Browsing by Author "Krstovski, Nada (24724852600)"

Acute lymphoblastic leukemia (ALL) is the most common cancer in children, whereas it is less common in adults. Identification of cytogenetic aberrations and a small number of molecular abnormalities are still the most important risk and therapy stratification methods in clinical practice today. Next generation sequencing (NGS) technology provides a large amount of data contributing to elucidation of mutational landscape of childhood (cALL) and adult ALL (aALL). We analyzed DNA samples from 34 cALL and aALL patients, using NGS targeted sequencing TruSeq Amplicon - Cancer Panel (TSACP) which targets mutational hotspots in 48 cancer related genes. We identified a total of 330 variants in the coding regions, out of which only 95 were potentially protein-changing. Observed in individual patients, detected mutations predominantly disrupted Ras/RTK pathway (STK11, KIT, MET, NRAS, KRAS, PTEN). Additionally, we identified 5 patients with the same mutation in HNF1A gene, disrupting both Wnt and Notch signaling pathway. In two patients we detected variants in NOTCH1 gene. HNF1A and NOTCH1 variants were mutually exclusive, while genes involved in Ras/RTK pathway exhibit a tendency of mutation accumulation. Our results showed that ALL contains low number of mutations, without significant differences between cALL and aALL (median per patient 2 and 3, respectively). Detected mutations affect few key signaling pathways, primarily Ras/RTK cascade. This study contributes to knowledge of ALL mutational landscape, leading to better understanding of molecular basis of this disease. © 2019 Dragana Janic, Jelena Peric, Teodora Karan-Djurasevic, Tatjana Kostic, Irena Marjanovic, Bojana Stanic, Nadja Pejanovic, Lidija Dokmanovic, Jelena Lazic, Nada Krstovski, Marijana Virijevic, Dragica Tomin, Ana Vidovic, Nada Suvajdzic Vukovic, Sonja Pavlovic, Natasa Tosic, published by Sciendo.

Acute lymphoblastic leukemia (ALL) is the most common cancer in children, whereas it is less common in adults. Identification of cytogenetic aberrations and a small number of molecular abnormalities are still the most important risk and therapy stratification methods in clinical practice today. Next generation sequencing (NGS) technology provides a large amount of data contributing to elucidation of mutational landscape of childhood (cALL) and adult ALL (aALL). We analyzed DNA samples from 34 cALL and aALL patients, using NGS targeted sequencing TruSeq Amplicon - Cancer Panel (TSACP) which targets mutational hotspots in 48 cancer related genes. We identified a total of 330 variants in the coding regions, out of which only 95 were potentially protein-changing. Observed in individual patients, detected mutations predominantly disrupted Ras/RTK pathway (STK11, KIT, MET, NRAS, KRAS, PTEN). Additionally, we identified 5 patients with the same mutation in HNF1A gene, disrupting both Wnt and Notch signaling pathway. In two patients we detected variants in NOTCH1 gene. HNF1A and NOTCH1 variants were mutually exclusive, while genes involved in Ras/RTK pathway exhibit a tendency of mutation accumulation. Our results showed that ALL contains low number of mutations, without significant differences between cALL and aALL (median per patient 2 and 3, respectively). Detected mutations affect few key signaling pathways, primarily Ras/RTK cascade. This study contributes to knowledge of ALL mutational landscape, leading to better understanding of molecular basis of this disease. © 2019 Dragana Janic, Jelena Peric, Teodora Karan-Djurasevic, Tatjana Kostic, Irena Marjanovic, Bojana Stanic, Nadja Pejanovic, Lidija Dokmanovic, Jelena Lazic, Nada Krstovski, Marijana Virijevic, Dragica Tomin, Ana Vidovic, Nada Suvajdzic Vukovic, Sonja Pavlovic, Natasa Tosic, published by Sciendo.

