Leukocyte count as a predictor of death during remission induction in acute myeloid leukemia

Acute myeloid leukemia: challenges for diagnosis and treatment in Latin America

OBJECTIVE

to review the current diagnostic and therapeutic landscape of AML in Latin America as a reflection of other low- and middle-income countries and regions of the world. Encompassing both acute promyelocytic and non-promyelocytic disease types.

METHODS

We reviewed the literature and study registries concerning epidemiological features of patients with AML/APL treated in Latin America, as well as evaluated diagnostic and genetic stratification and patient fitness assessment challenges, the importance of early mortality and supportive care capacity, intensive and non-intensive chemotherapy alternatives, consolidation, and maintenance strategies including novel agents and hematopoietic stem cell transplantation.

RESULTS

Although most of the current technologies and treatment options are available in the region, a significant fraction of patients have only limited access to them. In addition, mortality in the first weeks from diagnosis is higher in the region compared to developed countries.

CONCLUSIONS

Disparities in access to technologies, supportive care capacity, and availability of novel agents and HSCT hinder results in our region, reflecting barriers common to other LMICs. Recent developments in the diagnosis and treatment of this disease must be implemented through education, collaborative clinical research, and advocacy to improve outcomes.

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.

Survival Outcomes and Health-Related Quality of Life in Older Adults Diagnosed with Acute Myeloid Leukemia Receiving Frontline Therapy in Daily Practice

Acute myeloid leukemia has a poor prognosis in older adults, and its management is often unclear due to its underrepresentation in clinical trials. Both overall survival (OS) and health-related quality-of-life (HRQoL) are key outcomes in this population, and patient-reported outcomes may contribute to patient stratification and treatment assignment. This prospective study included 138 consecutive patients treated in daily practice with the currently available non-targeted therapies (intensive chemotherapy [IC], attenuated chemotherapy [AC], hypomethylating agents [HMA], or palliative care [PC]). We evaluated patients' condition at diagnosis (Life expectancy [Lee Index for Older Adults], Geriatric Assessment in Hematology [GAH scale], HRQoL [EQ-5D-5L questionnaire], and fatigue [fatigue items of the QLQ-C30 scale]), OS, early death (ED), treatment tolerability (TT) and change in HRQoL over 12 months follow-up. The median OS was 7.1 months (IC not reached, AC 5.9, HMA 8.8, and PC 1.0). Poor risk AML category and receiving just palliative care, as well as a higher Lee index score in the patients receiving active therapy, independently predicted a shorter OS. The Lee Index and GAH scale were not useful for predicting TT. The white blood cell count was a valid predictor for ED. Patients' HRQoL remained stable during follow-up.

Influence on therapeutic outcome of platelet count at diagnosis in patients with de novo non-APL acute myeloid leukemia

BACKGROUND

Platelet (PLT) count at diagnosis plays an important role in cancer development and progression in solid tumors. However, it remains controversial whether PLT count at diagnosis influences therapeutic outcome in patients with non-acute promyelocytic leukemia (APL) acute myeloid leukemia (AML).

METHODS

This study analyzed the relationship between PLT count at diagnosis and genetic mutations in a cohort of 330 newly diagnosed non-APL AML patients. The impact of PLT count on complete remission, minimal residual disease status and relapse-free survival (RFS) were evaluated after chemotherapy or allogeneic hematopoietic stem cell transplantation (allo-HSCT).

RESULTS

Our studies showed that patients with DNMT3A mutations have a higher PLT count at diagnosis, while patients with CEBPA biallelic mutations or t(8;21)(q22; q22) translocation had lower PLT count at diagnosis. Furthermore, non-APL AML patients with high platelet count (> 65 × 109/L) at diagnosis had worse response to induction chemotherapy and RFS than those with low PLT count. In addition, allo-HSCT could not absolutely attenuated the negative impact of high PLT count on the survival of non-APL AML patients.

CONCLUSION

PLT count at diagnosis has a predictive value for therapeutic outcome for non-APL AML patients.

A Survival Analysis of Acute Myeloid Leukemia Patients Treated With Intensive Chemotherapy: A Single Center Experience

INTRODUCTION

Acute myeloid leukaemia (AML) is a haematological disease associated with a dismal prognosis, despite major progress made in recent years in terms of antileukemic agents and supportive care.

METHODS

We investigated the results of the intensive treatment of 133 fit AML patients (de novo and secondary) from a referral cancer centre in Romania, treated between January 2015 and December 2021.

RESULTS

We included 79 male and 54 female patients with a median age of 53 years (range 18-70). Molecular biology analysis was available for 82.7% of patients, whereas karyotype analysis was only available for 33% of patients. The median overall survival (OS) was 8.7 months, and the disease-free survival rate was 26.3% at a median follow-up of 33.7 months. The complete remission (CR) rate after induction was 48.9% for all patients and 61.9% for patients who were assessable (excluding patients who died before being assessed for response). Twelve patients underwent allogeneic bone marrow transplantation (BMT), with the median OS not reached. Early mortality (EM), defined as death during the first 30 days after admission, was 17.3%, with the main cause of death being septic shock (78.3%). Elderly patients (≥60 years of age) had a lower OS, more primary refractory disease, and higher rates of early mortality.

CONCLUSION

Complete remission rates and OS in our cohort were lower than in other reports. Early mortality was unexpectedly high, mainly due to infections, which were the main causes of death in our cohort.

