Bleeding complications and coagulopathy in acute leukaemia

Exploration of rotational thromboelastometry (ROTEM) to characterize the coagulation profiles of newly diagnosed pediatric leukemia patients

BACKGROUND

Viscoelastic testing has been used in adult hematologic malignancies in conjunction with conventional coagulation tests (CCTs) to predict coagulopathies and tailor blood product replacement. However, there is a paucity of similar pediatric studies.

OBJECTIVES

Analyze and correlate leukemia-associated coagulopathy in newly diagnosed pediatric leukemia patients using CCT's and Rotational Thromboelastometry (ROTEM).

METHODS

Pediatric patients with newly diagnosed acute leukemia underwent testing with ROTEM and CCTs on days 0, 15 and 29 of induction chemotherapy.

RESULTS

Sixty-two patients were enrolled. At presentation, 54.8 % of patients had platelets <50 K/μL, 73 % had prolonged PT, 1.6 % had fibrinogen <150 mg/dL. Fifteen patients (24.2 %) had WHO grade 1 bleeding and two patients (3 %) had WHO grade 4 bleeding. EXTEM/INTEM values at presentation (day 0) reflected hypocoagulability, however FIBTEM revealed hypercoagulability. Patients showed a progressive hypocoagulability in all ROTEM assays by day 15 (day 0 vs day 15, p < 0.001), with improvement by day 29 (day 15 vs day 29, p < 0.001). Day 0 ROTEM parameters were comparable to day 29. Fibrinogen strongly correlated with ROTEM at all three time points (p < 0.0001), along with platelet count with moderate correlations (p < 0.001).

CONCLUSION

Fibrinogen and platelets appear to be the drivers of leukemia associated coagulopathy in the pediatric population, suggesting the utility of using CCTs and ROTEM in this population to better evaluate hemostatic function and guide blood product replacement.

Management of hemostatic complications in acute leukemia: Guidance from the SSC of the ISTH

Patients with acute leukemia frequently develop thrombocytopenia and hemostatic complications caused by coagulopathy. Coagulopathy complicates the management of these patients and can lead to significant morbidity and mortality. This guidance document aims to review and provide guidance on the management of hemostatic complications in adult patients with acute leukemia, addressing four main issues, including platelet transfusion, disseminated intravascular coagulation, L-asparaginase-related hypofibrinogenemia, and the use of antifibrinolytic agents.

Disseminated Intravascular Coagulation in Acute Leukemia at Presentation and During Induction Therapy

Between January 2001 and December 2003, 67 patients with acute leukemia were evaluated prospectively for hemostatic abnormality at presentation, of which 43 (64.2%) had acute lymphoblastic leukemia and 24 (35.8%) had acute myelogenous leukemia. At presentation, 27 patients (40.3%) had bleeding manifestations. Thrombocytopenia was present in 57 patients (85%), and 33(49.3%) had some abnormality of global coagulation markers. Disseminated intravascular coagulation was defined by International Society of Thrombosis and Hemostasis criteria. Disseminated intravascular coagulation was more often associated with bleeding manifestations in acute myelogenous leukemia cases than in acute lymphoblastic leukemia cases. Two patients presented disseminated intravascular coagulation on day 7 of chemotherapy, without any bleeding manifestations. Four of 15 evaluated cases who had a bleeding or infection complication after day 7 of induction therapy also had disseminated intravascular coagulation. It is recommended that all patients with leukemia be investigated for disseminated intravascular coagulation at presentation.

Haemostatic problems in acute promyelocytic leukaemia

Despite the development of highly effective treatment strategies for acute promyelocytic leukaemia around 10% of patients die in the presentation period as a consequence of the associated bleeding diathesis. The cause of the coagulopathy is complex resulting from a combination of tissue factor (TF) and cancer procoagulant (CP) induced disseminated intravascular coagulation, exaggerated fibrinolysis due predominantly to enhanced expression of annexin II on APL blast cell membranes and blast cell production of cytokines. All-trans retinoic acid (ATRA) has revolutionised the treatment of APL. When combined with chemotherapy long term survival rates of up to 80% can be achieved. Commencement of ATRA induces APL blast cell differentiation and is associated with a rapid resolution of the bleeding tendency through a combination of effects which include up regulation of thrombomodulin and down regulation of TF and CP production and cell surface expression of annexin II.

Risk score model for fatal intracranial hemorrhage in acute leukemia

To build a risk score (RS) model of fatal intracranial hemorrhage (FICH) in patients with acute leukemia, we retrospectively assessed risk factors in 792 patients newly diagnosed with acute leukemia, 41 of whom had analyzable FICH. We found that female gender (relative risk (RR) = 5.234, P<0.001), acute promyelocytic leukemia (RR = 4.057, P = 0.003), leukocytosis (RR = 3.301, P = 0.004), thrombocytopenia (RR = 3.283, P = 0.005) and prolonged prothrombin time (RR = 3.291, P = 0.016) were significantly associated with occurrence of FICH in multivariate analysis. To calculate RS for FICH, one point was assigned for each risk factor, making the RS between 0 and 5. The RS model segregated patients into three prognostic groups: a low-risk group (LRG) for RS of 0 or 1; an intermediate-risk group (IRG) for RS of 2 or 3; and a high-risk group (HRG) for RS of 4 or 5. Expectation of FICH was well correlated with risk groups (all P-values < 0.001). Overall survival was significantly shorter in the HRG compared with the LRG. The RS model we constructed to predict the occurrence of FICH will be verified through prospective studies.

