The association of HLA-DRB1 alleles and MBL2 gene variant in pediatric acute lymphoblastic leukemia patients.

INTRODUCTION: Epidemiologic studies on pediatric acute lymphoblastic leukemias (ALL) have been conducted to evaluate the possible risk factors including genetic, infectious and environmental factors with the objective of idenfying the etiology. Mannose-binding lectin 2 (MBL2) plays an important role in first-line immune defense. HLA DRB1 alleles play a role in presentation of peptides to T cells and in activation of the adaptive immune response. OBJECTIVE: In our study, we aimed to investigate both the MBL2 gene variant and HLA-DRB1 alleles in pediatric ALL patients. MATERIALS: In this study, 86 high-risk ALL patients and 100 controls were included. Polymerase Chain Reaction (PCR)-Restriction Fragment Length Polymorphism (PCR-RFLP) and PCR-sequence specific primer (SSP) methods were used for detection of polymorphism of the MBL2 and HLA-DRB1 alleles, respectively. RESULTS: The frequency of the MBL2 AB genotype was lower in female ALL patients, compared to male ALL patients (p = 0.034). An association was found between the MBL2 BB genotype and DRB1*07 and among patients with the MBL2 BB genotype; those who also carried the DRB1*07 and *04 alleles were significantly higher than those without the DRB1*07 and *04 alleles. (p = 0.048, p = 0.022, respectively). CONCLUSION: This is the first study suggesting that the MBL2 BB genotype in association with the DRB1*07 or co-inheritance of the HLA-DRB1*04 and HLA DRB1*07 may have an impact on the etiopathogenesis of the disease.

Prognostic Factors and Long-term Outcomes in 41 Children With Primary Hemophagocytic Lymphohistiocytosis: Report of a Single-center Experience and Review of the Literature.

Hemophagocytic lymphohistiocytosis (HLH) is a rare life-threatening hyperinflammatory syndrome with diverse clinical manifestations leading to major diagnostic and therapeutic difficulties. This study aimed to evaluate clinical manifestations, prognostic factors, and long-term outcomes in children with primary HLH. Forty-one patients diagnosed with primary HLH were retrospectively evaluated for patient characteristics, HLH gene mutations, clinical and laboratory manifestations, prognostic factors, and long-term outcomes. The median age of the patients at the time of diagnosis was 3 months (minimum to maximum: 1 to 144 mo). There were 23 patients who had HLH mutation analysis performed, 10 patients with PRF1 mutation, 6 with STX11 mutation, and 7 with UNC13D mutation. Thirteen patients (31.7%) had central nervous system involvement. No correlation was found between overall survival and central nervous system involvement. The estimated 5-year overall survival for the patient who had hematopoietic stem cell transplantation was 9.4 times better than the patients who did not receive hematopoietic stem cell transplantation (81.3% vs 16.7%; P = 0.001). Median serum sodium and blood urea nitrogen levels were significantly higher in deceased HLH patients compared with surviving HLH patients ( P = 0.043, and P = 0.017, respectively). Primary HLH has a poor outcome with high mortality, which necessitates well-designed and international clinical trials to improve diagnosis, therapy, and long-term outcomes.

Clinical Features and Outcome of Children With Hereditary Spherocytosis.

OBJECTIVE: The aim of this study was to evaluate the demographics, clinical, and laboratory findings and treatment responses of patients with hereditary spherocytosis (HS). MATERIALS AND METHODS: Data of children with HS were examined. Diagnosis was based on clinical history, physical examination, family history, presence of spherocytes on peripheral blood smear, and osmotic fragility test. RESULTS: A total of 101 patients were included. The median (range) age at diagnosis was 38.0 (1 to 188) months. Mild, moderate, and severe forms of HS were present in 29 (28.7%), 15 (14.9%), and 57 (56.4%) patients, respectively. Family history was available in 73 patients and 56 of these (76.7%) had a positive family history for HS. Forty-five (44.5%) patients needed regular transfusions and all of these had severe disease. Although most patients did not require transfusion postsplenectomy, 2 of 45 (4.4%) patients continued to require transfusion. Transfusion dependence was significantly (P<0.001) higher in patients with severe spherocytosis. CONCLUSIONS: In HS, splenomegaly, pallor, and jaundice are the most common clinical features. Splenectomy dramatically reduces hemolysis in most cases and virtually abolishes further requirement for transfusion.

