RESUMEN
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. Prophylactic echinocandin use was defined as the use of an echinocandin antifungal drug to prevent invasive fungal disease in SCT recipients. The primary outcome was the incidence of neurological complications within 7 days of busulfan initiation and was compared between the echinocandin group (patients received prophylactic echinocandin) and nonechinocandin group (patients received prophylactic antifungal drugs other than echinocandin and those without antifungal prophylaxis). RESULTS: Among the 59 patients included in this study, the incidence of neurological complications in the echinocandin (n = 26) and nonechinocandin groups (n = 33) was 30.8% and 63.6%, respectively. We observed a negative association between prophylactic echinocandin use and the development of neurological complications after adjusting for the propensity score for receiving prophylactic echinocandins (adjusted odds ratio 0.294, 95% confidence interval 0.090 to 0.959). We observed a lower incidence of neurological complications in the echinocandin group than in the nonechinocandin group. CONCLUSION: Our results suggested that the choice of antifungal prophylaxis is associated with busulfan neurotoxicity.
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Enfermedad Injerto contra Huésped , Trasplante de Células Madre Hematopoyéticas , Enfermedades del Sistema Nervioso , Humanos , Busulfano/efectos adversos , Estudios Retrospectivos , Antifúngicos/uso terapéutico , Equinocandinas/uso terapéutico , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Trasplante de Células Madre Hematopoyéticas/métodos , Trasplante de Células Madre , Enfermedades del Sistema Nervioso/etiología , Acondicionamiento Pretrasplante/efectos adversos , Acondicionamiento Pretrasplante/métodos , Enfermedad Injerto contra Huésped/etiologíaRESUMEN
The clinical characteristics, cause, and risk factors of sarcopenia are unclear in children. The aim of this study was to describe the course of and identify the factors related to muscle mass change during chemotherapy in children with neuroblastoma. A total of 24 consecutive patients aged below 18 years with newly diagnosed high-risk neuroblastoma between 2010 and 2018 in our hospital were enrolled in a case-series study. The psoas muscle index (PMI) was calculated as a parameter of muscle mass based on computer tomography (CT) images of the psoas muscle. PMIs were evaluated at 4 time points (TPs): TP1, at the diagnosis of neuroblastoma; TP2, after the first cycle of chemotherapy; TP3, after the third cycle of chemotherapy; and TP4, at the end of the induction chemotherapy. PMI recovery was defined as an increase in PMI between TP2 and TP4. The mean PMI decreased by 15% between TP1 and TP2 (TP1 7.09 ± 0.99 vs. TP2 6.01 ± 0.98, P < 0.001) and by 10% between TP1 and TP4 (TP1 7.09 vs. TP4 6.35, P = 0.004). PMI recovery between TP1 and TP2 was observed in 7 (29%) patients. The median age of patients with PMI recovery was significantly lower (2 vs. 4 years, P = 0.028), and the proportion of boys was significantly higher in patients with PMI recovery (100% vs. 41%, P = 0.017).Conclusion: This study demonstrated that prominent PMI reduction occurs during the early time of chemotherapy, and a younger age and male sex may be predictive factors for PMI recovery. What is Known: ⢠Sarcopenia is a common disorder in elderly people. ⢠Several causes and risk factors have been reported in adults. ⢠Children with previous hematological malignancies have decreased physical activity. What is New: ⢠Prominent muscle mass loss was observed early in children with high-risk neuroblastoma during chemotherapy. ⢠Age and sex were found to be potentially associated with muscle mass recovery.
