Early Complications of Hyperleukocytosis and Leukapheresis in Childhood Acute Leukemias

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.

Priapism at Diagnosis of Pediatric Chronic Myeloid Leukemia: Data Derived from a Large Cohort of Children and Teenagers and a Narrative Review on Priapism Management

Pediatric chronic myeloid leukemia (CML) is a very rare malignancy (age-related incidence 0.1/100,000) typically presenting with leucocyte counts >100,000/µL. However, clinical signs of leukostasis are observed at diagnosis in only approximately 10% of all cases and among these, priapism is infrequent. Here, we analyze data from pediatric CML registries on the occurrence of priapism heralding diagnosis of CML in 16/491 (3.2%) boys (median age 13.5 years, range 4-18) with pediatric CML. In the cohort investigated, duration of priapism resulting in a diagnosis of CML was not reported in 5 patients, and in the remaining 11 patients, occurred as stuttering priapism over 3 months (n = 1), over 6 weeks (n = 1), over 1-2 weeks (n = 2), over several days (n = 2), or 24 h (n = 1), while the remaining 4 boys reported continuous erection lasting over 11-12 h. All patients exhibited splenomegaly and massive leukocytosis (median WBC 470,000/µL, range 236,700-899,000). Interventions to treat priapism were unknown in 5 patients, and in the remaining cohort, comprised intravenous fluids ± heparin (n = 2), penile puncture (n = 5) ± injection of sympathomimetics (n = 4) ± intracavernous shunt operation (n = 1) paralleled by leukocyte-reductive measures. Management without penile puncture by leukapheresis or exchange transfusion was performed in 3 boys. In total, 7 out 15 (47%) long-term survivors (median age 20 years, range 19-25) responded to a questionnaire. All had maintained full erectile function; however, 5/7 had presented with stuttering priapism while in the remaining 2 patients priapism had lasted <12 h until intervention. At its extreme, low-flow priapism lasting for longer than 24 h may result in partial or total impotence by erectile dysfunction. This physical disability can exert a large psychological impact on patients' lives. In a narrative review fashion, we analyzed the literature on priapism in boys with CML which is by categorization stuttering or persisting as mostly painful, ischemic (low-flow) priapism. Details on the pathophysiology are discussed on the background of the different blood rheology of hyperleukocytosis in acute and chronic leukemias. In addition to the data collected, instructive case vignettes demonstrate the diagnostic and treatment approaches and the outcome of boys presenting with priapism. An algorithm for management of priapism in a stepwise fashion is presented. All approaches must be performed in parallel with cytoreductive treatment of leukostasis in CML which comprises leukapheresis and exchange transfusions ± cytotoxic chemotherapy.

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.

Epigenomic machinery regulating pediatric AML: clonal expansion mechanisms, therapies, and future perspectives

Acute myeloid leukemia (AML) is a heterogeneous disease with a genetic, epigenetic, and transcriptional etiology mainly presenting somatic and germline abnormalities. AML incidence rises with age but can also occur during childhood. Pediatric AML (pAML) accounts for 15-20% of all pediatric leukemias and differs considerably from adult AML. Next-generation sequencing technologies have enabled the research community to "paint" the genomic and epigenomic landscape in order to identify pathology-associated mutations and other prognostic biomarkers in pAML. Although current treatments have improved the prognosis for pAML, chemoresistance, recurrence, and refractory disease remain major challenges. In particular, pAML relapse is commonly caused by leukemia stem cells that resist therapy. Marked patient-to-patient heterogeneity is likely the primary reason why the same treatment is successful for some patients but, at best, only partially effective for others. Accumulating evidence indicates that patient-specific clonal composition impinges significantly on cellular processes, such as gene regulation and metabolism. Although our understanding of metabolism in pAML is still in its infancy, greater insights into these processes and their (epigenetic) modulation may pave the way toward novel treatment options. In this review, we summarize current knowledge on the function of genetic and epigenetic (mis)regulation in pAML, including metabolic features observed in the disease. Specifically, we describe how (epi)genetic machinery can affect chromatin status during hematopoiesis, leading to an altered metabolic profile, and focus on the potential value of targeting epigenetic abnormalities in precision and combination therapy for pAML. We also discuss the possibility of using alternative epidrug-based therapeutic approaches that are already in clinical practice, either alone as adjuvant treatments and/or in combination with other drugs.

