Borislav Ignatov

Dr. Borislav Ignatov


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

View All Publications
Verified
Journal Article
Open access
PDF file
Alexander Bozhidarov BlazhevAlexander Bozhidarov Blazhev
Alexander Bozhidarov Blazhev
Krasimir KostovKrasimir Kostov
Krasimir Kostov
BIBorislav Ignatov
Borislav Ignatov
TETsvetelina Eftimova
Tsvetelina Eftimova
TSTatyana Simeonova
Tatyana Simeonova
Svetla BlazhevaSvetla Blazheva
Svetla Blazheva
Chronic kidney disease (CKD) is associated with chronic inflammation and metabolic dysregulation. While endothelin-1 (ET-1) has been extensively studied, the role of endothelin-2 (ET-2) in CKD remains poorly understood. This cross-sectional study included 76 participants, 12 healthy controls and 64 CKD patients, stratified into three groups based on estimated glomerular filtration rate (eGFR): Group 1 (eGFR ≥ 90 mL/min/1.73 m2), Group 2 (eGFR 45–89 mL/min/1.73 m2), and Group 3 (eGFR 15–44 mL/min/1.73 m2). Serum concentrations of ET-1, ET-2, ET-3, uric acid (UA), and inflammatory markers (hsCRP and IL-6) were measured. ET-2 levels were significantly higher in the advanced CKD group (median 24.49 pg/mL) compared to controls (median 19.32 pg/mL; p = 0.030). No significant differences were observed for ET-1 or ET-3 across groups. ET-2 levels positively correlated with UA (rho = 0.243, p = 0.036), hsCRP (rho = 0.241, p = 0.039), and IL-6 (rho = 0.244, p = 0.038). These findings suggest that ET-2 may represent a potential biomarker reflecting metabolic and inflammatory dysregulation in CKD and highlight its possible relevance in disease severity assessment.

19 January 2025 in Biomedicines
Verified
Journal Article
Open access
PDF file
Krasimir KostovKrasimir Kostov
Krasimir Kostov
TSTatyana Simeonova
Tatyana Simeonova
BIBorislav Ignatov
Borislav Ignatov
TETsvetelina Eftimova
Tsvetelina Eftimova
Background: Chronic kidney disease (CKD) patients have an increased risk of cardiovascular disease (CVD), necessitating effective risk assessment methods. This study evaluates the calcium–phosphorus product (Ca × P) to estimated glomerular filtration rate (Ca × P/eGFR) ratio as a potential biomarker for predicting CV risk in pre-dialysis CKD patients. Methods: Eighty-four CKD patients in stages G1–G4, according to the KDIGO criteria, were classified into CVD (n = 43) and non-CVD (n = 41) groups. Biochemical parameters, including serum creatinine (SCr), blood urea nitrogen (BUN), calcium (Ca), inorganic phosphate (Pi), parathyroid hormone (PTH), alkaline phosphatase (ALP), Ca × P, eGFR, and the Ca × P/eGFR ratio, were measured and calculated. Statistical analyses were performed to identify predictors of CV risk and evaluate the diagnostic reliability of the Ca × P/eGFR ratio for predicting the risk. Results: Significant differences were observed in SCr, BUN, eGFR (p < 0.001), and the Ca × P/eGFR ratio (p = 0.007) between the groups. Regression analysis indicated the Ca × P/eGFR ratio as a significant CVD risk predictor (p = 0.012, OR = 1.206, 95% CI: 1.042–1.395). Receiver Operating Characteristic (ROC) curve analysis revealed an AUC of 0.751 (p < 0.001, 95% CI: 0.645–0.857), with a sensitivity and specificity of the method of 74.4% and 70.7%, respectively. Significant correlations were found between the Ca × P/eGFR ratio and SCr, BUN, UA, Ca, Pi, PTH, and ALP. Conclusions: The Ca × P/eGFR ratio may serve as a significant predictor of CVD risk in pre-dialysis CKD patients, suggesting that its integration into routine evaluations could enhance CV risk stratification and management.

2 May 2025 in Journal of IMAB – Annual Proceeding (Scientific Papers)
Verified
Journal Article
Closed access
TSTatyana Simeonova
Tatyana Simeonova
BIBorislav Ignatov
Borislav Ignatov
TETsvetelina Eftimova
Tsvetelina Eftimova
Krasimir KostovKrasimir Kostov
Krasimir Kostov
Vitamin K2 deficiency is associated with arterial calcification, which is a significant problem in patients with chronic kidney disease. It occurs more rapidly and earlier and appears to be an independent risk factor for higher morbidity and mortality. The ucMGP is considered to be a biomarker for indirect measurement of vitamin K2 status. Purpose: Our study aimed to measure ucMGP levels in patients at different stages of CKD and to evaluate its potential role as a biomarker of vitamin K2 status. Material/Methods: Sixty-seven patients aged between 31 – 87 years took part in the study. They were divided into groups according to glomerular filtration rate: Group I, with GFR ≥90 ml/min, Group II, with GFR 89 – 45 ml/min, Group III, with GFR 44 – 15 ml/min. Venous blood was tested for calcium, phosphate, creatinine and ucMGP. Results: Serum calcium and phosphate levels were within the reference ranges across all groups. Phosphate levels showed a progressive increase, with significantly lower levels in Group III. Mean ucMGP levels decreased from Group I to Group III, although these differences did not reach statistical significance. In Group I, women had significantly lower ucMGP concentrations compared to men. The incidence of CVD increased significantly with the progression of renal failure. Participants with CVD in Group I demonstrated significantly higher ucMGP concentrations compared to Group III. Conclusions: Uncarboxylated MGP can provide information about vitamin K2 and its carboxylation, but it is not a specific or reliable marker of vitamin K2 status.

