Identification of the molecular etiology in rare congenital hemolytic anemias using next-generation sequencing with exome-based copy number variant analysis.

OBJECTIVES: In congenital hemolytic anemias (CHA), it is not always possible to determine the specific diagnosis by evaluating clinical findings and conventional laboratory tests. The aim of this study is to evaluate the utility of next-generation sequencing (NGS) and clinical-exome-based copy number variant (CNV) analysis in patients with CHA. METHODS: One hundred and forty-three CHA cases from 115 unrelated families referred for molecular analysis were enrolled in the study. Molecular analysis was performed using two different clinical exome panels in 130 patients, and whole-exome sequencing in nine patients. Exome-based CNV calling was incorporated into the traditional single-nucleotide variant and small insertion/deletion analysis pipeline for NGS data in 92 cases. In four patients from the same family, the PK Gypsy variant was investigated using long-range polymerase chain reaction. RESULTS: Molecular diagnosis was established in 86% of the study group. The most frequently mutated genes were SPTB (31.7%) and PKLR (28.5%). CNV analysis of 92 cases revealed that three patients had different sizes of large deletions in the SPTB and six patients had a deletion in the PKLR. CONCLUSIONS: In this study, NGS provided a high molecular diagnostic rate in cases with rare CHA. Analysis of the CNVs contributed to the diagnostic success.

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.

Clinical features and risk factors of hepatic sinusoidal obstruction syndrome in children after hematopoietic stem cell transplantation: A single-center experience.

Hepatic sinusoidal obstruction syndrome (SOS) is an illness with serious life effects that develops after hematopoietic stem cell transplantation (HSCT). We investigated the risk factors and clinical features of hepatic SOS in children following HSCT in 210 children who underwent allogeneic or autologous HSCT between 2009 and 2021 were analyzed in the context of SOS. The syndrome developed in 22 (10.4%) patients:frequently in neuroblastoma [24% (5/21)], hemophagocytic lymphohistiocytosis [57% (4/7)], and thalassemia major [22% (7/31)]. The median time from HSCT to diagnosis was 16 (6-38) days. Severe disease occurred in 8 (36%) patients, and mild/moderate in 14 (64%) and 4 patients died (18%). In univariate analyses, patient's age ≤ 2 years [odds ratio (OR)= 3.043, P = 0.028], pretransplant AST and ALT levels > 100 U/L (OR=3.576, P = 0.045), and chemotherapy/radiotherapy to abdomen before transplantation (OR = 3.162, P = 0.044) were determined as risk factors. In multivariate analysis, pre-transplant AST and ALT levels > 100 U/L (OR = 16.04, P = 0.010) and ferritin levels over 1000 mg/dl (OR=5.15, P = 0.047) were significant. The only independent risk factor on mortality was the age ≤ 2 years (P = 0.001). Although our study confirmed several risk factors for SOS, we failed to achieve some well-known risk factors. Precautions should be taken considering the factors affecting liver function before transplantation and the risk of SOS in infants receiving chemotherapy and radiotherapy before transplantation, such as neuroblastoma in which comparable results in respect to the chemotherapy only. The risk factors should be fully elucidated in multicenter studies to improve preventive and therapeutic strategies.

Central Nervous System Fungal Infections in Children With Leukemia and Undergoing Hematopoietic Stem Cell Transplantation: A Retrospective Multicenter Study.

