACT: Our aim was to evaluate the contribution of tumor necrosis factor (TNF)-alpha -308G>A and interleukin (IL)-6 -174G>C gene promoter variants to the presence of coronary artery disease (CAD) in Tunisians. Study subjects comprised 418 angiographically proven CAD patients and 406 age-, gender-, and ethnic origin-matched controls. Genotyping was performed using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis. There were no significant differences in the allelic distribution of TNF-alpha -308A (19.6% vs. 19.0%, P=0.73), and IL-6 -174C (15.6% vs. 14.3%, P=0.47) promoter polymorphisms between CAD patients and control subjects, respectively. In addition, single locus analysis revealed no differences in genotype frequencies between the two study groups, and the combined distribution of both genotypes did not differ significantly between controls and CAD patients (P>0.05). There is no allelic or genotypic association of TNF-alpha -308G>A and IL-6 -174G>C promoter polymorphisms with CAD in Tunisians, thereby confirming an ethnic-selective contribution of both gene variants to CAD presence.
    Clinical biochemistry 09/2010; 43(13-14):1085-9. · 2.02 Impact Factor
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    ABSTRACT: The contribution of interleukin (IL)-10 promoter variants -1082G/A, -819C/T, and -592C/A to the risk of coronary artery disease (CAD) was investigated in 291 CAD patients and 291 age- and gender-matched control subjects. IL-10 genotyping was performed using PCR-allele-specific amplification (PCR-ASA). Regression analysis was employed in assessing the contribution of the IL-10 variants to the overall CAD risk. A higher frequency of the -592A allele (p = 0.004), but not the -1082A (p = 0.828) or -819T (p = 0.952) alleles, was seen in CAD patients. A higher frequency of -592C/A (p = 0.011), and a lower frequency of -592C/C (p = 0.015) genotypes was noted in patients compared to healthy controls. Regression analysis demonstrated an association of -592C/A [OR (95% CI) = 1.82 (1.02-3.23)] and -592A/A [OR (95% CI) = 3.33 (1.27-9.09)] genotypes with 1-artery disease. Haplotype analysis revealed that none of the eight possible IL-10 haplotypes was associated with CAD or with the severity of CAD, and was confirmed by multivariate regression analysis, after adjusting for a number of confounders (smoking, systolic and diastolic blood pressure, hypertension, diabetes, glucose, cholesterol, and triglycerides). Our results suggest that the -592C/A, more so than the -1082G/A or the -819C/T IL-10 promoter variant alleles, may be considered to be a risk factor for CAD in Tunisians.
    European cytokine network. 06/2010; 21(2):136-41.
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    ABSTRACT: P-selectin (SELP) and its counter-receptor, P-selectin glycoprotein ligand-1 (PSGL-1), play key role in the transient attachment of leukocytes to endothelial cells predisposing to coronary heart disease (CHD). In the current report, 293 angiographically proven CHD patients and 327 age, gender, and race-matched controls were included. Our aim was to evaluate the contribution to CHD of the following SNPs: C-2123G, G-1969A and T715P in SELP, Met62Ile and the VNTR variants in PSGL-1 gene in a North African population from Tunisia. While there were no significant differences in the distribution of SELP or PSGL-1 alleles or genotypes between patients and controls, a trend for a significant association of the C-2123G genotypes distribution with incident CHD was observed (P=0.06). Assuming an additive model of transmission, the risk was 74% higher among subjects carrying the GG genotypes in comparison to those carrying the CC genotype (OR=1.74 [1.01-2.98], P=0.04) and 80% higher in the recessive model (OR=1.80 [1.08-3.01], P=0.02). Haplotype analysis did not identify any specific SELP or PSGL-1 haplotypes to be associated with CHD. The present study demonstrated no evidence of association between individual SELP or PSGL-1 SNPs or haplotypes with incident CHD. However, this study replicates absence of association of the mostly studied SNP, T715P, previously reported in individuals with African origin.
