Ruxolitinib in treatment-naive or corticosteroid-refractory paediatric patients with chronic graft-versus-host disease (REACH5): interim analysis of a single-arm, multicentre, phase 2 study.

BACKGROUND: Chronic graft-versus-host disease (GVHD) is a debilitating, and sometimes life threatening, complication of allogeneic haematopoietic stem-cell transplantation (HSCT). We aimed to investigate the activity, pharmacokinetics, and safety of ruxolitinib added to corticosteroids in paediatric patients (ie, <18 years) with moderate-to-severe chronic GVHD. METHODS: In this single-arm, phase 2 study, patients were recruited at 21 hospitals or clinics across 14 countries in Asia, Europe, and Canada. Eligible patients were aged 28 days to younger than 18 years, had undergone allogenic HSCT, and had been diagnosed with treatment-naive or corticosteroid-refractory moderate-to-severe chronic GVHD, per 2014 National Institutes of Health consensus criteria. Patients received oral ruxolitinib dosing on the basis of their age at the start of treatment: those aged 12 years to younger than 18 years received 10 mg twice daily (age ≥12 to <18 years group), those aged 6 years to younger than 12 years (age ≥6 to <12 years group) received 5 mg twice daily, and those aged 2 years to younger than 6 years received 4 mg/m2 twice daily (age ≥2 to <6 years group). Treatment was to be administered in 28-day cycles for approximately 36 months, alongside supportive treatment per institutional guidelines. The primary activity endpoint was overall response rate at cycle 7 day 1. Activity and safety analyses are reported in the full analysis set, which included all patients who received at least one dose of ruxolitinib. Here we report the prespecified interim analysis, scheduled to occur after all patients had completed 1 year of treatment or discontinued treatment, and the results for the primary endpoint evaluation reported here is to be considered final. This study is registered with ClinicalTrials.gov, NCT03774082, enrolment is complete, and the study is ongoing. FINDINGS: Between May 20, 2020, and Sept 17, 2021, 48 patients were screened, of whom 45 were enrolled and received at least one dose of study drug (median age was 11·0 years [IQR 7·2-14·3], 16 [36%] were female, 29 [64%] were male, 21 [47%] were White, one [2%] was Black or African American, 23 [51%] were Asian, 17 [38%] were treatment-naive, 28 [62%] were corticosteroid-refractory). As of data cutoff (Oct 19, 2022), after a median ruxolitinib exposure of 55·1 weeks (IQR 13·1-75·3), the overall response rate at cycle 7 day 1 was 40·0% (18 of 45; 90% CI 27·7-53·3), with responses seen in seven (41%) of 17 treatment-naive patients and 11 (39%) of 28 corticosteroid-refractory patients. The most common treatment-related adverse events of grade 3 or worse were neutropenia (eight [18%] of 45) and thrombocytopenia (six [13%]). Seven (16%) patients had grade 3 or worse serious treatment-related adverse events; the most common was hyponatraemia (two [4%] of 45). Three (7%) patients died while on-treatment (within 30 days of treatment discontinuation), one due to Aspergillus infection, one due to septic shock, and one due to acute respiratory distress syndrome; none were considered to be related to study drug. INTERPRETATION: Pending final analysis, this study suggests that ruxolitinib is active and well tolerated in both treatment-naive and corticosteroid-refractory patients aged 2 years to younger than 18 years with chronic GVHD, thereby supporting its use in this patient population. The safety profile of ruxolitinib in this patient population is consistent with that of adults. Final analysis of this study will provide further information on the long-term benefits of ruxolitinib in children with chronic GVHD. FUNDING: Novartis.

Advancements in the understanding and management of histiocytic neoplasms.

