Tsvetelina Velikova

Sofia University "St. Kliment Ohridski" · Medical Faculty

BACKGROUND Hospitalized and severely ill coronavirus disease 2019 (COVID-19) patients necessitate prophylactic or therapeutic anticoagulation to minimize the risk of thrombosis at different sites. Life-threatening bleeding complications include spontaneous iliopsoas hematoma, peritoneal bleeding, and extra-abdominal manifestations such as intracran...

Intravenous administration of immunoglobulins has been routinely used for more than 60 years in clinical practice, developed initially as replacement therapy in immunodeficiency disorders. Today, the use of intravenous immunoglobulins (IVIGs) is embedded in the modern algorithms for the management of a few diseases, while in most cases, their appli...

Objectives: To compare pain intensity among individuals with idiopathic inflammatory myopathies (IIMs), other systemic autoimmune rheumatic diseases (AIRDs), and without rheumatic disease (wAIDs). Methods: Data were collected from the COVID-19 Vaccination in Autoimmune Diseases (COVAD) study, an international cross-sectional online survey, from...

Objective: COVID-19 vaccines have a favorable safety profile in patients with autoimmune rheumatic diseases (AIRDs) such as idiopathic inflammatory myopathies (IIMs), however hesitancy continues to persist among these patients.Therefore, we studied the prevalence, predictors, and reasons for hesitancy in patients with IIMs, other AIRDs, non-rheuma...

Objective COVID-19 vaccines have a favorable safety profile in patients with autoimmune rheumatic diseases (AIRDs) such as idiopathic inflammatory myopathies (IIMs), however hesitancy continues to persist among these patients. Therefore, we studied the prevalence, predictors, and reasons for hesitancy in patients with IIMs, other AIRDs, non-rheumat...

Objectives We aimed to compare the spectrum and severity of COVID-19 and vaccine breakthrough infections (BIs) among patients with IIMs, other systemic autoimmune and inflammatory diseases (SAIDs), and healthy controls (HCs). Methods This is a cross-sectional study with data from the COVAD study, a self-reported online global survey that collected...

Abstract: Basal cell carcinoma (BCC) is the most common skin cancer, and it makes up to 75% of non-melanocytic epithelial neoplasms. It usually affects sunexposed parts of the skin and 85% of all cases affect the head and the neck region. Rarely, BCC grows larger than 5cm in diameter – giant BCC. It’s locally invasive and grows deep into underlying...

The SARS-CoV-2 pandemic raised many challenges for all patients with chronic conditions and those with autoimmune diseases, both adults and children. Special attention is paid to their immunological status, concomitant diseases, and the need for immunosuppressive therapy. All of these factors may impact their COVID-19 course and outcome. COVID-19 v...

(1) Background: A number of studies have demonstrated the connection between develop- ing or exacerbating chronic respiratory diseases in adults and children. However, still, few studies focus on reducing exacerbations via immunomodulation. (2) Methods: In this pilot study, a total of 25 pediatric and adult patients with bronchial asthma (BA) and c...

Objective: To determine COVID-19 vaccine-related adverse events (AEs) in the seven-day post-vaccination period in patients with SLE versus autoimmune rheumatic diseases (AIRDs), non-rheumatic autoimmune diseases (nrAIDs), and healthy controls (HC). Methods: Data were captured through the COVID-19 Vaccination in Autoimmune Diseases (COVAD) questi...

Objective To determine COVID-19 vaccine-related adverse events (AEs) in the seven-day post-vaccination period in patients with SLE vs autoimmune rheumatic diseases (AIRDs), non-rheumatic autoimmune diseases (nrAIDs), and healthy controls (HC). Methods Data were captured through the COVID-19 Vaccination in Autoimmune Diseases (COVAD) questionnaire (...

We estimate the case fatality rate from COVID-19 with our method by age groups for three waves - September 2020 to January 2021 (wild type), February 2021 to May 2021 (alpha), and July 2021 to January 2022 (delta). We use linear regression with optimal lag with 21 days moving averaging to correct for reporting delays. We take the coefficient from t...

Objectives: The COVID-19 vaccination in autoimmune diseases (COVAD) study aimed to assess short-term COVID-19 vaccination-related adverse events (AEs) in rheumatoid arthritis (RA) patients. Methods: An online self-reported questionnaire (March-December 2021) was used to capture data related to COVID-19 vaccination-related AEs in RA, other autoim...