17 March 2025 in Journal of Biomedical and Clinical Research
Verified
Journal Article
Open access
PDF file
BIBorislav Ignatov
Borislav Ignatov
TSTatyana Simeonova
Tatyana Simeonova
TETsvetelina Eftimova
Tsvetelina Eftimova
ADAnelia Dimitrova
Anelia Dimitrova
Krasimir KostovKrasimir Kostov
Krasimir Kostov
Introduction: Chronic kidney disease (CKD) patients are at high risk for cardiovascular disease, largely due to the presence of vascular calcification and its associated complications. Undercarboxylated matrix Gla protein (ucMGP), which inhibits vascular calcification, plays a crucial role in preventing this condition. Aim: Our study aimed to compare ucMGP levels in CKD patients with preserved and reduced renal function and to evaluate its role as a biomarker for cardiovascular risk. Materials and methods: We studied 84 patients with predialysis CKD. They were divided into two groups according to the kidney function: Group I – patients with preserved renal function (GFR ≥ 90 ml/min) and Group II – patients with mild to severely decreased renal function (GFR between 15 and 89 ml/min). Blood samples were analyzed using the Cobas E 311 automated analyzer and the ucMGP levels were measured using an ELISA kit from Abbexa, UK. Results: In Group I, CVD patients had significantly higher inorganic phosphates, blood urea nitrogen and serum creatinine. In Group II, CVD patients had significantly higher ucMGP concentrations. UcMGP levels were associated with age and CVD in Group II and highly correlated with inorganic phosphate and serum creatinine levels in Group I. Conclusions: UcMGP levels show a significant increase in CKD patients with CVD and are strongly connected to various renal function indices, indicating its potential as a biomarker for cardiovascular risk assessment.

6 August 2026 in Journal of IMAB – Annual Proceeding (Scientific Papers)
Verified
Journal Article
Closed access
BIBorislav Ignatov
Borislav Ignatov
Krasimir KostovKrasimir Kostov
Krasimir Kostov
TETsvetelina Eftimova
Tsvetelina Eftimova
Alexander Bozhidarov BlazhevAlexander Bozhidarov Blazhev
Alexander Bozhidarov Blazhev
TSTatyana Simeonova
Tatyana Simeonova
Chronic kidney disease (CKD) affects over 10% of the global population, posing significant challenges due to its asymptomatic nature in early stages and progressive deterioration of renal function. The identification of reliable biomarkers for early diagnosis and monitoring of disease progression is crucial for improving prognosis and treatment. Neutrophil gelatinase-associated lipocalin (NGAL) is a promising candidate, already validated as a marker for acute kidney injury. Purpose: This study aimed to evaluate the potential of serum NGAL levels as a biomarker for diagnosis and monitoring the progression of CKD. Material/Methods: Seventy-one adult Caucasian patients at CKD stages G1–G4 according to the KDIGO criteria were divided into three groups: Group 1 (eGFR ≥90 mL/min/1.73m²), Group 2 (eGFR 45–89 mL/min/1.73m²), and Group 3 (eGFR 15–44 mL/min/1.73m²). Blood samples were collected and analyzed via standard biochemical and immunological techniques. Serum NGAL levels were measured using ELISA. Results: NGAL levels increased significantly with disease progression and strongly correlated with declining eGFR. Higher NGAL levels were linked to elevated serum creatinine and inflammatory markers, indicating progressive damage to the kidney tissue against the backdrop of persistent systemic inflammation. Conclusions: As a biomarker, NGAL has significant potential for identifying and monitoring kidney damage. Its application in clinical settings could complement and improve existing methods for diagnosing and observing CKD.

29 July 2025 in Preprints.org
Verified
Preprint
Open access
PDF file
BIBorislav Ignatov
Borislav Ignatov
Krasimir KostovKrasimir Kostov
Krasimir Kostov
TETsvetelina Eftimova
Tsvetelina Eftimova
Alexander Bozhidarov BlazhevAlexander Bozhidarov Blazhev
Alexander Bozhidarov Blazhev
TSTatyana Simeonova
Tatyana Simeonova
Background: The identification of reliable biomarkers for early diagnosis and monitoring of chronic kidney disease (CKD) progression is crucial for improving prognosis and treatment. Neutrophil gelatinase-associated lipocalin (NGAL) is a promising candidate, already validated as a marker for acute kidney injury. This study evaluates NGAL's potential as a biomarker for early diagnosis and monitoring the progression of CKD. Seventy-one patients at CKD stages G1–G4 according to the KDIGO criteria were divided into three groups: Group 1 (eGFR ≥90 mL/min/1.73m²), Group 2 (eGFR 45–89 mL/min/1.73m²), and Group 3 (eGFR 15–44 mL/min/1.73m²). Blood samples were collected and analyzed via standard biochemical and immunological techniques. Serum NGAL levels were measured using ELISA. Results: NGAL levels increased significantly with disease progression and strongly correlated with declining eGFR. Higher NGAL levels were linked to elevated serum creatinine and inflammatory markers, indicating progressive damage to the kidney tissue against the backdrop of persistent systemic inflammation. Conclusions: NGAL demonstrates considerable potential as a biomarker for early detection and monitoring of kidney damage progression. Its use in clinical practice could enrich the traditional methods of diagnosis and monitoring of patients with CKD.