Browsing by Author "Novkovic, Mirjana (57191976429)"

Purpose: Bleeding is one of the possible adverse events during clopidogrel therapy. The CYP2C19 gene is the most significant genetic factor which influences response to clopidogrel treatment. We aimed to examine the contribution of the CYP2C19 gene to bleeding occurrence during clopidogrel therapy in Serbian patients with ST segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI). Methods: This case–control study included 53 patients who experienced bleeding and 55 patients without bleeding. Bleeding events were defined and classified using the Bleeding Academic Research Consortium (BARC) criteria. All patients were prescribed daily doses of clopidogrel during the 1-year follow-up after PCI. The CYP2C19*17 (c.-806C>T, rs12248560), rs11568732 (c.-889T>G, CYP2C19*20), CYP2C19*2 (c.681G>A; rs4244285) and CYP2C19*3 (c.636G>A; rs4986893) variants were analysed in all 108 patients. Additionally, sequencing of all nine exons, 5′UTR and 3′UTR in the rs11568732 carriers was performed. Results: Association between bleeding (BARC type ≥ 2) and the CYP2C19*17 variant was not observed [odds ratio (OR), 0.53; 95% confidence interval (CI), 0.2–1.1; p = 0.107). The rs11568732 variant showed significant association with bleeding (OR, 3.7; 95% CI, 1.12–12.44; p = 0.025). Also, we found that the rs11568732 variant appears independently of haplotype CYP2C19*3B, which is contrary to the previous findings. Conclusions: Our results indicate the absence of CYP2C19*17 influence and turn the attention to the potential significance of the rs11568732 variant in terms of adverse effects of clopidogrel. However, it is necessary to conduct an independent conformation study in order to verify this finding. Also, an analysis of the functional implication of the rs11568732 variant is necessary in order to confirm the significance of this variant, both in relation to its influence on gene expression and in relation to its medical significance. © 2017, Springer-Verlag GmbH Germany, part of Springer Nature.

Purpose: Bleeding is one of the possible adverse events during clopidogrel therapy. The CYP2C19 gene is the most significant genetic factor which influences response to clopidogrel treatment. We aimed to examine the contribution of the CYP2C19 gene to bleeding occurrence during clopidogrel therapy in Serbian patients with ST segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI). Methods: This case–control study included 53 patients who experienced bleeding and 55 patients without bleeding. Bleeding events were defined and classified using the Bleeding Academic Research Consortium (BARC) criteria. All patients were prescribed daily doses of clopidogrel during the 1-year follow-up after PCI. The CYP2C19*17 (c.-806C>T, rs12248560), rs11568732 (c.-889T>G, CYP2C19*20), CYP2C19*2 (c.681G>A; rs4244285) and CYP2C19*3 (c.636G>A; rs4986893) variants were analysed in all 108 patients. Additionally, sequencing of all nine exons, 5′UTR and 3′UTR in the rs11568732 carriers was performed. Results: Association between bleeding (BARC type ≥ 2) and the CYP2C19*17 variant was not observed [odds ratio (OR), 0.53; 95% confidence interval (CI), 0.2–1.1; p = 0.107). The rs11568732 variant showed significant association with bleeding (OR, 3.7; 95% CI, 1.12–12.44; p = 0.025). Also, we found that the rs11568732 variant appears independently of haplotype CYP2C19*3B, which is contrary to the previous findings. Conclusions: Our results indicate the absence of CYP2C19*17 influence and turn the attention to the potential significance of the rs11568732 variant in terms of adverse effects of clopidogrel. However, it is necessary to conduct an independent conformation study in order to verify this finding. Also, an analysis of the functional implication of the rs11568732 variant is necessary in order to confirm the significance of this variant, both in relation to its influence on gene expression and in relation to its medical significance. © 2017, Springer-Verlag GmbH Germany, part of Springer Nature.

