Predictors and short-term outcomes of hyperleukocytosis in children with acute myeloid leukemia: a report from the Children's Oncology Group

Red cell exchange for rapid leukoreduction in adults with hyperleukocytosis and leukostasis

ABSTRACT

We show that red cell exchange (RCE) treats hyperleukocytosis in acute leukemia. RCE provided similar leukoreduction to standard therapeutic leukoreduction and could be superior in patients with severe anemia or monocytic leukemias or when requiring rapid treatment.

Pediatric acute myeloid leukemia and hyperleukocytosis with WBC count greater than 50 × 109/L

BACKGROUND

Acute myeloid leukemia (AML) and hyperleukocytosis have an unfavorable prognosis, but the impact of hyperleukocytosis on the prognosis of pediatric AML remains uncertain. We investigated the clinical characteristics and prognosis of pediatric AML with hyperleukocytosis, defined as WBC ≥ 50 × 109/L.

METHODS

A total of 132 patients with newly diagnosed childhood AML with hyperleukocytosis were consecutively enrolled at our center from September 2009 to August 2021 to investigate prognostic factors and clinical outcomes.

RESULTS

Hyperleukocytosis occurred in 27.4% of AML patients. Pediatric patients with hyperleukocytosis had similar CR and OS rates to those without hyperleukocytosis, but had a lower EFS rate. In our study, rates of CR1, mortality, relapsed/refractory disease, and HSCT were comparable between AML patients with WBC counts of 50-100 × 109/L and ≥ 100 × 109/L. AML patients with a WBC count of 50-100 × 109/L had a similar 5-year OS rate to patients with a WBC count ≥ 100 × 109/L (74.6% vs. 75.4%, P = 0.921). Among all patients with hyperleukocytosis, the FAB M5 subtype was associated with significantly inferior survival, and the prognosis of CBF-AML was good.

CONCLUSIONS

Pediatric AML patients with hyperleukocytosis have the similar prognosis regardless of whether their WBC count is 50-100 × 109/L or ≥ 100 × 109/L.

A rare complication of leukostasis with AML M4 patient: Microcirculatory dysfunction of upper extremities

BACKGROUND

In children with acute myeloid leukemia, the incidence of hyperleukocytosis is 5-33%. Patients with AML and hyperleukocytosis have a higher early mortality rate than patients with nonhyperleukocytic AML because of the increased risk of severe pulmonary and neurologic complications. Leukapheresis provides rapid cytoreduction and reduces early mortality rates.

CASE PRESENTATION

In this report, we present a case with microcirculatory failure of upper extremities as a rare symptom of hyperleukocytic AML M4 at initial presentation.

CONCLUSIONS

Early diagnosis and treatment of patients with AML admitted to emergency services with these symptoms is too important to prevent from loss of extremities. Most of the complications of hyperleukocytosis can be reversible with early treatment.

Clinical characteristics and outcomes of children with newly diagnosed acute myeloid leukemia and hyperleukocytosis managed with different cytoreductive methods

BACKGROUND

Hyperleukocytosis in patients with acute myeloid leukemia (AML) has been associated with worse outcomes. For cytoreduction, leukapheresis has been used but its clinical utility is unknown, and low-dose cytarabine (LD-cytarabine) is used as an alternative method.

METHODS

Children with newly diagnosed AML treated between 1997 and 2017 in institutional protocols were studied. Hyperleukocytosis was defined as a leukocyte count of ≥100 × 109 /L at diagnosis. Clinical characteristics, early complications, survival data, and effects of cytoreductive methods were reviewed. Among 324 children with newly diagnosed AML, 49 (15.1%) presented with hyperleukocytosis. Initial management of hyperleukocytosis included leukapheresis or exchange transfusion (n = 16, considered as one group), LD-cytarabine (n = 18), hydroxyurea (n = 1), and no leukoreduction (n = 14).

RESULTS

Compared with patients who received leukapheresis, the percentage decrease in leukocyte counts following intervention was greater among those who received LD-cytarabine (48% vs. 75%; p = .02), with longer median time from diagnosis to initiation of protocol therapy (28.1 vs. 95.2 hours; p < .001). The incidence of infection was higher in patients (38%) who had leukapheresis than those who receive LD-cytarabine (0%) or leukoreduction with protocol therapy (14%) (p = .008). No differences were noted in the outcomes among the intervention groups. Although patients with hyperleukocytosis had higher incidences of pulmonary and metabolic complications than did those without, no early deaths occurred, and the complete remission, event-free survival, overall survival rates, and outcomes of both groups were similar.

CONCLUSION

LD-cytarabine treatment appears to be a safe and effective means of cytoreduction for children with AML and hyperleukocytosis.

