RESUMO
BACKGROUND: Veno-occlusive disease (VOD), also known as sinusoidal obstruction syndrome (SOS), is a life-threatening complications of hematopoietic cell transplantation (HCT). METHODS: We studied the impact of early defibrotide (DF) therapy on the outcomes of pediatric patients with VOD/SOS after transplantation, focusing on recent immunotherapies. A total of 111 pediatric patients who underwent HCT for malignant disease between February 2017 and March 2023 at Kyushu University Hospital were included. RESULTS: Among 111 patients of less than 20 years of age who underwent HCT for malignancy at a single institution between 2017 and 2023, VOD/SOS occurred in 25 (23%) patients. VOD/SOS developed more frequently in the post-DF era (2020-2023, n = 58) than in the pre-DF era (31% vs. 13%, p = .04). The proportion of patients with relapsed/refractory acute lymphoblastic leukemia (ALL) was higher in the post-DF era than in the pre-DF era (44% vs. 8%, p = .04). Early DF therapy that was started at two European Society for Blood and Marrow Transplantation diagnostic criteria reduced the severity of VOD/SOS (p < .01) in comparison to non-early therapy started at less than two criteria. A multivariate analysis indicated that a history of cytokine release syndrome (odds ratio [OR] = 10.4, p = .01) and juvenile myelomonocytic leukemia (OR = 8.98, p = .04), but not an endothelial activation and stress index (EASIX) score of greater than 0.85, were independent risk factors for VOD/SOS. CONCLUSIONS: Early DF therapy improves the severity and survival outcomes of post-transplant VOD/SOS in children. However, its incidence is increasing in the era of immunotherapy for progressive diseases.
Assuntos
Transplante de Células-Tronco Hematopoéticas , Hepatopatia Veno-Oclusiva , Polidesoxirribonucleotídeos , Humanos , Hepatopatia Veno-Oclusiva/etiologia , Polidesoxirribonucleotídeos/uso terapêutico , Masculino , Criança , Feminino , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Pré-Escolar , Adolescente , Fatores de Risco , Lactente , Estudos Retrospectivos , Seguimentos , Fibrinolíticos/uso terapêutico , Fibrinolíticos/efeitos adversos , Prognóstico , Taxa de Sobrevida , Adulto Jovem , AdultoRESUMO
The exposure of family caregivers to anticancer drugs for pediatric patients with malignancy is a potential health risk that needs to be minimized. We monitored the amount of cyclophosphamide (CPM) that had adhered to the undershirts of patients and the personal protective equipment (PPE) of family caregivers as well as the caregivers' urine levels of CPM within the first three days after the first and second courses of high-dose CPM therapy. Liquid chromatography/mass spectrometry (LC/MS/MS) detected >0.03 ng/ml of CPM in 26% (23/88) of urine samples from 8 of 11 (72.7%) patients' family caregivers, with a peak of 0.7 ng/ml from 24 to 48 h after administration. Since urine CPM concentrations in family caregivers varied after the first and second courses, the exposure risk factors were analyzed by scoring the PPE-wearing time index (caring minutes × PPE points from wearing masks, gloves, and/or gowns) and CPM adhesion of PPE items with the caring patterns of diaper change, washing body care, oral care, eating assistance, emotional support, and co-sleeping. The closest association was observed for CPM adhesion between oral care gloves and undershirts (correlation coefficient 0.67, p = 0.001). The mixed-effect model analysis indicated only a significant correlation between the PPE-wearing time index and emotional care (playing, cuddling, and physical contact) (p = 0.016). These results suggest that prolonged emotional support results in poor PPE protection, which increases the risk of exposure in family caregivers. Strict PPE care within 48 h after high-dose CPM controls the exposure to high-risk anticancer drugs in caregivers of pediatric patients.