Urgent cytoreduction for newly diagnosed acute myeloid leukemia patients allows acquisition of pretreatment genomic data and enrollment on investigational clinical trials

Newly diagnosed acute myeloid leukemia is often deemed a medical emergency, requiring urgent treatment. This is in contradiction with the need for accurate cytogenetic and molecular data, which is not immediately available, to select optimal therapy. We hypothesized that cytoreduction with hydroxyurea or cytarabine would enable urgent disease control and provide a bridge to clinical trial enrollment. We analyzed three prospective frontline clinical trials that allowed the use of cytoreduction before treatment initiation. Among 274 patients with a median age of 62 (range, 18-89), there was no significant difference in short- and long-term outcome and safety among patients who did (CytoRed) or did not receive (NoCytoRed) cytoreduction. The overall response rate in CytoRed group was 91%, compared with 86% in NoCytoRed group (p = .264). The 30- and 60-day mortality rates were 2% and 7% in CytoRed group, compared with 2% (p = .978) and 6% (p = .652) in NoCytoRed group, respectively. There was no significant difference in overall survival (OS) between in CytoRed group compared with NoCytoRed group (Hazard ratio 0.97, 95% CI 0.70-1.37, p = .879). Results were unchanged after stratification by age (< or ≥65 years) or after multivariate analyses for OS. Our data suggests that urgent cytoreduction using hydroxyurea or cytarabine is a feasible and safe approach to facilitate acquisition of complete diagnostic information prior to treatment initiation on a clinical trial.

A novel upregulated LncRNA-AC026150.8 promotes chemo-resistance and predicts poor prognosis in acute myeloid leukemia

BACKGROUND

AML is a common hematological malignancy with poor prognosis, the pathogenesis is still unclear. lncRNA takes part in occurrence and development of AML. This research aims to explore new differentially expressed lncRNAs and their effects on AML.

METHODS

Database-based bioinformatics analysis was performed to screen differentially expressed lncRNA in AML, real-time PCR was used to analyze gene expression. Kaplan-Meier survival analysis was performed to determine prognostic effect of AC026150.8 in AML. The cell drug resistance experiment was performed to test effect of AC026150.8 on chemo-resistance of AML cells. Catrapid online software and RNA pull-down, mass spectrometry, western-blot were used to predict and verify the combination of AC026150.8 and RNA splicing factors.

RESULTS

AC026150.8 was upregulated in AML patients and related to poor prognosis. High leukocyte counts, FAB classification, MLL-AF9 expression and NPM1 mutations were associated with high AC026150.8 expression. Upregulated of AC026150.8 increased the drug resistance of AML cells. AC026150.8 could be combined with splicing factor PCBP1.

CONCLUSIONS

For the first time, our study found that the upregulated AC026150.8 in AML is related to poor prognosis, overexpression of AC026150.8 could increase drug resistance of AML cells, and confirmed its scaffolding effect in combination with splicing factors. It is necessary to further study AC026150.8 and its downstream target genes to clarify the mechanism of AC026150.8 in AML.

Effect of prophylactic leukapheresis on early mortality and overall survival in acute leukemia patients with hyperleukocytosis

Hyperleukocytosis has been associated with early mortality owing to the presence of complications including leukostasis, tumor lysis syndrome (TLS), and disseminated intravascular coagulation (DIC). Leukapheresis is a fast and effective cytoreductive procedure that removes leukocytes from the peripheral circulation. This single-center, retrospective, and observational study included 32 patients diagnosed with acute leukemia who underwent leukapheresis due to hyperleukocytosis between 2014 and 2020. This study primarily aimed to investigate the effect of prophylactic leukapheresis on early mortality and overall survival (OS). In the symptomatic group, seven and two patients died in the first and second weeks, respectively. In the prophylactic leukapheresis group, two and one patients died in the first and second weeks (p = 0.792), respectively. OS was significantly longer in the prophylactic leukapheresis group (p = 0.004). The leukapheresis procedure appears to be effective on early mortality and OS. Initiation of prophylactic leukapheresis before the appearance of leukostasis symptoms is effective on OS and possibly early mortality.

The factors influencing clinical outcomes after leukapheresis in acute leukaemia

Leukapheresis is used for the mechanical removal of leukaemic cells in hyperleukocytosis. However, the effectiveness of leukapheresis remains unclear due to selection and confounding factors in the cohorts. We compared the effectiveness of leukapheresis among the subgroups according to either the 2016 World Health Organization classification or the number of cytogenetic abnormalities with a retrospective, single-centre study from January 2009 to December 2018. Acute myeloid leukaemia (AML, n = 212) and acute lymphoblastic leukaemia (ALL, n = 97) were included. The 30-day survival rates (95% confidence interval, 95% CI) for AML and ALL were 86.3% (81.6–90.9%) and 94.8% (90.3–99.2%), respectively. For AML, ‘primary AML with myelodysplasia-related changes’ and ‘AML with biallelic mutation of CEBPA’ showed better 30-day survival outcomes (P = 0.026) than the other subgroups. A higher platelet count after leukapheresis was associated with better 30-day survival in AML patients (P = 0.029). A decrease in blast percentage count after leukapheresis was associated with better 30-day survival in ALL patients (P = 0.034). Our study suggested that prophylactic platelet transfusion to raise the platelet count to 50 × 10⁹/L or greater might improve clinical outcome in AML patients undergoing leukapheresis.

FLT3-ITD Mutation and FLT3 Ligand Plasma Level Were Not Associated with One-Year Survival of Indonesian Acute Myeloid Leukemia Patients

OBJECTIVE

To analyze the association of FLT3-ITD mutation and FLT3 ligand plasma level with one-year survival of Indonesian acute myeloid leukemia (AML) patients.

METHODS

A prospective cohort study was conducted to determine the association between FLT-3-ITD mutation and FLT3 ligand plasma level with one-year survival of Indonesian AML patients. In the study, a total of 51 AML patients were obtained from two tertiary hospitals in Indonesia from year 2018 to 2020. Inclusion criteria were de novo AML male and female patients aged ≥18 years old. Exclusion criteria were prior myelodysplastic syndrome and patients that refused to participate in the study. FLT3-ITD genotype of patients was then analyzed using PCR method while FLT3 ligand plasma level was measured using ELISA method. Patients were then followed-up for 1 year or until death occurred with survival as the measured outcome. Association between independent and dependent variable were analyzed by cox regression proportional hazard.

