Low value of inherited thrombophilia testing among patients with stroke or transient ischemic attack: A three-year retrospective study

BACKGROUND/PURPOSE

Inherited thrombophilia testing in the acute inpatient setting is controversial and expensive, and rarely changes clinical management. We evaluated ordering patterns and results of inpatient inherited thrombophilia testing for patients who presented with an isolated acute ischemic stroke or transient ischemic attack (TIA) without concurrent venous thromboembolism.

METHODS

We retrospectively analyzed patients admitted for acute ischemic stroke or TIA between January 1st, 2019 and December 31st, 2021 at Thomas Jefferson University Hospitals in Philadelphia, PA and who underwent inherited thrombophilia testing during the hospital admission. Charts were reviewed to determine stroke risk factors, test results, and clinical management.

RESULTS

Among 2108 patients admitted for acute ischemic stroke or TIA (including branch and central retinal artery occlusions) during the study period, the study included 249 patients (median age 49.0 years, 50.2% female) who underwent inpatient testing for factor V Leiden, prothrombin G20210A variant, hyperhomocysteinemia, PAI-1 elevation, and deficiencies of protein C and S and antithrombin. 42.2% of patients had at least one abnormal test, and among the 1035 tests ordered, 14.3% resulted abnormal. However, 28% of abnormal tests were borderline positive antigen or activity assays that likely represented false positives. There was no significant difference in the likelihood of a positive test among patients without stroke risk factors vs those with risk factors (47.1% vs 40.9%, P = .428), nor any significant difference between those under vs over age 50 years (45.7% vs 38.3%, P = .237). No patients with an abnormal result had their clinical management changed as a result. Charges for the tests totaled $468,588 USD.

CONCLUSIONS

Inherited thrombophilia testing in the hospital immediately following isolated acute arterial ischemic stroke or TIA was associated with high rates of likely false positive results and was expensive. Positive results did not change clinical management in a single case.

Should we screen Eastern Mediterranean COVID-19 patients for inherited thrombophilia?

The inflammatory component of Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) creates a pro-thrombotic state that necessitates a thrombophylactic strategy for hospitalized patients. Such strategies are difficult to be standardized because certain individuals can have pro-thrombotic conditions, such as inherited thrombophilia, which pre-dispose them to an additional coagulative risk. Whether outside the hospital or when admitted, patients with inherited thrombophilia need special anticoagulant and antiplatelet attention. Identifying such patients, especially in susceptible populations like the eastern Mediterranean (EM) region, will aid primary providers in risk stratification for choosing the optimal anticoagulation or antiplatelet plan.

The risk of arterial thrombosis in carriers of natural coagulation inhibitors: a prospective family cohort study

BACKGROUND

Whether the carriership of inherited antithrombin (AT), protein C (PC), and protein S (PS) deficiency increases the risk of arterial thromboembolic events (ATE) is controversial. This information has the potential to inform the management of family members of probands with inherited deficiency of natural anticoagulants.

PATIENTS/METHODS

We conducted a large prospective family cohort study in 640 subjects (of whom 341 carriers and 299 non-carriers) belonging to 86 families with inherited deficiency of AT, PC, or PS.

RESULTS

A total of 4240 and 3810 patient-years were available for carriers and non-carriers, respectively. Risk factors for atherosclerosis were similarly distributed in the two groups. Of the 26 ATE that were recorded, 19 occurred in carriers (5.6%), as compared to 7 in non-carriers (2.3%) [p = 0.07]. After adjusting for confounders, the hazard ratio (HR) for ATE was 4.9 (95% CI 1.5-16.3) in carriers as compared to non-carriers.

CONCLUSIONS

Among family members of probands with an inherited deficiency of natural anticoagulants, carriers exhibit a risk of ATE that is almost five times higher than in non-carriers.

Evaluation and Management of Coagulopathies and Thrombophilias in Pediatric Patients

The diagnosis of coagulopathy or thrombophilia in pediatric patients can be challenging. Congenital coagulopathies often present in the pediatric period and require appropriate work-up for diagnosis and ongoing management. Acquired coagulopathies of childhood are frequently encountered in hospitalized children and warrant appropriate coagulation testing for goal-directed therapy. The incidence of thrombosis is increasing in pediatric patients. After identifying the presence of thrombus, acute management includes initiating therapeutic anticoagulation. Choice of anticoagulant depends on patient's clinical status, along with availability of the anticoagulant. Thrombophilia evaluation is performed when children present with spontaneous thrombosis. Thrombophilia tests are inaccurate during acute illness.

