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.

Monitoring of adenoviremia in pediatric patients undergoing hematopoietic stem cell transplantation: Is it alone sufficient to predict adenoviral disease?

BACKGROUND: We aimed to evaluate our pediatric HSCT recipients routinely monitored for adenoviremia and to determine the adequacy of this monitoring in predicting adenoviral disease (AD). METHODS: A retrospective cohort of patients who underwent allogeneic HSCT between January 2021 and August 2022, and routinely monitored for adenoviremia by real-time PCR was included in our survey. Demographic and clinical data of the patients were recorded. Incidence rates, risk factors, and mortality rates related to adenoviremia, and AD were analyzed. RESULTS: Among 104 HSCTs performed in 94 patients adenovirus (AdV) was revealed in 27 (26%) episodes and adenoviremia in 18 (17.3%) HSCT episodes. AD without adenoviremia developed in nine episodes (8.6%). Disseminated disease was significantly more frequently detected in episodes with adenoviremia (p = .008). GVHD was independent risk factor for AdV detection (OR: 8.6, 95% CI: 2.03-33.7, p = .001). Viremia developed within a shorter time interval after HSCT in isolated episodes of adenoviremia compared to those with concomitant AD (p = .006). Initial and peak viral loads were significantly higher in adenoviremia with AD (p < .001). Mortality was higher in the AdV-detected episodes (p < .001) than in the AdV-undetected episodes. AdV-related mortality was found to be 22.2%. Adenoviremia increased the risk of mortality (OR: 1.2, 95% CI: 0.22-1.33, p = .01). CONCLUSIONS: Adenoviremia monitoring is an important process in the detection of AD. Since some patients may develop AD without accompanying by adenoviremia, monitoring for AdV in blood samples should be supported with other monitoring methods in order to evaluate the probable involvement of different organs or systems.

Characteristics and management of hypersensitivity reactions with rabbit anti-thymocyte globulin in pediatric patients.

Background: Anti-thymocyte globulin (ATG) has been successfully used for decades to prevent graft versus host disease before hematopoietic stem cell transplantation (HSCT) as a part of conditioning regimen. However, sometimes hypersensitivity reactions may limit its use. Objective: To evaluate hypersensitivity reactions experienced during rabbit-ATG infusion among children and present successful desensitization protocol. Methods: The medical records of pediatric patients who were given rabbit-ATG treatment at our tertiary center hospital HSCT unit between 2019 and 2022 were reviewed retrospectively. Diagnosis of the patients, age at the time of HSCT, gender, presence of hypersensitivity reaction to rabbit-ATG, and management were evaluated. Characteristics of the reaction and presence of hypersensitivity reaction to other drugs were also noted. If performed, desensitization protocols were evaluated retrospectively. Results: We evaluated 81 patients; 66.6% of them (n = 54) were boys. The mean age of the patients was 8.78 ± 5.48 years. Hypersensitivity to rabbit-ATG was seen in six patients (7.4%). Four of them (4.9%) had anaphylaxis; two (2.4%) had urticaria. Intradermal test performed to every patient before the first dose of ATG infusion was detected a positive result in 1 patient (1.2%) . None of these seven patients had allergic reactions to other drugs before. Successful ATG desensitization was performed in five patients by using a 12-16 step protocol due to patients' reaction severity. Conclusion: This study aimed to evaluate hypersensitivity reactions with rabbit-ATG in children. A successful desensitization protocol with rabbit-ATG is presented. Desensitization must be performed with an experienced team very carefully in the absence of alternative drug.

The Effects of Vitamin D on Myocardial Function Demonstrated by Speckle-Tracking Echocardiography in Children with Beta Thalassemia.

