Acquired activated protein C resistance is common in cancer patients and is associated with venous thromboembolism

Comprehensive evaluation of genetic and acquired thrombophilia markers for an individualized prediction of clinical thrombosis in patients with lymphoma and multiple myeloma

Patients diagnosed with lymphoma or multiple myeloma are at elevated risk of venous thromboembolism (VTE). Optimum risk stratification and effective thromboprophylaxis can only be achieved through the development of a multiple-specific risk score that successfully captures all aspects of the heterogeneous prothrombotic environment existing in these patients. Our aim was to identify risk factors for thrombosis and suggest an improved tool combining clinical data, thrombo-inflammatory biomarkers and genetic (Thrombo inCode® test) variables for predicting thrombotic risk in patients with lymphoma and multiple myeloma. A prospective longitudinal study was conducted on newly-diagnosed lymphoma and multiple myeloma patients who presented at our institution between February 2020 and January 2021. The study included 47 patients with lymphoma and 16 patients with multiple myeloma. We performed a follow-up of 1 year or until September 2021. The incidence of venous thrombosis and associated risk factors were analysed, including the genetic Thrombo inCode® test. Khorana and ThroLy scores for lymphoma patients and IMPEDE VTE score for myeloma patients were calculated. At a median follow-up of 9.1 months, VTE incidence was 9.5% (6/63), with 4 and 2 patients with lymphoma and myeloma who developed the events, respectively. Univariate analysis showed that the incidence of thrombosis was significantly higher in patients with ECOG ≥ 2 and prior immobility. Median factor VIII levels were significantly higher in patients with thrombosis (with increased values in all of them). Moreover, there was a trend in genetic variant rs5985 (factor XIII) as a protective factor, and a trend to higher thrombotic risk in patients with factor V Leiden, rs2232698 variant (serpinA10), low total protein S activity, elevated D-dimer, aggressive lymphoma and treatment with dexamethasone. The results of our study demonstrate promise for the potential use of widely accessible markers to increase precision in risk prediction for VTE in patients with lymphoma and multiple myeloma, particularly ECOG ≥ 2, immobility and higher factor VIII levels, as well as lymphoma aggressiveness, treatment with dexamethasone and the haemostatic biomarkers D-dimer and total protein S activity. Additionally, genetic variants factor V Leiden, serpinA10 rs2232698 and factor XIII-A Val34Leu warrant further investigation for use in the research setting.

Patients with multiple myeloma and monoclonal gammopathy of undetermined significance have variably increased thrombin generation and different sensitivity to the anticoagulant effect of activated protein C

BACKGROUND

Patients with multiple myeloma (MM) are at high risk of thrombosis especially when receiving immunomodulatory therapy. Thrombotic risk in patients with monoclonal gammopathy of undetermined significance (MGUS) may also be increased. Although activated protein C (APC) resistance has been linked to an increased risk of thrombosis in MM, little is known about how APC influences thrombotic risk in MGUS. We compared thrombin generation (TG) in MM and MGUS patients to that of healthy controls (HCs) and investigated the exogenous effect of APC on TG in these groups.

METHODS

Hemostasis tests including factor VIII (FVIII) and von Willebrand factor (vWF) levels were measured in platelet-poor plasma in 14 untreated MM patients, 34 MGUS patients, and 30 age and sex-matched HCs. TG assay was performed with or without the addition of APC.

RESULTS

Peak thrombin and velocity index were significantly higher in MM and MGUS patients compared to HCs, while MM patients also had elevated endogenous thrombin potential (ETP). In MGUS cases, ETP and peak thrombin values significantly correlated with FVIII and vWF levels. In the presence of APC, peak thrombin and ETP were reduced in MGUS and control plasmas whereas lagtime and time to peak were significantly prolonged. In contrast, adding APC to MM plasma had no effect on any TG parameters.

CONCLUSIONS

Hypercoagulability was observed in MM and even in MGUS cases with very low monoclonal protein concentration. In MM patients, APC had no effect on TG, but it attenuated TG in MGUS patients.

Combined effects of five prothrombotic genotypes and cancer on the risk of a first venous thromboembolic event

BACKGROUND

The role of combined prothrombotic genotypes in cancer-related venous thromboembolism (VTE) is scarcely studied. We aimed to investigate the impact of a 5-single nucleotide polymorphism (SNP) score on the risk of VTE in patients with and without cancer using a population-based case-cohort.

METHODS

Cases with a first VTE (n = 1493) and a subcohort (n = 13 072) were derived from the Tromsø Study (1994-2012) and the Nord-Trøndelag Health Study (1995-2008). Five SNPs previously reported as a risk score were genotyped: ABO (rs8176719), F5 (rs6025), F2 (rs1799963), FGG (rs2066865), and F11 (rs2036914). Hazard ratios (HRs) for VTE were estimated according to cancer status and the number of risk alleles in the 5-SNP score (0-1, 2-3, and ≥4 alleles).

RESULTS

During a median follow-up of 12.3 years, 1496 individuals were diagnosed with cancer, of whom 232 experienced VTE. The VTE risk increased with the number of risk alleles in the 5-SNP score among subjects without and with cancer. In cancer-free subjects, the HR was 2.17 (95% confidence interval [CI] 1.79-2.62) for ≥4 versus 0-1 risk alleles. In cancer patients, the corresponding HR was 1.93 (95% CI 1.28-2.91). The combination of cancer and ≥4 risk alleles yielded a 17-fold (HR 17.1, 95% CI 12.5-23.4) higher risk of VTE compared with cancer-free subjects with 0-1 risk alleles.