Background: Surgical resection remains an important treatment of choice for a large number of liver tumors in children. Sometimes, if a tumor infiltrates a large part of the liver, after resection, the future liver remnant (FLR) is not enough for normal liver function. The size of the FLR is one of the determining factors for resectability as postoperative liver failure (PLF) is the most severe complication after partial hepatectomy. A new strategy for treating marginally resectable liver tumors in adult patients which were initially considered as unresectable was formally reported in 2011. This operative technique is a hepatectomy consisting of two stages with initial portal vein ligation and in situ splitting of the liver parenchyma. In 2012, the acronym “ALPPS” (associating liver partition and portal vein ligation for staged hepatectomy) was proposed for this novel technique. However, there is a small number of ALPPS procedures performed in pediatric patients published in the literature. Objectives: The aim of this paper is to present the first case of a pediatric patient with a marginally resectable rhabdoid tumor of the liver which was initially considered unresectable and who was treated with two-stage hepatectomy. We report a case of a 4-month-old girl with a large rhabdoid tumor of the liver who underwent this procedure. Conclusions: ALPPS can be a valuable technique to achieve complete resection of pediatric liver tumors although indications for ALPPS in children still need further research mainly focused on validation of the minimally needed FLR in children undergoing extended liver resections. To our knowledge, this is the youngest patient on whom ALPPS was performed, and the only one with a rhabdoid tumor. © 2025 by the authors.

Background: Surgical resection remains an important treatment of choice for a large number of liver tumors in children. Sometimes, if a tumor infiltrates a large part of the liver, after resection, the future liver remnant (FLR) is not enough for normal liver function. The size of the FLR is one of the determining factors for resectability as postoperative liver failure (PLF) is the most severe complication after partial hepatectomy. A new strategy for treating marginally resectable liver tumors in adult patients which were initially considered as unresectable was formally reported in 2011. This operative technique is a hepatectomy consisting of two stages with initial portal vein ligation and in situ splitting of the liver parenchyma. In 2012, the acronym “ALPPS” (associating liver partition and portal vein ligation for staged hepatectomy) was proposed for this novel technique. However, there is a small number of ALPPS procedures performed in pediatric patients published in the literature. Objectives: The aim of this paper is to present the first case of a pediatric patient with a marginally resectable rhabdoid tumor of the liver which was initially considered unresectable and who was treated with two-stage hepatectomy. We report a case of a 4-month-old girl with a large rhabdoid tumor of the liver who underwent this procedure. Conclusions: ALPPS can be a valuable technique to achieve complete resection of pediatric liver tumors although indications for ALPPS in children still need further research mainly focused on validation of the minimally needed FLR in children undergoing extended liver resections. To our knowledge, this is the youngest patient on whom ALPPS was performed, and the only one with a rhabdoid tumor. © 2025 by the authors.

Colorectal carcinoma is an extremely rare tumor in childhood. Therefore, the role of adjuvant chemotherapy has not been adequately evaluated in children leading to limited data on safety profile and treatment response after application of novel drugs and novel targeted agents. In this report, we describe a case of colon adenocarcinoma in a 13-year-old girl treated with standard adult treatment as well as novel targeted therapy. This case report illustrates initial good disease control with FOLFOX therapy. On the other hand, targeted therapy revealed no improvement in disease control and good safety profile without significant adverse effects. © 2012 Informa Healthcare USA, Inc.

Hodgkin Lymphoma is a complex malignancy with unique features, primarily affecting children and young adults. The disease’s sensitivity to radiation therapy and the young age of onset underscore the importance of optimizing treatment strategies to minimize both acute and long-term toxicities associated with radiotherapy. In light of these considerations, our study aimed to evaluate whether [18 F]FDG-PET/CT assessment at interim and end-of-treatment timings, in comparison to conventional CT scans, led to a decrease or increase in unnecessary patient exposure to radiotherapy. The study involved 61 pediatric patients diagnosed and treated for Hodgkin lymphoma at our institution between 2009 and 2022. Patients were categorized into two groups based on treatment protocols: Group 1 received conventional CT imaging protocols, while Group 2 received [18 F]FDG-PET/CT-based protocols. The results demonstrated that [18 F]FDG-PET/CT-based protocols led to a reduction in the frequency of radiotherapy compared to conventional CT imaging (32% vs. 52%). This statistically significant difference highlights the potential benefits of [18 F]FDG-PET/CT in guiding treatment decisions and reducing unnecessary radiation exposure. Our research re-emphasize the potential of [18 F]FDG-PET/CT as a valuable tool in the management of pediatric patients with Hodgkin lymphoma in terms of more precise diagnosis and reduction of unnecessary treatment and toxicities. © Indian Society of Hematology and Blood Transfusion 2024.