RESULTS

Eleven patients (21.5%) in this study had FLT3-ITD mutation. The median age of AML patients was 45 (18-71) years, and the median blast percentage was 50% (5-87%). After one-year follow-up, 33 (64.7%) patients had died. The median survival of AML patients was 6 months. Univariate analysis showed no association between FLT3-ITD mutation status (HR: 1.051 ; 95% CI: 0.483-2.286; P: 0.901) and FLT3 ligand plasma level (HR: 0.798; 95% CI: 0.347-1.837; p= 0.596), and age (HR: 1.283; 95% CI: 0.575-2.862; p= 0.542) with one-year survival of AML patients, but multivariate analysis showed association between GFR with one-year survival of AML patients in this cohort (HR: 4.053; 95% CI: 1.469-11.183; p= 0.007).

CONCLUSION

One-year survival of AML patients in Indonesia is not affected by FLT3-ITD mutation and FLT3 ligand plasma level. However, GFR showed association with one-year survival of AML patient in this cohort study.

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.

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.

Management of hyperleukocytosis and impact of leukapheresis among patients with acute myeloid leukemia (AML) on short- and long-term clinical outcomes: a large, retrospective, multicenter, international study

Hyperleukocytosis in acute myeloid leukemia (AML) is associated with inferior outcomes. There is limited high quality evidence to support the benefits of leukapheresis. We retrospectively collected data from patients with newly-diagnosed AML who presented with a white cell count (WBC) >50×10⁹/L to 12 centers in the United States and Europe from 2006–2017 and received intensive chemotherapy. Logistic regression models estimated odds ratios for 30-day mortality and achievement of composite complete remission (CRc). Cox proportional hazard models estimated hazard ratios for overall survival (OS). Among 779 patients, clinical leukostasis was reported in 27%, and leukapheresis was used in 113 patients (15%). Thirty-day mortality was 16.7% (95%CI:13.9–19.3%). Median OS was 12.6 months (95%CI:11.5–14.9) among all patients, and 4.5 months (95%CI: 2.7–7.1) among those ≥65 years. Use of leukapheresis did not significantly impact 30-day mortality, achievement of CRc, or OS in multivariate analysis based on available data or in analysis based on multiple imputation. Among patients with investigator-adjudicated clinical leukostasis, there were statistically significant improvements in 30-day mortality and OS with leukapheresis in unadjusted analysis, but not in multivariate analysis. Given the significant resource use, cost, and potential complications of leukapheresis, randomized studies are needed to evaluate its value.

The risk of early mortality in elderly patients with newly diagnosed acute myeloid leukemia

Background

Acute myeloid leukemia (AML) is a common hematologic neoplasm with high incidence and mortality in the elderly. Our aims were to explore risk factors for early mortality in elderly AML patients and develop a new prognostic score.

Methods

We enrolled newly diagnosed AML patients age 60 and above at Taipei Veterans General Hospital between July 2008 and May 2017. The primary endpoint was early mortality, defined as death within two months after AML diagnosis. A multivariate Cox proportional hazards model was used to build a risk‐scoring system incorporating significant risk factors for AML.

Results

The final cohort included 277 elderly AML patients. The median age was 74 (range 60‐96), and 61.7% were male. The two‐month mortality rate was 29.9%. Age ≥ 80 (adjusted HR 1.88), myocardial infarction (adjusted HR 1.87), ECOG ≥ 2 (adjusted HR 2.10), complex karyotype (adjusted HR 3.21), bone marrow blasts ≥ 70% (adjusted HR 1.88), WBC ≥ 100 × 10⁹/L (adjusted HR 3.31), and estimated glomerular filtration rate (eGFR) < 45 (adjusted HR 2.60) were identified as independent predictors for early mortality in the multivariate analysis. A simplified score incorporating the seven factors was developed with good predictive ability measured by Harrell's C statistic [0.72 (95% CI 0.66‐0.78)].

Conclusions

We identified seven potential risk factors for early mortality and built up a new prognostic score for elderly AML patients. The new score may help clinicians stratify patients and initiate appropriate management. Further validation of our findings on other cohorts is warranted.

Hemostatic function in hyperfibrinolytic disseminated intravascular coagulation

BACKGROUND

Global hemostatic mechanism(s) in patients with disseminated intravascular coagulation (DIC) are poorly understood. There are few diagnostic criteria of DIC based on overall or global hemostatic mechanisms.

METHODS

We have assessed in detailed the dynamic global hemostatic changes using thrombin and plasmin generation assay (T/P-GA), clot fibrinolytic waveform analysis (CFWA) and not-activated rotational thromboelastometry (NATEM), in a young girl with DIC associated with acute myeloid leukemia (AML). The ratios of endogenous thrombin potential (T-EP) and plasmin lag time (P-LT) relative to normal plasma was sourced from pooled normal plasma from healthy volunteers on T/P-GA.

RESULTS

The inverse P-LT ratio prior to tranexamic acid (TXA) treatment was greater than the T-EP ratio (1.1-2.8 and 0.83-1.2, respectively). Significant reduction in inverse P-LT ratio (0.084-1.3) was observed after TXA treatment. The interval from clotting to the initiation of fibrinolysis (fibrinolysis lag time: FLT) in CFWA was significantly shorter than the control at onset (74.2-91.6 s vs 109 s), indicating enhanced fibrinolysis. Data from an adult with acute promyelocytic leukemia-associated DIC also supportively showed a high inverse P-LT ratio (2.1) and shortened FLT (83.7 s). The clotting time in patient whole blood using NATEM-mode during an episode of severe epistaxis markedly shortened beyond control, but returned to normal after the addition of an anti-tissue factor (TF) monoclonal antibody.