CONCLUSION

The risk of VTE increases with the number of prothrombotic risk alleles in subjects with and without cancer, and the combination of prothrombotic risk alleles and cancer leads to a highly elevated risk of VTE.

Acute Leriche Syndrome in Pancreatic Adenocarcinoma: A Case Report

Introduction:

Coexistance of pancreatic carcinoma and Leriche syndrome is an extremely rare pathological condition. Leriche syndrome is defined as occlusion of the distal aorta at the bifurcation into the common iliac arteries.

Case Report:

We report the case of a 57-year old male patient with a locally advanced pancreatic tumor that during chemotherapy presented Leriche syndrome. Four months after the diagnosis and although the initial staging by MRI had only revealed a few atheromatic lesions of the abdominal aorta, the patient complained about claudication of the legs and hypoesthesia. Angiography with multi-detector computed tomography (MDCTA) was performed using aortography protocol and three-dimensional reconstruction of the images followed, deCmonstrating the relationship between pancreatic carcinoma and Leriche syndrome.

:

Review of the literature revealed that acute abdominal thrombosis is rare in cancer patients. To our knowledge, complete occlusion of the aorta in a patient with pancreatic cancer has not been reported yet.

Predicting VTE in Cancer Patients: Candidate Biomarkers and Risk Assessment Models

Risk prediction of chemotherapy-associated venous thromboembolism (VTE) is a compelling challenge in contemporary oncology, as VTE may result in treatment delays, impaired quality of life, and increased mortality. Current guidelines do not recommend thromboprophylaxis for primary prevention, but assessment of the patient's individual risk of VTE prior to chemotherapy is generally advocated. In recent years, efforts have been devoted to building accurate predictive tools for VTE risk assessment in cancer patients. This review focuses on candidate biomarkers and prediction models currently under investigation, considering their advantages and disadvantages, and discussing their diagnostic performance and potential pitfalls.

Pharmacogenetics to prevent heparin-induced thrombocytopenia: what do we know?

Heparin-induced thrombocytopenia (HIT) is a life-threatening, immune-mediated adverse reaction to heparin anticoagulants. The inability to predict HIT represents a considerable liability associated with heparin administration. Genetic studies of HIT are challenging due to the scarcity of true HIT cases, potential for misclassification, and many environmental risk factors. Genetic studies have not consistently identified risk alleles for HIT, the production of platelet factor 4/heparin antibodies or the thromboembolic complications of HIT. Genes implicated in HIT and platelet factor 4/heparin antibody levels include FCGR2A, TDAG8, HLA-DR and others. Compelling evidence also suggests that the FCGR2A H131R polymorphism is associated with HIT-related thrombosis. There is a need for well-powered, multiethnic studies with laboratory confirmation of HIT, detailed patient- and drug-specific data, and inclusion of both serologic and thromboembolic outcomes. Genomic biomarkers identified from such studies offer the possibility of shifting current clinical practice paradigms from early detection and treatment to prevention.

Hematology in palliative medicine

Advanced cancer and life-limiting chronic nonmalignant diseases are associated with a number of hematological problems. Anemia and coagulation disorders, principally venous thrombosis and thrombocytopenia, are most commonly observed. Patients undergoing chemotherapy and bone marrow transplant have unique problems that include neutropenias and chemotherapy-induced drug toxicities, which will not be covered in this article.

Determinants of acquired activated protein C resistance and D-dimer in breast cancer

BACKGROUND

We have previously reported acquired activated protein C (APC) resistance and elevated plasma D-dimer levels in breast cancer patients. Here, we aimed to identify phenotypic and genetic determinants that contribute to the acquired APC resistance and increased D-dimer levels in breast cancer. Healthy controls served as reference. We also addressed whether higher APC resistance or D-dimer levels could be potential markers of clinicopathological breast cancer characteristics.

MATERIALS AND METHODS

358 breast cancer patients and 273 healthy controls were enrolled and hemostatic plasma parameters were determined; factor (F) V, FVIII, FIX, FX, fibrinogen, von Willebrand factor (VWF), normalized APC sensitivity ratio (n-APC-sr), protein C, protein S, antithrombin, tissue factor pathway inhibitor (TFPI), and D-dimer. Common single nucleotide polymorphisms were genotyped in coagulation-related genes in the breast cancer patients.

RESULTS

The phenotypic hemostatic factors explained 25% and 31% of the variability in acquired APC resistance and D-dimer levels, respectively, in the breast cancer patients. Fibrinogen (β=-0.35, P<0.001), protein C (β=0.28, P<0.001), and FIX (β=0.22, P=0.026) were identified as determinants of n-APC-sr (in FV Leiden non-carriers), whereas TFPI (β=0.28, P<0.001), antithrombin (β=-0.25, P<0.001), and FX (β=0.15, P=0.040) were the major determinants of D-dimer. Moreover, borderline higher APC resistance (>75th percentile) was found in patients with triple negative tumors (odds ratio (OR) 1.97, 95% CI 0.99-3.90).

CONCLUSIONS

This study reports phenotypic hemostatic parameters that determine acquired APC resistance and D-dimer levels in breast cancer patients. The explanatory power was modest, however, our findings are hypothesis generating and may contribute to further understand the background for cancer associated-coagulopathy and thrombosis.

