Genetic Profiling of Pediatric Patients with B-Cell Precursor Acute Lymphoblastic Leukemia.

B-cell precursor acute lymphoblastic leukemia (BCP-ALL) is a heterogeneous leukemia subgroup. It has multiple sub-types that are likely to be classified by prognostic factors. Following a systematic literature review, this study analyzed the genes correlated with BCP-ALL prognosis ( IKZF1, PAX5, EBF1, CREBBP, CRLF2, JAK2, ERG, CXCR4, ZAP70, VLA4, NF1, NR3C1, RB1, TSLP, ZNRF1, and FOXO3A) , specifically their nucleotide variations and expression profiles in pediatric BCP-ALL samples. The study included 45 pediatric BCP-ALL patients with no cytogenetic anomaly and a control group of 10 children. The selected genes' hot-spot regions were sequenced using next-generation sequencing, while Polymorphism Phenotyping v2 and Supplemental Nutrition Assistance Program were used to identify pathogenic mutations. The expression analysis was performed using quantitative real-time polymerase chain reaction. The mutation analysis detected 328 variants (28 insertions, 47 indels, 74 nucleotide variants, 75 duplications, and 104 deletions). The most and least frequently mutated genes were IKZF1 and CREBBP , respectively. There were statistically significant differences between patients and controls for mutation distribution in eight genes ( ERG, CRLF2, CREBBP, TSLP, JAK2, ZAP70, FOXO3A, and NR3C1 ). The expression analysis revealed that JAK and ERG were significantly overexpressed in patients compared with controls (respectively, p = 0.004 and p = 0.003). This study combined genes and pathways previously analyzed in pediatric BCP-ALL into one dataset for a comprehensive analysis from the same samples to unravel candidate prognostic biomarkers. Novel mutations were identified in all of the studied genes.

Thalassemia-free and graft-versus-host-free survival: outcomes of hematopoietic stem cell transplantation for thalassemia major, Turkish experience.

We report the national data on the outcomes of hematopoietic stem cell transplantation (HSCT) for thalassemia major (TM) patients in Turkey on behalf of the Turkish Pediatric Stem Cell Transplantation Group. We retrospectively enrolled 1469 patients with TM who underwent their first HSCT between 1988 and 2020 in 25 pediatric centers in Turkey. The median follow-up duration and transplant ages were 62 months and 7 years, respectively; 113 patients had chronic graft versus host disease (cGVHD) and the cGVHD rate was 8.3% in surviving patients. Upon the last visit, 30 patients still had cGvHD (2.2%). The 5-year overall survival (OS), thalassemia-free survival (TFS) and thalassemia-GVHD-free survival (TGFS) rates were 92.3%, 82.1%, and 80.8%, respectively. cGVHD incidence was significantly lower in the mixed chimerism (MC) group compared to the complete chimerism (CC) group (p < 0.001). In survival analysis, OS, TFS, and TGFS rates were significantly higher for transplants after 2010. TFS and TGFS rates were better for patients under 7 years and at centers that had performed over 100 thalassemia transplants. Transplants from matched unrelated donors had significantly higher TFS rates. We recommend HSCT before 7 years old in thalassemia patients who have a matched donor for improved outcomes.

Hepatosplenic Fungal Infections in Children With Leukemia-Risk Factors and Outcome: A Multicentric Study.

BACKGROUND: Invasive fungal infections, including hepatosplenic fungal infections (HSFI), cause significant morbidity and mortality in children with leukemia. There are not enough data to support for the best approach to diagnosis of HSFI in children, nor for the best treatment. PROCEDURE: In this multicentric study, we assessed the demographic data, clinical and radiologic features, treatment, and outcome of 40 children with leukemia and HSFI from 12 centers. RESULTS: All cases were radiologically diagnosed with abdominal ultrasound, which was performed at a median of 7 days, of the febrile neutropenic episode. Mucor was identified by histopathology in 1, and Candida was identified in blood cultures in 8 patients. Twenty-two had fungal infection in additional sites, mostly lungs. Nine patients died. Four received a single agent, and 36 a combination of antifungals. CONCLUSIONS: Early diagnosis of HSFI is challenging because signs and symptoms are usually nonspecific. In neutropenic children, persistent fever, back pain extending to the shoulder, widespread muscle pain, and increased serum galactomannan levels should alert clinicians. Abdominal imaging, particularly an abdominal ultrasound, which is easy to perform and available even in most resource-limited countries, should be recommended in children with prolonged neutropenic fever, even in the absence of localizing signs and symptoms.