Assuntos
Cuidadores , Ciclofosfamida , Neoplasias , Humanos , Cuidadores/psicologia , Ciclofosfamida/urina , Feminino , Masculino , Criança , Pré-Escolar , Adulto , Equipamento de Proteção Individual , Lactente , Adolescente , Exposição Ambiental/análise , Antineoplásicos Alquilantes/uso terapêutico , Fatores de Risco , Pessoa de Meia-IdadeRESUMO
The clinical spectrum of Down syndrome (DS) ranges from congenital malformations to premature aging and early-onset senescence. Excessive immunoreactivity and oxidative stress are thought to accelerate the pace of aging in DS patients; however, the immunological profile remains elusive. We investigated whether peripheral blood monocyte-derived dendritic cells (MoDCs) in DS patients respond to lipopolysaccharide (LPS) distinctly from non-DS control MoDCs. Eighteen DS patients (age 2-47 years, 12 males) and 22 controls (age 4-40 years, 15 males) were enrolled. CD14-positive monocytes were immunopurified and cultured for 7 days in the presence of granulocyte-macrophage colony-stimulating factor and IL-4, yielding MoDCs in vitro. After the LPS-stimulation for 48 hours from days 7 to 9, culture supernatant cytokines were measured by multiplex cytokine bead assays, and bulk-prepared RNA from the cells was used for transcriptomic analyses. MoDCs from DS patients produced cytokines/chemokines (IL-6, IL-8, TNF-α, MCP-1, and IP-10) at significantly higher levels than those from controls in response to LPS. RNA sequencing revealed that DS-derived MoDCs differentially expressed 137 genes (74 upregulated and 63 downregulated) compared with controls. A gene enrichment analysis identified 5 genes associated with Toll-like receptor signaling (KEGG: hsa04620, Pâ =â 0.00731) and oxidative phosphorylation (hsa00190, Pâ =â 0.0173) pathways. MoDCs obtained from DS patients showed higher cytokine or chemokine responses to LPS than did control MoDCs. Gene expression profiles suggest that hyperactive Toll-like receptor and mitochondrial oxidative phosphorylation pathways configure the immunoreactive signature of MoDCs in DS patients.
Assuntos
Citocinas , Células Dendríticas , Síndrome de Down , Lipopolissacarídeos , Monócitos , Humanos , Síndrome de Down/imunologia , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Masculino , Feminino , Adolescente , Adulto , Criança , Lipopolissacarídeos/imunologia , Lipopolissacarídeos/farmacologia , Monócitos/imunologia , Monócitos/metabolismo , Pré-Escolar , Pessoa de Meia-Idade , Citocinas/metabolismo , Adulto Jovem , Células CultivadasRESUMO
Although killer Ig-like receptor ligands (KIR-L) mismatch has been associated with alloreactive natural killer cell activity and potent graft-versus-leukemia (GVL) effect among adults with acute myeloid leukemia (AML), its role among children with AML receiving cord blood transplantation (CBT) has not been determined. We conducted a retrospective study using a nationwide registry of the Japanese Society for Transplantation and Cellular Therapy. Patients who were diagnosed with de novo non-M3 AML and who underwent their first CBT in remission between 2000 and 2021 at under 16 years old were included. A total of 299 patients were included; 238 patients were in the KIR-L match group, and 61 patients were in the KIR-L mismatch group. The cumulative incidence rates of neutrophil recovery, platelet engraftment, and acute/chronic graft-versus-host disease did not differ significantly between the groups. The 5-year event-free survival (EFS) rate was 69.8% in the KIR-L match group and 74.0% in the KIR-L mismatch group (p = 0.490). Stratification by CD34 + cell dose into four groups revealed a significant correlation between CD34 + cell dose and EFS in the KIR-L mismatch group (p = 0.006) but not in the KIR-L match group (p = 0.325). According to our multivariate analysis, KIR-L mismatch with a high CD34 + cell dose (≥ median dose) was identified as an independent favorable prognostic factor for EFS (hazard ratio = 0.19, p = 0.029) and for the cumulative incidence of relapse (hazard ratio = 0.09, p = 0.021). Our results suggested that higher CD34 + cell doses are crucial for achieving a potent GVL effect in the context of KIR-L-mismatched CBT.
