Tijana Veljkovic

Dr. Tijana Veljkovic


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
PDF file
MMMladen Maksic
Mladen Maksic
Irfan CorovicIrfan Corovic
Irfan Corovic
TVTijana Veljkovic
Tijana Veljkovic
JZJelena Zivic
Jelena Zivic
MZMilos Z Zivic
Milos Z Zivic
Miloš NikolićMiloš Nikolić
Miloš Nikolić
The emergence of anti-TNF agents has revolutionized the management of inflammatory bowel disease, yet a significant proportion of patients experience primary non-response or secondary loss of response due to immunogenicity. As the field of precision medicine advances, genetic predictors such as human leukocyte antigen (HLA) variants are gaining increasing attention. This review provides a comprehensive synthesis of current evidence on the role of HLA genotypes in inflammatory bowel disease susceptibility and disease behavior, with a focus on their mechanistic and clinical relevance in anti-TNF therapy. Special emphasis is placed on HLA-DQA1*05, a validated predictor of anti-drug antibody formation and reduced therapeutic durability. We explore the immunological basis of HLA-mediated immunogenicity, summarize pharmacogenetic and biomarker findings, and discuss how HLA typing may be integrated into treatment algorithms to improve patient stratification and long-term outcomes. As immunogenetics continues to inform clinical decision-making, understanding the interplay between HLA polymorphisms and therapeutic response offers new opportunities for biomarker-guided, personalized care in inflammatory bowel disease.

Verified
Journal Article
Open access
PDF file
MMMladen Maksic
Mladen Maksic
Irfan CorovicIrfan Corovic
Irfan Corovic
ISIsidora Stanisavljević
Isidora Stanisavljević
DRDušan Radojević
Dušan Radojević
TVTijana Veljkovic
Tijana Veljkovic
IJIvan Jovanovic
Ivan Jovanovic
Heyde syndrome, marked by aortic stenosis, gastrointestinal bleeding from angiodysplasia, and acquired von Willebrand syndrome, is often underreported. Shear stress from a narrowed aortic valve degrades von Willebrand factor multimers, leading to angiodysplasia formation and von Willebrand factor deficiency. This case report aims to raise clinician awareness of Heyde syndrome, its complexity, and the need for a multidisciplinary approach. We present a 75-year-old man with aortic stenosis, gastrointestinal bleeding from angiodysplasia, and acquired von Willebrand syndrome type 2A. The patient was successfully treated with argon plasma coagulation and blood transfusions. He declined further treatment for aortic stenosis but was in good overall health with improved laboratory results during follow-up. Additionally, we provide a comprehensive review of the molecular mechanisms involved in the development of this syndrome, discuss current diagnostic and treatment approaches, and offer future perspectives for further research on this topic.

12 May 2025 in Diagnostics
Verified
Journal Article
Open access
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MCMilica Cekerevac
Milica Cekerevac
JPJelena - Pantovic
Jelena - Pantovic
MMMarija Medovic
Marija Medovic
NINebojša Igrutinović
Nebojša Igrutinović
SKSanja Milan Knezevic
Sanja Milan Knezevic
RMRaša H. Medovic
Raša H. Medovic
Background/Objectives: Chronic idiopathic thrombocytopenic purpura (chITP) is an autoimmune disease which develops in 10–30% of patients with newly diagnosed idiopathic thrombocytopenic purpura (ndITP). It is defined as thrombocytopenia which lasts longer than 12 months, with extremely diverse clinical expressions. The aim is to present the most significant clinical and laboratory characteristics of children with chITP. Methods: This is retrospective, observational research, which included children between 2–18 years with chITP who were treated in the Republic of Serbia for 25 years. We analyzed clinical data from personal and family medical histories and different laboratory analyses. Results: The total number of respondents was 152, with female predominance (F:M = 1.27:1) and mild predominance of adolescents. Of the patients, 15% were asymptomatic, but 15% had periodically life-threatening bleeding. Transfusion was not required for 70% of patients. Thirty-five percent of patients had chITP alone, and 45% had high titer levels of autoantibodies. The most frequent comorbidity was Hashimoto thyroiditis (15%). The same percentage (45%) of family members were reported with and without autoimmune diseases. Twenty-five percent of patients were resistant to initial therapy. Helicobacter pylori was detected in 20%, 70% had higher levels of lactate dehydrogenase (LDH), three patients had sufficient serum vitamin D levels, splenomegaly was found in 25%, and accessory spleen in 14% of patients. Around 50% of patients had a platelet count between 20–50 × 10⁹/L, and 40% below 20 × 10⁹/L. Mean platelet volume (MPV) was 10.6 ± 1.4 fL. No dysplastic changes were noted in bone marrow aspirate. Initial first-line therapy was sufficient for 45% of patients, second-line therapy was administered in 25%, splenectomy was performed in 20%, and 10% received all available treatments. Conclusions: The severe clinical form of pediatric chITP is accompanied by a low platelet count, the presence of autoimmune comorbidities, a positive family medical history, resistance to initial therapy, hypovitaminosis D, and rare megakaryocytes in the bone marrow.

