Successful treatment of disseminated intravascular coagulation by recombinant human soluble thrombomodulin in patients with acute myeloid leukemia

Clinical practice guidelines for management of disseminated intravascular coagulation in Japan 2024. Part 2: hematologic malignancy

Disseminated intravascular coagulation (DIC) associated with hematologic malignancies, particularly acute promyelocytic leukemia (APL), is characterized by marked fibrinolytic activation, which leads to severe bleeding complications. Therefore, appropriate diagnosis and management of DIC are crucial for preventing bleeding-related mortality. However, to date, no clinical guidelines have specifically addressed hematologic malignancy-associated DIC. Therefore, we developed diagnostic and management algorithms for DIC based on a systematic literature review. Notably, these guidelines recommend using the JSTH DIC diagnostic criteria (2017 version) or the former Ministry of Health and Welfare DIC diagnostic criteria (1983 version) to diagnose DIC. Furthermore, in the management of DIC, it is essential to treat the underlying disease through transfusion of platelet concentrates and fresh frozen plasma, if necessary. A systematic review of antifibrinolytic and anticoagulant therapies concluded that tranexamic acid therapy is not strongly recommended for patients with APL undergoing treatment with all-trans retinoic acid (Grade 1C). The use of recombinant thrombomodulin is weakly recommended (Grade 2B), whereas the use of other anticoagulants, including heparin and serine protease inhibitors, is weakly not recommended (Grade 2C). Therefore, we hope that these guidelines will help physicians find the best possible solutions in clinical practice.

A systematic review and meta-analysis of recombinant human soluble thrombomodulin for the treatment of DIC associated with hematological malignancies

BACKGROUND

Recombinant human soluble thrombomodulin (rhTM) is commonly used in Japan to treat disseminated intravascular coagulation (DIC), but its efficacy compared with other anticoagulants is unclear. We conducted a systematic review and meta-analysis to investigate this issue in DIC patients with hematological malignancies.

METHODS

We searched PubMed, Cochrane, and Scopus for prospective and retrospective studies evaluating the efficacy and safety of rhTM in DIC patients with hematological malignancies between April 2008 and April 2023. We performed a systematic review and meta-analysis evaluating recovery from DIC, hemorrhagic adverse events (AEs), and overall survival (OS).

RESULTS

We analyzed one prospective (64 patients) and seven retrospective studies (209 patients). Use of rhTM was associated with a higher rate of recovery from DIC (OR: 2.25 [1.09-4.63] and 1.98 [1.12-3.50] in prospective and retrospective studies, respectively; same order below) and fewer hemorrhagic AEs (OR: 0.83 [0.30-2.30] and 0.21 [0.08-0.57]). rhTM did not improve OS (OR: 1.06 [0.42-2.66] and 1.72 [0.87-3.39]), although the incidence of hemorrhagic death was lower in the rhTM group (0 of 94 patients).

CONCLUSION

Use of rhTM in patients with hematological malignancy-associated DIC is strongly expected to be effective and safe.

Acute promyelocytic leukemia with PML/RARA (bcr1, bcr2 and bcr3) transcripts in a pediatric patient

Patients with acute promyelocytic leukemia (APL) exhibit the t(15;17)(q24.1;q21.2) translocation that produces the promyelocytic leukemia (PML)/retinoic acid receptor α (RARA) fusion gene. Different PML breakpoints yield three alternative molecular transcripts, bcr1, bcr2 and bcr3. The present study reports the simultaneous presence of three PML/RARA transcripts in a pediatric female patient diagnosed with APL, according to the clinical characteristics, immunophenotype and karyotype of the patient. The simultaneous presence of the PML/RARA transcripts were detected using reverse transcription-quantitative PCR (RT-qPCR). This was confirmed with HemaVision-28N Multiplex RT-qPCR, HemaVision-28Q qualitative RT-qPCR and the AmpliSeq RNA Myeloid Panel. To the best of our knowledge, the pediatric patient described in the present study is the first case found to exhibit all three PML/RARA transcripts (bcr1, bcr2 and bcr3). Additionally, a microarray analysis was performed to determine the expression profile, potential predictive biomarkers and the implications of this uncommon finding. According to the information obtained from molecular monitoring, the results reported in the present study were associated with a good patient prognosis. In addition, upregulated genes that are rare in acute myeloid leukemia were identified, and these genes may be promising diagnostic biomarkers for further study. For example, CCL-1 is present in leukemic stem cells, causing treatment failure and relapse, and α- and β-defensins have been reported exclusively in chronic myeloid leukemia. However, the results of the present study confirmed that they may also be present in APL. Thus, these findings suggested a possible signaling pathway that involves the PML/RARA oncoprotein in APL.