Histiocytic neoplasms are rare diseases involving macrophages, dendritic cells, and monocytes. They include Langerhans cell histiocytosis (LCH), Erdheim-Chester disease (ECD), Rosai-Dorfman disease (RDD), juvenile xanthogranuloma (JXG), and histiocytic sarcoma. Histiocytic neoplasms are characterized by varied clinical courses and prognoses, necessitating a nuanced understanding of their classification, epidemiology, and clinical manifestations. Genetic studies have revealed somatic mutations, predominantly in the MAPK pathway, suggesting a clonal neoplastic nature. This review covers the current understanding of histiocytic neoplasms, molecular pathophysiology, with a particular focus on mutations in genes such as BRAF, MAP2K1, and the PI3K-AKT signaling pathways, and evolving treatment strategies, especially focusing on LCH, ECD, RDD, and JXG. The treatment landscape has evolved with advancements in targeted therapies. BRAF inhibitors, such as vemurafenib and dabrafenib, have shown efficacy, especially in high-risk LCH cases; however, challenges remain, including relapse post-treatment discontinuation, and adverse effects. MEK inhibitors have also demonstrated effectiveness, and cobimetinib has recently been approved for use in adults. Further research is required to determine the optimal treatment duration and strategies for managing therapy interruptions. Advancements in molecular genetics and targeted therapies have revolutionized the management of histiocytic neoplasms. However, ongoing research is crucial for optimizing patient outcomes.

Local control and toxicity outcomes following consolidative radiation therapy in patients with high-risk neuroblastoma: a 20-year experience at a single center.

BACKGROUND: Intensive multimodal treatment can improve survival in patients with high-risk neuroblastoma, and consolidative radiation therapy has contributed to local control. We examined the clinical outcomes of patients who underwent consolidative radiation therapy at our institution. METHODS: We retrospectively reviewed the records of patients with high-risk neuroblastoma who underwent consolidative radiation therapy from March 2001 to March 2021 at Asan Medical Center. Patients underwent multimodal treatment including high-dose chemotherapy, surgery, stem cell transplantation, and maintenance therapy. Radiation (median, 21.0 Gy; range, 14-36) was administered to the primary site and surrounding lymph nodes. RESULTS: This study included 37 patients, and the median age at diagnosis was 2.8 years (range, 1.3-10.0). Four patients exhibited local failure, and 5-year free-from locoregional failure rate was 88.7%, with a median followup period of 5.7 years. The 5-year disease-free survival (DFS) and overall survival (OS) rates were 59.1% and 83.6%, respectively. Univariate analysis revealed that patients with neuron-specific enolase levels > 100 ng/mL had significantly worse DFS and OS (P = 0.036, 0.048), and patients with no residual disease before radiation therapy showed superior OS (P = 0.029). Furthermore, patients with 11q deletion or 17q gain exhibited poor DFS and OS, respectively (P = 0.021, 0.011). Six patients experienced grade 1 acute toxicity. Late toxicity was confirmed in children with long-term survival, predominantly hypothyroidism and hypogonadism, typically < grade 3, possibly attributed to combination treatment. Four patients experienced late toxicity ≥ grade 3 with chronic kidney disease, growth hormone abnormality, ileus, premature epiphyseal closure, and secondary tumor, and recovered by hospitalization or surgical treatment. CONCLUSIONS: In patients with high-risk neuroblastoma, consolidative radiotherapy to the primary tumor site resulted in excellent local control and a tolerable safety profile.

Long-term endocrine sequelae after hematopoietic stem cell transplantation in children and adolescents.

PURPOSE: As the survival rate from pediatric cancers has increased significantly with advances in treatment modalities, long-term endocrine complications have also risen. This study investigated the frequencies and risks of endocrine sequelae in childhood cancer survivors who received hematopoietic stem cell transplantation (HSCT). METHODS: This study included 200 pediatric patients who underwent HSCT. Clinical and endocrinological findings were collected retrospectively. The median follow-up duration after HSCT was 14 years. RESULTS: Endocrine complications occurred in 135 patients (67.5%). Children who underwent HSCT at pubertal age (n=100) were at higher risk of endocrine complications than those who received it at prepubertal age (79% vs. 56%, P=0.001). The most common complication was hypogonadism (40%), followed by dyslipidemia (22%). Short stature and diabetes mellitus were more prevalent in the prepubertal group, whereas hypogonadism and osteoporosis were more common in the pubertal group. Being female, pubertal age at HSCT, and glucocorticoid use were predictors of an increased risk for any complication. Radiation exposure increased the risk of short stature and hypothyroidism. Hypogonadism was significantly associated with being female, pubertal age at HSCT, and high-dose radiation. Pubertal age at HSCT also increased the risks of osteoporosis and dyslipidemia. CONCLUSION: This study demonstrates that long-term endocrine complications are common after HSCT in children and adolescents. Age at HSCT is a critical factor for endocrine complications after HSCT. These findings suggest that surveillance strategies for endocrine complications in childhood cancer survivors should be specified according to age at HSCT.