Supportive care in pediatric acute myeloid leukemia:Expert-based recommendations of the NOPHO-DB-SHIP consortium

INTRODUCTION

Pediatric acute myeloid leukemia (AML) is the second most common type of pediatric leukemia. Patients with AML are at high risk for several complications such as infections, typhlitis, and acute and long-term cardiotoxicity. Despite this knowledge, there are no definite supportive care guidelines as to what the best approach is to manage or prevent these complications.

AREA COVERED

The NOPHO-DB-SHIP (Nordic-Dutch-Belgian-Spain-Hong-Kong-Israel-Portugal) consortium, in preparation for a new trial in pediatric AML patients, had dedicated meetings for supportive care. In this review, the authors discuss the available data and outline recommendations for the management of children and adolescents with AML with an emphasis on hyperleukocytosis, tumor lysis syndrome, coagulation abnormalities and bleeding, infection, typhlitis, malnutrition, cardiotoxicity, and fertility preservation.

EXPERT OPINION

Improved supportive care has significantly contributed to increased cure rates. Recommendations on supportive care are an essential part of treatment for this highly susceptible population and will further improve their outcome.

Effectiveness and safety of leukapheresis in hyperleukocytic leukemias: a retrospective multicenter study

Leukapheresis is an effective adjuvant therapy for leukemia patients with hyperleukocytosis, but few studies have reported recent data with modern modalities and comparisons among different leukemia types. We conducted a retrospective study on leukapheresis among 420 patients with AML, ALL and CML in four local centers. WBC counts decreased significantly (p < 0.001) postleukapheresis in all three cohorts. Clearance efficiency was higher in acute leukemia patients than CML patients (p < 0.01). Concomitant leukocytoreduction drugs improved WBC reduction only in AML patients (p < 0.05). Leukocyte, hemoglobin and platelet levels preleukapheresis might affect the clearance efficiency in AML and/or ALL patients. Hematological toxicities were the major concerns, but most of them were mild, and only 11 patients died of all causes within one week postleukapheresis. In conclusion, leukapheresis can safely reduce the leukemic burden, especially for patients with acute leukemias.

Leukapheresis in Pediatric Acute Leukemia with Hyperleukocytosis: A Single-Center Experience

Hyperleukocytosis in pediatric acute leukemia is associated with increased morbidity and mortality and at present there is no consensus on the use of leukapheresis (LPH) for its management. Our aim was to review characteristics and outcomes of newly diagnosed leukemia patients with hyperleukocytosis (HL) comparing those who received LPH and those who did not. An IRB approved retrospective case control study reviewed data from a single institution over a 10 year period. At our institution, LPH was used in 8 of 62 (13%) patients with hyperleukocytosis with minimal complications. Mean leukocyte count in patients who received LPH versus those who did not was 498 k cells/mm³ and 237 k cells/mm³, respectively. Patients who had symptoms of neurologic (63 vs. 17%) or pulmonary leukostasis (75 vs. 17%) were more likely to have undergone leukapheresis. The time from presentation to the initiation of chemotherapy was not different between those who received LPH and those who did not (mean of 35 h vs. 34 h). There was one death in the LPH group, that was the result of neurologic sequelae of hyperleukocytosis and not LPH itself. The use of LPH in patients with hyperleukocytosis is safe, well tolerated and does not alter time to chemotherapy at our institution.