Attempt for a Recombinant Thrombomodulin Alpha Treatment in a Rat Disseminated Intravascular Coagulation Model Using Yamakagashi (Rhabdophis tigrinus) Venom

Yamakagashi (Rhabdophis tigrinus) inhabits Japan widely, and incidents involving its bites occur every year. Its bite causes disseminated intravascular coagulation when the amount of infused venom is high, and it can be fatal if treatment with Yamakagashi antivenom is delayed. Although Yamakagashi antivenom is used for treating Yamakagashi bites, it is an unapproved drug and its capacity for storage is limited. Hence, it is difficult to administer to patients promptly. As a therapeutic agent for this bite, we investigated the application of recombinant thrombomodulin alpha, a commercially available disseminated intravascular coagulation therapeutic agent. Its therapeutic effect on Yamakagashi venom was confirmed in a coagulation system of human plasma using in vitro Yamakagashi venom as well as a rat experimental model of disseminated intravascular coagulation using in vivo Yamakagashi venom. The administration of recombinant thrombomodulin alpha induced an effect that prolonged the blood coagulation time of Yamakagashi venom in vitro, and the drug was administered in vivo within 0.5 h after the administration of Yamakagashi venom to save rats. Blood coagulation markers such as platelet count, prothrombin time, fibrinogen concentration, and D-dimer levels recovered to normal values in rats. Therefore, recombinant thrombomodulin alpha may be used as a therapeutic agent for Yamakagashi bites.

Diagnostic Scores and Treatment Options for Acute Disseminated Intravascular Coagulation in Children

Disseminated intravascular coagulation (DIC) is a thrombo-hemorrhagic condition that commonly accompanies life-threatening illnesses in children and is associated with significant morbidity and mortality. Treatment of underlying conditions, hemodynamic support, and replacement therapy with blood components is the mainstay of DIC management. Limited research studies have supported the use of antithrombin (AT), recombinant thrombomodulin (rTM), and protein C concentrates (PrCC). Although there have been several studies and advancements in the DIC treatment in adults, data in pediatric patients are limited, and the consensus is lacking. Evidence validating the use of diagnostic scoring systems in the pediatric population is also limited. Since the hemostatic system differs significantly in children, especially in neonates, management of DIC is also different in children from that of adults, and there is a dire need for good quality research studies in this aspect.

We reviewed more than 100 articles in PubMed, Cochrane database, and Google Scholar. This traditional review article discusses different scoring systems for diagnosing DIC in pediatric patients, and different pharmacological treatment options for acute DIC in this population. This study mainly focuses on papers published from 1990 to 2021 and includes papers in all languages involving humans only.

Coagulopathy in Acute Promyelocytic Leukemia: Can We Go Beyond Supportive Care?

Acute promyelocytic leukemia (APL) is characterized by frequent complications due to a distinct coagulopathy. While advances in treatments have improved long-term survival, hemorrhagic and thrombotic complications remain the most common causes of death and morbidity. Improved understanding of the mechanisms of the coagulopathy associated with APL may lead to therapeutic interventions to mitigate the risk of hemorrhage and thrombosis.

Hyperleukocytosis and Leukostasis in Acute Myeloid Leukemia: Can a Better Understanding of the Underlying Molecular Pathophysiology Lead to Novel Treatments?

Up to 18% of patients with acute myeloid leukemia (AML) present with a white blood cell (WBC) count of greater than 100,000/µL, a condition that is frequently referred to as hyperleukocytosis. Hyperleukocytosis has been associated with an adverse prognosis and a higher incidence of life-threatening complications such as leukostasis, disseminated intravascular coagulation (DIC), and tumor lysis syndrome (TLS). The molecular processes underlying hyperleukocytosis have not been fully elucidated yet. However, the interactions between leukemic blasts and endothelial cells leading to leukostasis and DIC as well as the processes in the bone marrow microenvironment leading to the massive entry of leukemic blasts into the peripheral blood are becoming increasingly understood. Leukemic blasts interact with endothelial cells via cell adhesion molecules such as various members of the selectin family which are upregulated via inflammatory cytokines released by leukemic blasts. Besides their role in the development of leukostasis, cell adhesion molecules have also been implicated in leukemic stem cell survival and chemotherapy resistance and can be therapeutically targeted with specific inhibitors such as plerixafor or GMI-1271 (uproleselan). However, in the absence of approved targeted therapies supportive treatment with the uric acid lowering agents allopurinol and rasburicase as well as aggressive intravenous fluid hydration for the treatment and prophylaxis of TLS, transfusion of blood products for the management of DIC, and cytoreduction with intensive chemotherapy, leukapheresis, or hydroxyurea remain the mainstay of therapy for AML patients with hyperleukocytosis.