    Molecular Biology Reports 04/2010; 38(1):495-501. · 2.51 Impact Factor
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    ABSTRACT: Myocardial infarction (MI) is induced by acquired and inherited risk factors, including the plasminogen activator inhibitor-1 (PAI-1) -844G/A and -675G/A (4G/5G) gene variants. The aim of this study was to investigate the association between PAI-1-844G/A and 4G/5G polymorphisms and changes in PAI-1 and tissue plasminogen activator (tPA) levels in MI in a Tunisian population. This was a case-control study involving 305 patients with MI and 328 unrelated healthy controls. PAI-1 genotyping was done by polymerase chain reaction-restriction fragment length polymorphism (RFLP) (-844G/A) or by polymerase chain reaction-allele specific amplification. PAI-1 and tPA levels were assayed by serological assays. In contrast to tPA levels, mean plasma PAI-1 antigen levels were higher in cases than in control subjects. The elevation in PAI-1 levels was more pronounced in -844A and 4G allele carriers. Significantly higher frequencies of (mutant) 4G and -844A alleles and 4G/4G and -844A/-844A genotypes, and corresponding lower frequencies of (wild-type) 5G and -844G alleles and 5G/5G and -844G/-844G genotypes were seen in patients than in controls. Increased prevalence of 4G/-844A and decreased prevalence of 5G/-844G haplotypes were seen in patients than in controls, thereby conferring a susceptibility and protective nature to these haplotypes, respectively. Regression analysis confirmed the independent association of 4G/4G and -844A/A with MI, after controlling for a number of covariates. This study indicated that the risk of MI was notably high in 4G and -844A carriers with elevated plasma PAI-1 and were associated with reduced tPA levels.
    Genetic Testing and Molecular Biomarkers 11/2009; 14(1):23-7. · 1.44 Impact Factor
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    ABSTRACT: Recent research has shown that inflammation plays a key role in coronary artery disease (CAD) and other manifestations of atherosclerosis. Several lines of evidence support a key role for tumor necrosis factor-alpha (TNF-alpha), a potent immunomodulator and pro-inflammatory cytokine, in the development of atherosclerosis and in complications of CAD. We investigated the possible association between CAD and the TNF gene promoter polymorphisms -308G>A and -1031T>C in a Tunisian population. We compared the distribution of these polymorphisms between 418 patients with CAD and 406 healthy controls using polymerase chain reaction restriction fragment length-polymorphism analysis. The frequency of the TNF-alpha -308A allele in the control group was similar to that observed in CAD patients [p=0.78; odds ratio (OR)=1.15; 95% confidence interval (CI)=0.86-1.55], but higher than those described in other Europeans, such as in the French, Finnish and Spanish. Concerning the TNF-alpha -1031T/C polymorphism, the same distribution was observed between patients with CAD and controls (p=0.12; OR=1.27; 95% CI=0.94-1.72). In addition, the genotype and allele frequencies of control individuals were comparable to those previously reported in healthy Tunisian controls and other ethnic groups. Haplotype analysis (TNF-alpha -308G>A and -1031T>C) demonstrated no significant association between TNF haplotypes and CAD. We conclude that TNF promoter gene polymorphisms at position -308G>A and -1031T>C do not play a major role in the pathogenesis of CAD in the Tunisian population.
    Clinical Chemistry and Laboratory Medicine 01/2009; 47(10):1247-51. · 3.01 Impact Factor
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    ABSTRACT: P-selectin plays a key role in inflammation and atherosclerosis, and polymorphic variants of P-selectin were implicated in the pathogenesis of atherosclerotic and inflammatory changes, including coronary heart disease (CHD) in many ethnic groups. We investigated the contribution of P-selectin promoter (-2123C/G, -1969G/A) and exon (Ser290Asn, Asn562Asp, Thr715Pro) polymorphisms to CHD genetic susceptibility among 298 Tunisian CHD patients and 339 controls. Minor allele and genotype frequencies of the five P-selectin SNPs were comparable between patients and controls, except for -2123G/G genotype which was more frequent in cases. The 715Pro allele was present at lower frequency in Tunisians than in Europeans, and was not protective of CHD. Linkage disequilibrium was seen between -1969G/A, and both Ser290Asn and Asn562Asp. Five-loci haplotype analysis did not identify any CHD-protective or CHD-susceptible haplotypes. To our knowledge, this was the first case-control study to be performed on an Arab/North-African population, and demonstrates that none of the five P-selectin polymorphisms investigated influence CHD susceptibility in Tunisian Arabs.
