ADAMTS-13 activity can predict the outcome of disseminated intravascular coagulation in hematologic malignancies treated with recombinant human soluble thrombomodulin

Thrombocytopenia-Associated Multiple Organ Failure

Thrombocytopenia-associated multiple organ failure is a clinical phenotype encompassing a spectrum of syndromes associated with disseminated microvascular thromboses. Autopsies performed in patients that died with thrombotic thrombocytopenic purpura, hemolytic uremic syndrome, or disseminated intravascular coagulation reveal specific findings that can differentiate these 3 entities. Significant advancements have been made in our understanding of the pathologic mechanisms of these syndromes. Von Willebrand factor and ADAMTS-13 play a central role in thrombotic thrombocytopenic purpura. Shiga toxins and the complement pathway drive the hemolytic uremic syndrome pathology. Tissue factor activity is vital in the development of disseminated intravascular coagulation.

Analysis of the association between resolution of disseminated intravascular coagulation (DIC) and treatment outcomes in post-marketing surveillance of thrombomodulin alpha for DIC with infectious disease and with hematological malignancy by organ failure

Background

Although disseminated intravascular coagulation (DIC) is life-threatening, any organ failure associated with DIC resolution and outcomes have been unclear.

Patients and methods

A total of 2795 DIC patients (infection: 1990, hematological malignancy: 805) were analyzed in the post-marketing surveillance of thrombomodulin alpha (TM-α). The background factors of sequential organ failure assessment (SOFA) and antithrombin (AT) were investigated in DIC with infectious disease for their association with DIC resolution and outcome using κ statistics, indicating DIC resolution and survival or DIC non-resolution and non-survival. The same analyses were performed for total bilirubin, creatinine, lactate dehydrogenase, and underlying disease in DIC with hematological malignancy.

Results

In DIC with infectious disease, higher SOFA score severity was closely correlated with lower overall survival in both the DIC resolution and non-resolution groups, but AT activity was not. κ coefficients were 0.234, 0.295, and 0.311 for the SOFA score 0-6, 7-12, and 13-24 groups, respectively. In DIC with hematological malignancy, κ coefficients of total bilirubin were 0.251 and 0.434, and those of creatinine were 0.283 and 0.437 in the normal and abnormal groups, respectively, showing better concordance in the abnormal group than in the normal. Other factors had poor concordance.

Conclusion

In DIC with infectious disease, DIC resolution is an important therapeutic target in patients who have higher SOFA score severity. In DIC with hematological malignancy, DIC resolution is similarly important in patients with abnormality of bilirubin and/or creatinine.

Trial registration

The clinical characteristics and treatment outcomes of patients with DIC treated with TM-α between May 2008 and April 2010 were retrospectively analyzed by subgroup analysis of the post-marketing surveillance data.

Levels and activities of von Willebrand factor and metalloproteinase with thrombospondin type-1 motif, number 13 in inflammatory bowel diseases

AIM

To evaluate the levels of von Willebrand factor (VWF) and metalloproteinase with thrombospondin type-1 motif, number 13 (ADAMTS13) in inflammatory bowel disease (IBD) and correlate them with the disease activity.

METHODS

Consecutive patients with IBD aged 18 years or older were enrolled in the study. Forty-seven patients with ulcerative colitis (UC), 38 with Crohn’s disease (CD), and 50 healthy controls were included. The white blood cell count, haematocrit, platelet count, fibrinogen, partial activated thromboplastin time, C-reactive protein, albumin, VWF antigen level (VWF:Ag), VWF ristocetin cofactor activity (VWF:RCo), VWF collagen-binding activity (VWF:CB), and ADAMTS13 antigen level (ADAMTS13:Ag) and activity (ADAMTS13act) were measured. The following ratios were assessed: VWF:RCo/VWF:Ag, VWF:CB/VWF:Ag, VWF:Ag/ADAMTS13act, and ADAMTS13act/ADAMTS13:Ag.

RESULTS

Compared to controls, the odds ratio (OR) of an elevated VWF: Ag > 150% was 8.7 (95%CI: 2.7-28.1) in the UC group and 16.2 (95%CI: 4.8-54.0) in the CD group. VWF:CB was lower in UC patients, and active CD was associated with a higher VWF: RCo (+38%). The ORs of VWF:CB/VWF:Ag < 0.7 (a marker of acquired von Willebrand syndrome) in the UC and CD groups were 11.9 (95%CI: 4.4-32.4) and 13.3 (95%CI: 4.6-38.1), respectively. Active UC was associated with lower ADAMTS13:Ag (-23%) and ADAMTS13act (-20%) compared to UC in remission. Patients with active CD had a 15% lower ADAMTS13act than controls. The activity of UC, but not that of CD, was inversely correlated with ADAMTS13:Ag (r = -0.76) and ADAMTS13act (r = -0.81).

CONCLUSION

Complex VWF-ADAMTS13-mediated mechanisms disturb haemostasis in IBD. A reduced WVF:CB is a risk factor for bleeding, while a lower ADAMTS13 level combined with an elevated VWF:Ag could predispose one to thrombosis.

Population pharmacokinetics of thrombomodulin alfa in pediatric patients with hematological malignancy and disseminated intravascular coagulation

BACKGROUND

Thrombomodulin alfa (TM-α) is a new class of anticoagulant drug for patients with disseminated intravascular coagulation (DIC). This study aimed to determine the pharmacokinetics of TM-α and determine the optimal dose in pediatric patients with hematological malignancy and DIC.

