Thrombophilia: common questions on laboratory assessment and management

Thrombophilia Screening: Not So Straightforward

Although inherited thrombophilias are lifelong risk factors for a first thrombotic episode, progression to thrombosis is multifactorial and not all individuals with inherited thrombophilia develop thrombosis in their lifetimes. Consequently, indiscriminate screening in patients with idiopathic thrombosis is not recommended, since presence of a thrombophilia does not necessarily predict recurrence or influence management, and testing should be selective. It follows that a decision to undertake laboratory detection of thrombophilia should be aligned with a concerted effort to identify any significant abnormalities, because it will inform patient management. Deficiencies of antithrombin and protein C are rare and usually determined using phenotypic assays assessing biological activities, whereas protein S deficiency (also rare) is commonly detected with antigenic assays for the free form of protein S since available activity assays are considered to lack specificity. In each case, no single phenotypic assay is capable of detecting every deficiency, because the various mutations express different molecular characteristics, rendering thrombophilia screening repertoires employing one assay per potential deficiency, of limited effectiveness. Activated protein C resistance (APCR) is more common than discrete deficiencies of antithrombin, protein C, and protein S and also often detected initially with phenotypic assays; however, some centres perform only genetic analysis for factor V Leiden, as this is responsible for most cases of hereditary APCR, accepting that acquired APCR and rare F5 mutations conferring APCR will go undetected if only factor V Leiden is evaluated. All phenotypic assays have interferences and limitations, which must be factored into decisions about if, and when, to test, and be given consideration in the laboratory during assay performance and interpretation. This review looks in detail at performance and limitations of routine phenotypic thrombophilia assays.

Connecting impaired fibrinolysis and dyslipidemia

A State of the Art lecture entitled "Connecting Fibrinolysis and Dyslipidemia" was presented at the International Society on Thrombosis and Haemostasis Congress 2023. Hemostasis balances the consequences of blood clotting and bleeding. This balance relies on the proper formation of blood clots, as well as the breakdown of blood clots. The primary mechanism that breaks down blood clots is fibrinolysis, where the fibrin net becomes lysed and the blood clot dissolves. Dyslipidemia is a condition where blood lipid and lipoprotein levels are abnormal. Here, we review studies that observed connections between impaired fibrinolysis and dyslipidemia. We also summarize the different correlations between thrombosis and dyslipidemia in different racial and ethnic groups. Finally, we summarize relevant and new findings on this topic presented during the 2023 International Society on Thrombosis and Haemostasis Congress. More studies are needed to investigate the mechanistic connections between impaired fibrinolysis and dyslipidemia and whether these mechanisms differ in racially and ethnically diverse populations.

Impact of SERPINC1 mutation on thrombotic phenotype in children with congenital antithrombin deficiency-first analysis of the International Society on Thrombosis and Haemostasis pediatric antithrombin deficiency database and biorepository

BACKGROUND

The natural history and genotype-phenotype correlation of congenital antithrombin (AT) deficiency in children are unknown.

OBJECTIVES

To describe the clinical presentation of congenital AT deficiency in children and evaluate its correlation to specific mutations in SERPINC1.

METHODS

In 2017, a prospective pediatric database and DNA biorepository for congenital AT deficiency was established. During the pilot phase, the database was opened at 4 tertiary care centers in Canada and US. Approval from research ethics board was obtained at each participating center. Written consent/assent was obtained from guardians/subjects who met eligibility. Demographic/clinical data were uploaded into a database. DNA extraction and SERPINC1 sequencing were centralized for US centers. Standard statistical methods were used to summarize parameters. Probability of VTE-free survival was assessed using the Kaplan-Meier method.

RESULTS

Overall, 43 participants (25 females) from 31 unique kindreds were enrolled. Median age (range) at enrollment was 14.8 years (1-21 years). Median AT activity was 52% (24%-87%), and median AT antigen (n = 20) was 55% (38%-110%). Nineteen (44%) participants had a history of venous thromboembolism (VTE). Median age at VTE diagnosis was 12.8 years (0.1-19.2 years). SERPINC1 sequencing was completed for 31 participants and 21 unique mutations were identified, including 5 novel variants. Probability of 5-year VTE-free survival (95% CI) for carriers of missense mutations (92.0% [95% CI: 71.6%-97.9%]) was significantly higher compared with carriers of null mutations (66.7% [95% CI: 19.5%-90.4%]); p = .0012.

CONCLUSION

To our knowledge, this is the first pediatric study to document a severe thrombotic phenotype in carriers of null mutations in SERPINC1, when compared with carriers of missense mutations; underscoring the importance of genetic testing.

A Prospective Study to Determine the Predictive Ability of HDP-Gestosis Score for the Development of Pre-eclampsia

Background

HDP-gestosis score is a risk scoring system (score 1-3) for the development of pre-eclampsia. When a pregnant woman's total score is equal to or greater than 3, she is labelled as "at risk for pre-eclampsia" and is managed accordingly.

Objectives

To determine the sensitivity, specificity, Positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy of HDP-gestosis score for predicting pre-eclampsia.

Methods

This prospective study included 473 pregnant women who presented at the department of Obstetrics and Gynaecology, from June 2020 to December 2021. After 20 weeks of pregnancy, the patients were assessed for the development of pre-eclampsia. Details of age, gravida, obstetric history, menstrual cycle regularity, polycystic ovarian disease history, duration of marriage, parity, past medical and surgical intervention, previous/present medication, and family history were taken. Gestosis score was calculated and classified into mild (score of 1), moderate (score of 2) and high risk (score of ≥ 3) for the development of Pre-eclampsia (PE). Sensitivity, Specificity, PPV, NPV and diagnostic accuracy of HDP-gestosis score for predicting the development of PE were determined.