Background/Aim. The cause of eosinophilia often remains unelucidated. The aim of the study was to analyze causes and treatment approaches in children with eosinophilia in pediatric tertiary care hospital. Methods. The medical records of children investigated for eosinophilia (based on the International Classification of Diseases code D72.1) were retrospectively reviewed in the University Children’s Hospital, Belgrade, Serbia, from December 2011 to December 2022. A total of 105 children (62 boys; male:female ratio was 1:4) aged one month to 16.5 years (median 7.7 years) were diagnosed with eosinophilia. After excluding 15 of them due to incorrectly assigned diagnosis based on relative eosinophil number only, the remaining 90 children were grouped according to the severity of eosinophilia (mild, moderate or severe). Results. Serological analysis confirmed toxocariasis in six (6.7%) patients, while two (2.2%) had a confirmed nematode infestation (Ascaris lumbricoides and Enterobius vermicularis, respectively). Thirty-two (35.6%) children with eosinophilia and three with no true eosinophilia were diagnosed with helminthiasis ex juvantibus. Eosinophilia was ultimately explained by allergic/atopic conditions [19 (21.1%)], drug reactions [four (4.4%)], bacterial infections [nine (8.9%)], hematological problems [five (5.5%)], Apstrakt Uvod/Cilj. Uzrok eozinofilije često ostaje nerasvetlјen. Cilj rada bio je da se analiziraju uzrok i terapijski pristup kod dece sa eozinofilijom u pedijatrijskoj bolnici tercijarnog stepena zbrinjavanja. Metode. Retrospektivno je analizirana medicinska dokumentacija dece koja su ispitivana zbog eozinofilije (naznačene šifrom D72.1 na osnovu Međunarodne klasifikacije bolesti) u Univerzitetskoj dečjoj klinici u Beogradu, Srbija, u periodu od decembra 2011. do decembra 2022. Dijagnozu eozinofilije imalo je ukupno 105 dece (62 dečaka; odnos autoimmune disorders [three (3.3%)], unrelated congenital disorders (one), or as an isolated finding [seven (7.8%)]. In addition, one of the children without an increased absolute eosinophil number was diagnosed with eosinophilic esophagitis. A total of 56 (53.3%) children received anthelminthic treatment: 9 (90.0%) with severe eosinophilia, 19 (51.4%) with moderate, 23 (53.5%) with mild, and 5 (33.3%) children with no true eosinophilia. Most (42) of the children were given mebendazole only, while the remaining 14 (eight with severe, three with moderate, and three with mild) were also initially treated with mebendazole but subsequently shifted to albendazole due to the persistence of eosinophilia. In all treated children, eosinophilia and other relevant findings (if any) subsided in a matter of a few days to a few weeks after initializing treatment. Conclusion. Our results support the recommendation that unexplained eosinophilia of all levels of severity requires a standardized diagnostic approach. The results also provide some support for a potential rational basis for ex juvantibus administration of anthelminthic drugs in a fraction of children with eosinophilia without an obvious etiological explanation. © 2024 Inst. Sci. inf., Univ. Defence in Belgrade. All rights reserved.

Introduction Hemophagocytic lymphohistiocytosis (HLH) is a severe hyperinflammatory condition characterized by fever, cytopenias, hepatosplenomegaly and hemophagocytosis. HLH may be primary or secondary to infection, autoimmune disease or malignancy. Hypertriglyceridemia is a common abnormality in HLH and one of the HLH-2004 diagnostic criteria. Case Outline We present an infant with severe hypotonia and hypoproteinemic edema who also had extreme hypertriglyceridemia (21 mmol/l) and was diagnosed with HLH based on six of eight HLH- 2004 criteria (fever, hepatosplenomegaly, bicytopenia, hypertriglyceridemia with hypofibrinogenemia, sIL-2R > 2400 IU/ml, hemophagocytosis). The presence of IgM antibodies to Epstein–Barr virus and cytomegalovirus indicated a probable infectious trigger. The child was cured by the HLH-2004 protocol for secondary HLH (consisting of dexamethasone and cyclosporine). He was also found to have low serum hydroxycobalamin levels, promptly corrected upon hydroxycobalamin administration. Conclusion The presented case history underlines the need to ascertain the presence or absence of each of the eight HLH-2004 criteria in any patient suspected to suffer from HLH. © 2015, Serbia Medical Society. All rights reserved.