BACKGROUND: Central nervous system fungal infections (CNSFI) are seen in patients with hematologic malignancies and have high morbidity and mortality. Because of their rarity, there is limited data on CNSFI in children with no established treatment protocols or guidelines. MATERIALS AND METHODS: In this multicenter retrospective study, 51 pediatric patients with leukemia, 6 of whom had undergone bone marrow transplantation, with proven or probable CNSFI were evaluated. Fungal infections were defined as proven or probable based on European Organisation for Research and Treatment of Cancer criteria. Proven CNSFI was diagnosed by appropriate central nervous system (CNS) imaging or tissue sample findings in combination with positive microbiological results of cerebrospinal fluid. A positive culture, microscopic evidence of hyphae, a positive result of the galactomannan assays are defined as positive microbiological evidence. Probable CNSFI was defined as appropriate CNS imaging findings together with proven or probable invasive fungal infections at another focus without CNS when there is no other explanatory condition. Data was collected by using the questionnaire form (Supplemental Digital Content 1, http://links.lww.com/JPHO/A541 ). RESULTS: Seventeen patients had proven, 34 patients had probable CNSFI. Headaches and seizures were the most common clinical findings. The median time between the onset of fever and diagnosis was 5 days. The most common fungal agent identified was Aspergillus . Sixteen patients received single-agent, 35 received combination antifungal therapy. Surgery was performed in 23 patients. Twenty-two patients (43%) died, 29 of the CNSFI episodes recovered with a 20% neurological sequelae. CONCLUSION: CNSFIs should be considered in the differential diagnosis in patients with leukemia and refractory/recurrent fever, headache, neurologicalocular symptoms, and a radiologic-serological evaluation should be performed immediately. Early diagnosis and prompt management, both medical and surgical, are essential for improving clinical outcomes.

Results of multicenter registry for patients with inherited factor VII deficiency in Turkey.

INTRODUCTION: Inherited factor VII (FVII) deficiency (FVIID) is the most common of inherited rare bleeding disorders. Other determinants of clinical severity apart from FVII level (FVIIL) include genetic and environmental factors. We aimed to identify the cut-off FVIILs for general and severe bleedings in patients with FVIID by using an online national registry system including clinical, laboratory, and demographic characteristics of patients. METHODS: Demographic, clinical, and laboratory data of patients with FVIID extracted from the national database, constituted by the Turkish Society of Hematology, were examined. Bleeding phenotypes, general characteristics, and laboratory features were assessed in terms of FVIILs. Bleeding rates and prophylaxis during special procedures/interventions were also recorded. RESULTS: Data from 197 patients showed that 46.2% of patients had FVIIL< 10%. Most bleeds were of mucosal origin (67.7%), and severe bleeds tended to occur in younger patients (median age: 15 (IQR:6-29)). Cut-off FVIILs for all and severe bleeds were 16.5% and 7.5%, respectively. The major reason for long-term prophylaxis was observed as central nervous system bleeding (80%). CONCLUSION: Our data are consistent with most of the published literature in terms of cut-off FVIIL for bleeding, as well as reasons for prophylaxis, showing both an increased severity of bleeding and younger age at diagnosis with decreasing FVIIL. However, in order to offer a classification similar to that in Hemophilia A or B, data of a larger cohort with information about environmental and genetic factors are required.

Flow cytometric analysis of platelet surface glycoproteins in the diagnosis of thirty-two Turkish patients with Glanzmann thrombasthenia: a multicenter experience

Background/aim: Glanzmann thrombasthenia (GT) is a rare autosomal recessively inherited bleeding disorder characterized by the quantitative (type 1 and type 2) or qualitative (type 3) deficiency in platelet membrane glycoprotein (GP) IIb/IIIa (CD41a/CD61) fibrinogen receptors. In type 1, 2, and 3, CD41a/CD61 expression is 5%, 5%­20% and above 20%, respectively. In this study, diagnosis of GT was confirmed and subgroups were identified in 32 Turkish patients by flow cytometry analysis. Materials and methods: CD41a/CD61 expression levels in platelet-rich plasma (PRP) obtained from peripheral venous EDTA blood samples were analyzed with a BD FACSCanto II flow cytometer (Becton Dickinson, Franklin Lakes, NJ, USA). GT subgroup analysis was performed by counting 50,000 events in the BD FACSDiva Software v6.1.3 program of the instrument. Results: In the present study, in blood samples of 32 patients from 23 families with GT and 22 healthy controls, co-expression levels of CD41a and CD61 in PRP was analyzed. 12 out of 23 families were consistent with type 1 GT (52.2%), 4 were consistent with type 2 GT (17.4%), and 7 were consistent with type 3 GT (30.4%). Conclusion: Especially due to consanguineous marriages, GT with various glycoprotein levels may be detected. As a result of the flow cytometry analysis of the present study with the highest GT patient population in Turkey, type 1 GT patients were the most common subgroup. In the determination of the GT subgroups; especially in the detection of type 3 GT, flow cytometry is the most sensitive glycoprotein analysis method. In addition to light transmission aggregometry, CD41a/CD61 study by flow cytometer confirms diagnosis when mutation analysis cannot be performed.

