Katalin Bartyik

Late effects on renal glomerular and tubular function in childhood cancer survivors

Late nephrotoxicity among childhood cancer survivors is poorly documented.

Prevention and treatment of hyperuricemia with rasburicase in children with leukemia and non-Hodgkin's lymphoma

To prevent acute renal failure in children at risk for developing tumor lysis syndrome due to acute lymphoblastic leukemia or non-Hodgkin’s lymphoma treated according to international BFM protocols, we investigated recombinant urate oxidase (rasburicase) in the first Central European openlabeled, prospective, multicenter phase IV trial. Rasburicase was administered intravenously, at 0.2 mg/kg for 5 consecutive days to 36 patients. Blood levels of uric acid, creatinine, phosphorus, calcium, lactate dehydrogenase and complete blood count were measured daily during rasburicase treatment and on days 6, 7 and 12. Initial uric acid level decreased significantly by 4 hours (from 343 μmol/L to 58 μmol/L, p<0.001), except for one steroid-resistant patient who required hemodialysis on day 14 after having introduced combined cytostatic treatment. Comparing the data of a subgroup of 12 patients receiving rasburicase with that of a historic cohort of 14 patients treated with allopurinol indicated the superiority of rasburicase over allopurinol in prophylaxis and treatment of hyperuricemia in children with leukemia and lymphoma.

Hungarian experience with Langerhans Cell Histiocytosis in childhood

The Langerhans cell histiocytosis (LCH) in children is relatively rare and the long-term analysis of therapy results has not been done yet in Hungary. The aim of this study was to investigate the incidence, clinical features, prognostic risk factors, and treatment results of childrens LCH in Hungary in a 20-year period. Children less than 18 years of age with newly diagnosed LCH in Hungary were entered in this study. Clinical data of all children with LCH were reported to the National Childhood Cancer Registry in Hungary from 1981 to 2000. The clinical files were collected and abstracted for information regarding age at diagnosis, gender, disease characteristics, treatment, and outcome of treatment. Median follow-up duration of surviving patients is 10.98 years. Between January 1981 and December 2000, 111 children under 18 years of age were newly diagnosed with LCH in Hungary. The annual incidence of LCH in children younger than 18 years of age was 2.24/million children. The male–female ratio was 1.36:1; the mean age was 4 years 11 months. Thirty-eight children had localized disease and in 73 cases systemic dissemination was found already at the time of diagnosis. Twenty-two patients were treated only by local surgery, 7 by surgery with local irradiation, and 5 children got only local irradiation. In 2 cases remission was achieved with local steroid administration. Seventy-five patients received chemotherapy. In the 20 years of the study 14 children died, 9 due to the progression of the disease. Sixteen patients had relapse with a mean of 2.16 ± 1.29 years after the first diagnosis. Three patients with relapse got chemotherapy generally used in lymphoma and remission was achieved. The overall survival of all patients (n = 111) was 88.3 ± 3.1% at 5 years and 87.3 ± 3.2% at 10 and 20 years. Childhood LCH is a well-treatable disease and the survival rate is high. Even disseminated diseases have a quite good prognosis in childhood.

Childhood acute lymphoblastic leukaemia in relation to population mixing around the time of birth in South Hungary

In a retrospective epidemiological study of 481,984 live births in South Hungary, we investigated whether higher levels of population mixing around the time of birth is a risk factor for acute lymphoblastic leukemia (ALL) under age 5 years. Poisson regression was used to investigate the relationship between risk of ALL and the population‐mixing index based on the number of incomers in each county district for each year, standardized to have a range of 0–1. Among all children, the risk of ALL increased significantly with increasing population mixing around the time of birth (trend across the range of 0–1 RR = 2.1 95% CI: 1.02–4.44). This effect was more marked for boys (RR = 3.1 95% CI: 1.13–8.51), which supports a sex‐specific effect of exposures on risk of ALL. Pediatric Blood Cancer

Pulmonary capillary haemangiomatosis in children and adolescents: report of a new case and a review of the literature

Pulmonary capillary haemangiomatosis (PCH) in childhood is a rarity, characterised by the uncontrolled proliferation of pulmonary microvessels which may invade pulmonary, bronchial and vascular structures, resulting in diffuse alveolar haemorrhage, manifesting clinically in haemoptysis, dyspnoea and symptoms of pulmonary hypertension (PH). A 14-year-old boy with some particular features (pericardial effusion and thrombocytopenia) is presented and 14 paediatric/adolescent cases from the literature are surveyed. The diagnostic problems and difficulties are discussed, including the importance of imaging (high-resolution CT) and histopathological studies, with the aim of providing a clear-cut distinction of PCH from other conditions such as primary PH (PPH). The literature data can be regarded as ambiguous: both similarities and relatively sharp distinctions between PCH and PPH are to be found. New developments in the field of genetics are also discussed. The early coexistence of PCH and other (vascular) disorders and associations, involving focal or diffuse, disseminated forms is summarised briefly. Conclusion:The diagnosis of this progressive disorder may lead to effective therapy. Treatment possibilities include the rapidly evolving field of anti-angiogenic therapy, but at present lung transplantation is universally accepted as the final definitive treatment for pulmonary capillary haemangiomatosis.