Hyperleukocytosis in Childhood Acute Leukemia: Early Complications and Survival Outcomes

Hyperleukocytosis and extreme hyperleukocytosis, defined as initial white blood cell counts greater than 100 × 10⁹/L and 200 × 10⁹/L, respectively, have been associated with unfavorable outcomes. This study aimed to determine the early complications and survival outcomes of childhood leukemia patients with hyperleukocytosis. The medical records of 690 children newly diagnosed with acute leukemia between January 1998 and December 2017 were retrospectively reviewed. The Kaplan-Meier method and log-rank test were used to assess and compare the survival outcomes. Multivariate Cox proportional hazards regression was used to determine associated risk factors for overall survival. We found that 16.6% of 483 childhood acute lymphoblastic leukemia (ALL) patients and 20.3% of 207 childhood acute myeloid leukemia (AML) patients had hyperleukocytosis at diagnosis. ALL patients with hyperleukocytosis had more early complications than those without hyperleukocytosis (p < 0.05). Among the ALL group, the 5-year overall survival rate for those with hyperleukocytosis was significantly lower than for those without hyperleukocytosis (37.2% vs. 67.8%, p < 0.0001), while the difference was not statistically significant in the AML group (19.0% vs. 30.2%, respectively, p = 0.26). Hyperleukocytosis (hazard ratio [HR]: 2.04), extreme hyperleukocytosis (HR: 2.71), age less than 1 year (HR: 3.05), age greater than 10 years (HR: 1.64), and male sex (HR: 1.37) were independently associated with poorer overall survival in childhood ALL patients. Extreme hyperleukocytosis (HR: 2.63) and age less than 1 year (HR: 1.82) were independently associated with poorer overall survival in AML patients. Hyperleukocytosis was associated with adverse survival outcomes in childhood leukemia.

Take a spin: Apheresis in the care of adult leukaemia patients

Apheresis is an automated process to separate the whole blood of a patient or a donor, collect or remove specific blood components, and return the remaining back to the individual. Apheresis is an integral part of blood and marrow transplantation and has been increasingly utilized in novel cellular therapies for a variety of blood disorders. This review uses clinical cases to highlight the multiple roles of apheresis in the care of adult leukaemia patients, including therapeutic leukapheresis in hyperleukocytosis, mobilized peripheral blood hematopoietic progenitor cell collection in donors, mononucleated cell collection in preparation of donor lymphocyte infusion or chimeric antigen receptor T cells manufacture, and extracorporeal photopheresis in the treatment of graft versus host diseases.

Management of Hyperleukocytosis in Childhood Acute Leukemia Without Leukapheresis and Rasburicase Prophylaxis

Indications of leukapheresis (LPh) and the prophylactic use of rasburicase in tumor lysis syndrome (TLS) of patients with acute leukemia with hyperleukocytosis are not clear. In this retrospective single-center pediatric study, the outcomes of patients with hyperleukocytosis were reviewed. There were 48 patients with acute lymphoblastic leukemia (ALL) and 13 patients with acute myeloblastic leukemia (AML). The treatment strategies included hyperhydration, allopurinol administration, strict monitoring, and early initiation of induction chemotherapy (CT). No patient underwent LPh because it was not available. Rasburicase was used only in 3 ALL patients with hyperuricemia when the drug was available. Laboratory and clinical TLS developed in 54.16% and 14.58% of patients with ALL, respectively. Laboratory and clinical TLS developed in 76.92% and 15.38% of patients with AML, respectively. No patient developed grade III to V TLS requiring dialysis. Thirteen patients (21.3%) had pulmonary leukostasis on admission, but recovered with CT and nasal oxygen. During the first 14 days of presentation, cerebral leukostasis/coagulopathy-related early death (ED) was 4.2% and 7.7% in patients with ALL and AML, respectively, and all of these patients had a white blood cell count ≥400,000/µL. There was also 1 infection-related death. Patients with hyperleukocytosis can be treated without LPh and liberal use of rasburicase. Renal failure is no longer a cause of ED. Intracranial hemorrhage is the main cause of ED, especially in patients already presenting with this complication. LPh may be performed in patients with leukostasis, if it is not possible to start induction CT early. When resources are limited, rasburicase should be administered in patients presenting with or developing hyperuricemia and/or renal dysfunction.

