Objectives: Although acute anterior cruciate ligament reconstruction (ACLR) is often avoided because of postoperative joint stiffness, delayed ACLR can lead to a longer recovery time and can have a negative impact on physical function due to detraining. This study aimed to determine the effects of acute ACLR on postoperative outcomes, including muscle strength, performance, and return to sports. Methods: A total of 110 patients who underwent anatomical ACLR using hamstring autografts were included in this study and were divided into three groups: acute (ACLR performed within 2 weeks after ACL injury), 2–6 weeks (ACLR performed between 2 and 6 weeks after injury), and 6–12 weeks (ACLR performed between 6 and 12 weeks after injury). Several parameters were evaluated, including range of motion, knee joint stability, isokinetic knee strength, performance, and return to sports. Results: No significant differences were found in the range of motion or knee joint stability between the groups. The acute group exhibited significantly greater quadriceps strength at 3 months postoperatively than the other groups (p < 0.05). The single-leg hop test showed that 66.7%, 38.7%, and 33.3% of the patients in the acute, 2–6 weeks, and 6–12 weeks groups, respectively, recovered to an LSI of 90% or greater (p = 0.09, Cramer’s V = 0.27). All patients in the acute group were able to return to sports (p = 0.14; Cramer’s V = 0.28). Conclusions: Acute ACLR is advantageous for the early recovery of strength and performance without adverse events. Acute ACLR may shorten the time spent away from sports activities.

Bone defects in the tibial tunnel for anterior cruciate ligament (ACL) reconstruction can cause adverse events. The unidirectional porous tricalcium beta-phosphate (UDPTCP) has the potential to be used as a filling substitute for bone defects. In this case series, we present the first nine cases in which UDPTCP was used as a bone substitute in the tibial tunnel during ACL reconstruction. The patients comprised six males and three females, with an average age of 32 years (range: 16-50 years). A cylindrical UDPTCP measuring 10 x 20 mm was molded to fit the tibial tunnel and then implanted. At the one-year postoperative follow-up, none of the patients demonstrated any complications, and bone remodeling was observed on radiographs. Therefore, UDPTCP may provide a safe and reliable filling substitute for the tibial tunnel in ACL reconstruction.

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-Munster (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. Patients were stratified into standard-risk, high-risk, and very-high-risk groups according to prednisolone response, CNS status, and end-of-consolidation minimal residual disease. We used the Associazione Italiana di Ematologia Oncologia Pediatrica (AIEOP)-BFM-ALL 2000-backbone chemotherapy. Nelarabine (650 mg/m2 per day for 5 days) was given to high-risk and very high-risk patients. All patients received, until the measurement of end-of-consolidation minimal residual disease, an identical therapy schedule, which included the prednisolone pre-phase remission induction therapy with dexamethasone (10 mg/m2 per day, for 3 weeks [for patients <10 years] or for 2 weeks including a 7-day off interval [for patients & GE;10 years]) instead of prednisolone, and consolidation therapy added with Escherichia coli-derived L-asparaginase. On the basis of the stratification, patients received different intensities of treatment; L-asparaginase-intensified standard BFM-type therapy for standard risk and nelarabine-added high risk BFM-type therapy for high risk. In the very high-risk group, patients were randomly assigned (1:1) to group A (BFM-based block therapy) and group B (another block therapy, including high-dose dexamethasone) stratified by hospital, age (& GE;18 years or <18 years), and end-of-induction bone marrow blast percentage of M1 (<5%) or M2 (& GE;5%, <25%)+M3 (& GE;25%). Cranial radiotherapy was limited to patients with overt CNS disease at diagnosis (CNS3; >5 white blood cells per & mu;L with blasts) and patients with no evidence of CNS disease received protracted triple intrathecal therapy. Only very high-risk patients were scheduled to receive HSCT. The primary endpoint was 3-year event-free survival for the entire cohort and the proportion of patients with disappearance of minimal residual disease between randomly assigned groups A and B in the very high-risk group. Secondary endpoints were overall survival, remission induction rate, and occurrence of adverse events. 3 years after the completion of patient accrual, a primary efficacy analysis was performed in the full analysis set and the per-protocol set. This study is registered with the Japan Registry of Clinical Trials, jRCTs041180145.Findings Between Dec 1, 2011, and Nov 30, 2017, of 349 eligible patients (median age 9 years [IQR 6-13]), 238 (68%) were male, and 28 (8%) patients had CNS3 status. 168 (48%) patients were stratified as standard risk, 103 (30%) as high risk, 39 (11%) as very high risk, and 39 (11%) as no risk (patients who had off protocol treatment before risk assessment. The composite complete remission (complete remission plus complete remission in suppression) rate after remission induction therapy was 89% (298 of 335 patients). HSCT was performed in 35 (10%) of 333 patients. With a median follow-up of 5 & BULL;2 years (IQR 3 & BULL;6-6 & BULL;7), 3-year event-free survival was 86 & BULL;4% (95% CI 82 & BULL;3-89 & BULL;7%) and 3-year overall survival was 91 & BULL;3% (87 & BULL;7-93 & BULL;8%). The proportion of minimal residual disease disappearance was 0 & BULL;86 (12 of 14 patients; 95% CI 0 & BULL;57-0 & BULL;98) in group A and 0 & BULL;50 (6 of 12 patients, 0 & BULL;21-0 & BULL;79) in group B. Grade 3 peripheral motor neuropathy was seen in 11 (3%) of 349 patients and sensory neuropathy was seen in 6 (2%) patients. The most common grade 3 or worse adverse event was febrile neutropenia (294 [84%] of 349 patients). Treatment-related death occurred in three patients due to sepsis, gastric perforation, or intracranial haemorrhage during remission induction.Interpretation The ALL-T11 protocol produced encouraging outcomes with acceptable toxicities despite limited cranial radiotherapy and HSCT use.Copyright & COPY; 2023 Elsevier Ltd. All rights reserved.