Langerhans cell histiocytosis (LCH) is characterized by the proliferation of clonal dendritic cells, while hemophagocytic lymphohistiocytosis (HLH) is an extreme inflammatory process sustained by the uncontrolled activation of macrophages. HLH can be primary or secondary, the latter arising in infectious, autoimmune or neoplastic disorders. We hereby present a young girl who developed secondary HLH while being treated for relapsed multisystem LCH under the LCH III Protocol. She fulfilled 5 of 8 HLH-2004 criteria (fever, splenomegaly, pancytopenia, ferritin level >500 μ/l and sIL-2R >2400 IU/ml) and was successfully treated by the HLH-2004 Protocol for secondary HLH. She remains in good health, apart from insipid diabetes she developed as a complication of LCH. Considering that the occurrence of HLH in LCH patients has been reported before, the case history presented here yields additional support for the hypothesis that the pathogenesis of the two histiocytoses –LCH and HLH – may indeed overlap to a considerable extent. © 2014, Turkish Journal of Pediatrics. All rights reserved.

Mutations in the fms-like tyrosine kinase 3 (FLT3) gene (internal tandem duplication (ITD) and point mutation in the tyrosine kinase domain, FLT3/D835) as well as the nucleophosmin (NPM1) gene are the most common abnormalities in adult acute myeloid leukemia (AML). Their significance in pediatric AML is still unclear. In this study we evaluated the frequency of FLT3 and NPM1 mutations in childhood AML. We also examined clinical features and outcome of these patients. FLT3 and NPM1 mutations were analysed in 42 and 37 childhood AML patients, respectively, using polymerase chain reaction (PCR) and direct sequencing. FLT3 mutations were detected in 4/42 patients (9.5%). The frequencies of FLT3/ITD and FLT3/D835 were the same, 2/42 (4.7%). NMP1 mutations were found in 1/37 patients (2.7%). FLT3 gene mutations were correlated with induction failure. Here we report the results of the study of FLT3 and NPM1 gene mutations in childhood AML patients in Serbia. Low frequencies of these molecular markers point out that these abnormalities are rare in this cohort of patients. Comparative study of data on NPM1 mutations in childhood AML revealed that various NPM1 gene mutation types are associated with childhood AML. Our findings as well as previously reported data, contributes to a hypothesis of different biology and etiology of adult and childhood AML. More extensive studies of NPM1 and FLT3 mutations in childhood AML are needed to determine their biological and clinical importance. © 2009 Humana Press Inc.

Mutations in the fms-like tyrosine kinase 3 (FLT3) gene (internal tandem duplication (ITD) and point mutation in the tyrosine kinase domain, FLT3/D835) as well as the nucleophosmin (NPM1) gene are the most common abnormalities in adult acute myeloid leukemia (AML). Their significance in pediatric AML is still unclear. In this study we evaluated the frequency of FLT3 and NPM1 mutations in childhood AML. We also examined clinical features and outcome of these patients. FLT3 and NPM1 mutations were analysed in 42 and 37 childhood AML patients, respectively, using polymerase chain reaction (PCR) and direct sequencing. FLT3 mutations were detected in 4/42 patients (9.5%). The frequencies of FLT3/ITD and FLT3/D835 were the same, 2/42 (4.7%). NMP1 mutations were found in 1/37 patients (2.7%). FLT3 gene mutations were correlated with induction failure. Here we report the results of the study of FLT3 and NPM1 gene mutations in childhood AML patients in Serbia. Low frequencies of these molecular markers point out that these abnormalities are rare in this cohort of patients. Comparative study of data on NPM1 mutations in childhood AML revealed that various NPM1 gene mutation types are associated with childhood AML. Our findings as well as previously reported data, contributes to a hypothesis of different biology and etiology of adult and childhood AML. More extensive studies of NPM1 and FLT3 mutations in childhood AML are needed to determine their biological and clinical importance. © 2009 Humana Press Inc.