Frequency of thiopurine S-methyltransferase gene variations in Turkish children with acute leukemia.

Akin DF, Aslar-Öner D, Kürekçi E, Akar N. Frequency of thiopurine S-methyltransferase gene variations in Turkish children with acute leukemia. Turk J Pediatr 2018; 60: 147-152. In this study we aim to determine the genotype distribution and allele frequencies of common TPMT (*2, *3A, *3B and *3C) polymorphisms in Turkish children with acute leukemia. The study population consisted of 169 patients aged between 1 and 15 years who were admitted to Losante Pediatric Hematology and Children`s Hospital with the diagnosis of acute leukemia. Genotyping of TPMT polymorphisms was screened with real-time PCR using fluorescence melting curve detection analysis. We found that the frequencies of four allelic variants of TPMT are *2 (238 G > C) (0,0%), *3A (460G > A and 719A > G) (1.7%), *3B (460G > A) (1,7%) and *3C (719A > G) (2.4%). Frequency of TPMT alleles increases the efficacy of leukemia treatment. Thus, TPMT genotyping can be useful for optimizing 6-MP therapy.

Hematopoietic Stem Cell Transplantation Using Preimplantation Genetic Diagnosis and Human Leukocyte Antigen Typing for Human Leukocyte Antigen-Matched Sibling Donor: A Turkish Multicenter Study.

Preimplantation genetic diagnosis involves the diagnosis of a genetic disorder in embryos obtained through in vitro fertilization, selection of healthy embryos, and transfer of the embryos to the mother's uterus. Preimplantation genetic diagnosis has been used not only to avoid the risk of having an affected child, but it also offers, using HLA matching, preselection of potential HLA-genoidentical healthy donor progeny for an affected sibling who requires bone marrow transplantation. Here, we share the hematopoietic stem cell transplantation results of 52 patients with different benign and malign hematological or metabolic diseases or immunodeficiencies whose donors were siblings born with this technique in Turkey since 2008. The median age of the patients' at the time of the transplantation was 8 years (range, 3 to 16 years) and the median age of the donors was 2 years (range, .5 to 6 years). The most common indication for HSCT was thalassemia major (42 of all patients, 80%). The stem cell source in all of the transplantations was bone marrow. In 37 of the transplantations, umbilical cord blood of the same donor was also used. In 50 of the 52 patients, full engraftment was achieved with a mean of 4.6 × 106 CD 34+ cells per kg of recipient weight. Ninety-six percent of the patients have been cured through hematopoietic stem cell transplantation without any complication. Primary engraftment failure was seen in only 2 patients with thalassemia major. All of the donors and the patients are alive with good health status. Preimplantation genetic diagnosis with HLA matching offers a life-saving chance for patients who need transplantation but lack an HLA genoidentical donor.

Holotranscobalamin Levels in Children with Helicobacter pylori Infection.

BACKGROUND: The purpose of this study was to evaluate the association between vitamin B12 levels and Helicobacter Pylori infection and to examine the clinical usefulness of holotranscobalamin (holoTC) measurement in children. MATERIALS AND METHODS: Thirty patients between 6 and 15 years of age, who were diagnosed as H. pylori infected by C(14) urea breath test, and 26 controls were enrolled in the study. Tests for complete blood count, serum vitamin B12 and folate, plasma total homocysteine, and holoTC levels were performed in each patient in the study and control groups. RESULTS: Mean plasma holoTC concentrations were significantly lower in children with H. pylori infection before treatment (median 23.7 pmol/L (12.9-37.1 pmol/L)) versus after treatment (median 38.2 pmol/L (21.2-61.4 pmol/L)) and controls (median 36.1 pmol/L (12.6-58.7 pmol/L)). CONCLUSIONS: The findings of our study suggest that H. pylori infection has a reversible negative effect on vitamin B12 status reflected in a decreased level of plasma holoTC that normalizes upon treatment of the infection, while no change is observed in total plasma vitamin B12 .

Freezing of Apheresis Platelet Concentrates in 6% Dimethyl Sulfoxide: The First Preliminary Study in Turkey.