This study aims to elucidate how self-efficacy influences cancer-related fatigue and health-related quality of life (HRQoL) in young survivors of childhood cancer. Forty-six young survivors (age range, 8–18 years) of childhood cancer who were currently in complete remission completed measures for self-efficacy (Pediatric General Self-Efficacy Scale (PedsSE)), cancer-related fatigue (Cancer-related Fatigue Score (CRFS)), and HRQoL (Pediatric Quality of Life Inventory 4.0 Generic Core Scale, Pediatric Quality of Life Inventory (PedsQL)). Structural relationships between the PedsSE and CRFS or PedsQL, including the effects of potential demographic or clinical confounders, were examined by machine learning random forest algorithms and structural equation modeling. According to the distribution of the PedsQL, six survivors with PedsQL < 70 were determined to have compromised HRQoL (referred to as “low-PedsQL survivors”). The random forest model identified six variables for the prediction of the CRFS, with the PedsSE being the most important, and eight variables for the distinction of low-PedsQL survivors, with the CRFS being the most and the PedsSE the third most important variable. The structural equation model indicated that a direct influence of the PedsSE on the PedsQL was less detectable (β = −0.049), whereas an indirect influence of the PedsSE on the PedsQL via the CRFS was evident (β = 0.333). The model explained 51% of the variation of the CRFS and 28% of the variation of the PedsQL. The PedsSE was strongly correlated with “altered mood” in the subclass of the CRFS (r = −0.470), and “altered mood” was strongly correlated with the PedsQL (r = 0.737). In conclusion, self-efficacy is a major determinant of cancer-related fatigue and influences HRQoL via cancer-related fatigue in survivors of childhood cancer. The main pathway from self-efficacy to HRQoL is thought to be via the emotional aspect of cancer-related fatigue. However, unlike adult survivors of cancer, self-efficacy for young survivors may not contribute much to self-management behaviors that maintain HRQoL.

Background:Ramp lesions (RLs), associated with anterior cruciate ligament (ACL) injuries, should be repaired to ensure postoperative knee stability. However, it is difficult to identify all RLs before surgery using conventional sagittal magnetic resonance (MR) images and arthroscopy from the anterior, medial, and lateral portals that are usually used during ACL reconstruction. We report the effectiveness of axial images for detecting RL.Methods:From January 2018, a total of 316 knees underwent primary ACL reconstruction with preoperative magnetic resonance imaging (MRI) examination at our hospital. Among these, 149 knees, which required meniscal suturing at the same time, were retrospectively investigated. This study evaluated 22 knees with confirmed RLs around the posterior horn of the medial meniscus. The effectiveness of the preoperative sagittal and axial MR images for detecting RL was assessed. With the MR image, a three-dimensional double-echo steady-state image with a flip angle of 25° was reconstructed into the sagittal and axial planes, respectively. Reconstructed images with 3-mm slices for sagittal slices and 1-mm slices for axial sections were used. The diagnosis was made based on the presence of RL (RL was present, RL may be present, and RL was not present) by four knee surgeons with more than 10 years of experience.Results:Approximately 53% of knee cases were diagnosed with RLs using sagittal images. Meanwhile, a diagnosis was achieved using axial images in 89% of cases.Conclusion:Axial MRI may be superior in detecting RLs.

