Assessing Long-Term Neurologic Outcomes in SAMD9L-Related Ataxia-Pancytopenia Syndrome.

BACKGROUND: Most published reports on SAMD9L-related ataxia-pancytopenia syndrome (ATXPC) have emphasized the hematologic findings. Fewer details are known about the progression of neurologic manifestations and methods for monitoring them. CASES: We present six individuals from two families transmitting a heterozygous variant in SAMD9L, exhibiting clinical variations in their hematologic and neurologic findings. Serial motor function testing was used to monitor motor proficiency over a 2 to 3 year period in the proband and his father from Family 1. CONCLUSIONS: Our case series focuses on the neurologic progression in patients with heterozygous variants in SAMD9L. Patients with ATXPC should be followed to evaluate a wide range of neurologic manifestations. Serial motor function testing using a standardized method is helpful to track changes in balance and coordination in children and adults with ATXPC and could aid in a future extended natural history study.

Epstein Barr virus-directed T-cell therapy for refractory EBV-PTLD in a toddler post Orthotopic heart transplantation.

Epstein-Barr Virus (EBV) is a ubiquitous herpes type virus that is associated with post-transplant lymphoproliferative disorder (PTLD). Usual management includes reduction or cessation of immunosuppression and in some cases chemotherapy including rituximab. However, limited therapies are available if PTLD is refractory to rituximab. Several clinical trials have investigated the use of EBV-directed T cells in rituximab-refractory patients; however, data regarding response is scarce and inconclusive. Herein, we describe a patient with EBV-PTLD refractory to rituximab after orthotopic heart transplantation (OHT) requiring EBV-directed T-cell therapy. This article aims to highlight the unique and aggressive clinical presentation and progression of PTLD with utilization of EBV-directed T-cell therapy for management and associated pitfalls.

Dasatinib with intensive chemotherapy in de novo paediatric Philadelphia chromosome-positive acute lymphoblastic leukaemia (CA180-372/COG AALL1122): a single-arm, multicentre, phase 2 trial.

BACKGROUND: The outcome of children with Philadelphia chromosome-positive (Ph-positive) acute lymphoblastic leukaemia significantly improved with the combination of imatinib and intensive chemotherapy. We aimed to investigate the efficacy of dasatinib, a second-generation ABL-class inhibitor, with intensive chemotherapy in children with newly diagnosed Ph-positive acute lymphoblastic leukaemia. METHODS: CA180-372/COG AALL1122 was a joint Children's Oncology Group (COG) and European intergroup study of post-induction treatment of Ph-positive acute lymphoblastic leukaemia (EsPhALL) open-label, single-arm, phase 2 study. Eligible patients (aged >1 year to <18 years) with newly diagnosed Ph-positive acute lymphoblastic leukaemia and performance status of at least 60% received EsPhALL chemotherapy plus dasatinib 60 mg/m2 orally once daily from day 15 of induction. Patients with minimal residual disease of at least 0·05% after induction 1B or who were positive for minimal residual disease after the three consolidation blocks were classified as high risk and allocated to receive haematopoietic stem-cell transplantation (HSCT) in first complete remission. The remaining patients were considered standard risk and received chemotherapy plus dasatinib for 2 years. The primary endpoint was the 3-year event-free survival of dasatinib plus chemotherapy compared with external historical controls. The trial was considered positive if one of the following conditions was met: superiority over chemotherapy alone in the AIEOP-BFM 2000 high-risk group; or non-inferiority (with a margin of -5%) or superiority to imatinib plus chemotherapy in the EsPhALL 2010 cohort. All participants who received at least one dose of dasatinib were included in the safety and efficacy analyses. This trial was registered with ClinicalTrials.gov, NCT01460160, and recruitment is closed. FINDINGS: Between March 13, 2012, and May 27, 2014, 109 patients were enrolled at 69 sites (including 51 COG sites in the USA, Canada, and Australia, and 18 EsPhALL sites in Italy and the UK). Three patients were ineligible and did not receive dasatinib. 106 patients were treated and included in analyses (49 [46%] female and 57 [54%] male; 85 [80%] White, 13 [12%] Black or African American, five [5%] Asian, and three [3%] other races; 24 [23%] Hispanic or Latino ethnicity). All 106 treated patients reached complete remission; 87 (82%) were classified as standard risk and 19 (18%) met HSCT criteria and were classified as high risk, but only 15 (14%) received HSCT in first complete remission. The 3-year event-free survival of dasatinib plus chemotherapy was superior to chemotherapy alone (65·5% [90% Clopper-Pearson CI 57·7 to 73·7] vs 49·2% [38·0 to 60·4]; p=0·032), and was non-inferior to imatinib plus chemotherapy (59·1% [51·8 to 66·2], 90% CI of the treatment difference: -3·3 to 17·2), but not superior to imatinib plus chemotherapy (65·5% vs 59·1%; p=0·27). The most frequent grade 3-5 adverse events were febrile neutropenia (n=93) and bacteraemia (n=21). Nine remission deaths occurred, which were due to infections (n=5), transplantation-related (n=2), due to cardiac arrest (n=1), or had an unknown cause (n=1). No dasatinib-related deaths occurred. INTERPRETATION: Dasatinib plus EsPhALL chemotherapy is safe and active in paediatric Ph-positive acute lymphoblastic leukaemia. 3-year event-free survival was similar to that of previous Ph-positive acute lymphoblastic leukaemia trials despite the limited use of HSCT in first complete remission. FUNDING: Bristol Myers Squibb.