Once-weekly prophylaxis with glycoPEGylated recombinant factor VIII (N8-GP) in severe haemophilia A: Safety and efficacy results from pathfinder 2 (randomized phase III trial).

INTRODUCTION: Turoctocog alfa pegol (N8-GP) is a site-specific, 40 kDa glycoPEGylated recombinant factor VIII (FVIII) product with an extended half-life. The comprehensive main phase of the pivotal pathfinder 2 trial showed N8-GP dosed every 4 days (Q4D) provided favourable safety and efficacy for preventing bleeds in 175 patients with haemophilia A. AIM AND METHODS: We investigated the safety and efficacy of N8-GP prophylaxis when administered weekly (Q7D) for 24 weeks to patients with low bleeding rates in the pathfinder 2 extension trial. Patients (≥12 years) with ≤2 bleeds during the preceding 6 months of the pathfinder 2 main phase were eligible for randomization to receive N8-GP 50 IU/kg Q4D or 75 IU/kg Q7D. Safety and efficacy endpoints were incidence of FVIII inhibitors and annualized bleeding rate (ABR), respectively. RESULTS: Fifty-five of 143 (38.5%) patients on prophylaxis who continued into the extension phase were randomized to receive 50 IU/kg Q4D (n = 17) or 75 IU/kg Q7D (n = 38). Nine patients in the Q7D cohort reverted to 50 IU/kg Q4D. No inhibitors were detected. In both cohorts, >50% of patients experienced no bleeds. Median ABR for overall, joint, spontaneous, traumatic and muscle was 0.00 for both cohorts. Overall estimated success rate for treating bleeding episodes was 87.5%; 94.7% of bleeds were controlled with ≤2 injections. CONCLUSIONS: Weekly N8-GP was well tolerated and efficacious and may benefit selected "low bleeder" patients with haemophilia A.

The role of hepcidin, GDF15, and mitoferrin-1 in iron metabolism of polycythemia vera and essential thrombocytosis patients

Background/aim: GDF15, hepcidin and mitoferrin-1 (mfrn-1) are proteins involved in systemic iron regulation. There are no studies in the literature demonstrating the serum mfrn-1 levels in polycythemia vera (PV) and essential thrombocythemia (ET) patients. The aim of this study was to investigate GDF15, hepcidin and mfrn-1 levels in PV and ET patients. Materials and methods: Ten PV, 17 ET patients, and 27 healthy controls (HCs) were enrolled. GDF15, hepcidin and mfrn-1 values were measured with enzyme-linked immunosorbent assay (ELISA). Results: GDF15 levels were higher in the myeloproliferative neoplasm (MPN) group (P = 0.002). Hepcidin levels were not different between MPN patients and HCs. The mfrn-1 levels were lower in MPN patients (P = 0.039). Hepcidin, GDF15, and mfrn-1 levels were not different between PV and ET patients. mfrn-1 levels were lower in ET patients than HCs (P = 0.038). Conclusion: Increased erythropoiesis in MPNs may lead to high GDF15 levels in these patients. However, hepcidin was not suppressed despite the increased GDF15 levels and erythropoiesis in these patients. Decrease in mfrn-1 in MPNs can be the result of its increased turnover due to increased myelopoiesis. It can be hypothesized that similar hepcidin levels in patients and controls and low mfrn-1 levels in patients may be a defense mechanism against erythroid activity and thromboembolic complications.