Results

The mean age, gestational age, and BMI of the women were 28.4 ± 6.8 years, 11.5 ± 2.04 weeks, and 24.5 ± 3.7 kg/m^2, respectively. The gestosis score was 2 in 43.13% of the participants, 1 in 42.28%, and ≥ 3 in 14.59% of the women. PE developed in 15.01% (n = 71) participants. The Sensitivity, Specificity, PPV, NPV, and Diagnostic accuracy of HDP-gestosis score for predicting PE were 83.1%, 97.51%, 85.51%, 97.03% and 95.35%, respectively.

Conclusion

Gestosis score is a novel early marker for prediction of the development of PE allowing for a prompt management for the patients, thereby curbing the adverse consequences.

Perioperative Management of Orthopaedic Patients with Hematologic Disorders: A Critical Analysis Review

Perioperative management of orthopaedic patients with a hematologic disorder is a complex endeavor that requires a multidisciplinary team-based approach. A team composed of an experienced orthopaedic surgeon, an anesthesiologist, and a hematologist is necessary to achieve optimal outcomes. Patients with hemophilia and other complex hematologic disorders should be managed at, or in consultation with a hematologist at, a comprehensive hemophilia center. Bleeding disorders and inherited thrombophilia present unique challenges for the perioperative management of orthopaedic surgery. Comprehensive preoperative planning and familiarity with treatment guidelines can help to minimize these risks. Knowledge of the disease processes outlined in this article will provide orthopaedic surgeons with the requisite background knowledge that is needed to initiate safe and effective treatment strategies involving this high-risk patient population.

Changes in Biomarkers of Coagulation, Fibrinolytic, and Endothelial Functions for Evaluating the Predisposition to Venous Thromboembolism in Patients With Hereditary Thrombophilia

The changes in the coagulation, fibrinolytic, and endothelial functions are correlated with the pathophysiology of the thromboembolic diseases during acute illness. However, these changes in patients with hereditary thrombophilia who were not in the acute stage of venous thromboembolism (VTE) are unclear. A panel of 4 biomarkers, including thrombin–antithrombin complex (TAT), plasmin-α2-plasmin inhibitor complex (PIC), tissue-type plasminogen activator/plasminogen activator inhibitor-1 complex (t-PAIC), and soluble thrombomodulin (sTM), were assayed in 100 healthy controls and 100 patients with thrombophilia. Although significantly higher concentrations of TAT, PIC, t-PAIC, and sTM were observed in patients with thrombophilia than in healthy controls, 70 patients showed absolutely normal levels of the above 4 biomarkers. Among the other 30 patients who had at least 1 biomarker out of the corresponding reference interval, 26 of them presented elevated PIC with or without increased TAT. Except for sTM, other 3 biomarkers did not show significant differences in patients with previous VTE compared to those without. Patients with single episode of VTE had obviously lower t-PAIC than those with multiple episodes of VTE, whereas the levels of TAT, PIC, and sTM were unassociated with the number of thrombosis episodes. Most thrombophilia patients who were not in the acute stage of VTE showed normal coagulation, fibrinolytic, and endothelial functions. Thus, we were unable to show that the one-time response of this panel was clinically helpful in determining thrombosis risk in thrombophilia individuals. Future studies should focus on the dynamic monitoring during the chronic phase of VTE to offer special advantages for patients with thrombophilia.

Trends of Ordering Hypercoagulability Work-Up at an Academic Medical Center

Background

Venous thromboembolism is a significant clinical event, with an annual incidence of 1–2 per 1000 population. Risk factors include recent surgery, prolonged immobility, oral contraceptive use, and active cancer. Inherited risks include protein C and S deficiencies, antithrombin deficiency, factor V Leiden mutation and prothrombin. These factors can be tested to guide therapy, but current evidence suggests that testing for inherited thrombophilia is not recommended in most inpatient settings. In the era of high value care, hypercoagulable testing for VTE creates a financial burden for the hospital and patients. We performed a retrospective chart review of hypercoagulable orders on VTE patients at our institution.

Methods

Institutional Review Board approval was obtained. A total of 287 adult patients admitted over a 3-month period with the diagnosis of VTE were included. Patients were identified via ICD-10 codes and data were collected from electronic medical records. Patient characteristics, provoked versus unprovoked VTE, and relative contraindications for hypercoagulability work-up were analyzed. Our primary outcome was to assess the appropriateness of thrombophilia testing in VTE patients based on screening guidelines. Our secondary outcome was to analyze the cost burden of ordering these tests.

Results

A total of 287 patients were included in our data analysis. Patient risk factors for VTE were malignancy, previous DVT, immobilization, surgery 3 months prior, and central line placement. Fifty-seven of 287 patients had at least one hypercoagulable test ordered during hospitalization which did not adhere to guidelines. Misuse of testing occurred during active thrombosis, active anticoagulation, presence of risk factors, first episode of VTE, and malignancy. The cost of ordering these 5 thrombophilia tests totaled over $40,000.

Conclusion

In our study, numerous patients were tested without compliance to standard recommendations, which created financial and value-based burdens on our health care system. Increased awareness among clinicians is thus warranted to ensure high value care.