    Journal of Thrombosis and Thrombolysis 01/2009; 28(3):314-9. · 1.99 Impact Factor
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    ABSTRACT: Elevation in homocysteine and methylenetetrahydrofolate reductase (MTHFR) gene variants, C677T and A1298C, have been linked with atherothrombosis. However their exact contribution to coronary artery disease (CAD) remains controversial. Moreover, data from Tunisian patients are scarse. We examined the association of MTHFR C677T and A1298C, and changes in plasma homocysteine in 352 Tunisian patients with angiographically-demonstrated CAD, and 390 age and gender-matched healthy subjects. Significantly higher frequency of 677T allele and homozygous 677T/T genotype were seen in patients vs. control subjects; the distribution of A1298C alleles and genotypes being comparable in the two groups. Specific MTHFR haplotypes comprising 677C/1298A (P < 0.001) and 677T/1298A (P < 0.001) were negatively and positively associated with CAD, respectively. Plasma homocysteine concentration was significantly higher in 677T/T genotype with respect to 677C/C and 677C/T genotypes in patients and controls, but homocysteine levels were generally comparable between both groups. Univariate analysis identified 677T/1298A (P = 0.033) haplotype to be positively associated with CAD, which remained significant by multivariate analysis after adjusting for a number of covariates (P = 0.038). MTHFR C677T, but not A1298C SNPs, is associated with CAD and with elevated homocysteine levels in a Tunisian population. The negative and positive association of the 1298A allele with CAD being indicative of a neutral (absent) effect of the A1298C SNP on disease pathogenesis.
    Journal of Thrombosis and Thrombolysis 02/2008; 27(2):191-7. · 1.99 Impact Factor
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    ABSTRACT: Because they have been described as strong risk factors for idiopathic recurrent pregnancy losses (RPLs), we assessed the association between the methylenetetrahydrofolate reductase (MTHFR) single-nucleotide polymorphisms (SNPs) C677T and A1298C and hyperhomocysteinemia in Tunisian women with idiopathic RPL. Study subjects comprised 200 patients with more than three consecutive RPLs, and 200 age-matched parous control women. C677T and A1298C SNPs were analyzed by PCR-RFLP analysis, and fasting serum homocysteine was measured with ELISA. The frequency of MTHFR 677T/T (30.0 vs 7.0%) and 1298C/C (13.5 vs 4.0%) genotypes was significantly higher in patients. While it was similar among patients and controls (P = 0.095), higher homocysteine was seen with the T/T (but not 1298A/C and 1298C/C) genotype among patients and controls compared with non-T/T carriers (P < 0.05), and in patients vs controls. Higher prevalence of MTHFR 677T/T was seen in late (P < 0.05) and early-late (P < 0.001) RPL, while higher prevalence of 1298C/C genotype was seen only in early-late RPL (P < 0.001), and the prevalence of double heterozygotes was statistically not significant between patients and controls (P = 0.10; odds ratio = 2.73). Logistic regression analysis showed that, after adjusting for all variables, homozygosity for MTHFR C677T was associated with late (P < 0.001), and combined early-late (P < 0.001), while homozygosity for A1298C was associated only with combined early-late (P = 0.026), as was secondary-level education, which was associated with early (P = 0.005), late (P = 0.026) and combined early-late (P = 0.004) abortions. Homozygosity for MTHFR C677T (late and early-late) and A1298C (early-late) are risk factor for RPLs, irrespectively of total homocysteine levels.