Autosomal recessive osteopetrosis with a unique imaging finding: multiple encephaloceles.

Osteopetrosis is a hereditary form of sclerosing bone dysplasia with various radiological and clinical presentations. The autosomal recessive type, also known as malignant osteopetrosis, is the most severe type, with the early onset of manifestations. A 5-month-old infant was admitted to our hospital with recurrent respiratory tract infections. Chest X-ray and skeletal survey revealed the classic findings of osteopetrosis, including diffuse osteosclerosis and bone within a bone appearance. At follow-up, the patient presented with, thickened calvarium, multiple prominent encephaloceles, and dural calcifications leading to the intracranial clinical manifestations with bilateral hearing and sight loss. Autosomal recessive osteopetrosis is one of the causes of encephaloceles and this finding may become dramatic if untreated.

Marked overlap of four genetic syndromes with dyskeratosis congenita confounds clinical diagnosis.

Dyskeratosis congenita is a highly pleotropic genetic disorder. This heterogeneity can lead to difficulties in making an accurate diagnosis and delays in appropriate management. The aim of this study was to determine the underlying genetic basis in patients presenting with features of dyskeratosis congenita and who were negative for mutations in the classical dyskeratosis congenita genes. By whole exome and targeted sequencing, we identified biallelic variants in genes that are not associated with dyskeratosis congenita in 17 individuals from 12 families. Specifically, these were homozygous variants in USB1 (8 families), homozygous missense variants in GRHL2 (2 families) and identical compound heterozygous variants in LIG4 (2 families). All patients had multiple somatic features of dyskeratosis congenita but not the characteristic short telomeres. Our case series shows that biallelic variants in USB1, LIG4 and GRHL2, the genes mutated in poikiloderma with neutropenia, LIG4/Dubowitz syndrome and the recently recognized ectodermal dysplasia/short stature syndrome, respectively, cause features that overlap with dyskeratosis congenita. Strikingly, these genes also overlap in their biological function with the known dyskeratosis congenita genes that are implicated in telomere maintenance and DNA repair pathways. Collectively, these observations demonstrate the marked overlap of dyskeratosis congenita with four other genetic syndromes, confounding accurate diagnosis and subsequent management. This has important implications for establishing a genetic diagnosis when a new patient presents in the clinic. Patients with clinical features of dyskeratosis congenita need to have genetic analysis of USB1, LIG4 and GRHL2 in addition to the classical dyskeratosis congenita genes and telomere length measurements.

Invasive fungal infections in children with hematologic and malignant diseases.

BACKGROUND: To evaluate the clinical feature and outcome of invasive fungal infections (IFI) in children with hematologic and malign diseases. PATIENTS AND METHODS: The medical records of children with hematologic and malignant diseases, who were hospitalized at our hospital between January 2010 and December 2011, were reviewed. Proven, probable, and possible IFIs were diagnosed according to the revised definitions of the European Organization for Research and Treatment of Cancer/Mycosis Study Group. The demographic, clinical, and laboratory characteristics of the patients who met the study criteria were evaluated. RESULTS: IFI was diagnosed in 67 (7.2%) febrile episodes of 56 patients, of which 10 (1.2%) were proven, 20 (2%) probable, and 37 (4%) possible IFI. Blood culture of 10 cases with proven IFI yielded yeast and the most common isolated agent was Candida parapsilosis. Seventy percent of cases with fungemia had central venous catheter (CVC). Twenty cases with probable IFI had invasive mold infection. The cases with mold infection had higher median C-reactive protein values, lower neutrophil counts, and longer duration of neutropenia compared with the cases with yeast infection. A total of 14 patients (20.9%) died. Presence of CVC, bone marrow transplantation, total parenteral nutrition, prolonged fever, and proven/probable IFI were detected more often in patients who died, compared with patients who survived. CONCLUSIONS: IFIs are important causes of death in children with hematologic and malignant diseases. Mold infections are seen more frequently in cases with prolonged and profound neutropenia, and invasive yeast infections, especially with non-albicans Candida species, in cases with CVC. Early and effective treatment considering these findings will help to decrease the mortality.