Different Kinetics and Risk Factors for Isolated Extramedullary Relapse after Allogeneic Hematopoietic Stem Cell Transplantation in Children with Acute Leukemia.

Relapse after allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains the most frequent cause of post-transplantation mortality. Isolated extramedullary (EM) relapse (iEMR) after HSCT is relatively rare and not well characterized, particularly in pediatric patients. We retrospectively analyzed 1527 consecutive pediatric patients with acute leukemia after allo-HSCT to study the incidence, risk factors, and outcome of iEMR compared with systemic relapse. The 5-year cumulative incidence of systemic relapse (either bone marrow [BM] only or BM combined with EMR) was 24.8%, and that of iEMR was 5.5%. The onset of relapse after allo-HSCT was significantly longer in EM sites than in BM sites (7.19 and 5.58 months, respectively; P = .013). Complete response (CR) 2+/active disease at transplantation (hazard ratio [HR], 3.1; P < .001) and prior EM disease (HR, 2.3; P = .007) were independent risk factors for iEMR. Chronic graft-versus-host disease reduced the risk of systemic relapse (HR, 0.5; P = .043) but did not protect against iEMR. The prognosis of patients who developed iEMR remained poor but was slightly better than that of patients who developed systemic relapse (3-year overall survival, 16.5% versus 15.3%; P = .089). Patients experiencing their first systemic relapse continued to have further systemic relapse, but only a minority progressed to iEMR, whereas those experiencing their iEMR at first relapse developed further systemic relapse and iEMR at approximately similar frequencies. A second iEMR was more common after a first iEMR than after a first systemic relapse (58.8% versus 13.0%; P = .001) and was associated with poor outcome. iEMR has a poor prognosis, particularly after a second relapse, and effective strategies are needed to improve outcomes.

Allogeneic hematopoietic stem cell transplantation in leukocyte adhesion deficiency type I and III.

Type I and III leukocyte adhesion deficiencies (LADs) are primary immunodeficiency disorders resulting in early death due to infections and additional bleeding tendency in LAD-III. The curative treatment of LAD-I and LAD-III is allogeneic hematopoietic stem cell transplantation (allo-HSCT). In this retrospective multicenter study, data were collected using the European Society for Blood and Marrow Transplantation registry; we analyzed data from 84 LAD patients from 33 centers, all receiving an allo-HSCT from 2007 to 2017. The 3-year overall survival estimate (95% confidence interval [CI]) was 83% (74-92) for the entire cohort: 84% (75-94) and 75% (50-100) for LAD-I and LAD-III, respectively. We observed cumulative incidences (95% CI) of graft failure (GF) at 3 years of 17% (9%-26%) and grade II to IV acute graft-versus-host disease (aGVHD) at 100 days of 24% (15%-34%). The estimate (95% CI) at 3 years for GF- and GVHD-II to IV-free survival as event-free survival (EFS) was 56% (46-69) for the entire cohort; 58% (46-72) and 56% (23-88) for LAD-I and LAD-III, respectively. Grade II to IV acute GVHD was a relevant risk factor for death (hazard ratio 3.6; 95% CI 1.4-9.1; P = .006). Patients' age at transplant ≥13 months, transplantation from a nonsibling donor, and any serological cytomegalovirus mismatch in donor-recipient pairs were significantly associated with severe acute GVHD and inferior EFS. The choice of busulfan- or treosulfan-based conditioning, type of GVHD prophylaxis, and serotherapy did not impact overall survival, EFS, or aGVHD. An intrinsic inflammatory component of LAD may contribute to inflammatory complications during allo-HSCT, thus providing the rationale for considering anti-inflammatory therapy pretreatment.