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Neuroblastoma , Sarcopenia , Adulto , Anciano , Niño , Humanos , Masculino , Neuroblastoma/diagnóstico por imagen , Neuroblastoma/tratamiento farmacológico , Neuroblastoma/patología , Músculos Psoas/diagnóstico por imagen , Músculos Psoas/patología , Estudios Retrospectivos , Sarcopenia/patología , Tomografía Computarizada por Rayos XRESUMEN
This prospective observational study analyzed the pharmacokinetics of busulfan in Japanese children and evaluated the predicting accuracy of previous pediatric PPK models of busulfan. This study enrolled five patients (aged 2-12 years, BW 14-48 kg) receiving a busulfan-based conditioning regimen for hematopoietic stem cell transplantation at our hospital between January 2017 and December 2018. All patients received a 2-hour intravenous busulfan infusion four times daily for a total of 16 doses. After the infusions, 51 plasma samples were collected with the plasma busulfan concentration measured by liquid chromatography-tandem mass spectrometry. PPK model fitting was analyzed using the (%MPE) and the (%MAPE). Limited sampling strategies for estimating busulfan AUC were also evaluated. High interpatient variability was observed in the PK parameters. The most suitable PPK model that reflected our data was McCune's two-compartment model (%MPE -8.7, %MAPE 19.3). A combination sampling method using the busulfan concentration at 2 and 6 hours after the start of the first busulfan dose was found to be able to estimate AUC4 day . These results provide useful information on busulfan therapeutic drug monitoring in the Japanese pediatric population.
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Busulfano/farmacocinética , Monitoreo de Drogas/métodos , Trasplante de Células Madre Hematopoyéticas , Agonistas Mieloablativos/farmacocinética , Acondicionamiento Pretrasplante/métodos , Niño , Preescolar , Femenino , Humanos , Japón , Masculino , Modelos Teóricos , Estudios ProspectivosRESUMEN
We report two malignant sacrococcygeal tumors in infants that were associated with pathogenic DICER1 variation. These tumors were composed of primitive neuroepithelium, embryonal rhabdomyosarcoma, and cartilage and initially diagnosed as immature teratomas. One child developed intracranial metastasis and died. The second child underwent surgery and chemotherapy and achieved complete remission. This child subsequently developed five additional DICER1-associated neoplasms by age nine. Genetic analysis revealed that both tumors harbored biallelic pathogenic DICER1 variation. We believe these cases represent another novel subtype of DICER1-associated tumor. This new entity, which we propose to call DICER1-associated presacral malignant teratoid neoplasm, may be difficult initially to distinguish from immature teratoma, but recognizing it as an entity can prompt appropriate classification as an aggressive malignancy and facilitate appropriate genetic counseling, DICER1 germline variant testing, screening, and education.
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ARN Helicasas DEAD-box/genética , Ribonucleasa III/genética , Teratoma/genética , Femenino , Predisposición Genética a la Enfermedad , Mutación de Línea Germinal , Humanos , Recién Nacido , Masculino , Región Sacrococcígea , Teratoma/patologíaRESUMEN
The dismal prognosis of pediatric acute myeloid leukemia (AML) relapsing after hematopoietic stem cell transplantation (HSCT) requires exploration of novel strategies to prevent relapse. Azacitidine (AZA) maintenance therapy could potentially reduce the recurrence rate post HSCT. Here, we presents the cases of three children with high-risk AML post HSCT who were treated with low-dose AZA maintenance therapy, demonstrating the feasibility of this therapy. Currently, all three are in complete remission for 13-41 months despite their high-risk characteristics. Our encouraging data warrant larger prospective studies to assess the efficacy and safety of low-dose AZA maintenance therapy post HSCT for pediatric patients with high-risk AML.
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Antimetabolitos Antineoplásicos/uso terapéutico , Azacitidina/uso terapéutico , Leucemia Mieloide Aguda/tratamiento farmacológico , Quimioterapia de Mantención/métodos , Recurrencia Local de Neoplasia/prevención & control , Adolescente , Preescolar , Femenino , Trasplante de Células Madre Hematopoyéticas , Humanos , Leucemia Mieloide Aguda/cirugía , Masculino , Inducción de Remisión , Estudios RetrospectivosRESUMEN
We herein reported a 4-month-old boy with transplantation-associated atypical hemolytic uremic syndrome (TA-aHUS) who was successfully treated with eculizumab. The patient diagnosed with type 3 of familial hemophagocytic lymphohistiocytosis underwent cord blood transplantation. After transplantation, he developed TA-aHUS, but plasma exchanges were unsuccessful. We identified deletions in CFH-related gene 1 (del-CFHR1) by the multiplex ligation-dependent probe amplification testing procedure and CFH autoantibodies. Eculizumab has been administered to the patient, with a marked improvement being achieved in thrombocytopenia. He has been well except for the persistent microhematuria for a year after transplantation. Uncontrolled complement activation might be involved in the pathophysiology of TA-aHUS.