Feasibility study of busulfan, fludarabine, and thiotepa conditioning regimen for allogeneic hematopoietic stemcell transplantationfor children and young adults with nonmalignant disorders.

BACKGROUND: Hematopoietic stem cell transplant (HSCT) is the only curative treatment for several pediatric non-malignant disorders. A widely used conditioning backbone is busulfan, fludarabine, and rabbit anti-thymocyte globulin (rATG). Thiotepa has improved engraftment when added to this regimen, however the minimum effective dose (MED) of thiotepa to achieve engraftment while minimizing toxicities has not been well established. OBJECTIVES: The primary objective of this prospective feasibility study was to determine the MED of thiotepa (5mg/kg) in combination with reduced-dose busulfan, fludarabine or cyclophosphamide, and rATG required to achieve engraftment in >90% of HSCT recipients for non-malignant disorders with acceptable toxicity. RESULTS: Six patients who received fully matched HSCT were enrolled. Patient diagnoses included Wiskott-Aldrich syndrome (n = 1), CD40L deficiency (n = 1), sickle cell disease (n = 2), autoinflammatory syndrome (n = 1), and paroxysmal nocturnal hemoglobinuria (n = 1). All six patients achieved engraftment prior to Day +42 and five patients had stable full donor engraftment. Two of the six patients (33%) developed acute GVHD and/or chronic GHVD, both of whom had sickle cell disease. At a median follow-up of 2.25 years post-transplant, all patients were alive without evidence of disease recurrence. None of the patients experienced grade 4 or 5 toxicities. Three out of six patients (50%) developed grade 3 adverse events. Neurocognitive functioning of children under 10 years of age was not adversely affected by this regimen. CONCLUSION: This approach shows acceptable toxicity and reliable engraftment in children with non-malignant disorders receiving related or unrelated HLA-matched transplants.

Trends in Pediatric Cancer Care in Florida From 1981-2020: Changing Patterns in a Growing and Increasingly Diverse Population.