Abstract Background: T-cell acute lymphoblastic leukemia (T-ALL) accounts for approximately 10-15% or 25% of cases of pediatric or adolescent and young adult (AYA) ALL, respectively. The use of pediatric protocols can improve outcomes in AYA T-ALL. Furthermore, nelarabine (NEL) has been shown to be effective for patients with relapsed or refractory T-ALL. This nationwide, multicenter, prospective, phase II trial for T-ALL was conducted to assess the feasibility and efficacy of NEL, intensive L-asparaginase (L-asp), and protracted intrathecal therapy (IT) when incorporated in the AIEOP-BFM-ALL 2000 based pediatric treatment for patients <25 years old at diagnosis. Patients & Methods: From December 2011 to November 2017, 364 patients with newly diagnosed T-ALL, age 0-24 (median 9.6 years), were enrolled in the JPLSG ALL-T11/JALSG T-ALL-211-U (ALL-T11) trial conducted by the Japanese Pediatric Leukemia/Lymphoma Study Group and the Japan Adult Leukemia Study Group. Patients were stratified into three groups according to their prednisone (PSL) response, initial central nervous system (CNS) status, and PCR-based minimal residual disease (MRD) at the end of induction consolidation protocol IB (TP2). Good or poor PSL responses were defined as <1.0 × 10 9/L or ≥1.0 × 10 9/L blasts in peripheral blood at day 8 following a 7-day PSL pre-phase plus one IT dose of methotrexate, respectively. Patients with good PSL response, TP2 MRD < 10 −3 and no CNS involvement, were assigned to the standard risk (SR) group, while patients with TP2 MRD ≥ 10 −3 or no complete remission (CR) after induction therapy IA were assigned to the very high risk (VHR) group. The patients who did not fulfill SR and VHR criteria were assigned to the high risk (HR) group. If TP2 MRD evaluation was not applicable, patients were classified as MRD < 10 −3. ALL-T11 was characterized by dexamethasone in IA, the additional use of E. coli derived L-asp (5000 U/m 2 × 8 in IB, 10,000 U/m 2 × 4 in reinduction protocol IIB for SR and HR groups, and 12,500 U/m 2 × 4 in protocol M for SR), incorporation of NEL (5-day course of 650 mg/m 2/day) in HR or VHR groups (6 or 1-2 courses, respectively), and elimination of prophylactic cranial radiotherapy (CRT). CRT was limited to patients with initial CNS involvement (CNS3), and the other patients received protracted IT during each treatment phase including the maintenance phase. Only VHR patients were scheduled to receive hematopoietic stem cell transplantation (HSCT) after being randomized to receive one of two arms of distinct block therapies. Results: Fifteen patients were excluded having not meeting inclusion criteria. Of 349 evaluable patients, 238 (68.2%) were male, the median white blood cell count was 45 × 10 9/L (range 0.4-1375), and 73.4% were HR by NCI criteria. Twenty-eight patients (8.0%) had CNS3 status. PCR-MRD could be evaluated in 208 patients. Among 310 stratified patients, 168 (54.2%), 103 (33.2%), and 39 (12.6%) were SR, HR, and VHR, respectively. HSCT was performed in 35 patients (10.0%). The composite CR (CR+CR in suppression) rate after IA, and the CR rate after IB were 85.4% and 