Asunto(s)
Anticuerpos Monoclonales Humanizados/administración & dosificación , Síndrome Hemolítico Urémico Atípico/tratamiento farmacológico , Trasplante de Células Madre de Sangre del Cordón Umbilical/efectos adversos , Síndrome Hemolítico Urémico Atípico/etiología , Autoanticuerpos/inmunología , Factor H de Complemento/deficiencia , Factor H de Complemento/inmunología , Enfermedades por Deficiencia de Complemento Hereditario , Humanos , Lactante , Enfermedades Renales , Linfohistiocitosis Hemofagocítica/complicaciones , Linfohistiocitosis Hemofagocítica/terapia , Masculino , Intercambio Plasmático , Resultado del TratamientoRESUMEN
BACKGROUND: Optimal prevention of chemotherapy-induced vomiting (CIV) has not been established for patients receiving cisplatin in divided doses. The aim of this study was to describe the incidence and risk factors of CIV in children who received multiple-day cisplatin chemotherapy. PROCEDURE: A total of 24 consecutive pediatric patients (age 0-19 years) who received multiple-day cisplatin chemotherapy in our hospital were enrolled. Patients with relapsed disease or primary intracranial tumor and those who received concurrent radiation therapy were excluded. The number of chemotherapy cycles reviewed was 107, with a median of five per patient. All patients received granisetron. Dexamethasone and NK-1 receptor antagonists (NK1RA) were used as additional antiemetics for prophylaxis of CIV. RESULTS: CIV was observed in 22 of 24 (92%) patients, and 61 of 107 (57%) cycles. Patients who developed CIV had a higher incidence of other chemotherapy-related adverse events (87 vs. 41%, P < 0.001). The incidence of CIV was lower in patients administered with NK1RA than those without (32 vs. 68%, P < 0.001). Multivariate logistic regression identified age less than or equal to 2 years (odds ratio [OR] = 0.25, 95% confidence interval [CI] = 0.10-0.63) and administration of NK1RA (OR = 0.16, 95% CI = 0.06-0.43) as independent factors for CIV. CONCLUSIONS: These results suggest that NK1RA is crucial to reduce CIV in children who receive multiple-day cisplatin chemotherapy.
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Antineoplásicos/efectos adversos , Cisplatino/efectos adversos , Vómitos/inducido químicamente , Vómitos/prevención & control , Adolescente , Antieméticos/uso terapéutico , Niño , Preescolar , Estudios de Cohortes , Femenino , Humanos , Incidencia , Lactante , Recién Nacido , Masculino , Neoplasias/tratamiento farmacológico , Antagonistas del Receptor de Neuroquinina-1/uso terapéutico , Estudios Retrospectivos , Factores de Riesgo , Vómitos/epidemiología , Adulto JovenRESUMEN
A 10-year-old girl was referred to our hospital with left preauricular adenopathy and gingival swelling. She was diagnosed with B-cell precursor acute lymphoblastic leukemia (BCP-ALL) based on being positive for expressions of CD10, CD19, TdT and HLA-DR. She showed no CD20 expression at the time of diagnosis. Based on the initial diagnosis of BCP-ALL, induction chemotherapy for BCP-ALL was initiated. However, the blasts did not disappear from her peripheral blood. Bone marrow examination on day 33 identified 81.3% residual blasts with positive expressions of CD19, 20 and HLA-DR and negative CD10 and TdT expressions; these cells were morphologically and phenotypically different from those at the initial diagnosis. Based on cytogenetic studies, the final diagnosis was double-hit lymphoma/leukemia (DHL) with IgH-BCL2 and Igλ-MYC. Although dose intensive chemotherapy, including rituximab, led to complete remission, bone marrow and central nervous system relapse occurred. At relapse, blasts expressed CD10, CD19 and HLA-DR, but not CD20, findings the same as those at the onset. The patient died of the disease 44 days after cord blood transplantation with non-remission status. DHL in childhood is extremely rare and its prognosis is poor. The establishment of an effective treatment for DHL is highly anticipated.