Proteome Analysis of Urinary Biomarkers in Acute Hypercoagulable State Rat Model

Thrombotic diseases are usually preceded by a hypercoagulable state in the body. This study aimed to screen potential urinary biomarkers for hypercoagulable state based on proteome analysis. Wistar rats were administered with the hemostatic agent etamsylate to establish hypercoagulable state. Urine samples were collected for proteome analysis. We found 20 proteins with levels more than 1.5-fold in difference between control rats and model rats. We searched human homologs of 20 rat proteins and identified 13 human proteins. Of the 13 human homologous proteins, nine were members of human core urinary proteome. Human homologous proteins of differential proteins were highly expressed in 31 human tissues, especially in the kidneys followed by digestive system and reproductive system. Surprisingly, we did not identify known coagulation factors as differential proteins in the urine of model rats. Hypercoagulable state of the body may not involve direct changes in coagulation factors but causes the changes upstream of the coagulation cascade system. Common differential urinary proteins between different hypercoagulable states suggest some common pathways in the formation of hypercoagulable states and may serve as potential biomarkers for the prevention and treatment of thrombotic diseases.

Elevated factor VIII levels and arterial stroke: a review of literature with a case report

Background

Cerebral arterial thromboses or ischemic strokes may be caused by cumulative or independent effects of a variety of risk factors. High factor VIII level is one of those important but less known risk factors for arterial and venous thrombosis. We hereby provide a comprehensive review of the role of high factor VIII levels as a risk factor of arterial thrombosis. Moreover, we present our views on inclusion of factor VIII testing in the etiology workup protocol of young patients with ischemic strokes and their treatment with anticoagulant therapy.

Case presentation

We illustrate a case of 32-year-old North Indian female patient with Ischemic stroke whose only identifiable risk factor was revealed to be an elevated factor VIII level. She was treated with oral anticoagulant with an uneventful follow-up of 6 months.

Conclusions

Elevated factor VIII levels have their independent and additive effects in causation and prognosis of arterial strokes. We herein discuss the mechanism of this association, the feasibility and yield of routine testing, appropriate cut-off levels, and further treatment protocol especially in young stroke patients.

Maintaining plasma quality and safety in the state of ongoing epidemic - The role of pathogen reduction

In the field of transfusion medicine, many pathogen reduction techniques (PRTs) are currently available, including those based on photochemical (PI) and photodynamic inactivation (PDI). This is particularly important in the face of emerging viral pathogens that may pose a threat to blood recipients, as in the case of the COVID-19 pandemic. However, PRTs have some limitations, primarily related to their adverse effects on coagulation factors, which should be considered before their intended use. A comprehensive search of PubMed, Wiley Online Library and Science Direct databases was conducted to identify original papers. As a result, ten studies evaluating fresh plasma and frozen-thawed plasma treated with different PI/ PDI methods and evaluating concentrations of coagulation factors and natural anticoagulants both before and after photochemical treatment were included in the review. The use of PI and PDI is associated with a significant decrease in the activity of all analysed coagulation factors, while the recovery of natural anticoagulants remains at a satisfactory level, variable for individual inactivation methods. In addition, the published evidence reviewed above does not unequivocally favour the implementation of PI/PDI either before freezing or after thawing as plasma products obtained with these two approaches seem to satisfy the existing quality criteria. Based on current evidence, if implemented responsibly and in accordance with the current guidelines, both PI and PDI can ensure satisfactory plasma quality and improve its safety.

Ovarian ectopic pregnancy: the role of complex morphopathological assay. Review and case presentation

Ovarian ectopic pregnancy (OEP) represents the rarest type of ectopic pregnancy, accounting for 1-3% of this pathology. The diagnosis of this pathology is challenging due to the non-specific clinical aspects and the ultrasound examination hampered by the lack of visible gestational sac in the presence of hematocele and hemoperitoneum. The purpose of the extended histopathological (HP) examination was to identify particular aspects of the OEP trophoblast and to highlight potential local ovarian modifications which can determine pregnancy fixation at this level. The patient presented local favorable conditions for intraovarian nidation, conditions confirmed by the HP classical examination and by the immunohistochemical evaluation. We identified, using classical Hematoxylin-Eosin, Masson's trichrome and Periodic Acid-Schiff (PAS)-Hematoxylin, necrotic hemorrhage, accentuated vascular thrombosis and high density lymphoplasmocytary infiltrate. These modifications increased local adhesivity and cell destruction through hypoperfusion. Anti-cluster of differentiation antibodies (CD34, CD38, tryptase) revealed the low number of intravillous vessels and the high number of macrophages and mastocytes involved in the local inflammatory process heighten. We identified the presence of trophoblast tissue in the ovarian structure using anti-cytokeratin AE1∕AE3 (CK AE1∕AE3)/anti-cytokeratin 7 (CK7) antibodies. The anti-alpha-smooth muscle actin (α-SMA) and anti-vimentin (VIM) antibodies displayed the density of myofibroblasts and intravillous stromal cells and with the aid of anti-progesterone receptor (PR) antibody, we identified the corpus luteum hormonal response in the OEP. The placental villosities present a blocked multiplication process at the anti-apoptotic B-cell lymphoma 2 (BCL2) protein, confirmed by the Ki67 cell proliferation and tumor protein 63 (p63) immunomarkers. Anti-neuron specific enolase (NSE), anti-calretinin and anti-inhibin A antibodies showed the particular aspects of the granulosa and internal theca cells, which may be involved in oocyte release blockage, intraluteal and extraluteal fecundation of the OEP.

