Tsvetelina Velikova

Prof. Dr. Tsvetelina Velikova

Sofia University St. Kliment Ohridski, Sofia, Sofia-Grad, Bulgaria
orcid

Research Focus & Metrics

Academic Career Length

13Years (2014-Present)

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

Representative Publications

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30 January 2021 in Rheumatology International
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Journal Article
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Tsvetelina VelikovaTsvetelina Velikova
Tsvetelina Velikova
TGTsvetoslav Georgiev
Tsvetoslav Georgiev
Coronavirus disease 2019 (COVID-19) pandemic has become challenging even for the most durable healthcare systems. It seems that vaccination, one of the most effective public-health interventions, presents a ray of hope to end the pandemic by achieving herd immunity. In this review, we aimed to cover aspects of the current knowledge of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines and vaccine candidates in the light of autoimmune inflammatory diseases (AIIDs) and to analyze their potential in terms of safety and effectiveness in patients with AIIDs. Therefore, a focused narrative review was carried out to predict the possible implications of different types of SARS-CoV-2 vaccines which confer distinct immune mechanisms to establish immune response and protection against COVID-19: whole virus (inactivated or weakened), viral vector (replicating and non-replicating), nucleic acid (RNA, DNA), and protein-based (protein subunit, virus-like particle). Still, there is uncertainty among patients with AIIDs and clinicians about the effectiveness and safety of the new vaccines. There are a variety of approaches towards building a protective immunity against SARS-CoV-2. Only high-quality clinical trials would clarify the underlying immunological mechanisms of the newly implemented vaccines/adjuvants in patients living with AIIDs.

1 January 2021 in BioMed Research International
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Tsvetelina VelikovaTsvetelina Velikova
Tsvetelina Velikova
PKPlamena Kabakchieva
Plamena Kabakchieva
YAYavor Assyov
Yavor Assyov
TGTsvetoslav Georgiev
Tsvetoslav Georgiev
Type 2 diabetes (T2D) is one of the most common chronic metabolic disorders in adulthood worldwide, whose pathophysiology includes an abnormal immune response accompanied by cytokine dysregulation and inflammation. As the T2D‐related inflammation and its progression were associated with the balance between pro and anti‐inflammatory cytokines, anticytokine treatments might represent an additional therapeutic option for T2D patients. This review focuses on existing evidence for antihyperglycemic properties of disease‐modifying antirheumatic drugs (DMARDs) and anticytokine agents (anti‐TNF‐α, anti‐interleukin‐(IL‐) 6, ‐IL‐1, ‐IL‐17, ‐IL‐23, etc.). Emphasis is placed on their molecular mechanisms and on the biological rationale for clinical use. Finally, we briefly summarize the results from experimental model studies and promising clinical trials about the potential of anticytokine therapies in T2D, discussing the effects of these drugs on systemic and islet inflammation, beta‐cell function, insulin secretion, and insulin sensitivity.

Verified
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YDYana Danailova
Yana Danailova
Tsvetelina VelikovaTsvetelina Velikova
Tsvetelina Velikova
GNGeorgi Nikolaev
Georgi Nikolaev
ZMZorka Mitova
Zorka Mitova
ASAlexander Shinkov
Alexander Shinkov
RKRossitza Ts Konakchieva
Rossitza Ts Konakchieva
Since the thyroid gland is one of the organs most affected by autoimmune processes, many patients with thyroiditis of Hashimoto (TH) seek medical advice on lifestyle variance and dietary modifications to improve and maintain their hyroid function. In this review, we aim to present and discuss some challenges associated with the nutritional management of TH, focusing on environmental and dietary deficits, inflammatory and toxic nutrients, cyanotoxins, etc. We discuss the relationships among different diets, chronic inflammation, and microbiota, and their impact on the development and exacerbation of TH in detail. We share some novel insights into the role of vitamin D and melatonin for preserving thyroid function during chronic inflammation in autoimmune predisposed subjects. A comprehensive overview is provided on anti-inflammatory nutrients and ecological diets, including foods for cleansing and detoxification, which represent strategies to prevent relapses and achieve overall improvement of life quality. In conclusion, data from biomedical and clinical studies provide evidence that an appropriate dietary and lighting regimen could significantly improve the function of the thyroid gland and reduce the reactivity of autoantibodies in TH. Compliance with nutritional guidelines may help TH patients to reduce the need for medicines.

