Potential role of interleukin-1 as the trigger for diffuse intravascular coagulation in acute nonlymphoblastic leukemia

Acute cardiovascular complications of disseminated intravascular coagulation in acute myeloid leukemia

BACKGROUND

Disseminated intravascular coagulation (DIC) is a common complication of all leukemia subtypes, but it is an especially prominent feature of Acute Myeloid Leukemias (AML). DIC complicating AML can lead to a variety of complications, however, its association with acute cardiovascular complications has not been reported before.

METHODS

National Inpatient Sample Database was used to procure individuals with AML, and baseline demographics and comorbidities were collected using ICD-10-DM codes. Patients were stratified into those with and without DIC. Greedy propensity matching using R was performed to match the two cohorts in 1:1 ratio on age, gender, and fifteen other baseline comorbidities. Univariate analysis pre and post-match along with binary logistic regression analysis post-match were used to analyze outcomes.

RESULTS

Out of a total of 37,344 patients with AML, 996 had DIC. DIC patients were younger, predominantly males, and had lower prevalence of baseline cardiovascular comorbidities. DIC patients had statistically significant higher mortality (30.2 % vs 7.8 %), acute myocardial infarction (5.1 % vs 1.8 %), acute pulmonary edema (2.3 % vs 0.7 %), cardiac arrest (6.4 % vs 0.9 %), and acute DVT/PE (6.6 % vs 2.7 %). Logistic regression model after matching showed similar outcomes along with significantly higher rates of acute heart failure in DIC patients.

CONCLUSION

These findings highlight the importance of close cardiovascular monitoring and prompt recognition of complications in AML patients with DIC. The underlying mechanisms involve a complex interplay of procoagulant factors, cytokine release, and endothelial dysfunction. Further studies are needed to develop targeted interventions for prevention and management of these complications.

The Coagulopathy of Acute Promyelocytic Leukemia: An Updated Review of Pathophysiology, Risk Stratification, and Clinical Management

Acute promyelocytic leukemia (APL) has a well-established mechanism and a long-term prognosis that exceeds that of any other acute leukemia. These improving outcomes are due, in part, to all-trans retinoic acid (ATRA) and arsenic trioxide (ATO), two targeted and highly active agents in this disease. However, there remains a considerable morbidity and mortality risk in APL secondary to clinically significant hemorrhagic and/or thrombotic events. Prevention and treatment of these coagulopathic complications remain significant impediments to further progress in optimizing outcomes for patients with APL. Moreover, the relative rarity of APL hinders adequately powered randomized controlled trials for evaluating APL coagulopathy management strategies. This review draws from peer-reviewed works falling between initial descriptions of APL in 1957 and work published prior to January 2023 and provides an updated overview of the pathophysiology of hemorrhagic and thrombotic complications in APL, outlines risk stratification parameters, and compiles current clinical best practices. An improved understanding of the pathophysiologic mechanisms driving hemorrhage and thrombosis along with the completion of well-designed trials of management strategies will assist clinicians in developing interventions that mitigate these devastating complications in an otherwise largely curable disease.

Influence of cytokines on early death and coagulopathy in newly diagnosed patients with acute promyelocytic leukemia

Introduction

Acute promyelocytic leukemia (APL) is a subtype of acute myeloid leukemia (AML) with a better prognosis. But early death (ED) rate remains high. APL patients are simultaneously accompanied by coagulopathy and hyperinflammation at the onset. It is not known what effects cytokines have on ED and coagulopathy in these patients. Therefore, the purposes of this study are to explore the clinical differences between APL and other types of AML, the link between cytokines and coagulopathy in newly diagnosed APL, and their roles in the ED for APL.

Methods

This study retrospectively collected the information of 496 adult patients with AML (age ≥14 years at admission) newly diagnosed in the First People's Hospital of Yunnan Province between January 2017 to February 2022, including 115 APL patients. The difference of clinical manifestations between two groups [APL and AML (non-APL)] was statistically analyzed. Then, the factors affecting ED in APL patients were screened, and the possible pathways of their influence on ED were further analyzed.

Results

The results indicate APL at the onset have a younger age and higher incidence of ED and DIC than other types of AML. Intracranial hemorrhage (ICH), age, and PLT count are found to be independent factors for ED in newly APL, among which ICH is the main cause of ED, accounting for 61.54% (8/13). The levels of cytokines in newly APL are generally higher than that in AML (non-APL), and those in the group of ED for APL were widely more than the control group. IL-17A and TNF-β are directly related to the ED in newly APL, especially IL-17A, which also affects ICH in these patients. Moreover, the increase of IL-17A and TNF-β cause the prolongation of PT in APL patients, which reflected the exogenous coagulation pathway. However, they have no effect on APTT prolongation and FIB reduction. Thus, it is speculated that IL-17A leads to early cerebral hemorrhage death in newly APL by inducing tissue factor (TF) overexpression to initiate exogenous coagulation and further leading to excessive depletion of clotting factors and prolongation of PT.

Conclusions

In conclusion, compared with other types of AML, APL patients have a younger age of onset and high inflammatory state, and are more likely to develop into DIC and die early. Age, and PLT count at diagnosis are independent factors for ED of APL, especially ICH. IL-17A is confirmed to be an independent risk factor for ED and ICH of newly APL. Hence, IL-17A may serve as a predictor of ED in newly diagnosed APL patients, and controlling its expression probably reduce ED in these patients.

Thrombocytopenia in cancer patients

Thrombocytopenia is a frequent complication of cancer and its treatment. The causes of thrombocytopenia in cancer patients can be diverse and multifactorial. Systemic chemotherapy is the most frequent cause of thrombocytopenia. The degree and duration thrombocytopenia depends upon whether the chemotherapeutic treatment is myeloablative, as used in stem cell transplants, or non-myeloablative, as typically used in solid non-hematologic malignancies. Additional causes of significant thrombocytopenia include tumor involvement of bone marrow and spleen; microangiopathic disorders such as disseminated intravascular coagulation, thrombotic thrombocytopenic purpura or hemolytic uremia syndrome. Lymphoproliferative malignancies can also be associated with secondary immune thrombocytopenia. Due to the broad differential diagnosis associated with cancer related thrombocytopenia, a careful diagnostic evaluation is indicated. The goal of treatment should be to maintain a safe platelet count to allow effective treatment of the underlying malignancy, prevent bleeding complications and to minimize the use of platelet product transfusion.