Áinle F. Plasma Thrombin Generation and Sensitivity to Activated Protein C Among Patients With Myeloma and Monoclonal Gammopathy of Undetermined Significance

The etiology of the prothrombotic state in myeloma has yet to be definitively characterized. Similarly, while recent evidence suggests that patients with monoclonal gammopathy of undetermined significance (MGUS) may also be at increased risk of thrombosis, the magnitude and the etiology of this risk have also yet to be defined. The present study aims to characterize patterns of plasma thrombin generation and sensitivity to the anticoagulant activity of activated protein C (APC) at the time of initial diagnosis of myeloma and in response to therapy in comparison to that observed among patients with MGUS and matched, healthy volunteers. Patients presenting with newly diagnosed/newly relapsed myeloma (n = 8), MGUS (n = 8), and matched healthy volunteers (n = 8) were recruited. Plasma thrombin generation was determined by calibrated automated thrombography. Peak thrombin generation was significantly higher in patients with myeloma (383.4 ± 33.4 nmol/L) and MGUS (353.4 ± 16.5 nmol/L) compared to healthy volunteers (276.7 ± 20.8 nmol/L; P < .05). In the presence of APC, endogenous thrombin potential was significantly lower in control plasma (228.6 ± 44.5 nmol/L × min) than in either myeloma (866.2 ± 241.3 nmol/L × min, P = .01) or MGUS plasma (627 ± 91.5 nmol/L × min, P = .003). Within the myeloma cohort, peak thrombin generation was significantly higher at diagnosis (353.2 ± 15.9 nmol/L) than following completion of the third cycle of therapy (282.1 ± 15.2 nmol/L; P < .005). Moreover, sensitivity to APC increased progressively with each cycle of chemotherapy. Further study of the etiology and evolving patterns of hypercoagulability among patients with these conditions is warranted and may have future implications for thromboprophylaxis strategies.

Joint effects of cancer and variants in the factor 5 gene on the risk of venous thromboembolism

Venous thromboembolism occurs frequently in cancer patients. Two variants in the factor 5 gene (F5), rs6025 encoding for the factor V Leiden mutation R506Q, and rs4524 encoding K858R, have been found to be associated with venous thromboembolism. We assessed the joint effect of active cancer and these two F5 variants on venous thromboembolism risk in a case-cohort study. Cases with a first venous thromboembolism (n=609) and a randomly selected age-weighted cohort (n=1,691) were sampled from the general population in Tromsø, Norway. Venous thromboembolism was classified as cancer-related if it occurred in the period 6 months before to 2 years after a diagnosis of cancer. Active cancer was associated with an 8.9-fold higher risk of venous thromboembolism (95% CI 7.2-10.9). The risk of cancer-related venous thromboembolism was 16.7-fold (95% CI 9.9-28.0) higher in subjects heterozygous for rs6025 compared with non-carriers of this variant without active cancer. In subjects with active cancer the risk of venous thromboembolism was 15.9-fold higher (95% CI 9.1-27.9) in those with one risk allele at rs4524, and 21.1-fold (95% CI 12.4-35.8) higher in those with two risk alleles compared with non-carriers without active cancer. A synergistic interaction was observed between active cancer and factor V Leiden (relative excess risk due to interaction 7.0; 95% CI 0.5-14.4) and rs4524 (relative excess risk due to interaction 15.0; 95% CI 7.5-29.2). The incidence of venous thromboembolism during the initial 6 months following a diagnosis of cancer was particularly high in subjects with risk alleles at these loci. This implies that the combination of cancer and F5 variants synergistically increases venous thromboembolism risk.

Impact of thrombophilic genes mutations on thrombosis risk in Egyptian nonmetastatic cancer patients

Venous thromboembolism (VTE) is a common complication in cancer patients. Several genetic risk factors related to thrombophilia are known; however, their contributions to thrombotic tendency in cancer patients have conflicting results. We aimed to determine the prevalence of factor V Leiden (FVL), prothrombin (PTH) G20210A and methylene tetrahydrofolate reductase (MTHFR) C677T gene polymorphisms in Egyptian nonmetastatic cancer patients and their influence on thrombosis risk in those patients. Factor V Leiden, PTH G20210A and MTHFR C677T polymorphisms were detected in 40 cancer patients with VTE (group 1) and 40 cancer patients with no evidence of VTE (group 2) by PCR-based DNA analysis. Factor V and MTHFR mutations were higher in group 1 than in group 2 (factor V heterozygous mutation: 20 vs. 7.5%, homozygous mutation: 10 vs. 2.5%; MTHFR heterozygous mutation: 40 vs. 25%, homozygous mutation 5 vs. 0%, respectively) (P = 0.03). Mortality rate was higher in group 1 (75%) than in group 2 (25%; P < 0.001). No difference was found between those groups regarding PTH mutation (P = 1). Mortality rate was higher in the presence of homozygous and heterozygous factor V mutation (100 and 82%, respectively) compared to the wild type (41%) (P = 0.0006). Having any of the three studied gene mutations worsened the overall survival (P = 0.0003). Cox regression proved that both thrombosis and presence of factor V mutation are independent factors affecting survival in cancer patients (P < 0.001 and P = 0.01, respectively). In conclusion, there is an association between factor V and MTHFR mutations and risk of VTE in Egyptian cancer patients. Thrombosis and presence of factor V mutation are independent factors that influence survival in those patients.