PROCEDURE

Pediatric patients with hematological malignancy and DIC were administered TM-α at a dose of 0.06 mg/kg (380 U/kg) over 30 min every 24 hr. Blood samples were taken at steady state before the start, immediately after the end, and 24 hr after the start of the sixth administration. Population pharmacokinetic analysis was performed using sparse samples with the nonlinear mixed-effect modeling program NONMEM^® , version 7.3.

RESULTS

The actual and predicted plasma concentrations of TM-α based on the final population pharmacokinetic model showed a good linear correlation. Clearance and volume of distribution of TM-α were affected by body weight. The clearance of TM-α in pediatric patients with hematological malignancy and DIC was higher than that in adults as previously reported. Six of eight patients did not achieve the target trough concentration at steady state. Furthermore, the pharmacokinetic simulation based on the estimated pharmacokinetic parameters from the final model demonstrated that TM-α administered at a dose of 0.06 mg/kg every 24 hr also failed to achieve the target trough concentration at steady state in the majority of pediatric patients.

CONCLUSIONS

Our study shows that further dose adjustment of TM-α is necessary considering the higher clearance per body weight in pediatric patients with hematological malignancy and DIC.

Decreased ADAMTS-13 level is related to inflammation factors and risk stratification of acute lymphoblastic leukemia patients

As a kind of metalloprotease of the ADAMTS family, ADAMTS-13 is crucial for maintaining the normal size of von Willebrand factor. Reduced ADAMTS-13 had been reported in patients with both localized and disseminated malignancies. However, the expression and potential role of ADAMTS-13 in hematological malignancies remain unclear. In this research, we measured and compared ADAMTS-13 levels in plasma of 35 acute lymphoblastic leukemia (ALL) patients and 30 healthy controls and found that ALL patients possessed lower level of ADAMTS-13 than controls. Correlations between ADAMTS-13 and inflammation factors were calculated and ADAMTS-13 was negatively correlated with C-reactive protein and interleukin-1β. ALL patients with infections had lower level of ADAMTS-13 than patients without infections. In addition, high-risk ALL patients possessed lower ADAMTS-13 than patients at low risk. To conclude, ADAMTS-13 level is decreased in the plasma of ALL patients and the level of ADAMTS-13 is related to plasma inflammation factors and risk stratification of ALL patients, which could contribute to better understanding of the clinical significance of ADAMTS-13.

Reduced ADAMTS-13 level negatively correlates with inflammation factors in plasma of acute myeloid leukemia patients

ADAMTS-13 is crucial for maintaining the normal size of vWF. Besides thrombotic thrombocytopenic purpura (TTP), decreased ADAMTS-13 had also been reported in patients with malignancy. However, the knowledge of expression and potential role of ADAMTS-13 in hematological malignancies is still limited. We measured and compared ADAMTS-13 levels in the plasma of 82 acute myeloid leukemia (AML) patients and 34 healthy controls and found that AML patients possessed lower ADAMTS-13 than controls. AML patients with infections possessed lower level of ADAMTS-13 than patients without infections and ADAMTS-13 levels were negatively correlated with C-reactive protein(CRP), IL-6, TNFα and IL-1β. Furthermore, high risk AML patients are with lower ADAMTS-13 than patients with low risk. ADAMTS-13 negatively correlated with ISTH scores and patients accompanying DIC possessed lower ADAMTS-13.Multivariate analyses proved that low level of ADAMTS-13 is an independent risk factor for AML outcome. To conclude, ADAMTS-13 levels are decreased in plasma of AML patients and the level of ADAMTS-13 is related to inflammation and infection of AML patients. Besides, low ADAMTS-13 level is one potential risk factor for AML patients.

Thrombocytopenia-Associated Multiple Organ Failure and Acute Kidney Injury

Thrombocytopenia-associated multiple organ failure (TAMOF) is a clinical phenotype that encompasses a spectrum of syndromes associated with disseminated microvascular thromboses, such as the thrombotic microangiopathies thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS) and disseminated intravascular coagulation (DIC). Autopsies findings in TTP, HUS, or DIC reveal specific findings that can differentiate these 3 entities. Von Willebrand factor and ADAMTS-13 play a central role in TTP. Shiga toxins and the complement pathway are vital in the development of HUS. Tissue factor is the major protease that drives the pathology of DIC. Acute kidney injury (AKI) is a common feature in patients with TAMOF.

Low ADAMTS-13 activity during hemorrhagic events with disseminated intravascular coagulation

Disseminated intravascular coagulation (DIC) is a life-threatening complication, and its control is essential for therapeutic success. Recombinant human soluble thrombomodulin alfa (rTM) is a novel therapeutic agent for DIC. The efficacy of rTM in the treatment of DIC is reportedly superior to that of conventional anti-DIC treatments, such as unfractionated heparin or low molecular weight heparin, but hemorrhagic events occasionally interfere with the therapeutic benefits of rTM. We assessed the clinical features of 20 consecutive patients who were given rTM for DIC associated with various hematologic disorders. Eight patients achieved remission of both primary disease and DIC, eight died due to progression of the primary disease, and four died of various hemorrhagic complications. Assessment of 16 biomarkers for coagulation showed that the four patients who died of hemorrhagic complications despite remission of their primary disease showed lower ADAMTS-13 (a disintegrin and metalloproteinase with a thrombospondin Type 1 motif, member 13) plasma activity than other patients (P = 0.016). The optimal cut-off level of ADAMTS-13 for predicting risk of hemorrhagic complications was 42 % (P = 0.007). Plasma ADAMTS-13 activity determined at diagnosis of DIC may help predict the risk of hemorrhagic events during and/or following DIC treatment with hematologic disorders.