Purpose: To analyze influence of variants in TYMS, MTHFR, SLC19A1 and DHFR genes on 6-mercaptopurine (MP) induced toxicity during maintenance phase of treatment for childhood acute lymphocytic leukemia (ALL). Methods: One-hundred twenty-seven children with ALL that received maintenance therapy were involved in this study. All patients were treated according to Berlin-Frankfurt-Muenster (BFM) based protocols. Myelotoxicity and hepatotoxicity were evaluated using surrogate markers (median 6-MP dose, number of leukopenic episodes and levels of bilirubin and transaminases on each visit). Results: Higher number of leukopenic episodes, as a surrogate marker of 6-MP myelotoxicity, was found in carriers of TYMS 3R3R and 3R4R genotypes (p=0.067) as well as in TYMS 3R6bp+ (28bp VNTR, 6bp indel) haplotype carriers (p=0.015). Carriers of DHFR CATAG (-680,-675,-556,-464,-317) haplotype were also found to have higher number of leukopenic episodes (p=0.070). SLC19A1 c.80A allele (p=0.079) and TYMS 2R6bp+ (5'UTR VNTR, 6bp indel) haplotype carriers (p=0.078) had fewer leukopenic episodes. No difference in genotype frequencies between the control group of volunteered blood donors and childhood ALL patients was found. Conclusions: Variants in TYMS, SLC19A1 and DHFR genes are potential biomarkers of myelotoxicity and could be used for 6-MP therapy individualization in maintenance phase of childhood ALL treatment, alongside with well-established TPMT variants. © 2019 Zerbinis Publications. All rights reserved.

Purpose: To analyze influence of variants in TYMS, MTHFR, SLC19A1 and DHFR genes on 6-mercaptopurine (MP) induced toxicity during maintenance phase of treatment for childhood acute lymphocytic leukemia (ALL). Methods: One-hundred twenty-seven children with ALL that received maintenance therapy were involved in this study. All patients were treated according to Berlin-Frankfurt-Muenster (BFM) based protocols. Myelotoxicity and hepatotoxicity were evaluated using surrogate markers (median 6-MP dose, number of leukopenic episodes and levels of bilirubin and transaminases on each visit). Results: Higher number of leukopenic episodes, as a surrogate marker of 6-MP myelotoxicity, was found in carriers of TYMS 3R3R and 3R4R genotypes (p=0.067) as well as in TYMS 3R6bp+ (28bp VNTR, 6bp indel) haplotype carriers (p=0.015). Carriers of DHFR CATAG (-680,-675,-556,-464,-317) haplotype were also found to have higher number of leukopenic episodes (p=0.070). SLC19A1 c.80A allele (p=0.079) and TYMS 2R6bp+ (5'UTR VNTR, 6bp indel) haplotype carriers (p=0.078) had fewer leukopenic episodes. No difference in genotype frequencies between the control group of volunteered blood donors and childhood ALL patients was found. Conclusions: Variants in TYMS, SLC19A1 and DHFR genes are potential biomarkers of myelotoxicity and could be used for 6-MP therapy individualization in maintenance phase of childhood ALL treatment, alongside with well-established TPMT variants. © 2019 Zerbinis Publications. All rights reserved.

Introduction Intensive treatment protocols used for non-Hodgkin lymphoma in children lead to eventfree survival rates ranging from 80% to 90%. However, the results are less successful in developing countries. Lymphoblastic lymphoma (LBL) is the second most frequent type of lymphoma in children, contributing with about one third to all non-Hodgkin lymphoma in childhood. Objective The aim of the study was to evaluate the results of LBL treatment in University Children’s Hospital (UCH), Belgrade. Methods A retrospective analysis of patient records at UCH from 1997 to 2015 was carried out in patients aged 0–18 years, in whom the diagnosis of LBL had been established. Twenty-two children were included in the analysis. Results Mean age at diagnosis was 10 years, with preponderance of male patients. All patients were treated according to Berlin-Frankfurt-Munster-based chemotherapy protocols. With median follow-up of 91.5 months, five-year probability of event-free survival was 79.5% for all patients, while overall survival was 81.8%. Conclusion Our results, although slightly inferior to those of leading international groups, reflect a good treatment outcome in our patients. © 2016, Serbia Medical Society. All rights reserved.

