Military Medical Academy
Recent publications
In this study, we investigated the potential association between the severity of COVID-19 (coronavirus disease 2019) and nasopharyngeal viral loads or serum antibody levels and evaluate the temporal dynamics of antibodies against SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2). Using ELISA (enzyme-linked immunosorbent assay), we determined the presence of IgA, IgM and IgG antibodies in 450 serum samples from 122 patients for a period of 9 months after disease onset. Viral burden was quantified by RT-PCR (reverse transcription polymerase chain reaction) in 270 nasopharyngeal swab samples from 122 patients for a period of 4 weeks after the onset of the symptoms. Higher antibody values were generally seen in patients with moderate and severe disease compared to patients with mild COVID-19. Significant differences were established in IgA and IgG antibody levels at weeks 3–4 and 5–13 after the disease onset. In all severity groups, seroconversion rates were high and a similar pattern was observed with IgM antibodies quickly decreasing after reaching peak levels and IgA and IgG antibodies persisting at high values up to 9 months. The mean viral loads were higher in the mild group during the first 2 weeks and in the moderate and severe groups later on. However, the differences were not statistically significant. The IgA and IgG antibody response was significantly stronger in patients with moderate/severe disease around the time of peak antibody production as well as in vaccinated patients. No definitive association between viral load levels and the severity of COVID-19 was observed.
1) Background: The study presents results from an investigation of cognitive impairment in patients hospitalized in the first psychiatric clinic in Bulgaria to treat patients with COVID-19 during the pandemic period between 2020 and 2022. One hundred and twenty patients who had recovered from acute COVID-19 infection (up to 12 weeks ago) and had no previous history of cognitive impairment participated in the study. In 23 of them (19.17%), disturbance of cognitive functioning was observed. (2) Methods: All 23 patients underwent neuropsychological (Luria's test, Platonov's Maze test, MMSE, Boston Naming test) and neuroimaging examinations. Only seven of them had evidence of cortical atrophy on CT/MRI images. The most significantly demonstrative image of one of those patients is presented. (3) Results: The neuropsychological testing results of both groups show a certain decrease in fixation and memory retention as well as in the range, concentration, distribution and switching of attention. Deviations from the norm on the MMSE, as well as on the Boston Naming Test, were found in the group of patients with cortical atrophy (mild to moderate aphasia). Neuroprotective agents such as Citicoline, Piracetam and Memantine were prescribed to the patients with evident cortical atrophy. After 3 months, positive results of the neuropsychological examination were reported in both groups. (4) Conclusions: Although there are limited data on the benefit of prescribing pro-cognitive agents in the post-COVID period, our clinical experience suggests that it might be useful in the recovery process from the infection's consequences on cognition for patients with brain pathology.
The COVID-19 pandemic has posed a significant threat to public health worldwide. While some patients experience only mild symptoms or no symptoms at all, others develop severe illness, which can lead to death. The host immune response is believed to play a crucial role in determining disease severity. In this study, we investigated the involvement of CD74 and D-DT in COVID-19 patients with different disease severities, by employing an in silico analysis of a publicly available transcriptomic dataset and by measuring their serum levels by ELISA. Our results showed a significant increase in MIF levels in PBMCs from COVID-19 patients, as well as a significant increase in the D-DT levels in PBMCs. However, we observed no modulation in the serum levels of D-DT. We also observed a concordant reduction in the serum levels and PBMCs expression levels of CD74. Furthermore, we found a negative correlation between CD74 serum levels and IL-13. In conclusion, our study sheds light on the involvement of CD74 and D-DT in COVID-19, with potential implications for disease severity and treatment. Further studies are needed to fully elucidate the mechanisms underlying these observations and to explore the potential therapeutic value of targeting CD74 and IL-13 in COVID-19.