Therapeutic Leukapheresis in Pediatric Leukemia: Utilization Trend and Early Outcomes in a US Nationwide Cohort

Leukapheresis (LA) in pediatric leukemia is performed for leukostasis, a life-threatening emergency in the setting of extremely increased blast cell counts. The authors aimed to assess the epidemiology of pediatric leukemia who received LA. The authors reviewed US nationally representative admission records of patients less than 20 years of age in the Kids' Inpatient Database for the years 2000, 2003, 2006, 2009, 2012, and 2016. Incidence of new leukemia cases who underwent LA were calculated for the years 2009, 2012, and 2016. Cox and logistic regression analyses were performed to ascertain the risk factors for adverse outcomes. There were 526 admissions for pediatric patients with acute lymphoblastic leukemia (ALL) (n=328), acute myeloid leukemia (AML) (n=124), or chronic myeloid leukemia (CML) (n=74) who underwent LA over the study period. The incidence of leukemia cases that required LA was lower in 2016 than in 2009 or 2012 (1.4%, 2.2%, and 2.7%, respectively; P=0.001). In-hospital mortality was higher in AML than ALL (hzard ratio, 3.2; 95% confidence interval, 1.1-9.1). None with CML died during admission. This first population-based study of LA in pediatric leukemia showed a decreased utilization of LA over recent years. The higher inpatient mortality in AML, as compared with ALL or CML, warrant further investigations.

Pediatric Acute Myeloid Leukemia—Past, Present, and Future

This review reports about the main steps of development in pediatric acute myeloid leukemia (AML) concerning diagnostics, treatment, risk groups, and outcomes. Finally, a short overview of present and future approaches is given.

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.

Pediatric Emergency Medicine Didactics and Simulation (PEMDAS) Telesimulation Series: Hyperleukocytosis

INTRODUCTION

Hyperleukocytosis, an infrequent presentation of new-onset leukemia, is a medical emergency requiring prompt recognition and treatment. It can include altered mental status, fever, critical electrolyte derangements, and coagulopathies. Due to the COVID-19 pandemic, this simulation was created as a telesimulation in order to adhere to mandatory physical distancing guidelines while addressing learning objectives.

METHODS

This simulation was designed for pediatric emergency medicine fellows and featured a pediatric patient presenting with fever, altered mental status, and respiratory distress. After an initial assessment and appropriate workup, the patient developed tumor lysis syndrome, coagulopathies, and new-onset neurologic changes requiring appropriate interventions. A debriefing guide and participant evaluation form were utilized.

RESULTS

This telesimulation was implemented at five different institutions, with evaluation surveys completed by 22 pediatric emergency medicine fellows. The scenario was rated on a 5-point Likert scale (1 = strongly disagree, 5 = strongly agree) and was generally well received, with participants rating the simulation as effective in teaching the recognition (M = 4.8) and management (M = 4.6) of hyperleukocytosis. Participants felt that virtual telesimulation was effective compared to other distance learning methods (M = 3.9).

DISCUSSION

This simulation-based curriculum allows learners to practice identifying and managing hyperleukocytosis. We found that it was well received in both in-person and virtual formats.

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.

Therapeutic leukapheresis and thrombapheresis in medical emergencies

The management of hyperleukocytosis or thrombocytosis by therapeutic cytapheresis in the early 21 st century is far from codified (universal). Therapeutic cytapheresis have been proposed to achieve more rapid cytoreduction in peripheral blood than old universal support in order to quickly prevent potential complications. But, there are no randomized studies demonstrating the superiority of cytapheresis over other treatments alone. In this short review, based on our own experience (since 1980), we will give the indications and the role of cytapheresis procedures and we will try to answer the questions: when is therapeutic cytapheresis appropriate and do they still have a place in 2020, especially as a medical emergency?

Venous Thromboembolism After Peripherally Inserted Central Catheters Placement in Children With Acute Leukemia: A Single-center Retrospective Cohort Study

OBJECTIVE

To explore the incidence rate and characteristics of symptomatic venous thromboembolism (VTE) after peripherally inserted central catheters (PICC) placement in children with acute leukemia (AL).

METHODS

The authors performed a retrospective study aiming at children admitted to Pediatric Blood Diseases Center with a new diagnosis of AL and received a PICC insertion, collected the clinical materials of all venous thrombosis cases, and analyzed the incidence rate and characteristics in various types of AL.