Impact of single nucleotide polymorphisms of cytarabine metabolic genes on drug toxicity in childhood acute lymphoblastic leukemia

Cytarabine (cytosine arabinoside, ara‐C) is a chemotherapeutical agent used in the treatment of pediatric acute lymphoblastic leukemia (ALL). Adverse drug reactions, such as interpatient variability in sensitivity to ara‐C, are considerable and may cause difficulties during chemotherapy. Single nucleotide polymorphisms (SNPs) can play a significant role in modifying nucleoside‐drug pharmacokinetics and pharmacodynamics and thus the development of adverse effects. Our aim was to determine whether polymorphisms in genes encoding transporters and enzymes responsible for the metabolism of ara‐C are associated with toxicity and clinical outcome in a patient population with childhood ALL.

Sex chromosome changes after sex-mismatched allogeneic bone marrow transplantation can mislead the chimerism analysis

A 12‐year‐old male with pre‐B‐cell acute lymphoblastic leukemia with cryptic BCR/ABL rearrangement underwent sex‐mismatched allogeneic bone marrow transplantation (allo‐BMT). Contradictory results were provided by various chimerism analyses 3 months later. Y‐chromosome‐specific quantitative polymerase chain reaction and sex chromosome‐specific interphase fluorescence in situ hybridization (i‐FISH) showed complete donor chimerism. Analysis of autosomal short tandem repeats (A‐STR), BCR/ABL i‐FISH test, and X‐STR haplotype indicated relapse. Metaphase‐FISH and combined BCR/ABL and sex chromosome‐specific i‐FISH patterns revealed loss of the Y‐chromosome and duplication of the X‐chromosome in the host cells. Sex chromosome changes after allo‐BMT can cause significant difficulties in chimerism analysis. Pediatr Blood Cancer. 2010;55:1239–1242.

Sirolimus therapy in the treatment of pseudomyogenic hemangioendothelioma

Pseudomyogenic hemangioendothelioma (PMH) is a rare, mostly indolent vascular tumor. Extensive cases are treated with amputation as chemotherapy seems to be ineffective. Recently, promising results were published using mammalian target of rapamycin (mTOR) inhibitors in tumors of vascular origin. Here, we present a case of a child with advanced PMH relapsing after surgery and chemotherapy. Sirolimus achieved significant clinical improvement and stabilization of the lesions without any remarkable toxicity. This case contributes to the growing evidence regarding the efficacy of mTOR inhibitors, such as sirolimus, in multifocal PMH.

Detection of early precursors of t(12;21) positive pediatric acute lymphoblastic leukemia during follow-up†

DNA‐, RNA‐, and cell‐based methods provide different biologic information for determining the presence of minimal residual disease (MRD). We monitored the responses of patients with pediatric acute lymphoblastic leukemia (pALL) using DNA markers, TEL/AML1 expression, and scanning fluorescence microscopy (SFM). Using SFM, 36% of patients exhibited 1.5–3.1 log and 2.9–4.2 log higher MRD levels compared with those based on DNA and RNA markers, respectively. CD10+ ancestor cells with germline antigen receptors, but silent TEL/AML1 expression, may reside in the lymphoid stem cell compartment of treated t(12;21)‐positive patients and might act as a potential source of cells for late relapses. Pediatr Blood Cancer 2010; 54:158–160.

Korszakváltás a gyermekkori szerzett csontvelő-elégtelenséggel járó kórképek kezelésében Magyarországon

INTRODUCTION Acquired bone marrow failures are rare but fatal diseases in childhood. Since 2013, Hungary has been participating as a full member in the work of the European Working Group on uniform diagnostics and therapy in patients with acquired bone marrow failure syndromes. Hypocellular refractory cytopenia of childhood has been emphasized as a frequent entity, transplanted by reduced intensity conditioning with excellent outcomes. AIM To analyse and compare the results of treatment before and after our joining. METHOD A total of 55 patients have been treated in the 8 centres of the Hungarian Pediatric Oncology Network during 5 years between 2013 and 2017 (severe aplastic anemia: 9, myelodysplastic syndrome: 41, juvenile myelomonocytic leukemia: 5 patients). Allogeneic hematopoietic stem cell transplantation was performed in severe aplastic anemia in 7 cases, while antithymocyte globulin was administered in one case and one patient died before diagnosis. In patients with myelodysplastic syndromes, watch and wait strategy was applied in 4, while transplantation in 37 cases. Reduced intensity conditioning was used in 54 percent of these cases. Transplantation was the treatment of choice in all 5 patients with juvenile myelomonocytic leukemia. RESULTS In the whole patient cohort, the time from diagnosis to treatment was median 92 (3-393) days, while in severe aplastic anemia median 28 (3-327) days only. Grade II-IV acute graft versus host disease occurred in 22.6%, grade III-IV in 6.8% and chronic in 11.2%. All the patients treated with severe aplastic anemia are alive and in complete remission (100%). The overall estimated survival rate is 85.1% in myelodysplastic syndrome, while 75% in juvenile myelomonocytic leukemia. The median follow-up was 30.4 (1.1-62.5) months. There was a remarkable increase in overall survival comparing the data before (1992-2012) and after (2013) joining the international group, 70% vs. 100% (p = 0.133) in severe aplastic anemia and 31.3% vs. 85.1% (p = 0.000026) in myelodysplastic syndrome. CONCLUSION Due to a change in the paradigm of the conditioning regimen in hypocellular refractory cytopenia of childhood, the overall survival rate has significantly increased. Orv Hetil. 2018; 159(42): 1710-1719.