Red cell glucose 6-phosphate dehydrogenase deficiency in the northern region of Turkey: is G6PD deficiency exclusively a male disease?

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an X-linked recessive genetic defect that can cause hemolytic crisis. However, this disease affects both males and females. In Turkey, the frequency of this enzyme deficiency was reported to vary, from 0.25 to 18%, by the geographical area. Its prevalence in the northern Black Sea region of Turkey is unknown. The aims of this study were to assess the prevalence of G6PD deficiency in the northern region Turkey in children and adults with hyperbilirubinemia and hemolytic anemia. This report included a total of 976 G6PD enzyme results that were analyzed between May 2005 and January 2014. G6PD deficiency was detected in 5.0% of all patients. G6PD deficiency was significantly less frequent in females (1.9%, 6/323) than in males (6.6%, 43/653). G6PD deficiency was detected in 3.7% of infants with hyperbilirubinemia, 9.2% of children, and 4.5% of adults with hemolytic anemia. In both the newborn group and the group of children, G6PD deficiency was significantly more frequent in males. In the combined group of children (groups I and II), the proportion of males was 74% and 67% in all groups (P = .0008). In conclusion, in northern region of Turkey, G6PD deficiency is an important cause of neonatal hyperbilirubinemia and hemolytic crisis in children and adults. This study suggests that most pediatricians thought that G6PD deficiency is exclusively a male disease. For this reason, some female patients may have been undiagnosed.

Common viral respiratory infections in children with cancer during the COVID-19 pandemic: a multicenter study from Türkiye.

BACKGROUND: Microbiologic confirmation of respiratory tract infections gained importance during the coronavirus disease 2019 (COVID-19) pandemic. This study retrospectively evaluated seasonal distribution, clinical presentation, and complications of respiratory viral infections (RVIs) other than COVID-19 in children with cancer during and after the pandemic lockdown. METHODS: Two hundred and sixty-five inpatient and outpatient RVI episodes in 219 pediatric cancer patients confirmed by multiplex reverse transcriptase polymerase chain reaction (RT-PCR) panels from 13 centers were enrolled. RESULTS: Eighty-six (32.5%) of the total 265 episodes occurred in 16 months corresponding to the lockdowns in Türkiye, and the remaining 67.5% in 10 months thereafter. Human rhinovirus/enterovirus (hRE) (48.3%) was the most common agent detected during and after lockdown. Parainfluenza virus (PIV) (23.0%), influenza virus (9.8%), and respiratory syncytial virus (RSV) (9.1%) were the other common agents. The 28.7% of episodes were lower respiratory tract infections (LRTIs), and complications and mortality were higher than upper respiratory tract infections (URTIs) (25.0% vs 5.3%). Bacteremia was identified in 11.5% of culture-drawn episodes. Treatment delay in one-third and death within four weeks after RVI in 4.9% of episodes were observed. CONCLUSION: During the pandemic, fewer episodes of RVIs occurred during the lockdown period. Respiratory viruses may cause complications, delays in treatment, and even death in children with cancer. Therefore, increased awareness of RVIs and rapid detection of respiratory viruses will benefit the prevention and, in some cases, abrupt supportive and some antiviral treatment of RVI in children with cancer.

Frequency of obesity and metabolic syndrome in childhood leukemia and lymphoma survivors.