OBJECTIVE: Beta thalassemia major is an inherited hemoglobin disorder resulting in chronic hemolytic anemia. Cardiac involvement is the main cause of death in patients. Speckle-tracking echocardiography is a feasible method for the evaluation of cardiac function via an assessment of the longitudinal deformation of the myocardium through the cardiac cycle. The aim of our study is to evaluate the association between vitamin D deficiency and deformation of the left ventricular myocardium measured by speckle-tracking echocardiography in children with thalassemia major. METHODS: In this prospective study, 33 thalassemic patients with vitamin D deficiency were enrolled. Cardiac magnetic resonance T2* value, conventional echocardiography, and speckle tracking, and also left ventricular longitudinal and circumferential strain values were measured. Myocardial functions of the patients with vitamin D deficiency or insufficiency were evaluated by speckle-tracking echocardiography before and after vitamin D replacement. RESULTS: The mean age of the patients was 15.4 ± 3.09 years. Vitamin D level was deficient in 30 (90%) and insufficient in 3 (10%) of them. Speckle-tracking analysis showed a significantly decreased absolute value of the left ventricular global longitudinal strain before vitamin D replacement. A significant improvement in the global longitudinal strain was detected after vitamin D replacement (P < 0.05). A statistically significant increase was observed in parameters showing left ventricular systolic and diastolic functions after vitamin D replacement. CONCLUSION: Vitamin D deficiency is frequently observed and causes decreased contractility in thalassemic patients. In our study, we observed that our patients' cardiac functions had improved after vitamin D replacement therapy.

Bone Marrow Grafts From Pediatric Donors May Contain A Considerable Number of Hematogones.

During CD34 + stem cell count to determine the number of stem cells in the allografts from pediatric donors, we noticed a considerable amount of early hematogones (eHGs) within the stem cell gate in flow cytometry. Since the number of hematogones causes a decrease in the total number of stem cells counted within the graft, we planned a retrospective study to analyze the effect of eHGs on transplant outcomes. We also wanted to show how allografts containing high amounts of early HGs affect transplant outcomes. Quantification of CD34 numbers and the number of eHGs were determined by flow cytometry. Patients were divided into 2 groups according to the number of CD 34+ cells calculated after subtracting the number of hematogones within the allograft. Those who received < 2 × 106/kg CD34+ cells and ≥ 2 × 106/kg were defined as group 1 and 2, respectively. Twenty-six patients and their 26 donors were included in the study. The median age of patients was 6.5 years and 5.4 years in Group 1 and 2, respectively. The median donor age was 9 years in Group 1 and 7 years in Group 2. The ages and genders were similar in the two groups (p > 0.05). The number of nucleated cells given to both groups was not different. The number of early hematogones given to both groups was similar (p = 0.93). The mean times to myeloid and platelet engraftments were also similar in the two groups. In this study, we provided trilineage engraftment to all patients in two groups. We could not find a considerable effect of these eHGs in myeloid and platelet engraftments. However, the number of patients included in our study is low, therefore we suggest a study including a large number of donors in order to confirm our findings.

Hematopoietic stem cell transplantation activities and HRQOL of refugee or asylum seeker children in Turkey: A multicenter study.

BACKGROUND: Refugee or asylum seekers (RAS) children are at increased risk of physical, developmental, and behavioral health issues. The aim of this study was to evaluate clinical and psychosocial outcomes of hematopoietic stem cell transplantation (HSCT) in RAS children and compare health-related quality of life (HRQOL) to those of Turkish peers. METHODS: This retrospective study included patients who underwent HSCT aged 0-18 years and completed 100-day post-transplant. The PedsQL 4.0 Generic Core Scale was used in children over 5 years old to compare HRQOL. RESULTS: A total of 166 RAS patients (M/F: 106 /60) underwent 174 HSCTs (six patients had two, and one had three HSCT) compared to 66 Turkish patients. The mean age of the patients in the RAS group was 7.8 ± 4.9 years and similar to controls. A total of 124 patients (75%) were from Syria, and 49 (25%) were from other countries in the Middle East and Africa. The cause of migration was war in 121 (74%) RAS patients. Complications of HSCT were no different between the groups. However, the rate of neutropenic sepsis was significantly higher in the RAS group (p = 0.004). The total scores of HRQOL were not different between RAS and controls. In the RAS group, ratings of social functioning were lower in patients with consanguinity or non-malignant disease or who had match-related donors. DISCUSSION: Identifying areas of difficulty in subscales of HRQOL may help physicians to classify patients who need additional supportive care. Regular monitoring and supporting physical needs may result in better functional outcomes after HSCT.