Assuntos
Antígenos CD34 , Transplante de Células-Tronco de Sangue do Cordão Umbilical , Leucemia Mieloide Aguda , Receptores KIR , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Doença Enxerto-Hospedeiro/etiologia , Leucemia Mieloide Aguda/terapia , Leucemia Mieloide Aguda/mortalidade , Estudos RetrospectivosAssuntos
Rearranjo Gênico , Histona-Lisina N-Metiltransferase , Leucemia Mieloide Aguda , Mutação , Proteína de Leucina Linfoide-Mieloide , Proteínas Proto-Oncogênicas p21(ras) , Humanos , Proteína de Leucina Linfoide-Mieloide/genética , Leucemia Mieloide Aguda/genética , Histona-Lisina N-Metiltransferase/genética , Prognóstico , Proteínas Proto-Oncogênicas p21(ras)/genética , Feminino , Pessoa de Meia-Idade , Masculino , Adulto , Idoso , Adulto JovemRESUMO
Gaucher disease (GD) is a lysosomal storage disorder caused by a deficiency in the GBA1-encoded enzyme, ß-glucocerebrosidase. Enzyme replacement therapy is ineffective for neuronopathic Gaucher disease (nGD). High-dose ambroxol has been administered as an alternative treatment for a group of patients with nGD. However, little is known about the clinical indication and the long-term outcome of patients after ambroxol therapy. We herein report a case of a female patient who presented with a progressive disease of GD type 2 from 11 months of age and had the pathogenic variants of p.L483P (formerly defined as p.L444P) and p.R502H (p.R463H) in GBA1. A combined treatment of imiglucerase with ambroxol started improving the patient's motor activity in 1 week, while it kept the long-lasting effect of preventing the deteriorating phenotype for 30 months. A literature review identified 40 patients with nGD, who had received high-dose ambroxol therapy. More than 65% of these patients favorably responded to the molecular chaperone therapy, irrespective of p.L483P homozygous, heterozygous or the other genotypes. These results highlight the long-lasting effect of ambroxol-based chaperone therapy for patients with an expanding spectrum of mutations in GBA1.
Assuntos
Ambroxol , Doença de Gaucher , Doenças por Armazenamento dos Lisossomos , Humanos , Feminino , Doença de Gaucher/tratamento farmacológico , Doença de Gaucher/genética , Doença de Gaucher/patologia , Ambroxol/uso terapêutico , Terapia Combinada , Chaperonas MolecularesRESUMO
Severe obesity in young children prompts for a differential diagnosis that includes syndromic conditions. Rapid-Onset Obesity with Hypothalamic Dysfunction, Hypoventilation, and Autonomic Dysregulation (ROHHAD) syndrome is a potentially fatal disorder characterized by rapid-onset obesity associated with hypoventilation, neural crest tumors, and endocrine and behavioral abnormalities. The etiology of ROHHAD syndrome remains to be established, but recent research has been focusing on autoimmunity. We report on a 2-year-old girl with rapid-onset obesity during the first year of life who progressed to hypoventilation and encephalitis in less than four months since the start of accelerated weight gain. The patient had a high titer of anti-ZSCAN1 antibodies (348; reference range < 40), and the increased values did not decline after acute phase treatment. Other encephalitis-related antibodies, such as the anti-NDMA antibody, were not detected. The rapid progression from obesity onset to central hypoventilation with encephalitis warns about the severe consequences of early-onset ROHHAD syndrome. These data indicate that serial measurements of anti-ZSCAN1 antibodies might be useful for the diagnosis and estimation of disease severity. Further research is needed to determine whether it can predict the clinical course of ROHHAD syndrome and whether there is any difference in antibody production between patients with and without tumors.
Assuntos
Neoplasias das Glândulas Suprarrenais , Doenças do Sistema Nervoso Autônomo , Encefalite , Doenças Hipotalâmicas , Obesidade Infantil , Feminino , Humanos , Pré-Escolar , Hipoventilação/complicações , Hipoventilação/diagnóstico , Obesidade Infantil/complicações , Neoplasias das Glândulas Suprarrenais/complicações , Síndrome , Encefalite/complicaçõesRESUMO
INTRODUCTION: Children and adolescents with mature B cell non-Hodgkin lymphoma (B-NHL) are treated with short-intensive chemotherapy. The burden of short-term and long-term toxicity is highly relative to its high cure rate in good-risk patients. Although the addition of rituximab to standard lymphome Malin B (LMB) chemotherapy markedly prolongs event-free survival and overall survival in high-risk patients, the benefit of rituximab in good-risk patients remains to be elucidated. This clinical trial will examine whether the addition of rituximab eliminates anthracyclines in good-risk patients without compromising treatment outcomes. METHODS AND ANALYSIS: We will perform a single-arm, open-label, multicentre phase II study. Low-risk (stage I - completely resected, stage II abdominal) and intermediate-risk (stages I and II - incompletely resected; stage II - resected, other than abdominal; stage III with LDH <2× upper limit of normal) patients with newly diagnosed B-NHL are eligible. Low-risk patients receive two courses of R-COM1P (rituximab, cyclophosphamide, vincristine, methotrexate, prednisolone and intrathecal methotrexate with hydrocortisone), and intermediate-risk patients receive COP (cyclophosphamide, vincristine, prednisolone and intrathecal methotrexate with hydrocortisone) followed by two courses each of R-COM3P and R-CYM (rituximab, cytarabine, methotrexate and intrathecal methotrexate with hydrocortisone). The primary endpoint is a 3-year event-free survival rate in paediatric patients (<18 years) with intermediate-risk disease. 100 patients (10 low-risk and 90 intermediate-risk) will enrol within a 4-year enrolment period and the follow-up period will be 3 years. 108 institutions are participating as of 1 January 2024 (64 university hospitals, 29 general hospitals, 12 children's hospitals and three cancer centres). ETHICS AND DISSEMINATION: This research was approved by the Certified Review Board at NHO Nagoya Medical Center (Nagoya, Japan) on 21 September 2021. Written informed consent is obtained from all patients and/or their guardians. The results of this study will be disseminated through peer-reviewed publications and conference presentations. STUDY REGISTRATION: Japan Registry of Clinical Trials, jRCTs041210104.