Ten-Year Trends of Hematopoietic Stem Cell Transplantation in Korean Pediatric Cancer from the National Health Insurance Claims Data.

PURPOSE: We aimed to determine the current application and survival trends of hematopoietic stem cell transplantation (HSCT) among Korean children and adolescents with cancer. MATERIALS AND METHODS: Data of patients aged < 20 years with KCD-10 (Korean Classifications of Diseases, 10th revision) C codes and specific designation codes were collected from the National Health Insurance Service database. Thirty claim codes for HSCT were included, and data from 2009 to 2019 were analyzed. RESULTS: The operational definition of pediatric cancer yielded an annual average of 2,000, with annual cases decreasing. In 2019, 221 HSCTs were performed, a decrease from the ten-year average of 276. Allografts outnumbered autografts with a ratio of 1.5:1. The source of allograft was bone marrow in 15% of patients in 2009; however, it substantially decreased to 3.3% in 2019. Furthermore, 70.5% of allogeneic HSCT used peripheral blood stem cell (PBSC) grafts, which increased to 89.3% by 2015. Cord blood utilization markedly decreased to 2.7% in 2018. The 5-year overall survival (OS) rate of all patients was 85.1%. Overall mortality decreased among patients who underwent recent HSCT, and they exhibited a higher 5-year OS rate. CONCLUSION: In Korea, the number of pediatric patients with cancer is declining; however, the ratio of transplants to all patients remains constant. Patients who recently underwent transplantation showed better survival rates, possibly due to HSCT optimization. Korea showed a substantially greater PBSC utilization in pediatric HSCT. An in-depth examination encompassing donor relations and cause of death with a prospective registry is required in future studies.

Increased PD-1 expression of bone marrow T-cells in acute myeloid leukaemia patients after stem cell transplantation, and its association with overall survival.

BACKGROUND: Immune checkpoints are involved in mechanisms by which tumours escape from the host immune system. Our aim was to evaluate acute myeloid leukaemia (AML) patients to determine expression levels of checkpoint molecules according to diagnosis and treatments, and to identify optimal candidates for checkpoint blockade. METHODS: Bone marrow (BM) samples were obtained from 279 AML patients at different disease status and from 23 controls. Flow cytometric analyses of PD-1 and PD-L1/PD-L2 expression were performed. RESULTS: Programmed death-1 (PD-1) expression levels on CD8+ T-cells at AML diagnosis were increased compared to controls. PD-L1 and PD-L2 expression levels on leukaemic cells at diagnosis were significantly higher in secondary AML than in de novo AML. PD-1 levels on CD8+ and CD4+ T-cells after allo-SCT were significantly higher than those at diagnosis and after CTx. PD-1 expression on CD8+ T-cells increased in the acute GVHD group than in the non-GVHD group. The overall survival of patients with high PD-1 expression on CD8+ T-cells was significantly shorter than that of patients with low PD-1 expression. CONCLUSIONS: In conclusion, patients who underwent allo-SCT exhibited high PD-1 expression, suggesting that allo-SCT increases PD-1 expression on T-cells, and the patients with high PD-1 expression on CD8+ T-cells after allo-SCT showed the poor prognosis. For these patients, PD-1 blockade could be an immunotherapeutic strategy.