In recent years, hepatitis E virus (HEV) infection has been found to be widespread among different animal species worldwide. In Bulgaria, high HEV seropositivity was found among pigs (60.3%), wild boars (40.8%), and East Balkan swine (82.5%). The aim of the present study was to establish the seroprevalence of HEV among dogs, cats, horses, cattle, sheep, and goats in Bulgaria. In total, 720 serum samples from six animal species were randomly collected: dogs—90 samples; cats—90; horses—180; cattle—180; sheep—90; and goats—90. The serum samples were collected from seven districts of the country: Burgas, Kardzhali, Pazardzhik, Plovdiv, Sliven, Smolyan, and Stara Zagora. The animal serum samples were tested for HEV antibodies using the commercial Wantai HEV-Ab ELISA kit (Beijing, China). The overall HEV seroprevalence among different animal species from Bulgaria was as follows: dogs—21.1%; cats—17.7%; horses—8.3%; cattle—7.7%; sheep—32.2%; and goats—24.4%. We found the lowest overall HEV seropositivity in Plovdiv district (6.2%; 4/64; p = 0.203) and Smolyan district (8.8%; 4/45; p = 0.129), vs. the highest in Pazardzhik district (21.6%; 29/134; p = 0.024) and Burgas district (28.8%; 26/90; p = 0.062). To the best of our knowledge, this is the first serological evidence of HEV infection in dogs, cats, horses, cattle, sheep, and goats from Bulgaria. We found high HEV seropositivity in small ruminants (sheep and goats), moderate seropositivity in pets (dogs and cats), and a low level of seropositivity in large animals (horses and cattle). Previous Bulgarian studies and the results of this research show that HEV infection is widespread among animals in our country. In this regard, the Bulgarian health authorities must carry out increased surveillance and control of HEV infection among animals in Bulgaria.
Hepatitis E virus (HEV) is one of the leading causes of acute viral hepatitis. Transmission of HEV mainly occurs via the fecal-oral route (ingesting contaminated water or food) or by contact with infected animals and their raw meat products. Some animals, such as pigs, wild boars, sheep, goats, rabbits, camels, rats, etc., are natural reservoirs of HEV, which places people in close contact with them at increased risk of HEV disease. Although hepatitis E is a self-limiting infection, it could also lead to severe illness, particularly among pregnant women, or chronic infection in immunocompromised people. A growing number of studies point out that HEV can be classified as a re-emerging virus in developed countries. Preventative efforts are needed to reduce the incidence of acute and chronic hepatitis E in non-endemic and endemic countries. There is a recombinant HEV vaccine, but it is approved for use and commercially available only in China and Pakistan. However, further studies are needed to demonstrate the necessity of applying a preventive vaccine and to create conditions for reducing the spread of HEV. This review emphasizes the hepatitis E virus and its importance for public health in Europe, the methods of virus transmission and treatment, and summarizes the latest studies on HEV vaccine development.
The public health significance of hepatitis E is very important. According to the World Health Organization (WHO), there are an estimated 20 million hepatitis E virus (HEV) infections worldwide every year, leading to an estimated 3.3 million symptomatic cases of hepatitis E. The WHO estimates that HEV infection caused approximately 44,000 deaths in 2015, which represents 3.3% of mortality rates due to viral hepatitis.
Dietary imbalance and overeating can lead to an increasingly widespread disease - obesity. Aesthetic considerations aside, obesity is defined as an excess of adipose tissue that can lead to serious health problems and can predispose to a number of pathological changes and clinical diseases, including diabetes; hypertension; atherosclerosis; coronary artery disease and stroke; obstructive sleep apnea; depression; weight-related arthropathies and endometrial and breast cancer. A body weight 20% above ideal for age, gender and height is a severe health risk. Bariatric surgery is a set of surgical methods to treat morbid obesity when other treatments such as diet, increased physical activity, behavioral changes and drugs have failed. The two most common procedures currently used are sleeve gastrectomy and gastric bypass. This procedure has gained popularity recently and is generally considered safe and effective. Although current data show that perioperative mortality is low and better control of comorbidities and short-term complications is achieved, more randomized trials are needed to evaluate the long-term outcomes of bariatric procedures. This review aims to synthesize and summarize the growing evidence on the long-term effectiveness, outcomes and complications of bariatric surgery.