Molecular basis for the diagnosis and treatment of acute promyelocytic leukemia

Acute promyelocytic leukemia is characterized by gene rearrangements that always involve the retinoic acid receptor alpha on chromosome 15. In the majority of patients t(15;17) is detected, which generates the promyelocytic leukemia gene/retinoic acid receptor alpha rearrangement. This rearrangement interacts with several proteins, including the native promyelocytic leukemia gene, thus causing its delocalization from the nuclear bodies, impairing its function. The immunofluorescence staining technique using the anti-PML antibody may be used to provide a rapid diagnosis and to immediately start therapy using all-trans retinoic acid. The experience of the International Consortium on Acute Promyelocytic Leukemia has demonstrated that early mortality was significantly reduced by adopting the immunofluorescence technique. All-trans retinoic acid combined with chemotherapy is the standard therapy; this promotes complete remission rates greater than 90% and cure rates of nearly 80%. However, early mortality is still an important limitation and hematologists must be aware of the importance of treating newly diagnosed acute promyelocytic leukemia as a medical emergency.

Pathogenesis and treatment of thrombohemorrhagic diathesis in acute promyelocytic leukemia

Acute promyelocytic leukemia (APL) is a distinct subtype of myeloid leukemia characterized by t(15;17) chromosomal translocation, which involves the retinoic acid receptor-alpha (RAR-alpha). APL typically presents with a life-threatening hemorrhagic diathesis. Before the introduction of all-trans retinoic acid (ATRA) for the cure of APL, fatal hemorrhages due, at least in part, to the APL-associated coagulopathy, were a major cause of induction remission failure. The laboratory abnormalities of blood coagulation found in these patients indicate the occurrence of a hypercoagulable state. Major determinants of the coagulopathy of APL are endogenous factors expressed by the leukemic cells, including procoagulant factors, fibrinolytic proteins, and non-specific proteolytic enzymes. In addition, these cells have an increased capacity to adhere to the vascular endothelium, and to secrete inflammatory cytokines [i.e. interleukin-1beta (IL-1beta) and tumor necrosis factor (TNF-alpha)], which in turn stimulate the expression of prothrombotic activities by endothelial cells and leukocytes. ATRA can interfere with each of the principal hemostatic properties of the leukemic cell, thus reducing the APL cell procoagulant potential, in parallel to the induction of cellular differentiation. This effect occurs in vivo, in the bone marrow of APL patients receiving ATRA, and is associated with the improvement of the bleeding symptoms. Therapy with arsenic trioxide (ATO) also beneficially affects coagulation in APL. However, early deaths from bleeding still remain a major problem in APL and further research is required in this field. In this review, we will summarize our current knowledge of the pathogenesis of the APL-associated coagulopathy and will overview the therapeutic approaches for the management of this complication.

The coagulopathy of acute promyelocytic leukaemia revisited

Since the initial description of the disease, the life-threatening coagulopathy associated with acute promyelocytic leukaemia (APL) has been the defining clinical characteristic. Historically, this uncommon subtype of acute myeloid leukaemia has been associated with a high mortality rate during induction therapy, most frequently attributable to haemorrhage. Since the introduction of all-trans retinoic acid (ATRA) into the therapy of all patients with APL, disease-free survival and overall survival have improved dramatically, such that the disease is now highly curable. However, induction mortality remains a major problem and haemorrhage still accounts for the majority of such early deaths. Pathogenesis of the coagulopathy is complex and includes disseminated intravascular coagulation (DIC), fibrinolysis and proteolysis. As a result, while the predominant clinical manifestation of the coagulopathy is haemorrhage, thromboembolic events may occur both at presentation and during therapy. A major recent finding is the high expression of annexin II in the leukaemic cells from patients with APL. Annexin II is a protein with high affinity for plasminogen and tissue-type plasminogen activator (tPA), and also acts as a cofactor for plasminogen activation by tPA. As a result, both plasminogen and tPA are increased on the cell surface of the leukaemic cell, increasing plasmin activity. Annexin II is expressed in high amounts in cerebral microvascular endothelial cells, perhaps accounting for the relatively high incidence of intracranial haemorrhage in APL compared with other sites. Microparticles are cell-derived membrane fragments originating from normal cells or released from malignant cells involved in activating coagulation. Recent studies have found that microparticles containing tissue factor, tPA, plasminogen activator inhibitor-1 and annexin II have been found in the plasma of APL patients, suggesting a role in pathogenesis of the coagulopathy. Treatment of the coagulopathy remains primarily supportive. Aggressive transfusions of platelets and cryoprecipitate appear to be important. There is no clear role for the routine use of heparin or antifibrinolytic therapy. The most important factor may be the early introduction of ATRA at the first suspicion of a diagnosis of APL, before it is confirmed genetically.

Bleeding and thrombosis in acute leukemia: what does the future of therapy look like?

Bleeding and thrombosis are major risk factors for early death in patients with acute leukemia; chemotherapy increases the likelihood of both of these complications. Patients with acute leukemia often present with a hypercoagulable state or with evidence for chronic disseminated intravascular coagulation, even in the absence of active thrombosis and/or bleeding. Leukemic cell procoagulant properties, cytotoxic therapies, and concomitant infections are major determinants of clotting activation in acute leukemia. Clinical manifestations range from localized venous or arterial thrombosis to diffuse life-threatening bleeding. All-trans retinoic acid has greatly improved the management of acute promyelocytic leukemia, but has not significantly changed the rate of early hemorrhagic deaths and may actually promote thrombosis. Randomized, controlled trials of different prophylactic regimens to prevent thrombosis and/or bleeding in acute leukemia are urgently needed, particularly in patients with acute promyelocytic leukemia. Anticoagulant therapy is a unique challenge in patients with acute leukemia, who are at high risk for hemorrhage. Although no guidelines are available for prophylaxis or treatment of thrombosis, extrapolation can be made from existing guidelines for management of patients with other malignancies prolonged periods of treatment-induced thrombocytopenia in patients with acute leukemia, however, require a more judicious application of standard anticoagulant approaches. Use of the newer anticoagulants will require careful assessment of hemorrhagic risk in this group of high risk patients but may be justified under special circumstances.

Cancer-associated thrombosis

There is strong evidence linking venous thromboembolic events and malignancy. Laboratory markers of coagulation activation such as thrombin-antithrombin complex or prothrombin fragments 1+2 support the premise that malignancy is a hypercoagulable state. Inflammatory cytokines (e.g. tumor necrosis factor and interferon-gamma), coagulation proteins (e.g. tissue factor and factor VIII), and procoagulant microparticles may be elevated in patients with malignancy. However, the molecular basis for cancer associated thrombosis remains unknown and the relative contribution of chemotherapeutics, tumor cells, endothelium, and circulating procoagulants in promoting thrombus formation continues to be investigated.

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.