Background The Florida Association of Pediatric Tumor Programs (FAPTP) has used the Statewide Patient Information Reporting System (SPIRS) since 1981 to track all new cases of pediatric cancer. We reviewed the last 40 years of data to see how pediatric cancer care has evolved. Methods We retrospectively analyzed SPIRS data from 1981 through 2020 in five-year increments, looking at numbers of new diagnoses, care delivery sites, and trial enrollment in Children's Oncology Group (COG) studies. Results From 1981-2020 Florida's population increased almost 88% while the pediatric population only grew 61%. New pediatric cancer diagnoses increased 326% to over 1,000 new cases/year. The percentage of patients treated at FAPTP centers grew from 30% to 57% with an annual percentage change (APC) of 10.3% (95% Confidence Interval [CI] of 0.6 to 20.9%). The rate of COG clinical trial enrollment decreased from 32% in 1981-1985 to 20% in 2016-2020, for an APC of 8.91% (95% CI of -13.3 to -4.3%). Conclusions The striking increase in pediatric cancer cases in Florida over the last 40 years was out of proportion to the population growth. More patients received care at FAPTP centers, but a lower percentage were enrolled on COG trials.

Volunteer-Based Social Support Structures and Program Exposure Outcomes in an Adolescent Young Adult Palliative Care Peer Support Program.

Objective: To conduct a social network analysis (SNA) of patient-volunteer networks and assess the impact of patient characteristics on network measures. Background: Volunteers play a critical role in providing peer support to adolescent and young adult (AYA) palliative care patients. Streetlight at UF Health is a peer support palliative care program for hospitalized AYAs that aims at forming positive peer relationships through volunteer visits, events, and a virtual online health community. Methods: Data were collected on patient characteristics, hospitalizations, average length of stays (LOS), and volunteer visitation records. Egocentric SNAs were conducted on each patient to calculate network outcomes. Study participants were AYA patients (N = 69), enrolled in the US-based Streetlight program at UF Health Shands Hospital. Results: The LOS was significantly associated with network size (B = 0.583; 95% confidence interval; CI [0.463 to 0.702]). Autoimmune patients had smaller network sizes when controlling for LOS. Total hospital admissions predicted - 0.172 ([- 0.263 to - 0.080]) lower average repeat visits. Higher average repeat visits were predicted for patients who had cancer (B = 0.246 [0.046 to 0.447]) and awaiting organ transplantation (B = 0.370 [0.082 to 0.658]). Although cystic fibrosis patients received more visits (B = 0.364 [0.003 to 0.724]) compared with other illness populations, the network density was lower (B = - 0.580 [1.01 to - 0.155]). Cancer patients had networks with a higher diversity in volunteer repeat visits (B = 0.714 [0.312 to 0.920]). Conclusions: Significant relationships between patient characteristics and network outcomes highlight the differences in social support service delivery among diverse populations. These analyses can be utilized in practice to guide program delivery for high-need patients.

Establishing Cost-Effective Allocation of Proton Therapy for Patients With Mediastinal Hodgkin Lymphoma.

PURPOSE: For curative treatment of Hodgkin lymphoma, radiation therapy benefit must be weighed against toxicity. Although more costly, proton radiation therapy reduces dose to healthy tissue, potentially improving the therapeutic ratio compared with photons. We sought to determine the cost-effectiveness of proton versus photon therapy for mediastinal Hodgkin lymphoma (MHL) based on reduced heart disease. METHODS AND MATERIALS: Our model approach was 2-fold: (1) Use patient-level dosimetric information for a cost-effectiveness analysis using a Markov cohort model. (2) Use population-based data to develop guidelines for policymakers to determine thresholds of proton therapy favorability for a given photon dose. The HD14 trial informed relapse risk; coronary heart disease risk was informed by the Framingham risk calculator modified by the mean heart dose (MHD) from radiation. Sensitivity analyses assessed model robustness and identified the most influential model assumptions. A 30-year-old adult with MHL was the base case using 30.6-Gy proton therapy versus photon intensity modulated radiation therapy. RESULTS: Proton therapy was not cost-effective in the base case for male ($129,000/ quality-adjusted life years [QALYs]) or female patients ($196,000/QALY). A 5-Gy MHD decrease was associated with proton therapy incremental cost-effectiveness ratio <$100,000/QALY in 40% of scenarios. The hazard ratio associating MHD and heart disease was the most influential clinical parameter. CONCLUSIONS: Proton therapy may be cost-effective a select minority of patients with MHL based on age, sex, and MHD reduction. We present guidance for clinicians using MHD to aid decision-making for radiation therapy modality.