90.5%, respectively. With a median follow-up of 5 years 2 months, the 3-year event-free survival (EFS) and overall survival (OS) of the whole cohort was 85.6% (95% CI: 81.5-89.9) and 91.4% (87.9-93.9), respectively (Figure 1), and the 3-year cumulative incidence of relapse was 8.9% (5.9-12.1). Induction death was seen in 14 patients (4.0%), and 3-year non-relapse mortality of the whole cohort was 0.6% (0.1-2.1). Three-year EFS and OS for each risk group were 90.4% (84.9-94.0) and 95.8% (91.4-98.0) in SR, 91.3% (83.9-95.4) and 95.1% (88.6-97.9) in HR, and 87.2% (71.9-94.5) and 87.2% (71.9-94.5) in VHR respectively. Three-year EFS and OS were 90.1% (86.1-93.0) and 95.7% (92.7-97.5), and 55.6% (30.5-74.8) and 66.7% (40.4-83.4) in MRD-negative and MRD-positive patients (p < 0.001 and p < 0.001), respectively. Grade 3 or higher peripheral motor and sensory neuropathies were seen in 9 (8.7%) and 6 (5.8%) in HR and 2 (5.1%) and 0 in VHR, respectively. Clinical allergic reaction, anaphylaxis, and pancreatitis were reported in 10 (2.9%), 16 (4.6%), and 31 (8.9%) patients, respectively. Conclusions: The addition of NEL, intensified L-asp, and protracted IT in AIEOP-BFM-ALL 2000 based treatment showed encouraging outcomes with acceptable toxicities despite the limited use of CRT and HSCT. Figure 1 Figure 1. Disclosures Hatta: Bristol-Myers Squibb: Honoraria; Novartis KK: Honoraria; Pfizer Japan Inc.: Honoraria; Otsuka Pharmaceutical.: Honoraria. Imai: Juno Therapeutics: Patents & Royalties: chimeric receptor with 4-1BB signaling domain. Saito: Toshiba corporation: Research Funding. Kiyoi: Astellas: Honoraria; celgene: Honoraria; Daiichi Sankyo: Honoraria; Dainippon Sumitomo: Honoraria; Eisai: Honoraria; Fijifilm: Honoraria; Kyowa Kirin: Honoraria; Otsuka: Honoraria; Perseus Proteomics: Honoraria; Pfizer: Honoraria; Pfizer: Honoraria; Sanofi: Honoraria; Takeda: Honoraria; Zenyaku Kogyo: Honoraria. Matsumura: Nippon Shinyaku: Research Funding; Ono: Research Funding; Bristol-Myers Squibb: Speakers Bureau; Daiichi Sankyo: Research Funding, Speakers Bureau; Pfizer: Research Funding, Speakers Bureau; Novartis: Research Funding, Speakers Bureau; Chugai: Research Funding; Asahi Kasei: Research Funding; Japan Blood Products Organization: Research Funding; Mundipharma: Research Funding; Amgen: Speakers Bureau; AYUMI Pharmaceutical: Research Funding; Eli Lilly Japan: Research Funding; Sumitomo Dainippon: Research Funding; Takeda: Research Funding; Astellas: Speakers Bureau; Kyowa Kirin: Research Funding; Taiho: Research Funding; Nihon Pharmaceutical: Research Funding; Janssen: Speakers Bureau; Mitsubishi Tanabe: Research Funding; Eisai: Research Funding; Otsuka: Consultancy, Research Funding, Speakers Bureau; MSD: Research Funding; Shionogi: Research Funding; Addvie: Research Funding. Miyazaki: Chugai: Honoraria; Kyowa-Kirin: Honoraria; Astellas: Honoraria; Novartis: Honoraria; Abbvie: Honoraria; Sumitomo-Dainippon: Honoraria, Research Funding; Daiichi-Sankyo: Honoraria; Eisai: Honoraria; Janssen: Honoraria; Pfizer: Honoraria; Bristol-Myers Squibb: Honoraria; Nippon-Shinyaku: Honoraria; Takeda: Honoraria; Sanofi: Honoraria.

Induction deaths (ID) remain a critical issue in the treatment of pediatric patients with acute lymphoblastic leukemia (ALL). The reported rate of ID in this population is 1% or higher. We speculate that this proportion might be lower in Japan because of mandatory hospitalization during induction therapy to manage complications. We retrospectively analyzed the incidence of ID among children with ALL enrolled in 4 Japanese study groups between 1994 and 2013. Among 5620 children, 41 (0.73%) cases of ID were noted. The median age was 6.5 years; 24 children were female, and 7 had T-cell ALL. Infection was the most common cause of ID (n=22), but the incidence (0.39%) was lower than that reported in western countries. Mortality within 48 hours from the onset of infection was low, comprising 25% of infection-related deaths. The incidence of infections caused by Bacillus species was low. Only 1 patient died because of Aspergillus infection. Fatal infections mostly occurred during the third week of induction therapy. Our findings suggest that close monitoring, stringent infection control, and immediate administration of appropriate antibiotics through hospitalization might be important strategies in reducing the rate of infection-related ID in pediatric patients with ALL.

Background Rearrangements of chromosome 8q24/MYC (8q24/MYC-r), resulting from t(8;14)(q24;q32), t(2;8)(p11;q24), or t(8;22)(q24;q11), are mainly associated with Burkitt lymphoma/leukemia (BL) and rarely observed in patients with B-cell precursor acute lymphoblastic leukemia (BCP-ALL). The characteristics of BCP-ALL with 8q24/MYC-r are poorly understood. Procedure A retrospective nationwide study of data from patients with pediatric BCP-ALL with 8q24/MYC-r in Japan was conducted to clarify the clinical and biological characteristics associated with 8q24/MYC-r BCP-ALL. Results Ten patients with BCP-ALL with 8q24/MYC-r, including three with double-hit leukemia (DHL) (two with t(8;14)(q24;q32) and t(14;18)(q32;q21) and one with t(8;14) and t(3;22)(q27;q11)), were identified. Patients with BCP-ALL with 8q24/MYC-r had higher median age and uric acid and lactate dehydrogenase levels, than those without 8q24/MYC-r. All patients were initially treated with ALL-type chemotherapy; however, four, including one with DHL, were switched to BL-type chemotherapy, based on cytogenetic findings. One patient relapsed after standard-risk ALL-type chemotherapy, and two patients with DHL did not attain complete remission with chemotherapy; all three died within 11 months. The other seven patients treated with BL-type or high-risk ALL-type chemotherapy are alive without disease. Conclusions The clinical and laboratory features of BL with IG-MYC rearrangement, displaying a BCP immunophenotype (Wagener et al. and Herbrueggen et al. termed it as pre-BLL), are similar to those of BCP-ALL with 8q24/MYC-r. Low-risk ALL-type chemotherapy may not be appropriate for them, and further studies are required to establish an adequate therapeutic strategy. Further studies of DHL to identify new treatment strategies are also needed.

Objective To analyse location and frequency, and change over time, of radiolucent lines (RLLs) around trabecular metal tibial components in total knee arthroplasty (TKA). Methods Osteoarthritic knees in patients who had undergone TKA were retrospectively evaluated via analysis of RLLs on anteroposterior and lateral X-rays obtained at 2 and 6 months, and 1, 2 and 3 years following TKA. Results In 125 osteoarthritic knees from 90 patients (mean age, 75.0 ± 6.2; 21 male/69 female), frequency of RLLs around trabecular metal tibial components was generally highest at 2 and 6 months, and 1 year following TKA, then gradually decreased over the 3-year follow-up. Frequency of RLLs around trabecular metal tibial components was greater at the tip of the two pegs, particularly the medial peg, and around the pegs, versus other zones. No postoperative revisions were performed for loosening. Conclusions Over 3 years following TKA, RLLs were most frequently observed up to 1 year, then gradually decreased. RLLs were significantly more frequent in the medial peg zone and zones close to the medial peg than in other zones.

Juvenile myelomonocytic leukemia (JMML), a rare and aggressive myelodysplastic/myeloproliferative neoplasm that occurs in infants and during early childhood, is characterized by excessive myelomonocytic cell proliferation. More than 80% of patients harbor germ line and somatic mutations in RAS pathway genes (eg, PTPN11, NF1, NRAS, KRAS, and CBL), and previous studies have identified several biomarkers associated with poor prognosis. However, the molecular pathogenesis of 10% to 20% of patients and the relationships among these biomarkers have not been well defined. To address these issues, we performed an integrated molecular analysis of samples from 150 JMML patients. RNA-sequencing identified ALK/ROS1 tyrosine kinase fusions (DCTN1-ALK, RANBP2-ALK, and TBL1XR1-ROS1) in 3 of 16 patients (18%) who lacked canonical RAS pathway mutations. Crizotinib, an ALK/ROS1 inhibitor, markedly suppressed ALK/ROS1 fusion-positive JMML cell proliferation in vitro. Therefore, we administered crizotinib to a chemotherapy-resistant patient with the RANBP2-ALK fusion who subsequently achieved complete molecular remission. In addition, crizotinib also suppressed proliferation of JMML cells with canonical RAS pathway mutations. Genome-wide methylation analysis identified a hypermethylation profile resembling that of acute myeloid leukemia (AML), which correlated significantly with genetic markers with poor outcomes such as PTPN11/NF1 gene mutations, 2 or more genetic mutations, an AML-type expression profile, and LIN28B expression. In summary, we identified recurrent activated ALK/ROS1 fusions in JMML patients without canonical RAS pathway gene mutations and revealed the relationships among biomarkers for JMML. Crizotinib is a promising candidate drug for the treatment of JMML, particularly in patients with ALK/ROS1 fusions.