[Physiopathological data of Horton's syndrome]

GREAT PROGRESS: The understanding of the physiopathology of Horton's syndrome has been made in view of the prevalence of the disease, the access to affected tissue and new molecular biology techniques. And it is now possible to specify the intricacy between the genetic, immunological and vascular components. HORTON'S SYNDROME, A GENETIC DISEASE: The preferential association of the disease with some alleles pf the HLA DR4 group has helped to emphasize the fundamental role of a few amino acids of the second hypervariable area of the HLA-DR molecule. An immunogenetic predisposition appears favourable, or even necessary, for the development of the disease. HORTON'S SYNDROME, AN IMMUNOLOGICAL DISEASE: The temporal arteries of patients presenting with Horton's syndrome are infiltrated by polymorphous inflammatory cells, fundamentally including CD4 T-cell lymphocytes, macrophages, and a few giant cells. Some CD4 lymphocytes have undergone clonal proliferation and show signs of recent antigenic recognition. A fraction of them secrete interferon gamma, which plays a crucial role in the onset, maintenance and orientation of the immunological response. The macrophages play multiple roles notably in maintaining the inflammatory reaction, but also in the destruction of certain structures of the arterial wall. HORTON'S SYNDROME, A VASCULAR DISEASE: The destruction of the arterial wall at the acute stage of the disease appears responsible, sometimes later on, for aneurismal dilatations observed on the aorta of certain patients. Moreover, intimal hyperplasia (mediated by the PDGF (platelet derived growth factor) A and B) and thrombosis (related to the inflammation) join up in reducing the arterial flow and enhancing the risk of ischemic complications during the acute stage. PATHOGENESIS, HYPOTHESES: Various candidate-antigens have been incriminated in the onset of the inflammatory reaction during Horton's syndrome. Some epidemiological and molecular studies are in favour of an exogenous antigen, possibly infectious, but no evidence has been demonstrated in the studies published. A parietal, endogenous antigen might also be at the origin of the cascade of events described during this disease.

Patogenia de la trombosis asociada a enfermedades neoplásicas: implicaciones terapéuticas

Malignancy is associated with a hypercoagulable state and a high risk for thrombohemorragic complications. Activation of blood coagulation in cancer is a complex phenomenon, involving many different pathways of the hemostatic system and numerous interactions of the tumour cell with other blood cells, including platelet, monocyte and endothelial cells. In addition, the involvement of fibrin formation in the processes of tumour spread and metastasis is important in this area. Experimental evidence suggest that TF expression in tumour cells is associated with enhanced procoagulant activity as well as increased tumour cell invasion, primary tumour growth and increased tumoral metastatic potential. Moreover, a close correlation exists between TF and the synthesis of the angiogenic cytokine VEGF in tumour cells and with angiogenesis in vivo. A number of agents designed specifically for targeting TF, VEGF and/or receptors are being evaluated in various clinical trials in cancer patients. This review discuss the current status in pharmacological interventions to block thrombogenicity and angiogenesis in the treatment of cancer.

Pathogenesis and management of the bleeding diathesis in acute promyelocytic leukaemia

Life-threatening bleeding, which remains a challenging complication of acute leukaemia, is particularly characteristic of the subtype, acute promyelocytic leukaemia (APL). The clinical picture and laboratory abnormalities are most compatible with the diagnosis of disseminated intravascular coagulation (DIC). Evidence for diffuse activation of the coagulation system, hyperfibrinolysis and systemic elaboration of non-specific protease activity can usually be demonstrated and occurs most commonly during induction chemotherapy. While both host- and tumour-associated mechanisms can be implicated in the pathogenesis of the coagulopathy, leukaemic cell properties appear to be the proximate cause of activation of the haemostatic mechanisms. In this chapter we summarize the current state of knowledge of the pathogenesis of the coagulopathy of APL and the therapeutic approaches that have proved most useful for the management of this complication. Special attention is devoted to the use of all-trans-retinoic acid (ATRA), which has revolutionized the treatment of APL and markedly ameliorated the APL-related coagulopathy.

Defibrotide reduces procoagulant activity and increases fibrinolytic properties of endothelial cells

Defibrotide (DF), a polydeoxyribonucleotide with antithrombotic properties, has recently proven effective in patients with severe hepatic veno-occlusive disease (VOD), a life-threatening complication of high-dose chemo/radiotherapy regimens for stem cell transplantation. To understand the mechanism of its beneficial effect, we studied the impact of DF on the expression of tissue factor (TF) and fibrinolytic proteins (PAI-1 and t-PA) on endothelial cells. The in vitro response to DF of two types of human endothelial cells (ECs) of different origins, that is from macrovascular (HUVEC) and microvascular (HMEC-1 cell line) beds, was evaluated in the presence or absence of a proinflammatory stimulus (ie bacterial endotoxin, LPS). The results show that DF was able to significantly reduce the LPS-induced TF expression by HMEC-1, and less prominently by HUVEC. In addition, DF importantly influenced the fibrinolytic properties of both HMEC-1 and HUVEC. Specifically, it dose-dependently counteracted the LPS-induced increase in PAI-1 levels and decrease in t-PA activity expression. It also significantly incremented t-PA antigen in resting EC. Decreasing the procoagulant activity and increasing the fibrinolytic potential of EC favors an anticoagulant phenotype of the endothelium, which may protect from fibrin deposition and vascular occlusion.

Pathophysiology of disseminated intravascular coagulation (DIC) progresses at a different rate in tissue factor-induced and lipopolysaccharide-induced DIC models in rats

Tissue factor (TF) and lipopolysaccharide (LPS) are frequently used to induce disseminated intravascular coagulation (DIC) in experimental animal models. Although the pathophysiology of DIC may differ depending on which agent is used for induction, previous studies on models of DIC have not distinguished which DIC-inducing agent was used. In the present paper, we evaluate the characteristics of TF-induced and LPS-induced DIC using two types of DIC models, with special reference to selected hemostatic parameters and pathological findings within the kidney. Male Wistar rats were administered TF (3.75 U/kg; sustained infusion for 4 h) or LPS (30 mg/kg; sustained infusion for 4 h) via the tail vein, and blood sampling was performed at 0, 1, 3, 4, 5, 7, 9, 11, and 28 h. Judging from changes in the levels of thrombin-antithrombin complex, fibrinogen levels, and platelet counts, it is reasonable to conclude that the severity of both types of experimental DIC is similar with regard to hemostatic activation and consumption coagulopathy. A marked elevation in the level of D-dimer was noted without any organ dysfunction or much fibrin deposition in the kidney upon administration of TF. However, a markedly prolonged period of elevation in plasminogen activator inhibitor activity, a prolonged depression in antithrombin III activity, severe organ failure, and a markedly prolonged period of fibrin deposition in the kidney was observed following LPS administration. A modest number of the rats from the TF-induced DIC model died during the experimental period, whereas a large number of rats died during LPS-induced DIC, especially after 9 h. Since the time course of the pathophysiology differed remarkably among the TF-induced and LPS-induced DIC models in rats, we recommend that TF-induced and LPS-induced DIC be approached as distinct models in order to determine the implications of their experimental and clinical use.