Eating behaviors and dietary quality in childhood acute lymphoblastic leukemia survivors.

BACKGROUND: Childhood acute lymphoblastic leukemia (ALL) survivors' increased risk for adverse health outcomes could be mitigated through consuming a balanced diet. Nonetheless, >70% of adult survivors do not meet survivorship dietary recommendations. ALL treatment may amplify risk for restricted dietary preferences (picky eating) and poor self-regulation of food intake that could contribute to suboptimal diets in survivorship. This study aims to: (a) characterize differences in picky eating and self-regulation of food intake between survivors and peer controls; and (b) examine the associations between these eating behaviors and dietary quality in ALL survivors relative to peer controls. METHODS: Participants were children (5-13 years) with (n = 32) and without (n = 32) a history of ALL and their caregivers. Children's dietary quality (Healthy Eating Index-2015) was calculated from 24-h dietary recalls. Caregivers completed the Child Eating Behavior Questionnaire-Food Fussiness subscale and the Child Self-Regulation in Eating Questionnaire. RESULTS: Independent samples t-tests revealed survivors exhibited greater picky eating than peer controls but comparable self-regulation of food intake. Bootstrapped grouped multivariate regression results showed that for ALL survivors, greater picky eating was associated with worse dietary quality (controlling for age and self-regulation of food intake). For peer controls, worse self-regulation of food intake was associated with poorer dietary quality (controlling for picky eating and age). CONCLUSIONS: Results provide preliminary support that different eating behaviors contribute to poor dietary quality in children with and without an ALL history. These findings suggest that interventions to improve ALL survivors' dietary quality may benefit targeting picky eating.

Incidence and Risk Factors for 30-Day Readmission after Inpatient Chemotherapy among Acute Lymphoblastic Leukemia Patients.

Chemotherapy for acute lymphoblastic leukemia (ALL) patients is complex and intense, resulting in a high readmission rate. We aimed to identify the incidence, causes, and risk factors of readmission following inpatient chemotherapy among ALL patients, using 2016 National Readmission Database. We applied three different definitions of 30-day readmission: (1) nonelective readmission based on readmission type, (2) unplanned readmission defined by CMS, and (3) unintentional readmission, combining (1) and (2). We used unweighted multivariable Poisson regression with robust variance estimates for risk factors analysis, including patient-, hospital-, and admission-related characteristics. Percentage for nonelective, unplanned, and unintentional readmission were 33.3%, 22.4%, and 18.5%, respectively. The top three causes for unplanned readmissions were neutropenia/agranulocytosis (27.8%), septicemia (15.3%), and pancytopenia (11.5%). Risk ratios for unintentional readmission were 1.21 (1.08-1.36) for nonelective vs. elective admission, 1.19 (1.06-1.33) for public vs. private insurance enrollees, 0.96 (0.95-0.98) for each day of hospital stay, 0.77 (0.62-0.95) for large teaching and 0.87 (0.70-1.08) for small teaching vs. nonteaching hospitals. Possible strategies to reduce readmission among ALL patients could be shortening the gap in quality of care among teaching vs. non-teaching hospitals, understanding the difference between privately vs. publicly insured patients, and avoiding aggressive discharge after chemotherapy.

How we approach Philadelphia chromosome-positive acute lymphoblastic leukemia in children and young adults.