Asunto(s)
Inmunofenotipificación , Linfoma de Células B/patología , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnóstico , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Rituximab/uso terapéutico , Médula Ósea/patología , Niño , Femenino , Humanos , Linfoma de Células B/inmunología , Leucemia-Linfoma Linfoblástico de Células Precursoras/inmunología , Resultado del TratamientoAsunto(s)
Factor IX , Hemofilia B , Factor IX/genética , Hemofilia B/genética , Humanos , Japón , Masculino , Mutación , Regiones Promotoras Genéticas , HermanosRESUMEN
We herein describe a 2-year-old boy with severe congenital neutropenia (SCN) who was successfully treated with reduced-intensity bone marrow transplantation (HSCT). He had suffered recurrent episodes of bacterial pneumonia from 12 months of age, and was found to have severe neutropenia with white blood cell counts below 100/µl. The patient harbored a heterozygous missense mutation in ELANE exon 4 (p.Gln134Pro, NM_001972.2: c.401A>C). This was a novel mutation. Due to intractable pneumonia and severe persistent neutropenia, reduced-intensity HSCT was performed from an HLA-matched sibling donor. The preparative regimen consisted of melphalan, fludarabine, and 4 Gy of total body irradiation. Hematopoietic engraftment was rapidly obtained, i.e., by day +14, and complete donor chimerism was subsequently achieved. The lung complications observed pre-transplantation markedly improved after neutrophil recovery, i.e., by day +60. We concluded that HSCT is a useful treatment for SCN patients, especially for those at high risk of leukemic transformation. Fludarabine-based reduced-intensity HSCT may represent a safe and effective therapeutic option for patients with SCN who need HSCT even if they have intractable infectious complications.
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Trasplante de Médula Ósea , Neutropenia/congénito , Infarto Pulmonar/complicaciones , Preescolar , Enfermedad Crónica , Síndromes Congénitos de Insuficiencia de la Médula Ósea , Humanos , Masculino , Mutación Missense , Neutropenia/complicaciones , Neutropenia/genética , Neutropenia/terapia , Trasplante HomólogoRESUMEN
We report a 4-year-old boy with severe congenital neutropenia (SCN), who was successfully treated with hematopoietic stem cell transplantation (HSCT). The patient had frequently developed bacterial infections since 6 months of age, and showed severe neutropenia below 100/µl at 1 year and 4 months of age. The patient harbored a heterozygous missense mutation in ELANE exon 3 (p.Q73P, g.2253 A>C). This was a novel de novo mutation, and he was thus diagnosed as having SCN. Because of failure to respond to granulocyte colony-stimulating factor treatment and repeated admissions due to bacterial infections, allogeneic HSCT was performed from a serologically matched unrelated donor following the conditioning regimen: fludarabine/melphalan/anti-thymocyte globulin and a low dose of total body irradiation. Tacrolimus and a short course of methotrexate were used for graft-versus-host disease prophylaxis. Engraftment was achieved at day 12, and the patient maintained normal hematopoiesis for over 15 months after HSCT. We concluded that HSCT is a useful treatment for SCN patients, especially those who are at high risk for leukemic transformation. However, a larger number of SCN patients and longer follow-up are necessary to identify appropriate conditioning regimens and long-term prognosis.
Asunto(s)
Trasplante de Células Madre Hematopoyéticas , Elastasa de Leucocito/genética , Mutación Missense , Neutropenia/congénito , Aloinjertos , Síndromes Congénitos de Insuficiencia de la Médula Ósea , Enfermedad Injerto contra Huésped/prevención & control , Humanos , Inmunosupresores/administración & dosificación , Lactante , Masculino , Metotrexato/administración & dosificación , Neutropenia/genética , Neutropenia/terapia , Tacrolimus/administración & dosificación , Acondicionamiento Pretrasplante/métodos , Resultado del TratamientoRESUMEN
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. A novel variant, c.136 C > T, p.(Gln46*), was identified in NFKB1. Her mother and daughter carried the same variant, demonstrating the first Japanese pedigree with an NFKB1 pathogenic variant.