RESULTS

From September 2007 to December 2018, a total of 2423 patients got PICCs at least once, of whom 29 patients experienced thrombosis events and the overall incidence rate of symptomatic VTE after PICC insertion was 1.2%. Deep venous thrombosis accounted for the majority with 75.9%. Seven cases of cerebral venous sinus thrombosis were documented and they all developed in patients with acute lymphoblastic leukemia (ALL). No pulmonary embolism was detected. Patients with acute myeloid leukemia (AML) had an identical risk of thrombosis to patients with acute lymphoblastic leukemia (ALL) (1.7% vs. 1.09%, P>0.05). All thrombi in patients with AML were located on the upper extremity, whereas in the ALL group about half of the thromboembolism developed in other locations. There were no statistical differences between patients in different clinical trials of the ALL group (0.7% vs. 1.6%, P>0.05).

CONCLUSIONS

The incidence rates of symptomatic VTE after PICC placement in children with AL in our center were relatively low and acceptable. For patients with AML, PICC placement plays the most important role in venous thrombosis. However, in patients with ALL, the potential risk factors were more complex.

Treatment Outcome in Pediatric Acute Lymphoblastic Leukemia With Hyperleukocytosis in the Yeungnam Region of Korea: A Multicenter Retrospective Study

Acute lymphoblastic leukemia (ALL) with hyperleukocytosis at diagnosis is associated with early morbidity and mortality due to complications of leukostasis. Of 535 pediatric ALL patients (January 2004 to December 2016 from the Yeungnam region of Korea), 72 (13.5%) patients with an initial white blood cell (WBC) count of ≥100×10/L were included in this study, of whom 38 patients had extreme hyperleukocytosis (WBC>200×10/L) at diagnosis. Fourteen patients (19.4%) had ≥1 early respiratory and neurologic complications during induction therapy. Relapse occurred in 8 patients (24.2%) with extreme hyperleukocytosis and in 1 patient (3.0%) with an initial WBC count of 100 to 200×10/L (P=0.012). Estimated 10-year event-free survival rate (EFS) and overall survival rate were 78.3%±8.4% and 82.6%±7.7%, respectively. The 10-year EFS was significantly lower in patients with an initial WBC count of >200×10/L than in those with an initial WBC count of 100 to 200×10/L (65.7%±13.4% vs. 91.2%±7.9%; P=0.011). The 10-year EFS and overall survival rate did not differ significantly between patients with extreme hyperleukocytosis who received hematopoietic stem cell transplantation and those who received chemotherapy. In conclusion, pediatric ALL with hyperleukocytosis can lead to early complications and mortality. Patients with initial extreme hyperleukocytosis showed significantly poorer prognosis than those with WBC counts of 100 to 200×10/L.

Leukocytapheresis for patients with acute myeloid leukemia presenting with hyperleukocytosis and leukostasis: a contemporary appraisal of outcomes and benefits

Introduction: Hyperleukocytosis, defined as a total white blood cell count (WBC) >50 or more commonly >100 × 10⁹ cells/L, is a presenting feature of acute myeloid leukemia (AML) in about 6-20% of cases and is associated with a higher risk of tumor lysis syndrome (TLS), disseminated intravascular coagulation (DIC), clinical leukostasis with end organ damage, and mortality.Areas covered: In this review, authors discuss the implications of hyperleukocytosis in AML and the current understanding of cytoreductive strategies with a focus on the use of leukocytapheresis.Expert commentary: Efforts to rapidly reduce peripheral myeloblasts have included the use of leukocytapheresis. Early studies demonstrated feasibility in reducing peripheral WBC and blast counts as well as clinically relevant patient outcomes which prompted its common use for many years. However, more recent data have directly challenged the previously touted reports of reduced TLS and DIC incidence as well as survival benefit, even in patients with clinical leukostasis. The use of leukocytapheresis remains highly controversial with wide practice variations among physicians, institutions, and countries given the lack of high-quality data, risks associated with leukocytapheresis itself, associated high costs, resource utilization, and lack of evidence-based clinical guidelines.

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.