Treatment for children with Philadelphia chromosome-positive acute lymphoblastic leukemia has changed radically over the past 20 years. This type of leukemia used to have dismal prognosis, but today cure rates have improved with combination of cytotoxic chemotherapy and a tyrosine kinase inhibitor such as imatinib or dasatinib, with hematopoietic stem cell transplant reserved for patients who are at high risk based on slow response to therapy or who relapse. Treating these patients can be challenging particularly if they are not enrolled on a clinical trial. Here, we describe our approach to these patients.

Primary pulmonary artery sarcoma in the pediatric patient: Review of literature and a case report.

Primary pulmonary artery sarcoma (PAS) is extremely rare in children. Nevertheless, distinguishing primary PAS from pulmonary embolism is critical to a child's survival. Primary PAS is commonly misdiagnosed as a pulmonary embolism due to similar presenting symptoms and radiographic findings. However, compared to adults, pulmonary embolism is rare in children, especially in patients who do not have predisposing factors or hypercoagulable state. We present a child with primary PAS which mimicked pulmonary embolism on presentation but eventually was resected and is doing well 5 years after resection. In the absence of predisposing factors or hypercoagulable state, solid tumors such as primary PAS should be considered when assessing a pediatric patient with presumed pulmonary embolism.

Irradiating Residual Disease to 30 Gy with Proton Therapy in Pediatric Mediastinal Hodgkin Lymphoma.

BACKGROUND: Local relapse is a predominant form of recurrence among pediatric patients with Hodgkin lymphoma (PHL). Although PHL radiotherapy doses have been approximately 20 Gy, adults with Hodgkin lymphoma receiving 30 to 36 Gy experience fewer in-field relapses. We investigated the dosimetric effect of such a dose escalation to the organs at risk (OARs). MATERIALS AND METHODS: Ten patients with PHL treated with proton therapy to 21 Gy involved-site radiation therapy (ISRT21Gy) were replanned to deliver 30 Gy by treating the ISRT to 30 Gy (ISRT30Gy), delivering 21 Gy to the ISRT plus a 9-Gy boost to postchemotherapy residual volume (rISRTboost), and delivering 30 Gy to the residual ISRT target only (rISRT30Gy). Radiation doses to the OARs were compared. RESULTS: The ISRT30Gy escalated the dose to the target by 42% but also to the OARs. The rISRTboost escalated the residual target dose by 42%, and the OAR dose by only 17% to 26%. The rISRT30Gy escalated the residual target dose by 42% but reduced the OAR dose by 25% to 46%. CONCLUSION: Boosting the postchemotherapy residual target dose to 30Gy can allow for dose escalation with a slight OAR dose increase. Treating the residual disease for the full 30Gy, however, would reduce the OAR dose significantly compared with ISRT21Gy. Studies should evaluate these strategies to improve outcomes and minimize the late effects.

Post Transplant Lymphoproliferative Disorder risk factors in children: Analysis of a 23-year single-institutional experience.

INTRODUCTION: PTLD is the most frequent malignancy following SOT in children and the second most common SOT complication in adults. However, factors determining outcomes in children are poorly understood due to its relative rarity. METHODS: This study was performed at the University of Florida. Univariate and multivariate analyses were used to identify prognostic factors in pediatric patients diagnosed with PTLD. RESULTS: We reviewed records of 54 pediatric (younger than 18 years old at diagnosis) patients diagnosed with PTLD from 1994 to 2017. The median follow-up was 28.8 months. The estimated 5-year survival rate was 87.6% (95% CI 74.3-94.2%). Univariate analysis showed that organ transplanted (specifically heart transplant), poor response to initial treatment, allograft rejection, and low Karnofsky score were statistically significant for negative prognostic factors in determining survival. Multivariate analysis determined progression in response to initial treatment and presence of allograft rejection as statistically significant prognostic factors affecting overall survival. We found no statistically significant impact of EBV serological status on PTLD prognosis. CONCLUSIONS: Disease progression and allograft rejection were strong negative prognostic indicators in our study cohort. Close attention to graft status and development of therapies that protect the graft from rejection while bolstering anti-EBV immunity will be essential to further improving PTLD outcomes in children.