Assuntos
Linfoma de Células B , Metotrexato , Humanos , Adolescente , Criança , Rituximab/uso terapêutico , Vincristina/uso terapêutico , Metotrexato/uso terapêutico , Antraciclinas , Hidrocortisona , Japão , Doxorrubicina/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Linfoma de Células B/tratamento farmacológico , Ciclofosfamida/uso terapêutico , Ciclofosfamida/efeitos adversos , Resultado do Tratamento , Antibióticos Antineoplásicos/uso terapêutico , Prednisolona/uso terapêutico , Estudos Multicêntricos como Assunto , Ensaios Clínicos Fase II como AssuntoRESUMO
BACKGROUND: Area postrema syndrome (APS), a rare childhood condition, manifests as intractable nausea and hiccups. APS has high diagnostic significance in neuromyelitis optica syndrome spectrum disorders (NMOSD) and can be the initial presentation of other critical diseases, including brainstem glioma. METHODS: We described two representative cases of unrelated Japanese patients with APS. An etiologic evaluation, including a detailed intracranial neuroradiological examination and autoantibodies assessment, was performed. We also reviewed the literature focusing on the prognosis of pediatric APS symptoms. RESULTS: A 14-year-old girl with aquaporin-4 antibody-positive NMOSD showed a good prognosis with immunotherapy, whereas another nine-year-old girl with irresectable medullary low-grade glioma had persistent symptoms for more than 10 years. All reported children aged >12 years were diagnosed with NMOSD, and patients aged <13 years showed heterogeneous etiologies. CONCLUSIONS: Distinctive time courses and neuroimaging features were key clinical findings for the diagnostic and therapeutic processes in these patients. This literature review highlights the wide spectrum and prognosis of pediatric-onset APS.
Assuntos
Glioma , Neuromielite Óptica , Feminino , Humanos , Criança , Adolescente , Área Postrema/diagnóstico por imagem , Vômito/etiologia , Neuromielite Óptica/complicações , Neuromielite Óptica/diagnóstico por imagem , Neuromielite Óptica/terapia , Náusea/etiologia , Síndrome , Autoanticorpos , Doenças Raras/complicações , Glioma/complicações , Aquaporina 4RESUMO
Purpose: Although fertility preservation for pediatric cancer patients is becoming more widespread in Japan, some facilities do not provide sufficient information regarding fertility. This study aimed to elucidate the problems pertaining to the lack of information about fertility among patients. Methods: Based on a 2020 survey, seminars addressing fertility preservation were held from the Designated Pediatric Cancer Care Hospitals in each of the seven blocks in Japan to their partner hospital (pediatric cancer hospitals). The seminar consisted of lectures and group discussions, and a questionnaire was also administered after each seminar. Results: In the group discussions, a lack of explanations to patients and explanatory materials for children were cited as issues by many facilities. The survey results revealed a lack of material explaining fertility preservation and a lack of knowledge among health care providers. There were also many requests to use the patient explanation videos presented at the seminar. Conclusion: The results indicate that further education for health care providers by seminar and other sources and enhancement of explanatory materials are important for fertility preservation in pediatric cancer hospitals in Japan.