    Reproduction (Cambridge, England) 03/2006; 131(2):395-401. · 3.56 Impact Factor
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    ABSTRACT: P-selectin plays a key role in inflammation and atherosclerosis, and polymorphic variants of P-selectin were implicated in the pathogenesis of atherosclerotic and inflammatory changes, including coronary heart disease (CHD) in many ethnic groups. We investigated the contribution of P-selectin promoter (−2123C/G, −1969G/A) and exon (Ser290Asn, Asn562Asp, Thr715Pro) polymorphisms to CHD genetic susceptibility among 298 Tunisian CHD patients and 339 controls. Minor allele and genotype frequencies of the five P-selectin SNPs were comparable between patients and controls, except for −2123G/G genotype which was more frequent in cases. The 715Pro allele was present at lower frequency in Tunisians than in Europeans, and was not protective of CHD. Linkage disequilibrium was seen between −1969G/A, and both Ser290Asn and Asn562Asp. Five-loci haplotype analysis did not identify any CHD-protective or CHD-susceptible haplotypes. To our knowledge, this was the first case-control study to be performed on an Arab/North-African population, and demonstrates that none of the five P-selectin polymorphisms investigated influence CHD susceptibility in Tunisian Arabs.
    Journal of Thrombosis and Thrombolysis 28(3):314-319. · 1.99 Impact Factor
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    ABSTRACT: Despite extensive exploration of many genes, strong evidence of a molecular genetic association with coronary heart disease (CHD) or myocardial infarction (MI) remains to be obtained. Recently, significant interest has emerged in mapping genetic susceptibility for complex traits through whole-genome studies association generating promoting data that will determine the genetic contribution to common human diseases such as coronary heart disease. The aim of the present case-control study including 324 healthy controls and 296 patients with coronary heart disease from Tunisia, was to assess relation between three polymorphisms previously reported to be strongly associated with coronary heart disease in the Welcome Trust Case Control Consortium (WTCCC) and the German myocardial infarction family studies: locus 9p21.3 (rs 1333049), locus 6q25.1 (rs6922269) and 2q36.3 (rs2943634). By single locus analysis, no differences in genotype distribution and allelic frequency were found between the two groups of study. The risk allele (C) for rs2943634 was less frequent among Tunisian population than in controls from the WTCCC and German studies (57% vs 65%). The three SNPs previously reported to be associated with CHD were not replicated in our small sample.
    Journal of Thrombosis and Thrombolysis 29(1):114-118. · 1.99 Impact Factor
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    ABSTRACT: Background Myocardial Infarction (MI) was reportedly precipitated by acquired and inherited risk factors including the G/A and 4G/5G polymorphisms within the promoter of the Plasminogen Activator Inhibitor -1 (PAI-1) gene. Objective to investigate the association between gene polymorphism of the PAI-1 and MI in Tunisian. Methods PAI-1 G/A was genotyped with polymerase chain reaction — restriction fragment length polymorphism (PCR-RFLP) while PAI-1 4G/5G promoter genotype was established by allele specific polymerase chain reaction amplification of genomic DNA. This study was performed in 305 myocardial infarction patients and 328 unrelated healthy controls. All subjects clinical features and PAI-1 and t-PA activity were tested. Results There were two polymorphisms within the promoter (a G/A single base substitution polymorphism at -844 bp upstream from the start of transcription and an insertion (5G)/deletion (4G) polymorphism at position — 675). Higher frequency of the 4G allele (p < 0.001; O.R. = 1.929), but a lower frequency of the 5G allele (p < 0.001; O.R. = 0.356), were seen in patients vs. controls. The frequencies of the -844G (p < 0.001; O.R. = 0.314) allele was lower than -844A allele (p < 0.001; O.R. = 4.076) in patients versus controls. Furthermore significant elevation in plasma PAI-1 levels (88.43 ± 52.85 ng/ml vs. 62.18 ± 39.31 ng/ml; p <0.05) was seen among patients. Conclusion This study indicates that the risk of MI was notably high in 4G carriers and A carriers with elevated plasma PAI-1, and were associated with reduced t-PA levels.
    Archives of Cardiovascular Diseases. 102:S12.