Objectives: A considerable number of patients do not achieve an adequate response to clopidogrel. Our study aimed to evaluate genetic and non-genetic factors as possible risks for clopidogrel high on-treatment platelet reactivity (HTPR) in patients (n=112) with carotid artery stenosis undergoing endarterectomy (CEA). Methods: Using multiple-electrode impedance aggregometry (MEA) the antiplatelet effectiveness of clopidogrel was measured after 24 h, 7 and 30 days of clopidogrel treatment, which was introduced after elective CEA at a dose of 75 mg daily, for at least 30 days. Results: HTPR was observed among 25% patients after clopidogrel therapy for 30 days. Further analysis showed that 53.3% of patients carrying the CYP2C19*2 gene variant had clopidogrel-HTPR, while in the wild type group there were 14.6% (p<0.001). Multivariate logistic regression analysis identified the CYP2C19*2 variant allele (OR 4.384; 95% CI 1.296-14.833, p=0.017) and high total cholesterol level (OR 2.090; 95% CI 1.263-3.459, p=0.004) as the only independent risk factors for clopidogrel-HTPR. Conclusion: The CYP2C19*2 gene variant and high total cholesterol level were major factors for clopidogrel-HTPR in patients with carotid artery stenosis undergoing CEA. © 2016 Bentham Science Publishers.

Objectives: A considerable number of patients do not achieve an adequate response to clopidogrel. Our study aimed to evaluate genetic and non-genetic factors as possible risks for clopidogrel high on-treatment platelet reactivity (HTPR) in patients (n=112) with carotid artery stenosis undergoing endarterectomy (CEA). Methods: Using multiple-electrode impedance aggregometry (MEA) the antiplatelet effectiveness of clopidogrel was measured after 24 h, 7 and 30 days of clopidogrel treatment, which was introduced after elective CEA at a dose of 75 mg daily, for at least 30 days. Results: HTPR was observed among 25% patients after clopidogrel therapy for 30 days. Further analysis showed that 53.3% of patients carrying the CYP2C19*2 gene variant had clopidogrel-HTPR, while in the wild type group there were 14.6% (p<0.001). Multivariate logistic regression analysis identified the CYP2C19*2 variant allele (OR 4.384; 95% CI 1.296-14.833, p=0.017) and high total cholesterol level (OR 2.090; 95% CI 1.263-3.459, p=0.004) as the only independent risk factors for clopidogrel-HTPR. Conclusion: The CYP2C19*2 gene variant and high total cholesterol level were major factors for clopidogrel-HTPR in patients with carotid artery stenosis undergoing CEA. © 2016 Bentham Science Publishers.

The correct Author names are shown in this paper. The original article was corrected. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature.