The problems with lymphangiomas in general stem from the fact that on the one hand they most often show an atypical clinical picture, and on the other hand their localization does not always allow the desired complete surgical removal. Lymphangiomas are rare and benign tumors of the lymphatic vessels. In the higher percentage of cases, they are defined as congenital malformations. The acquired type can manifest due to a variety of external factors, resulting in a benign distinct lesion, which can often be mistaken for another benign or malignant one. Although benign and even surgically treated , the recurrence rate is high. The pathogenesis of these tumours is unclear and is presumed to be due to an error in the fetal/ embryonal development. Nosologically, these lesions belong to the group of so-called low flow lesions. Within the framework of their differentiation, it is important to distinguish them from hemangiomas and venous malformations, as although overlapping to some extent, at times-therapeutic options differ. This differentiation is most adequately accomplished by the application of MRI and Doppler, necessarily accompanied by histopathologic verification of the lesion. Spontaneous regression, although rare, occurs in up to 6% of cases. Surgical removal remains the safest method of treatment to date, and according to the literature this is possible in only 18 to 50% of cases. Often, however, the atypical clinical presentation of some of the lesions could be confusing for clinicians and could be the reason for prolonged and unsuccessful conservative or semi-invasive therapy. We present a 23-year-old patient with a history of complaints of more than 15 years in the form of itching, burning, and discomfort in the left foot area. The finding was treated under the diagnosis of viral warts with variable results and subsequent achievement of short-term remissions for no more than 5-6 months. Due to an increase in pain symptomatology and an increase in the size of the lesion after the last cryotherapy, a skin biopsy was taken to confirm the diagnosis of lymphangioma. During hospitalization, the patient underwent MRI/Doppler of the vessels to determine the depth of infiltration and the presence/ exclusion of communication to larger vascular formations for preoperative planning. Surgery was performed with secondary wound healing resulting in a favourable outcome.
Background: The expression of programmed cell death ligand protein (PD-L1) is weakly investigated in non-tumoral and inflammatory prostatic pathology. The diagnosis of granulomatous prostatitis (GP) rests on the recognition of localized or diffuse epithelioid granulomatous inflammation in prostatic tissue which is frequently difficult by conventional histological observation alone. PD-L1 expression in GP is not well studied so far. Methods: We studied PD-L1 expression in 17 GP cases (9 nonspecific GP, 5 Bacillus Calmette-Guérin induced prostatitis, 1 prostatic tuberculosis, and 3 cases of postsurgical prostatic granulomas). The control group included 10 radical prostatectomies of patients with high Gleason score prostate adenocarcinoma (PCa) and National Institutes of Health-category IV prostatitis (high-grade histologic prostatitis; HG-HP). Results: All of the GP cases showed easily visible strong membranous PD-L1 expression (high levels of combined positive score) in localized and diffuse epithelioid granulomatous prostatic inflammation. None of the control cases showed the presence of significant PD-L1 expression in inflammatory infiltrates in HG-HP, tumor parenchyma, and stroma in PCa. Conclusions: The study presents the first attempt to examine PD-L1 expression in GP. Granulomatous inflammation in GP is easily identified when stained with PD-L1.