Role of therapeutic drug monitoring of intravenous Busulfan for prevention of sinusoidal obstructive syndrome in children.

BACKGROUND: Therapeutic drug monitoring (TDM) of intravenous busulfan (Bu) has been recommended for safe engraftment and decreased toxicity in children undergoing hematopoietic stem cell transplantation (HSCT). This study aims to compare HSCT-related outcomes, such as acute or chronic graft-versus-host disease (GvHD), sinusoidal obstructive syndrome (SOS), event-free survival (EFS), and overall survival (OS) in children with and without TDM for busulfan. METHODS: This retrospective study conducted between February 2012 and February 2021 at our Bone Marrow Transplantation Unit included 172 patients (34% girls) with a median age of 4.70 years (IQR 2.41-10.01). Group A consisted of 46 patients whose Bu doses were adjusted according to actual body weight, and group B consisted of 126 patients whose Bu dose adjustments made according to TDM. RESULTS: Totally, 32 patients (19%) developed moderate or severe SOS. The incidence of SOS was significantly higher in the group without TDM (29% vs. 15%, p = .041). A multivariable analysis showed that the presence of acute GvHD and one alkylating drug-containing conditioning regimen compared with two or three were associated with SOS (p = .03 and p = .002, respectively). In patients with TDM, cumulative Bu dose and area under curve also were not associated with SOS. Other HSCT-related outcomes such as acute or chronic GvHD, relapse and graft rejection rates, OS and EFS rates did not differ between the groups. CONCLUSIONS: TDM and making dose adjustments with Bayesian forecasting over four days of Bu therapy optimizes exposure and reduces the risk of SOS in children undergoing HSCT.

Antifungal Therapy in Pediatric Acute Lymphoblastic Leukemia: A Single-center Experience.

INTRODUCTION: Invasive fungal infections (IFIs) are significant causes of morbidity and mortality in leukemia patients. This study investigated antifungal treatment and prophylaxis features according to leukemia risk groups and treatment phases in pediatric acute lymphoblastic leukemia (ALL) patients who received Berlin-Frankfurt-Munster-based protocols. MATERIALS AND METHODS: We retrospectively examined ALL patients' data between the ages of 1 and 18 and treated them with Berlin-Frankfurt-Munster-ALL protocols between June 2013 and December 2016. RESULTS: A total of 446 febrile neutropenic attacks in 85 children were evaluated. Seventy-two patients received antifungals in 151 infection attacks, while 13 patients did not receive any antifungal treatment during chemotherapy. Empirical, preemptive, or proven treatments were given to 74.8%, 21.2%, and 4% of patients, respectively. The frequency of antifungal therapy increased linearly and significantly from the standard-risk group to the intermediate-risk (IR) group, high-risk (HR) group, and relapsed group. IR patients needed more antifungal therapy while receiving induction, whereas HR patients needed more throughout the induction and HR consolidation blocks than other phases. During induction, IR patients received antifungal therapy similar to HR patients' treatment in the induction and HR consolidation blocks. CONCLUSIONS: Antifungal therapy requirements increased as the severity and intensity of chemotherapy increased for all leukemia risk groups. The requirement of antifungal therapy for IR patients receiving induction was similar to that of HR patients; further studies are needed to evaluate the potential advantages of using primary antifungal prophylaxis in IR patients.

Evaluation of early-onset cardiotoxic effects of anthracyclines used during the treatment of childhood acute lymphoblastic leukemia by speckle-tracking echocardiography.