GD2 chimeric antigen receptor modified T cells in synergy with sub-toxic level of doxorubicin targeting osteosarcomas.

Since the prognosis for children with high-risk osteosarcoma (OS) remains suboptimal despite intensive multi-modality therapies, there is a clear and urgent need for the development of targeted therapeutics against these refractory malignancies. Chimeric antigen receptor (CAR) modified T cells can meet this need by utilizing the immune system's potent cytotoxic mechanisms against tumor specific antigen targets with exquisite specificity. Since OS highly expresses the GD2 antigen, a viable immunotherapeutic target, we sought to assess if CAR modified T cells targeting GD2 could induce cytotoxicity against OS tumor cells. We demonstrated that the GD2 CAR modified T cells were highly efficacious for inducing OS tumor cell death. Interestingly, the OS cells were induced to up-regulate expression of PD-L1 upon interaction with GD2 CAR modified T cells, and the specific interaction induced CAR T cells to overexpress the exhaustion marker PD-1 along with increased CAR T cell apoptosis. To further potentiate CAR T cell killing activity against OS, we demonstrated that suboptimal chemotherapeutic treatment with doxorubicin can synergize with CAR T cells to effectively kill OS tumor cells.

A genomics-informed computational biology platform prospectively predicts treatment responses in AML and MDS patients.

Patients with myelodysplastic syndromes (MDS) or acute myeloid leukemia (AML) are generally older and have more comorbidities. Therefore, identifying personalized treatment options for each patient early and accurately is essential. To address this, we developed a computational biology modeling (CBM) and digital drug simulation platform that relies on somatic gene mutations and gene CNVs found in malignant cells of individual patients. Drug treatment simulations based on unique patient-specific disease networks were used to generate treatment predictions. To evaluate the accuracy of the genomics-informed computational platform, we conducted a pilot prospective clinical study (NCT02435550) enrolling confirmed MDS and AML patients. Blinded to the empirically prescribed treatment regimen for each patient, genomic data from 50 evaluable patients were analyzed by CBM to predict patient-specific treatment responses. CBM accurately predicted treatment responses in 55 of 61 (90%) simulations, with 33 of 61 true positives, 22 of 61 true negatives, 3 of 61 false positives, and 3 of 61 false negatives, resulting in a sensitivity of 94%, a specificity of 88%, and an accuracy of 90%. Laboratory validation further confirmed the accuracy of CBM-predicted activated protein networks in 17 of 19 (89%) samples from 11 patients. Somatic mutations in the TET2, IDH1/2, ASXL1, and EZH2 genes were discovered to be highly informative of MDS response to hypomethylating agents. In sum, analyses of patient cancer genomics using the CBM platform can be used to predict precision treatment responses in MDS and AML patients.

Functional Improvement of Chimeric Antigen Receptor Through Intrinsic Interleukin-15Rα Signaling.

INTRODUCTION: Recent studies on CD19-specific chimeric antigen receptor (CAR)-modified T cells (CARTs) have demonstrated unprecedented successes in treating refractory and relapsed B cell malignancies. The key to the latest CART therapy advances can be attributed to the improved costimulatory signals in the CAR design. METHODS: Here, we established several novel CARs by incorporating T cell signaling domains of CD28 in conjunction with intracellular signaling motif of 4-1BB, CD27, OX40, ICOS, and IL-15Rα. These novel CARs were functionally assessed based on a simple target cell killing assay. RESULTS: The results showed that the CD28/IL-15Rα co-signaling (153z) CAR demonstrated the fastest T cell expansion potential and cytotoxic activities. IL-15 is a key cytokine that mediates immune effector activities. The 153z CARTs maintained prolonged killing activities after repetitive rounds of target cell engagement. Consistent with the enhanced target killing function, the 153z CARTs produced increased amount of effector cytokines including IFN-γ, TNFα and IL-2 upon interaction with the target cells. CONCLUSION: In a follow-up clinical study, an acute lymphoblastic leukemia (ALL) patient, who experienced multiple relapses of central nervous system leukemia (CNSL) and failed all conventional therapies, was enrolled to receive the CD19-specific 153z CART treatment. The patient achieved complete remission after the 153z CART cell infusion. The translational outcome supports further investigation into the safety and enhanced therapeutic efficacy of the IL-15Rα-modified CART cells in cancer patients.