The correct Author names are shown in this paper. The original article was corrected. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), responsible for the COVID-19 pandemic, has been evolving rapidly causing emergence of new variants and health uncertainties. Monitoring the evolution of the virus was of the utmost importance for public health interventions and the development of national and global mitigation strategies. Here, we report national data on the emergence of new variants, their distribution, and dynamics in a 3-year study conducted from March 2020 to the end of January 2023 in the Republic of Serbia. Nasopharyngeal and oropharyngeal swabs from 2,398 COVID-19-positive patients were collected and sequenced using three different next generation technologies: Oxford Nanopore, Ion Torrent, and DNBSeq. In the subset of 2,107 SARS-CoV-2 sequences which met the quality requirements, detection of mutations, assignment to SARS-CoV-2 lineages, and phylogenetic analysis were performed. During the 3-year period, we detected three variants of concern, namely, Alpha (5.6%), Delta (7.4%), and Omicron (70.3%) and one variant of interest—Omicron recombinant “Kraken” (XBB1.5) (<1%), whereas 16.8% of the samples belonged to other SARS-CoV-2 (sub)lineages. The detected SARS-CoV-2 (sub)lineages resulted in eight COVID-19 pandemic waves in Serbia, which correspond to the pandemic waves reported in Europe and the United States. Wave dynamics in Serbia showed the most resemblance with the profile of pandemic waves in southern Europe, consistent with the southeastern European location of Serbia. The samples were assigned to sixteen SARS-CoV-2 Nextstrain clades: 20A, 20B, 20C, 20D, 20E, 20G, 20I, 21J, 21K, 21L, 22A, 22B, 22C, 22D, 22E, and 22F and six different Omicron recombinants (XZ, XAZ, XAS, XBB, XBF, and XBK). The 10 most common mutations detected in the coding and untranslated regions of the SARS-CoV-2 genomes included four mutations affecting the spike protein (S:D614G, S:T478K, S:P681H, and S:S477N) and one mutation at each of the following positions: 5′-untranslated region (5’UTR:241); N protein (N:RG203KR); NSP3 protein (NSP3:F106F); NSP4 protein (NSP4:T492I); NSP6 protein (NSP6: S106/G107/F108 - triple deletion), and NSP12b protein (NSP12b:P314L). This national-level study is the most comprehensive in terms of sequencing and genomic surveillance of SARS-CoV-2 during the pandemic in Serbia, highlighting the importance of establishing and maintaining good national practice for monitoring SARS-CoV-2 and other viruses circulating worldwide. Copyright © 2024 Novkovic, Banovic Djeri, Ristivojevic, Knezevic, Jankovic, Tanasic, Radojicic, Keckarevic, Vidanovic, Tesovic, Skakic, Tolinacki, Moric and Djordjevic.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), responsible for the COVID-19 pandemic, has been evolving rapidly causing emergence of new variants and health uncertainties. Monitoring the evolution of the virus was of the utmost importance for public health interventions and the development of national and global mitigation strategies. Here, we report national data on the emergence of new variants, their distribution, and dynamics in a 3-year study conducted from March 2020 to the end of January 2023 in the Republic of Serbia. Nasopharyngeal and oropharyngeal swabs from 2,398 COVID-19-positive patients were collected and sequenced using three different next generation technologies: Oxford Nanopore, Ion Torrent, and DNBSeq. In the subset of 2,107 SARS-CoV-2 sequences which met the quality requirements, detection of mutations, assignment to SARS-CoV-2 lineages, and phylogenetic analysis were performed. During the 3-year period, we detected three variants of concern, namely, Alpha (5.6%), Delta (7.4%), and Omicron (70.3%) and one variant of interest—Omicron recombinant “Kraken” (XBB1.5) (<1%), whereas 16.8% of the samples belonged to other SARS-CoV-2 (sub)lineages. The detected SARS-CoV-2 (sub)lineages resulted in eight COVID-19 pandemic waves in Serbia, which correspond to the pandemic waves reported in Europe and the United States. Wave dynamics in Serbia showed the most resemblance with the profile of pandemic waves in southern Europe, consistent with the southeastern European location of Serbia. The samples were assigned to sixteen SARS-CoV-2 Nextstrain clades: 20A, 20B, 20C, 20D, 20E, 20G, 20I, 21J, 21K, 21L, 22A, 22B, 22C, 22D, 22E, and 22F and six different Omicron recombinants (XZ, XAZ, XAS, XBB, XBF, and XBK). The 10 most common mutations detected in the coding and untranslated regions of the SARS-CoV-2 genomes included four mutations affecting the spike protein (S:D614G, S:T478K, S:P681H, and S:S477N) and one mutation at each of the following positions: 5′-untranslated region (5’UTR:241); N protein (N:RG203KR); NSP3 protein (NSP3:F106F); NSP4 protein (NSP4:T492I); NSP6 protein (NSP6: S106/G107/F108 - triple deletion), and NSP12b protein (NSP12b:P314L). This national-level study is the most comprehensive in terms of sequencing and genomic surveillance of SARS-CoV-2 during the pandemic in Serbia, highlighting the importance of establishing and maintaining good national practice for monitoring SARS-CoV-2 and other viruses circulating worldwide. Copyright © 2024 Novkovic, Banovic Djeri, Ristivojevic, Knezevic, Jankovic, Tanasic, Radojicic, Keckarevic, Vidanovic, Tesovic, Skakic, Tolinacki, Moric and Djordjevic.