1 January 2018 in Endocrine Connections
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EZEmanuela Zaharieva
Emanuela Zaharieva
ZKZdravko Kamenov
Zdravko Kamenov
Tsvetelina VelikovaTsvetelina Velikova
Tsvetelina Velikova
ATAdelina Tsakova
Adelina Tsakova
YEYosif El-Darawish
Yosif El-Darawish
HOHaruki Okamura
Haruki Okamura
Background: Interleukin-18 (IL-18) is an inflammatory cytokine found to be elevated in obesity, metabolic syndrome and type 2 diabetes (T2D) as a part of the chronic low-grade inflammatory process in these states. The aim of the study was to evaluate the interleukin level in patients with latent autoimmune diabetes of the adults (LADA) in comparison to that in T2D subjects. Materials and methods: IL-18 was analyzed through enzyme-linked immunosorbent assay in 76 participants with T2D and 24 with LADA and 14 control subjects. Evaluation was also carried out in body mass index (BMI)- and glycemic control-matched diabetic patients. Results: The serum concentration of IL-18 was higher in patients with T2D (389.04 ± 203.44 pg/mL) and LADA (327.04 ± 144.48 pg/mL) than that in control subjects (219.88 ± 91.03 pg/mL), P < 0.05. However, it was not significantly different between both diabetic groups (P = 0.255) despite higher IL-6 (4.78 ± 5.84 vs 1.79 ± 0.96 pg/mL, P < 0.001) and hs-CRP (2.60 ± 1.70 vs 1.29 ± 1.20 mg/L, P = 0.002) level in T2D patients. The results were persistent in BMI-matched subjects with diabetes (IL-18 = 403.48 ± 226.32 vs 329.30 ± 146.30 pg/mL, respectively for T2D and LADA, P = 0.391). The correlations in T2D group concerning HDL cholesterol (r = −0.377, P = 0.001), postprandial glucose (r = 0.244, P = 0.043), IL-6 (r = 0.398, P < 0.001) and hs-CRP (r = 0.427, P = 0.001) were not confirmed in LADA and control subjects. Conclusion: The IL-18 serum level was higher in T2D and LADA than that in control subjects, but did not differ between both diabetic groups, even when they were BMI matched. Correlations with lipid, glycemic and inflammatory parameters were present in T2D only.

26 February 2024 in Antibodies
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Tsvetelina VelikovaTsvetelina Velikova
Tsvetelina Velikova
MSMetodija Sekulovski
Metodija Sekulovski
Monika Peshevska-SekulovskaMonika Peshevska-Sekulovska
Monika Peshevska-Sekulovska
Many patients with inflammatory bowel disease (IBD) experience a loss of effectiveness to biologic therapy (i.e., anti-TNF therapy, etc.). Therefore, in addition to the adverse effects of the treatment, these patients also face failure to achieve and maintain remission. Immunogenicity, the process of production of antibodies to biological agents, is fundamental to the evolution of loss of response to treatment in IBD patients. The presence of these antibodies in patients is linked to decreased serum drug levels and inhibited biological activity. However, immunogenicity rates exhibit significant variability across inflammatory disease states, immunoassay formats, and time periods. In this review, we aimed to elucidate the immunogenicity and immune mechanisms of antibody formation to biologics, the loss of therapy response, clinical results of biological treatment for IBD from systematic reviews and meta-analyses, as well as to summarize the most recent strategies for overcoming immunogenicity and approaches for managing treatment failure in IBD.

28 April 2020 in World Journal of Gastroenterology
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Journal Article
Closed access
Tsvetelina VelikovaTsvetelina Velikova
Tsvetelina Velikova
LMLyuba Miteva
Lyuba Miteva
NSNoyko Stanilov
Noyko Stanilov
ZSZoya Spassova
Zoya Spassova
SSSpaska Angelova Stanilova
Spaska Angelova Stanilova
The connection between inflammatory bowel disease (IBD) and colorectal cancer (CRC) is well-established, as persistent intestinal inflammation plays a substantial role in both disorders. Cytokines may further influence the inflammation and the carcinogenesis process. To compare cytokine patterns of active IBD patients with early and advanced CRC. Choosing a panel of cytokines crucial for Th17/Treg differentiation and behavior, in colon specimens, as mRNA biomarkers, and their serum protein levels. We found a significant difference between higher gene expression of FoxP3, TGFb1, IL-10, and IL-23, and approximately equal level of IL-6 in CRC patients in comparison with IBD patients. After stratification of CRC patients, we found a significant difference in FoxP3, IL-10, IL-23, and IL-17A mRNA in early cases compared to IBD, and IL-23 alone in advanced CRC. The protein levels of the cytokines were significantly higher in CRC patients compared to IBD patients. Our findings showed that IL-6 upregulation is essential for both IBD and CRC development until the upregulation of other Th17/Treg related genes (TGFb1, IL-10, IL-23, and transcription factor FoxP3) is a crucial primarily for CRC development. The significantly upregulated IL-6 could be a potential drug target for IBD and prevention of CRC development as well.