OBJECTIVE: Anthracyclines are widely used in the treatment of acute lymphoblastic leukemia (ALL). However, cardiotoxicity is the most critical side effect that requires dose limitation. It is thought to occur at first exposure, but the clinical presentation may occur years later. In this study, we aimed to determine the time of initial damage and cardiotoxicity that develops in children with ALL. METHODS: In this prospective study, 13 patients with newly diagnosed intermediate-risk precursor B cell ALL treated with the ALL-IC BFM 2009 protocol were included. Conventional echocardiography, tissue Doppler imaging (TDI), and speckle-tracking echocardiography (STE) were performed in all the patients before chemotherapy, after completing the induction phase, and at the end of the reinduction phase. RESULTS: The mean age of the patients was 7.8±4.6 (3.1-16.3) years. Myocardial velocity during systole (Sm) determined by TDI at the interventricular septum significantly decreased during the induction phase. Despite a decrease in STE parameters, a statistically significant reduction was determined in the global longitudinal strain rate at both left and right ventricles at the end of the induction. Nevertheless, a statistically significant increase was observed among the conventional echocardiographic findings in the left ventricular end-diastolic diameter at the end of the reinduction. CONCLUSION: During the treatment of ALL, subclinical anthracycline-associated cardiotoxicity develops in the early stages of treatment. The findings detected by TDI and STE could be missed by conventional echocardiography. We recommend evaluating patients with these newly developed techniques to detect subclinical cardiotoxicity at an early stage and starting appropriate therapy on time.

Pneumatosis cystoides intestinalis: A rare complication after hematopoietic stem cell transplantation.

BACKGROUND: Pneumatosis cystoides intestinalis (PCI) is a disorder in which widespread air sacs are present in mucosa, submucosa, subserosa, and intraabdominal area of the intestinal wall. It has a heterogeneous clinical presentation as a rare complication of intestinal graft-versus-host disease (GVHD). Computed tomography is the preferred imaging method for the diagnosis. Since the air sacs could be ruptured spontaneously, the presence of free air in the peritoneal cavity does not confirm intestinal perforation. The conservative treatment approach is sufficient in cases that do not require urgent surgical intervention, such as perforation or obstruction. CASE: Here, we present a 2.5-year-old patient diagnosed with primary hemophagocytic lymphohistiocytosis (pHLH), who underwent allogeneic hematopoietic stem cell transplantation from a matched unrelated donor (MUD) and developed PCI secondary to intestinal GVHD 14th months after HSCT. CONCLUSIONS: Pneumatosis cystoides intestinalis, which is a rare complication, should be kept in mind, especially in patients with intestinal GVHD and receiving intensive immunosuppressive, octreotide, and steroid treatment after HSCT.

Loss of C2orf69 defines a fatal autoinflammatory syndrome in humans and zebrafish that evokes a glycogen-storage-associated mitochondriopathy.

Human C2orf69 is an evolutionarily conserved gene whose function is unknown. Here, we report eight unrelated families from which 20 children presented with a fatal syndrome consisting of severe autoinflammation and progredient leukoencephalopathy with recurrent seizures; 12 of these subjects, whose DNA was available, segregated homozygous loss-of-function C2orf69 variants. C2ORF69 bears homology to esterase enzymes, and orthologs can be found in most eukaryotic genomes, including that of unicellular phytoplankton. We found that endogenous C2ORF69 (1) is loosely bound to mitochondria, (2) affects mitochondrial membrane potential and oxidative respiration in cultured neurons, and (3) controls the levels of the glycogen branching enzyme 1 (GBE1) consistent with a glycogen-storage-associated mitochondriopathy. We show that CRISPR-Cas9-mediated inactivation of zebrafish C2orf69 results in lethality by 8 months of age due to spontaneous epileptic seizures, which is preceded by persistent brain inflammation. Collectively, our results delineate an autoinflammatory Mendelian disorder of C2orf69 deficiency that disrupts the development/homeostasis of the immune and central nervous systems.