Factor V Leiden 1691G/A and prothrombin gene 20210G/A polymorphisms as prothrombotic markers in adult Egyptian acute leukemia patients

Factor V Leiden 1691G/A and prothrombin gene 20210G/A mutations are the most common genetic defects leading to thrombosis. This work aimed to study the FV Leiden and the prothrombin gene polymorphism in adult Egyptian patients with acute leukemia and their importance in thrombophilia screening. The study included 76 patients with acute leukemia and 100 healthy controls. Genotyping was done by real-time polymerase chain reaction technique. For factor V Leiden, the frequency of G/A mutation conferred more than 2.5-fold of increased risk of (OR 2.639 95 % CI 1.045-6.669). The frequency of factor V Leiden combined (G/A + A/A) genotypes conferred 2.83-fold of increased risk (OR 2.828, CI 1.13-7.075), The A allele conferred almost threefold increased risk (OR 2.824, 95 % CI 1.175-6.785). Despite higher frequency in patients compared to controls, there was no risk of association between prothrombin gene mutation and acute leukemia in adult Egyptians nor was there between combined genotypes of prothrombin gene mutation and factor V Leiden.

Contributing role of extracellular vesicles on vascular endothelium haemostatic balance in cancer

Extracellular vesicles (EVs) generated during tumourigenesis are thought to play a major role in the hypercoagulant state observed in cancer patients. They exhibit negatively charged phospholipids and tissue factor (TF) that promote coagulation cascade activation. In addition, they contain surface proteins and cytoplasmic molecules, both originating from the producing cell that can impact target cells’ expression. By targeting endothelial cells of blood vessels, these EVs could disturb the physiological anticoagulant properties of these cells and be partly responsible for the vascular endothelium activation observed in cancer patients. Indeed, vascular endothelium naturally exhibits heparin-like proteoglycan, TF pathway inhibitor and protein C anticoagulant pathway that prevent thrombosis in physiological condition. An overexpression of TF and a decreased expression of coagulation cascade inhibitors have been reported after EVs’ treatment of endothelial cells. The induction of apoptosis and an increased expression of platelet adhesion molecules have also been highlighted. These events may promote thrombus formation in cancer. The aim of this paper is to provide a targeted review on the current evidence and knowledge of roles and impact of EVs on endothelial surface anticoagulant and procoagulant factors and cellular adhesion molecules expression.

Thrombosis in multiple myeloma

Multiple myeloma, as with other malignancies, has been associated with the development of venous thromboembolic events. Chemotherapy or steroids in combination with antiangiogenic agents can further enhance this risk. The identification of measurable factors associated with this prothrombotic state could help in the selection of patients who need antithrombotic prophylaxis. Malignancy-associated thrombophilic state, paraprotein-specific mechanisms and treatment-induced changes can explain the high rate of thrombosis in this cancer population. While the release of inflammatory cytokines induces high levels of factor VIII, von Willebrand factor and downregulate the protein C system, elevated plasma immunoglobulin can impair fibrinolysis. Strategies of thromboprophylaxis with low molecular weight heparin, warfarin or aspirin in patients treated with thalidomide/chemotherapy or lenalidomide and dexamethasone have shown efficacy. Early data indicate that the effect of low molecular weight heparin on multiple myeloma is not confined to the anticoagulant effect but could extend to survival; a similar positive trend in overall survival has also been reported in patients treated with aspirin.

Pulmonary embolism as the first manifestation of multiple myeloma

Multiple myeloma is considered a hypercoagulable state due to several mechanisms such as the increased IL-6 and immunoglobulins production, the defective fibrinolytic mechanism, and the acquired resistance to activated protein C that are involved in the pathogenesis and clinical futures of the disease. We describe a case of a female patient who presented to the hospital with pulmonary embolism as the first manifestation of the hypercoagulability of multiple myeloma.

Impact of chemotherapy on activated protein C-dependent thrombin generation--association with VTE occurrence

Chemotherapy has been associated with an increased risk of venous thromboembolism (VTE). However, the prevalence of coagulation abnormalities or VTE occurrence as a consequence of different anti-cancer agents or treatment schemes is largely uncharacterized. Thus, this study was aimed at analyzing the impact of different anticancer drugs on the prothrombotic status of cancer out-patients scheduled for chemotherapy. To this purpose, a mono-institutional study was prospectively conducted to monitor serial changes of activated protein C (APC) function in 505 consecutive cancer out-patients with primary or relapsing solid cancer at the start of a new chemotherapy regimen. The results obtained showed that age >65 years (p = 0.01), ECOG performance status (p = 0.01), platinum-based (p = 0.035) and fluoropyrimidine-based regimens (p = 0.008) were independent predictors of an acquired APC resistance during the first chemotherapy cycle. Multivariate model of Cox proportional hazards survival analysis demonstrated that a decline in APC functionality (HR = 2.4; p = 0.013) and platinum-based regimens (HR = 2.2; p = 0.042) were both capable of predicting the occurrence of a first VTE episode during chemotherapy. Indeed, 14% of patients with platinum-associated APC impairment had VTE over a 1-year follow-up, compared to 3% of patients treated with other regimens and in whom APC functionality remained stable (HR = 1.5; p = 0.003). We may, thus, conclude that use of platinum-based regimens is responsible for induction of an acquired thrombophilic condition and represents a predictor for VTE even after adjustment for other risk factors.

