Publications by authors named "Yoshiyuki Kosaka"

Background: This study aimed to evaluate whether an early elevation of absolute eosinophil count after allogeneic hematopoietic stem cell transplantation (allo-HSCT) was associated with the development of chronic graft-versus-host disease (cGVHD) in children and adolescents.

Methods: A total of 165 consecutive patients who received allo-HSCT were included in the study. Patients who had previously received allo-HSCT, relapsed or died before Day 100, and did not achieve engraftment, were excluded.

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Aplastic anemia, mental retardation, and dwarfism syndrome (AMeDS) is a rare inherited bone marrow failure syndrome. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the only possible treatment option for hematological complications in AMeDS; however, there are no reports addressing allo-HSCT for AMeDS. A 6-year-old female diagnosed with AMeDS accompanying myelodysplastic syndrome with increased blast was successfully treated with cord blood transplantation followed by myeloablative conditioning (MAC).

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Purpose: The JCCG ALL-B12 clinical trial aimed to evaluate the effectiveness of unvalidated treatment phases for pediatric ALL and develop a safety-focused treatment framework.

Patients And Methods: Patients age 1-19 years with newly diagnosed B-ALL were enrolled in this study. These patients were stratified into standard-risk (SR), intermediate-risk (IR), and high-risk (HR) groups.

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Article Synopsis
  • This study focused on children aged 0-18 years with severe (ST) and extreme thrombocytosis (ET), analyzing over 120 patients with platelet counts exceeding 900,000/µL to understand their causes and clinical outcomes.
  • The most common underlying conditions were congenital heart disease and Kawasaki disease, with only a small percentage showing primary thrombocytosis and a low incidence of thrombosis.
  • It was found that lower hemoglobin levels at the onset of thrombocytosis were linked to the development of ET, indicating potential differences in how thrombocytosis manifests in children compared to adults.
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The Japan Children's Cancer Group Relapsed Acute Lymphoblastic Leukemia (ALL) Committee conducted a prospective observational study (ALL-R14) to explore promising reinduction therapy regimens for relapsed ALL to investigate in future trials. In Japan, clofarabine- and bortezomib-based regimens were of interest since they were newly introduced for ALL in the study period (2015-2018). Seventy-five pediatric patients were enrolled in total.

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Non-high-risk (non-HR) neuroblastoma (NB) patients have excellent outcomes, with more than a 90% survival rate, whereas HR NB patients expect less than a 50% survival rate. Metastatic disease is the principal cause of death among both non-HR and HR NB patients. Previous studies have reported the significant but limited prognostic value of quantitative PCR (qPCR)-based assays, measuring overlapping but different sets of neuroblastoma-associated mRNAs (NB-mRNAs), to detect metastatic disease in both non-HR and HR patient samples.

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Background: Although neurotoxicity is a major adverse event associated with busulfan, little information is available regarding the association between drug interactions and neurological symptoms during busulfan-based regimens. This study evaluated the association between prophylactic echinocandins and neurological complications in patients receiving busulfan-containing conditioning regimens for stem cell transplantation.

Methods: We retrospectively included consecutive patients who administered intravenous busulfan as a conditioning regimen at our facility between 2007 and 2022.

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Recently, heterozygous loss-of-function NFKB1 variants were identified as the primary cause of common variable immunodeficiency (CVID) in the European population. However, pathogenic NFKB1 variants have never been reported in the Japanese population. We present a 29-year-old Japanese woman with CVID.

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Survival rates of patients with Philadelphia chromosome-positive ALL (Ph+ALL) have improved considerably with the introduction of tyrosine kinase inhibitors (TKI); however, hematopoietic stem cell transplantation (HSCT) continues to play an important role. Reduced-intensity conditioning (RIC) regimens have been widely applied particularly for older patients, but their validity for children and adolescents with Ph+ALL has not been investigated. In this study, data from patients receiving HSCT for de novo Ph+ALL in first or second remission at ages younger than 25 years and with a history of pre-HSCT TKI therapy were retrospectively collected through the nationwide registry in Japan.