INHERITED PROTEIN C AND PROTEIN S DEFICIENCY IN RENAL TRANSPLANT CANDIDATES OF SINDH PROVINCE, PAKISTAN

Background: Thrombophilia is a common risk factor for venous thromboembolism. The objective of this study was to determine prevalence of inherited protein C and protein S deficiency in renal transplant candidates of Sindh Province, Pakistan. Material & Methods: This cross-sectional study was conducted in Department of Pathology, Sindh Institute of Urology and Transplantation, Karachi, Pakistan from 16-10-2010 to 15-4-2011. 300 renal transplant candidates were selected. Candidates with acquired thrombotic disorders, women taking oral contraceptives and patients taking anti-coagulants during previous one week were excluded. Venous blood samples were collected before starting dialysis procedure or at least two days after last dialysis session. Platelet-poor plasma (PPP) was parted using plastic pipettes and protein C and protein S were processed on coagulation analyzer. Sex, age groups (<40 and ≥ 40years), presence of protein C deficiency and presence of protein S deficiency were nominal variables and analyzed by count and percentage along with population parameters. Results: 300 renal transplant candidates included 199 (66.33%) men and 101 (33.67%) women and 238 (79.33%) in age group <40 years and 62 (20.67%) cases in age group ≥40 years. Prevalence of protein C deficiency was 6.66% (20/300) and of protein S deficiency was 4% (12/300). Prevalence of PC deficiency was higher in men 5.33% than women 1.33%. Also prevalence of PS deficiency was higher in men 3.0% than women 1.0%. Prevalence of PC deficiency was higher in age group <40 years 5.67% than ≥40 years 1.0%. Also prevalence of PS deficiency was higher in age group <40 years 3.33% than ≥40 years 0.66%. Conclusion: More prolonged and follow-up studies are needed to define the true significance of deficiency of protein C and S (coagulation inhibitors) in post-transplant settings.

High factor VIII levels and arterial thrombosis: illustrative case and literature review

Thrombotic disorders are one of the most common causes of morbidity and mortality in developing and developed countries. Several well-known genetic traits underlie predisposition to venous thrombosis. In particular, high factor VIII levels are a risk factor for venous thrombosis and coronary artery disease (CAD). However, similar insight into the genetic component of arterial thrombosis predisposition has not materialized fully, despite considerable effort. The authors present an illustrative case of a 32-year-old Saudi Arabian patient with peripheral arterial thrombosis whose only identifiable risk factor were high factor VIII levels. We also provide a comprehensive review of the current state of knowledge concerning the role of high factor VIII levels in determining the risk of arterial thrombosis or ischemic heart disease (IHD). We conclude that high factor VIII levels are a risk factor for thrombosis, with a greater impact on venous than on arterial thrombosis. However, due to a lack of international consensus on methods for the laboratory testing of factor VIII levels in plasma, we would not currently recommend the measurement of factor VIII levels as part of routine thrombophilia screening.

Variceal bleeding due to idiopathic portal vein thrombosis in a 15-year-old boy

Portal vein thrombosis is an important cause of portal hypertension in the pediatric population. It is a rare and potentially fatal condition with diverse underlying pathology. A successfully managed case, without an identified etiology, is reported herein.

The relative roles of maternal survival and inter-personal violence as selection pressures on the persistence of Neanderthal hypercoagulability alleles in modern Europeans

Background: Simonti et al. reported variation in the frequency of Neanderthal alleles found in modern humans and argued that they may have provided an evolutionary advantage. One such allele is SNP rs3917862, associated with hypercoagulability. rs3917862 can be deleterious, but can also help prevent blood loss. Aim: To investigate two possible selective pressure hypotheses for rs3917862 surviving to higher frequencies: deaths from interpersonal violent trauma and childbirth. Subjects and methods: Mortality data from modern hunter-gatherers models the living conditions and causes of death of humans and Neanderthals at the point of admixture. Results: National census data indicates a positive correlation between the presence of rs3917862 and decreased maternal mortality ratios. When the maternal mortality ratio is modelled using GDP, births attended by skilled assistants and the presence of rs3917862, women are 0.1% more likely to die in childbirth in populations lacking rs3917862. Deaths due to violence show no correlation with rs3917862. Conclusion: These findings challenge the idea that Neanderthal admixture has negatively impacted the overall health of modern humans. Maternal survival may have acted as a selective pressure for the persistence of hypercoagulability alleles in modern Europeans. Understanding the role of hypercoagulability in childbirth, and the role of rs3917862, could help to reduce maternal mortality ratios.

Acute Myocardial Infarction as an Initial Presentation of Protein C and Protein S Deficiency Followed by Dilated Cardiomyopathy in a Young Male

Protein C and protein S are vitamin K dependent anti-coagulant proteins required for the inhibition of activated protein V and VIII. In an inherited thrombophilia, hypercoagulability caused by the deficiency of protein C and protein S predisposes an individual to increased risk of thromboembolism (TE) that could herald as a venous thromboemboilsm (VTE) in the leg, pulmonary embolism (PE), stroke, or Budd-Chiari syndrome. However, very rarely does inherited thrombophilia cause coronary artery thrombosis leading to the development of myocardial infarction (MI). We report a case of a young male with combined protein C and protein S deficiency who presented with acute MI, worsened ventricular systolic function, and progressive declination of ejection fraction (EF) secondary to dilated cardiomyopathy (DCM).