OBJECTIVE: Transfusion of platelet suspensions is an essential part of patient care for certain clinical indications. In this pioneering study in Turkey, we aimed to assess the in vitro hemostatic functions of platelets after cryopreservation. MATERIALS AND METHODS: Seven units of platelet concentrates were obtained by apheresis. Each apheresis platelet concentrate (APC) was divided into 2 equal volumes and frozen with 6% dimethyl sulfoxide (DMSO). The 14 frozen units of APCs were kept at -80 °C for 1 day. APCs were thawed at 37 °C and diluted either with autologous plasma or 0.9% NaCl. The volume and residual numbers of leukocytes and platelets were tested in both before-freezing and post-thawing periods. Aggregation and thrombin generation tests were used to analyze the in vitro hemostatic functions of platelets. Flow-cytometric analysis was used to assess the presence of frozen treated platelets and their viability. RESULTS: The residual number of leukocytes in both dilution groups was <1x106. The mean platelet recovery rate in the plasma-diluted group (88.1±9.5%) was higher than that in the 0.9% NaCl-diluted group (63±10%). These results were compatible with the European Directorate for the Quality of Medicines quality criteria. Expectedly, there was no aggregation response to platelet aggregation test. The mean thrombin generation potential of post-thaw APCs was higher in the plasma-diluted group (2411 nmol/L per minute) when compared to both the 0.9% NaCl-diluted group (1913 nmol/L per minute) and the before-freezing period (1681 nmol/L per minute). The flow-cytometric analysis results for the viability of APCs after cryopreservation were 94.9% and 96.6% in the plasma and 0.9% NaCl groups, respectively. CONCLUSION: Cryopreservation of platelets with 6% DMSO and storage at -80 °C increases their shelf life from 7 days to 2 years. Besides the increase in hemostatic functions of platelets, the cryopreservation process also does not affect their viability rates.

Anticardiolipin Antibodies in Children with Helicobacter pylori Infection.

BACKGROUND: Anticardiolipin (aCL) antibodies are associated with thrombosis and have an important role in the etiology of diseases such as stroke and myocardial infarction whose etiologies were based on thrombosis. H. pylori has been proposed to be responsible for the pathophysiology of some diseases including stroke, myocardial infarction, thrombosis, and autoimmune diseases. From this point of view, we hypothesized a possible relationship between H. pylori infection and aCL antibodies and initially aimed to determine the prevalence of aCL antibody positivity in children with H. pylori infection. MATERIALS AND METHODS: Anticardiolipin antibodies were studied in 84 patients before and after eradication therapy and in a control group including 40 children. RESULTS: The pretreatment aCL IgA (median 12.78 APL/mL), aCL IgM (median 21.60 MPL/mL), and aCL IgG antibody levels (median 14.22 GPL/mL) were significantly higher than those of post-treatment results (median 5.38 APL/mL, 7.02 MPL/mL, and 6.64 GPL/mL, respectively) and controls (median 5.90 APL/mL, 4.80 MPL/mL, and 4.81 GPL/mL, respectively). Anticardiolipin antibodies revealed no significant differences between the study group after therapy and the control group. CONCLUSIONS: In our particular experience, H. pylori can cause aCL antibody positivity in children and eradication of H. pylori provides the disappearance of these antibodies.

Blood parameters changes in cord blood of newborns of hypertensive mothers.

UNLABELLED: The aim of this study was to investigate the changes in the peripheral blood of newborns of hypertensive mothers. The umbilical cord blood from newborns of 31 hypertensive mothers and 32 healthy mothers were examined. In all subjects, complete blood count, peripheral blood smear, reticulocyte count, vitamin B12, folate, ferritin levels and hemoglobin electrophoresis were performed. The subjects were followed up on for 1 year in terms of infections. RBC, hemoglobin, reticulocyte count and normoblast count were higher in the newborns of hypertensive mothers compared to the control group, and total leukocytes, neutrophil, lymphocyte, monocyte, eosinophil, and thrombocyte counts were lower. The number of neutropenic and thrombocytopenic subjects in newborns of hypertensive mothers was higher compared to the control group. On peripheral smears, dysplastic changes in neutrophils and erythrocytes were observed with a higher rate in newborns of hypertensive mothers compared to the control group. HbF levels were found to be higher in newborns of hypertensive mothers compared to the control group. During the follow-up period of 1 year, the number of infections in newborns of hypertensive mothers was found to be higher than the control group. CONCLUSION: Newborns of hypertensive mothers should be carefully evaluated and monitored in terms of hematologic abnormalities. Complete blood counts and peripheral blood smears can be used as significant parameters for early diagnosis of possible complications.