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Article Synopsis
  • The "Otsuka" minor BCR-ABL messenger RNA assay kit was developed for precise assessment of minor BCR-ABL levels in patients with Philadelphia chromosome-positive acute lymphoblastic leukemia (ALL), an important factor for prognosis and treatment planning.
  • Testing showed that the "Otsuka" kit performed reliably, with results aligning closely with established methods and demonstrating strong correlations with other diagnostic tests.
  • The findings suggest that the "Otsuka" kit could be a significant advancement in understanding and treating Philadelphia chromosome-positive ALL, given its high precision and effectiveness compared to conventional diagnostic tools.
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Background: Tsukamurella spp. are obligate aerobic, gram-positive, non-motile, and slightly acid-fast bacilli belonging to the Actinomycetes family. They share many characteristics with Nocardia, Rhodococcus, Gordonia, and the rapidly growing Mycobacterium species.

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Purpose: To investigate the dose stability of craniospinal irradiation based on irradiation method of proton beam therapy (PBT).

Methods And Materials: Twenty-four pediatric and young adult brain tumor patients (age: 1-24 years) were examined. Treatment method was passive-scattered PBT (PSPT) in 8 patients and intensity-modulated PBT (IMPT) in 16 patients.

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Article Synopsis
  • * Typically, MRD is evaluated more effectively in BM than in PB, but this case highlights a 3-year-old girl with HR-NB who had unexpectedly higher PB-MRD levels compared to BM-MRD prior to her relapses.
  • * Despite initially achieving complete remission through standard treatment, the patient experienced two relapses, with monitoring showing that PB-MRD levels increased remarkably before each relapse, suggesting that PB-MRD could be a significant indicator for evaluating
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Background: The present study aimed to examine the association between the conditioning intensity and height growth in pediatric patients who underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT).

Methods: We reviewed the clinical records of 89 children with malignant diseases who underwent initial allo-HSCT between 2003 and 2021. Height measurements were standardized using standard height charts prepared by the Japanese Society for Pediatric Endocrinology to calculate standard deviation score (SDS).

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Article Synopsis
  • This study assessed the effectiveness of two different proton beam therapy methods—passive scattered PBT (PSPT) and intensity modulated PBT (IMPT)—in treating pediatric patients requiring craniospinal irradiation.
  • It involved 24 patients, with a follow-up of 17 to 44 months, and compared the doses received by critical organs in two groups: one using the whole vertebral body technique and the other using the vertebral body sparing (VBS) technique.
  • Results indicated that IMPT resulted in lower doses to sensitive areas like the lens and improved coverage of the planning target volume (PTV), while the VBS technique effectively reduced radiation exposure to surrounding organs.
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Background: T-cell acute lymphoblastic leukaemia has distinct biological characteristics and a poorer prognosis than B-cell precursor acute lymphoblastic leukaemia. This trial aimed to reduce the rate of radiation and haematopoietic stem-cell transplantation (HSCT) while improving outcomes by adding nelarabine, intensified L-asparaginase, and protracted intrathecal therapy in the Berlin-Frankfurt-Münster (BFM)-type treatment.

Methods: In this nationwide, multicenter, phase 2 trial, we enrolled patients with newly diagnosed T-cell acute lymphoblastic leukaemia (age <25 years at diagnosis) conducted by Japan Children's Cancer Group and Japan Adult Leukemia Study Group.

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Treatment outcomes for children with relapsed and refractory acute lymphoblastic leukemia (R/R-ALL) remain poor, and the optimal induction therapy has not been determined. Bortezomib is a proteasome inhibitor that acts synergistically and additively with standard chemotherapy for ALL. We evaluated the efficacy and safety of combination chemotherapy with bortezomib in children with R/R-ALL.

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Chemotherapy with cytarabine, vincristine (VCR), and prednisolone has achieved low mortality rates in pediatric patients with Langerhans cell histiocytosis (LCH). However, relapse rates remain high, making event-free survival (EFS) rates unsatisfactory. A nationwide clinical trial, LCH-12, tested a modified protocol in which the early maintenance phase was intensified with increasing dosages of VCR.

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Article Synopsis
  • * SIRPα, a protein found in immune cells, is identified as a potential treatment target for LCH, as it is present in cells related to the disease in both humans and mouse models.
  • * Treatment with a specific antibody targeting SIRPα reduced the number of certain immune cells in the blood and liver lesions, and enhanced the ability of macrophages to eliminate the harmful cells associated with LCH.
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Background: Coagulase-negative staphylococci can cause hospital-acquired infections, especially in immunocompromised hosts. Bacterial meningitis is a potentially fatal infection of the central nervous system, causing high mortality and morbidity. In general, the causative agents of meningitis, coagulase-negative staphylococci, are associated with direct implantation of a foreign body and the presence of a cerebrospinal fluid (CSF) shunt.

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