Objectives The COVID-19 vaccination in autoimmune diseases (COVAD) study aimed to assess short-term COVID-19 vaccination-related adverse events (AEs) in RA patients. Methods An online self-reported questionnaire (March–December 2021) was used to capture data related to COVID-19 vaccination-related AEs in RA, other autoimmune rheumatic diseases (AIR...

Objectives We aimed to compare the spectrum and severity of COVID-19 and vaccine breakthrough infections (BIs) among patients with IIMs, other systemic autoimmune and inflammatory diseases (SAIDs), and healthy controls (HCs). Methods This is a cross-sectional study with data from the COVAD study, a self-reported online global survey that collected...

Based on mucosal immunization to promote both mucosal and systemic immune responses, next-generation coronavirus disease 2019 (COVID-19) vaccines would be administered intranasally or orally. The goal of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines is to provide adequate immune protection and avoid severe disease and death....

The coronavirus disease 2019 (COVID-19) pandemic profoundly affected the management and treatment of patients with malignancies. Based on the progress reported in the literature, we reviewed the recommendations for treatment and vaccination in patients with gastrointestinal stromal tumor (GIST) during COVID-19. We focus on whether there is a risk a...

Managing a pandemic is a difficult task. Pandemics are part of the dynamics of nonlinear systems with multiple different interactive features that co-adapt to each other (such as humans, animals, and pathogens). The target of controlling such a nonlinear system is best achieved using the control system theory developed in engineering and applied in...

Diabetes mellitus is one of the most common comorbid conditions encountered in patients with severe acute respiratory syndrome coronavirus 2 infection accompanied by significantly increased mortality, prolonged hospital stay, and requirement of invasive mechanical ventilation. This review aims to present the effectiveness and safety profile of avai...

А particular group of children developed severe multisystem inflammation associated with current or recent SARS-CoV-2 infection or contact with a COVID-19 patient in the previous few weeks. The condition was defined as multisystem inflammatory syndrome (MIS) in children (MIS-C). As the definition of CDC and WHO is fast widely accepted, the lack of...

To control the pandemic, efficient vaccines must be applied to the population, including patients with autoimmune diseases. Therefore, one can expect that coronavirus disease 2019 (COVID-19) vaccines may influence the underlying autoimmune processes in these patients. Additionally, it is essential to understand whether COVID-19 vaccines would be ef...

It is well-known that the use of antibiotics, probiotics, and fecal microbiota transplantation (FMT) modulate gut microbiota, including favoring specific structures and functions or restoring the impaired microbiome. Although manipulation of the gut microbiome is attractive in the prevention and treatment of some associated diseases, there are some...

Background: The global pooled prevalence of gastroesophageal reflux disease (GORD) is approximately 14% and varies significantly according to the country. More population-based studies are needed in regions lacking epidemiological data on the prevalence of GORD, such as Eastern Europe, particularly Bulgaria. This current study aimed to evaluate th...

Vaccine hesitancy is considered a major barrier to achieving herd immunity against COVID-19. While multiple alternative and synergistic approaches including heterologous vaccination, booster doses, and antiviral drugs have been developed, equitable vaccine uptake remains the foremost strategy to manage pandemic. Although none of the currently appro...

Objectives The assessment of physical function is fundamental in the management of patients with idiopathic inflammatory myopathies (IIMs). We aimed to investigate the physical function of patients with IIMs compared with those with non-IIM autoimmune rheumatic diseases (AIRDs) utilizing Patient-Reported Outcome Measurement Information System (PROM...

Introduction/aims: We studied COVID-19 vaccination-related adverse events (ADEs) 7-days post-vaccination in patients with idiopathic inflammatory myopathies (IIMs) and other systemic autoimmune and inflammatory disorders (SAIDs). Methods: 7-day vaccine ADEs were collected in an international patient self-reported e-survey. Descriptive statistics...

Objectives COVID-19 vaccines have been proven to be safe in the healthy population. However, gaps remain in the evidence of their safety in patients with systemic autoimmune and inflammatory disorders (SAIDs). COVID-19 vaccination related adverse events (ADEs) in patients with SAIDs and healthy controls (HC) seven days post-vaccination were assesse...

Background: Evaluation of physical function is fundamental in the management of idiopathic inflammatory myopathies (IIMs). Patient-Reported Outcome Measurement Information System (PROMIS) is a National Institute of Health initiative established in 2004 to develop patient-reported outcome measures (PROMs) with improved validity and efficacy. PROMIS...