Predictors of early death, serious hemorrhage, and differentiation syndrome in Japanese patients with acute promyelocytic leukemia

Significant advancements have been achieved with regard to the outcomes of acute promyelocytic leukemia (APL) patients through the introduction of all-trans retinoic acid; however, early hemorrhagic death and differentiation syndrome remain the major causes of remission induction failure in patients with APL. To investigate early death, serious hemorrhage, and differentiation syndrome during remission induction therapy in terms of incidence, risk factors, influence on outcomes, and prophylactic effects of several new anticoagulants, the results of 344 patients enrolled in the Acute Promyelocytic Leukemia 204 study conducted by the Japan Adult Leukemia Study Group were analyzed. Early death was observed in 16 patients (4.7%), of whom 14 had serious hemorrhage and 2 had differentiation syndrome. Serious hemorrhage and differentiation syndrome of grade 2 or higher were observed in 21 and 54 patients, respectively. Patients who achieved complete remission had a 7-year disease-free survival of 84.8% if they did not experience serious hemorrhage and 40.0% if they experienced serious hemorrhage during remission induction therapy (P = 0.001). Risk factor analyses showed that higher white blood cell count was associated with early death, higher white blood cell count and lower platelet count with serious hemorrhage, and leukocytosis during induction therapy and higher body surface area with differentiation syndrome. In conclusion, these results indicate that patients with such high-risk features may benefit from more intensive supportive care. The hemorrhagic risk was not relieved by the introduction of new anticoagulants. Further studies are required to establish the predictive impact of body surface area on differentiation syndrome. This trial is registered with UMIN-CTR as C000000154 on September 13, 2005.

High mobility group box 1 (HMGB1): a pivotal regulator of hematopoietic malignancies

High mobility group box 1 (HMGB1) is a nonhistone chromatin-associated protein that has been widely reported to play a pivotal role in the pathogenesis of hematopoietic malignancies. As a representative damage-associated molecular pattern (DAMP), HMGB1 normally exists inside cells but can be secreted into the extracellular environment through passive or active release. Extracellular HMGB1 binds with several different receptors and interactors to mediate the proliferation, differentiation, mobilization, and senescence of hematopoietic stem cells (HSCs). HMGB1 is also involved in the formation of the inflammatory bone marrow (BM) microenvironment by activating proinflammatory signaling pathways. Moreover, HMGB1-dependent autophagy induces chemotherapy resistance in leukemia and multiple myeloma. In this review, we systematically summarize the emerging roles of HMGB1 in carcinogenesis, progression, prognosis, and potential clinical applications in different hematopoietic malignancies. In summary, targeting the regulation of HMGB1 activity in HSCs and the BM microenvironment is highly beneficial in the diagnosis and treatment of various hematopoietic malignancies.

Analysis of the role of thrombomodulin in all-trans retinoic acid treatment of coagulation disorders in cancer patients

BACKGROUND

Clinical studies have shown that all-trans retinoic acid (RA), which is often used in treatment of cancer patients, improves hemostatic parameters and bleeding complications such as disseminated intravascular coagulation (DIC). However, the mechanisms underlying this improvement have yet to be elucidated. In vitro studies have reported that RA upregulates thrombomodulin (TM) expression on the endothelial cell surface. The objective of this study was to investigate how and to what extent the TM concentration changes after RA treatment in cancer patients, and how this variation influences the blood coagulation cascade.

RESULTS

In this study, we introduced an ordinary differential equation (ODE) model of gene expression for the RA-induced upregulation of TM concentration. Coupling the gene expression model with a two-compartment pharmacokinetic model of RA, we obtained the time-dependent changes in TM and thrombomodulin-mRNA (TMR) concentrations following oral administration of RA. Our results indicated that the TM concentration reached its peak level almost 14 h after taking a single oral dose (110 [Formula: see text]) of RA. Continuous treatment with RA resulted in oscillatory expression of TM on the endothelial cell surface. We then coupled the gene expression model with a mechanistic model of the coagulation cascade, and showed that the elevated levels of TM over the course of RA therapy with a single daily oral dose (110 [Formula: see text]) of RA, reduced the peak thrombin levels and endogenous thrombin potential (ETP) up to 50 and 49%, respectively. We showed that progressive reductions in plasma levels of RA, observed in continuous RA therapy with a once-daily oral dose (110 [Formula: see text]) of RA, did not affect TM-mediated reduction of thrombin generation significantly. This finding prompts the hypothesis that continuous RA treatment has more consistent therapeutic effects on coagulation disorders than on cancer.

CONCLUSIONS

Our results indicate that the oscillatory upregulation of TM expression on the endothelial cells over the course of RA therapy could potentially contribute to the treatment of coagulation abnormalities in cancer patients. Further studies on the impacts of RA therapy on the procoagulant activity of cancer cells are needed to better elucidate the mechanisms by which RA therapy improves hemostatic abnormalities in cancer.