Association between increased tumor necrosis factor alpha levels and acquired activated protein C resistance in patients with metastatic colorectal cancer

PURPOSE

The purpose of this study was to investigate the possible association between tumor necrosis factor-α (TNF-α) levels and defects in the activated protein C (APC) system as a determinant of venous thromboembolism (VTE) in metastatic colorectal cancer patients (mCRC) undergoing chemotherapy.

METHODS

TNF-α levels (measured by immunoassay) and abnormalities in the APC system [evaluated by an APC-dependent thrombin generation assay (ThromboPath-ThP)] were evaluated in 45 mCRC patients undergoing chemotherapy. VTE events were recorded during follow-up.

RESULTS

TNF-α levels were increased (p < 0.01), and APC functionality was decreased (p < 0.0001) in mCRC patients compared to age- and sex-matched controls. An inverse correlation was observed between TNF-α and APC impairment in mCRC (p < 0.0001). TNF-α was confirmed as an independent predictor (p = 0.007) for APC abnormalities at multivariate regression analysis. Nine (20 %) of 45 mCRC patients experienced VTE during chemotherapy. Bayesian analysis of combined ThP/TNF-α showed a positive predictive value of 0.67 in predicting VTE (p = 0.01). Cox proportional hazards survival analysis confirmed the predictive value of combined ThP/TNF-α determination in VTE risk assessment of mCRC patients (either negative vs. both positive: HR = 0.02; p = 0.001), and Kaplan-Meier analysis demonstrated that mCRC patients with either negative TNF-α or ThP values prior to chemotherapy were less likely to experience VTE (13 %) than patients with abnormalities of both markers (67 %, p = 0.002).

CONCLUSIONS

These results suggest that the host inflammatory response to cancer cells and/or tumor-derived cytokines could be responsible for an impairment of the APC system and a switch toward a pro-thrombotic state, which might predispose to the occurrence of VTE in mCRC patients undergoing chemotherapy.

Factor V Leiden and Prothrombin 20210A Mutations among Turkish Pediatric Leukemia Patients

This study was undertaken to determine the prevalence of the Factor V 1691 G-A and PT 20210 G-A mutations in Turkish children with leukemia. We genotyped 135 pediatric leukemia patients with for these mutations. Eleven (8%) of the 135 patients were heterozygous for the FV 1691 G-A mutation. Seven (5,1%) of the patients carried the PT 20210 G-A heterozygous mutation. Of the 135 patients, only three had thrombotic event, none of which had these two mutations, which is common in Turkish population. Our findings revealed a controversial compared to the previous reports, which needs further investigation.

Heparanase-A Link between Coagulation, Angiogenesis, and Cancer

Heparanase that was cloned from and is abundant in the placenta is implicated in cell invasion, tumor metastasis, and angiogenesis. Recently we have demonstrated that heparanase may also affect the hemostatic system in a non-enzymatic manner. Heparanase was shown to up-regulate tissue factor (TF) expression and interact with tissue factor pathway inhibitor (TFPI) on the cell surface, leading to dissociation of TFPI from the cell membrane of endothelial and tumor cells, resulting in increased cell surface coagulation activity. More recently, we have shown that heparanase directly enhances TF activity, resulting in increased factor Xa production and activation of the coagulation system. Data indicate increased levels and possible involvement of heparanase in vascular complications in pregnancy. Taking into account the prometastatic and proangiogenic functions of heparanase, overexpression in human malignancies, and abundance in platelets and placenta, its involvement in the coagulation machinery is an intriguing novel arena for further research.

Activated protein C resistance as measured by residual factor V after Russell's viper venom and activated protein C treatment analyzed as a continuous variable in multiple myeloma and normal controls

Increased risk of venous thromboembolism (VTE) has been described in multiple myeloma patients, particularly when exposed to immunomodulatory drugs. Epidemiological studies have shown that monoclonal gammopathy of undetermined significance (MGUS) patients also have an increased risk of VTE compared with normal individuals. Acquired activated protein C resistance (APC-R) is an independent risk factor for VTE in hematologic malignancies. We reviewed the records of patients with multiple myeloma and MGUS for APC-R by PEFAKIT APC-R test and compared them to normal individuals. We excluded from the analysis patients with a documented factor V Leiden mutation. The PEFAKIT APC-R is a plasma-based functional prothrombin assay based on ratio of patient clotting time with and without APC. Thirty-three MGUS and 93 multiple myeloma patients were compared with 39 normal individuals. Baseline characteristics from the three groups were similar in terms of age, sex, and performance status. The median APC-R for multiple myeloma, MGUS, and controls were 1, 1.06, and 1.1, respectively. Multiple myeloma patients compared to normal individuals had significantly shorter APC-R (P=0.0012). No significant difference was observed between MGUS and normal individuals (P=0.17). After analyzing APC-R values and multiple coagulation parameters, a significant inverse correlation was found between APC-R and fibrinogen (P=0.0000001) and D-dimer (P=0.045) serum levels and a direct correlation with prothrombin time value (P=0.034). The Pefakit APC-R test measured as continuous variable shows a statistically significant decrease in patients with myeloma compared to normal individuals.

