Thrombosis in Leukemia: Incidence, Causes, and Practical Management

Ischemic Stroke as the Presenting Feature for Non-acute Promyelocytic Leukemia Variant of Acute Myeloid Leukemia: A Case Report

Acute myeloid leukemia (AML) patients encounter complications mainly due to their underlying disease or chemotherapy. Although they are at high risk for both hemorrhagic and thrombotic complications, thrombotic vascular complication as an initial manifestation is less common and rarely reported, especially in non-acute promyelocytic leukemia (non-APML). A 58-year-old female with no co-morbidity presented with fever, decreased appetite, headache, and weakness in her left upper and lower limbs. Laboratory findings showed hyperleukocytosis with 90% blast cells and thrombocytopenia (50,000/dl). While investigated and conservatively managed, she developed a seizure and loss of consciousness on the same day and was admitted to the intensive care unit. Computed tomography showed a massive right infarct in the middle cerebral artery territory with a significant midline shift. Flow cytometry indicated the diagnosis of non-APML; chemotherapy, platelet transfusion, unfractionated heparin, mechanical ventilation, and other supportive treatments were started. While managing this case, we faced challenges in decision-making on thrombolysis, craniotomy, and chemotherapy. The case highlights the salient points and dilemmas in managing such an acutely ill patient in critical care.

Machine learning algorithm as a prognostic tool for venous thromboembolism in allogeneic transplant patients

As a serious complication after allogenic hematopoietic stem cell transplantation (allo-HSCT), venous thromboembolism (VTE) is significantly related to increased nonrelapse mortality. Therefore distinguishing patients at high risk of death who should receive specific therapeutic management is key to improving survival. This study aimed to establish a machine learning-based prognostic model for the identification of post-transplantation VTE patients who have a high risk of death. We retrospectively evaluated 256 consecutive VTE patients who underwent allo-HSCT at our center between 2008 and 2019. These patients were further randomly divided into (1) a derivation (80%) cohort of 205 patients and (2) a test (20%) cohort of 51 patients. The least absolute shrinkage and selection operator (LASSO) approach was used to choose the potential predictors from the primary dataset. Eight machine learning classifiers were used to produce 8 candidate models. A 10-fold cross-validation procedure was used to internally evaluate the models and to select the best-performing model for external assessment using the test cohort. In total, 256 of 7238 patients were diagnosed with VTE after transplantation. Among them, 118 patients (46.1%) had catheter-related venous thrombosis, 107 (41.8%) had isolated deep-vein thrombosis (DVT), 20 (7.8%) had isolated pulmonary embolism (PE), and 11 (4.3%) had concomitant DVT and PE. The 2-year overall survival (OS) rate of patients with VTE was 68.8%. Using LASSO regression, 8 potential features were selected from the 54 candidate variables. The best-performing algorithm based on the 10-fold cross-validation runs was a logistic regression classifier. Therefore a prognostic model named BRIDGE was then established to predict the 2-year OS rate. The areas under the curves of the BRIDGE model were 0.883, 0.871, and 0.858 for the training, validation, and test cohorts, respectively. The Hosmer-Lemeshow goodness-of-fit test showed a high agreement between the predicted and observed outcomes. Decision curve analysis indicated that VTE patients could benefit from the clinical application of the prognostic model. A BRIDGE risk score calculator for predicting the study result is available online (47.94.162.105:8080/bridge/). We established the BRIDGE model to precisely predict the risk for all-cause death in VTE patients after allo-HSCT. Identifying VTE patients who have a high risk of death can help physicians treat these patients in advance, which will improve patient survival.

A prediction model for central venous catheter-related thrombosis in patients with newly-diagnosed acute myeloid leukemia: A derivation cohort analysis

BACKGROUND

Catheter-related thrombosis (CRT) is a common complication in cancer patients, that may lead to chemotherapy deferral, elevated risk for systemic infections and pulmonary embolism. This study aimed to assess CRT incidence and risk factors in newly-diagnosed acute myeloid leukemia (AML) patients and create predictive models potentially allowing to decrease CRT occurrence in this population.

METHODS

This retrospective single-center analysis included all AML patients treated at the Rambam Health Care Campus between 2006 and 2019. Patient clinical and laboratory data were collected to evaluate thrombosis occurrence and time from AML diagnosis to CRT development. Multivariate classification models were created using logistic regression (LR) and competing risk analyzes.