Marked difference in pathophysiology between tissue factor- and lipopolysaccharide-induced disseminated intravascular coagulation models in rats

OBJECTIVE

Tissue factor and lipopolysaccharide frequently have been used to induce disseminated intravascular coagulation in experimental animal models. Although the pathophysiology of disseminated intravascular coagulation may differ according to the agents used to induce it, these previous models have not distinguished between the use of different disseminated intravascular coagulation-inducing agents. In this study, we attempted to evaluate the characteristic features of these agents in two types of disseminated intravascular coagulation models, with special reference to selected hemostatic parameters and pathologic findings in the kidney.

DESIGN

Prospective, comparative, experimental study.

SETTING

Laboratory at a university hospital.

SUBJECTS

Twenty-seven male Wistar rats, age 6-7 wks, weighing 160-170 g.

INTERVENTIONS

Three groups of animals were studied: a control group (n = 8) receiving physiologic saline, a tissue factor-treated group (n = 11) receiving tissue factor 3.75 units/kg, and a lipopolysaccharide-treated group (n = 8) receiving lipopolysaccharide 30 mg/kg; each group sustained infusion for 4 hrs via the tail vein.

MEASUREMENTS AND MAIN RESULTS

The degree of hemostatic activation in both types of experimental disseminated intravascular coagulation was identical, based on the results of thrombin-antithrombin III complex levels. Markedly elevated D-dimer concentrations were observed without organ dysfunction or fibrin deposition in the kidney on administration of tissue factor, whereas markedly elevated plasminogen activator inhibitor activity, decreased antithrombin III activity, severe organ failure, and marked fibrin deposition in the kidney were observed for lipopolysaccharide administration.

CONCLUSION

Because pathophysiology differed remarkably between the tissue factor- and lipopolysaccharide-induced disseminated intravascular coagulation models in rats, we recommend that they be assessed carefully as distinct entities to determine implications of their experimental and clinical use.

Molecular basis for the relationship between thrombosis and cancer

Cancer patients are highly susceptible to thromboembolic complications, which some have estimated accounts for a significant percentage of the morbidity and mortality of the disease. Not all of the mechanisms for the production of the hypercoagulable state characteristic of cancer are entirely understood. Those that are known seem to interdigitate the biology of cancer with the major regulatory pathways that mediate blood coagulation, platelet-vessel wall interaction, fibrinolysis and inflammatory cytokine production. In other words, the events responsible for thrombosis in cancer appears to be a result of an over exuberant host response in an attempt to delimit tumor growth. In this brief review, therefore, we attempt to put into the context of tumor growth, angiogenesis and metastasis the current information about the pathogenesis of venous thromboembolism (VTE).

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.

Subclinical alterations in coagulation and fibrinolysis in patients undergoing autologous peripheral blood stem cell transplantation

We monitored 30 laboratory hemostatic parameters in an attempt to better comprehend alterations in coagulation and fibrinolysis in 10 patients with hematological malignancies subjected to autologous peripheral blood stem cell transplantation (APBSCT). These parameters were assessed before and just after high-dose conditioning chemotherapy, on days 1, 7, 14 and 28. Although, clinical manifestations associated with fibrino-coagulation disorders never occurred, including veno-occlusive disease, a statistically significant increase was seen in 7 of 30 parameters, compared to values seen before conditioning chemotherapy. These were subdivided into early and late phase parameters. The early phase parameters, which increased during the first day after the conditioning chemotherapy was given, then returned to baseline values, included protein C, plasma tissue factor and tissue-plasminogen activator. The late phase parameters, which increased over baseline values during days 7 to 28, included free-protein S, fibrinogen, plasmin-alpha2-plasmin inhibitor complex and soluble-thrombomodulin. The increase of early phase parameters, as produced by the liver and by endothelial cells, may reflect tissue damage by conditioning chemotherapy. Late phase parameters increased in parallel with C-reactive protein, which suggests a correlation with the degree of inflammation, such as the presence of infective disease during neutropenia. These subclinical alterations in coagulation and fibrinolysis which take on a biphasic pattern during the course of APBSCT should be kept in mind by the attending physicians during therapy.

Oncologic emergencies

The prognosis for the child with cancer has improved dramatically over the past decades. With this success comes the need for recognition and proper treatment of emergencies. Respiratory or circulatory failure may arise from compression of the SVC or airway. Epidural spinal cord compression by tumor may lead to irreversible paraplegia or urinary incontinence if intervention is not rapid. Raised intracranial pressure may be a life-threatening presentation of a brain tumor. Bone marrow failure, with anemia and thrombocytopenia, is associated with malignant infiltration of the marrow. Hyperleukocytosis carries a high risk of thrombotic events if not treated promptly. Coagulation abnormalities are seen in many childhood cancers at the time of diagnosis. Life-threatening metabolic abnormalities are observed at presentation in children with leukemia and lymphoma. Hypercalcemia, although rare, may be a difficult situation to correct. Immediate attention to these emergencies and appropriate treatment may save the life of a child with cancer or make his or her subsequent course just a little smoother.

Acute promyelocytic leukaemia in the all trans retinoic acid era

Bleeding diathesis is a common complication of acute promyelocyctic leukaemia (APL). Multiple haemostatic defects are found in most patients with APL, which often worsen following cytoreductive chemotherapy. Besides thrombocytopenia, most patients develop disseminated intravascular coagulation, systemic fibrinolysis or both. A major aim in treating haemostatic defects of APL is to prevent death or disability from bleeding until chemotherapy clears the malignant promyelocytes from the blood and bone marrow. The therapeutic options are discussed in this review and practical guidelines for treatment are outlined.

[Venous thrombosis on central catheters in oncology]

Central venous catheters have considerably improved the comfort and safety of chemotherapy in cancer patients. However complications as thrombosis could occur and their incidence vary from 3.7 to 42% in oncology. Catheter placement induces modifications of vascular system with formation of a fibrin sleeve and/or a mural thrombus. Thrombosis origin is linked with catheter itself, its position and the biomaterial used. Hypercoagulable state in cancer results from the perturbation of blood flow, the composition of blood itself and the vessel wall, and increases the iatrogenic effects of indwelling catheters. Finally chemotherapy used in the treatment of cancer has been associated with an increased incidence of thromboembolic events, suggesting the proposal of an antithrombotic prophylaxis in cancer patients receiving chemotherapeutic agents through indwelling catheter.