Leukoreductive response to the combination of sorafenib and chemotherapy in hyperleukocytosis of FLT3-ITD mutated pediatric AML

Twelve to 22% of pediatric acute myeloid leukemia (AML) patients present with hyperleukocytosis, which is one of the main risk factors of early death due to its clinical complications: leukostasis, causing pulmonary or central nervous system injuries, tumor lysis syndrome, and disseminated intravascular coagulation. Sorafenib is a multi-kinase inhibitor that blocks the Fms-Related Tyrosine Kinase 3 receptor (FLT3) in AML patients with a FLT3-internal tandem duplication (FLT3-ITD), leading to a reduction of proliferation. Here we report four de novo diagnosed or relapsed pediatric FLT3-ITD-positive AML patients with hyperleukocytosis, which were treated with sorafenib in combination with cytoreductive chemotherapy prior to the start of the induction phase. We observed a fast reduction of white blood cells in peripheral blood and bone marrow. This resulted in a rapid clinical stabilization of the patients. Adverse side effects-such as dermatologic toxicity, elevation of transaminases and hypertension-occurred but were mild and inductive chemotherapy could be started in parallel or subsequently. This implies sorafenib as a safe and effective treatment option in combination with chemotherapy during cytoreductive prephase for children with this life-threatening condition.

Intracranial Hemorrhage Associated With T-Cell Acute Lymphoblastic Leukemia With Hyperleukocytosis: A Case Report

Acute leukemia in children may present with hyperleukocytosis. Symptomatic hyperleukocytosis is a medical emergency that necessitates rapid stabilization of the patient and prompt lowering of the leukocyte count. We report on a patient with intracranial hemorrhage associated with T-cell acute lymphoblastic leukemia with hyperleukocytosis, which is a rare occurrence. A 16-year-old boy with hyperleukocytosis (total white cell count; 398×103/µL) underwent repeated leukapheresis and received supportive treatment until a definite diagnosis of T-cell acute lymphoblastic leukemia was made and chemotherapy was started at 10% of the usual dose. On day 2 of treatment, he had headache, vomiting, and was agitated. Brain magnetic resonance imaging showed bilateral extensive hemispheric and cerebellar punctate areas of hemorrhage and perilesional edema. Chemotherapy intensified to a maximum dose on day 3. If supportive care for tumor lysis syndrome can be promptly provided, initial chemotherapy regimen can immediately be begun at an optimal dose.

Leukapheresis and Hyperleukocytosis, Past and Future

Hyperleukocytosis is a hematologic crisis caused by excessive proliferation of leukemic cells and has a relatively high early mortality due to a series of severe complications. Therefore, prompt and effective intervention is required. Leukapheresis performed using apheresis equipment to separate leukocytes from peripheral blood, at the same time returns autologous plasma, platelets and erythrocytes to the patient, is applied clinically for the treatment of hyperleukocytosis. Leukapheresis not only removes excessive leukocytes rapidly and corrects metabolic abnormalities but also alleviates the symptoms of leukostasis. In addition, the procedure of leukapheresis is generally well tolerated. Leukapheresis has become one of the most imperative adjuvant therapies to treat hyperleukocytosis, especially in the patient who was not inappropriate to cytoreduce with Ara-C or hydroxyurea. In this review, we present the background of leukapheresis development and highlight its clinical application in hyperleukocytic leukemia patients.

Small molecules in targeted cancer therapy: advances, challenges, and future perspectives

Due to the advantages in efficacy and safety compared with traditional chemotherapy drugs, targeted therapeutic drugs have become mainstream cancer treatments. Since the first tyrosine kinase inhibitor imatinib was approved to enter the market by the US Food and Drug Administration (FDA) in 2001, an increasing number of small-molecule targeted drugs have been developed for the treatment of malignancies. By December 2020, 89 small-molecule targeted antitumor drugs have been approved by the US FDA and the National Medical Products Administration (NMPA) of China. Despite great progress, small-molecule targeted anti-cancer drugs still face many challenges, such as a low response rate and drug resistance. To better promote the development of targeted anti-cancer drugs, we conducted a comprehensive review of small-molecule targeted anti-cancer drugs according to the target classification. We present all the approved drugs as well as important drug candidates in clinical trials for each target, discuss the current challenges, and provide insights and perspectives for the research and development of anti-cancer drugs.

Hyperleukocytosis predicts inferior clinical outcome in pediatric acute myeloid leukemia

OBJECTIVES

Hyperleukocytosis (HL) is a laboratory abnormality commonly presented in patients with acute myeloid leukemia (AML). However, large cohort studies on the clinical significance of HL in pediatric AML are paucity. Moreover, the effect of stem cell transplantation in HL patients remains unknown.

METHODS

The clinical profiles of 885 pediatric patients with AML were downloaded from the TARGET dataset. HL was defined as an initial peripheral WBC count of ≥ 100 ×10⁹/L. We analyzed the prevalence, clinical profile and prognosis of HL in these patients.