OBJECTIVES: In this study, it was aimed to determine the prevalence and clinical features of obesity and metabolic syndrome, which are long-term effects of survivors after treatment in children with leukemia and lymphoma. PATIENTS AND METHODS: Patients with leukemia and lymphoma, who were diagnosed between 2000 and 2012 (at least 2 two years after remission) were included. Data obtained through reviewing the family history, demographic characteristics, anthropometric measurements, and laboratory parameters (blood glucose, lipid, and insulin levels) were analyzed and compared at the time of diagnosis, after the treatment and at time of the study. RESULTS: Eighty nine patients (45 boys, 44 girls) were included (mean age: 14.7 ± 4.3 years): 77.5% had acute lymphoblastic leukemia, 11.2% had acute myeloid leukemia, and 11.2% had lymphoma. Overall, 46% patients had received radiotherapy, 7% had undergone surgery, and 2.2% had received stem cell transplantation in addition to chemotherapy. The mean duration of treatment was 2.4 years, and the time elapsed after treatment was 4.9 years. While only one had obesity at the diagnosis, a significant increase in obesity (20%), hypertension (15.7%), hyperglycemia (15%), insulin resistance (35%) were observed at the time of study, and family history of hypertension, dyslipidemia, and cardiovascular diseases were significantly higher in this subgroup. CONCLUSION: The prevalence of metabolic syndorme is higher in children with leukemia and lymphoma after treatment, and begins to increase with the initiation of treatment and continues to increase over time. These children should be followed-up for late-effects including metabolic syndrome through life-long period.

Clinical Characteristics and Outcomes of COVID-19 in Turkish Patients with Hematological Malignancies

Objective: Patients with solid malignancies are more vulnerable to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection than the healthy population. The outcome of SARS-CoV-2 infection in highly immunosuppressed populations, such as in patients with hematological malignancies, is a point of interest. We aimed to analyze the symptoms, complications, intensive care unit admissions, and mortality rates of patients with hematological malignancies infected with SARS-CoV-2 in Turkey. Materials and Methods: In this multicenter study, we included 340 adult and pediatric patients diagnosed with SARS-CoV-2 from March to November 2020. Diagnosis and status of primary disease, treatment schedules for hematological malignancies, time from last treatment, life expectancy related to the hematological disease, and comorbidities were recorded, together with data regarding symptoms, treatment, and outcome of SARS-CoV-2 infection. Results: Forty four patients were asymptomatic at diagnosis of SARS-CoV- 2 infection. Among symptomatic patients, fever, cough, and dyspnea were observed in 62.6%, 48.8%, and 41.8%, respectively. Sixty-nine (20%) patients had mild SARS-CoV-2 disease, whereas moderate, severe, and critical disease was reported in 101 (29%), 71 (20%), and 55 (16%) patients, respectively. Of the entire cohort, 251 (73.8%) patients were hospitalized for SARS-CoV-2. Mortality related to SARS-CoV-2 infection was 26.5% in the entire cohort; this comprised 4.4% of those patients with mild disease, 12.4% of those with moderate disease, and 83% of those with severe or critical disease. Active hematological disease, lower life expectancy related to primary hematological disease, neutropenia at diagnosis of SARS-CoV-2, ICU admission, and first-line therapy used for coronavirus disease-2019 treatment were found to be related to higher mortality rates. Treatments with hydroxychloroquine alone or in combination with azithromycin were associated with a higher rate of mortality in comparison to favipiravir use. Conclusion: Patients with hematological malignancy infected with SARS-CoV-2 have an increased risk of severe disease and mortality.

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.

Clinical follow-up of children with high vitamin B12 values: should we worry?