Prognostic factors for survival in children who relapsed after allogeneic hematopoietic stem cell transplantation for acute leukemia.

BACKGROUND: Post-transplant relapse has a dismal prognosis in children with acute leukemia undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT). Data on risk factors, treatment options, and outcomes are limited. PROCEDURE: In this retrospective multicenter study in which a questionnaire was sent to all pediatric transplant centers reporting relapse after allo-HSCT for a cohort of 938 children with acute leukemia, we analyzed 255 children with relapse of acute leukemia after their first allo-HSCT. RESULTS: The median interval from transplantation to relapse was 180 days, and the median follow-up from relapse to the last follow-up was 1844 days. The 3-year overall survival (OS) rate was 12.0%. The main cause of death was disease progression or subsequent relapse (82.6%). The majority of children received salvage treatment with curative intent without a second HSCT (67.8%), 22.0% of children underwent a second allo-HSCT, and 10.2% received palliative therapy. Isolated extramedullary relapse (hazard ratio (HR): 0.607, P = .011) and relapse earlier than 365 days post-transplantation (HR: 2.101, P < .001 for 0-180 days; HR: 1.522, P = .041 for 181-365 days) were found in multivariate analysis to be significant prognostic factors for outcome. The type of salvage therapy in chemosensitive relapse was identified as a significant prognostic factor for OS. CONCLUSION: A salvage approach with curative intent may be considered for patients with post-transplant relapse, even if they relapse in the first year post-transplantation. For sustainable remission, a second allo-HSCT may be recommended for patients who achieve complete remission after reinduction treatment.

Role of a second transplantation for children with acute leukemia following posttransplantation relapse: a study by the Turkish Bone Marrow Transplantation Study Group.

We examined outcomes of 51 pediatric patients with relapsed acute leukemia (AL) who underwent a second allogeneic hematopoietic stem cell transplantation (alloHSCT). After a median follow-up of 941 days (range, 69-2842 days), leukemia-free survival (LFS) and overall survival (OS) at 3 years were 26.6% and 25.6%, respectively. The nonrelapse mortality rate (NMR) and cumulative incidence of relapse (CIR) were 36.4% and 42.4%, respectively. The Cox regression analysis demonstrated that the risk factors at second transplantation for predicting limited LFS were active disease (hazard ratio (HR) = 5.1), reduced intensity conditioning (RIC) (HR = 5.0), matched unrelated donor (MUD) (HR = 3.4) and performance score <80 (HR = 3.2). Pediatric patients with AL who relapsed after their first alloHSCT may survive with a second alloHSCT. Disease status, conditioning intensity, donor type, and performance score at the second transplantation are the relevant risk factors. A score based on these factors may predict the results of the second transplantation.

Homozygous c.130-131 ins A (pW44X) mutation in the HAX1 gene as the most common cause of congenital neutropenia in Turkey: Report from the Turkish Severe Congenital Neutropenia Registry.

BACKGROUND: Severe congenital neutropenia is a rare disease, and autosomal dominantly inherited ELANE mutation is the most frequently observed genetic defect in the registries from North America and Western Europe. However, in eastern countries where consanguineous marriages are common, autosomal recessive forms might be more frequent. METHOD: Two hundred and sixteen patients with severe congenital neutropenia from 28 different pediatric centers in Turkey were registered. RESULTS: The most frequently observed mutation was HAX1 mutation (n = 78, 36.1%). A heterozygous ELANE mutation was detected in 29 patients (13.4%) in our cohort. Biallelic mutations of G6PC3 (n = 9, 4.3%), CSF3R (n = 6, 2.9%), and JAGN1 (n = 2, 1%) were also observed. Granulocyte colony-stimulating factor treatment was given to 174 patients (80.6%). Two patients died with infectious complications, and five patients developed myelodysplastic syndrome/acute myeloblastic leukemia. The mean (± mean standard error) follow-up period was 129.7 ± 76.3 months, and overall survival was 96.8% (CI, 94.4-99.1%) at the age of 15 years. In Turkey, severe congenital neutropenia mostly resulted from the p W44X mutation in the HAX1 gene. CONCLUSION: In Turkey, mutation analysis should be started with HAX1, and if this is negative, ELANE and G6PC3 should be checked. Because of the very high percentage of consanguineous marriage, rare mutations should be tested in patients with a negative mutation screen.