Modulation of human endothelial cell procoagulant activity in tumour models in vitro

Several tumour-derived factors have recently been identified which induce tissue factor (TF) expression in endothelial cells in vitro. However, there is only limited evidence that endothelial cells lining tumour blood vessels express elevated procoagulant activity (PCA) in vivo. We have investigated the effects of human breast and small cell lung cancer cell lines on the PCA of human micro- and macrovessel endothelial cell monolayers using a one-stage clotting assay, as well as detection of TF mRNA by RT-PCR. Only conditioned medium from the MDA-MB-231 breast adenocarcinoma cell line produced a consistent although transient increase in endothelial cell surface PCA, which was maximal by 6-9 hr. TF mRNA was detectable in the endothelial cells after 1 hr incubation with MDA-MB-231-conditioned medium and subsequently fell below detectable levels. Following 24 hr stimulation, nearly half the endothelial cell PCA was due to the presence of TF-containing membrane vesicles shed by the MDA-MB-231 cells. Consistent with these findings, the MDA-MB-231 cell line expressed high levels of cell surface-associated TF activity. Co-culture of MDA-MB-231 and endothelial cells for up to 5 days increased (approx. 118-fold) PCA associated with endothelial cell monolayers, due mainly to sequestration of shed tumour cell vesicles. Our results suggest that induction of TF de novo is not a common feature in the supporting endothelium of these tumour types.

A prothrombotic state in breast cancer patients treated with adjuvant chemotherapy

Cancer is often associated with abnormal activation of coagulation leading to a prothrombotic state. Some chemotherapeutic agents used for cancer may induce thrombosis but their biological alterations in the hemostatic system are not yet well understood. This study evaluated alterations of coagulative and fibrinolytic parameters following chemotherapy. In plasma samples of 38 patients (median age: 49 years) receiving CMF (schedule 1-21 or 1-8) for Stage II breast cancer, we evaluated: PT, aPTT, antithrombin III (AT-III), protein C (PC), protein S (PS), thrombin-antithrombin complex (TAT), prothrombin fragment F 1 + 2 (F 1 + 2), fibrinogen (Fbg), tissue-type plasminogen activator (t-PA), plasminogen activator inhibitor (PAI-1) and D-dimer (D-D). PT, aPTT, and Fbg were determined with routine methods; AT-III, PC, and PS were measured with coagulative tests; PC and PS were also evaluated with immunoenzymatic methods, t-PA, PAI-1, D-D, TAT, and F 1 + 2 were measured with immunoenzymatic methods. All tests were performed immediately before starting therapy and after each cycle. A PC antigen decrease appeared soon after beginning therapy and lasted throughout chemotherapy. The lowest values were present after the first treatment both in the CMF 1-21 group (mean +/- SD = 72.5 +/- 10.8%) and in the CMF 1-8 group (mean +/- SD = 77.2 +/- 6.9%): PC activity was also decreased. PS antigen decreased after the first administration (mean +/- SD = 73.3 +/- 10% in CMF 1-21 group, and 72.5 +/- 4.9% in CMF 1-8 group): PS activity also decreased. PAI-1 antigen levels increased (mean +/- SD = 43.1 +/- 20.4 ng/ml in the CMF 1-21 group, and 37.5 +/- 12.2 ng/ml in CMF 1-8 group) lasting up to the last cycle. CMF provokes a trend toward hypercoagulability; this effect should be considered when chemotherapy is employed in advanced cancer patients at high risk for thrombosis, or in patients with other risk factors.

Coagulation disorders in cancer

Coagulation disorders are common in cancer patients. This article reviews the coagulation laboratory findings in these patients and the thromboembolic and hemorrhagic manifestations of malignancy. Among the many topics addressed are Trousseau's syndrome, disseminated intravascular coagulation, and acquired von Willebrand disease. Pathogenesis of the coagulation disorders and recommendations for treatment of various syndromes are discussed.

Tissue factor expression in human leukemic cells

Patients with acute leukemia are at increased risk for thrombotic and hemorrhagic complications, particularly those patients with acute promyelocytic leukemia (APL) undergoing induction chemotherapy. These serious complications have been attributed by some authors to the release of tissue factor (TF) procoagulant activity (PCA), particularly during cytotoxic chemotherapy. In previous studies of normal peripheral blood cells, only cells of the monocyte lineage have been found to express TF PCA. Therefore, several questions remain regarding the origin and characterization of the PCA in malignant leukemic cells, particularly those thought to be derived from granulocyte progenitor cells. We utilized a full-length cDNA probe, several monoclonal antibodies (MAbs) and a sensitive one-stage PCA assay to study the expression of TF in the human cell line, HL-60, in human peripheral blood monocytes/macrophages (Mo/Mø) and in highly purified populations of human polymorphonuclear leukocytes (PMN). In the HL-60 cells we detected low but significant levels of TF mRNA and TF antigen (TF:Ag). In unstimulated cells, coordinate increased levels of TF mRNA, TF:Ag and TF PCA expression were noted following phorbol-ester-induced macrophage differentiation of the cells, but a decreased level of TF mRNA with no change in the basal level of TF:Ag expression occurred following retinoic acid-induced granulocyte differentiation of this cell line. Long-term cultures of stimulated mature Mo/Mø demonstrated initial coordinate expression of TF mRNA, TF:Ag and TF PCA, but TF:Ag expression persisted even after 7 days (when TF PCA was undetectable). No TF PCA, TF:Ag or TF mRNA was demonstrated in highly purified populations of human PMN, regardless of culture conditions. Discordant expression of TF mRNA, TF:Ag and TF PCA in HL-60 cells suggests the possibility of novel, post-synthetic mechanisms for the regulation of TF PCA expression, which might be dependent on the phenotypic differentiation level of the cell. Such mechanisms (yet to be defined) might account for the ability of some leukemic cells, which frequently express characteristics of more than one cell line (e.g. monocytes and granulocytes), to express a TF gene product capable of activating blood coagulation.

Disseminated intravascular coagulation in acute leukaemias at first diagnosis

Haemorrhagic diathesis is the commonest cause of morbidity and mortality in acute leukaemias (AL). It is most commonly due to thrombocytopenia resulting from bone marrow failure. However, in a significant number of cases, disseminated intravascular coagulation (DIC) plays an important part. Previously it was thought that this mechanism was mainly confined to acute promyelocytic leukaemia (APL), but recently it has also been reported to occur in other subtypes of acute leukaemia. We report the results of a study carried out to find the incidence of DIC in various types of AL at the time of first diagnosis and in the absence of other recognisable causes. DIC was observed in 14(13.4%) cases out of 104 cases of AL studied. Nine out of 49(18.4%) cases of AML and 5 out of 55(9.1%) cases of acute lymphoblastic leukaemia (ALL) showed coagulation abnormalities consistent with DIC. Out of the 9 cases of AML showing DIC, 63 (66.67%) belonged to APL (FAB ME) subtype. Three (60%) out of 5 cases of ALL with DIC had T-cell immunophenotype. The results indicate that DIC may also occur in types of AL other than APL, particularly in T-ALL, and should be looked for.