Background Significant gaps are present in the evidence of the spectrum and severity of COVID-19 infection in idiopathic inflammatory myopathies (IIM). IIM patients typically require immunosuppressive therapy, may have multiple disease sequelae, and frequent comorbidities, and thus may be more susceptible to severe COVID-19 infection and complicati...

Background COVID-19 vaccines have been proven to be safe and effective in the healthy population at large. However, significant gaps remain in the evidence of their safety in patients with systemic autoimmune and inflammatory disorders (SAIDs). Patients and rheumatologists have expressed concerns regarding vaccination triggered allergic reactions,...

Background Idiopathic inflammatory myopathies (IIM) are a rare, multisystem, heterogeneous diseases, and contribute to high psychological burden. The patients’ perception of physical health, deteriorating independence and social and environmental relationships may not always be a direct function of disease activity. To face with these aspects, seve...

Background Idiopathic inflammatory myopathies (IIM) are a group of heterogeneous autoimmune disorders with limited standardization of treatment protocols. Objectives To evaluate frequency and patterns of various treatments used for IIM based on disease subtype, world region, and organ involvement. Methods Cross-sectional data from the internation...

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 manageme...

Abstract: Introduction: The progression of allergy disorders is termed “atopic march.” Having one allergic disorder increases the likelihood of acquiring others. Asthma and food allergies often coexist. There are no thresholds for specific IgE (sIgE) associated with the presence of clinical symptoms. Each allergen shows a particular trend with age....

The newly identified strain of the Coronaviridae family called severe acute respiratory syndrome (SARS-CoV-2) recently became the most significant health threat for adults and children. Some main predictors of severe clinical course in patients with SARS-CoV-2 infection are age and concomitant health conditions. Therefore, the proper evaluation of...

Irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder whose pathogenesis is considered multifactorial, including abnormal gut motility, visceral hyperreactivity, psychological factors, disturbances in the brain-gut axis, leaky gut, oxidative stress, etc. We aimed to investigate serum levels of specific immunoglobulin E and...

We develop and apply our methodology to estimate the overburdening of hospitals in Bulgaria during the upcoming delta surge. We base our estimations on an exponential risk model from the UK. Still, the methodology is generally applicable to all risk models, depending on age. Our hypothesis is that during the delta wave in Bulgaria, the system exper...

Objective: Our aim was to analyze levels of proinflammatory biomarker interleukin-18 (IL-18) in healthy controls and patients with polycystic ovary syndrome (PCOS) focusing on its association with obesity, clinical, hormonal, and metabolic characteristics. Methods: Fifty-eight patients with PCOS were enrolled in the study fulfilling the Rotterda...

The pathogenesis of COVID-19 involves both humoral and cellular immunological responses, with cell-mediated immunity being discussed as the primary and most effective immune response to viral infection. It is supposed that COVID-19 vaccines also elicited effective cell immune response, and specifically IFNγ secreted by SARS-CoV-2-specific T-helper...

Objective: The unique mechanisms of immune regulation in the liver allow it to provide local and systemic immune tolerance to own and foreign antigens as a homeostatic condition via different T cell subsets and after liver transplantation (LT) while preserving an effective immune response against pathogens. Therefore, we aimed to analyze the Th17 a...

(1) Background: Several recent studies on the clinical value of spirometry indexes demonstrated high sensitivity of FEF25-75 as a marker of bronchial obstruction in asthmatics with normal baseline spirometry. Our study aims to evaluate the clinical value of maximal mid-expiratory flow in children with asthma. (2) Methods: For two years, 257 childre...

A few pieces of research exist about the protective titer against severe acute respiratory syndrome (SARS) coronavirus 2 (CoV-2; SARS-CoV-2) in monkeys and humans in which the protection could be shown as dose-dependent. Early studies supposed that higher levels of pre-existing neutralizing antibodies (Nabs) against SARS-CoV-2 can potentially corre...

Background: The endocannabinoid system is involved in the regulation of energy balance and ovarian function and may be implicated in the pathogenesis of polycystic ovary syndrome (PCOS). The purpose of the present study is to determine anandamide (AEA) levels in PCOS patients and controls and to analyze its association with metabolic and hormonal...