Heparanase procoagulant effects and inhibition by heparins

Heparanase is an endo-beta-D-glucuronidase capable of cleaving heparan sulfate (HS) side chains of heparan sulfate proteoglycans (HSPG) on cell surfaces and the extracellular matrix, activity that is strongly implicated in tumor metastasis and angiogenesis. Evidence was provided that heparanase over-expression in cancer cells results in a marked increase in tissue factor (TF) levels. Likewise, TF was induced by exogenous addition of recombinant heparanase to tumor cells and primary endothelial cells, induction that was mediated by p38 phosphorylation and correlated with enhanced procoagulant activity. TF induction was further confirmed in heparanase over-expressing transgenic mice and correlated with heparanase expression levels in leukemia patients. Heparanase was also found to be involved in the regulation of tissue factor pathway inhibitor (TFPI). A physical interaction between heparanase and TFPI was demonstrated, suggesting a mechanism by which secreted heparanase interacts with TFPI on the cell surface, leading to dissociation of TFPI from the cell membrane and increased coagulation activity, thus further supporting the local pro-thrombotic function of heparanase. Data indicate a possible involvement of heparanase in early miscarriages and point to a regulatory effect on TFPI and TFPI-2 in trophoblasts. As heparins are strong inhibitor of heparanase, in view of the effect of heparanase on TF, the role of heparins anticoagulant-activity may potentially be expanded. Taking into account the pro-metastatic and pro-angiogenic functions of heparanase, its over-expression in human malignancies and abundance in platelets, its involvement in the coagulation machinery is an intriguing novel arena for further research.

Heparanase coagulation and cancer progression

Heparanase is an endo-beta-D-glucuronidase capable of cleaving heparan sulphate (HS) side chains of heparan sulphate proteoglycans on cell surfaces and the extracellular matrix; activity that is strongly implicated in tumour metastasis and angiogenesis. It has been shown that heparanase overexpression in human leukaemia, glioma and breast carcinoma cells results in a marked increase in tissue factor (TF) levels. In addition, TF was induced by exogenous addition of recombinant heparanase to tumour cells and primary endothelial cells; induction that was mediated by p38 phosphorylation and correlated with enhanced procoagulant activity. TF induction was further confirmed in transgenic mice overexpressing heparanase, and correlated with heparanase expression levels in leukaemia patients. Heparanase was also found to be involved in the regulation of tissue factor pathway inhibitor (TFPI). It has been shown that heparanase overexpression or exogenous addition induces a two- to three-fold increase in TFPI expression. Similarly, heparanase stimulated accumulation of TFPI in the cell culture medium. However, extracellular accumulation exceeded the observed increase in TFPI at the protein level, and appeared to be independent of HS and heparanase enzymatic activity. Instead, a physical interaction between heparanase and TFPI was demonstrated, suggesting a mechanism by which secreted heparanase interacts with TFPI on the cell surface, leading to dissociation of TFPI from the cell membrane and increased coagulation activity, thus further supporting the local prothrombotic function of heparanase. As heparins are strong inhibitors of heparanase, in view of the effect of heparanase on the TF/TFPI pathway, the role of anticoagulant activity of heparin may potentially be expanded. Taking into account the prometastatic and pro-angiogenic functions of heparanase, its overexpression in human malignancies and abundance in platelets, its involvement in the coagulation machinery is an intriguing novel arena for further research.

Increased acquired activated protein C resistance in unselected patients with hematological malignancies

BACKGROUND

We have previously found that activation of coagulation in patients with various hematological malignancies was apparently not initiated by tissue factor (TF). Acquired activated protein C (APC) resistance may be another mechanism responsible for such hypercoagulation, and has been demonstrated in patients with solid tumors, but not in patients with hematological malignancy.

OBJECTIVE

To investigate acquired APC resistance in a hypercoagulable cohort of patients with hematological malignancies.

PATIENTS/METHODS

Blood samples from 93 patients with acute myeloid leukemia (AML), chronic lymphatic leukemia, multiple myeloma, or non-Hodgkin's lymphoma, were analyzed before start and after completion of cancer therapy. APC resistance was measured using calibrated automated thrombography. The APC sensitivity ratio (APC-SR) was calculated as the ratio of the endogenous thrombin potential (ETP) determined in plasma probed with either APC or buffer.

RESULTS

Untreated patients were found to have higher APC-SR than healthy controls, and patients with AML had higher APC-SR as compared to the other diagnoses, both findings being consistent with acquired APC resistance. The acquired APC resistance was partly ameliorated with cancer treatment. Decreased levels of protein S and TF pathway inhibitor were inversely correlated to APC resistance.

CONCLUSIONS

APC resistance may contribute to the hypercoagulable state in hematological malignancies.

Granulomatous reaction in mediastinal B-cell non-Hodgkin lymphoma and intracardiac thrombosis

Epithelioid cell granulomas may be associated with several neoplasms. Lymphomas may mimic or are associated with epithelioid granulomas. In this article the authors report a child with granulomatous reaction in B cell non-Hodgkin lymphoma and intracardiac thrombosis. Although cancer alone is a risk factor for thromboembolism, thrombosis is a multifactorial disorder with both hereditary and acquired risk factors. This is the first reported case of intracardiac thrombosis with MTHFR A1298C and factor XIII V34L mutations together with granulomatous reaction in non-Hodgkin lymphoma.

