Potential diagnostic and prognostic biomarkers of pediatric Burkitt lymphoma identified through miRNA expression profiling.

BACKGROUND: Pediatric Burkitt lymphoma (pBL) is the most common non-Hodgkin lymphoma in children. These patients require prompt diagnosis and initiation of therapy due to rapid tumor growth. The roles of tumor tissue and circulating microRNAs (miRNAs) in the diagnosis or prognostication have not been fully elucidated in pBLs. METHODS: Differentially expressed (DE) miRNAs were identified with microRNA sequencing (miRNA-Seq) in tumor tissues and plasma of diagnostic pBLs. The diagnostic potential of total miRNA concentrations and overexpressed miRNAs were evaluated through receiver operating characteristic (ROC) analyses. Log-rank test was employed to evaluate survival differences associated with DE miRNAs. Selected miRNA expressions were cross-validated with quantitative reverse transcription PCR (qRT-PCR). RESULTS: Total circulating cell-free miRNAs were higher in pBL cases compared to controls. Cancer-associated pathways were enriched among miRNAs differentially expressed in pBL tumor tissues. Several upregulated miRNAs in pBL tumors demonstrated high diagnostic potential. Similarly, ROC analysis of overexpressed plasma miRNAs revealed circulating cell-free or exosomal miRNAs that can distinguish pBLs from control cases. Indeed, integrative analysis of overexpressed circulating exosomal miRNAs showed an enhanced diagnostic potential for certain triple combinations. Kaplan-Meier analyses of DE miRNAs in tumor tissues identified miRNAs predicting overall survival. CONCLUSIONS: Differentially expressed miRNAs in tumor tissue and plasma of pBL have the potential to improve diagnosis and prognosis. IMPACT: Differentially expressed miRNAs in treatment-naive pediatric Burkitt lymphoma cases have diagnostic or prognostic biomarker potential. This is the first study that applied miRNA-Seq on treatment-naive pediatric Burkitt lymphoma cases for identification of differentially expressed miRNAs both in tumor tissue and plasma samples with diagnostic potential. Through systematic analysis of differentially expressed miRNAs, tumor tissue miRNAs associated with the overall survival of pBLs have been discovered. The clinically significant, differentially expressed miRNAs identified in pediatric Burkitt lymphoma cases can potentially improve the current tissue-based or non-invasive clinical practice in terms of diagnosis or prognostication.

Hematopoietic stem cell transplantation with reduced toxicity conditioning regimen in mitochondrial neurogastrointestinal encephalopathy syndrome.

BACKGROUND: Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) is a rare autosomal recessive disorder due to mutations in the TYMP gene. Clinical findings are characterized by neurologic manifestations and severe gastrointestinal dysfunction. The syndrome is usually fatal, the most effective treatment appears to be hematopoietic stem cell transplantation (HSCT). PROCEDURE: In this retrospective study, we evaluated HSCT that was performed using a reduced toxicity myeloablative conditioning regimen in patients with MNGIE at our center. RESULTS: A total of six allogeneic transplant procedures were performed in four patients. Three patients had fully matched donors, and one patient had a haploidentical donor. Treosulfan-based myeloablative conditioning regimen was applied in five of six transplants. Bone marrow was used as a stem cell source. One patient is being followed up in the 4th year of posttransplant with full chimeric and without graft versus host disease (GVHD). One patient died of acute stage IV gastrointestinal system GVHD. Two patients underwent second transplantation due to engraftment failure, one of which was the patient who had a haploidentical transplant. CONCLUSIONS: Treosulfan-based regimen is well tolerated, although engraftment failure with this conditioning regimen can be a significant problem. We share our haploidentical transplant experience, which will be the first reported case in the literature.

Management of a Patient With Congenital Biallelic CSF3R Mutation With GM-CSF.

Severe Congenital Neutropenia (SCN) is a rare inherited disease characterized by an absolute neutrophil count (ANC) lower than 500/µL. Genetic heterogeneity and biallelic CSF3R mutation has rarely been identified as an underlying genetic defect in SCN. The majority of SCN patients respond to granulocyte colony stimulating factor treatment; however, in patients with inherited CSF3R mutation, ANC cannot generally be increased with granulocyte colony stimulating factor treatment. In such cases, granulocyte macrophage colony stimulating factor presents as an effective treatment option. Herein, we report a case of a 5-year-old SCN girl with homozygous c610-611 del ins AG (p.Q204R) mutation in the CSF3R gene, who was successfully treated with granulocyte macrophage colony stimulating factor.

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.

Utility of the serum galactomannan assay for the diagnosis of invasive aspergillosis in children with acute lymphoblastic leukemia.

OBJECTIVES: Invasive aspergillosis (IA) is an important cause of mortality and morbidity in children with hematological malignancies. The monitoring of serum galactomannan (GM) antigen is considered useful in the diagnosis of IA . The aim of this study was to determine the utility of serum GM monitoring in the early diagnosis of IA and the role of positive antigenemia in the management of children with acute lymphoblastic leukemia (ALL). METHODS: The cases of 141 children who were being treated for ALL in the Division of Pediatric Hematology of the Medical School of Ege University between January 2006 and February 2015 were reviewed retrospectively. Cases of proven and probable IA were defined according to the European Organization for the Research and Treatment of Cancer/Mycoses Study Group (EORTC/MSG) criteria. RESULTS: The incidence of proven and probable IA was 3.5% (5/141). The incidence of positive GM antigenemia among 3264 serum samples was 5.5% (n=179). Of the cases detected, 21.7% were true-positive, 52.1% were false-positive, and the remaining 26.1% were classified as 'undetermined.' An increase in the incidence of true-positive tests and induction of antifungal therapy was determined through multiple consecutive positive tests. CONCLUSIONS: GM may be detected in the serum before the clinical signs of IA appear, but its sensitivity and specificity are variable. False-positivity is a significant disadvantage, and consecutive positive GM must be taken into account in the case of clinical and imaging findings that are relevant to IA.

Rare severe mycotic infections in children receiving empirical caspofungin treatment for febrile neutropenia

ABSTRACTEmpirical antifungal therapy is most often given to patients with leukemia. However breakthrough fungal infections under antifungal therapy are not uncommon. Four children, with hematologic malignant disease developed mycotic breakthrough infections while on empirical caspofungin treatment for a median of 14 (range 11-19) days. Trichosporon asahii was detected in the blood culture of two patients and Geotrichum capitatum in the other two (one patient also had positive cerebrospinal fluid culture). Because the patients' clinical situation worsened, voriconazole was empirically added for two patients three and five days before the agent was detected. The first sterile blood culture was obtained 3-7 days of voriconazole treatment. All patients reached clear cultures but one patient died. One patient with central nervous system infection with G. capitatum had severe neurological sequelae. Very severe fungal infections can occur during empirical caspofungin therapy. Therefore, patients should be followed closely.