RESULTS

The final analysis included 632 newly-diagnosed AML patients (mean age 54 ± 15 years). CRT incidence was 10.1% [confidence interval (CI) 7.7-12.9%], median time from AML diagnosis to CRT was 12.5 days [interquartile range 6-30]. In an LR multivariate model, prior history of venous thromboembolism [adjusted odds ratio (AOR) 12.046, p < 0.0001], acute promyelocytic leukemia (APL) (AOR 2.824, p = 0.015), a high body mass index and initial platelet counts <100 × 10E9/L (AOR 1.059 and 0.546; p = 0.011 and 0.040, respectively) were significantly associated with high CRT risk. Analysis of 587 non-APL patients demonstrated comparable results, with CRT incidence of 9.3% (CI 7.0%-12.1%) and emergence of chronic obstructive pulmonary disease (COPD) as a novel significant co-factor (AOR 34.491, p = 0.004). In both models, the area under curve (AUC) was ≥70%.

CONCLUSIONS

Significant CRT risk factors defined using the created model could be used for identification of high-risk newly-diagnosed AML patients requiring CRT prophylaxis.

Outcomes of symptomatic venous thromboembolism after haploidentical donor hematopoietic stem cell transplantation and comparison with human leukocyte antigen-identical sibling transplantation

BACKGROUND

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is regarded as a curative therapy for majority of hematologic malignancies and some non-malignant hematologic diseases. Venous thromboembolism (VTE) has become increasingly recognized as a severe complication following allogeneic hematopoietic stem cell transplantation (allo-HSCT).

OBJECTIVES

To show the characteristics of VTE after haploidentical donor hematopoietic stem cell transplantation (HID-HSCT) and make comparisons with matched related donor HSCT (MRD-HSCT).

PATIENTS/METHODS

A retrospective nested case-control study design was used, cases with VTE and matched controls were selected, with 3534 patients underwent HID-HSCT and 1289 underwent MRD-HSCT.

RESULTS

During follow-up, 114 patients with VTE were identified. The incidence of VTE in HID-HSCT group was similar to that of MRD-HSCT group (2.4% versus 2.3%, P = 0.92). In HID-HSCT group, VTE occurred at a median time of 92.5 days, which was earlier than MRD-HSCT group (243.5 days). For HID-HSCT, advanced disease status, cardiovascular risk factors, acute graft-versus-host disease (aGVHD), and relapse were the independent risk factors for VTE. For MRD-HSCT, cardiovascular risk factors, aGVHD, and relapse were associated with VTE. Overall survival (OS) of patients following HID-HSCT and MRD-HSCT were similar, but the OS in patients with VTE was significantly lower than patients without VTE.

CONCLUSIONS

There was no statistical difference in the incidence of VTE after HID-HSCT compared with MRD-HSCT. The development of VTE adversely impacted the OS after allo-HSCT.

Management strategies and clinical outcomes of acute myocardial infarction in leukaemia patients: Nationwide insights from United States hospitalisations

BACKGROUND

Patients with leukaemia are at increased risk of cardiovascular events. There are limited outcomes data for patients with a history of leukaemia who present with an acute myocardial infarction (AMI).

METHODS

We queried the Nationwide Inpatient Sample (2004-2014) for patients with a primary discharge diagnosis of AMI, and a concomitant diagnosis of leukaemia, and further stratified according to the subtype of leukaemia. Multivariable logistic regression was conducted to identify the association between leukaemia and major acute cardiovascular and cerebrovascular events (MACCE; composite of mortality, stroke and cardiac complications) and bleeding.

RESULTS

Out of 6 750 878 AMI admissions, a total of 21 694 patients had a leukaemia diagnosis. The leukaemia group experienced higher rates of MACCE (11.8% vs 7.8%), mortality (10.3% vs 5.8%) and bleeding (5.6% vs 5.3%). Following adjustments, leukaemia was independently associated with increased odds of MACCE (OR 1.26 [1.20, 1.31]) and mortality (OR 1.43 [1.37, 1.50]) without an increased risk of bleeding (OR 0.86 [0.81, 0.92]). Acute myeloid leukaemia (AML) was associated with approximately threefold risk of MACCE (OR 2.81 [2.51, 3.13]) and a fourfold risk of mortality (OR 3.75 [3.34, 4.22]). Patients with leukaemia were less likely to undergo coronary angiography (CA) (48.5% vs 64.5%) and percutaneous coronary intervention (PCI) (28.2% vs 42.9%) compared with those without leukaemia.