Introduction: Recent studies have shown that the intestinal microbiota can modulate certain systemic metabolic and immune responses, including liver graft function and the development of complications in patients after liver transplantation (LT). Akkermansia muciniphila (AKM) and Faecalibacterium prausnitzii (FAEP) are two of the most abundant gut...

Background. Significantly less is known about the immunoregulative cytokines, especially in allergic airway disease. This study aims to present the involvement of IL-35 and IL-10 in patients with allergic rhinitis (AR) and allergic bronchial asthma (BA). Methodology. The study comprised 71 patients-AR, patients with concomitant AR and mild atopic B...

Introduction: Diabetic foot disease is an advanced complication of diabetes mellitus, which is associated with severe invalidization and high mortality rate among affected people. Many factors are involved in its pathogenesis but not all of them are fully elucidated. Objectives: Adipose tissue and its hormones – adipokines, are related to diabetic...

The coronavirus disease-2019 (COVID-19) pandemic continues to be a cause of unprecedented global morbidity and mortality. Whilst COVID-19 vaccination has emerged as the only tangible solution to reducing poor clinical outcomes, vaccine hesitancy continues to be an obstacle to achieving high levels of vaccine uptake. This represents particular risk...

Abstract: Introduction: An atopic status assessment (skin prick test or specific immunoglobulin (sIgE)) in asthmatic children is considered a milestone in identifying potential risk factors and triggers provoking loss of asthma control and asthma exacerbation. Objective: The study aims to perform a comparative analysis of different laboratory metho...

Liver damage in severe acute respiratory coronavirus 2 infection occurs in patients with or without preexisting liver disorders, posing a significant complication and mortality risk. During coronavirus disease 2019 (COVID-19), abnormal liver function is typically observed. However, liver injury may occur because of the treatment as well. Ischemia,...

LRIOG - La Rivista Italiana di Ostetrica e Ginecologia. Volume 2021, Issue 4 (December 1, 2021): 51-59. p-ISSN: 1724-6776. e-ISSN: 1824-0283. DOI: 10.53146/lriog1202148 [Article in Italian]. Abstract: Since March 2020, the coronavirus disease 2019 (COVID-19) pandemic caused by the novel coronavirus SARS-CoV-2 (severe acute respiratory syndrome cor...

We present joint work on the epidemiology of the spread of Covid-19 across age groups showing the role of school measures and spread from 0-19 to higher age groups. We also show the probable counterintuitive effects of vaccination policy without targeting priority groups in order to decrease the spread. We show the cases of MIS-C in children from P...

Background/Purpose: Numerous Covid-19 vaccines have demonstrated efficacy and safety against SARS-CoV-2 in general population. Despite favorable adverse effect (ADRs) profile of vaccines, there have been concerns regarding activation of aberrant immune responses. Moreover, vaccine safety data in idiopathic inflammatory myopathies (IIM) and other sy...

Background: The role of transforming growth factor beta (TGF-β) signaling, including both the cytokine and their receptors, in the etiology of colorectal cancer (CRC) has been of particular interest lately. Aim: To investigate the association between promoter polymorphism in TGF-β receptor 2 TGF-ΒR2G[-875]A with a CRC risk in a cohort of Bulgari...

Pandemic risk management needs to include the patterns of evolution of the pathogens. In the case of COVID-19 pandemics, the B.1.617.2 variant which is dominant in Bulgaria since 21.07.2021, have been spreading most rapidly in the population 0-19 and more specifically from 10-19. The growth of cases is unprecedented and with the possibility to reac...

Abstract In liver transplant patients, solid tumors and post-transplant lymphoproliferative disorders have emerged as significant long-term mortality causes. In addition, it is assumed that de novo malignancy after liver transplantation (LT) is the second�leading cause of death after cardiovascular complications. Well-established risk factors for p...

MY LIFE AS A RESEARCHER AND EDUCATOR

Monitoring epidemic processes and the dynamics of the spread of infectious diseases is essential for predicting their distribution and effective planning in healthcare. The importance of studying seasonal trends in the spread of respiratory viral infections and the specific effects of non-pharmaceutical interventions in nationwide scales and the us...

SARS-CoV-2 infection may precede and cause various autoimmune and inflammatory diseases, including multisystem inflammatory syndrome in children (MIS-C). Therefore, we aimed to observe the clinical presentation and laboratory, instrumental and other constellations in children with MIS-C, including liver involvement. We present the outcomes from a s...