Recurrent venous thrombosis as the presenting manifestation of acute lymphocytic leukemia: leukemic cell procoagulant activity is not responsible for the hypercoagulable state

The association of cancer with clinical abnormalities of blood coagulation, including superficial thrombophlebitis, deep vein thrombosis (DVT), and disseminated intravascular coagulation (DIC) is well-known, particularly in patients with solid tumors and acute promyelocytic leukemia (APL). Less commonly appreciated is the potential for the development of venous thromboembolic disease (TED) in patients with acute lymphocytic leukemia (ALL). Multiple mechanisms have been implicated for the activation of coagulation in these patients, with an emphasis on the contribution made by the procoagulant properties of the tumor cells themselves. We present two cases of patients with pre-B cell ALL, both of whom developed recurrent TED as the presenting manifestation of their leukemia and/or heralding relapse. The blast cells from one of the patients were studied for the presence of procoagulant activity (PCA) and by Northern blot analysis for tissue factor (TF) messenger RNA (mRNA). Neither PCA nor TF mRNA could be identified in highly purified populations of the lymphoblast cells. We conclude that recurrent TED can be a manifestation of ALL and that mechanisms other than the release of tumor cell procoagulants should be sought to explain the pathogenesis of thrombosis in some patients.

Correlation between increased granulocyte elastase release and activation of blood coagulation in patients with lung cancer

BACKGROUND

Coagulopathies often are associated with malignant tumors. The pathogenesis of these complications in cancer is not clear. Host inflammatory (monocyte/macrophage) cell-mediated triggering of clotting activation has been suggested.

METHODS

The objective of this study was to evaluate the role of neutrophil-derived elastase in the activation of blood coagulation and fibrinolysis in lung cancer. The study population was 42 consecutive patients with lung cancer (34 men and 8 women). Thirteen patients had small cell lung cancer (SCLC), 13 had squamous cell lung cancer, and 16 had adenocarcinoma. Hemostatic function was assessed by measuring D-dimer (DD), thrombin-antithrombin III complex (TAT), plasmin-alpha 2-antiplasmin complex (PAP), fibrin degradation product (FDP), fibrinogen, prothrombin time (PT) and activated partial thromboplastin time (APTT). Elastase-alpha 1-protease inhibitor (EPI) complex was measured as a marker of neutrophil activation.

RESULTS

Significant elevation of the elastase plasma levels and coagulation-fibrinolysis parameters was found in patients with cancer compared with control subjects. Among all patients, the plasma concentration of EPI was significantly correlated with APTT, DD, TAT, PAP, and fibrinogen. Although in patients with non-small cell lung cancer (non-SCLC), DD, TAT, PAP, APTT, and fibrinogen were significantly correlated with EPI, such a correlation was not found in patients with SCLC. Patients with non-SCLC had stronger correlation of EPI with TAT, PAP, and PT than did patients with advanced stages of disease.

CONCLUSION

The activation of coagulation-fibrinolysis system in lung cancer may be triggered, at least in part, by an increased release of neutrophil elastase. This mechanism is stage related and seems to operate predominantly in non-SCLC.

New insights into the pathogenesis of coagulation dysfunction in acute promyelocytic leukemia

Patients with acute promyelocytic leukemia (APL) are at high risk for the development of life-threatening thrombotic and hemorrhagic complications, particularly during induction chemotherapy. This propensity has been attributed to the release of tissue factor (TF)-like procoagulants from the leukemic cells leading to disseminated intravascular coagulation (DIC). However, recent data suggest that the pathogenesis of the coagulopathy is more complicated and may involve activation of the generalized proteolytic cascade resulting in either clotting and/or excessive fibrinolysis. Furthermore, controversy exists regarding the mechanism(s) responsible for the activation of either clotting or fibrinolysis. The malignant promyelocyte may act directly to activate coagulation and/or fibrinolysis. Alternatively, reactive inflammatory cells, which express procoagulant and/or profibrinolytic activities may play an essential role. A third possibility may involve endothelial cell expression of mediators with procoagulant/profibrinolytic properties. Putative profibrinolytic mechanisms include the release of urokinase-type and tissue-type plasminogen activators, decreases in plasminogen activator inhibitor-1 and 2, and decreases in alpha-2 plasmin inhibitor. Putative procoagulant mechanisms include the release of tissue factor, Cancer Procoagulant, or cytokines such as interleukin-1, tumor necrosis factor and vascular permeability factor. Putative anticoagulant mediators include annexins, a group of proteins in human tissue which bind phospholipids and have anticoagulant activity, which have been reported in patients with APL. The current treatment of APL is rapidly evolving because of the efficacy of all-trans retinoic acid (ATRA). All-trans retinoic acid promotes terminal differentiation of leukemic promyelocytes leading to complete remission in the majority of patients with APL with rapid resolution of the coagulopathy. Although the mechanism by which this occurs has not been established, preliminary data suggest that ATRA blocks the downregulation of the thrombomodulin gene and the up-regulation of the tissue factor gene induced by tumor necrosis factor. Since APL is a relatively uncommon disorder, the collaboration of cooperative oncology groups will be important to study patients receiving ATRA or conventional chemotherapy to further elucidate the mechanism(s) of the coagulopathy.

Tissue factor as a tumor procoagulant

Tissue factor is a cell surface glycoprotein responsible for initiating the extrinsic pathway of coagulation. Many tumor cell homogenates and intact tumor cells have been shown to contain tissue factor activity. Immunohistochemical studies show that many tumors associated with Trousseau's syndrome express tissue factor on their cell surfaces. Tumor cells shed membrane fragments which carry tissue factor that can account for the activation of the clotting system. Tumor cells also produce soluble substances that can induce tissue factor expression on host cells, such as endothelium and monocytes, at sites distant from the tumor. Although, all the functional TF molecules are localized on the outer cell membrane in many tumor cells, the procoagulant activity on the intact cell surface is largely dormant and can be greatly enhanced upon cell injury or damage. Tissue factor procoagulant activity on the cell surface can be modulated by alterations in the plasma membrane without loss of cell viability. Tissue factor activity on cell surfaces is largely regulated by a plasma inhibitor, tissue factor pathway inhibitor. This inhibitor binds to both functional and non-functional tissue factor/VIIa complexes on the cell surface and prevents non-functional tissue factor/VIIa complexes from becoming functional after cell injury or lysis. Heparin, but not warfarin, therapy is effective in preventing the occurrence of devastating thrombotic events in patients with Trousseau's syndrome and the reason(s) for this are still unknown.

