Kalina Tumangelova-Yuzeir

Dr. Kalina Tumangelova-Yuzeir


Research Focus & Metrics

Academic Career Length

3Years (2024-Present)

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

Representative Publications

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Verified
Journal Article
Open access
AYAdelina Danielova Yordanova
Adelina Danielova Yordanova
MIMariana Ivanova
Mariana Ivanova
KTKalina Tumangelova-Yuzeir
Kalina Tumangelova-Yuzeir
AAAlexander Krasimirov Angelov
Alexander Krasimirov Angelov
SKStanimir Kyurkchiev
Stanimir Kyurkchiev
EIEkaterina Ivanova-Todorova
Ekaterina Ivanova-Todorova
Autoimmune diseases represent a severe personal and healthcare problem that seeks novel therapeutic solutions. Mesenchymal stem cells (MSCs) are multipotent cells with interesting cell biology and promising therapeutic potential. The immunoregulatory effects of secretory factors produced by umbilical cord mesenchymal stem cells (UC-MSCs) were assessed on B lymphocytes from 17 patients with systemic lupus erythematosus (SLE), as defined by the 2019 European Alliance of Associations for Rheumatology (EULAR)/American College of Rheumatology (ACR) classification criteria for SLE, and 10 healthy volunteers (HVs). Peripheral blood mononuclear cells (PBMCs) from patients and HVs were cultured in a UC-MSC-conditioned medium (UC-MSCcm) and a control medium. Flow cytometry was used to detect the surface expression of CD80, CD86, BR3, CD40, PD-1, and HLA-DR on CD19+ B cells and assess the percentage of B cells in early and late apoptosis. An enzyme-linked immunosorbent assay (ELISA) quantified the production of BAFF, IDO, and PGE2 in PBMCs and UC-MSCs. Under UC-MSCcm influence, the percentage and mean fluorescence intensity (MFI) of CD19+BR3+ cells were reduced in both SLE patients and HVs. Regarding the effects of the MSC secretome on B cells in lupus patients, we observed a decrease in CD40 MFI and a reduced percentage of CD19+PD-1+ and CD19+HLA-DR+ cells. In contrast, in the B cells of healthy participants, we found an increased percentage of CD19+CD80+ cells and decreased CD80 MFI, along with a decrease in CD40 MFI and the percentage of CD19+PD-1+ cells. The UC-MSCcm had a minimal effect on B-cell apoptosis. The incubation of patients’ PBMCs with the UC-MSCcm increased PGE2 levels compared to the control medium. This study provides new insights into the impact of the MSC secretome on the key molecules involved in B-cell activation and antigen presentation and survival, potentially guiding the development of future SLE treatments.

7 February 2026 in Molecules
Verified
Journal Article
Open access
PDF file
YIYavor Lukanov Ivanov
Yavor Lukanov Ivanov
ZCZlatina Chengolova
Zlatina Chengolova
KTKalina Tumangelova-Yuzeir
Kalina Tumangelova-Yuzeir
AYAdelina Danielova Yordanova
Adelina Danielova Yordanova
EIEkaterina Ivanova-Todorova
Ekaterina Ivanova-Todorova
TGTzonka Ivanova Godjevargova
Tzonka Ivanova Godjevargova
The aim of this study was to obtain and characterize grape seed extract and to demonstrate its potential immunomodulatory properties in the autoimmune disease systemic lupus erythematosus (SLE). A Syrah grape seed extract was obtained using 70% aqueous ethanol, magnetic stirrer, 3 h. The obtained extracts were concentrated by vacuum evaporation and dryer at 40 °C. The total phenolic content (TPC), the total amount of flavonoids (TF) and procyanidins (PC), and the antioxidant (AO) capacity of the extract were determined by spectrophotometric methods. The individual composition of the extract was demonstrated by the high-performance liquid chromatography (HPLC) method. The effect of grape seed extract (GSE) on peripheral blood mononuclear cells (PBMC) from healthy donors and patients with SLE was studied to compare Th1 and Th2 subsets and their expression of key activation markers—CD25 and HLA-DR. PBMC were cultured in the presence or absence of GSE, and the effects on Th1 and Th2 cells were analyzed by flow cytometry. GSE treatment increased the proportion of Th1 cells in both healthy individuals and SLE patients. In addition, a significant upregulation of the late activation marker HLA-DR was observed on Th1 cells obtained from patients with systemic lupus erythematosus (SLE). No significant effects were found on Th2 cell populations. These findings indicate that GSE can stimulate Th1-mediated immune responses in SLE, proving its potential immunomodulatory properties beyond its known antioxidant effects.

25 March 2026 in Viruses
Verified
Journal Article
Open access
PDF file
TVTrifon Valkov
Trifon Valkov
DKDobroslav Kyurkchiev
Dobroslav Kyurkchiev
EKEkaterina Kurteva
Ekaterina Kurteva
KTKalina Tumangelova-Yuzeir
Kalina Tumangelova-Yuzeir
JAJeliazko Arabadjiev
Jeliazko Arabadjiev
YYYordanka Yamakova
Yordanka Yamakova
Background: Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is an autoimmune disorder frequently associated with ovarian teratomas in young women. Although infectious triggers have been proposed to contribute to immune activation, direct evidence linking viral presence within tumor tissue to disease pathogenesis remains limited. Case Presentation: An 18-year-old woman presented with acute neuropsychiatric symptoms, fever, gastrointestinal prodrome, and rapidly progressive behavioral disturbance progressing to encephalopathy. Cerebrospinal fluid and blood test results, together with clinical features, supported the diagnosis of anti-NMDAR encephalitis. Imaging identified an ovarian mass, and surgical resection was performed. Histopathology confirmed a mature teratoma containing neuroglial elements. Molecular analysis detected parvovirus B19 DNA within the resected teratomatous tissue. No systemic viremia or active central nervous system viral infection was identified. The patient received immunotherapy combined with tumor removal, with subsequent clinical improvement. Discussion: Ovarian teratomas remain a critical etiologic factor in anti-NMDAR encephalitis and mandate prompt surgical management. Detection of B19 viral DNA within teratomatous neuroglial tissue raises the hypothesis that viral persistence could enhance local immune activation and autoantibody generation. However, in this case polymerase chain reaction positivity does not indicate active infection, and the biological significance of this finding remains uncertain. Conclusions: This case documents rare detection of B19V DNA within an ovarian teratomatous tissue in anti-NMDAR encephalitis. The observation is hypothesis-generating rather than causal; established management priorities remain immunotherapy and tumor resection, and viral nucleic acid detection should be interpreted within the broader clinical context.