Factor V Leiden and Prothrombin 20210A Mutations among Turkish Pediatric Leukemia Patients.

This study was undertaken to determine the prevalence of the Factor V 1691 G-A and PT 20210 G-A mutations in Turkish children with leukemia. We genotyped 135 pediatric leukemia patients with for these mutations. Eleven (8%) of the 135 patients were heterozygous for the FV 1691 G-A mutation. Seven (5,1%) of the patients carried the PT 20210 G-A heterozygous mutation. Of the 135 patients, only three had thrombotic event, none of which had these two mutations, which is common in Turkish population. Our findings revealed a controversial compared to the previous reports, which needs further investigation.

HLA-matched family hematopoetic stem cell transplantation in children with beta thalassemia major: the experience of the Turkish Pediatric Bone Marrow Transplantation Group.

From January 1991 to June 2009, 245 children with beta thalassemia major who underwent their first allogeneic HSCT in Turkey and who were followed for a minimum of one yr post-transplantation were enrolled this study. The median age of the patients was 6.6 yr old (range, 1-22 yr). The distribution of Pesaro risk class I, II, and III categories was 41, 130, and 63 children, respectively. The median serum ferritin level was 2203 ng/mL. Eighty-eight patients received bone marrow (BM) stem cells; 137, peripheral blood (PB) stem cells; and 20, cord blood (CB) stem cells. The donors were HLA-matched siblings or parents. Median engraftment times were shorter in PBSCT patients compared with the BMT group (p < 0.001). Grade II-IV acute GvHD was observed in 33 children (13.5%), while cGvHD was observed in 28 patients (12.5%), eight of whom had the extensive form. Thalassemic reconstitution was observed in 43 (17%) of the transplant patients. Post-transplant aplasia occurred in three patients, and the TRM rate was 7.75%. Seventeen patients were lost after 100 days. The thalassemia-free survival and OS rates were 68% (95% CI, 61.8-74.2) and 85.0% (95% CI, 80.2-89.8), respectively. We believe that this study is important because it is the first multicenter national data for children with beta thalassemia major receiving HSCT.

Successful treatment of ICE-rituximab chemotherapy and subsequent bone marrow transplantation in a patient with early-relapse Burkitt leukemia and inverted duplication of 1q.

Although childhood acute lymphoblastic leukemias are of good prognosis than leukemias of adulthood, some chromosomal abnormalities may have negative effects on their prognosis. Inverted duplication (1q) is a chromosomal abnormality with negative effect on outcome of Burkitt leukemia and lymphomas. We report a case of CD20 Burkitt leukemia with inverted duplication (1q) mutation, who had an early relapse during NHL-BFM 95 treatment. Two courses of ICE-rituximab treatment were administered after relapse and a successful HLA-full match bone marrow transplantation was carried out. He is in follow-up for 18 months without any problem after the bone marrow transplantation. We suggest the usage of ICE protocol combined with rituximab in childhood CD20 Burkitt leukemia with poor prognostic criteria such as inverted duplication (1q) mutation.

Rare coagulation disorders: a retrospective analysis of 156 patients in Turkey.

OBJECTIVE: To retrospectively evaluate the clinical findings, laboratory data, management, and outcome in a group ofTurkish children diagnosed with rare coagulation deficiencies (RCDs) between January 1999 and June 2009. MATERIAL AND METHODS: The Turkish Society of Pediatric Hematology-Hemophilia-Thrombosis-Hemostasissubcommittee designed a Microsoft Excel-based questionnaire for standardized data collection and sent it to participatinginstitutions. RESULTS: In total, 156 patients from 12 pediatric referral centers were included in the study. The cost common RCDswere as follows: FVII (n = 53 [34%]), FV (n = 24 [15.4%]), and FX (n = 23 [14.7%]) deficiency. The most common initialfinding in the patients was epistaxis, followed by ecchymosis, and gingival bleeding. CONCLUSION: Initial symptoms were mucosal bleeding, and fresh frozen plasma (FFP) and tranexamic acid werethe most commonly used treatments. We think that prophylactic treatment used for hemophilia patients should beconsidered as an initial therapeutic option for patients with rare factor deficiencies and a severe clinical course, and forthose with a factor deficiency that can lead to severe bleeding.