Children With Behçet Disease-associated Thrombosis: A Single-Center Experience.

Behçet disease (BD) is a systemic vasculitis that can be complicated with thrombosis, which is an important cause of mortality and morbidity. The course of BD is more severe, and the diagnosis is usually delayed. In children, thrombosis associated with BD is very rare. In this study, we aimed to evaluate the characteristics of children with BD complicated with thrombosis. Forty-six patients with BD who were followed-up at a pediatric rheumatology department between January 2012 and September 2019 were evaluated retrospectively. Thrombosis was detected in 10 patients (21.7%), and it was the first sign of BD in 7 patients. Four patients had cerebral sinus venous thrombosis, 4 patients had deep-vein thrombosis, 1 patient had renal vein thrombosis, 1 had pulmonary artery thrombosis, and 1 had intracardiac thrombosis. None of the patients had arterial thrombosis. All patients had received anticoagulant therapy with immunosuppressive treatment. Any complication due to anticoagulant therapy was not detected. One patient had recurrent thrombosis, and none of the patients died during follow-up. Vasculitic diseases such as BD may cause a predisposition to thrombosis, and thrombosis might be the first sign of BD. Therefore, in children presenting with unprovoked thrombosis, BD should also be investigated.

Renal function and the oxidative status among children with thalassemia major and healthy controls: A cross-sectional study.

BACKGROUND: Renal dysfunction is an underestimated complication of thalassemia major. OBJECTIVES: The aim of this study is to compare the glomerular and tubular functions in children with ß- Thalassemia major (ß- TM) with healthy controls and assess the oxidative stress caused by high ferritin levels. DESIGN AND SETTING: This prospective cross-sectional study was conducted in tertiary care hospital. METHODS: Complete blood count (CBC), calcium (Ca), urea, creatinine (Cr), serum cystatin C before transfusion and urinary calcium (uCa), creatinine (uCr), protein (UPr) levels were analyzed in fresh samples. Beta-2-microglobulin (uß2-MG), N- acetylglucosaminidase (uNAG), retinol binding protein (uRBP), malonedialdehyde (uMDA) secretion and creatinine levels were analyzed. Serum total antioxidant capacity (sTAC) and total oxidant capacity (sTOC) were measured with colorimetric micro-ELISA method. Last four serum ferritin values were recorded and the mean value was used for statistical analyzes. RESULTS: Data from 47 patients and 32 controls were analyzed. The urinary RBP/Cr, Ca/Cr and Protein/Cr, were significantly higher in ß-TM group. A statistically insignificant increase in urinary ß2MG/Cr, uNAG/Cr, MDA/Cr was also found in the TM group. Proteinuria was present in 46 % (n: 22) and hypercalciuria in 34 % (n: 16) of the patients with ß- TM. Serum total antioxidant capacity and total oxidant status (TOS) levels were significantly elevated in the patient group. Serum ferritin was significantly correlated with proteinuria, cystatin C levels, urinary Protein/Cr and uRBP/Cr. CONCLUSION: Asymptomatic renal dysfunction is prevalent in ß- TM patients that necessitate regular screening. Urinary RBP may be useful for early diagnosis.

Bone Marrow Necrosis in a Patient Following Blinatumomab Therapy.

Bone marrow necrosis (BMN) is an extremely rare condition characterized by necrosis of the myeloid tissue and medullary stroma leaving an amorphous eosinophilic background and ill-defined necrotic cells in the hematopoietic bone marrow. Several conditions are associated with BMN, including sickle cell disease, metastatic carcinoma, and hematologic malignancies. It is also associated with the use of antineoplastic drugs, such as fludarabine, interferon alpha, and imatinib. Blinatumomab is a CD19/CD3 bispecific T-cell engager antibody which redirects autologous CD3-positive T cells to CD19-positive lymphoblasts creating a cytolytic synapse leading to blastic cells. Cytokine release syndrome, cerebral nervous system toxicities, and febrile neutropenia are the most frequent adverse effects of blinatumomab. Here, we report an adolescent boy with relapse/resistant acute lymphoblastic leukemia developing BMN following blinatumomab therapy. To our knowledge, this is the first case report on BMN following blinatumomab treatment.