CONCLUSION

The release of intravascular TF contributed to sustained activation of coagulation and subsequent fibrinolytic activity in this patient with AML-associated DIC, and T/P-GA could provide better quantitative data than conventional assays in these circumstances.

Extramedullary relapses of acute leukemias after allogeneic hematopoietic stem cell transplantation: clinical features, cumulative incidence, and risk factors

The aim of this study was to evaluate extramedullary (EM) relapses and its features in an allogeneic hematopoietic stem cell transplantation (alloHSCT) cohort, which consisted of patients with acute leukemia and advanced-phase chronic myeloid leukemia. One hundred and twenty-eight alloHSCT patients transplanted between the years 2001 and 2014 were analyzed. EM relapses observed in acute lymphoblastic leukemia (ALL) were more frequent than that of in acute myeloid leukemia (AML) and CML, although calculation of cumulative risk incidence, BM relapse, EM relapse, and non-relapse mortality were considered as competing risks of each other. At the 60^th month, estimated CBMR and CEMR incidences were, respectively, 14.3 (5.1)% and 25.9 (6.6)% in ALL, 25.8 (5.9)% and 15.5 (4.8)% in AML, and 61.5 (16.5)% and 17.9 (13.4)% in CML. Among multiple parameters, the only type of conditioning regimen (p:0.046), EM involvement at diagnosis (p:0.009), and the presence of GVHD were found to be associated with EM relapse risk independently (p:0.045). Chronic GVHD and TBI-based regimens significantly decreased the EM relapse risk, whereas it was higher with Mel/Flu and its variants. In conclusion, EM relapse is not uncommon after alloHSCT. GVHD and TBI-based regimens may prevent this complication.

A hospital based retrospective study of factors influencing therapeutic leukapheresis in patients presenting with hyperleukocytic leukaemia

Therapeutic leukapheresis is a rapid and effective method to reduce early mortality of patients with hyperleukocytic leukaemia (HLL). However, few studies on factors influencing the efficiency have been reported. In this study, 67 cases who underwent leukapheresis were retrospectively analysed and factors related to the collection efficiency of leukapheresis (CE_WBC) were also evaluated. Paired t test showed that there was a significant decrease in statistics of white blood cell (WBC) counts after apheresis. The results of two independent samples nonparametric test suggested that WBC counts, platelet (PLT) counts, haematocrit (HCT), hemoglobin (HGB), serum chlorine (Cl) and globulin (GLB) before leukapheresis correlated with the CE_WBC. Multiple linear regression analysis with background stepwise variable selection indicated that only WBC and HCT before leukapheresis had an influence on CE_WBC significantly. Kaplan-Meier analysis and Cox regression model indicated that lymphocyte (LY) and mean corpuscular hemoglobin (MCH) pre-apheresis as independent factors significantly affected the prognostic survival of patients with HLL. Moreover, platelets and red blood cell were contaminated in the product of leukapheresis. It is an urgent problem to be solved in order to realise higher efficacy and higher purity of WBC collection to improve the survival of patients with HLL through optimising instruments.

Long term impact of hyperleukocytosis in newly diagnosed acute myeloid leukemia patients undergoing allogeneic stem cell transplantation: An analysis from the acute leukemia working party of the EBMT

Up to 20% of acute myeloid leukemia (AML) patients present initially with hyperleukocytosis, placing them at increased risk for early mortality during induction. Yet, it is unknown whether hyperleukocytosis still retains prognostic value for AML patients undergoing hematopoietic stem cell transplantation (HSCT). Furthermore, it is unknown whether hyperleukocytosis holds prognostic significance when modern molecular markers such as FLT3-ITD and NPM1 are accounted for. To determine whether hyperleukocytosis is an independent prognostic factor influencing outcome in transplanted AML patients we performed a retrospective analysis using the registry of the acute leukemia working party of the European Society of Blood and Marrow Transplantation. A cohort of 357 patients with hyperleukocytosis (159 patients with white blood count [WBC] 50 K-100 K, 198 patients with WBC ≥ 100 K) was compared to 918 patients without hyperleukocytosis. Patients with hyperleukocytosis were younger, had an increased rate of favorable risk cytogenetics, and more likely to be FLT3 and NPM1 mutated. In multivariate analysis, hyperleukocytosis was independently associated with increased relapse incidence (hazard ratio [HR] of 1.55, 95% confidence interval [CI], 1.14-2.12; P = .004), decreased leukemia-free survival (HR of 1.38, 95% CI, 1.07-1.78; P = .013), and inferior overall survival (HR of 1.4, 95% CI, 1.07-1.84; P = .013). Hyperleukocytosis retains a significant prognostic role for AML patients undergoing HSCT.