Introduction/Objective Next generation sequencing (NGS) technology has enabled genomic profiling of each patient. Growing knowledge in pharmacogenomics makes it possible to use NGS data for discovery of novel potential genetic markers for targeted therapy of many diseases, especially cancers. The aim of this study was to use targeted NGS to make a genetic profile of childhood acute lymphoblastic leukemia (cALL) in order to evaluate potential molecular targets for targeted therapy. Methods We analyzed DNA samples from 17 cALL patients using NGS targeted sequencing. Advanced bioinformatic analysis was used to identify novel mutations in analyzed genes and to predict their effect and pharmacogenomic potential. Results We identified nine variants that have not been previously reported in relevant databases, including two stop-gain variants, ABL1 p.Q252* and AKT1 p.W22*, one frameshift, STK11 p.G257fs*28, and six missense variants. We created three-dimensional models of four proteins harboring novel missense variants. We analyzed pharmacogenomic potential of each variant and found that two of them, STK11 c.1023G>T/ p.L341F and ERBB2 c.2341C>T/ p.R781W, are suitable candidates for targeted therapy. Conclusion Most new variants detected in this study were found in the genes associated with Ras signaling pathway, which is frequently mutated in cALL patients. Pharmacogenomic profiling of each cALL will be indispensable for novel therapy approaches. Detection and initial analysis of novel variants, presented in this study, will become a standard procedure for the design and development of individualized therapies for children with ALL, leading to improved patient outcomes. © 2018, Serbia Medical Society. All rights reserved.

Immune thrombocytopenic purpura (ITP) is an acquired immune-mediated bleeding disorder characterized by isolated low platelet (PLT) counts. Immune thrombocytopenic purpura pathogenesis involves multiple immune mechanisms causing PLT destruction and inadequate production. Owing to impaired immune homeostasis, ITP patients can develop other than anti-PLT autoantibodies even in the absence of clinical signs of autoimmune disease, such as anti-thyroglobulin (TG) and anti-thyroperoxidase (TPO) antibodies. Our objective is to determine the prevalence of antithyroid antibodies (ATAs) in the population of pediatric ITP patients, and the differences in ATA positivity prevalence in newly diagnosed/persistent ITP, and chronic ITP patient subgroups, as well as to establish the impact of ATA positivity on the treatment outcomes. A cross-sectional observational study was conducted involving 75 pediatric patients diagnosed with ITP and 60 healthy controls, carried out over a period of 11 years. The prevalence of ATA was significantly higher in ITP patients compared with controls (28% vs 5%, P <.05). Initial PLT count was significantly lower in ATA-positive patients, but the treatment response did not differ between ATA-positive and ATA-negative patients. To conclude, our study confirmed that ITP patients have a higher prevalence of ATA compared with the healthy pediatric population; however, no association was found between ATA positivity and disease duration or treatment outcomes. Our findings suggest that ATA screening may not be prognostic for ITP in pediatric population, but further research with larger cohorts may be beneficial to elucidate the role of ATA in ITP pathogenesis and management. © The Author(s) 2024.

Use of current intensive chemotherapy protocols in pediatric non-Hodgkin lymphoma (NHL) in high-income countries resulted in event-free survival (EFS) rates ranging from 80 to 90%. The results are inferior in less privileged countries with limited resources for medical care. There are no reports about comprehensive data analysis in pediatric NHL in Serbia. A retrospective study was carried out at University Children's Hospital, Belgrade, in children aged less than 18 years diagnosed with non-Hodgkin lymphoma from 1997 to 2011. Fifty-seven children were eligible for analysis. Fourteen were diagnosed with lymphoblastic lymphoma, 38 with mature B-cell NHL (B-NHL), and 5 with anaplastic large-cell lymphoma. Mean age at diagnosis was 9.2 years, with male to female ratio 2.35:1. Children were treated according to Berlin-Frankfurt-Mnster (BFM) protocols. With median follow-up of 59.3 months, 5-year probability of EFS was 84.1% for all patients, whereas overall survival was 93%. These results with BFM protocol administration, although inferior to leading international groups, reflect good treatment outcome in our patients. To the best of the authors' knowledge, this article presents the first results regarding treatment and survival of childhood NHL in Serbia. © 2012 Informa Healthcare USA, Inc.