Introduction: The acute viral hepatitis was one of the most common conditions in daily clinical practice varying in different parts of the world. The aim of the present study was to perform a comparative analysis on clinical characteristics among patients with acute hepatitis A virus (HAV) infection and patients with acute hepatitis E virus (HEV) infection admitted to the Military Medical Academy (MMA), Sofia, Bulgaria. Methods: A retrospective study was performed at MMA, between 1 January 2016 and 31 December 2021. The etiological diagnosis was confirmed by enzyme-linked immunosorbent assay (ELISA) HAV/HEV IgM serology assays. Results: The current survey included 231 patients with mean age 45.11 ± 16.08 years (95% confidence interval: 43.04-47.19). According to the case definition, inclusion and exclusion criteria, persons were divided into two groups: patients with acute HAV infection (68.4%; 158/231) and patients with acute HEV infection (31.6%; 73/231). Males with HEV had 3.091 times the odds of comorbidity "hypertension" than males with HAV (p = 0.032). There were almost equal odds of increased ALT (odds ratio = 0.999; p = 0.003) in men with HEV and men with HAV. Females with HEV had 5.161 times the odds of comorbidity "hypertension" compared with females with HAV (p = 0.049). We found almost equal odds for elevated ALT in women with HEV and women with HAV (OR = 0.999; p = 0.025). In the non-elderly group (<60-year-old), HEV individuals had 4.544 and 10.560 times the odds of comorbidities "hypertension" and "cardiovascular diseases" compared with HAV patients (p < 0.05). We found almost equal odds for elevated ALT in HEV patients and HAV participants (OR = 0.998; p = 0.002). Conclusion: The results from the current study may support the physicians daily care for patients with acute HAV and acute HEV.
Severe infections due to highly virulent and resistant Staphylococcus aureus pose a serious health threat in Bulgaria and worldwide. The purpose of this study was to explore the clonal spread of recent clinically significant methicillin-susceptible S. aureus (MSSA) isolates from inpatients and outpatients treated in three university hospitals in Sofia, Bulgaria, during the period 2016-2020 and evaluate the relationship between their molecular epidemiology, virulence profiling, and antimicrobial resistance. A total of 85 isolates (invasive and noninvasive) were studied using RAPD analysis. Ten major clusters (A-K) were identified. The first major cluster A (31.8%) was found to be predominant during 2016 and 2017 and was widespread in two hospitals, unlike its case in the following years, when it was found to be replaced by newer cluster groups. All MSSA members of the second most common cluster F (11.8%) were recovered from the Military Medical Academy, mainly during 2018-2020, and were determined to be susceptible to all other groups of antimicrobials, except for penicillins without inhibitors because they harboured the blaZ gene. The newer cluster I, with 9.4% of the isolates absent in 2016-2017, showed significantly higher virulence and macrolide resistance (42.9%) due to ermB and ermC. All the isolated MSSA in groups F and I were nosocomial and mostly invasive. In conclusion, this 5-year study demonstrates the molecular epidemiology of MSSA infections in three Bulgarian hospitals. Findings can be helpful for the understanding of staphylococcal infection distribution in hospital settings and their prevention.
The worldwide distribution of the HBV infection has usually been estimated by the prevalence of hepatitis B surface antigen (HBsAg) among the general population. Total antibodies for hepatitis B core antigen (anti-HBc) are the most important diagnostic marker for proving prior exposure to HBV. Aim The aim of this study was to determine the prevalence of Hepatitis B virus (HBV) infection among Bulgarian population. Reliable epidemiologic data is needed to estimate the prevalence of Hepatitis B in order to determine the actual burden of the infection and to plan prevention and control measures. Materials and methods A total of 2140 serum samples were tested for major serological markers of HBV (HBsAg and anti-HBc) for a period of two years (2018-2019). Results We established an intermediate prevalence of HBsAg (5.1%) and high prevalence of anti-HBc (27%) among HBsAg negative individuals. Conclusion In conclusion, the prevalence of Hepatitis B is much higher among those born before the introduction of universal hepatitis B vaccination in Bulgaria (1992).