Azacitidine for Front-Line Therapy of Patients with AML: Reproducible Efficacy Established by Direct Comparison of International Phase 3 Trial Data with Registry Data from the Austrian Azacitidine Registry of the AGMT Study Group

We recently published a clinically-meaningful improvement in median overall survival (OS) for patients with acute myeloid leukaemia (AML), >30% bone marrow (BM) blasts and white blood cell (WBC) count ≤15 G/L, treated with front-line azacitidine versus conventional care regimens within a phase 3 clinical trial (AZA-AML-001; NCT01074047; registered: February 2010). As results obtained in clinical trials are facing increased pressure to be confirmed by real-world data, we aimed to test whether data obtained in the AZA-AML-001 trial accurately represent observations made in routine clinical practice by analysing additional AML patients treated with azacitidine front-line within the Austrian Azacitidine Registry (AAR; NCT01595295; registered: May 2012) and directly comparing patient-level data of both cohorts. We assessed the efficacy of front-line azacitidine in a total of 407 patients with newly-diagnosed AML. Firstly, we compared data from AML patients with WBC ≤ 15 G/L and >30% BM blasts included within the AZA-AML-001 trial treated with azacitidine ("AML-001" cohort; n = 214) with AAR patients meeting the same inclusion criteria ("AAR (001-like)" cohort; n = 95). The current analysis thus represents a new sub-analysis of the AML-001 trial, which is directly compared with a new sub-analysis of the AAR. Baseline characteristics, azacitidine application, response rates and OS were comparable between all patient cohorts within the trial or registry setting. Median OS was 9.9 versus 10.8 months (p = 0.616) for "AML-001" versus "AAR (001-like)" cohorts, respectively. Secondly, we pooled data from both cohorts (n = 309) and assessed the outcome. Median OS of the pooled cohorts was 10.3 (95% confidence interval: 8.7, 12.6) months, and the one-year survival rate was 45.8%. Thirdly, we compared data from AAR patients meeting AZA-AML-001 trial inclusion criteria (n = 95) versus all AAR patients with World Health Organization (WHO)-defined AML ("AAR (WHO-AML)" cohort; n = 193). Within the registry population, median OS for AAR patients meeting trial inclusion criteria versus all WHO-AML patients was 10.8 versus 11.8 months (p = 0.599), respectively. We thus tested and confirmed the efficacy of azacitidine as a front-line agent in patients with AML, >30% BM blasts and WBC ≤ 15 G/L in a routine clinical practice setting. We further show that the efficacy of azacitidine does not appear to be limited to AML patients who meet stringent clinical trial inclusion criteria, but instead appears efficacious as front-line treatment in all patients with WHO-AML.

Prognostic Parameters of Acute Myeloid Leukaemia at Presentation

INTRODUCTION

The treatment response and outcome in acute myeloid leukaemia (AML) is heterogeneous.

AIM

To analyze the prognostic parameters of AML at presentation.

METHODS

The total sample of 44 AML patients was analyzed on the basis of age <55 and ≥55 years, sex, WBC count <50x10/⁹/l and ≥50x10/⁹/l, the Hb concentration <100 g/l and ≥100 g/l, PLT count <100x10/⁹/l and ≥100x10/⁹/l, Karnofsky score <60% and >60%, cytogenetics, CD56 expression, morphological type and types of treatment (standard and reduced induction chemotherapy, high-dose chemotherapy/stem cell transplantation - autologous and HLA matched, related, allogeneic, together and separately).

RESULTS

The age <55 years, Karnofsky score >60% and standard induction chemotherapy statistically correlated with the higher complete remission (CR) rates, longer relapse free survival (RFS), lower relapse rate (RR), and longer overall survival (OS) (p<0.01). The difference in terms of CR and RR between the sexes were not statistically significant (p<0.05), however women had statistically lower OS comparing to men (9.71±4.54 months vs. 38.03±9.17 months) (p<0.01). WBC count ≥ 50x10/⁹/l and the Hb concentration <100 g/l statistically correlated with shorter OS (p<0.05), while the WBC count ≥50x10/⁹/l statistically correlated with shorter RFS (p<0.05). The PLT count <100x10/⁹/l and ≥100x10/⁹/l was not found as prognostically significant for CR, RR, RFS, and OS (p<0.05). In comparison to the standard induction chemotherapy, both types of high dose chemotherapy/stem cell transplantation (HDT/SCT) (10/22), together and separately, resulted in longer RFS, lower RR, and longer OS (p<0.05). The frequency of cytogenetic risk was intermediate 81.6%, unfavorable 13.2%, and favorable 5.3%, respectively. CD56 + expression statistically correlated with the lower PLT count, higher RR, shorter RFS, and shorter OS (p<0.05). Statistical analysis of the cytogenetic risk and morphological types of AML were not possible due to the small number of patients in stratified groups.

CONCLUSIONS

Female sex, the WBC count >50x10/⁹/l, the concentration of Hb <100 g/l, and CD56 + expression, at presentation of AML, should be considered as parameters of adverse risk, especially in latter decisions considering post-remission treatment with HDT/SCT.

Clinical impact of CD200 expression in patients with acute myeloid leukemia and correlation with other molecular prognostic factors

CD200, a protein belonging to the immunoglobulin superfamily, has been associated with a poor prognosis in lymphoproliferative disorders and in acute leukemia. We studied the expression of CD200 in a series of 244 patients with diagnosis of acute myeloid leukemia (AML), to evaluate its impact on outcome and its possible association with other known prognostic factors.

CD200 was found in 136/244 (56%) patients, in 41 of whom (30%) with high intensity of expression (MFI ≥ 11). CD200 was more frequent in secondary compared to de novo leukemia (p = 0.0006), in CD34 positive cases (p = 0.00001), in Bcl2 overexpressing cases (p = 0.01), in those wild-type Flt3 (p = 0.004) and with favorable or unfavorable compared to intermediate karyotype (p = 0.0003). CD200+ patients have a two-fold lower probability to attain complete remission, both in univariate (p = 0.006) and multivariate (p = 0.04) analysis. The negative impact of CD200 was found also in overall survival (p = 0.02) and was correlated with the intensity of expression of the molecule (p = 0.024). CD200 has an additive negative impact on survival in patients with unfavorable cytogenetic (p = 0.046) and in secondary leukemia (p = 0.05), and is associate with a worsening of outcome in patients with favorable biological markers, such as mutated NPM (p = 0.02), wild-type Flt3 (p = 0.034), negativity of CD34 (p = 0.03) and of CD56 (p = 0.03).