Total-body irradiation using linac-based volumetric modulated arc therapy: Its clinical accuracy, feasibility and reliability.

PURPOSE: To report the feasibility, accuracy, and reliability of volumetric modulated arc therapy (VMAT)-based total-body irradiation (TBI) treatment in patients with acute myeloid leukemia (AML) or acute lymphoblastic leukemia (ALL). MATERIALS AND METHODS: From 2015 to 2018, 30 patients with AML or ALL were planned and treated with VMAT-based TBI, which consisted of three isocenters and three overlapping arcs. TBI dose was prescribed to 90% of the planning treatment volume (PTV) receiving 12 Gy in six fractions, at two fractions per day. Mean lung and kidney doses were restricted less than 10 Gy, and maximum lens dose less than 6 Gy. Quality assurance (QA) comprised the verification of the irradiation plans via dose-volume histogram (DVH) based 3D patient QA system. RESULTS: Average mean lung dose was 9.7 ±â€¯0.2 Gy, mean kidney dose 9.6 ±â€¯0.2 Gy, maximum lens dose 4.5 ±â€¯0.4 Gy, mean PTV dose 12.7 ±â€¯0.1 Gy, and heterogeneity index of PTV was 1.16 ±â€¯0.02 in all patients. Grade 3 or more acute radiation toxicity was not observed. When comparing plan and DVH-based 3D patient QA results, average differences of 3.3% ±â€¯1.3 in mean kidney doses, 1.1% ±â€¯0.7 in mean lung doses, and 0.9% ±â€¯0.4 in mean target doses were observed. CONCLUSION: Linac-based VMAT increased the dose homogeneity of TBI treatment more than extended SSD techniques. Partial cone-beam CT and optical surface-guided system assure patient positioning. DVH-based 3D patient dose verification QA was possible with linac-based VMAT showing small differences between planned and delivered doses. It is feasible, accurate, and reliable.

Congenital Factor Deficiencies in Children: A Report of a Single-Center Experience.

Congenital factor deficiencies (CFDs) refer to inherited deficiency of coagulation factors in the blood. A total of 481 patients with CFDs, who were diagnosed and followed at our Pediatric Hematology and Oncology Clinic between 1990 and 2015, were retrospectively evaluated. Of the 481 cases, 134 (27.8%) were hemophilia A, 38 (7.9%) were hemophilia B, 57 (11.8%) were von Willebrand disease (vWD), and 252 (52.3%) were rare bleeding disorders (RBDs). The median age of the patients at the time of diagnosis and at the time of the study was 4.1 years (range: 2 months to 20.4 years) and 13.4 years (range: 7 months to 31.3 years), respectively. The median duration of the follow-up time was 6.8 years (range: 2.5 months to 24.8 years). One hundred nineteen (47.2%) of 252 patients with RBDs were asymptomatic, 49 (41.1%) of whom diagnosed by family histories, 65 (54.6%) through preoperative laboratory studies, and 5 (4.2%) after prolonged bleeding during surgeries. Consanguinity rate for the RBDs was 47.2%. Prophylactic treatment was initiated in 80 patients, 58 of whom were hemophilia A, 7 were hemophilia B, 13 were RBDs, and 2 were vWD. Significant advances have been achieved during the past 2 decades in the treatment of patients with CFDs, particularly in patients with hemophilias. The rarity and clinical heterogeneity of RBDs lead to significant diagnostic challenges and improper management. In this regard, multinational collaborative efforts are needed with the hope that can improve the management of patients with RBDs.

Hematopoietic stem cell transplantation in children with Griscelli syndrome: A single-center experience.