Guidelines on the Use of Therapeutic Apheresis in Clinical Practice - Evidence-Based Approach from the Writing Committee of the American Society for Apheresis: The Eighth Special Issue

The American Society for Apheresis (ASFA) Journal of Clinical Apheresis (JCA) Special Issue Writing Committee is charged with reviewing, updating and categorizing indications for the evidence-based use of therapeutic apheresis (TA) in human disease. Since the 2007 JCA Special Issue (Fourth Edition), the committee has incorporated systematic review and evidence-based approaches in the grading and categorization of apheresis indications. This Eighth Edition of the JCA Special Issue continues to maintain this methodology and rigor in order to make recommendations on the use of apheresis in a wide variety of diseases/conditions. The JCA Eighth Edition, like its predecessor, continues to apply the category and grading system definitions in fact sheets. The general layout and concept of a fact sheet that was introduced in the Fourth Edition, has largely been maintained in this edition. Each fact sheet succinctly summarizes the evidence for the use of TA in a specific disease entity or medical condition. The Eighth Edition comprises 84 fact sheets for relevant diseases and medical conditions, with 157 graded and categorized indications and/or TA modalities. The Eighth Edition of the JCA Special Issue seeks to continue to serve as a key resource that guides the utilization of TA in the treatment of human disease.

Hyperleukocytosis in infant acute leukemia: a role for manual exchange transfusion for leukoreduction

BACKGROUND

Hyperleukocytosis is a serious, life-threatening complication of pediatric acute leukemia that can cause neurologic injury, pulmonary leukostasis, metabolic derangements, and coagulopathy. Acute leukemia has the highest risk of mortality and morbidity at presentation when associated with hyperleukocytosis. Infant leukemia presents unique challenges and treatment considerations due to the disease itself and size and overall health of the patient. While medical management of hyperleukocytosis in older patients with acute leukemia has been described, including cytoreductive procedures with automated leukapheresis (AL) or manual whole blood (WB) exchange transfusion, very little data exist for standardized management of hyperleukocytosis in infant leukemia patients.

CASE REPORTS

We describe four cases of infant acute leukemia presenting with hyperleukocytosis and leukostasis who each received manual WB exchange transfusions in conjunction with induction chemotherapy and review the existing literature on the use of procedural leukoreduction in infants with hyperleukocytosis. Special attention is given to challenges and technical aspects of leukapheresis in infants: when to perform manual WB exchange versus AL, optimal vascular access, blood product selection, exchange rates, and the monitoring for complications. Using published cases, we outline benefits versus risks of manual WB exchange and AL in infants less than 10 kg.

CONCLUSION

If providers perform procedural leukoreduction, the literature and our experience demonstrate manual WB exchange transfusion is favored over AL in infants less than 10 kg because of technical and complication risks associated with AL. Additional studies are needed to understand the impact of cytoreduction on long-term outcomes.

Leukemoid Reaction in Infant Pertussis: Is There a Place for Hydroxyurea? A Case Report

A 73-days old infant of 34 weeks' gestation was hospitalized with a co-infection of respiratory syncytial virus (RSV) and Bordetella pertussis (BP). She required invasive ventilation for 9 days in the context of malignant pertussis with persistent hypoxemia and hypercapnia secondary to a leukemoid reaction. Despite an increase of white blood cell (WBC) count up to 70 G/L and ensuing pulmonary hypertension, no hemodynamic compromise occurred. Without clear indication for leukapheresis nor exchange transfusion, an off-label treatment with hydroxyurea was given for 5 days with gradual decrease of WBC count, without any complication and hospital discharge on day 29. To our knowledge, no effective therapy for malignant pertussis has been described in the literature and complications are frequent with leukoreduction procedures. We discuss an alternative to invasive procedures in young infants to fulfill the need to decrease rapidly leukocyte counts in a leukemoid reaction associated with Bordetella pertussis infection. To our knowledge, hydroxyurea has never been used in malignant pertussis but is a well-known medication for oncologic and hematologic diseases such as acute myeloid leukemia or sickle cell anemia. Its effects in this setting are not well understood but the positive outcome in our patient supports the need for further studies.

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.

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.