Direct oral anticoagulants in patients with venous thromboembolism and thrombophilia: a systematic review and meta-analysis

Essentials We investigated direct oral anticoagulant (DOAC) use in venous thromboembolism and thrombophilia. A comprehensive search identified 10 studies, 8 of which were included in a meta-analysis. DOACs were overall safe and effective in patients with venous thromboembolism and thrombophilia. Efficacy/safety of DOACs was maintained in low-risk antiphospholipid syndrome patient subgroup. SUMMARY: Background Direct oral anticoagulants (DOACs) are increasingly used in acute and long-term treatment of venous thromboembolism (VTE). However, their role in management of thrombophilia-associated VTE is controversial. Methods Through a comprehensive search on MEDLINE, Cochrane Library, and Clinicaltrials.gov, we identified 10 eligible studies, 8 of which reporting data on 1994 thrombophilia patients were included in a random-effects meta-analysis. Eligible studies were phase 2 to 3 randomized controlled trials comparing DOACs to vitamin K antagonists (VKAs) in patients with VTE, including those with thrombophilia. Results Of eight studies included in meta-analysis, four evaluated rivaroxaban, three dabigatran, and one edoxaban. No results could be obtained on apixaban use. The rates of VTE recurrence (RR, 0.70; 95% CI, 0.34-1.44; I2  = 0%) and major/clinically relevant non-major bleeding events (RR, 0.92; 95% CI, 0.62-1.36; I2  = 23%) were similar between thrombophilia patients treated with DOACs compared to VKAs. Results were comparable to findings in patients without known thrombophilia: RR, 1.02; 95% CI, 0.80-1.30; I2  = 46% for VTE recurrence and RR, 0.72; 95% CI, 0.57-0.90; I2  = 84% for major/clinically relevant non-major bleeding events. Conclusions Rates of VTE recurrence and bleeding events were both low and comparable in patients with various thrombophilias receiving either treatment, suggesting that DOACs are an appropriate treatment option in this population. Due to limited data, it is unclear whether these findings apply to specific subgroups such as high-risk antiphospholipid syndrome, uncommon thrombophilias, or the use of apixaban.

Dynamic changes of urinary proteins in a rat model of acute hypercoagulable state induced by tranexamic acid

The hypercoagulable state leads to the development of thrombotic diseases, but it is difficult to diagnose due to the lack of available biomarkers. This study aimed to investigate systematic changes of the urinary proteome in the acute hypercoagulable state. A rat model of the acute hypercoagulable state was induced by an antifibrinolytic agent tranexamic acid and urine samples were collected for proteomic analysis by liquid chromatography-tandem mass spectrometry. A total of 28 differential proteins were detected in the urinary proteome of the model rats, of which 12 had been previously considered as candidate biomarkers such as myoglobin, and 10 had been considered stable in healthy human urine. Of the 28 differentially expressed proteins 18 had counterparts in humans. Of these 18 proteins, 10 were members of the human core urinary proteome distributed in a variety of human tissues but concentrated in the urinary and digestive systems. Fumarylacetoacetase was verified as a potential marker of the acute hypercoagulable state by Western blot analysis. In conclusion, urine proteome analysis is a powerful approach to identify potential biomarkers of acute hypercoagulable state.

Urinary proteome analysis of acute hypercoagulable state in rat model induced by ε-aminocaproic acid

The hypercoagulable state occurs in a group of prothrombotic disorders associated with an increased risk for thromboembolic events, but it is difficult to diagnose due to the lack of available biomarkers. This study aimed to investigate systematic changes of urinary proteome in acute hypercoagulable state induced by certain antifibrinolytics. To reduce the effects of both genetic and environmental factors on the urinary proteome, we used a rat model of acute hypercoagulable state induced by an antifibrinolytic agent ε-aminocaproic acid, resembling human hypercoagulable state. Urine samples were collected during acute hypercoagulable state for analysis by liquid chromatography-tandem mass spectrometry (LCMS/MS). Of 65 significantly changed proteins in acute hypercoagulable state, 38 proteins had human orthologs, and 18 proteins were identified as stable in normal human urine. None of the identified proteins have been found to be clotting factors, but 4 proteins are known to be involved in the regulation of blood coagulation factors. Two proteins were verified as the markers associated with acute hypercoagulable state by Western blot analysis. In addition, four common differential urinary proteins have been found in acute hypercoagulable state induced by another antifibrinolytics tranexamic acid. These four proteins are potential biomarkers for early diagnosis of hypercoagulable state to prevent the development of thrombotic diseases.

Recurrent pulmonary embolism associated with deep venous thrombosis diagnosed as protein s deficiency owing to a novel mutation in PROS1: A case report

RATIONALE

Protein S (PS) deficiency that can be inherited or acquired is an independent risk factor for venous thromboembolism (VTE).

PATIENT CONCERNS

In this report, we present a case of recurrent pulmonary embolism (PE) and deep venous thrombosis (DVT) due to PS deficiency.

DIAGNOSES

A 32-year-old male patient with significant decrease in PS activity was detected by laboratory tests. Genetic examination of the PROS1 gene showed a transition of G to T in exon 14 (c.1792 G>T, p.E598X), which was a paternal inherited heterozygous G1792T substitution in the laminin G-type repeat domain, generating a premature stop codon at Glu598.

INTERVENTIONS

We considered that the inherited PS deficiency due to a PROS1 gene mutation may associate with recurrent VTE. The patient was suggested to have an extended anticoagulant therapy to avoid a severe VTE event.

OUTCOMES

The patient was discharged home with continued oral anticoagulants and was still seen in clinic for follow-up.

LESSONS

It is necessary for the young patient with recurrent idiopathic thrombosis to perform an inherited PS deficiency test and receive anticoagulant therapy for an extended period.