Methotrexate (MTX) is one of the staples of pediatric acute lymphoblastic leukemia (ALL) treatment. MTX targets the folate metabolic pathway (FMP). Abnormal function of the enzymes in FMP, due to genetic aberrations, leads to adverse drug reactions. The aim of this study was to investigate variants in pharmacogenes involved in FMP and their association with MTX pharmacokinetics (MTX elimination profile) and toxicity in the consolidation therapy phase of pediatric ALL patients. Eleven variants in the thymidylate synthetase (TYMS), methylenetetrahydrofolate reductase (MTHFR), dihydrofolate reductase (DHFR), SLC19A1 and SLCO1B genes were analyzed in 148 patients, using PCR-and sequencing-based methodology. For the Serbian and European control groups, data on allele frequency distribution were extracted from in-house and public databases. Our results show that the A allele of SLC19A1 c.80 variant contributes to slow MTX elimination. Additionally, the AA genotype of the same variant is a predictor of MTX-related hepatotoxicity. Patients homozygous for TYMS 6bp deletion were more likely to experience gastrointestinal toxicity. No allele frequency dissimilarity was found for the analyzed variants between Serbian and European populations. Statistical modelling did not show a joint effect of analyzed variants. Our results indicate that SLC19A1 c.80 variant and TYMS 6bp deletion are the most promising pharmacogenomic markers of MTX response in pediatric ALL patients. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.

Methotrexate (MTX) is one of the staples of pediatric acute lymphoblastic leukemia (ALL) treatment. MTX targets the folate metabolic pathway (FMP). Abnormal function of the enzymes in FMP, due to genetic aberrations, leads to adverse drug reactions. The aim of this study was to investigate variants in pharmacogenes involved in FMP and their association with MTX pharmacokinetics (MTX elimination profile) and toxicity in the consolidation therapy phase of pediatric ALL patients. Eleven variants in the thymidylate synthetase (TYMS), methylenetetrahydrofolate reductase (MTHFR), dihydrofolate reductase (DHFR), SLC19A1 and SLCO1B genes were analyzed in 148 patients, using PCR-and sequencing-based methodology. For the Serbian and European control groups, data on allele frequency distribution were extracted from in-house and public databases. Our results show that the A allele of SLC19A1 c.80 variant contributes to slow MTX elimination. Additionally, the AA genotype of the same variant is a predictor of MTX-related hepatotoxicity. Patients homozygous for TYMS 6bp deletion were more likely to experience gastrointestinal toxicity. No allele frequency dissimilarity was found for the analyzed variants between Serbian and European populations. Statistical modelling did not show a joint effect of analyzed variants. Our results indicate that SLC19A1 c.80 variant and TYMS 6bp deletion are the most promising pharmacogenomic markers of MTX response in pediatric ALL patients. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.

Introduction/Objective Hemophagocytic lymphohistiocytosis (HLH) is a severe hyperinflammatory condition characterized by fever, splenomegaly, and cytopenias. Diagnosis of HLH requires at least five of the eight criteria set by the Histiocyte Society and poses a significant challenge to physicians. HLH-2004 criteria include measurement of plasma levels of soluble receptor for interleukin-2 (sIL-2R), an invaluable tool in the diagnosis of HLH, particularly because it can be measured swiftly and inexpensively. Methods We retrospectively analyzed medical records of 45 pediatric patients (28 boys and 17 girls, median age 8.1 years) who were investigated for suspected HLH in University Children’s Hospital in Belgrade, during the period from 2012 to 2022. Results Ten children were diagnosed with HLH, while 35 did not have HLH. All 10 HLH patients had secondary HLH: eight suffered from infection or inflammatory condition, one from an autoimmune disease, and one from malignancy. Level of sIL-2R was above the HLH-2004 cutoff value of 2400 IU/ml in 9/10 patients with HLH (sensitivity 90%) and 9/35 of patients who did not have HLH (specificity 74.2%). Conclusion Soluble IL-2 receptor measurement is valuable in children suspected to have HLH. Sensitivity and specificity of this analysis can be further improved by strict patient selection and a comprehensive diagnostic approach. © 2023, Serbia Medical Society. All rights reserved.