Use of recombinant factor VIIa prior to lumbar puncture in pediatric patients with acute leukemia

The persistence of abnormal coagulation test results after standard treatment with fresh frozen plasma (FFP) poses significant problems in children with acute leukemia requiring a diagnostic lumbar puncture and intrathecal chemotherapy. We report the prophylactic use of a single dose of 90 microg/kg recombinant activated factor VII (rFVIIa) in three children and the rapid correction of abnormal coagulation test results previously not corrected by FFP. Administration of rFVIIa was useful in avoiding a delay of diagnostic lumbar punctures and intrathecal chemotherapy. Hemorrhagic complications and adverse effects of rFVIIa were not observed. Prospective evaluation of this indication and dose appears warranted. (c) 2005 Wiley-Liss, Inc.

Pseudoplatelets: a retrospective study of their incidence and interference with platelet counting

AIMS

Spurious platelet counts can be found in acute leukaemias, as a result of the fragmentation of blood cells. Microscopic examination of a blood smear should be performed to detect the presence of these so called pseudoplatelets. When present, the platelet count should be corrected because of the important clinical consequences that a lower platelet count may have in these patients.

METHODS

K(3)EDTA anticoagulated blood was measured on an automated blood cell counter, and a blood smear was made and stained according the May Grünwald-Giemsa method for microscopic observation. A 500 cell/particle differentiation was performed and the automated platelet count was corrected.

RESULTS

The incidence of pseudoplatelets in 169 patients with acute leukaemia was studied. Pseudoplatelets were detected in 43 patients (25.4%), and seven patients (4.1%) were re-classified as having a major bleeding risk (platelet count, < 15 x 10(9)/litre).

CONCLUSIONS

Platelets should be determined morphologically in patients with acute leukaemia and a routine screening method for the detection of pseudoplatelets should be developed.

Effects of high-dose methotrexate on the hemostatic system in childhood acute lymphoblastic leukemia

BACKGROUND

Thromboembolic and hemorrhagic complications are significant causes of death in patients with malignancy. These are well-known with the use of certain drugs. This study was planned to investigate whether there was any effect of high-dose methotrexate on the hemostatic system in childhood acute lymphoblastic leukemia.

PROCEDURE

To evaluate the hemostatic system, we investigated coagulation screening tests (prothrombin time, activated partial thromboplastin time, and fibrinogen), coagulation inhibitors (protein C, protein S, and antithrombin III), and fibrinolytic system (fibrin degradation products and tissue plasminogen activator). These parameters were measured in 35 cycles of high dose-methotrexate (3 g/m(2)) of 20 childhood acute lymphoblastic leukemia cases at baseline and on days 1 and 7 after the therapy.

RESULTS

We found that high-dose methotrexate administration adversely affected both the coagulation system (prolonged prothrombin time and activated partial thromboplastin time and decreased fibrinogen levels) and coagulation inhibitors (decreased protein C, protein S, antithrombin III) on day 1 after chemotherapy compared to the baseline values. The hemostatic parameters began to improve on day 7 after chemotherapy, except for fibrin degradation products. Tissue plasminogen activator levels were not changed with the therapy.

CONCLUSIONS

Coagulation cascade (prolonged prothrombin time and activated partial thromboplastin time and decreased fibrinogen) and coagulation inhibitors (decreased protein C, protein S, and antithrombin III levels) have been found to be affected by high-dose methotrexate therapy, but these transient changes did not cause clinical thromboembolic or hemorrhagic complications.

Assessment of coagulation disorders in patients with acute leukemia before and after cytostatic treatment

Coagulation disorders are often the reason for fatal bleeding in acute promyelocytic leukemia. Their occurrence as well as pathogenesis and prognostic significance in other subtypes of acute myelogenous leukemia and acute lymphoblastic leukemia is less known. Tests were carried out in 70 patients including 49 with AML and 21 with ALL. In all patients thrombin-antithrombin complexes (TAT), D-dimer (DD) and plasmin-antiplasmin complexes (PAP), antithrombin III activity, fibrinogen/fibrin degradation products, APTT and PT were determined. The tests were performed on diagnosis and after cytostatic treatment. The level of TAT, DD and PAP was elevated in 83% of the patients on diagnosis and in 90% after treatment. The highest values were observed in AML M3 patients. Among leukemic patients with normal levels of TAT, DD and PAP at diagnosis, cytostatic treatment had a negligible effect on the level of these markers. During remission the levels of these markers returned to the normal values while in patients without remission they were either elevated or returned to normal values. No correlation between the levels of activation markers and remission rate was reported. DIC was diagnosed in 13 patients including three after chemotherapy. The DIC was acute or subacute in AML and chronic in ALL patients. In the majority of acute leukemia patients there were already changes on diagnosis indicating coagulation activation. Except for AML M3, these usually had a subclinical course. The TAT, DD and PAP tests are not reliable markers of remission in acute leukemias.

Disseminated intravascular coagulation (DIC) in adult patients with acute leukaemia

In 71 patients with acute leukaemia admitted for remission induction, disseminated intravascular coagulation (DIC) was looked for in 50 patients and diagnosed in 10 (20%). Of 10 patients with acute lymphoblastic leukaemia, 3 had DIC, and of 40 patients with acute myeloblastic leukaemia, 7 had DIC. The presence of DIC was related to bleeding manifestations within the first 2 weeks. A haemorrhagic diathesis was present in all DIC patients: 4 had minor and 6 had major bleeding, i.e. WHO grade > or = 2. In addition to blood product support, most DIC patients were treated with low doses of heparin and tranexamic acid. In all DIC patients the haemorrhagic symptoms preceded the heparin administration. Among 40 screened patients without DIC, 17 patients had minor and 3 had major haemorrhagic manifestations. Thus, the proportion of patients with major bleeding was significantly greater among the DIC patients (6/10 vs 3/40, p < 0.001). In conclusion, DIC at presentation was associated with a significantly increased risk for severe haemorrhagic complications and should be looked for in adults with acute leukaemia.