Choroidal infarction following ophthalmic artery chemotherapy

Background

Methylenetetrahydrofolate reductase (MTHFR) genetic mutations and intra-procedural inhaled nitrous oxide (N₂O) independently increase blood levels of homocysteine, a compound associated with thrombosis. Patients with MTHFR mutations who also receive N₂O during ophthalmic artery chemotherapy (OAC) for retinoblastoma may have a heightened thrombotic risk.

Case presentations

Single-center retrospective review of pediatric patients with advanced retinoblastoma who received OAC and developed choroidal infarcts. Four retinoblastoma patients with advanced intraocular disease (2 males, 2 females: 13-58 months) experienced choroidal infarcts within the one-month period after OAC, in which procedural N₂O induction was used (duration between 21 and 58 min). All 4 patients had MTHFR (chromosome 1p, position 36.22) genetic abnormalities: one was homozygous for the C677T mutation, one was C677T heterozygous, one was A1298C heterozygous, and one was heterozygous for both C677T and A1298C. In all 4 patients, indirect ophthalmoscopy and fundus photography showed marked disturbance of the retinal pigment epithelium and optical coherence tomography (OCT) confirmed thinning of the choroid. Follow-up time ranged from 15 to 46 months (median 21 months).

Conclusions

Choroidal infarction in eyes treated with OAC developed in children who were both deficient in at least one working allele of the MTHFR gene (heterozygous or homozygous) and received N₂O induction during OAC.

Role of isopeptidolysis in the process of thrombolysis

INTRODUCTION

Known thrombolytic agents either break peptide bonds in the fibrin molecule or act as plasminogen activators, which also results in peptide bond cleavage. In thrombi, fibrin molecules are known to be cross-linked by isopeptide bonds, the formation of which is mediated by factor XIIIa. In this work, we studied the dissolution of thrombi via isopeptide bond cleavage using a recombinant destabilase. Destabilase is an enzyme secreted from the medicinal leech salivary gland. This enzyme exhibits muramidase (lysozyme) activity, in addition to endo-ε-(γ-Glu)-Lys-isopeptidase activity, which is responsible for isopeptide bond cleavage.

METHODS

Venous (jugular vein) and arterial (carotid artery) thrombosis was induced in rats. Rats were intravenously injected with both recombinant destabilase produced in Escherichia coli and a commercial streptokinase preparation. After 24 h, the weight and degree of cross-linking in the thrombi were analysed. Amidolytic activity in rat blood serum was measured in order to evaluate destabilase levels in the blood.

RESULTS

Destabilase was definitively shown to cause a 47.6% and 74.6% decrease in the weight of venous and arterial thrombi, respectively. The enzyme proved to be more efficient at dissolving thrombi compared to streptokinase. The combined administration of destabilase and streptokinase has a greater effect than the injection of individual enzymes. Destabilase reduces fibrin stabilization in thrombi.

CONCLUSION

Cumulatively, we find that the medicinal leech destabilase is a more efficient thrombolytic agent for dissolving thrombi, which could help increase the overall effectiveness of conventional thrombolytic drugs.

Recurrent stroke in a patient of lung cancer without pulmonary mass: A case report

RATIONALE

Repeated occurring stroke in short intervals with hypercoagulability is unusual so in such cases the conventional vascular risk factors might not be the causes of stroke.

PATIENT CONCERNS

We have presented a case of 60-year-old male presenting with recurrent stroke due to thrombophilia.

DIAGNOSES

Lung cancer was detected by superficial lymph nodes ultrasound and further pathological examination.

INTERVENTIONS

The patient suffered a recurrent stroke and he had persistently high level of D-dimer which suggested the diagnosis of thrombophilia, thus, he was treated with low-molecular-weight heparin. Unfortunately, the treatment was not effective for the patient and he died before any other treatments could be administered.

OUTCOMES

Despite anticoagulant therapy, the patient suffered multiple episodes of stroke and ultimately died.

LESSONS

This case of recurrent stroke with coagulation disorders without evidence of cancer in imaging and blood test is rare. So in a stroke patient, we should consider malignancy or metastasis as a differential diagnosis as it may be the first manifestation of active cancer elsewhere.

Endometrial receptivity and conception outcome among women with light menstrual bleeding of unidentified etiology

OBJECTIVE

To investigate endometrial receptivity (ER), conception outcome, and other factors among women with light menstrual bleeding of unidentified etiology.

METHODS

A prospective study was undertaken at a center in China. Between January 1, 2011, and December 31, 2014, women meeting the inclusion criteria (aged 20-35 years, without any history of pregnancy, desire to conceive, follicle-stimulating hormone <10 IU on second or third day of cycle, and regular menstrual periods) were enrolled. Participants with a menstrual blood volume of 5-20 mL formed the study group; others were in the control group. ER measures were obtained by transvaginal Doppler ultrasonography. Serum estradiol and progesterone levels were measured and items of prethrombotic state were screened in mid-luteal phase. Participants were followed up for 1 year to establish conception outcome.

RESULTS

The ER (Salle) score was significantly lower in the study group (n=110) than in the control group (n=330; 9.41 ± 3.02 vs 15.67 ± 2.63, P<0.001). The natural rate of conception within 1 year was lower (60.0% [63/105] vs 72.1% [230/319], P=0.020), and the spontaneous abortion rate in early pregnancy was higher (34.4% [21/61] vs 18.1% [41/227], P=0.006) in the study group than in the control group.

CONCLUSION

Women with light menstrual bleeding of unidentified etiology had an increased prevalence of low ER and poor conception outcome.

