Sevastianos Chatzidavid

Dr. Sevastianos Chatzidavid

orcid

Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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Verified
Journal Article
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SCSevastianos Chatzidavid
Sevastianos Chatzidavid
PFPagona Flevari
Pagona Flevari
ITIoanna Tombrou
Ioanna Tombrou
GAGeorge Anastasiadis
George Anastasiadis
MDMaria N. Dimopoulou
Maria N. Dimopoulou
Pulmonary hypertension (PH) is a progressive and potentially fatal complication of sickle cell disease (SCD), affecting 6–10% of adult SCD patients. Various mechanisms and theories have been evaluated to explain the pathophysiology of this disease. However, questions remain, particularly regarding the clinical heterogeneity of the disease in terms of symptoms, complications, and survival. Beyond the classical mechanisms that have been thoroughly investigated and include hemolysis, nitric oxide availability, endothelial disorders, thrombosis, and left heart failure, attention is currently focused on the potential role of genes involved in such processes. Potential candidate genes are investigated through next-generation sequencing, with the transforming growth factor-beta (TGF-β) pathway being the initial target. This field of research may also provide novel targets for pharmacologic agents in the future, as is already the case with idiopathic PH. The collection and processing of data and samples from multiple centers can yield reliable results that will allow a better understanding of SCD-related PH as a part of the disease’s clinical spectrum. This review attempts to capture the most recent findings of studies on gene polymorphisms that have been associated with PH in SCD patients.

1 January 2024 in Advances in Hematology
Verified
Journal Article
Open access
SCSevastianos Chatzidavid
Sevastianos Chatzidavid
CKChristina-Nefeli Kontandreopoulou
Christina-Nefeli Kontandreopoulou
NGNefeli Giannakopoulou
Nefeli Giannakopoulou
PDPanagiotis Theodorou Diamantopoulos
Panagiotis Theodorou Diamantopoulos
CSChristos Stafylidis
Christos Stafylidis
NVNora-Athina Viniou
Nora-Athina Viniou
Epigenetic regulation has been thoroughly investigated in recent years and has emerged as an important aspect of chronic lymphocytic leukemia (CLL) biology. Characteristic aberrant features such as methylation patterns and global DNA hypomethylation were the early findings of the research during the last decades. The investigation in this field led to the identification of a large number of genes where methylation features correlated with important clinical and laboratory parameters. Gene‐specific analyses investigated methylation in the gene body enhancer regions as well as promoter regions. The findings included genes and proteins involved in key pathways that play central roles in the pathophysiology of the disease. Τhe application of these findings beyond the theoretical understanding can not only lead to the creation of prognostic and predictive models and scores but also to the design of novel therapeutic agents. The following is a review focusing on the present knowledge about single gene/gene promoter methylation or mRNA expression in CLL cases as well as records of older data that have been published in past papers.

22 February 2023 in Clinical Hematology International
Verified
Journal Article
Open access
PDF file
SCSevastianos Chatzidavid
Sevastianos Chatzidavid
CKChristina-Nefeli Kontandreopoulou
Christina-Nefeli Kontandreopoulou
PDPanagiotis T. Diamantopoulos
Panagiotis T. Diamantopoulos
NGNefeli Giannakopoulou
Nefeli Giannakopoulou
PKPanagiota Katsiampoura
Panagiota Katsiampoura
NVNora-Athina Viniou
Nora-Athina Viniou
Ribonucleotide Reductase (RNR) converts ribonucleotides to deoxyribonucleotides required for DNA replication and repair. RNR consists of subunits M1 and M2. It has been studied as a prognostic factor in several solid tumors and in chronic hematological malignancies, but not in chronic lymphocytic leukemia (CLL). Peripheral blood samples were collected from 135 CLL patients. M1/M2 gene mRNA levels were measured and expressed as a RRM1-2/GAPDH ratio. M1 gene promoter methylation was studied in a patients’ subgroup. M1 mRNA expression was higher in patients without anemia (p = 0.026), without lymphadenopathy (p = 0.005) and 17p gene deletion (p = 0.031). Abnormal LDH (p = 0.022) and higher Rai stage (p = 0.019) were associated with lower M1 mRNA levels. Higher M2 mRNA levels were found in patients without lymphadenopathy (p = .048), Rai stage 0 (p = 0.025) and Trisomy 12 (p = 0.025). The correlation between RNR subunits and clinic-biological characteristics in CLL patients demonstrate RNR’s potential role as a prognostic factor.