In conclusion, CD200 is emerging as both a prognostic factor and a potential target of novel therapeutic approaches for AML, aiming to reverse the “do not eat me” signal of CD200 or to manipulate the suppressive immune microenvironment induced by CD200 binding to its receptor.

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.

Leukostasis in adult acute hyperleukocytic leukemia: a clinician's digest

Leukostasis is a poorly understood and life-threatening complication of acute hyperleukocytic leukemia. The incidence of hyperleukocytosis and leukostasis differs among various subtypes of leukemias. While the pathophysiology of leukostasis is not fully understood, recent research has elucidated many novel pathways that may have therapeutic implications in the future. Respiratory and neurological compromise represents the classical clinical manifestations of leukostasis. If it is not diagnosed and treated rapidly, the one-week mortality rate is approximately 40%. Targeted induction chemotherapy is an important component of the successful treatment of leukostasis, although other modalities of cytoreduction are being used and investigated. Copyright © 2016 John Wiley & Sons, Ltd.

Pre-treatment with oral hydroxyurea prior to intensive chemotherapy improves early survival of patients with high hyperleukocytosis in acute myeloid leukemia

Acute myeloid leukemia with high white blood cell count (WBC) is a medical emergency. A reduction of tumor burden with hydroxyurea may prevent life-threatening complications induced by straight chemotherapy. To evaluate this strategy, we reviewed medical charts of adult patients admitted to our institution from 1997 to 2011 with non-promyelocytic AML and WBC over 50 G/L. One hundred and sixty patients were included with a median WBC of 120 G/L (range 50-450), 107 patients received hydroxyurea prior to chemotherapy, and 53 received emergency induction chemotherapy (CT). Hospital mortality was lower for patients treated with hydroxyurea (34% versus 19%, p = 0.047) even after adjusting for age (p < 0.01) and initial WBC count (p = 0.02). No evidence of any difference between treatment groups in terms of WBC decline kinetics and disease free survival (p = 0.87) was found. Oral hydroxyurea prior to chemotherapy seems a safe and efficient strategy to reduce early death of hyperleukocytic AML patients.

Acute Myeloid Leukemia in Adolescents and Young Adults Treated in Pediatric and Adult Departments in the Nordic Countries

BACKGROUND

Studies on adolescents and young adults with acute lymphoblastic leukemia suggest better results when using pediatric protocols for adult patients, while corresponding data for acute myeloid leukemia (AML) are limited.

PROCEDURE

We investigated disease characteristics and outcome for de novo AML patients 10-30 years old treated in pediatric or adult departments. We included 166 patients 10-18 years of age with AML treated according to the pediatric NOPHO-protocols (1993-2009) compared with 253 patients aged 15-30 years treated in hematology departments (1996-2009) in the Nordic countries.

RESULTS

The incidence of AML was 4.9/million/year for the age group 10-14 years, 6.5 for 15-18 years, and 6.9 for 19-30 years. Acute promyelocytic leukemia (APL) was more frequent in adults and in females of all ages. Pediatric patients with APL had similar overall survival as pediatric patients without APL. Overall survival at 5 years was 60% (52-68%) for pediatric patients compared to 65% (58-70%) for adult patients. Cytogenetics and presenting white blood cell count were the only independent prognostic factors for overall survival. Age was not an independent prognostic factor.

CONCLUSIONS

No difference was found in outcome for AML patients age 10-30 years treated according to pediatric as compared to adult protocols.

Nucleophosmin mutation in de-novo acute myeloid leukemia

OBJECTIVE

Acute myeloid leukemia (AML) with mutated nucleophosmin gene (NPM1) has distinctive clinical, hematological and molecular features, and is included as a provisional entity in 2008 World Health Organization classification. In this study, we analyzed the frequency and features of AML with mutated NPM1 in Indian patients.

METHODS

One-hundred consecutive patients of de-novo AML were evaluated for NPM1 mutation and their features were compared with unmutated NPM1 patients.

RESULTS

AML with mutated NPM1 was seen in 21% cases. There was female preponderance with median age of 51 years. Distinguishing Features in mutated group were less bleeding manifestations and bone pains; more lymphadenopathy; higher median total leukocyte and platelet count; less frequency of pancytopenia and more preserved megakaryocytes. Morphologically, cup-shaped nuclei in peripheral blood blasts correlated with NPM1 mutation (p <0.01), but not bone marrow blasts. Among the French-American-British subtypes, NPM1 mutation was seen in M1, M4 and M2 subtypes but not in M0 and M3. Immunophenotypically, there was statistically significant negativity for CD34, strong association with monocytic markers (especially CD11c), CD123 was seen at higher frequency and higher mean fluorescence intensity (MFI) values for CD33 were observed in mutated cases.

CONCLUSIONS

Important findings in this study that have not been highlighted in detail in previous studies in NPM1-mutated cases include less bleeding manifestations and bone pains, lower frequency of pancytopenia and more preserved magakaryocytes, higher CD123 expression and higher MFI values for CD33. Presence of blasts with cup-shaped nuclei correlated with NPM1 mutation.