Correction: Immunologic monitoring of cytomegalovirus (CMV) enzyme-linked immune absorbent spot (ELISPOT) for controlling clinically significant CMV infection in pediatric allogeneic hematopoietic stem cell transplant recipients.

[This corrects the article DOI: 10.1371/journal.pone.0246191.].

CD19/CD22 bispecific chimeric antigen receptor­NK­92 cells are developed and evaluated.

Anti-CD19 chimeric antigen receptor (CAR)-T cells have improved the outcomes of patients with B cell leukemia and lymphoma. However, their applications and positive outcomes remain limited. CAR-T cells are currently restricted to autologous blood as their source and their use can lead to downregulation of CD19 expression along with complications such as graft-versus-host disease and cytokine release syndrome. The present study aimed to develop anti-CD19/CD22 bispecific CAR structures using an anti-CD22 monoclonal antibody clone from chickens and analyze them in natural killer (NK)-92 cells, a human NK cell line, in vitro and in vivo. Anti-CD19/CD22 CAR-NK-92 cell cytotoxicity was assessed by the survival of target cells and counted using flow cytometry. Anti-CD22/CD19 and loop-structured anti-CD19/CD22 bi-specific CAR-NK-92 cells showed improved efficacy against OCI-Ly7 cells, a human B cell lymphoma cell line, compared with other CAR structures. These results demonstrate the potential of anti-CD19/CD22 bispecific CAR-NK cells and suggested that optimizing CAR structures in NK cells can improve the efficacy of CAR therapy.

High-dose chemotherapy followed by autologous stem cell transplantation in pediatric patients with relapsed osteosarcoma.

BACKGROUND: Patients with relapsed osteosarcoma have poor treatment outcomes. High-dose chemotherapy with autologous stem cell transplantation (HDCT/ASCT) has been used in several high-risk malignant solid tumors; however, few studies have evaluated their role in treating osteosarcoma. We evaluated the effectiveness of HDCT/ASCT in relapsed pediatric osteosarcoma cases. PROCEDURE: We retrospectively reviewed the medical records of 40 patients diagnosed with and treated for relapsed osteosarcoma at Asan Medical Center and Samsung Medical Center from January 1996 to July 2019. RESULTS: The median age of this cohort was 13.4 years (range: 6.1-18.2). The cohort's 5-year overall survival (OS) was 51.0% ± 0.1% during a median follow-up period of 67.5 months. Twenty-five patients (62.5%) achieved complete remission (CR) with salvage treatment, and the 5-year OS was 82.4% ± 0.1%, whereas none of the remaining 15 patients who did not achieve CR survived (p < .0001). Of the 25 CR cases, 15 underwent subsequent HDCT/ASCT. We compared the effect of HDCT/ASCT among patients who achieved CR. There were no significant differences in the 5-year OS outcomes between patients who did and did not receive HDCT/ASCT (83.9% ± 0.1%, 13/15 vs. 80.0% ± 0.1%, 8/10, respectively; p = .923). CONCLUSION: To our knowledge, we report the first comparative cohort study that proved HDCT/ASCT does not significantly improve survival outcomes in relapsed osteosarcoma. Achievement of CR remains the most crucial factor for good survival outcomes.

Comorbidity Differences by Trajectory Groups as a Reference for Identifying Patients at Risk for Late Mortality in Childhood Cancer Survivors: Longitudinal National Cohort Study.