Thrombophilia and risk of venous thrombosis in patients with cancer

Venous thrombosis is a common and severe complication in patients with cancer. We reviewed studies assessing whether a state of acquired or congenital thrombophilia influenced the risk of thrombosis in patients with cancer. The results are equivocal. However, the majority of studies were of limited size. The influence of thrombophilia in patients with cancer may be more difficult to demonstrate than in the general population, the risk of thrombosis due to cancer per se possibly outweighing the contribution of thrombophilic factors. Moreover, the results may depend on the genetic background of the population, the type of cancer, the type of thrombosis, and the chemotherapeutic treatment. Nevertheless, it appears that factor V Leiden or G20210A prothrombin gene mutation increases the risk of venous thromboembolism about 2- to 4-fold, compared with patients with cancer without either of these mutations. Similar results were observed for the occurrence of central venous catheter-associated thrombosis. Antiphospholipid antibodies and acquired resistance to activated protein C were frequently observed in patients with cancer and appeared to favor the occurrence of thrombosis. The role of hyperhomocysteinemia deserves further investigation. Since the clinical implications of these findings remain to be clarified, routine screening of cancer patients for thrombophilia cannot yet be recommended on the basis of these studies. Studies designed to assess the value of thromboprophylaxis in high-risk patients, including thrombophilic patients, with long-term central venous catheters may be valuable.

Activated Protein C Resistance and Factor V Leiden in Mexico

A common cause of hereditary thrombophilia is activated protein C resistance (APCR), and most cases result from factor V Leiden mutation. An APCR phenotype without association with factor V Leiden has been described. This transversal, observational, nonrandomized study evaluated these 2 phenomena in healthy indigenous and mestizo Mexican subjects (n = 4345), including 600 Mexican natives. No indigenous subjects had APCR, but 82 mestizo subjects did. After retesting, 50 subjects had a negative test. The remaining 32 subjects had factor V Leiden, giving a 0.85% prevalence of factor V Leiden in the mestizo Mexican population. Only 31% of APCR carriers had factor V Leiden. These results show a very low prevalence of APCR and factor V Leiden in Mexico. Except for factor V Leiden, there are no other mutations in the factor V gene responsible for the APCR phenotype. Acquired APCR is nearly twice as prevalent as the inherited variant.

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.

Bleeding and Thrombosis Risks in Plasma Cell Dyscrasias

Major, spontaneous bleeding is uncommon in patients with plasma cell dyscrasias despite frequent abnormal screening hemostasis tests. However, acquired von Willebrand deficiency and light-chain (AL) amyloidosis, and amyloidosis complicating multiple myeloma can present with serious hemorrhagic complications that are challenging to manage. While patients with monoclonal gammapathy of undetermined significance and multiple myeloma share an intrinsic increased risk of venous thromboembolic events (VTE), treatment with thalidomide and lenalidomide increases the incidence of VTE in certain multiple myeloma patient subsets. Our understanding of the complex interactions among malignant plasma cells, inflammatory and hemostasis pathways, and treatment modalities that combine to produce thrombotic complications is incomplete. Prospective, randomized trials are clearly needed to assist clinicians in providing optimal VTE prophylaxis to their patients with plasma cell dyscrasias.

Prevalence of Factor V 1691 G–A (Leiden) and prothrombin G20210A polymorphisms and the risk of venous thrombosis among cancer patients

AIMS

Cancer patients have an increased risk for thromboembolism (TE). Factor V 1691 G-A(Leiden) (FVL) and prothrombin (PT) G20210A mutation are common inherited risk factor for TE. The aim of the study is to evaluate the prevalence of FVL and PT G20210A polymorphism in cancer patients with and without TE as compared to patients with TE without malignancy and healthy control.

MATERIALS AND METHODS

We have studied 43 cancer patients who developed TE during cancer treatment (group 1); 81 cancer patients without TE (group 2); 100 patients with TE without malignancy (group 3); 100 healthy control (group 4). FVL and PT G20210A polymorphisms were determined by the method of polymerase chain reaction-based DNA analysis.

RESULTS

The prevalence of FVL was significantly greater in cancer patients with TE (13 of 43, 30.2%) compared with other groups: 3.7% in group 2; 18% in group 3; 8% in group 4 (P < 0.0001). There was no significant difference in the prevalence of PT G20210A among the groups (P > 0.05).

CONCLUSIONS

The study suggested that cancer patients with TE should be evaluated for FVL but PT G20210A was not contributing factor to the development of TE during cancer therapy.

Acquired resistance to activated protein C (aAPCR) in multiple myeloma is a transitory abnormality associated with an increased risk of venous thromboembolism

Acquired activated protein C resistance (aAPCR), not associated with factor V Leiden, has been described in cancer patients with an increased risk of venous thromboembolism (VTE). APCR was determined in 1178 myeloma patients using an activated partial thromboplastin time-based resistance assay in the presence of excess of factor V-deficient plasma; polymerase chain reaction amplification of genomic DNA was used to detect factor V Leiden mutation. A total of 109 patients were found to have abnormal APCR and one-third of them were carriers for the mutation. With a median follow-up of 40 months, the presence of aAPCR was associated with a significantly increased risk of thrombosis (P < or = 0.001). APCR was measured again after treatment in 31 patients with abnormal baseline values and had normalised in 30 of them. This study indicates that aAPCR is the most common single transitory baseline coagulation abnormality associated with VTE in myeloma patients.

