Molecular Genetics Diversity of Primary Hemophagocytic Lymphohistiocytosis among Polish Pediatric Patients.

Hemophagocytic lymphohistiocytosis (HLH) is a clinical syndrome of life-threatening inflammation caused by an excessive, prolonged and ineffective immune response. An increasing number of HLH cases is recognized in Poland, but the genetic causes of familial HLH (FHL) have not been reported. We investigated the molecular genetics and associated outcomes of pediatric patients who met HLH criteria. We studied 54 patients with HLH, 36 of whom received genetic studies. Twenty-five patients were subjected to direct sequencing of the PRF1, UNC13D, STX11, XIAP and SH2D1A genes. Additionally, 11 patients were subjected to targeted next-generation sequencing. In our study group, 17 patients (31%) were diagnosed with primary HLH, with bi-allelic FHL variants identified in 13 (36%) patients whereas hemizygous changes were identified in 4 patients with X-linked lymphoproliferative diseases. In addition, one patient was diagnosed with X-linked immunodeficiency with magnesium defect, Epstein-Barr virus infection and neoplasia due to a hemizygous MAGT1 variant; another newborn was diagnosed with auto-inflammatory syndrome caused by MVK variants. The majority (65%) of FHL patients carried UNC13D pathogenic variants, whereas PRF1 variants occurred in two patients. Novel variants in UNC13D, PRF1 and XIAP were detected. Epstein-Barr virus was the most common trigger noted in 23 (65%) of the patients with secondary HLH. In three patients with secondary HLH, heterozygous variants of FHL genes were found. Overall survival for the entire study group was 74% with a median of 3.6 years of follow-up. Our results highlight the diversity of molecular causes of primary HLH in Poland.

Prevalence, Epidemiology, Etiology, and Sensitivity of Invasive Bacterial Infections in Pediatric Patients Undergoing Oncological Treatment: A Multicenter Nationwide Study.

Background: Infectious complications (IC) caused by bacterial strains often impede anticancer therapy. The study aimed to retrospectively analyze bacterial IC that could help predict the risk and optimize the empirical treatment for bacterial infections in pediatric cancer patients. Patients and Methods: Over a 72-month period, all-in 5,599 children with cancer: 2,441 patients with hematological malignancy (HM including acute leukemias, Hodgkin and non-Hodgkin lymphomas [NHLs], and Langerhans cell histiocytosis) and 3,158 with solid tumors (STs including central nervous system tumors, neuroblastoma, Wilms' tumor, soft tissue sarcoma, germ cell tumors, Ewing sarcoma, osteosarcoma, hepatoblastoma, and others) were enrolled into the study. Episodes of bacterial infectious complications (EBICs) confirmed by microbiological findings were reported by each hospital and analyzed centrally. Results: At least 1 EBIC was diagnosed in 2,155 (36.8%) children (1,281 [59.4%] with HM and 874 [40.6%] with ST; p < 0.001). All-in 4,860 EBICs were diagnosed including 62.2% episodes in children with HM and 37.8% in children with ST (p < 0.001). Having analyzed the source of infections, blood stream infections predominated, apart from NHL patients in whom the most common type was gut infections. The profile of bacteria strains was different in HM and ST groups (p < 0.001). However, in both groups the most common Gram-negative pathogen was Enterobacteriaceae, with the rate being higher in the HM group. Among Gram-negative strains low susceptibility to ceftazidime, whereas among Enterococcus spp. low susceptibility to vancomycin was noticed. The rate of multidrug-resistant (MDR) pathogens was high, especially for Gram negatives (47.7% vs. 23.9%; p < 0.001). The survival after infections was comparable for HM and ST patients (p = 0.215). Conclusions: The risk of bacterial IC in HM patients was higher than in the ST group. The high rate of MDR strains was detected in pediatric cancer patients, especially in those with HM.

Results of two consecutive treatment protocols in Polish children with acute lymphoblastic leukemia.