RESUMEN
Haematopoietic stem-cell transplantation (HSCT)-associated thrombotic microangiopathy (HSCT-TMA) is a serious complication with high mortality. Accumulating evidence suggests that complement dysregulation is potentially involved in the development of HSCT-TMA. We retrospectively analysed the clinical characteristics and outcomes of thirteen paediatric patients who were diagnosed with atypical haemolytic uremic syndrome and treated with eculizumab to manage HSCT-TMA during post-marketing surveillance in Japan. The median time from HSCT to TMA was 31 days (Interquartile range, IQR;21-58) and the median doses of eculizumab was three (IQR;2-5). Seven patients (54%) were alive at the last follow-up while six died due to complications related to HSCT. Six of seven survivors initiated eculizumab after insufficient response to plasma therapy. Following eculizumab treatment, median platelet counts and LDH levels in all survivors significantly improved and renal function improved in 4/7 patients. All survivors possessed potential risk factors of complement overactivation. During the follow-up period after eculizumab discontinuation (median;111.5 days, IQR;95-555), no TMA recurrence was observed. In this analysis, eculizumab showed benefit in over half of this paediatric patient population. Ongoing clinical studies are expected to optimize the treatment regimen of terminal complement pathway inhibitor, and it may become a therapeutic option for paediatric HSCT-TMA in the future.
Asunto(s)
Anticuerpos Monoclonales Humanizados , Trasplante de Células Madre Hematopoyéticas , Microangiopatías Trombóticas , Niño , Humanos , Japón , Estudios Retrospectivos , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Inactivadores del Complemento/efectos adversos , Microangiopatías Trombóticas/tratamiento farmacológico , Microangiopatías Trombóticas/etiología , Microangiopatías Trombóticas/diagnóstico , Vigilancia de Productos ComercializadosRESUMEN
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. A droplet digital PCR (ddPCR)-based assay measuring seven NB-mRNAs (CRMP1, DBH, DDC, GAP43, ISL1, PHOX2B, and TH mRNAs) was recently developed and exhibited a better prognostic value for HR patient samples than qPCR-based assays. However, it remained to be tested on non-HR patient samples. In the present study, we employed the ddPCR-based assay to study peripheral blood (PB) and bone marrow (BM) samples collected at diagnosis from eight non-HR and eleven HR cases and characterized the expression profiles of NB-mRNAs. The most highly expressed NB-mRNAs in PB and BM differed between non-HR and HR cases, with the CRMP1 mRNA being predominant in non-HR cases and the GAP43 mRNA in HR cases. The levels of NB-mRNAs in PB and BM were 5 to 1000 times lower in non-HR cases than in HR cases. The PB to BM ratio of NB-mRNAs was 10 to 100 times higher in non-HR cases compared to HR cases. The present case series suggests that non-HR and HR NB patients have the distinct expression profiles of NB-mRNAs in their PB and BM.
RESUMEN
A girl, aged 19 months, presented with a sacrococcygeal tumor that developed at 5 months after birth and gradually enlarged. Serum tumor marker levels were negative. Ultrasound imaging showed abundant blood flow in the tumor. However, neither computed tomography (CT) nor magnetic resonance imaging (MRI) showed contrast agent incorporation. The surgically resected tumor consisted of immature cells with myxoid stroma and proliferating small blood vessels. Immunostaining showed extensive vimentin expression. However, smooth muscle actin, muscle-specific actin, and S-100 protein expression was negative. Neither the ETV6-NTRK3 fusion gene nor the FUS gene rearrangement was detected. Thus, the patient was diagnosed with a primitive myxoid mesenchymal tumor of infancy. This tumor primarily consisted of a mucosal stroma with a low absorption on CT, a low signal on T1-weighted MRI, and a high signal on T2-weighted MRI. A diagnosis of primitive myxoid mesenchymal tumor of infancy should be considered in cases of soft tissue tumors in infants that show prominent vascularity but little contrast enhancement on MRI or CT.