RESULTS

The frequency of HL among all the pediatric AML was 22.6%. FMS-like tyrosine kinase 3/internal tandem duplication (FLT3/ITD) mutation and gene fusion of NUP98/NSD1 occurred with higher incidence in HL patients. Overall, HL was associated with a low induction complete remission rate, and high risk of induction death. Moreover, HL predicted a significantly inferior 5-year event-free survival (EFS) (P < 0.001) and a trend of inferior 5-year overall survival (OS) (P = 0.059). However, compared with chemotherapy, stem cell transplantation had no significant effect on the survival of HL patients in terms of 5-year leukemia-free survival (P = 0.449) or OS (P = 0.447). Multivariate analysis revealed that HL was an independent prognosis factor for EFS (Hazard ratio:1.352, P = 0.013) but not for OS (Hazard ratio:1.225, P = 0.170) in pediatric AML.

CONCLUSION

HL might predict inferior clinical outcome in pediatric AML. SCT is an effective therapy for AML, but it may have no better effect on the survival of patients with HL, compared to chemotherapy.

[Efficacy and prognostic factors in children with non-core binding factor acute myeloid leukemia]

OBJECTIVE

To compare the efficacy of the CAMS-2005 and CAMS-2009 regimens in treating children with non-core binding factor acute myeloid leukemia (non-CBF AML) and to study the prognosis factors.

METHODS

A total of 161 children who were initially diagnosed with non-CBF AML from April 2005 to December 2015 were enrolled as study subjects, and were divided into a CAMS-2005 regimen group (n=52) and a CAMS-2009 regimen group (n=109) according to the chemotherapy regimen provided. The efficacy was retrospectively compared between the two groups.

RESULTS

The complete remission (CR) rate at the first course of treatment was higher in the CAMS-2009 regimen group than that in the CMAS-2005 regimen group (63.3% vs 46.2%; P<0.05). There were no significant differences between the two groups in treatment-related mortality rate (11.9% vs 17.3%), recurrence rate (27.5% vs 28.8%), and three-year overall survival (OS) rate (44%±5% vs 28%±6%) (P>0.05). Children who achieved CR at the first course of treatment had significantly higher OS and event-free survival rates than those who did not achieved CR (P<0.01).

CONCLUSIONS

The CAMS-2009 regimen is superior to the CAMS-2005 regimen in improving the CR rate in children with non-CBF AML after induction treatment. Whether CR is achieved at the first course of treatment can affect the OS rate of children with non-CBF AML.

[Efficacy and prognostic factors in children with non-core binding factor acute myeloid leukemia]

OBJECTIVE

To compare the efficacy of the CAMS-2005 and CAMS-2009 regimens in treating children with non-core binding factor acute myeloid leukemia (non-CBF AML) and to study the prognosis factors.

METHODS

A total of 161 children who were initially diagnosed with non-CBF AML from April 2005 to December 2015 were enrolled as study subjects, and were divided into a CAMS-2005 regimen group (n=52) and a CAMS-2009 regimen group (n=109) according to the chemotherapy regimen provided. The efficacy was retrospectively compared between the two groups.

RESULTS

The complete remission (CR) rate at the first course of treatment was higher in the CAMS-2009 regimen group than that in the CMAS-2005 regimen group (63.3% vs 46.2%; P<0.05). There were no significant differences between the two groups in treatment-related mortality rate (11.9% vs 17.3%), recurrence rate (27.5% vs 28.8%), and three-year overall survival (OS) rate (44%±5% vs 28%±6%) (P>0.05). Children who achieved CR at the first course of treatment had significantly higher OS and event-free survival rates than those who did not achieved CR (P<0.01).

CONCLUSIONS

The CAMS-2009 regimen is superior to the CAMS-2005 regimen in improving the CR rate in children with non-CBF AML after induction treatment. Whether CR is achieved at the first course of treatment can affect the OS rate of children with non-CBF AML.

Prognostic stratification of molecularly and clinically distinct subgroup in children with acute monocytic leukemia

Background

The prognosis of children with acute monocytic leukemia (AML‐M5) remains unsatisfactory and the risk profile is still controversial. We aim to investigate the prognostic value of clinical and cytogenetic features and propose a new risk stratification in AML‐M5 children.

Methods

We included 132 children with AML‐M5. Overall survival (OS) and progression‐free survival (PFS) were documented. Cox regression was performed to evaluate the potential risk factors of prognosis.

Results

The 5‐year‐OS was 46.0% (95% confidence intervals, 41.6%‐50.4%) in all patients. There was significantly lower OS in the age ≤ 3 years old (P = .009) and hyperleukocytosis (P < .001). The FMS‐like tyrosine kinase 3 (FLT3)‐internal tandem duplication (ITD) and MLL‐rearrangement carriers were associated with fewer survivors in all patients (37.1% and 36.7%) and chemotherapy‐only group (19.0% and 35.0%). Notably, the number of survivor with MLL‐rearrangement did not increase in hematopoietic stem cell transplant (HSCT) group. According to the Cox regression analysis, HSCT was a significantly favorable factor (P = .001), while hyperleukocytosis, age ≤ 3 years old, and BM blast ≥ 70% adversely affected the OS in all patients (all P < .05). Additionally, FLT3‐ITD was a risk factor for OS in the chemotherapy‐only group (P = .023), while hyperleukocytosis and age ≤ 3 years independently contributed to poor PFS (both P < .05). In comparison to the standard‐risk group, significant poorer outcome was found in the high‐risk group (both P < .005).