Two new mutations at ERGIC-53 gene in a Turkish family.

Combined factor V and factor VIII deficiency (F5F8D) is a rare autosomal recessive coagulation disorder associated with plasma levels of coagulation factors V and VIII approximately 5% to 30% normal. Combined factor V and factor VIII deficiency is caused by mutations in ERGIC-53 (LMAN1) gene. ERGIC-53 and multiple coagulation factor deficiency 2 (MCFD2) form a protein complex that functions as a cargo receptor transport FV and FVIII from the endoplasmic reticulum to the Golgi. The aim of this study was to determine the mutations of ERGIC-53 (endoplasmic reticulum [ER] to the ER-Golgi intermediate compartment) gene and combined F5F8D in a family. In this study, we analyzed a patient in a Turkish family with combined F5F8D. We found a nonsense mutation of C to T at nucleotide 202 in exon 9, resulting in a transition of arginine to stop codon, and in 1 child, we found a timine deletion in exon 4 in ERGIC-53 gene.

Chronic bullous disease of childhood in a patient with acute lymphoblastic leukemia: possible induction by a drug.

Linear IgA disease is characterized by the presence of linear IgA deposits in the basement membrane zone of the skin, and circulating basement membrane zone antibodies are detected in 80% of cases. The disease occurs in both adults and children, and is designated adult linear IgA disease in the former and chronic bullous disease of childhood (CBDC) in the latter. We describe a 5-year-old boy with acute lymphoblastic leukemia in remission, in whom CBDC developed after treatment with trimethoprim/sulfamethoxazole (cotrimoxazole). To our knowledge, this is the first reported case of possible drug-induced CBDC.

Budd-Chiari syndrome in a child due to a membranous web of the inferior vena cava resolved by systemic and local recombinant tissue plasminogen activator treatment.

Budd-Chiari syndrome is a heterogeneous group of disorders characterized by hepatic venous outflow obstruction. Although there are no guidelines for treatment of patients with Budd-Chiari syndrome, thrombolytic therapy may be useful in patients with acute Budd-Chiari syndrome. In this report, a boy with Budd-Chiari syndrome due to membranous obstruction of the inferior vena cava treated with systemic and local administration of recombinant tissue plasminogen activator is described. We would like to emphasize the role of systemic and local fibrinolytic treatment in these patients.

Analysis of pediatric thrombotic patients in Turkey.

This study analyzes the data of thrombotic children who were followed up in different pediatric referral centers of Turkey, to obtain more general data on the diagnosis, risk factors, management, and outcome of thrombosis in Turkish children. A simple two-page questionnaire was distributed among contact people from each center to standardize data collection. Thirteen pediatric referral centers responded to the invitation and the total number of cases was 271. All children were diagnosed with thromboembolic disease between January 1995 and October 2001. Median age at time of first thrombotic event was 7.0 years. Of the children 4% of the cases were neonates, 12% were infants less than 1 year old, and 17% were adolescents. Thromboembolic event was mostly located in the cerebral vascular system (32%), deep venous system of the limbs, femoral and iliac veins (24%), portal veins (10%), and intracardiac region (9%). Acquired risk factors were present in 86% of the children. Infection was the most common underlying risk factor. Inherited risk factors were present in 30% of the children. FVL was the most common inherited risk factor. Acquired and inherited risk factors were present simultaneously in 19% of the patients. Eleven children had a history of familial thrombosis. Due to the local treatment preferences, the treatment of the children varied greatly. Outcome of the 142 patients (52%) was reported: 88 (62%) patients had complete resolution, 47 (33%) had complications, 12 (9%) had recurrent thrombosis, and 34 (24%) died. Three children (2.1%) died as a direct consequence of their thromboembolic disease. The significant morbidity and mortality found in this study supports the need for multicentric prospective clinical trials to obtain more generalizable data on management and outcome of thrombosis in Turkish children.