Hemostatic alterations in cancer patients

Nearly all patients with cancer manifest laboratory evidence of hypercoagulability and some develop clinical thromboembolic disease (TED). Routine laboratory studies of blood coagulation have been performed in several large, prospective trials of the use of anticoagulant drugs in cancer treatment. The results of these studies, as well as data from several smaller studies of more sensitive tests of hypercoagulability [e.g. fibrinopeptide A (FPA); thrombin-antithrombin (TAT) complexes; prothrombin fragment F1 + 2)], indicate that the levels of some clotting proteins parallel disease activity. However, no studies of sound methodologic design have yet been performed to indicate that any of these tests of blood coagulation can serve as adequate predictors of TED in patients with cancer. In addition to the important role played by tumor-related procoagulants, several other mechanisms may be involved in the pathogenesis of thromboembolic events in patients with cancer, including stasis and endothelial damage. Considerable variability in the relative importance of these mechanisms in the pathogenesis of TED may exist among patients with different types of cancer. The risk for TED associated with surgical procedures in cancer patients is substantial and prophylactic antithrombotic therapy should be considered for most of these patients. Chemotherapy and hormonal therapy of cancer probably increases the likelihood of TED, particularly in those subjects with indwelling venous catheters. This risk has been particularly well-studied in patients with breast cancer treated with tamoxifen plus cytotoxic drugs. The pathogenic mechanisms may be complex but vascular injury is likely as a proximate cause of venous access catheter thrombosis and can be prevented with low dose coumadin therapy. The utility of low dose coumadin anticoagulation in reducing the risk for TED during breast cancer treatment is unknown but is currently being tested in a large, multiinstitutional study. Since chronic coumadin anticoagulation of cancer patients, and single pulse dose heparin prior to intravenous chemotherapy, both prevent thrombin generation, these agents may be of use in reducing the risk of chemotherapy-associated thrombosis. Prophylactic anticoagulation should be considered for high risk patients.

Protein C activity, stage of disease, and vascular thrombosis in colon carcinoma

To determine the etiology of the increased incidence of postoperative deep venous thrombosis (DVT) in patients with carcinoma of the colon, serum levels of protein C were measured preoperatively in 65 patients with colorectal adenocarcinoma. Noninvasive lower-extremity Doppler studies were performed on all patients prior to discharge to assess patency of the deep veins. Six patients (9%) were found to have DVT. The protein C level was considered elevated if it was greater than 125% of control values and reduced if less than 75% of control values. The development of DVT was found to be independent of the serum carcinoembryonic antigen, albumin, total protein, hemoglobin, hematocrit, platelet count, prothrombin time, partial thromboplastin time, and the patient's age and percentage of ideal body weight. There was an inverse relationship between the protein C level (p less than 0.001), Dukes stage of the tumor (p less than 0.001), and the development of DVT. Linear regression analysis revealed that only the tumor stage and the protein C level could be used to predict the development of DVT. The data show that for these patients with colorectal malignancy, the development of DVT may be related to decreased levels of protein C.

Disseminated Intravascular Coagulation: Pathogenesis and Management

Disseminated intravascular coagulation (DIC) is a clini-copathological syndrome secondary to an underlying disease. Characteristic laboratory abnormalities of DIC should suggest, much like the recognition of fever, anemia, or congestive heart failure, that an inciting disease process must be searched for. The clinical and laboratory consequences of DIC can be ascribed to the unregulated and unbalanced formation of thrombin, the main clot-forming enzyme, and plasmin, the main clot-lysing enzyme. If too much plasmin is formed in relation to thrombin, a hemorrhagic state, which appears in 60 to 75% of patients with deep vein thrombosis, will occur. Alternatively, if too much thrombin is formed in relation to the degree of secondary fibrinolysis, a thrombotic condition, which appears in 25 to 40% of patients with DIC, will become manifest. The diagnosis of DIC is dependent on the presence of an appropriate clinical situation with concurrent laboratory evidence of thrombin and plasmin formation. Thrombin formation, plasmin formation, or both, can be assessed by detection of fibrin monomer, fibrin/fibrinogen degradation products, and D-dimer or E fragment, respectively. Treatment of DIC should initially be addressed to treatment of the primary, underlying condition inciting the disorder. If treatment for DIC is specifically needed, blood product replacement is the first order of therapy. This replacement should be tailored to each patient's specific needs (i.e., platelets, fibrinogen, or plasma proteins). Heparin has a definite but limited use in conditions associated with acral cyanosis and dermal ischemia. Other specific therapies for DIC may be of use in individualized situations.

Coexisting macrophage-associated fibrin formation and tumor cell urokinase in squamous cell and adenocarcinoma of the lung tissues

Mechanisms of coagulation activation in situ were studied by means of immunohistochemical techniques applied to surgically resected primary adenocarcinomas and squamous cell carcinomas of the lung. Findings in these two histologic types were similar. Double-labeling techniques using macrophage-specific antibody together with antibody to either tissue factor, factor VII, factor X, or factor V revealed coincident staining for each of these coagulation factors on tumor-associated macrophages. Staining of tumor cells for these factors was rare and inconsistent. Both macrophages and fibroblasts in the tumor connective tissue stained for the a subunit of factor XIII. Fibrinogen was abundant throughout the tumor connective tissue, but staining for fibrin and D-dimer cross-linked sites of fibrin was restricted to areas adjacent to macrophages, indicating that thrombin was generated in association with tumor macrophages but not with tumor cells. By contrast, tumor cells stained diffusely for urokinase-type plasminogen activator and focally for thrombomodulin. These findings contrast with those reported previously for small cell carcinoma of the lung and suggest that coagulation activation in adenocarcinoma and squamous cell carcinoma of the lung may occur indirectly through activation of certain host cells such as macrophages. By contrast, tumor cell plasminogen activator may mediate certain aspects of the malignant phenotype in these tumor types.