Conclusions

We propose that AML‐M5 children with any of MLL‐rearrangement, FLT3‐ITD, hyperleukocytosis, BM blast ≥ 70%, or age ≤ 3 years old are classified into the high‐risk group, and HSCT is beneficial especially in patients with FLT3‐ITD mutation, hyperleukocytosis, and age ≤ 3 years old. Importantly, the choice of HSCT should be made more carefully in children with MLL‐rearrangement for its suboptimal performance.

Impact of fluid overload and infection on respiratory adverse event development during induction therapy for childhood acute myeloid leukemia

BACKGROUND

Treatment-related morbidity and mortality occur frequently in childhood acute myeloid leukemia (AML) induction. Yet the contributions of respiratory adverse events (AEs) within this population are poorly understood. Furthermore, the roles of fluid overload (FO) and infection in AML pulmonary complications have been inadequately examined.

OBJECTIVES

To describe the incidence, categories, and grades of respiratory AEs and to assess the associations of FO and infection on respiratory AE development in childhood AML induction.

METHODS

We retrospectively examined the induction courses of a cohort of de novo pediatric AML patients for any NCI CTCAE grade 2 to 5 respiratory AE, FO, and systemic/pulmonary infection occurrence. Demographic, disease, and treatment-related data were abstracted. Descriptive, univariate, survival, and multivariable analyses were conducted.

RESULTS

Among 105 eligible subjects from 2009 to 2016, 49.5% (n = 52) experienced 63 discrete respiratory AEs. FO occurred in 28.6% of subjects (n = 30), with half occurring within 24 hours of hospitalization. Positive FO status < 10 days (aHR 5.5, 95% CI 2.3-12.8), ≥ 10 days (aHR 13, 95% CI 4.1-41.8), and positive infection status ≥ 10 days into treatment (aHR 14.9, 5.4-41.6) were each independently associated with AE development.

CONCLUSIONS

We describe a higher incidence of respiratory AEs during childhood AML induction than previously illustrated. FO occurs frequently and early in this course. Late infections and FO at any time frame were strongly associated with AE development. Interventions focused on the prevention and management of FO and infectious respiratory complications could be instrumental in reducing preventable treatment-related morbidity and mortality.

Sepsis-induced Hyperleukocytosis in a Preterm

Hyperleukocytosis is defined as a white blood cell (WBC) count of ≥ 100,000/µL. Leukostasis refers to symptomatic hyperleukocytosis and is considered a medical emergency. In pediatric practice, hyperleukocytosis is most commonly described in leukemia and other myeloproliferative disorder, but other etiologies, such as infection, are less commonly mentioned. In this case report, a one-day-old, preterm, male baby (26 weeks of gestation) was referred for preterm care. A sepsis-induced leukemoid reaction hyperleukocytosis diagnosis was presumed, and he was successfully treated with an empirical antibiotic with a gradual improvement in WBC counts.

Therapeutic leukocytapheresis in infants and children with leukemia and hyperleukocytosis: A single institution experience

BACKGROUND

Hyperleukocytosis, defined as white blood cell (WBC) count above 100 × 10⁹ /L, has high early morbidity and mortality from leukostasis-related complications, namely intracranial hemorrhage and pulmonary distress. Initiating chemotherapy without prior leukocytoreduction may lead to tumor lysis syndrome (TLS). Therapeutic leukocytapheresis (TL) is used as one leukocytoreductive intervention; however, its safety and efficacy in pediatric leukemia has not been established. The purpose of this study is to evaluate safety of TL in pediatric patients and assess the efficacy of TL in reducing WBC count in pediatric leukemia.

METHODS

Retrospective chart review was conducted on 14 patients with acute lymphoblastic leukemia (ALL) and 5 with acute myeloid leukemia (AML) who underwent TL during the period 2000-2014 at a single institution.

RESULTS

Mean WBC count of 19 patients who received TL was 483.2 × 10⁹ /L (547.1 in ALL, 304.3 in AML); a portion of patients presented with central nervous system symptoms (15%), respiratory symptoms (10%), or both (10%). TL reduced WBC count (mean 50.7% reduction after a single TL procedure; additional 17.1% reduction after a second TL procedure in 6 patients). Short-term survival immediately following TL was 100% without any major procedural complication. Mean survival time in patients with AML was 1.5 years and with ALL was 6.5 years.