Prognostic Relevance of Cytokine Receptor Expression in Acute Myeloid Leukemia: Interleukin-2 Receptor α-Chain (CD25) Expression Predicts a Poor Prognosis

A variety of cytokine/cytokine receptor systems affect the biological behavior of acute leukemia cells. However, little is known about the clinical relevance of cytokine receptor expression in acute myeloid leukemia (AML). We quantitatively examined the expression of interleukin-2 receptor α-chain (IL-2Rα, also known as CD25), IL-2Rβ, IL-3Rα, IL-4Rα, IL-5Rα, IL-6Rα, IL-7Rα, the common β-chain (βc), γc, granulocyte-macrophage colony-stimulating factor (GM-CSF)Rα, G-CSFR, c-fms, c-mpl, c-kit, FLT3, and GP130 in leukemia cells from 767 adult patients with AML by flow cytometry and determined their prevalence and clinical significance. All cytokine receptors examined were expressed at varying levels, whereas the levels of IL-3Rα, GM-CSFRα, IL-2Rα, γc, c-kit, and G-CSFR exhibited a wide spectrum of ≥10,000 sites/cell. In terms of their French-American-British classification types, GM-CSFRα and c-fms were preferentially expressed in M4/M5 patients, G-CSF in M3 patients, and IL-2Rα in non-M3 patients. Elevated levels of IL-3Rα, GM-CSFRα, and IL-2Rα correlated with leukocytosis. In patients ≤60 years old, higher levels of these 3 receptors correlated with poor responses to conventional chemotherapy, but only IL-2Rα was associated with a shorter overall survival. By incorporating IL-2Rα status into cytogenetic risk stratification, we could sort out a significantly adverse-risk cohort from the cytogenetically intermediate-risk group. Analyses with various phenotypical risk markers revealed the expression of IL-2Rα as an independent prognostic indicator in patients with intermediate-risk cytogenetics. These findings were not observed in patients >60 years old. Our results indicate that several cytokine receptors were associated with certain cellular and clinical features, but IL-2Rα alone had prognostic value that provides an additional marker to improve current risk evaluation in AML patients ≤60 years old.

Bone Marrow MicroRNA-335 Level Predicts the Chemotherapy Response and Prognosis of Adult Acute Myeloid Leukemia

The aim of this study was to investigate the role of microRNA-335 (miR-335) in determining the treatment response and prognosis in adult acute myeloid leukemia (AML) patients receiving the cytarabine (Ara-C)-based chemotherapy.A total of 204 adult AML patients were collected. The miR-335 levels in serum and bone marrow samples from these patients were determined. All patients received Ara-C-based standard induction chemotherapy regimens. The treatment response to Ara-C-based chemotherapy was evaluated. All patients were followed for prognostic analyses.The levels of miR-335 in bone marrow and serum samples from adult AML patients achieving complete response were significantly higher than those without. The serum miR-335 level was not associated with the chemotherapy response and prognosis in these AML patients. In contrast, high bone marrow miR-335 level was significantly associated with a poor treatment response and also predicted a worse prognosis indicated by the relapse-free survival and overall survival periods in adult AML patients receiving Ara-C-based chemotherapy.Our finding suggests that bone marrow miR-335 level may be used as a marker to predict the chemotherapy response and prognosis in adult AML patients.

High serum concentration of L-kynurenine predicts unfavorable outcomes in patients with acute myeloid leukemia

The immunomodulatory effects of indoleamine 2,3-dioxygenase (IDO) are ascribed to its ability to catalyze the breakdown of the L-tryptophan along the L-kynurenine pathway. Because blasts from patients with acute myeloid leukemia (AML) express IDO, the goal of this study was to investigate the role of L-kynurenine as a prognostic marker for AML. We enrolled 48 AML patients. L-kynurenine concentrations were measured by high-performance liquid chromatography. The median serum L-kynurenine level was 1.67 μM. There was no significant difference in the complete remission rate between patients with L-kynurenine < 2.4 (77%) and ≥ 2.4 μM (75%). However, 3-year overall survival (OS) rates were significantly better in patients with low L-kynurenine levels (76%) than in those with high L-kynurenine levels (11%) (p < 0.0001). Furthermore, in intermediate-risk cytogenetics patients, only L-kynurenine was significantly associated with OS (p < 0.005). Multivariate analyses revealed that L-kynurenine and high leukocyte count were independent prognostic factors.

Role of low dose cytarabine in elderly patients with acute myeloid leukemia: An experience

PURPOSE

To highlight the acceptable results seen after use of low dose cytarabine in elderly patients of acute myeloid leukemia (AML) with comorbidities.

MATERIALS AND METHODS

This was a prospective study carried on 30 newly diagnosed patients of AML over 60 years of age who were unfit for standard treatment regimens. We did not use azacytidine and decitabine in our patients because these therapeutic modalities being extremely costly and our patient affordability being poor. After taking patient consent and institutional ethical clearance these patients were treated with 20 mg/m(2) cytarabine subcutaneously in two divided doses 12 h apart for 4 days every week for 4 weeks which constituted a cycle before disease, re-assessment was done. A repeat cycle was administered where ever needed and after attainment of remission, we continued low dose cytarabine for 2 days/week as maintenance after complete or partial response was documented.

RESULTS

In our study, we found that around 20% of patients achieved complete remission and 30% partial remission. The remission rates were definitely influenced by counts at presentation, performance at presentation, comorbidities, underlying myelodysplastic syndrome and baseline cytogenetics.

CONCLUSION

Low dose cytarabine is effective treatment option for elderly patients with AML when standard treatment options are not warranted.

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.

Prognosis and monitoring of core-binding factor acute myeloid leukemia: current and emerging factors

Core-binding factor acute myeloid leukemia (CBF-AML) - including AML with t(8;21) and AML with inv(16) - accounts for about 15% of adult AML and is associated with a relatively favorable prognosis. Nonetheless, relapse incidence may reach 40% in these patients. In this context, identification of prognostic markers is considered of great interest. Due to similarities between their molecular and prognostic features, t(8;21) and inv(16)-AML are usually grouped and reported together in clinical studies. However, considerable experimental evidences have highlighted that they represent two distinct entities and should be considered separately for further studies. This review summarizes recent laboratory and clinical findings in this particular subset of AML and how they could be used to improve management of patients in routine practice.

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.