Fibrin formation on vessel walls in hyperplastic and malignant prostate tissue

To explore mechanisms of coagulation activation in adenocarcinoma of the prostate, the occurrence and distribution of components of coagulation and fibrinolysis pathways in situ were studied by means of immunohistochemical techniques applied to frozen sections of fresh malignant and benign hyperplastic prostatic tissue obtained at transurethral resection. Fibrinogen was distributed throughout the perivascular and tumor connective tissue in both malignant and benign disease but was not present in adjacent areas of normal prostate. Antibodies specific for fibrin and D-dimer crosslink sites stained vascular endothelium focally in both malignant and benign tissues. Both neoplastic cells and benign hyperplastic glandular epithelial cells stained weakly and in a patchy distribution for tissue factor and focally for low-molecular-weight urokinase-type plasminogen activator. Focal staining of vascular endothelium was also observed for tissue plasminogen activator and plasmin-antiplasmin complex neoantigen. By contrast, no tissue staining was observed for factor VII, factor X, factor XIII "a" subunit, high-molecular-weight urokinase-type plasminogen activator, plasminogen activator inhibitors 1 to 3, protein C, and protein S. Thus, the similarity in findings between benign hyperplastic and neoplastic prostate tissue, the lack of either an intact tumor cell-associated coagulation pathway or fibrin formation, and the presence of fibrin on vascular endothelium are consistent with the concept that coagulation activation in prostatic cancer may not be due to a direct effect of the tumor cells on the clotting mechanism. Rather, such activation may be induced by a soluble tumor product that activates procoagulant activity on certain host (for example, vascular endothelial) cells. These findings, together with the lack of effect of warfarin anticoagulation on the clinical course of patients with prostatic cancer, contrast with findings in certain other tumor types and suggest that coagulation activation may not contribute to progression of adenocarcinoma of the prostate.

Plasma thrombin-antithrombin III complexes in the diagnosis of primary hepatocellular carcinoma complicating liver cirrhosis

Detection of hypercoagulable state might be helpful in the diagnosis of primary hepatocellular carcinoma (HCC) complicating liver cirrhosis (LC). Plasma levels of thrombin-antithrombin III complex (TAT) were determined in 50 patients of LC with or without HCC. The levels were above 2 ng/ml in 80% of 25 HCC patients, but only in 12% of 25 non-HCC patients (P less than 0.01). The levels over 2 ng/ml occurred even in five of six HCC patients whose serum alpha-fetoprotein levels were below 20 ng/ml as well as in two of three patients with HCC less than 2 cm in diameter. Those levels in HCC patients were significantly decreased within 8 days after treatment with transcatheter arterial embolization or infusion of antitumor agents, without affecting plasma antithrombin III levels. These results suggest that plasma TAT levels may be useful in the diagnosis of HCC complicating LC.

Interleukin 1 production by monocytic leukemia cells and its possible role in coagulation abnormalities

Interleukin 1 (IL-1) production by leukemic cells was studied in 16 patients with myelocytic or monocytic leukemia. Leukemic cells from the patients with monocytic leukemia showed higher IL-1 production than those with myelocytic leukemia. Subclinical coagulation abnormalities were observed more frequently in patients with higher IL-1 producing monocytic leukemia. It is suggested that IL-1 from leukemic cells might play important roles in the establishment of these clinical features. Such observations might be of value in the understanding of the pathophysiology of leukemia-associated paraneoplastic phenomena.

Interleukin-1 and interleukin-2 control granulocyte- and granulocyte-macrophage colony-stimulating factor gene expression and cell proliferation in cultured acute myeloblastic leukemia

In vitro proliferation of leukemic cells purified from 10 cases of acute myeloblastic leukemia (AML) was analyzed in basal conditions or in the presence of exogenous recombinant (r) Interleukin (IL) 1. In parallel, blasts from 5 of these patients were studied for granulocyte-macrophage colony-stimulating factor (GM-CSF) or granulocyte-CSF (G-CSF) mRNA. IL-1 augmented the spontaneous AML cell proliferation in all cases and induced de novo expression or increased amounts of GM-CSF and/or G-CSF transcripts in 4 of the 5 cases evaluated. IL-1-induced AML cell proliferation was modulated by neutralizing anti-GM-CSF or anti-G-CSF antibodies in those cases in which CSF mRNAs were induced or increased by exogenous cytokine. In the same cases, biosynthetic labelling and immunoprecipitation studies using monospecific anti-GM-CSF antibodies showed that IL-1 also increased the levels of GM-CSF protein synthesis. Addition of neutralizing anti-IL-1 antibodies to AML cell cultures completely abolished ongoing GM-CSF synthesis, suggesting that endogenous IL-1 is needed to maintain autocrine production of CSFs. The effects of rIL-2 were investigated in a larger series of 21 patients. The cytokine reduced spontaneous AML cell proliferation in 8 cases. It caused complete disappearance of GM-CSF mRNA in 1 case, and marked reduction of G-CSF mRNA in 2 cases. Increased AML cell proliferation was observed in 2 of 21 cases. These findings suggest that expression of CSF genes and cell proliferation in AML are under the control of different cytokines acting in autocrine or paracrine fashion.

Interleukin-1: biology, pathophysiology, and clinical prospects

Interleukin-1 (IL-1) is a cytokine with multiple biologic activities. Since its first description in 1972, significant work has been done, leading to an understanding of the biology of IL-1, which plays a central role in many important functions of the immune system. The biologic activities of IL-1 make it an attractive factor for use in clinical oncology, both as an antitumor agent and for the hematologic recovery of cancer patients receiving other forms of therapy. In this review the biologic effects of IL-1 are summarized. The possible involvement of IL-1 in the pathogenesis of some diseases is reviewed. Future prospects for the use of IL-1 in the treatment of malignancies are discussed.

The coagulopathy of childhood leukemia. Thrombin activation or primary fibrinolysis?

Little information is available on the prevalence and etiology of the coagulopathy present in some children with acute leukemia at disease presentation. We studied 102 children with newly diagnosed acute leukemia (50 retrospective: Group A; and 52 prospective: Group B) with prothrombin time (PT), partial thromboplastin time (PTT), thrombin time (TT), fibrinogen (FIB), and fibrin degradation products (FDP). All patients in Group B also had assessment of thrombin activation by measurement of the crosslinked fibrin fragment, D-dimer, and of primary fibrinolysis with the B beta 1-42 peptide. Additionally, ten patients from Group B had Factors II, V, VII, and X measured, and eight of these patients had measurement of tissue factor from sonicated bone marrow cells. Thirty-two percent of Group A and 40% of Group B had totally normal coagulation studies, whereas 20% of Group A and 10% of Group B had a severe coagulopathy on disease presentation. A high percentage of both groups had elevated PT (Group A, 52%; Group B, 27%) and increased FDP (Group A, 39%; Group B, 25%). In Group B, 38% of the patients had a positive D-dimer, whereas only 4% of this prospective group had an elevated B beta 1-42 peptide (P less than 0.00001). Nine of ten patients with a positive D-dimer had low levels of one or more of the extrinsic pathway factors. Three of four patients with the highest tissue factor levels were of monocytoid leukemia cell type. These data indicate that the coagulopathy associated with acute leukemia of childhood is usually mediated by thrombin activation.