The use of direct oral anticoagulants in inherited thrombophilia

To review the use of the direct oral anticoagulant (DOAC) agents in inherited thrombophilia based on the literature. MEDLINE, International Pharmaceutical Abstracts, and Google Scholar searches (1970-May 2016) were conducted for case reports, case series, retrospective cohorts, or clinical trials using the key words: protein C deficiency, protein S deficiency, antithrombin deficiency, activated protein C resistance, Factor V Leiden, hypercoagulable, NOACs, dabigatran, apixaban, rivaroxaban, betrixaban, edoxaban, Xa inhibitor, direct thrombin inhibitor. Results were limited to English-only articles. Clinical studies evaluating the use of DOACs for hypercoagulable states related to inherited thrombophilia were selected and evaluated. Thrombophilia, a predisposition to thrombosis, manifests predominantly as venous thromboembolism. Causes of inherited thrombophilia include antithrombin deficiency, deficiencies of proteins C and S, and Factor V Leiden mutation. Many patients with thrombophilia receive anticoagulant therapy for primary or secondary prevention of VTE, historically either warfarin or a heparin product. DOAC's have been considered as potential alternatives to traditional agents based on their pharmacologic activity. Case reports and a post-hoc analysis of a clinical trial have indicated positive results in patients with inherited thrombophilia and VTE. Positive results have been reported for the use of DOACs in inherited thrombophilia. Further robust studies are needed for definitive decision making by clinicians.

Myocardial infarction and future risk of cancer in the general population-the Tromsø Study

The association between myocardial infarction (MI) and future risk of incident cancer is scarcely investigated. Therefore, we aimed to study the risk of cancer after a first time MI in a large cohort recruited from a general population. Participants in a large population-based study without a previous history of MI or cancer (n = 28,763) were included and followed from baseline to date of cancer, death, migration or study end. Crude incidence rates (IRs) and hazard ratios (HRs) for cancer after MI were calculated. During a median follow-up of 15.7 years, 1747 subjects developed incident MI, and of these, 146 suffered from a subsequent cancer. In the multivariable-adjusted model (adjusted for age, sex, BMI, systolic blood pressure, diabetes mellitus, HDL cholesterol, smoking, physical activity and education level), MI patients had 46% (HR 1.46; 95% CI: 1.21-1.77) higher hazard ratio of cancer compared to those without MI. The increased cancer incidence was highest during the first 6 months after the MI, with a 2.2-fold higher HR (2.15; 95% CI: 1.29-3.58) compared with subjects without MI. After a 2-year period without higher incidence rate, MI patients displayed 60% (HR 1.60; 95% CI: 1.27-2.03) higher HR of future cancer more than 3 years after the event. The increased IRs were higher in women than men. Patients with MI had a higher short- and long-term incidence rate of cancer compared to subjects without MI. Our findings suggest that occult cancer and shared risk factors of MI and cancer may partly explain the association.

Utility of thrombophilia testing in patients with venous thrombo-embolism

BACKGROUND

Clinical practice of thrombophilia testing those with venous thrombo-embolism (VTE) in public hospitals may not be consistent with the international guidelines. This study aims to assess whether practice of thrombophilia testing in two public hospitals are consistent with international guidelines, and to assess whether certain groups of patients were more likely to benefit from testing.

METHODS

A retrospective audit on patients who presented to two Queensland public hospitals from August 2011 to September 2012 with VTE. Data were collected on demographics, yield of the test, and whether the result of the test changed the duration of anticoagulation. Group analysis was performed to identify patients who were more likely to yield positive results.

RESULTS

Of the 152 patients, 49% were tested for thrombophilia, of whom 31% returned a positive result. 38% of patients with provoked VTE were tested for thrombophilia, inconsistent with guideline recommendations. In 1.2% of cases there were documented changes to duration of anticoagulation with positive results. The rates of positive results were 45% in unprovoked VTE cases compared with 29% in provoked VTE cases (P=0.054). The rates of positive results were 52% in recurrent VTE cases compared with 27% in those cases with first episode of VTE (P=0.007).

CONCLUSIONS

The practice of thrombophilia testing in public hospitals was frequently inconsistent with guidelines, and did not significantly influence clinical decisions. There was higher yield of testing in patients with recurrent episodes of VTE and possibly in patients with unprovoked VTE.

Activity of coagulation factor XI in patients with spontaneous miscarriage: the presence of risk alleles

The aim of this study was to compare the activity of coagulation factor XI (FXI) between patients with spontaneous miscarriage versus control group with no history of miscarriage and thrombosis, and then we evaluated the occurrence of risk alleles in the relation to miscarriage. FXI activity was determined using a coagulometer (Sysmex, CA 1500, Japan). Single nucleotide polymorphisms (SNPs) of F11 and CYP4V2 genes were evaluated. We examined 55 patients versus 31 control subjects. We found significantly higher activity of FXI (p = 0.04) in patients versus control subjects. The occurrence of two SNPs (rs2289252 and rs2036914) of the F11 gene and SNP (rs13146272) of CYP4V2 gene was not significantly different between both groups. Increased activity of FXI may be a potential risk factor for miscarriage. High activity of FXI diagnosed in women with history of miscarriage is not probably caused by the presence of studied SNPs.