GS2 is a rare autosomal recessive disease characterized by hypopigmentation, variable immunodeficiency with HLH. HSCT is the only curative treatment for GS2. We analyzed the outcome of 10 children with GS2 who underwent HSCT at our center between October 1997 and September 2013. The median age of the patients at transplant was 13.5 months (range, 6-58 months). All of the patients developed HLH before HSCT and received HLH 94 or HLH 2004 protocols. Donors were HLA-identical relatives in 8 patients, HLA-mismatched relatives in 2 patients. Engraftment was achieved in all except one patient. None of the patients developed acute GVHD. Chronic GVHD occurred in one and veno-occlusive disease occurred in four patients. Eight of the patients are under remission without any neurologic sequelae-median time of disease-free survival is 92.4 months. The present study shows successful transplant outcome without long-term neurologic sequelae in patients with GS2 who underwent HSCT from HLA-related donors.

Treatment of neonatal fungal infective endocarditis with recombinant tissue plasminogen: activator in a low birth weight infant case report and review of the literature.

With advances in medical sciences, an increase in survival rates of low birth weight; increased incidence in use of catheter and antibiotics, and total parenteral nutrition are reported, therefore, the rate of fungal infections in late and very late onset neonatal sepsis have increased. Although fungal endocarditis rarely occur in newborns, it has a high morbidity and mortality. Antifungal therapy is often insufficient in cases who develop fungal endocarditis and surgical treatment is not preferred due to its difficulty and high mortality. Herein, fungal endocarditis in a preterm newborn treated with single-dose recombinant tissue plasminogen activator in addition to antifungal therapy is presented and relevant literature has been reviewed. The vegetation completely disappeared following treatment and no complication was observed.

Acute Megakaryoblastic Leukemia with t(1;22) Mimicking Neuroblastoma in an Infant.

Acute megakaryoblastic leukemia (AMKL) with t(1;22) (p13;q13) is an extremely rare subtype of acute myeloid leukemia that is almost always described in infants. t(1;22) (p13;q13)-positive AMKL with extramedullary infiltration has been previously reported only once in the literature. Herein, we report a 3-month-old infant presenting with a pelvic mass and pancytopenia suggesting neuroblastoma. Bone marrow evaluation revealed t(1;22)-positive AMKL that responded well to a regimen containing high-dose cytarabine.

Coexisting or underlying risk factors of hepatic veno-occlusive disease in pediatric hematopoietic stem cell transplant recipients receiving prophylaxis.

OBJECTIVES: To evaluate the characteristics of veno-occlusive disease in pediatric hematopoietic stem cell transplant recipients, and their effect as a prophylactic regimen on severity and outcome. MATERIALS AND METHODS: This study included 204 allogeneic hematopoietic stem cell transplants performed on 187 children whose data retrospectively described the risk factors, prophylaxis, and treatment modalities of veno-occlusive disease. A prophylactic regimen composed of enoxaparin versus ursodeoxycholic acid and vitamin E was given to 167 of 204 patients. RESULTS: Veno-occlusive disease developed in 22 patients (10.8%). Nineteen patients experienced veno-occlusive disease despite this prophylactic regimen. The prophylaxis seemed ineffective in preventing veno-occlusive disease (P = .657). Regarding risk factors, oral busulphan use, liposomal amphotericin B vancomycin treatment, and total parenteral nutrition were associated with an increased risk of veno-occlusive disease. Conversely, renal impairment also was associated with increased mortality in patients with veno-occlusive disease. The mortality rate in the first 100 days after a hematopoietic stem cell transplant was higher in the patients with veno-occlusive disease than it was in those without the disease. CONCLUSIONS: Our prophylactic regimen may have played a role in the fairly low incidence of veno-occlusive disease in a pediatric population with high-risk features.

Anaphylactic reaction to polyethylene-glycol conjugated-asparaginase: premedication and desensitization may not be sufficient.