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Neoplasias de Tejido Conjuntivo/diagnóstico , Neoplasias de los Tejidos Blandos/diagnóstico , Femenino , Humanos , Inmunohistoquímica , Lactante , Imagen por Resonancia Magnética , Neoplasias de Tejido Conjuntivo/cirugía , Región Sacrococcígea , Neoplasias de los Tejidos Blandos/cirugía , Tomografía Computarizada por Rayos XRESUMEN
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). We defined short stature as a height SDS less than -2.0 in that reference. Myeloablative conditioning (MAC) comprised total-body irradiation at more than 8 Gy and busulfan administration at more than 8 mg/kg (more than 280 mg/m2 ). Other conditioning regimens were defined as reduced intensity conditioning (RIC). RESULTS: A total of 58 patients underwent allo-HSCT with MAC, and 31 patients received allo-HSCT with RIC. There were significant differences in the height SDS at 2 and 3 years after allo-HSCT between MAC and RIC group (-1.33 ± 1.20 vs. -0.76 ± 1.12, p = 0.047, -1.55 ± 1.28 vs. -0.75 ± 1.11, p = 0.022, respectively). Multivariate logistic regression analysis with the adjustments for potential confounding factors of patients less than 10 years of age at allo-HSCT and chronic graft-versus host disease demonstrated that MAC regimen was associated with a markedly increased risk of a short stature at 3 years after allo-HSCT (adjusted odds ratio, 5.61; 95% confidence interval, 1.07-29.4; p = 0.041). CONCLUSION: The intensity of conditioning regimen may be associated with short statures after allo-HSCT.
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Síndrome de Bronquiolitis Obliterante , Enfermedad Injerto contra Huésped , Trasplante de Células Madre Hematopoyéticas , Humanos , Niño , Enfermedad Injerto contra Huésped/etiología , Enfermedad Injerto contra Huésped/prevención & control , Trasplante Homólogo , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Busulfano , Acondicionamiento Pretrasplante/efectos adversos , Estudios RetrospectivosRESUMEN
We herein report a rare case of spinal cord compression due to epidural involvement of acute myeloid leukemia (AML). A 14-year-old boy presented with a 7-day history of back pain, paraplegia and hypoesthesia. Contrast-enhanced computed tomography revealed an epidural mass. Emergency laminectomy and resection of the mass were performed. Histopathologically, the resected mass was comparable to an extramedullary mass of AML. Chemotherapy was initiated, and complete remission was achieved. Neurological sequelae remained after the treatment. Based on the present and previous reports, spinal cord compression from epidural AML involvement may progress rapidly.
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Leucemia Mieloide Aguda , Compresión de la Médula Espinal , Masculino , Humanos , Adolescente , Compresión de la Médula Espinal/diagnóstico por imagen , Compresión de la Médula Espinal/etiología , Compresión de la Médula Espinal/cirugía , Leucemia Mieloide Aguda/complicaciones , Leucemia Mieloide Aguda/diagnóstico , Progresión de la Enfermedad , Tomografía Computarizada por Rayos X/efectos adversos , Médula Espinal , Imagen por Resonancia Magnética/efectos adversosRESUMEN
OBJECTIVE: There is limited knowledge about muscle-mass loss in childhood and adolescent patients with cancer. The aim of this study was to investigate the association between muscle mass evaluated by computed tomography (CT) and the serum creatinine-cystatin C ratio (CCR) in children and adolescents with cancer. METHODS: Patients age <18 y with cancer who underwent abdominal CT scans and blood sampling for serum creatinine and cystatin C within 1 wk before or after the CT scan between 2017 and 2019 at our hospital were retrospectively enrolled. A measurement was defined as a set of abdominal CT scans and serum creatinine and cystatin C levels. The psoas muscle cross-sectional area (PMCSA) was defined as the psoas major muscle area at the level of the fourth lumbar vertebra on axial CT. Statistical tests and modeling were performed as measurement-based analyses. RESULTS: A total of 109 patients and 204 measurements were included in the analysis. CCR showed a strong positive correlation with PMCSA (r = 0.75; P < 0.001). The association between CCR and PMCSA was observed in all age groups and both sexes. There was a clear trend of increased PMCSA across quartile categories of CCR (P < 0.001). On multivariate, generalized, estimating, equation, linear regression model analysis, examining factors associated with PMCSA, male sex, body surface area, and CCR were independent parameters for PMCSA. CONCLUSIONS: These results suggest that CCR may be a useful surrogate marker for muscle mass in cancer care for children and adolescents.