The pathogenesis of lichen planus and lichenoid-type reactions remains shrouded in mystery to this day, precisely because of the inability to perform acute/specific tests for reproduction of a particular type of reaction (in this case lichenoid) in order to prove a causal relationship. Nevertheless, the concept of molecular mimicry/antigen mimicry as a possible important pathogenetic inducer for lichen planus and lichenoid-type reactions, is increasingly becoming a topic of discussion and remains more than relevant at present. Disturbances in the integrity of tissue homeostasis- in one form or another, in fact, become a powerful generator of cross-mediated immunity, possibly directed at tissue-localized structures/structural elements/proteins or amino acids. The observation and reporting of this kind of disorders (even in the absence of the mentioned tests), as well as their parallel manifestation with a disease such as lichen planus (or lichenoid-type reaction), has led over the years to the validation of the now universal belief that the disease is multifactorially determined. And the causes of disruption of this integrity can be both external- infectious, meicamentous as well as internal- tumoral, paraneoplastic, etc. Medication induction or triggering of lichen planus by beta blockers has been observed and reported frequently over the years, and the clinical picture can vary and be extremely heterogeneous. We describe the first case in the world literature of a lichen planus after nebivolol administration that developed in the strictly restricted area of the glans penis. According to a reference in the medical literature, this is also the second case in the world literature of penile localized lichen planus after beta blocker intake. The other analogous one was recorded and described back in 1991 after propranolol intake.
Subungual lesions present a serious challenge for clinicians. The following factors can cause certain problems in interpreting the data: 1) Changes in lesion morphology over time: It may indicate the presence of a malignant lesion (increased pigmentation over time and lack of distal growth) but may actually be a benign lesion (chronic persistent subungual hematoma). 2) Patient's medical history can be misleading or difficult to verify, especially in problematic patients, or those with mental health problems or communication disorders (e.g., Asperger's syndrome, autism, schizoid psychosis, etc.). 3) The morphology of the lesion itself can be difficult to determine in the presence of simultaneously overlapping lesions. These patient dilemmas primarily concern the differentiation between subungual hematomas from subungual melanomas. The clinicians's concerns are based on the potential for metastasis and the risk of significantly worse prognosis for patients affected by nail biopsy. We present a 19-year-old patient with a subungual pigmented lesion with a clinical/dermatoscopic suspicion for subungual melanoma. Primary complaints for about 3-4 months. Intensified pigmentation and increase in size within two months led to a partial surgical resection of the nail plate and nail bed, followed by adaptation of the wound edges with single interrupted sutures. The histopathological finding was indicative of a subungual hematoma located above a focal melanocytic hyperplasia of the nail bed, clear resection lines. After a literature review, we believe that this is the first case of a patient with simultaneously present subungual benign focal melanocytic hyperplasia overlapping with a chronic persistent subungual hematoma.
The advent of biologic disease-modifying antirheumatic drugs has dramatically changed the comprehensions of treatment and long-term prognosis in patients with rheumatoid arthritis. The potent therapeutic results can only be achieved if the patients adhere to prescribed medications. The objective of this study was to estimate the impact of age, gender, duration of the disease, concomitant Methotrexate therapy, prior exposure to biologic agents, disease activity, functional capacity, and health-related quality of life on adherence to biologic treatment among Bulgarian population with rheumatoid arthritis. This was a retrospective observational cohort study that included 179 patients. At the baseline visit and subsequent follow-up assessments at 6, 12, 24 and 36 months, patients were interviewed by a physician and underwent physical examinations. We monitored the changes in disease activity, functional capacity and health-related quality of life on each time point. Univariate and multivariate binary logistic regression was used to determine the prognostic value of possible predictors of treatment adherence. Our findings showed that only DAS28 score [odd ratio (OR) = 1.174; 95% CI 1.74–2.362] and HAQ score (OR 2.803; 95% CI 1.428–5.503) remained significant for the treatment adherence throughout the study period. The adherence to the biologic disease-modifying anti-rheumatic drugs among Bulgarian patients with rheumatoid arthritis is suboptimal. A multifaceted and comprehensive knowledge of the influencing factors can be useful for the development of different strategies that can improve treatment adherence.