Dasatinib Plus Intensive Chemotherapy in Children, Adolescents, and Young Adults With Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia: Results of Children's Oncology Group Trial AALL0622.

Purpose Addition of imatinib to intensive chemotherapy improved survival for children and young adults with Philadelphia chromosome-positive acute lymphoblastic leukemia. Compared with imatinib, dasatinib has increased potency, CNS penetration, and activity against imatinib-resistant clones. Patients and Methods Children's Oncology Group (COG) trial AALL0622 (Bristol Myers Squibb trial CA180-204) tested safety and feasibility of adding dasatinib to intensive chemotherapy starting at induction day 15 in patients with newly diagnosed Philadelphia chromosome-positive acute lymphoblastic leukemia age 1 to 30 years. Allogeneic hematopoietic stem-cell transplantation (HSCT) was recommended for patients at high risk based on slow response and for those with a matched family donor regardless of response after at least 11 weeks of therapy. Patients at standard risk based on rapid response received chemotherapy plus dasatinib for an additional 120 weeks. Patients with overt CNS leukemia received cranial irradiation. Results Sixty eligible patients were enrolled. Five-year overall (OS) and event-free survival rates (± standard deviations [SD]) were 86% ± 5% and 60% ± 7% overall, 87% ± 5% and 61% ± 7% for standard-risk patients (n = 48; 19% underwent HSCT), and 89% ± 13% and 67% ± 19% for high-risk patients (n = 9; 89% underwent HSCT), respectively. Five-year cumulative incidence (± SD) of CNS relapse was 15% ± 6%. Outcomes (± SDs) were similar to those in COG AALL0031, which used the same chemotherapy with continuous imatinib: 5-year OS of 81% ± 6% versus 86% ± 5% ( P = .63) and 5-year disease-free survival of 68% ± 7% versus 60% ± 7% ( P = 0.31) for AALL0031 versus AALL0622, respectively. IKZF1 deletions, present in 56% of tested patients, were associated with significantly inferior OS and event-free survival overall and in standard-risk patients. Conclusion Dasatinib was well tolerated with chemotherapy and provided outcomes similar to those with imatinib in COG AALL0031, where all patients received cranial irradiation. Our results support limiting HSCT to slow responders and suggest a potential role for transplantation in rapid responders with IKZF1 deletions.

Minimal Change Disease as Initial Presentation of ALK-Positive Anaplastic Large-Cell Lymphoma in a Pediatric Patient.

The association between nephrotic syndrome (NS), hemophagocytic lymphohistiocytosis (HLH), and certain paraneoplastic syndromes has been documented in the literature. However, nephrotic changes as part of paraneoplastic syndromes are rare in lymphoid malignancies, particularly in non-Hodgkin lymphoma. We report the sudden onset of acute renal failure and NS in a 14-year-old male who initially presented with HLH and was subsequently diagnosed with ALK-positive anaplastic large-cell lymphoma (ALCL). The treatment of ALCL reversed both the HLH and NS findings. This case demonstrates the importance of considering lymphoma in pediatric patients presenting with NS and HLH.

Developmental Stage-Specific Manifestations of Absent TPO/c-MPL Signalling in Newborn Mice.