The aim of the study was to retrospectively compare the effectiveness of the ALL IC-BFM 2002 and ALL IC-BFM 2009 protocols and the distribution of risk groups by the two protocols after minimal residual disease (MRD) measurement as well as its impact on survival. We reviewed the medical records of 3248 patients aged 1-18 years with newly diagnosed ALL who were treated in 14 hemato-oncological centers between 2002 and 2018 in Poland. The overall survival (OS) of 1872 children with ALL treated with the ALL IC 2002 protocol was 84% after 3 years, whereas the OS of 1376 children with ALL treated with the ALL IC 2009 protocol was 87% (P < 0.001). The corresponding event-free survival rates were 82% and 84% (P = 0.006). Our study shows that the ALL IC-BFM 2009 protocol improved the results of children with ALL compared to the ALL IC-BFM 2002 protocol in Poland. This analysis confirms that MRD marrow assessment on day 15 of treatment by FCM-MRD is an important predictive factor.

Clinical characteristics and outcome of pediatric patients diagnosed with Langerhans cell histiocytosis in pediatric hematology and oncology centers in Poland.

BACKGROUND: Langerhans cell histiocytosis (LCH) affects 1-2 in 1,000,000 people. The disease is not associated with increased risk of treatment failure (especially among older children), but appropriate procedures implemented in advance can eliminate complications which might appear and significantly worsen the patients' quality of life. Thus, we sought to evaluate the clinical features, management, and outcome of children with LCH treated in Polish pediatric hematology-oncology centers. MATERIALS AND METHODS: One hundred eighty two patients with LCH were treated according to the Histiocytic Society Guidelines between 2010 and 2017. The participating centers were requested to provide the following data: demographic, clinical, as well as local or systemic treatment data and patients' outcome. Overall survival (OS) and event free survival (EFS) were estimated by Kaplan-Meier methods and compared using the log-rank test. RESULTS: Sixty nine percent of children were classified as single system (SS). The patients with SS disease were significantly older as compared to the children with multisystem disease (MS), 6 vs. 2.3 years respectively (p 0.003). Bones were involved in 76% of patients. Systemic treatment was applied to 47% of children with SS disease and 98% with MS disease. Fourteen patients relapsed while two children died. OS and EFS in entire group were 0.99 and 0.91 respectively (with median follow-up 4.3 years). CONCLUSION: The treatment of LCH in Polish centers was effective, however, new approaches, including mutation analyses and good inter-center cooperation, are needed to identify patients who might require modification or intensification of treatment.

The Treatment of Opsoclonus-Myoclonus Syndrome Secondary to Neuroblastic Tumours-Single-Centre Experience and Literature Review.

Background and Objectives: The opsoclonus-myoclonus syndrome (OMS) is characterised by opsoclons, myoclons and impaired balance, often concomitant with sleep disorder and behavioural difficulties. The symptoms develop as a result of autoimmune response triggered by a neuroblastic tumour (NT). OMS can also develop secondarily to a viral infection or as an immune response triggered by an unknown agent. This leads to the activation of B- and T-cells, which produce and release autoantibodies or cytokines directly within the central nervous system (CNS), thus damaging the neurons within the cerebellum and the brain stem. The available OMS treatments aim at decreasing lymphocyte, cytokine and autoantibody production or accelerating the utilisation of the latter. Another treatment option for OMS involves using cytostatic agents, which damage T- and B-cells causing their depletion and impaired function, which reduces their ability to produce antibodies and cytokines. Materials and Methods: We present a single-centre experience in treating OMS secondary to NT in 7 children. Results: The combined treatment with cyclophosphamide plus dexamethasone resulted in a complete resolution of OMS symptoms in 4 children, and a significant improvement in the 3 children. Two of them periodically present hyperactivity, and one girl requires an additional support at school due to special educational needs (SEN). Conclusions: NT resection does not resolve OMS in children with OMS secondary to NT. The combined treatment with dexamethasone plus cyclophosphamide seems to be an effective treatment of OMS.

Infections in children with acute myeloid leukemia: increased mortality in relapsed/refractory patients.

The aim of this nationwide study was to describe the epidemiology and profile of bacterial infections (BI), invasive fungal disease (IFD) and viral infections (VI) in patients with de novo and relapsed/refractory (rel/ref) acute myeloid leukemia (AML). Within the studied group of 250 children with primary AML, at least one infectious complication (IC) was diagnosed in 76.0% (n = 190) children including 85.1% (n = 504) episodes of BI, 8.3% (n = 49) - IFD and 6.6% (n = 39) - VI. Among 61 patients with rel/ref AML, at least one IC was found in 67.2% (n = 41) of children including 78.8% (n = 78) of BI, 14.1% (n = 14) of IFD and 7.1% (n = 7) of VI. In all AML patients, within BI Gram-negative strains were predominant. Half of these strains were multi-drug resistant. Characteristics of IFD and VI were comparable for de novo and rel/ref AML. The infection-related mortality was significantly higher, while survival from infection was significantly lower in patients with rel/ref disease.

Quality of life in survivors of childhood brain tumour and the association of children's diseases on quality of their parents life.

OBJECTIVE: Evaluation of children's quality of life (QoL) after finished brain tumour treatment and the association of children's diseases on quality of their parents' life. METHODS: The study group was consisted of 46 children after brain tumour treatment (aged 4, 5, to 29 years old). The control group was composed of 104 students of primary, secondary, and high schools. One hundred fifty (104 + 46) parents were included in the study. Standardised QoL questionnaires (PEDsQL-4.0, WHOQOL-BREF) were used. Survivors' QoL was assessed from patients' and their parents' point of view, also the association of children's diseases on quality of their parents' life was estimated. RESULTS: QoL of children after brain tumour treatment was lower than in the control group according to the children (P < 0.001) and their parents (P < 0.001). The survivors worst rated their ability to social functioning (P < 0.0010) and physical functioning (P < 0.001) in comparison with self-assessment of healthy children. According to their parents, the functioning of children in all zones was worse than in the control group, mostly in social (P < 0.001) and physical sphere (P < 0.001), too. QoL of children with low-grade tumour was comparable with QoL of children with high-grade tumour). QoL of survivors' caregivers in study was higher than QoL of parents of control groups (P = 0.023). CONCLUSIONS: The quality of patients' life after brain tumour treatment is lower in comparison with healthy children. QoL of the parents of survivor is higher than the QoL of healthy children parents. The assessment of QoL of children after brain tumour treatment should be an inherent element of health monitoring.

NK Cells as Possible Prognostic Factor in Childhood Acute Lymphoblastic Leukemia.

Deficiency or impaired function natural killer (NK) cells might result in the development of serious infections and promote the development of malignancies. The aim of our study was to assess the prognostic role of NK cell percentage in bone marrow on the day of acute lymphoblastic leukemia (ALL) diagnosis. 84 children (49 males = 58%; median age 5 yrs) with ALL were enrolled. The NK cell percentage was assessed using flow cytometry with antibodies against the cluster of differentiation (CD): CD3, CD56, and CD16. We evaluated two groups: group I (NK+), patients with NK cells in the bone marrow (n = 74), and group II (NK-), patients without NK cells in the bone marrow (n = 10) (cut-off value of negative <1%). In the patients from group I, the prednisone good response on day 8 and the remission on day 15 of treatment were observed significantly more often (p = .01, p = .03). The children from group I had significantly better survival as compared to those from group II (p = .02) (HR 2.59; 95% CI: 1.38-4.85). The presence of NK cells in the bone marrow at diagnosis can be a prognostic factor in children with ALL. The presented results should be the basis for further research.

Surface expression of Cytokine Receptor-Like Factor 2 increases risk of relapse in pediatric acute lymphoblastic leukemia patients harboring IKZF1 deletions.

We prospectively examined whether surface expression of Cytokine Receptor-Like Factor 2 (CRLF2) on leukemic blasts is associated with survival and induction treatment response in pediatric B-cell precursor acute lymphoblastic leukemia (BCP-ALL) patients. Flow cytometric analysis of bone marrow-derived leukemia cells revealed that 7.51% (29/286) of 386 pediatric BCP-ALL patients were CRLF2-positive (CRLF2pos) at diagnosis. The median minimal residual disease (MRD) was lower in CRLF2pos than CRLF2-negative (CRLF2neg) patients on day 15 (MRD15) after induction therapy [0.01% (0.001-0.42%) vs. 0.45% (0.05-3.50%); p=0.001]. By contrast, the MRD15 was higher in Ikaros family Zinc Finger Protein 1 (IKZF1)-deleted BCP-ALL patients than in BCP-ALL patients without IKZF1 deletions [1.18% (0.06-12.0%) vs 0.33% (0.03-2.6%); p=0.003]. Subgroup analysis showed that MRD15 levels were lower in IKZF1Δ/CRLF2pos patients than in IKZF1Δ/CRLF2neg patients [0.1% (0.02-5.06%) vs. 2.9% (0.25-12%); p=0.005]. Furthermore, MRD15 levels were higher in IKZF1WT/CRLF2neg patients than in IKZF1WT/CRLF2pos patients [0.40% (0.04-2.7%) vs. 0.001% (0.001-0.01%)]. Despite the low MRD15 levels, IKZF1Δ/CRLF2pos patients showed poorer relapse-free survival (RFS) than other patient groups (p=0.003). These findings demonstrate that surface CRLF2 expression is associated with increased risk of relapse in pediatric BCP-ALL patients harboring IKZF1 deletions.

Blastic Plasmocytoid Dendritic Cell Neoplasm With Skin and Myeloid Location.

Blastic plasmocytoid dendritic cell neoplasm is one of the aggressive hematopoietic malignancy with predilection for the skin. It is a tumor derived from the plasmocytoid dendritic precursor cells. Skin is its most common location; however, it may also affect bone marrow, lymph nodes, or spleen. The condition is rarely diagnosed in children; so far only 36 cases have been reported. The diagnosis usually takes time and there are no uniform treatment guidelines. This paper presents a case of a 6-year-old boy with blastic plasmocytoid dendritic cell neoplasm (skin and myeloid location). He has been treated according to the acute lymphoblastic leukemia treatment protocol.

PRES in the course of hemato-oncological treatment in children.

INTRODUCTION: Posterior reversible leukoencephalopathy syndrome (PRES) is a clinical syndrome of varying aetiologies, characterised by acute neurological symptoms of brain dysfunction with MRI abnormalities in posterior cerebral white and grey matter. In most cases, symptoms resolve without neurological consequences. AIM: The aim of this paper is the analysis of predisposing factors, clinical outcomes and radiological features of PRES in eight children with hemato-oncological disease. MATERIAL AND METHODS: We analysed the medical records of eight hemato-oncological patients aged from 3.0 to 16.1 years. The mean of age at primary diagnosis was 8.5 years. RESULTS: All patients had both clinical and radiological PRES features. Seven out of eight underwent intensive chemotherapy regimens. Time elapsed from start of treatment to the occurrence of PRES ranged from 6 to 556 days. In one case, PRES occurred before chemotherapy and was the first symptom of cancer. Most (six of eight) patients had history of hypertension (> 95pc) and some (two of eight) occurred electrolyte imbalance-mainly hypomagnesaemia. Patients presented headache (seven of eight), disturbances of consciousness (six of eight), seizures (six of eight), visual changes (four of eight) and vomiting (three of eight). MRI demonstrated abnormalities in seven children: typical cerebral oedema in the white matter of the occipital to the parietal lobes. Most patient lesions in the MRI shrunk after 4 weeks, and clinical symptoms of PRES disappeared completely within a few hours to few days. CONCLUSION: PRES may complicate oncological treatment in children. Hypertension is the most important risk factor of PRES. PRES should be included in differential diagnosis in all patients with acute neurological symptoms.

[Difficulties of the therapy in a boy with coexisting type 1 diabetes mellitus and idiopathic thrombocytopenic purpura]. / Trudnosci terapeutyczne u pacjenta ze wspólistniejaca cukrzyca typu 1 oraz maloplytkowoscia immunologiczna.

Idiopathic thrombocytopenic purpura (ITP) is an acquired autoimmune disease, caused by antibodies against platelet glycoproteins, which provoke platelet destruction and inhibit platelet production in bone marrow. Type 1 Diabetes Mellitus (T1DM) is an acquired autoimmune disease in witch beta cells are destroyed by autoantibodies. Patient with T1DM since the age of 6, was treated by intensive functional insulin therapy by insulin pump. At the age of 14,5 he was also diagnosed with ITP. Due to the short effect of immunoglobulin therapy, glucocorticoids were introduced. After 3 months of glucocorticotherapy the platelet count was 46 G/l. Patient developed various adverse effects of glucocorticoids, among others stretch marks covering all surface of his abdomen, buttocks, arms and thighs and raise in the daily requirement of insulin by 200%. Adverse effects of glucocorticotherapy made impossible the therapy by insulin pump and imposed urgent revision of the ITP therapy. Side effects of the glucocorticotherapy can make impossible the treatment by insulin pump of T1DM in children.

Assessment of Angiogenesis in Children with Acute Lymphoblastic Leukemia Based on Serum Vascular Endothelial Growth Factor Assay.

INTRODUCTION: Vascular endothelial growth factor A (VEGFA) is a key proangiogenic cytokine. The role of angiogenesis in acute lymphoblastic leukemia (ALL) is still unclear. The purpose of the study was to assess angiogenesis in children with ALL based on serum VEGFA level determined at diagnosis and at remission with further participant subdivision into different risk groups. MATERIALS AND METHODS: Forty children, aged 3-12 years (mean age: 8 years) with newly diagnosed ALL, were enrolled in the study. The control group (Group C) was twenty healthy children. According to the risk assessment, they were classified into a standard-risk group, an intermediate-risk group (IRG), or a high-risk group (HRG). RESULTS: The median serum VEGFA levels at diagnosis were significantly higher in IRG and HRG as compared to Group C. The VEGFA levels at remission were significantly higher in all study groups, as compared to Group C. The differences in median values of serum VEGFA levels between the study groups both at diagnosis and at remission were not statistically significant. CONCLUSIONS: The angiogenesis in ALL seems to be intensified at diagnosis as a result of neoplasmatic bone marrow rebuilding and at remission as its intensive recovering.

Outcome of acute lymphoblastic leukemia in children with down syndrome-Polish pediatric leukemia and lymphoma study group report.

Children with Down syndrome (DS) have a 20-fold increased risk of developing leukemia compared with the general population. The aim of the study was to analyze the outcome of patients diagnosed with Down syndrome and acute lymphoblastic leukemia (ALL) in Poland between the years 2003 and 2010. A total of 1848 children were diagnosed with ALL (810 females and 1038 males). Of those, 41 (2.2%) had DS. The children were classified into three risk groups: a standard-risk group-14 patients, an intermediate-risk group-24, a high-risk group-3. All patients were treated according to ALLIC 2002 protocol. The median observation time of all patients was 6.1 years, and in patients with DS 5.3 years. Five-year overall survival (OS) was the same in all patients (86% vs 86%, long-rank test, p = .9). The relapse-free survival (RFS) was calculated as 73% in patients with DS and 81% in patients without DS during a median observation time (long-rank test, p = .3). No statistically significant differences were found in the incidence of nonrelapse mortality between those two groups of patients (p = .72). The study was based on children with ALL and Down syndrome who were treated with an identical therapy schedule as ALL patients without DS, according to risk group. This fact can increase the value of the presented results.

Serum levels of vascular endothelial growth factor and basic fibroblast growth factor in children with brain tumors.

BACKGROUND: Angiogenesis is the process of new vessel formation originating from the existing vascular network. It plays an important role in the growth and spread of malignancies, including brain tumors. The process of angiogenesis is characterized by increased expression of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF), and by the release of their soluble forms into circulation. OBJECTIVES: The aim of the study was to evaluate serum levels of VEGF and bFGF in children with malignant and benign brain tumors. MATERIAL AND METHODS: The study group (group N) included 106 children diagnosed with brain tumors. The children in group N were classified according to tumor pathology into 3 subgroups: N1 (n = 63): patients with malignant tumors, excluding anaplastic astrocytoma (AA) and glioblastoma multiforme (GBM); N2 (n = 25): patients with benign tumors; and N3 (n = 18): patients with high grade gliomas (AA and GBM). VEGF and bFGF were determined by ELISA in blood samples before the initiation of chemotherapy. VEGF and bFGF levels were compared within the subgroups in relation to tumor grading and the extent of surgery. RESULTS: The median VEGF in patients with brain tumors was significantly higher than in the control group. The median levels of VEGF and bFGF in subgroup N1 were significantly higher than in the control group. The differences in VEGF and bFGF concentrations between the subgroups in relation to the extent of tumor resection were not significant. CONCLUSIONS: Significantly higher plasma VEGF levels in children with brain neoplasms may reflect enhanced angiogenesis in the tumors.