BACKGROUND: Childhood cancer has a high long-term morbidity and mortality rate. Five years after the initial cancer diagnosis, approximately two-thirds of childhood cancer survivors experience at least one late complication, with one-quarter experiencing severe, life-threatening complications. Chronic health conditions can impact survivors' life planning and daily activities, reducing their health-related quality of life. Comprehensive and longitudinal data are required for investigations of national claims data. OBJECTIVE: This study aimed to address clinical and health policy interventions and improved survival rates. A comprehensive categorization of the long-term morbidities associated with childhood cancer survivorship is required. We analyzed the trajectory groups associated with long-term mortality among childhood cancer survivors. METHODS: We collected data from a nationwide claims database of the entire Korean population. Between 2003 and 2007, patients diagnosed with and treated for cancer before the age of 20 years were included. With 8119 patients who survived >10 years, 3 trajectory groups were classified according to yearly changes in the number of diagnoses (the lowest in group 1 and the highest in group 3). RESULTS: The patterns of most comorbidities and survival rates differed significantly between the trajectory groups. Group 3 had a higher rate of mental and behavioral disorders, neoplasms, and blood organ diseases than the other two groups. Furthermore, there was a difference in the number of diagnoses by trajectory groups over the entire decade, and the disparity increased as the survival period increased. If a patient received more than four diagnoses, especially after the fourth year, the patient was likely to be assigned to group 3, which had the worst prognosis. Group 1 had the highest overall survival rate, and group 3 had the lowest (P<.001). Group 3 had the highest hazard ratio of 4.37 (95% CI 2.57-7.42; P<.001) in a multivariate analysis of late mortality. CONCLUSIONS: Our findings show that the pattern of comorbidities differed significantly among trajectory groups for late death, which could help physicians identify childhood cancer survivors at risk for late mortality. Patients with neoplasms, blood organ diseases, or mental and behavioral disorders should be identified as having an increased risk of late mortality. Furthermore, vigilance and prompt action are essential to mitigate the potential consequences of a child cancer survivor receiving four or more diagnoses within a year.

Epidemiologic and Clinical Outcomes of Pediatric Renal Tumors in Korea: A Retrospective Analysis of The Korean Pediatric Hematology and Oncology Group (KPHOG) Data.

PURPOSE: Renal tumors account for approximately 7% of all childhood cancers. These include Wilms tumor (WT), clear cell sarcoma of the kidney (CCSK), malignant rhabdoid tumor of the kidney (MRTK), renal cell carcinoma (RCC), congenital mesoblastic nephroma (CMN) and other rare tumors. We investigated the epidemiology of pediatric renal tumors in Korea. MATERIALS AND METHODS: From January 2001 to December 2015, data of pediatric patients (0-18 years) newly-diagnosed with renal tumors at 26 hospitals were retrospectively analyzed. RESULTS: Among 439 patients (male, 240), the most common tumor was WT (n=342, 77.9%), followed by RCC (n=36, 8.2%), CCSK (n=24, 5.5%), MRTK (n=16, 3.6%), CMN (n=12, 2.7%), and others (n=9, 2.1%). Median age at diagnosis was 27.1 months (range 0-225.5) and median follow-up duration was 88.5 months (range 0-211.6). Overall, 32 patients died, of whom 17, 11, 1, and 3 died of relapse, progressive disease, second malignant neoplasm, and treatment-related mortality. Five-year overall survival and event free survival were 97.2% and 84.8% in WT, 90.6% and 82.1% in RCC, 81.1% and 63.6% in CCSK, 60.3% and 56.2% in MRTK, and 100% and 91.7% in CMN, respectively (p < 0.001). CONCLUSION: The pediatric renal tumor types in Korea are similar to those previously reported in other countries. WT accounted for a large proportion and survival was excellent. Non-Wilms renal tumors included a variety of tumors and showed inferior outcome, especially MRTK. Further efforts are necessary to optimize the treatment and analyze the genetic characteristics of pediatric renal tumors in Korea.

Outcomes of intracranial non-germinomatous germ cell tumors: a retrospective Asian multinational study on treatment strategies and prognostic factors.