ST-elevation myocardial infarction, pulmonary embolism, and cerebral ischemic stroke in a patient with critically low levels of natural anticoagulants

This clinical case report describes the simultaneous development of an acute myocardial infarction, stroke, and a massive pulmonary thromboembolism in a 44-year-old patient - a carrier of the thrombophilia gene polymorphisms: MTHFR C677T, А1298C, PAI-1 4G/5G, ITGA2 C807T. Multifocal thrombosis was probably due to the initial congenital deficiency of anticoagulants, accompanied by a decrease in antithrombin III and protein C, against the background of their critical consumption in cascade thrombosis, in combination with the carrier of polymorphisms of moderate and low thrombogenic risk. This case is unique in that there is usually a tendency toward clinical thrombosis when the level of antithrombin III is less than 70%. Such patients develop thrombosis at a younger age, and by the age of 35-40 years usually have a verified diagnosis of extremely high-risk hereditary thrombophilia. In this case, multifocal thrombosis was accompanied by critically low values of anticoagulants: antithrombin III - 3.4%, and protein C - 36.8%. The patient had suffered from epilepsy since childhood and took anticonvulsant drugs that increase the deficit of active folic acid and can lead to hyperhomocysteinemia, which in this case, against the background of an innate decrease in the activity of methyltetrahydrofolate reductase, could have aggravated the situation. <Learning objective: To focus on the possibility of the manifestation of multifocal thrombosis in congenital thrombophilia in adulthood against the background of critically low values of anticoagulants - antithrombin III and protein C.>.

Perinatal complications related to inherited thrombophilia: review of evidence in different regions of the world

The term thrombophilia describes disorders associated with an increased predisposition of developing venous thromboembolism (VTE). It may be acquired, like in those with antiphospholipid syndrome or inherited. The aim of this review was to compare the complications and outcomes of pregnancies in women with inherited thrombophilia between different populations, including the population of our country where the results of the research are scarce. The review of literature included all papers indexed on PubMed and Medline in the last 20 years, with different study design, including other reviews of literature, systematic reviews with meta-analysis and several case-control studies and population-based cohort studies. We aimed to cover as many geographic regions as possible with the aim to show the differences in the different parts of the world and including our country. Our analysis showed that types of thrombophilia differ in different geographic regions. Also, the differences exist between one particular type of thrombophilia in different regions. Nevertheless, no matter what the differences are between prevalence, all authors investigated the association between inherited thrombophilia and poor pregnancy outcome and managed to find some kind of association. The case with our own country is similar. Although we lack in studies with this issue and the design of published studies is not powerful enough, we may conclude that in our samples, women with thrombophilia are in potential risk of several poor pregnancy outcomes. Further and better analyses are necessary to prove this hypothesis not only on the level of study sample but also on general population. Given the fact that thrombophilia certainly affects the pregnancy and its outcome, the urge to perform screening tests in every woman suspected to have this kind of disorder and with respect to differences that exist in different world regions is inevitable.

Evaluation of Factor V Leiden and prothrombin G20210A mutations in Sudanese women with severe preeclampsia

BACKGROUND

Preeclampsia (PE) is a common pregnancy complication and one of the main causes of maternal and fetal morbidity and mortality, worldwide. While the pathogenesis of PE is unclear, it has been suggested that hypercoagulability due to Factor V Leiden (FVL) and prothrombin gene mutation (FII G20210A) play a role in its progression.

PURPOSE

This study aimed to determine if there is an association between FVL and FII G20210A mutations and severe PE.

PATIENTS AND METHODS

This case-control study enrolled 50 women with severe PE and 50 healthy pregnant women as the control, at Khartoum North Teaching Hospital, in Khartoum State, Sudan, from January 2017 to June 2017. The presence of point mutations in FVL and FII G20210A were determined for each of the participants. Deoxyribonucleic acid (DNA) was extracted, and then an allele-specific polymerase chain reaction (PCR) was used to detect the point mutations in FVL and FII G20210A.