8 October 2024 in Leukemia & Lymphoma
Verified
Journal Article
Closed access
SSStavroula Syriopoulou
Stavroula Syriopoulou
CKChristina-Nefeli Kontandreopoulou
Christina-Nefeli Kontandreopoulou
PDPanagiotis T. Diamantopoulos
Panagiotis T. Diamantopoulos
DVDimitra Vlachopoulou
Dimitra Vlachopoulou
CSChristos Stafylidis
Christos Stafylidis
FGfor the Hellenic MDS Study Group
for the Hellenic MDS Study Group
MiRNAs have been identified as participants in leukemogenesis by controlling several cellular functions, such as differentiation, proliferation, and apoptosis. Their role in myelodysplastic neoplasms (MDS) pathogenesis is researched due to implementations in early identification, classification, and therapeutical options. IPSS-R, being the most widely used MDS classification, underestimates early biological events that can alter the disease's prognosis. The purpose of this study is to determine whether miRNA levels are aligned to MDS risk stratification groups and can therefore be used as diagnostic biomarkers. To evaluate miRNAs as possible biomarkers, we measured the levels of miR-181a-2-3p, miR-124-3p, miR-550a-3p, miR-155-5p, miR-151a-3p, and miR-125b-5p by a quantitative real-time PCR in bone marrow samples of 41 MDS patients. In conclusion, in myeloid malignancies, genomic characteristics may provide a wider apprehension of its clinical course and prognosis. MiRNAs constitute a possible diagnostic biomarker and therapeutic target, allowing intermediate-risk patients that express high levels of specific miRNAs to be re-classified and receive more advanced therapeutic agents. In our study, an association between high levels of miRNAs and worsening outcomes is established, supporting the need for further incorporation of molecular data into currently used classification systems.

1 April 2024 in Preprints.org
Verified
Preprint
Open access
PDF file
SCSevastianos Chatzidavid
Sevastianos Chatzidavid
PFPagona Flevari
Pagona Flevari
ITIoanna Tombrou
Ioanna Tombrou
GAGeorge Anastasiadis
George Anastasiadis
MDMaria N. Dimopoulou
Maria N. Dimopoulou
Pulmonary hypertension (PH) is a progressive and potentially fatal complication of sickle cell disease (SCD) affecting 6-10% of adult SCD patients. Various mechanisms and theories have been evaluated to explain the pathophysiology of the disease. However, questions remain, particularly regarding the clinical heterogeneity of the disease in terms of symptoms, complications, and survival. Beyond the classical mechanisms that have been thoroughly investigated and include hemolysis, nitric oxide availability, endothelial disorders, thrombosis, and left heart failure, attention is focused nowadays on the potential role of the genes involved in such processes. Potential candidate genes are investigated through next-generation sequencing, with the TGF-β pathway being the initial target. This field of research may also provide novel targets for pharmacologic agents in the future as is already the case with idiopathic PH. The collection and processing of data and samples from multiple centers can yield safe results that will allow a better understanding of SCD-related PH as a part of the disease’s clinical spectrum. The following review attempts to capture the most recent findings of studies on gene polymorphisms that have been associated with PH in SCD patients.

24 February 2026 in Leukemia & Lymphoma
Verified
Journal Article
Closed access
DVDimitra Vlachopoulou
Dimitra Vlachopoulou
CKChristina-Nefeli Kontandreopoulou
Christina-Nefeli Kontandreopoulou
PDPanagiotis T. Diamantopoulos
Panagiotis T. Diamantopoulos
SSStavroula Syriopoulou
Stavroula Syriopoulou
CSChristos Stafylidis
Christos Stafylidis
HGHellenic MDS Study Group
Hellenic MDS Study Group
Myelodysplastic neoplasms (MDS) are a heterogenous group of clonal hematopoietic disorders defined by inefficient hematopoiesis and morphologic dysplasia that involves a least one of the three myel...