CONCLUSIONS

TL significantly reduces WBC number in pediatric leukemia patients as young as 22 days old. In our retrospective study, TL was not associated with any significant complications and suggests that TL is a safe initial procedure in pediatric leukemia.

Leukapheresis in 15 patients weighing 20kg or less: A single centre experience

The application of apheresis equipment to perform leukapheresis (LK) in low weight paediatric patients is logistically complex and lacking of largest clinical performing experiences, meanwhile, the benefit from LK is controversial. In this study, 15 children with acute lymphoblastic leukemia(ALL)and acute myeloid leukemia (AML) and hyperleukocytosis were treated with the COBE Spectra apheresis system in the general paediatric ward by the staff from the department of Blood Transfusion. 26 LK procedures were performed. 12 patients (80%) were performed with peripheral veins, others (20%) with femoral veins. Median age, body weight of the patients was 4 years (range from1year 10 month to 7 years) and 15kg (range from10 to 20kg). The median white blood cell (WBC) count of pre-first-LK was 289×10⁹/L (range from 108×10⁹/L to 579×10⁹/L). The median decrease in WBC count after each LK was 34% (range from 14% to 54%), and overall decrease in WBC after completion of LK procedures was 45% (range from 15% to 70%). All of the patients had no further signs of leukostasis and achieved marked reductions in WBC counts. Only minor clinical adverse events were attributable to LK. With adequate monitoring and experienced team, LK is a safe and may be a beneficial leukoreduction method in small patients weighing 20kg or less with ALL and AML.

Generating Peripheral Blood Derived Lymphocytes Reacting Against Autologous Primary AML Blasts

Expanding on our prior studies with cord blood T cells, we hypothesized that primary acute myeloid leukemia (AML)-reactive autologous T cells could be generated ex vivo under immunomodulatory conditions. We purified AML and T cells from 8 newly diagnosed high-risk patients. After 2 weeks expansion, T cells were stimulated with interferon-γ-treated autologous AML weekly × 3, interleukin-15, and agonistic anti-CD28 antibody. Cytotoxic T cells and ELISpot assays tested functionality; reverse transcriptase quantitative polymerase chain reaction tested AML and T-cell gene expression profiles. On the basis of combined positive ELIspot and cytotoxic T cells assays, T cells reactive against AML were generated in 5 of 8 patients. Treg proportion declined after cocultures in reactive T-cell samples. AML-reactive T cells displayed an activated gene expression profile. "Resistant" AML blasts displayed genes associated with immunosuppressive myeloid-derived suppressor cells. We discuss our approach to creating primary AML-reactive autologous T cell and limitations that require further work. Our study provides a platform for future research targeting on generating autologous leukemia-reactive T cells.

The Role of Leukapheresis in the Current Management of Hyperleukocytosis in Newly Diagnosed Childhood Acute Lymphoblastic Leukemia

BACKGROUND

Hyperleukocytosis in children with acute lymphoblastic leukemia (ALL) has been associated with early morbidity and mortality. The use of leukapheresis in these children treated with contemporary therapy remains controversial.

PROCEDURE

We analyzed clinical data from patients enrolled onto frontline protocols for ALL (Total Therapy XV and XVI) between 2003 and 2014. We documented adverse events within the first 14 days in patients with a white blood cell (WBC) count ≥200 × 10(9) /l and reviewed their management.

RESULTS

Fifty-three (7.8%) of 678 consecutive pediatric patients with newly diagnosed ALL presented with hyperleukocytosis (median WBC count 393 × 10(9) /l; range 200-1,014). Two deaths in patients without initial hyperleukocytosis occurred within the first 2 weeks from diagnosis secondary to bacterial sepsis. A total of 21 (40%) patients with ALL and hyperleukocytosis developed grade 3 or 4 adverse events regardless of the use of leukapheresis (P > 0.99 and P = 0.19). Sixteen of 53 (30%) patients with ALL received low-dose chemotherapy for leukocytoreduction initially. One-third of patients received urate oxidase, and none of the patients with hyperleukocytosis required hemodialysis.

CONCLUSIONS

The early morbidity and mortality commonly associated with hyperleukocytosis in children with newly diagnosed ALL can be avoided with contemporary supportive care and conservative management possibly obviating the need for costly and potentially dangerous leukapheresis.

Acute Myeloid Leukemia: analysis of epidemiological profile and survival rate

OBJECTIVE

To describe the epidemiological profile and the survival rate of patients with acute myeloid leukemia (AML) in a state reference pediatric hospital.

METHOD

Clinical-epidemiological, observational, retrospective, descriptive study. The study included new cases of patients with AML, diagnosed between 2004 and 2012, younger than 15 years.