28 February 2026 in Biomedicines
Verified
Journal Article
Open access
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DKDjordje Kralj
Djordje Kralj
MMMladen Maksic
Mladen Maksic
TITamara Knezevic Ivanovski
Tamara Knezevic Ivanovski
OGOlga Golubovic
Olga Golubovic
TVTijana Veljkovic
Tijana Veljkovic
SMSrdjan Markovic
Srdjan Markovic
Inflammatory bowel disease is a recognized risk factor for venous thromboembolism, whereas arterial thrombotic events remain underappreciated despite their substantial clinical consequences. We report a 45-year-old man without significant comorbidities who developed severe ulcerative colitis complicated by diffuse arterial thrombosis, including cerebral infarctions, an ascending aortic mural thrombus, iliac artery thrombosis, and multi-organ infarctions. After stabilization with supportive care and anticoagulation, remission-directed ulcerative colitis therapy and a vascular safety–oriented maintenance strategy were initiated, including vedolizumab and individualized secondary thrombosis prevention. To contextualize this presentation, we integrate current evidence on the epidemiology, clinical phenotypes, underlying mechanisms, and risk factors for arterial thrombosis in inflammatory bowel disease, highlight disease activity as a dominant trigger, and summarize therapy-specific vascular safety considerations across IBD treatment classes.

7 April 2026 in Diagnostics
Verified
Journal Article
Open access
PDF file
VMVladan Markovic
Vladan Markovic
SMSlobodanka Mitrovic
Slobodanka Mitrovic
TVTijana Veljkovic
Tijana Veljkovic
Irfan CorovicIrfan Corovic
Irfan Corovic
MSMarija Sekulic
Marija Sekulic
VGVesna Grbovic
Vesna Grbovic
Background: Fine-needle aspiration biopsy (FNAB) is the standard initial diagnostic procedure for thyroid nodules; however, a considerable proportion of results are non-diagnostic or indeterminate, often requiring repeat procedures and delaying management. Core needle biopsy (CNB) has been proposed as a second-line option. This study evaluated the frequency of non-conclusive FNAB and CNB results and assessed the diagnostic contribution of CNB in nodules with initially non-conclusive FNAB findings. Methods: A retrospective–prospective study was conducted between 2019 and 2025 at a tertiary referral center, including 434 thyroid nodules. Ultrasound risk stratification followed ACR TI-RADS criteria. FNAB was performed in 430 nodules, and CNB in 85 nodules, including 82 evaluated by both methods. Biopsy results were classified according to the Bethesda system as conclusive or non-conclusive. Paired comparisons were analyzed using the McNemar test, and associations with ultrasound risk were assessed. Results: FNAB produced non-conclusive results in 56.5% of cases, compared with 23.5% for CNB. In paired analysis, 53.7% of nodules with non-conclusive FNAB were reclassified as conclusive after CNB (p < 0.001). CNB significantly distinguished benign from malignant lesions, unlike FNAB. Hypoechogenicity, irregular margins, and punctate echogenic foci were independent predictors of malignancy. Minor complications were more frequent after CNB, while major complications were rare in both groups. Conclusions: CNB improves diagnostic yield when used as a second-line procedure in nodules with non-conclusive FNAB findings. Selective use in higher-risk nodules may reduce repeat procedures and facilitate more structured clinical management.