BACKGROUND: Requests of Vitamin B12 test increased with the widespread use of autoanalysers. Although the cause of requests was deficiency suspicions, an important ratio of high levels of Vitamin B12 were reported to physicians by laboratory. Ratios of values of high Vitamin B12 among test request in adults are reported as 14- 20% in present three monocentre studies and one multicentre study. There is no report on children with high vitamin B12 for both ratio in lab requests or clinical follow up. METHODS: We evaluated the records of 40 children (23 male /17 female) with high B12 values ( > 1000 pg/ ml) retrospectively. Children were otherwise healthy children and were seen at outpatient pediatric clinics. Additionally, vitamin B12 values of 13 acute lymphoblastic leukemia patients at diagnosis time were retrieved to enlighten possible role of lymphocytes. RESULT: Children did not have any malign or chronic diseases causing the high Vitamin B12 values. Holotranscobalamin levels were normal or slightly above. Two patients did develop leukemia later. Our follow up showed that high vitamin B12 values slightly decreased at 3 months and then remained unchanged later. The high numbers of T and B cells are not the source of vitamin B12 elevation. CONCLUSIONS: Our study suggests that high-vitamin B12 values are usually benign in children but some patients may develop leukemia later. We suggest that patients should be followed up for some time after testing for severe hematological diseases.

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.

Factor 8 Gene Mutation Spectrum of 270 Patients with Hemophilia A: Identification of 36 Novel Mutations

Objective: Hemophilia A (HA) is the most severe X-linked inherited bleeding disorder caused by hemizygous mutations in the factor 8 (F8) gene. The aim of this study is to determine the mutation spectrum of the F8 gene in a large HA cohort from Turkey, and then to establish a phenotype-genotype correlation. Materials and Methods: All HA cases (270 patients) analyzed molecularly in the Ege University Pediatric Genetics Molecular Laboratory between March 2017 and March 2018 were included in this study. To identify intron 22 inversion (Inv22), intron 1 inversion (Inv1), small deletion/insertions, and point mutations, molecular analyses of F8 were performed using a sequential application of molecular techniques. Results: The mutation detection success rate was 95.2%. Positive Inv22 was found in 106 patients (39.3%), Inv1 was found in 4 patients (1.5%), and 106 different disease-causing sequence variants were identified in 137 patients (50.6%). In 10 patients (3.7%), amplification failures involving one or more exonic regions, considered to be large intragenic deletions, were identified. Of 106 different F8 mutations, 36 were novel. The relationship between F8 genotype and inhibitor development was considered significant. Conclusion: A high mutation detection rate was achieved via the broad molecular techniques applied in this study, including 36 novel mutations. With regard to mutation types, mutation distribution and their impact on clinical severity and inhibitor development were found to be similar to those previously reported in other hemophilia population studies.

Hematological disturbances in Down syndrome: single centre experience of thirteen years and review of the literature.

Karakurt N, Uslu I, Aygün C, Albayrak C. Hematological disturbances in Down syndrome: single centre experience of thirteen years and review of the literature. Turk J Pediatr 2019; 61: 664-670. Neonates with Down syndrome (DS) may have hematological abnormalities such as polycythemia, thrombocytopenia and transient leukemia (TL). The primary objective of this study was to report the descriptive data of complete blood counts (CBC) of neonates with DS, which were obtained within first week of life. We wanted to focus on neonates with hematological abnormalities and compare them among those with and without TL. The secondary objective was the description of hematological malignancies in the first six years of life. Medical records of 100 neonates with DS between 2006-2018 were assessed. Hematological abnormalities were present in 73/100. We detected anemia in 16, polycythemia in eight, microcytosis in 10, leukopenia in two, leukocytosis in 11, thrombocytopenia in 26, thrombocytosis in 7 and TL in 11 patients. TL group had higher levels of leukocyte count (115.0±93.0x103/mm3) when compared with neonates without TL (11.7±5.6x103/mm3) (p < 0.001). No other statistically significant difference between groups for hemoglobin, MCV and platelet count levels was detected. In the follow- up period, two patients developed acute lymphoblastic leukemia, one hemophagocytic lymphohistiocytosis and one Burkitt lymphoma. None of the TL survivors developed myeloid leukemia of Down Syndrome (ML-DS). Thrombocytopenia may be detected frequently in DS and it may not be a part of TL. We suggest that CBC with peripheral blood film should be evaluated for every patient to check for TL and other hematological disturbances. Despite the fact that none of our TL survivors developed overt leukemia (ML-DS), we also suggest that patients with DS be followed due to the risk of developing leukemia.