RESULTS

Of the 51 patients studied, 84% were white; 45% were females and 55%, males. Regarding age, 8% were younger than 1 year, 47% were aged between 1 and 10 years, and 45% were older than 10 years. The main signs/symptoms were fever (41.1%), asthenia/lack of appetite (35.2%), and hemorrhagic manifestations (27.4%). The most affected extra-medullary site was the central nervous system (14%). In 47% of patients, the white blood cell (WBC) count was below 10,000/mm(3) at diagnosis. The minimal residual disease (MRD) was less than 0.1%, on the 15th day of treatment in 16% of the sample. Medullary relapse occurred in 14% of cases. When comparing the bone marrow MRD with the vital status, it was observed that 71.42% of the patients with type M3 AML were alive, as were 54.05% of those with non-M3 AML. The death rate was 43% and the main proximate cause was septic shock (63.6%).

CONCLUSIONS

In this study, the majority of patients were male, white, and older than 1 year. Most patients with WBC count <10,000/mm(3) at diagnosis lived. Overall survival was higher in patients with MRD <0.1%. The prognosis was better in patients with AML-M3.

Genomic Profiling of Pediatric Acute Myeloid Leukemia Reveals a Changing Mutational Landscape from Disease Diagnosis to Relapse

The genomic and clinical information used to develop and implement therapeutic approaches for acute myelogenous leukemia (AML) originated primarily from adult patients and has been generalized to patients with pediatric AML. However, age-specific molecular alterations are becoming more evident and may signify the need to age-stratify treatment regimens. The NCI/COG TARGET-AML initiative used whole exome capture sequencing (WXS) to interrogate the genomic landscape of matched trios representing specimens collected upon diagnosis, remission, and relapse from 20 cases of de novo childhood AML. One hundred forty-five somatic variants at diagnosis (median 6 mutations/patient) and 149 variants at relapse (median 6.5 mutations) were identified and verified by orthogonal methodologies. Recurrent somatic variants [in (greater than or equal to) 2 patients] were identified for 10 genes (FLT3, NRAS, PTPN11, WT1, TET2, DHX15, DHX30, KIT, ETV6, KRAS), with variable persistence at relapse. The variant allele fraction (VAF), used to measure the prevalence of somatic mutations, varied widely at diagnosis. Mutations that persisted from diagnosis to relapse had a significantly higher diagnostic VAF compared with those that resolved at relapse (median VAF 0.43 vs. 0.24, P < 0.001). Further analysis revealed that 90% of the diagnostic variants with VAF >0.4 persisted to relapse compared with 28% with VAF <0.2 (P < 0.001). This study demonstrates significant variability in the mutational profile and clonal evolution of pediatric AML from diagnosis to relapse. Furthermore, mutations with high VAF at diagnosis, representing variants shared across a leukemic clonal structure, may constrain the genomic landscape at relapse and help to define key pathways for therapeutic targeting. Cancer Res; 76(8); 2197-205. ©2016 AACR.

Exchange Transfusion and Leukapheresis in Pediatric Patients with AML With High Risk of Early Death by Bleeding and Leukostasis

BACKGROUND

The risk of early death (ED) by bleeding/leukostasis is high in patients with AML with hyperleukocytosis (>100,000/μl). Within the pediatric AML-BFM (Berlin-Frankfurt-Münster) 98/04 studies, emergency strategies for these children included exchange transfusion (ET) or leukapheresis (LPh). Risk factors for ED and interventions performed were analyzed.

PATIENTS

Two hundred thirty-eight of 1,251 (19%) patients with AML presented with hyperleukocytosis; 23 of 1,251 (1.8%) patients died of bleeding/leukostasis.

RESULTS

ED due to bleeding/leukostasis was highest at white blood cell (WBC) count >200,000/μl (14.3%). ED rates were even higher (20%) in patients with FAB (French-American-British) M4/M5 and hyperleukocytosis >200,000/μl. Patients with WBC >200,000/μl did slightly better with ET/LPh compared to those without ET/LPh (ED rate 7.5% vs. 21.2%, P = 0.055). Multivariate WBC >200,000/μl was of strongest prognostic significance for ED (P(χ(2) ) <0.0001).

CONCLUSION

Our data confirm the high risk of bleeding/leukostasis in patients with hyperleukocytosis. ET/LPh shows a trend toward reduced ED rate due to bleeding/leukostasis and is recommended at WBC >200,000/μl, and in FAB M4/M5 even at lower WBC.