PURPOSE: Non-germinomatous germ cell tumors (NGGCTs) are rare pediatric conditions. This multicenter study using Asian multinational patient data investigated treatment outcomes and prognostic factors for NGGCTs. METHODS: Medical records of 251 patients with NGGCTs treated from 1995 to 2015 were retrospectively analyzed from participating centers in Asian countries (Korea, Taiwan, Singapore, and Japan). RESULTS: The median follow up was 8.5 years (95% CI 7.8-9.9). In the total cohort, 5-year event-free survival (EFS) and overall survival (OS) rates were 78.2% and 85.4%, respectively. In 17.9% of the patients, diagnosis was determined by tumor markers alone (alpha-fetoprotein ≥ 10 ng/mL (Korea) or > 25 ng/mL (Taiwan and Singapore), and/or ß-human chorionic gonadotropin (ß-hCG) ≥ 50 mIU/mL). Patients with immature teratomas and mature teratomas comprised 12.0% and 8.4%, respectively. The 5-year EFS rate was higher in patients with histologically confirmed germinoma with elevated ß-hCG (n = 28) than those in patients with malignant NGGCTs (n = 127). Among malignant NGGCTs, patients with choriocarcinoma showed the highest 5-year OS of 87.6%, while yolk sac tumors showed the lowest OS (68.8%). For malignant NGGCT subgroups, an increase in serum ß-hCG levels by 100 mIU/mL was identified as a significant prognostic factor associated with the EFS and OS. CONCLUSION: Our result shows excellent survival outcomes of overall CNS NGGCT. However, treatment outcome varied widely across the histopathologic subgroup of NGGCT. Hence, this study suggests the necessity for accurate diagnosis by surgical biopsy and further optimization of diagnosis and treatment according to the histopathology of NGGCTs. Future clinical trials should be designed for individualized treatments for different NGGCTs subsets.

Favorable outcomes with durable chimerism after hematopoietic cell transplantation using busulfan and fludarabine-based reduced-intensity conditioning for pediatric patients with hemophagocytic lymphohistiocytosis.

Background: The incorporation of a reduced-intensity conditioning (RIC) regimen in hematopoietic cell transplantation (HCT) for patients with hemophagocytic lymphohistiocytosis (HLH) has decreased early mortality but is associated with a high rate of mixed chimerism and graft failure. Here, we present a successful single-center experience using busulfan and a fludarabine-based RIC regimen for the treatment of HLH. Methods: The medical records of pediatric patients with HLH who underwent HCT using a busulfan/ fludarabine-based RIC regimen between January 2008 and December 2017 were reviewed retrospectively. Results: Nine patients received HCT with a busulfan/fludarabine-based RIC regimen. Three patients had primary HLH, and the other six patients had secondary HLH with multiple reactivations. All three patients with primary HLH had UNC13D mutations. All patients achieved neutrophil and platelet engraftment at a median of 11 days (range, 10‒21) and 19 days (range, 13‒32), and all eight evaluable patients had sustained complete donor chimerism at the last follow-up. Two patients (22%) experienced grade 2 acute graft-versus- host disease (GVHD). Two patients (22%) developed chronic GVHD, and one died from chronic GVHD. One patient (11%) experienced reactivation 4 months after HCT from a syngeneic donor and died of the disease. The 8-year overall survival and event-free survival rates were 78%. No early treatment-related mortality within 100 days after HCT was observed. Conclusion: Our experience suggests that a busulfan/fludarabine-based RIC regimen is a viable option for pediatric patients with HLH who require HCT.

Clinical characteristics and treatment outcomes of children and adolescents with aggressive mature B-cell lymphoma: a single-center analysis.