Immune memory to SARS-CoV-2 is key for establishing herd immunity and limiting the spread of the virus. The duration and qualities of T-cell-mediated protection in the settings of constantly evolving pathogens remain an open question. We conducted a cross-sectional study of SARS-CoV-2-specific CD4+ and CD8+ T-cell responses at several time points over 18 months (30–750 days) post mild/moderate infection with the aim to identify suitable methods and biomarkers for evaluation of long-term T-cell memory in peripheral blood. Included were 107 samples from 95 donors infected during the periods 03/2020–07/2021 and 09/2021–03/2022, coinciding with the prevalence of B.1.1.7 (alpha) and B.1.617.2 (delta) variants in Bulgaria. SARS-CoV-2-specific IFNγ+ T cells were measured in ELISpot in parallel with flow cytometry detection of AIM+ total and stem cell-like memory (TSCM) CD4+ and CD8+ T cells after in vitro stimulation with peptide pools corresponding to the original and delta variants. We show that, unlike IFNγ+ T cells, AIM+ virus-specific CD4+ and CD8+ TSCM are more adequate markers of T cell memory, even beyond 18 months post-infection. In the settings of circulating and evolving viruses, CD8+ TSCM is remarkably stable, back-differentiated into effectors, and delivers immediate protection, regardless of the initial priming strain.
Oxidative stress and the albumin oxidized form can lead to hypoalbuminemia, which is a predisposing factor for reduced treatment effectiveness and an increased mortality rate in severe COVID-19 patients. The aim of the study is to evaluate the application of free radical 3-Maleimido-PROXYL and SDSL-EPR spectroscopy in the in vitro determination of ox/red HSA in serum samples from patients with SARS-CoV-2 infection. Venous blood was collected from patients intubated (pO2 < 90%) with a positive PCR test for SARS-CoV-2 and controls. At the 120th minute after the incubation of the serum samples from both groups with the 3-Maleimido-PROXYL, the EPR measurement was started. The high levels of free radicals were determined through the nitroxide radical TEMPOL, which probably led to increased oxidation of HSA and hypoalbuminemia in severe COVID-19. The double-integrated spectra of 3-Maleimido-PROXYL radical showed a low degree of connectivity due to high levels of oxidized albumin in COVID-19 patients. The low concentrations of reduced albumin in serum samples partially inhibit spin-label rotation, with Amax values and ΔH0 spectral parameters comparable to those of 3-Maleimido-PROXYL/DMSO. Based on the obtained results, we suggest that the stable nitroxide radical 3-Maleimido-PROXYL can be successfully used as a marker to study oxidized albumin levels in COVID-19.
Genital melanocytic lesions can be quite difficult to distinguish due to the close proximity of the clinical findings. Melanocytic lesions, especially in delicate anatomical locations such as the vulva, penis, mons pubis etc, are even more challenging to diagnose. The patients may delay physical examinations due to anxiety or discomfort from the location of the lesion. In terms of therapy options, the surgical approach is not always the preferred one, but it is the one that could lead to a definitive solution to the problem. A limited number of studies in the medical literature do not exclude the fact that atypical nevi of genital type could also be considered as melanoma precursors. Single case reports have identified atypical genital nevi of the labia majora as a risk factor for genital melanoma development. Lesions that occupy a larger area than the labia majora and extend into the areas around them are particularly problematic. Precisely because of this fact, the result of a single biopsy could be false and misleading. Therefore, careful physical and repeated preoperative histological examinations are mandatory. Mechanical irritation in the genital area, and in particular in the labia majora region, is an additional reason for choosing the surgical-reconstructive therapeutic option. We present a 13-year-old female with a progressive “kissing” divided nevus from genital type (AMNGT) , located in the area of the vulva and labia majora, extending to the mucosa. A biopsy was taken in order to rule out malignancy. Immunohistochemistry was performed with specific melanocyte markers S-100, HMB-45 and SOX confirming the benign origin of the lesion. A diagnosis of atypical melanocytic nevus of genital type (AMNGT) was made. For prevention a surgical excision was advised but later on declined by the patient’s parents. Further close observation of the lesion was recommended.
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143 members
Lyubina Vesselinova
  • First Clinic of P&RM
Nikola Vladov
  • HPB and transplant surgery
Vassil Mihaylov
  • HPB and Transplant Surgery
Iliya Saltirov
  • Urology and Nephrology
Rumena Petkova
  • Clinic of Nephrology
Sofia, Bulgaria