Background: An increased perioperative complication rate has been a concern with one-stage bilateral total knee arthroplasty (TKA). The purpose of this study was to retrospectively investigate the perioperative safety and clinical results of one-stage bilateral TKA in selected low-risk patients. Methods: Sixty-seven patients who received one-stage bilateral TKAs for osteoarthritis who were American Society of Anesthesiology (ASA) class 1 or 2 were included in this study. Perioperative complications, blood loss, transfusion rate, blood laboratory results, and clinical results were evaluated up to 1 year after surgery. Results: No major complications (deep infection, pulmonary embolism, cerebrovascular accident, myocardial infarction, death, or removal or revision of the implants) were observed. The average total blood loss was 1139.5 ml. The transfusion rate was 95.5%. Postoperative hemoglobin level and C-reactive protein level gradually improved up to postoperative day 21 (P < 0.01). Bilateral knee extension knee angles and clinical scores improved postoperatively as compared with preoperative values (P < 0.01). Conclusions: Although total blood loss and transfusion rate can be high, this preliminary case series suggested that the one-stage bilateral TKA in ASA class 1 or 2 patients can have high perioperative safety levels, and good clinical results can be obtained up to 1 year after surgery. If low-risk patients are selected for bilateral TKA, a one-stage procedure can be beneficial for patients, with a minimal increase in the risk of complications.

[Purpose] The purpose of this study was to investigate factors influencing the period from surgery to discharge in patients with femoral trochanteric fractures. [Subjects and Methods] Sixty patients with femoral trochanteric fractures were investigated retrospectively. Based on the mean period from surgery to discharge (85.6 ± 26.6 days), the patients were divided into two groups: an under-85-day group (range, 29-78 days) and an over-85-day group (87-128 days). Age, gender, fracture type, presence of lesser trochanteric displacement, discharge destination, and walking ability were investigated. The relationship between these factors and the period from surgery to discharge was analyzed with logistic regression analysis. [Results] Age and lesser trochanteric displacement were significantly higher in the over-85-day group, and walking ability before fracture and at discharge were significantly lower in the over-85-day group. Logistic regression analysis showed that lesser trochanteric displacement and age were predictors of the length from surgery to discharge. Lesser trochanteric displacement were observed in 87.5% of these. Immediate displacement after surgery occurred in 57.8% of lesser trochanteric fractures, while 26.3% displaced 1 to 3 weeks after surgery. [Conclusion] This study revealed that lesser trochanteric displacement, higher age, and lower walking ability before fracture and at discharge were associated with longer hospitalizations in patients with femoral trochanteric fractures. Lesser trochanteric displacement were observed in 87.5% of lesser trochanteric fractures. These displacements occurred within 3 weeks after surgery in 84.1% of cases.

This study enrolled 49 patients with de novo childhood acute lymphoblastic leukemia (ALL) and 19 adult patients with ALL. WT1 mRNA showed high positive expression rates of 90% or more in ALL patients, and fusion gene transcripts were detected in 22.4% of childhood ALL cases prior to treatment. During follow-up at 4-6 months, WT1 mRNA levels in childhood ALL cases were observed to be lower in patients undergoing hematological remission after treatment when compared to the initial stages. We also assessed hematological remission via ROC analysis. The upper cut-off values were calculated to be 220 and 1,820 copies/μg RNA in the peripheral blood (PB) and bone marrow (BM) samples, respectively. Since 50 copies/μg RNA was determined to be both, the limit of detection (LOD) and minimal residual disease (MRD) threshold, WT1 mRNA regions below the upper cut-off values indicated remission depth. The detection of high WT1 mRNA levels, even in patients without fusion gene transcripts, reflected the treatment effects and remission depth, demonstrating its capacity to be a useful MRD monitoring marker in ALL.