CONCLUSION

Patients with leukaemia, especially those with AML, are associated with poor clinical outcomes after AMI, and are less likely to receive CA and PCI compared with those without leukaemia. A multi-disciplinary approach between cardiologists and haematology oncologists may improve the outcomes of patients with leukaemia after AMI.

Treatment of venous thromboembolism in acute leukemia: A systematic review

BACKGROUND

The safety and efficacy of venous thromboembolism (VTE) treatment in patients with acute leukemia (AL) are not well understood and the optimal treatment strategy is unclear.

METHODS

We conducted a systematic review of the literature aiming to identify observational studies and randomized trials describing treatment of VTE in the setting of AL including, acute myeloid leukemia (AML), acute promyelocytic leukemia (APL), and acute lymphoblastic leukemia (ALL). Due to the heterogeneity of findings, no meta-analysis was attempted.

RESULTS

A total of 13 observational studies (11 cohorts and 2 case-control) totaling 5359 participants were included. The number of patients with VTE among the total population was 304 (5.7%; 95% CI 5.1-6.3). In patients with VTE, 221 patients received treatment with anticoagulation using either of low-molecular-weight heparin, unfractionated heparin, and/or vitamin K antagonists. Most studies adjusted the anticoagulant dose based on platelet count. The reported recurrence rate ranged from 0 to 29% among different studies and varied according to the duration of anticoagulant treatment and follow up. Bleeding events were not uniformly reported but the total number was low among anti-coagulated patients.

CONCLUSION

There is a significant lack of data in this area with a high degree of heterogeneity in the choice of anticoagulant, dose adjustments for thrombocytopenia, and duration of anticoagulation. Further studies are required to develop guidelines and suggestions for treatment of VTE in AL.

Genetics of pleiotropic effects of dexamethasone

OBJECTIVES

Glucocorticoids such as dexamethasone have pleiotropic effects, including desired antileukemic, anti-inflammatory, or immunosuppressive effects, and undesired metabolic or toxic effects. The most serious adverse effects of dexamethasone among patients with acute lymphoblastic leukemia are osteonecrosis and thrombosis. To identify inherited genomic variation involved in these severe adverse effects, we carried out genome-wide association studies (GWAS) by analyzing 14 pleiotropic glucocorticoid phenotypes in 391 patients with acute lymphoblastic leukemia.

PATIENTS AND METHODS

We used the Projection Onto the Most Interesting Statistical Evidence integrative analysis technique to identify genetic variants associated with pleiotropic dexamethasone phenotypes, stratifying for age, sex, race, and treatment, and compared the results with conventional single-phenotype GWAS. The phenotypes were osteonecrosis, central nervous system toxicity, hyperglycemia, hypokalemia, thrombosis, dexamethasone exposure, BMI, growth trajectory, and levels of cortisol, albumin, and asparaginase antibodies, and changes in cholesterol, triglycerides, and low-density lipoproteins after dexamethasone.

RESULTS

The integrative analysis identified more pleiotropic single nucleotide polymorphism variants (P=1.46×10(-215), and these variants were more likely to be in gene-regulatory regions (P=1.22×10(-6)) than traditional single-phenotype GWAS. The integrative analysis yielded genomic variants (rs2243057 and rs6453253) in F2RL1, a receptor that functions in hemostasis, thrombosis, and inflammation, which were associated with pleiotropic effects, including osteonecrosis and thrombosis, and were in regulatory gene regions.

CONCLUSION

The integrative pleiotropic analysis identified risk variants for osteonecrosis and thrombosis not identified by single-phenotype analysis that may have importance for patients with underlying sensitivity to multiple dexamethasone adverse effects.

Thrombosis in adult patients with acute leukemia

PURPOSE OF REVIEW

Recent studies indicate that the risk of thrombosis in hematologic patients may be similar or even higher than that found in patients with solid tumors. However, available information about pathogenesis and incidence of thrombosis in acute leukemia is limited. This review focuses on mechanisms underlying thrombosis in acute leukemia and discusses recent literature data.