Congenital amegakaryocytic thrombocytopaenia (CAMT) is a disorder caused by c-MPL mutations that impair thrombopoietin (TPO) signalling, resulting in a near absence of megakaryocytes (MKs). While this phenotype is consistent in adults, neonates with CAMT can present with severe thrombocytopaenia despite normal MK numbers. To investigate this, we characterized MKs and platelets in newborn c-MPL ­/­ mice. Liver MKs in c-MPL ­/­ neonates were reduced in number and size compared with wild-type (WT) age-matched MKs, and exhibited ultrastructural abnormalities not found in adult c-MPL ­/­ MKs. Platelet counts were lower in c-MPL ­/­ compared with WT mice at birth and did not increase over the first 2 weeks of life. In vivo biotinylation revealed a significant reduction in the platelet half-life of c-MPL ­/­ newborn mice (P2) compared with age-matched WT pups, which was not associated with ultrastructural abnormalities. Genetic deletion of the pro-apoptotic Bak did not rescue the severely reduced platelet half-life of c-MPL ­/­ newborn mice, suggesting that it was due to factors other than platelets entering apoptosis early. Indeed, adult GFP+ (green fluorescent protein transgenic) platelets transfused into thrombocytopenic c-MPL ­/­ P2 pups also had a shortened lifespan, indicating the importance of cell-extrinsic factors. In addition, neonatal platelets from WT and c-MPL ­/­ mice exhibited reduced P-selectin surface expression following stimulation compared with adult platelets of either genotype, and platelets from c-MPL ­/­ neonates exhibited reduced glycoprotein IIb/IIIa (GPIIb/IIIa) activation in response to thrombin compared with age-matched WT platelets. Taken together, our findings indicate that c-MPL deficiency is associated with abnormal maturation of neonatal MKs and developmental stage-specific defects in platelet function.

Post-transplant lymphoproliferative disorder (PTLD): single institutional experience of 141 patients.

BACKGROUND: Post-transplant lymphoproliferative disorder is a well-recognized but rare complication of hematopoietic stem cell and solid organ transplant. Due to rarity of this disease, retrospective studies from major transplant centers has been the main source to provide treatment guidelines, which are still in evolution. The sample size of this study is among one of the largest study on PTLD till date reported throughout the world. METHODS: This study was performed at University of Florida which is one of the largest transplant center in South East United States. We performed treatment and survival analysis along with univariate and multivariate analysis to identify prognostic factors. RESULTS: We reviewed 141 patients diagnosed with PTLD over last 22 years with median follow-up of 2.4 years. The estimated median overall survival of the entire group was 15.0 years. Sub group analysis showed that 5-year overall survival rates of pediatric population were 88% (median not reached). For adults, median OS was 5.35 years while for elderly patients it was 1.32 years. The estimated median OS of patients with monomorphic PTLD was 9.0 years while in polymorphic PTLD was 19.3 years. Univariate analysis identified gender, age at transplant and PTLD diagnosis, performance status, IPI score, allograft type, recipient EBV status, multiple acute rejections prior to PTLD diagnosis, PTLD sub-type, extra-nodal site involvement, immunosuppressive drug regimen at diagnosis, initial treatment best response were statistically significant prognostic factors (p < 0.05). On multivariate analysis, age at PTLD diagnosis, recipient EBV status, bone marrow involvement, and initial best response were statistically significant prognostic factors (p < 0.05). Surprisingly, use of Rituximab alone as upfront therapy had poor hazard ratio in the cumulative group as well less aggressive PTLD subgroup comprising of early lesions and polymorphic PTLD. CONCLUSIONS: Our experience with treatment and analysis of outcomes does challenge current role of Rituximab use in treatment of PTLD. Currently as we define role of immunotherapy in cancer treatment, the role of acute rejections and immunosuppressant in PTLD becomes more relevant as noticed in our study. This study was also able to find new prognostic factors and also verified other known prognostic factors.