Background: Aggressive mature B-cell non-Hodgkin lymphoma (B-NHL) is the most common non-Hodgkin lymphoma in children. The outcome of chemotherapy for B-NHL has improved over decades. Methods: We reviewed 82 children and adolescents with B-NHL diagnosed at Asan Medical Center between 1993 and 2020. The D-COMP/COMP (daunomycin-cyclophosphamide, doxorubicin, vincristine, and prednisolone), Pediatric Oncology Group (POG)-9219/9315/9317, R-CHOP/CHOP (rituximab-cyclophosphamide, doxorubicin, vincristine, and prednisolone), and Lymphomes Malins B 89 (LMB89)/LMB96 regimens were administered. In 2018, rituximab was added to the LMB protocol (R-LMB) for advanced-staged Burkitt lymphoma (BL). The patients' clinical features and treatment outcomes were retrospectively analyzed. Results: The most common subtype was BL (61%), followed by diffuse large B-cell lymphoma (DLBCL) (35%). The median age was 7.8 (range, 1.3‒16.4) years, and the most frequently used regimen was French‒American‒British (FAB)/LMB96 (58 patients, 70.7%). The 5-year overall survival (OS) and event-free survival (EFS) rates were 92.5% and 85.7%, respectively. The EFS rates of patients with BL and DLBCL were 90.0% and 79.3%, respectively. Among the FAB/LMB risk groups, group C (85.7%) had a significantly lower 5-year OS (P =0.037). Eleven events occurred (6 relapses, 3 deaths, and 2 secondary malignancies) during the median follow-up of 7.1 (range, 3.7‒118.5) months. Two patients treated with R-LMB had good outcomes without complications. Conclusion: Various treatment regimens have favorable outcomes in pediatric patients with B-NHL. However, further studies are needed to improve survival in high-risk patients. In addition, careful monitoring for acute toxicity or secondary malignancy due to intensive multidrug chemotherapy is required.

Clinical and genetic features of four patients with Pearson syndrome: An observational study.

ABSTRACT: Pearson syndrome (PS) is a multisystem mitochondrial cytopathy arising from deletions in mitochondrial DNA. Pearson syndrome is a sporadic disease that affects the hematopoietic system, pancreas, eyes, liver, and heart and the prognosis is poor. Causes of morbidity include metabolic crisis, bone marrow dysfunction, sepsis, and liver failure in early infancy or childhood. Early diagnosis may minimize complications, but suspicion of the disease is difficult and only mitochondrial DNA gene testing can identify mutations. There is no specific treatment for PS, which remains supportive care according to symptoms; however, hematopoietic stem cell transplantation may be considered in cases of bone marrow failure.We herein describe the clinical and genetic characteristics of four patients with PS. One patient presented with hypoglycemia, two developed pancytopenia, and the final patient had hypoglycemia and acute hepatitis as the primary manifestation. All patients had lactic acidosis. Additionally, all patients showed a variety of clinical features including coagulation disorder, pancreatic, adrenal, and renal tubular insufficiencies. Two patients with pancytopenia died in their early childhood. Our experience expands the phenotypic spectrum associated with PS and its clinical understanding.

Clinical Characteristics and Treatment Outcomes of Childhood Acute Promyelocytic Leukemia in Korea: A Nationwide Multicenter Retrospective Study by Korean Pediatric Oncology Study Group.

PURPOSE: Acute promyelocytic leukemia (APL) is a rare disease in children and there are some different characteristics between children and adult. We aimed to evaluate incidence, clinical characteristics and treatment outcomes of pediatric APL in Korea. MATERIALS AND METHODS: Seventy-nine pediatric APL patients diagnosed from January 2009 to December 2016 in 16 tertiary medical centers in Korea were reviewed retrospectively. RESULTS: Of 801 acute myeloid leukemia children, 79 (9.9%) were diagnosed with APL. The median age at diagnosis was 10.6 years (range, 1.3 to 18.0). Male and female ratio was 1:0.93. Thirty patients (38.0%) had white blood cell (WBC) count greater than 10×109/L at diagnosis. All patients received induction therapy consisting of all-trans retinoic acid and chemotherapy. Five patients (6.6%) died during induction chemotherapy and 66 patients (86.8%) achieved complete remission (CR) after induction chemotherapy. The causes of death were three intracranial hemorrhage, one cerebral infarction, and one sepsis. Five patients (7.1%) suffered a relapse during or after maintenance chemotherapy. The estimated 4-year event-free survival and overall survival (OS) rates were 82.1%±4.4%, 89.7%±5.1%, respectively. The 4-year OS was significantly higher in patients with initial WBC < 10×109/L than in those with initial WBC ≥ 10×109/L (p=0.020). CONCLUSION: This study showed that the CR rates and survival outcomes in Korean pediatric APL patients were relatively good. The initial WBC count was the most important prognostic factor and most causes of death were related to serious bleeding in the early stage of treatment.