RESULTS

The results revealed a significant difference between the subjects in the severe PE group and the control group for the means of parity, gestational age/ week and hemoglobin concentration (P < 0.05). No statistically significant body mass index (BMI) differences were found between the groups (P > 0.05). Women with severe PE were found to have a significant difference in FVL (16%; P value = 0.0058; OR: 20.20; 95%CI: 1.132-360.5) and FII G20210A (14%; P value = 0.0125; OR: 17.41; 95%CI: 0.9659-314.0) in comparison to the women in the control group (0%).

CONCLUSION

Our findings intensely indicate that there is a statistically proven significant association between FVL, FII G20210A mutations and the development of severe preeclampsia in Sudanese pregnant women.

Risk factors and role of low molecular weight heparin in obstetric complications among women with inherited thrombophilia - a cohort study

Introduction

Although there is a vast literature regarding the association between inherited thrombophilia, obstetric complications and the effect of low molecular weight heparin (LMWH), these are controversial and we have not found publications related to additional risk factors other than thrombophilia.

Our objectives were to assess the prevalence of miscarriage, placenta-mediated pregnancy complications and fetal loss in pregnant women with IT, establishing associated risk factors and the effect of LMWH.

Materials and methods

A retrospective cohort of pregnant women with IT was formed. Risk factors considered were: high-risk IT, age ≥35 years, body mass index ≥25 and ≥30, assisted reproductive technology, antiphospholipid antibodies, autoimmune disease, first-degree family history of obstetric complications and personal history of venous or arterial thromboembolic disease, the outcomes being M, FL and PMPC.

Results and conclusions

Data from 250 pregnancies in 88 women were obtained.

There were 112 (45%) Ms, 13 (5.2%) FLs and 25 (10%) PMPCs.

High-risk IT was associated with FL (OR = 4.96; 95% CI, 1.42–17.3). Antiphospholipid antibodies and family history of obstetric complications were associated with PMPC (OR = 7.12; 95% CI, 1.89–26.74, OR = 3.88; 95% CI, 1.18–12.78, respectively). The LMWH presented a benefit in the combined outcome (any obstetric complication, OR = 0.25; 95% CI, 0.12–0.54) and M (OR = 0.41; 95% CI, 0.20–0.82).

We conclude that obstetric complications are common in women with IT. Antiphospholipid antibodies, family history of obstetric complications and high-risk IT might be additional risk factors. The LMWH has an apparent protective effect against obstetric complications, which is consistent with some previous studies.

Prevalence of antiphospholipid (aPL) antibodies among patients with chronic thromboembolic pulmonary hypertension: a systematic review and meta-analysis

How thrombophilia may contribute to the development of chronic thromboembolic pulmonary hypertension (CTEPH) is unknown. We searched on PubMed and EMBASE (until 15 April 2018), studies on CTEPH reporting data on inherited or acquired thrombophilia. Starting from 367 articles mentioning the search terms, 347 were excluded mainly as duplicate articles or articles not in English. After reading the full text of remaining articles, ten were excluded for being reviews, editorials, letters or case reports, and two were further removed from the analysis because of the potential selection bias. All the eight considered studies provided the proportion of patients positive for antiphospholipid (aPL) antibodies. The crude rate of aPL in CTPEH patients is 11.8% (95% CI 10.09-13.8%). The meta-analysis considering the weighted mean proportion and 95% confidence intervals (CIs) yields a rate of aPL antibody-positive profile of 12.06% (95% CI 8.12-16.65%) among the patients with CTEPH in the random effects model (I² 76.33%; 95% CI 52.75-88.14%, p = 0.0001). The sensibility analysis confirms the result. No predictors of heterogeneity are found in a meta-regression analysis. Our results suggest that aPL antibodies are frequently associated with CTEPH underlining the need to test for aPL antibodies in young patients with "idiopathic" and "provoked" PE caused by mild provoking risk factors.

Inherited thrombophilia in unprovoked venous thromboembolism: Is non 'O' blood group an additional culprit in Indian patients?

BACKGROUND

Venous thromboembolism (VTE) is a known situation of considerable mortality and morbidity and occurs due to the convergence of multiple acquired and genetic risk factors.

METHODS

In this study, we have comprehensively analyzed the effect of ABO blood groups and inherited thrombophilia factors [Protein C (PC), Protein S (PS), