COVID-19 disease in children and adolescents following allogeneic hematopoietic stem cell transplantation: A report from the Turkish pediatric bone marrow transplantation study group.

BACKGROUND: Data on the risk factors and outcomes for pediatric patients with SARS-CoV-2 infection (COVID-19) following hematopoietic stem cell transplantation (HSCT) are limited. OBJECTIVES: The study aimed to analyze the clinical signs, risk factors, and outcomes for ICU admission and mortality in a large pediatric cohort who underwent allogeneic HSCT prior to COVID-19 infection. METHOD: In this nationwide study, we retrospectively reviewed the data of 184 pediatric HSCT recipients who had COVID-19 between March 2020 and August 2022. RESULTS: The median time from HSCT to COVID-19 infection was 209.0 days (IQR, 111.7-340.8; range, 0-3845 days). The most common clinical manifestation was fever (58.7%). While most patients (78.8%) had asymptomatic/mild disease, the disease severity was moderate in 9.2% and severe and critical in 4.4% and 7.6%, respectively. The overall mortality was 10.9% (n: 20). Deaths were attributable to COVID-19 in nine (4.9%) patients. Multivariate analysis revealed that lower respiratory tract disease (LRTD) (OR, 23.20, p: .001) and lymphopenia at diagnosis (OR, 5.21, p: .006) were risk factors for ICU admission and that HSCT from a mismatched donor (OR, 54.04, p: .028), multisystem inflammatory syndrome in children (MIS-C) (OR, 31.07, p: .003), and LRTD (OR, 10.11, p: .035) were associated with a higher risk for COVID-19-related mortality. CONCLUSION: While COVID-19 is mostly asymptomatic or mild in pediatric transplant recipients, it can cause ICU admission in those with LRTD or lymphopenia at diagnosis and may be more fatal in those who are transplanted from a mismatched donor and those who develop MIS-C or LRTD.

Central nervous system thrombosis in pediatric acute lymphoblastic leukemia in Turkey: A multicenter study.

BACKGROUND: In patients with acute lymphoblastic leukemia (ALL), the risk of thromboembolism increases due to hemostatic changes secondary to the primary disease and due to treatment-related factors. In this multicenter study, we aimed to research the frequency of central nervous system (CNS) thrombosis occurring during treatment, hereditary and acquired risk factors, clinical and laboratory features of patients with thrombosis, treatment approaches, and thrombosis-related mortality and morbidity rates in pediatric ALL patients. PROCEDURE: Pediatric patients who developed CNS thrombosis during ALL treatment from 2010 to 2021 were analyzed retrospectively in 25 different Pediatric Hematology Oncology centers in Türkiye. The demographic characteristics of the patients, symptoms associated with thrombosis, the stage of the leukemia treatment during thrombosis, the anticoagulant therapy applied for thrombosis, and the final status of the patients recorded through electronic medical records were determined. RESULTS: Data from 70 patients with CNS thrombosis during treatment, out of 3968 pediatric patients with ALL, were reviewed. The incidence of CNS thrombosis was 1.8% (venous: 1.5 %; arterial: 0.03%). Among patients with CNS thrombosis, 47 had the event in the first 2 months. Low molecular weight heparin (LMWH) was the most commonly used treatment with a median of 6 months (min-max: 3-28 months). No treatment-related complications occurred. Chronic thrombosis findings occurred in four patients (6%). In five (7%) patients who developed cerebral vein thrombosis, neurological sequelae (epilepsy and neurological deficit) remained. One patient died related to thrombosis, and the mortality rate was 1.4%. CONCLUSION: Cerebral venous thrombosis and, less frequently, cerebral arterial thrombosis may develop in patients with ALL. The incidence of CNS thrombosis is higher during induction therapy than during other courses of treatment. Therefore, patients receiving induction therapy should be monitored carefully for clinical findings suggestive of CNS thrombosis.

Zinc finger protein 384 (ZNF384) impact on childhood mixed phenotype acute leukemia and B-cell precursor acute lymphoblastic leukemia.

B-cell precursor acute lymphoblastic leukemia (BCP-ALL) is a heterogeneous malignancy and consists of several genetic abnormalities. Some of these abnormalities are used in clinics for risk calculation and treatment decisions. Patients with ZNF384 rearrangements had a distinct expression profile regardless of their diagnosis, BCP-ALL or mixed phenotype acute leukemia (MPAL) and defined as a new subtype of ALL. In this study, we screened 42 MPAL and 91 BCP-ALL patients for the most common ZNF384 fusions; ZNF384::TCF3, ZNF384::EP300 and ZNF384::TAF15 by using PCR. We identified ZNF384 fusions in 9.5% of MPAL and 7.6% of BCP-ALL. A novel breakpoint was identified in ZNF384::TCF3 fusion in one BCP-ALL patient. T-myeloid MPAL patients showed significantly lower ZNF384 expression compared to lymphoid groups. Patients with ZNF384r had intermediate survival rates based on other subtypes. Prognostic and patient-specific treatment evaluation of ZNF384 fusions in both ALL and MPAL might help to improve risk characterization of patients.

Deferasirox in children with transfusion-dependent thalassemia or sickle cell anemia: A large cohort real-life experience from Turkey (REACH-THEM).

OBJECTIVES: To evaluate the long-term efficacy and safety of deferasirox therapy in a large observational cohort of children with transfusion-dependent thalassemia (TDT) and sickle cell anemia (SCA) in Turkey. METHODS: This was a multicenter, prospective cohort study including TDT and SCA patients aged 2-18 years with iron overload (≥100 mL/kg of pRBC or a serum ferritin [SF] level >1000 µg/L) receiving deferasirox. Patients were followed for up to 3 years according to standard practice. RESULTS: A total of 439 patients were evaluated (415 [94.5%] TDT, 143 [32.6%] between 2 and 6 years). Serum ferritin levels consistently and significantly decreased across 3 years of deferasirox therapy from a median of 1775.5 to 1250.5 µg/L (P < 0.001). Serum ferritin decreases were noted in TDT (1804.9 to 1241 µg/L), SCA (1655.5 to 1260 µg/L), and across age groups of 2-6 years (1971.5 to 1499 µg/L), 7-12 years (1688.5 to 1159.8 µg/L), and 13-18 years (1496.5 to 1107 µg/L). Serum ferritin decreases were also noted for all deferasirox dose groups but only significant in patients with doses ≥30 mg/kg/d (n = 120, -579.6 median reduction, P < 0.001). Only 9 (2%) patients had adverse events suspected to be related to deferasirox. Serum creatinine slightly increased but remained within the normal range. CONCLUSIONS: Deferasirox has long-term efficacy and safety in children with TDT and SCA, although higher doses (≥30 mg/kg/d) may be required to achieve iron balance.

Assessment of Nutritional Status and Malnutrition Risk at Diagnosis and Over a 6-Month Treatment Period in Pediatric Oncology Patients With Hematologic Malignancies and Solid Tumors.

In total, 74 pediatric oncology patients with hematologic malignancies (n=56) or solid tumors (n=18) and a median age of 78.5 months were included in this prospective study. The aims were to assess malnutrition risks and nutritional status over a 6-month treatment period measured at regular intervals. The rate of patients with high risk for malnutrition at diagnosis was 28.4% by Screening Tool for Risk of Impaired Nutritional Status and Growth tool and 36.5% by Pediatric Yorkhill Malnutrition Score. Body mass index (BMI) z-scores at diagnosis showed 12.3% undernutrition (<-2 SD) and 6.8% overnutrition (>2 SD), which changed to 6.7% and 11.1% at the sixth month, respectively. Malnutrition (BMI<5th age percentile) was detected in 13.7% at diagnosis. Despite an initial deterioration noted in BMI, BMI for age percentile, and z-scores at month 1 in all malignancy subgroups (at month 3 for acute lymphoblastic leukemia), the scores improved later on. There was an increase in weight from baseline in 88.2% of patients over 6 months. This study revealed a decrease in the prevalence of undernutrition and malnutrition over a 6-month treatment period with improved anthropometrics despite an initial deterioration in all malignancy subgroups and even in patients with high risk for malnutrition at baseline screening. Solid tumors and acute lymphoblastic leukemia seem to be associated with higher likelihood of undernutrition and overnutrition, respectively, during treatment.

Use of a High-Purity Factor X Concentrate in Turkish Subjects with Hereditary Factor X Deficiency: Post Hoc Cohort Subanalysis of a Phase 3 Study.

Hereditary factor X (FX) deficiency is a rare bleeding disorder more prevalent in countries with high rates of consanguineous marriage. In a prospective, open-label, multicenter phase 3 study, 25 IU/kg plasma-derived factor X (pdFX) was administered as on-demand treatment or short-term prophylaxis for 6 months to 2 years. In Turkish subjects (n=6), 60.7% of bleeds were minor. A mean of 1.03 infusions were used to treat each bleed, and mean total dose per bleed was 25.38 IU/kg. Turkish subjects rated pdFX efficacy as excellent or good for all 84 assessable bleeds; investigators judged overall pdFX efficacy to be excellent or good for all subjects. Turkish subjects had 51 adverse events; 96% with known severity were mild/moderate, and 1 (infusion-site pain) was possibly pdFX-related. These results demonstrate that 25 IU/kg pdFX is safe and effective in this Turkish cohort (ClinicalTrials.gov identifier: NCT00930176).

Chylous ascites after lymphadenectomy in a Wilms` tumor patient.

Yörük MA, Erat-Nergiz M, Timur Ç, Canbolat-Ayhan A, Ergüven M. Chylous ascites after lymphadenectomy in a Wilms` tumor patient. Turk J Pediatr 2018; 60: 436-438. Wilms` tumor is the most common renal malignancy in children and the fourth most common childhood cancer. It accounts 6-7% of all childhood malignancies. Surgical resection is an important therapy option and transabdominal or transperitoneal resection with lymph node sampling is preferred. Development of chylous ascites following intraabdominal or retroperitoneal resection in pediatric age group generally results from extensive lymph node dissection, accidental ligation or interruption of lymphatic ducts. Diseases or conditions affecting abdominal and/or retroperitoneal lymph nodes may cause chylous ascites. Postoperative chylous ascites is associated with significant morbidity and may cause mechanic, nutritional and immunological complications. In the present study, a 16-month-old infant with Stage IV Wilms` tumor who developed chylous ascites after left nephrectomy and lymphadenectomy will be presented; chylous ascites treatment with enteral nutrition and surgical treatment approach for Wilms` tumor will be reviewed.

Effects of Malnutrition on Neutrophil/Mononuclear Cell Apoptotic Functions in Children with Acute Lymphoblastic Leukemia.

BACKGROUND: Recent studies claim that apoptosis may explain immune dysfunction observed in malnutrition. OBJECTIVE: The objective of this study was to determine the effect of malnutrition on apoptotic functions of phagocytic cells in acute lymphoblastic leukemia (ALL). MATERIALS AND METHODS: Twenty-eight ALL patients (13 with malnutrition) and thirty controls were enrolled. Neutrophil and mononuclear cell apoptosis of ALL patients and the control group were studied on admission before chemotherapy and repeated at a minimum of three months after induction of chemotherapy or when the nutritional status of leukemic children improved. RESULTS: The apoptotic functions of both ALL groups on admission were significantly lower than those of the control group. The apoptotic functions were lower in ALL patients with malnutrition than those in ALL patients without malnutrition, but this was not statistically significant. The repeated apoptotic functions of both ALL groups were increased to similar values with the control group. This increase was found to be statistically significant. CONCLUSIONS: The apoptotic functions in ALL patients were not found to be affected by malnutrition. However, after dietary intervention, increased apoptotic functions in both ALL patient groups deserve mentioning. Dietary intervention should always be recommended as malnutrition or cachexia leads to multiple complications. Enhanced apoptosis might originate also from remission state of cancer.

A retrospective analysis of complications observed in children with acute lymphoblastic leukemia during chemotherapy.

BACKGROUND: We aimed to evaluate the complications that we observed in children with acute lymphoblastic leukemia (ALL) during the remission induction, consolidation, and reinduction phases of chemotherapy retrospectively. METHODS: We analysed the clinical records of 128 patients with ALL who were diagnosed and treated in the Department of Pediatric Hematology of Istanbul Medeniyet University Goztepe Training Hospital between August 2009 and April 2014 to document the acute complication other than febrile neutropenia episodes, which developed during the induction, consolidation and reinduction phases of chemotherapy. RESULTS: We documented 279 complications. Of these, 53.05% were in males, 46.95% in females; 32.26% were in standard-risk, 45.52% in medium-risk, 22.22% in high-risk group of patients. Common documented events were pneumonia (25%), therapy-induced hyperglycemia (16.40%) therapy-related hepatitis (15.6%), generalized tonic-clonic seizures (14.8%), anaphylaxis to asparaginase (14.1%), hypertension (13.3%) varicella zoster virus (VZV) infection (13.3%), renal tubulopathy (12.5%). Time of complications was induction phase in 32.62%, consolidation in 19.35%, HR blocks in 18.28%, reinduction 29.75% during the phases. Mortality rate due to complications was 13.28%. CONCLUSIONS: Therapy-related complications can limit the survival rates in children with ALL. To minimize the treatment burden, even very rare complications must be considered and treated promptly with a multidisciplinary approach.

Evaluation of Alpha-Thalassemia Mutations in Cases with Hypochromic Microcytic Anemia: The Istanbul Perspective.

OBJECTIVE: Alpha thalassemia syndromes are caused by mutations on one or more of the four α-globin genes. Mutations could be either more commonly deletional or non-deletional. As some deletions (3.7 and 4.2) cause α+-thalassemia, some cause (-20.5, MED, THAI, FIL) α0 -thalassemia. The aim of this study was to determine alpha thalassemia mutations in patients with unsolved hypochromic microcytic anemia and to evaluate types of mutations. MATERIAL AND METHODS: Two hundred six patients with hypochromic microcytic anemia were evaluated for alpha thalassemia. A venous blood sample of 2 mL was drawn from each patient for DNA isolation. The samples were investigated for α-thalassemia mutations by using the Vienna Lab α-Globlin StripAssay TM commercial kit. RESULTS: Fourteen different mutations were determined in 95 (46.1%) patients. The most common mutation was the 3.7 single gene deletion and was found in 37 patients (n=37/95, 39%). Others common mutations were the 20.5 kb double gene deletion (n=20 patients, 21%), MED double gene deletion (n=17 patients, 17.9%), α2 IVS1 (n=10 patients, 10.5%), α2 cd142 Hb Koya Dora (n=6 patients, 6.3%), α2 polyA1 (Saudi type) (n=6 patients, 6.3%), 4.2 single gene deletion (n=4 patients, 4.2%), α1 cd14 (n=2 patients, 2.1%), and -FIL mutation (n=2 patients 2.1%), respectively. Hb Adana, Hb Icaria, α2 init cd and α2 polyA2 (Turkish type) were found in 1% of the patients (n=1). Seven patients (7.4%) had α-thalassemia triplication. In our study, three mutations (Hb Icaria, α1 cd14, α2 init.cd) were determined firstly in Turkey. Seven mutations (-SEA, -THAI, Hb Constant Spring, α2 cd19, α2 cd59, α2 cd125, Hb Paksé) were not determined in this study. CONCLUSION: Alpha thalassemia should be considered in the differential diagnosis of hypochromic microcytic anemia especially in cases without iron deficiency and b-thalassemia carrier state. Genetic testing should be performed for the suspicious cases. We also recommend that a national database with all mutations in Turkey should be created to screen the alpha thalassemia cost-effectively.

A Possible Role for WNT5A Hypermethylation in Pediatric Acute Lymphoblastic Leukemia.