Outcomes of intracranial germinoma-A retrospective multinational Asian study on effect of clinical presentation and differential treatment strategies.

BACKGROUND: This multinational study was conducted to report clinical presentations and treatment strategies in patients with intracranial germinomas across selected Asian centers, including failure patterns, risk factors, and outcomes. METHODS: A retrospective data collection and analysis of these patients, treated between 1995 and 2015 from eight healthcare institutions across four countries was undertaken. RESULTS: From the results, 418 patients were analyzed, with a median follow-up of 8.9 years; 79.9% of the patients were M0, and 87.6% had ß-human chorionic gonadotropin values <50 mIU/mL. The 5/10-year overall survival (OS) and recurrence-free survival (RFS) rates were 97.2%/96.2% and 89.9%/86.9%, respectively. RFS was predicted by the radiotherapy (RT) field, with focal RT having the worst outcome, whereas chemotherapy usage had no impact on survival. Among patients who received chemotherapy, response to chemotherapy did not predict survival outcomes. In M0 patients, primary basal ganglia tumors predicted a worse RFS. In patients with bifocal tumors, an extended field RT was associated with better outcomes. In multivariable analysis, only RT fields were associated with RFS. In relapsed patients, salvage rates were high at 85.7%. Additionally, patients who received salvage RT had a better outcome (91.6% vs. 66.7%). CONCLUSIONS: Survival outcomes of patients with germinoma were excellent. Thus, the focus of treatment for intracranial germinoma should be on survivorship. Further studies are warranted to find the optimal intensity and volume of radiation, including the role of chemotherapy in the survival of patients with intracranial germinomas, considering age, primary tumor location, and extent of disease.

Case Report: Mevalonic Aciduria Complicated by Acute Myeloid Leukemia After Hematopoietic Stem Cell Transplantation.

Mevalonic aciduria (MA) is the most severe clinical subtype of mevalonate kinase deficiency (MKD) caused by an inherited defect in the mevalonate pathway. The treatment of MKD focuses on the suppression of recurrent hyperinflammatory attacks using anti-inflammatory drugs. Recently, allogeneic hematopoietic stem cell transplantation (HCT) was shown to successfully ameliorate autoinflammatory attacks in patients with MKD. Here, we report a case of an infant who showed severe recurrent systemic inflammation and was diagnosed with MA. Although she responded to steroids, her symptoms relapsed after the dose was tapered, and organ deterioration occurred. Therefore, at the age of 11 months, HCT from a matched, unrelated donor was performed for curative treatment. However, at 50 days after transplantation, acute myeloid leukemia was diagnosed, which was chemo-refractory. A second HCT from her haploidentical father was performed to treat the acute myeloid leukemia, but the patient died of sepsis on day 4 after transplantation. This is the first report of malignancy following HCT for MA. Our findings suggest that normalizing the mevalonate pathway after HCT in patients with MKD impacts patients differently depending on the clinical spectrum and severity of disease.

Characteristics of Human Peripheral Blood γδ T Cells Expanded With Zoledronate.

BACKGROUND/AIM: This study aimed to investigate the characteristics of human peripheral blood γδ T cells, which were expanded ex vivo in the presence of zoledronate (ZOL). MATERIALS AND METHODS: Human peripheral blood cells were cultured with IL-2 and IL-15 in the presence or absence of ZOL, which was added as a phospho-antigen, and their phenotypes were assessed by flow cytometry. Expanded γδ T cells were transduced with CD19 CAR vector, and the cytotoxicity was evaluated in vitro and in vivo by flow cytometry. RESULTS: Ex vivo expansion did not hamper the expression of activating receptors. Interestingly, ZOL promoted the expression of CD226 (DNAM-1), TRAIL, and FAS-L in the Vδ1 subset of γδ T cells. Expanded γδ T cells containing CD19 CAR+ γδ T cells removed B cell lymphoma cells effectively in vivo. CONCLUSION: γδ T cells could be a promising immunotherapeutic for cancer.