Assuntos
Preservação da Fertilidade , Neoplasias , Humanos , Criança , Preservação da Fertilidade/métodos , Japão , Neoplasias/terapia , Fertilidade , Serviços de Saúde , Inquéritos e QuestionáriosRESUMO
ABSTRACT: Occupational exposure to medical agents and ionizing radiation has been suggested as a possible risk factor for childhood cancer. However, the relationship between such exposure and pediatric malignant neoplasms has not yet been comprehensively studied. This cohort study aimed to investigate the association between parental occupational exposure to hazardous medical agents or ionizing radiation and the risk of childhood cancer in offspring. Data from a large birth cohort in Japan, which included 104 062 fetuses, were analyzed. The primary outcome was the development of leukemia or brain tumors diagnosed by community physicians during the first 3 years after birth. Exposure factors were medical agents, including anticancer agents, ionizing radiation, and anesthetics, handled by mothers during pregnancy or by fathers for 3 months before conception. The incidence of leukemia, but not of brain tumors, was higher in mothers exposed to anticancer drugs. Multivariable regression analysis showed that maternal exposure to anticancer drugs was associated with an increased risk of leukemia in offspring older than 1 year (adjusted relative risk, 7.99 [95% confidence interval, 1.98-32.3]). Detailed information obtained from medical certificates of patients with identified leukemia revealed no infant leukemia but acute lymphoblastic leukemias in the exposed group. Our findings suggest that maternal occupational exposure to anticancer drugs may be a potential risk factor for acute lymphoblastic leukemia in offspring older than 1 year. Effective prevention methods may be necessary to prevent maternal exposure to anticancer drugs and to reduce the risk of childhood malignant neoplasms.
Assuntos
Antineoplásicos , Neoplasias Encefálicas , Exposição Ocupacional , Leucemia-Linfoma Linfoblástico de Células Precursoras , Masculino , Gravidez , Feminino , Humanos , Criança , Exposição Materna/efeitos adversos , Exposição Paterna/efeitos adversos , Estudos de Coortes , Japão/epidemiologia , Fatores de Risco , Mães , Exposição Ocupacional/efeitos adversos , Antineoplásicos/efeitos adversos , Leucemia-Linfoma Linfoblástico de Células Precursoras/epidemiologia , Estudos de Casos e ControlesRESUMO
BACKGROUND: The benefit of adding rituximab to standard lymphomes malins B (LMB) chemotherapy for children with high-risk mature B-cell non-Hodgkin lymphoma (B-NHL) has previously been demonstrated in an international randomized phase III trial, to which the Japanese Pediatric Leukemia/Lymphoma Study Group could not participate. METHODS: To evaluate the efficacy and safety of rituximab in combination with LMB chemotherapy in Japanese patients, we conducted a single-arm multicenter trial. RESULTS: In this study, 45 patients were enrolled between April 2016 and September 2018. A total of 33 (73.3%), 5 (11.1%), and 6 (13.3%) patients had Burkitt lymphoma/leukemia, diffuse large B-cell lymphoma, and aggressive mature B-NHL, not otherwise specified, respectively. Ten (22.2%) and 21 (46.7%) patients had central nervous system disease and leukemic disease, respectively. The median follow-up period was 47.5 months. Three-year event-free survival and overall survival were 97.7% (95% confidence interval, 84.9-99.7) and 100%, respectively. The only event was relapse, which occurred in a patient with diffuse large B-cell lymphoma. Seven patients (15.6%) developed Grade 4 or higher non-hematologic adverse events. Febrile neutropenia was the most frequent Grade 3 or higher adverse event after the pre-phase treatment, with a frequency of 54.5%. CONCLUSION: The efficacy and safety of rituximab in combination with LMB chemotherapy in children with high-risk mature B-NHL was observed in Japan.
Assuntos
Linfoma de Burkitt , Leucemia , Linfoma Difuso de Grandes Células B , Humanos , Criança , Rituximab/efeitos adversos , Linfoma de Burkitt/tratamento farmacológico , Linfoma Difuso de Grandes Células B/diagnóstico , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Linfoma Difuso de Grandes Células B/etiologia , Intervalo Livre de Progressão , Leucemia/tratamento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversosRESUMO
Microglia play versatile roles in progression of and protection against neuroinflammatory diseases. Little is known, however, about the mechanisms underlying the diverse reactivity of microglia to inflammatory conditions. We investigated how human induced microglia-like (iMG) cells respond to innate immune ligands. Quantitative PCR showed that poly-I:C and lipopolysaccharide (LPS) activated the expression of IL1B and TNF. Immunoreactivity of iMG did not differ between controls (n = 11) and patients with neuroinflammatory diseases (n = 24). Flow cytometry revealed that CD14high cells expressed interleukin (IL) -1ß after LPS treatment. Immunoblotting showed that poly-I:C and LPS differentially activated inflammatory pathways but commonly induced mitochondrial instability and the expression of pyruvate kinase isoform M2 (PKM2). Furthermore, a potent stimulator of PKM2 (DASA-58) alleviated IL-1ß production after LPS treatment. These data indicate that heterogeneous cell populations and mitochondrial stability underlie the divergent immunoreactivity of human iMG in environments.