OBJECTIVE: WNT5A is one of the most studied noncanonical WNT ligands and is shown to be deregulated in different tumor types. Our aim was to clarify whether hypermethylation might be the cause of low WNT5A mRNA levels and whether we could restore this downregulation by reversing the event. MATERIALS AND METHODS: The expression of WNT5A mRNA was studied in a large acute lymphoblastic leukemia (ALL) patient group (n=86) by quantitative real-time PCR. The methylation status was detected by methylation-specific PCR (MSPCR) and bisulphate sequencing. In order to determine whether methylation has a direct effect on WNT5A expression, disease-representative cell lines were treated by 5'-aza-20-deoxycytidine. RESULTS: Here we designed a validation experiment of the WNT5A gene, which was previously examined and found to be differentially expressed by microarray study in 31 T-cell ALL patients. The expression levels were confirmed by quantitative real-time PCR and the expression levels were significantly lower in T-cell ALL patients than in control thymic subsets (p=0.007). MSPCR revealed that 86% of the patients were hypermethylated in the WNT5A promoter region. Jurkat and RPMI cell lines were treated with 5'-aza-20-deoxycytidine and WNT5A mRNA expression was restored after treatment. CONCLUSION: According to our results, WNT5A hypermethylation does occur in ALL patients and it has a direct effect on mRNA expression. Our findings show that epigenetic changes of WNT signaling can play a role in ALL pathogenesis and reversing methylation might be useful as a possible treatment of leukemia.

Changes in platelet indices in children with bicuspid aortic valve.

Mean platelet volume (MPV) and platelet distribution width (PDW) can help diagnose cardiovascular pathologies. In this study, we aimed to demonstrate the changes in platelet (PLT) indices in children diagnosed with bicuspid aortic valve (BAV) with mild stenosis and without stenosis to compare patients with mild stenosis with those without stenosis. A total of 73 children diagnosed with BAV (30 patients with mild stenosis and 43 without stenosis) with a mean age 9.73 ± 5.01 years and a control group were included in the study. Mean MPV value was significantly lower in the control group compared with patients with BAV with mild stenosis and patients without stenosis (p = 0.001, and p < 0.01, respectively). MPV was significantly greater in patients with mild stenosis than in patients without stenosis (p = 0.049 and p < 0.05, respectively). Patients with mild stenosis had a significantly greater mean PDW value compared with patients without stenosis and the control group (p = 0.024 and p < 0.05, respectively). There was no significant difference between patients without stenosis and the control group with respect to mean PDW value (p > 0.05). In conclusion, the results of this study demonsrate that children with BAV either with or without stenosis have increased MPV; the ones with mild stenosis have even greater values than the ones without stenosis. It emphasizes the risk of thrombosis in children with BAV.

Myeloid sarcoma presenting with leukemoid reaction in a child treated for acute lymphoblastic leukemia.

Background. Myeloid sarcoma is an extramedullary neoplasm of immature myeloid cells. Our study reports a presentation of myeloid sarcoma which presented with severe leukemoid reaction as a secondary malignancy in a patient who was treated for acute lymphoblastic leukemia previously. The case emphasizes the difficulties in diagnosis of patients who do not have concomitant leukemia. Case Presentation. A 6-year-old girl who was treated for acute lymphoblastic leukemia previously presented with fatigue, paleness, and hepatosplenomegaly. Peripheral blood smear and bone marrow aspirate examination did not demonstrate any blasts in spite of severe leukemoid reaction with a white cell count 158000/mm(3). FDG/PET CT revealed slight uptake in cervical and supraclavicular lymph nodes. Excisional lymph node biopsy was performed from these lymph nodes and it showed myeloid sarcoma. Conclusion. Myeloid sarcoma can develop as a secondary malignancy in children who are treated for acute lymphoblastic leukemia. It can be associated with severe leukemoid reaction and diagnosis may be difficult if there is not concomitant leukemia. PET/CT is helpful in such cases.

Spontaneous intestinal perforation: an atypical presentation of neutropenic enterocolitis-a case report.

Background. Neutropenic enterocolitis is one of the most common gastrointestinal complications seen in patients who are receiving chemotherapy for leukemia. Severe neutropenia is the main underlying factor of this pathology. It is characterized by fever and abdominal pain. Case Presentation. Herein, we report a case of neutropenic enterocolitis which presented with intestinal perforation in an afebrile patient who was diagnosed with acute lymphoblastic leukemia and was receiving induction chemotherapy. Conclusion. We aimed to emphasize the importance of enterocolitis and increase awareness against such severe complications which could have unexpected presentations.

A trombosis story and PRES.