RECENT FINDINGS

In the last few years, proofs have been provided that leukemic cells release free prothrombotic products, such as micro-vesicles, tissue factors, circulating free DNA and RNA. Furthermore, leukemic blasts can activate the procoagulant population of platelets, which initiate and amplify coagulation, causing thrombosis. In addition to factors produced by acute leukemia itself, others concur to trigger thrombosis. Some drugs, infections and insertion of central venous catheter have been described to increase risk of thrombosis in patients with acute leukemia.

SUMMARY

Thrombosis represents a serious complication in patients affected by myeloid and lymphoid acute leukemia. A proper knowledge of its pathophysiology and of the predisposing risk factors may allow to implement strategies of prevention. Improving prevention of thrombosis appears a major goal in patients whose frequent conditions of thrombocytopenia impede an adequate delivery of anticoagulant therapy.

Laboratory characterization of leukemic cell procoagulants

BACKGROUND

In acute myeloid leukemias, there is an increased chance to develop thrombotic disorders. We hypothesized that in addition to leukemic promyelocytes, monocytic leukemia cells may also have a higher procoagulant activity.

METHODS

Fibrin formation was assessed by a one-stage clotting assay using a magnetic coagulometer. The thrombin generation test (TGT) of magnetically isolated normal human monocytes, intact leukemic cells and their isolated microparticles was performed by a fluorimetric assay. Phosphatidylserine (PS) expression of leukemic cells and microparticle number determinations were carried out by flow cytometry.

RESULTS

All cell lines displayed a significant procoagulant potential compared to isolated normal human monocytes. In the TGT test, the mean of lagtime and the time to peak parameters were significantly shorter in leukemic cells (3.9-4.7 and 9.9-10.3 min) compared to monocytes (14.9 and 26.5 min). The mean of peak thrombin in various monocytic leukemia cell lines was 112.1-132.9 nM vs. 75.1 nM in monocytes; however, no significant difference was observed in the ETP parameter. Factor VII-deficient plasma abolished all procoagulant activity, whereas factor XII-deficient plasma did not affect the speed of fibrin formation and thrombin generation but modulated the amount of thrombin. Factor XI-deficient plasma affected the time to peak values in one leukemic cell line and also attenuated peak thrombin. Leukemia cell-derived microparticles from all three cell lines exerted a procoagulant effect by significantly shortening the lagtime in TGT; there was a nonsignificant difference in case of ETP parameter.

CONCLUSIONS

All investigated monocytic leukemia cell lines exhibited significant thrombin generation. This phenomenon was achieved by the procoagulants on the surface of leukemic cells as well as by their microparticles.

[The incidence and risk factors of catheter-related-thrombosis during induction chemotherapy in acute lymphocytic leukemia children]

目的

分析初诊急性淋巴细胞白血病（ALL）诱导化疗期外周静脉穿刺中心静脉置管（PICC）患儿导管相关性血栓（CRT）的危险因素。

方法

收集2014年3月1日至2014年12月31日首都医科大学附属北京儿童医院血液肿瘤中心白血病病房行PICC置管的116例初诊ALL患儿临床资料。

结果

①PICC置管后第15天33例（28.4%）患儿发生CRT（CRT组），83例患儿未发生CRT（非CRT组）。②两组在性别、年龄分布、ALL危险度、免疫表型以及置管时两组血常规、凝血功能、是否合并感染、置管静脉方面差异无统计学意义，CRT组右侧置管比例高于非CRT组[75.8%（25/33）对55.4%（46/83），P=0.043]。③CRT组患者均无临床症状，置管第15天D-二聚体高于非CRT组[0.18（0.05~2.45）mg/L对0.11（0.01~5.34）mg/L，P=0.001]。④观察期中出现3例导管相关性并发症，均为导管相关性感染，其中2例并发CRT。⑤置管第33天CRT组26例患者复查B超，19例（73.1%）血栓缩小，6例（23.1%）无明显变化，1例（3.8%）增大。

结论

CRT是初诊ALL患儿诱导化疗期PICC置管的常见导管相关并发症，但症状出现较少，大部分血栓可自行缩小，右侧置管为CRT发生的危险因素；检测D-二聚体水平以及定期进行导管部位B超检查有助于及时发现CRT。