Intact expression status of RASSF1A in acute myeloid leukemia

As a typical tumor suppressor gene, transcriptional silencing of ras-association domain family 1, isoform A (RASSF1A) is caused by biallelic methylation or the condition that one allele is methylated and then the other allele lost by allelic loss, as second hit. RASSF1A is inactivated epigenetically and thus down-regulated in many solid tumors. In summary, for the first time, we analyzed the expression status of RASSF1A in a cohort of 56 de novo acute myeloid leukemia (AML) patients using quantitative real-time polymerase chain reaction. Results of our study indicate that patients with AML exhibited no differences in the RASSF1A gene expression comparing to normal controls. In conclusion, expression status of RASSF1A remained intact in our target samples, indicating that RASSF1A expression variation does not participate in the pathogenesis and the progression of AML.

The effect of volume replacement during therapeutic leukapheresis on white blood cell reduction in patients with extreme leukocytosis

BACKGROUND

Extreme leukocytosis, generally defined as a white blood cell (WBC) count of more than 100 × 10(9) /L consisting largely of blast cells, especially when accompanied by clinical signs and symptoms of leukostasis or hyperviscosity, often predicts a poor clinical outcome in patients with acute leukemia. In this study, we aimed to investigate the effect of volume replacement (VR) during therapeutic leukapheresis (TA) procedure on early mortality rate and WBC reduction.

STUDY DESIGN AND METHODS

We retrospectively analyzed 29 patients who underwent TA from 2007 to 2011. Fifteen of the patients underwent TA procedure with VR and 14 of the patients underwent TA procedure without VR.

RESULTS

WBC reduction was significantly higher in patients who underwent TA with VR (p < 0.001). Early mortality rate was significantly lower in leukemia patients who underwent TA with VR than in patients who underwent TA without VR (p < 0.01); early mortality rates were 6.7% for 7-day and 13.8% for 100-day survivals. The mortality rates in the TA without VR group, however, were 42.9 and 71.4% for 7- and 100-day survivals, respectively.

CONCLUSION

Decreased early mortality rate in TA with VR group may be associated with prompt reduction of WBCs achieved with TA with VR and may also be associated with removal of the cytokines related to leukostasis. TA with VR would give more time for induction chemotherapy and increased overall survival rate.

Update on optimal management of acute myeloid leukemia

Acute myeloid leukemia (AML) represents a malignant accumulation of immature myeloid cells in the marrow, presenting with impaired hematopoiesis and its attendant complications, including bleeding, infection, and organ infiltration. Chromosomal abnormalities remain the most powerful predictors of AML prognosis and help to identify a subgroup with favorable prognosis. However, the majority of AML patients who are not in the favorable category succumb to the disease. Therefore, better efforts to identify those patients who may benefit from more aggressive and investigational therapeutic approaches are needed. Newer molecular markers aim at better characterizing the large group of intermediate-risk patients and to identify newer targets for therapy. A group that has seen little improvement over the years is the older AML group, usually defined as age ≥ 60. Efforts to develop less intensive but equally efficacious therapy for this vulnerable population are underway.

Hyperleukocytosis and leukocytapheresis in acute leukaemias: experience from a single centre and review of the literature of leukocytapheresis in acute myeloid leukaemia

BACKGROUND

Hyperleukocytosis is usually defined as leukocyte count >100 × 10(9)  L(-1) and can be seen in newly diagnosed leukaemias. Hyperleukocytic leukaemia is associated with a risk of organ failure and early death secondary to leukostasis. Mechanical removal of leukocytes by the apheresis technique, leukocytapheresis, is a therapeutic option in these patients.

METHODS

During a 16-year period, 16 patients were treated with leukocytapheresis (35 apheresis procedures) for hyperleukocytosis/leukostasis. We present our experience, and in addition we review previous studies of hyperleukocytosis/leukocytapheresis in patients with acute myeloid leukaemia (AML).

RESULTS

We used a highly standardised approach for leukocytapheresis in leukaemia patients with hyperleukocytosis. The average leukocytapheresis number for each patient was 2·2 (range 1-6). Median leukocyte count before apheresis was 309 × 10(9)  L(-1) (range 104-935); the mean leukocyte count reduction was 71%, corresponding to a mean absolute reduction of 219 × 10(9)  L(-1). No serious side effects were seen during or immediately after apheresis.

CONCLUSIONS

The data suggest that our standardised technique for leukocytapheresis effectively reduced the peripheral blood leukaemia cell counts. Previous studies in AML also support the conclusion that this is a safe and effective procedure for the treatment of a potentially life-threatening complication, but apheresis should always be combined with early chemotherapy.

The development and validation of a decision-analytic model representing the full disease course of acute myeloid leukemia

BACKGROUND

The treatment of acute myeloid leukemia (AML) is moving towards personalized medicine. However, due to the low incidence of AML, it is not always feasible to evaluate the cost-effectiveness of personalized medicine using clinical trials. Decision analytic models provide an alternative data source.

OBJECTIVE

The aim of this study was to develop and validate a decision analytic model that represents the full disease course of AML.

METHODS

We used a micro simulation with discrete event components to incorporate both patient and disease heterogeneity. Input parameters were calculated from patient-level data. Two hematologists critically evaluated the model to ensure face validity. Internal and external validity was tested by comparing complete remission (CR) rates and survival outcomes of the model with original data, other clinical trials and a population-based study.

RESULTS

No significant differences in patient and treatment characteristics, CR rate, 5-year overall and disease-free survival were found between the simulated and original data. External validation showed no significant differences in survival between simulated data and other clinical trials. However, differences existed between the simulated data and a population-based study.

CONCLUSIONS

The model developed in this study is proved to be valid for analysis of an AML population participating in a clinical trial. The generalizability of the model to a broader patient population has not been proven yet. Further research is needed to identify differences between the clinical trial population and other AML patients and to incorporate these differences in the model.