In hypersensitive reactions to native L-asparaginase, either premedication and desensitization or substitution with polyethylene glycol conjugated asparaginase (PEG-ASP) is preferred. Anaphylaxis with PEG-ASP is rare. An 8-year-old girl and a 2.5-year-old boy, both diagnosed as having acute lymphoblastic leukemia, presented with native L-asparaginase hypersensitivity and substitution with PEG-ASP was preferred. They received a premedication (methylprednisolone, hydroxyzine and ranitidine) followed by desensitization with PEG-ASP infusion. Both patients developed anaphylaxis with peg-asparaginase. These are the first reported cases of anaphylactic reaction to PEG-ASP, despite the application of both premedication and desensitization. Anaphylaxis with PEG-ASP is very rare and premedication and desensitization protocols may not prevent these hypersensitive reactions.

Molecular diagnosis of shwachman-diamond syndrome presenting with pancytopenia at an early age: the first report from Turkey.

A three-month-old boy presented with growth failure, skeletal abnormalities, otitis media and pancytopenia. Exocrine pancreatic insufficiency was confirmed by low levels of fecal elastase. He was diagnosed as Shwachman-Diamond syndrome by clinical and laboratory findings. The diagnosis was confirmed by sequence analysis for SBDS gene on chromosome seven revealing compound heterozygous mutation, which are c.258+2T-C and c.183-184TA-CT. Matched unrelated donor screening for hematopoietic stem cell transplantation was initiated. Unfortunately, he died of respiratory difficulty at 5 months of age. Our case is the youngest patient whose presumptive Shwachman-Diamond syndrome diagnosis was confirmed by molecular analysis.

Recurrent pediatric thrombosis: the effect of underlying and/or coexisting factors.

The objective of this study was to evaluate the underlying diseases, thrombus localization, and other risk factors in pediatric patients with recurrent thrombosis in order to obtain a sense of early awareness of the possible recurrences. We retrospectively evaluated both inherited and acquired thrombophilic risk factors in children with recurrent thrombosis that were diagnosed and treated at Hacettepe University, School of Medicine, Department of Pediatric Hematology, Ankara, Turkey. Both congenital and acquired risk factors associated with recurrent thrombosis, and treatment modalities were analyzed in detail. Among 569 children with thrombosis, 32 (5.6%) presented with recurrent thrombosis. Median age at first presentation in these 32 patients [11 women (34.4%) and 21 men (65.6%)] was 132 months. In all, 29 (90.6%) of the 32 patients had an underlying chronic disorder: the most common of which was congenital heart disease [n = 11 (34.4%)]. At presentation intracardiac localization, including the entrance of the inferior and superior vena cava, was observed in 10 of the patients (31.2%). Thrombosis recurred at the same location in 15 (47%) patients and at a different location in 17 (53%). Median time interval between the first and second episode of thrombosis was 6.5 months (range: 1-180 months). Considering both acquired and congenital thrombophilic factors, three (9.3%) patients, four (12.5%) patients, and 14 (43.8%) patients had five, four, and three risk factors, respectively. More than half of the patients had elevated plasma FVIII (>150 IU/dl) and D-dimer (>0.5 mg/ml) levels. Thrombectomy was performed in three patients with organized, chronic intracardiac thrombus. Tissue plasminogen activator (t-PA) was used more frequently to treat recurrence than the first event (15.6 vs. 28.1%) and consequently the complete resolution rate was higher (40 vs. 77.7%) at the second event. Thrombi partially resolved in 11 of the patients during the initial episode and in 10 patients during recurrence (34 vs. 32%). In all, 29 (87.5%) patients were using prophylaxis at the time of recurrence. [coumadin (n = 16), low molecular weight heparin (n = 12) and aspirin (n = 1)]. In total, four patients (12.5%) died because of their underlying disorders and six (18.7%) developed postthrombotic syndrome during the follow-up. Recurrent thrombosis should be expected, especially in cases with congenital heart disease, incomplete thrombus resolution, and elevated plasma FVIII/D-dimer levels. In the light of this knowledge we suggest aggressive treatment for pediatric patients with a high risk of recurrent thrombosis.