Early Complications of Hyperleukocytosis and Leukapheresis in Childhood Acute Leukemias

Hyperleukocytosis in children with acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) is associated with early morbidity and mortality. The benefit from leukapheresis is controversial, and its complications are not well defined. We analyzed the frequency of early complications in children with ALL and AML presenting with white blood cell (WBC) count >100 × 10(9)/L, and the type and frequency of complications related to leukapheresis. During a 12-year period, 84 of 634 (13%) ALL and 18 of 143 (12.5%) AML patients presented with hyperleukocytosis. Leukapheresis was performed in 18 ALL and 12 AML patients. The median initial WBC was 474 × 10(9)/L in the leukapheresis group compared with 175 × 10(9)/L in the nonleukapheresis group. Neurological leukostasis occurred in 6 ALL (7.1%) and 4 AML (22.2%) patients. Pulmonary leukostasis occurred in 16 ALL (19%) and 4 AML patients (22.2%). Neurological symptoms improved in few patients after leukapheresis, except in patients with very high WBC (>650 × 10(9)/L in ALL and >400 × 10(9)/L in AML). Leukapheresis improved respiratory symptoms in some patients but caused worsening symptoms in others. Early death was associated with neurological complications, AML diagnosis, and coagulopathy. Leukapheresis did not delay initiation of chemotherapy, nor did it impact early response to chemotherapy or long-term survival. Complications included femoral vein thrombosis, electrolyte imbalances, and hemodynamic instability, which were all reversible. The role of leukapheresis as a cytoreductive procedure in childhood hyperleukocytic leukemia remains to be well defined.

Supportive care in pediatric oncology: oncologic emergencies and management of fever and neutropenia

Advancements in the care of children with cancer have, in part, been achieved through improvements in supportive care. Situations that require prompt care can occur at the time of presentation as well as during treatment. This article discusses the approach to children with fever and neutropenia, a complication encountered daily by care providers, as well as oncologic emergencies that can be seen at the time of a child's initial diagnosis: hyperleukocytosis, tumor lysis syndrome, superior vena cava syndrome, and spinal cord compression.

Leukocytapheresis for the treatment of hyperleukocytosis secondary to acute leukemia

Patients presenting with new or recurrent acute leukemia, particularly of the myeloid lineage, with WBC counts exceeding 100 × 109/L are often considered for leukocytapheresis, especially if they are experiencing symptoms of leukostasis. These symptoms are thought to occur because of blast aggregates and WBC thrombi in the circulation, which reduce blood flow. Leukostasis may cause various complications, including hyperviscosity syndrome, vascular occlusion resulting in intracranial hemorrhages and respiratory failure, and perivascular leukemic infiltrates. Leukostasis occurs more commonly with a high WBC count and with leukemias of monocytoid lineage such as acute myelomonocytic leukemia, which is a reflection of the nature of the leukemic blasts. Leukocytapheresis is used in an effort to quickly decrease a patient's circulating blast count, which can both prevent the development of leukostasis and provide symptomatic relief of leukostasis. However, the impact of leukocytapheresis on early- and long-term mortality is controversial, with several studies producing conflicting results. In this chapter, the pathophysiology of leukostasis, performance of leukocytapheresis, and efficacy of this treatment are reviewed.

Leukapheresis and low-dose chemotherapy do not reduce early mortality in acute myeloid leukemia hyperleukocytosis: a systematic review and meta-analysis

The role of leukapheresis and low-dose chemotherapy is unclear in decreasing early mortality in acute myeloid leukemia (AML) patients with hyperleukocytosis. This systematic review was conducted to describe early mortality (deaths during first induction) in patients with AML with an initial white blood count≥100×10(9)L(-1) stratified by the approach to leukapheresis and hydroxyurea/low-dose chemotherapy. Twenty-one studies were included. Weighted mean early deaths rate (20 studies, 1354 patients) was 20.1% (95% confidence interval 15.0-25.1). Neither leukapheresis strategy (p=0.67) nor hydroxyurea/low-dose chemotherapy (p=0.23) influenced the early death rate. Early mortality related to hyperleukocytosis in AML is not influenced by universal or selected use of leukapheresis or hydroxyurea/low-dose chemotherapy.

Early deaths in pediatric acute leukemia: a population-based study

The purpose was to describe the incidence and risk factors associated with early deaths (≤ 42 days from diagnosis) among children with acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) in Ontario, Canada. The data source for this population-based, retrospective cohort study was the Pediatric Oncology Group of Ontario Networked Information System (POGONIS). Patients with acute leukemia aged ≤ 18 years diagnosed between 1990 and 2010 were included. The study population consisted of 1954 children with ALL and 403 with AML. The early death rate was 40/2357 (1.7%), with 1.1% of patients with ALL and 4.7% of patients with AML dying early. Among all 442 deaths recorded, 9.0% occurred early. Twelve/40 (30.0%) early deaths were attributed to infection. Factors associated with early deaths were AML (p < 0.0001) and age ≥ 10 years at diagnosis (p = 0.038). Future interventions to improve survival may consider focusing on the early treatment period and may target AML and older patients.