Management of acquired aplastic anemia in children : A single center experience.

Acquired aplastic anemia (AAA) is a rare and potentially life threatening disorder. We retrospectively compared the outcomes of 29 children with AAA who received immunosuppressive therapy (IST) or underwent hematopoietic stem cell transplantation (HSCT). Median age at diagnosis was 9.0 years (range, 2-18 years) and median follow-up period was 36 months (range, 3-108 months). Viral infection associated/post hepatitis AAA was in 6 patients (20.6%). According to the initial laboratory findings, 8 patients were classified as very severe AA (vSAA), 8 as severe AA (SAA), and 13 patients as transfusion-dependent moderate AA (MAA). Out of 13, 5 transfusion-dependent MAA patients progressed SAA in median one month (range, 1-5 months), another 6 MAA patients developed remission or became transfusion free during follow-up. Eight patients underwent upfront matched family donor (MFD) HSCT at median 6 months (range, 1-9 months) and achieved complete response (100%). Fifteen cycles of IST were given to 10 (34%) patients lacking MFD at median 3 months (range, 2-6 months). Fifty percent of patients had complete/partial response after IST protocol. Three patients who were unresponsive to IST, proceeded to alternative donor HSCT, in 2nd or 3rd year after the diagnosis and only 1 patient was sustained remission. Several drugs such as mycophenolatemofetil, high-dose cyclophosphamide, levamisole and eltrombopag have been investigated in order to improve the outcome of patients with AAA. Early intervention in AAA patients results in significantly better outcomes.

Retrospective evaluation of children with immune thrombocytopenic purpura and factors contributing to chronicity.

OBJECTIVE: Immune thrombocytopenic purpura (ITP) is the most common cause of acquired thrombocytopenia children. The aim of this retrospective study is to describe presenting features and clinical characteristics of ITP and evaluate clinical course, treatment modalities, and complications and determine the effects of preceding infection history, age, gender, treatment modality, and admission platelet count on chronicity. METHOD: Two hundred and eleven patients who were diagnosed ITP and followed-up in Department of Pediatric Hematology, Ankara Children Hematology Oncology Education and Research Hospital between January 2008 and September 2012 were included. Age of the patients, gender, date of admission, date of diagnosis, complaint in the application, previous infection and laboratory tests were recorded. RESULTS: Mean age of the patients on diagnosis was 5.4 ± 4.1 years. The female/male ratio was 1.03. The clinical courses were determined as acute or chronic in 72% and 28% of patients respectively. Mean age at diagnosis was significantly higher in chronic ITP (p < 0.01). Chronic course was significantly higher in female patients (p < 0.05). The most frequent complaint was bruises on the skin (68%). The most common physical examination findings were petechiae, purpura and ecchymosis (89%). Patients with a history of past infection (53.6%) and who had serologically positive infection (15.6%) frequently had acute course (p < 0.01). The most common serologically positive infection was Rubella. The mean platelet count was significantly higher in chronic ITP (p < 0.01). In the initial treatment of patients admitted in the acute phase, megadose methylprednisolone (MDMP) was used in 31% of patients, intravenous immune globulin (IVIG) in 55% of patients and anti-D in 2% of patients while 12% did not receive any treatment. There were no significant differences between the recurrence rate and treatment modality (p > 0.05). CONCLUSION: In our study, in females and in patients without any history of past infection, platelet count >20 × 109/L and initial diagnosis age > 10 years were found to increase the probability of chronic disease, which is compatible with the literature.