Modeling thrombin generation: plasma composition based approach

Thrombin has multiple functions in blood coagulation and its regulation is central to maintaining the balance between hemorrhage and thrombosis. Empirical and computational methods that capture thrombin generation can provide advancements to current clinical screening of the hemostatic balance at the level of the individual. In any individual, procoagulant and anticoagulant factor levels together act to generate a unique coagulation phenotype (net balance) that is reflective of the sum of its developmental, environmental, genetic, nutritional and pharmacological influences. Defining such thrombin phenotypes may provide a means to track disease progression pre-crisis. In this review we briefly describe thrombin function, methods for assessing thrombin dynamics as a phenotypic marker, computationally derived thrombin phenotypes versus determined clinical phenotypes, the boundaries of normal range thrombin generation using plasma composition based approaches and the feasibility of these approaches for predicting risk.

Hypercoagulable states: an algorithmic approach to laboratory testing and update on monitoring of direct oral anticoagulants

Hypercoagulability can result from a variety of inherited and, more commonly, acquired conditions. Testing for the underlying cause of thrombosis in a patient is complicated both by the number and variety of clinical conditions that can cause hypercoagulability as well as the many potential assay interferences. Using an algorithmic approach to hypercoagulability testing provides the ability to tailor assay selection to the clinical scenario. It also reduces the number of unnecessary tests performed, saving cost and time, and preventing potential false results. New oral anticoagulants are powerful tools for managing hypercoagulable patients; however, their use introduces new challenges in terms of test interpretation and therapeutic monitoring. The coagulation laboratory plays an essential role in testing for and treating hypercoagulable states. The input of laboratory professionals is necessary to guide appropriate testing and synthesize interpretation of results.

Risk Factors and Treatment Strategies in Patients With Retinal Vascular Occlusions

Retinal vein occlusion (RVO) and retinal artery occlusion (RAO) cause significant visual impairment. The role of thrombophilia and cardiovascular testing is uncertain, and optimal treatment strategies have not been determined. We reviewed medical records of 39 patients with RVO and RAO (23 women and 16 men). Thrombophilia and cardiovascular evaluations were performed and outcomes were reviewed. In all, 24 (61.5%) patients had at least 1 thrombophilia. Elevated factor VIII levels were found in RVO (n = 5) but not in RAO. There are no other significant differences in thrombophilias in RVO compared to those in RAO. Most patients had hypertension(41.2% RAO and 55% RVO) and hyperlipidemia (35.5% RAO and 81.8% RVO). In all, 4 women were using oral contraceptives, 2 were pregnant or postpartum. Follow-up data was available for 28 patients (13 RAO, 15 RVO). Nineteen were treated with aspirin, four with warfarin, and one with low molecular weight heparin. Eight patients reported improvement in vision at time of follow-up (5 RAO, 3 RVO). Multiple risk factors are associated with RVO and RAO, and a complete assessment should include thrombophilia and cardiovascular studies.

Reducing inpatient heritable thrombophilia testing using a clinical decision-making tool

AIMS

To evaluate the impact of a clinical decision-making tool, designed to educate physicians regarding heritable thrombophilia (HT) testing, on the volume of testing in hospitalised patients in the tertiary care setting.

METHODS

We performed a retrospective cohort study over a 6-year period (2007-2012) at a single tertiary care centre intervention site and two regional control sites. In January 2010, the intervention site instituted a policy change whereby physicians ordering HT testing on inpatients needed to complete a pre-preprinted order (PPO) form that outlined the limitations of HT testing in the hospitalised setting. Failure to complete the PPO within 24 h resulted in test cancellation. Our main outcome measure was the volume of HT testing performed at the three study sites.

RESULTS

Introduction of the PPO resulted in a 79.4% (95% CI 71.2% to 87.6%) reduction in factor V Leiden (FVL) testing at the intervention site. This decrease was significantly greater compared with those in the two control teaching hospitals over the same time periods (33.7% and 43.6%; both p<0.001). Reductions in FVL testing postintervention were observed among all ordering specialists. Similar postintervention reductions in testing volumes were observed for antithrombin (57.4%), protein C (61.9%) and protein S (62.2%) activity assays.

CONCLUSIONS

In a large tertiary care hospital, the introduction of a clinical decision-making tool significantly reduced HT testing in inpatients across clinical specialties. The impact on patient outcome should be assessed in further studies.

Models for thrombin generation and risk of disease

Computational models can offer an integrated view of blood clotting dynamics and may ultimately be instructive regarding an individual's risk of bleeding or clotting. Appropriately, developed and validated models could allow clinicians to simulate the outcomes of therapeutics and estimate risk of disease. Computational models that describe the dynamics of thrombin generation have been developed and have been used in combination with empirical studies to understand thrombin dynamics on a mechanistic basis. The translation of an individual's specific coagulation factor composition data using these models into an integrated assessment of hemostatic status may provide a route for advancing the long-term goal of individualized medicine. This review details the integrated approaches to understanding: (i) What is normal thrombin generation in individuals? (ii) What is the effect of normal range plasma composition variation on thrombin generation in pathologic states? (iii) Can disease progression or anticoagulation be followed by understanding the boundaries of normal thrombin generation defined by plasma composition? (iv) What are the controversies and limitations of current computational approaches? Progress in these areas can bring us closer to developing models that can be used to aid in identifying hemostatic risk.

Lymphocytic thrombophilic arteritis presenting as localized livedo racemosa

A 28-year-old Costa Rican woman presented with a 6-year history of an asymptomatic progressive localized livedo racemosa on her limbs. Histological examination revealed a lymphocytic vasculitis targeting the arterioles in the deep dermis. In addition, a distinct hyalinised fibrin ring was noted at the periphery of the vessel lumen. These findings were consistent with the recently described entity known as lymphocytic thrombophilic arteritis. An extensive array of investigations did not show any underlying systemic disease, and the patient has remained in good health without treatment.