Assuntos
Microglia , Doenças Neuroinflamatórias , Humanos , Microglia/metabolismo , Lipopolissacarídeos/farmacologia , Citometria de Fluxo , Expressão GênicaRESUMO
INTRODUCTION: To establish actionable neonatal screening during the first month of life, we investigated critical diseases in seemingly healthy newborns discharged from birth hospitals. METHODS: This retrospective study enrolled previously healthy full-term infants who visited our hospital, a tertiary hospital in Japan, from home between 5 and 28 days after birth from 2009 to 2018. Infants with known perinatal or congenital diseases, positive newborn screening results, or accidental injuries were excluded. Data were collected from electronic medical records, including principal diagnosis, clinical details, and prognosis at 18 months of age. RESULTS: Ninety-seven (58 %) of 168 eligible neonates were admitted to the hospital, and 71 (42 %) were not. The median admission rate in patients with disease onset at ≤14 days after birth (80 %) was significantly higher than that in patients with disease onset at ≥15 days (42 %). Among 45 patients who received intensive medical care, 5 died and 10 developed neurodevelopmental sequelae. Four of 5 patients died by 100 days. Among 25 diseases treated in intensive care unit, 17 (68 %) diseases had a prevalence of <1 per 2000 live births. The commonly used diagnostic methods were imaging (n = 58, 35 %) and physical examination (n = 34, 20 %). CONCLUSION: Critical diseases due to rare and heterogeneous causes in ostensibly healthy newborns occurred predominantly in the first two weeks of life. Optimal newborn screening and health check-up protocols may benefit from the wide spectrum of life-threatening diseases occurring in home after birth.
Assuntos
Triagem Neonatal , Alta do Paciente , Humanos , Recém-Nascido , Unidades de Terapia Intensiva Neonatal , Japão/epidemiologia , Estudos Retrospectivos , Centros de Atenção TerciáriaRESUMO
Introduction: Glucarpidase (CPG2) reduces the lethal toxicity of methotrexate (MTX) by rapid degradation. Methods: In this study, a CPG2 population pharmacokinetics (popPK) analysis in healthy volunteers (phase 1 study) and a popPK-pharmacodynamics (popPK-PD) analysis in patients (phase 2 study, n = 15) who received 50 U/kg of CPG2 rescue for delayed MTX excretion were conducted. In the phase 2 study, the first CPG2 treatment at a dose of 50 U/kg was intravenously administered for 5 min within 12 h after the first confirmation of delayed MTX excretion. The second dose of CPG2, with a plasma MTX concentration >1 µmol/L, was administered to the patient more than 46 h after the start of CPG2 administration. Results: The population mean PK parameters (95% CI) of MTX, obtained from the final model post hoc, were estimated as follows: CLrMTX = 2.424 L/h (95% CI: 1.755-3.093), VcMTX = 12.6 L (95% CI: 10.8-14.3), VpMTX = 2.15 L (95% CI: 1.60-2.70), and α = 8.131 x 105 (4.864 x 105-11.398 x 105). The final model, including covariates, was CLrMTX (L/h): 3.248 x Body Weight/Serum creatinine/60 (CV 33.5%), VcMTX (L): 0.386 x Body Weight/body surface area (CV 29.1%), VpMTX (L):3.052 x Body Weight/60 (CV 90.6%), and α (L/h): 6.545 x 105 (CV 79.8%). Discussion: These results suggest that the pre-CPG2 dose and 24 h after CPG2 dosing were the most important sampling points in the Bayesian estimation of plasma MTX concentration prediction at 48 h. These CPG2-MTX popPK analysis and Bayesian estimation of rebound in plasma MTX concentrations are clinically important to estimate >1.0 µmol/L 48 h after the first CPG2 dosing. Clinical trial registration: https://dbcentre3.jmacct.med.or.jp/JMACTR/App/JMACTRS06/JMACTRS06.aspx?seqno=2363, identifier JMA-IIA00078 and https://dbcentre3.jmacct.med.or.jp/JMACTR/App/JMACTRS06/JMACTRS06.aspx?seqno=2782, identifier JMA-IIA00097.