Renal function in children treated for central nervous system malignancies.

AIM: The aim of the study was to evaluate renal function and to assess the usefulness of the following nephrotoxicity markers: cystatin C (CYS C), beta-2 microglobulin (B2MG) and neutrophil gelatinase-associated lipocalin (NGAL) in 38 (18 girls, 20 boys) children previously treated for central nervous system malignancy. MATERIAL: Median age at evaluation was 13.7 years (range 2.1-22 years). The mean follow-up time after the completion of chemotherapy was 3.2 years (range 0.16-6.5 years). RESULTS: Subclinical chronic kidney disease (estimated glomerular filtration rate: eGFR 90-60 ml/min/1.73 m(2)) was found in 22 patients (58 %), while renal insufficiency (eGFR 30-60 ml/min/1.73 m(2)) was found in six children (16 %). It has been demonstrated statistically significant negative correlation between the eGFR and cystatin C concentration (p < 0.0001) and eGFR and beta-2 microglobulin concentration (p < 0.02). Conversely, there was no correlation between eGFR and NGAL. Thirteen children (34 %) developed drug-induced tubulopathy: decreased tubular reabsorption of phosphate (TRP) and renal tubular threshold for phosphate (Tmp/GFR). CONCLUSION: Children treated for CNS tumours often develop drug-induced chronic renal disease, involving the glomeruli and/or renal tubules. Cystatin C and beta-2 microglobulin seemed to be good markers for chronic kidney damage in these patients, which is probably not true for NGAL.

Inflammatory Myofibroblastic Tumor of the Heart in the Infant: Review of the Literature.

Primary heart tumors are extremely rare, constituting approximately 0.02% of all malignancies. Inflammatory myofibroblastic tumor (IMT) constitutes <5% of primary heart tumors. Until now, IMT of the heart has been described in 21 infants below 1 year of age. Its etiology remains unknown. IMT usually develops within the right atrial and ventricular endocardium. The main clinical symptoms reported in the affected infants involved increasing respiratory failure, cyanosis, and heart murmurs. Histopathologically, IMT is characterized by the myofibroblast proliferation with inflammatory infiltrates composed of plasmocytes, lymphocytes, and histiocytes. Tumor resection is the treatment of choice in IMT. Such tumor location is associated with the high risk of perioperative failure. Steroid therapy and chemotherapy is reported in the literature as a nonsurgical treatment alternative. Here, we present a review of clinical symptoms, diagnostic and treatment options, based on published case reports of IMT in infants, including our 11-month-old patient with IMT located within the pericardium.

Expression of myeloid antigens on lymphoblast surface in childhood acute lymphoblastic leukemia at diagnosis and its effect on early response to treatment: a preliminary report.

Immunodiagnosis of acute lymphoblastic leukemia (ALL) is based on the assessment of surface antigens. There are also cases in which both lymphoid and myeloid antigens can be found on the surface of lymphoblasts. The purpose of our research was to assess the expression of myeloid and lymphoblastic antigens in children with ALL, and to determine the impact of surface antigens on early response to treatment. 58 children [33 girls (56.9 %), 25 boys (43.2 %)] with ALL were studied. Response to treatment was assessed on days 8, 15, and 33. Univariate logistic regression analysis of the effect of myeloid antigens (MyAg) on response to treatment on days 8 and 33 revealed expression of any MyAg on lymphoblast surface as a factor associated with poor response to treatment. The multivariate logistic regression analysis of treatment response on day 33, showed that the expression of CD13 antigen on lymphoblast surface is a key factor affecting delayed remission (p = 0.03; odds ratio 0.12; 95 % CI 0.01-0.81). The expression of MyAg in childhood ALL adversely affects early response to treatment. The expression of CD13 antigen on day 33 is a key factor affecting complete remission in ALL patients.