Trombosis is seen in children with acute lymphoblastic leukemia during or after L-asparaginase treatment. Posterior reversible encephalopathy syndrome (PRES) is a complex syndrome characterized with sudden hypertension, headache, nausea, vomiting, alteration in the state of consciousness, vision defect and seizures. The cases related to this syndrome have been reportedly seen after eclampsia, organ transplantation, immunsuppressive treatments, autoimmune diseases and chemotherapy. Vasogenic edema occuring in the brain parencyhma constitues the basic pathophysiology. We present a case who developed seizures during treatment for B-cell acute lymphoblastic leukemia and diagnosed as posterior reversible encephalopathy.

Chronic granulomatous Aspergillus synovitis: a case report.

Aspergillus can cause invasive disease of various organs especially in patients with weakened immune systems. Aspergillus synovitis and arthritis are uncommon types of involvement due to this infection. Approaches to fungal osteoarticular infections are based on only case reports. This paper presents a rare case of chronic granulomatous Aspergillus synovitis in an immunocompromised 5-year old girl who was treated for acute lymphoblastic leukemia.

Frequency of pericardial effusion in childhood acute lymphoblastic leukemia and clinical features of these patients.

In this study, we aimed to determine the frequency of pericardial effusion (PE) in children diagnosed with acute lymphoblastic leukemia (ALL). Clinical features of patients with effusion were evaluated. For this purpose, we reviewed the medical records of ALL patients who had pretherapy echocardiograms. A total of 90 patients aged between 1.8 and 16.3 years were analyzed retrospectively. In 23 of 90 (25.6%) patients, PE was detected at initial diagnosis. The age of patients with PE ranged between 1.8 and 14.8 years (mean 5.05 ± 3.77 years). The female/male ratio was 9/14. Six (26.1%) patients were T-lineage and 17 (73.9%) were B-lineage ALL. Nine (39%) patients were in standard risk group, 13 (57%) were in median risk group, 1 (4%) patient was in high-risk group. Mean initial white blood cell count was 40.756 ± 38.653/mm(3) (range 23.000-130.000/mm(3)). Mean initial hemoglobin count was 7.3 ± 1.39 gr/dL (range 5.5-10.1 gr/dL), mean initial platelet count was 35.200 ± 26.300/mm(3) (range 4.000-118.000 mm(3)). Size of effusions was between 2 and 6 mm (mean size 3.3 ± 1.8 mm). All patients had normal left ventricular systolic function. In 87% of patients, effusions disappeared in the first 7 days and, in 13%, disappeared between 8th and 15th days of chemotherapy. None of the patients required pericardiocentesis. Cardiac dysfunction did not occur among any of these patients during chemotherapy. In conclusion, PE is not frequent in childhood ALL. It usually does not cause cardiac impairment. It responds to treatment of leukemia.

Seroconversion status after single dose and double doses of varicella vaccination in children with leukemia.

Although varicella is a benign self-limiting disease in healthy children, it can be fatal when it occurs in immunocompromised hosts. Despite that immunosuppressed children are suggested to require 2 doses of vaccine to achieve seroconversion, conflicting results are reported in the literature. The aim of this study was to investigate the seroconversion status and mean antibody titers at first year after single dose and double doses of varicella vaccination in acute lymphoblastic leukemia patients. Patients with leukemia in remission for at least 1 year who were seronegative for varicella-zoster virus immunoglobulin G (IgG) were vaccinated. Titers above the cutoff level (0.65) were accepted as seroconversion. Seventeen patients were vaccinated with single dose whereas 24 patients were vaccinated with double doses. Mean prevaccination antibody titers were 0.56 ± 0.05 in patients with single dose and 0.51 ± 0.08 in patients with double doses (P > .05, Student t test). The mean antibody titers at first year were 0.61 ± 0.05 in patients with single-dose vaccination (P > .05, Wilcoxon signed-rank test) and 1.48 ± 0.04 in patients with double doses (P < .001, Wilcoxon signed-rank test). Seroconversion after single-dose vaccination was achieved in 29% of patients (n = 5/17) and in 75% of patients with double doses (n = 18/24) at first year (P = .004, chi-square test). These results suggest that seroconversion after single-dose vaccination might not persist at first year in malignancy patients. Double doses should be applied in order to provide long-term seroconversion.