Recurrent pulmonary embolism and pulmonary hypertension in chronic tetraplegia

STUDY DESIGN

Case report.

OBJECTIVE

To describe an unusual case of progressive pulmonary hypertension due to recurrent pulmonary embolism in a chronically paralyzed spinal cord injury patient.

SETTING

Veterans Administration Hospital, West Roxbury, MA, USA.

SUBJECT

A 57-year-old man, tetraplegic, sensory incomplete and motor complete for 30 years due to a diving accident, complained of lightheadedness and shortness of breath intermittently for 7 years. Examination during the latest episode revealed anxiety, confusion, respirations 28 per min, blood pressure 80/60 mmHg, and arterial pH 7.41, P(CO2) 28 mmHg, P(O2) 95 mmHg on 2 l of oxygen. A chest film 2 weeks earlier had revealed a right-sided cutoff of pulmonary vasculature; the current film showed right-sided pleural effusion. Review of EKGs showed a trend of increasing right axis deviation with recovery and recurrences during the previous 9 years and a current incomplete right bundle branch block with clockwise rotation and inverted T waves in V1-4. Computerized tomography with contrast material revealed small pulmonary emboli, but only in retrospect. The patient died shortly after scanning.

AUTOPSY

The pulmonary arteries were free of thromboemboli on gross examination but medium and small-sized arteries were constricted or obliterated with thrombotic material microscopically. The estimated ages of the thromboemboli ranged from days to years. The right ventricle was hypertrophied; the coronary arteries were patent.

CONCLUSION

Recurrent pulmonary emboli resulted in chronic pulmonary hypertension and eventual death in a patient with chronic tetraplegia.

Factor V Leiden, prothrombin 20210A and the risk of venous thrombosis among cancer patients

Cancer patients have an increased risk of venous thrombosis (VT). The association of factor V Leiden (FVL) and the prothrombin 20210A variant with VT in cancer patients is not established. We genotyped 101 cancer patients with VT and 101 cancer patients without VT for these polymorphisms. Five cases and three controls were heterozygous for FVL, yielding an odds ratio of 1.7 (95% confidence interval (CI) 0.3-10.7). Five cases and no controls were heterozygous for prothrombin 20210A, for an odds ratio of 6.7 (95% CI 0.9-infinity). Prothrombin 20210A may be associated with VT risk among cancer patients.

Venous sonography for the diagnosis of asymptomatic deep vein thrombosis in patients with cancer undergoing chemotherapy

OBJECTIVE

Early detection of asymptomatic deep vein thrombosis by venous sonography may identify patients who may benefit from anticoagulant therapy and thus may prevent morbidity and mortality associated with deep vein thrombosis. The aim of this study was to examine the prevalence of deep vein thrombosis by venous sonography in asymptomatic ambulatory patients with cancer undergoing chemotherapy and to evaluate the correlation between procoagulant activity and asymptomatic deep vein thrombosis.

METHODS

The study population included 62 patients (32 with lung cancer and 30 with lymphoma) receiving chemotherapy with an ambulatory performance status and without clinical evidence of deep vein thrombosis. Bilateral venous sonographic studies of the lower extremities were performed, covering the femoropopliteal venous system. The D-dimer level and acquired activated protein C resistance were determined in the patients and in 30 healthy control subjects.

RESULTS

Sonographic evidence of deep vein thrombosis on the femoropopliteal axis was found in 0 (0%) of 62 patients (1-sided 95% confidence interval, 0%-4.8%). Acquired activated protein C resistance prevalence and D-dimer levels were increased in study patients compared with control subjects (34% versus 0%; P < .003; median, 0.72 versus 0.25 mg/L; P < .0001, respectively).

CONCLUSIONS

Despite the procoagulant tendency, venous sonography did not detect asymptomatic deep vein thrombosis in patients with cancer undergoing chemotherapy. Thus, screening by venous sonography is not justified in this patient population.

Haemostatic changes in pregnancy

In normal pregnancy, there is a marked increase in the procoagulant activity in maternal blood characterized by elevation of factors VII, X, VIII, fibrinogen and von Willebrand factor, which is maximal around term. This is associated with an increase in prothrombin fragments (PF1+2) and thrombin-antithrombin complexes. There is a decrease in physiological anticoagulants manifested by a significant reduction in protein S activity and by acquired activated protein C (APC) resistance. The overall fibrinolytic activity is impaired during pregnancy, but returns rapidly to normal following delivery. This is largely due to placental derived plasminogen activator inhibitor type 2 (PAI-2), which is present in substantial quantities during pregnancy. D-dimer, a specific marker of fibrinolysis resulting from breakdown of cross-linked fibrin polymer by plasmin, increases as pregnancy progresses. Overall, there is a 4- to 10-fold increased thrombotic risk throughout gestation and the postpartum period. Local haemostasis at the placental throphoblast level is characterized by increased tissue factor (TF) expression and low expression of the inhibitor TFPI. Microparticles derived from maternal endothelial cells and platelets, and from placental throphoblasts may contribute to the procoagulant effect. Local anticoagulant mechanisms on placental throphoblasts are important for counterbalance of the procoagulant milieu. Disruption of anticoagulant mechanisms, for example, autoantibodies, to annexin V may increase pregnancy complications in patients with antiphospholipid antibodies (APLA).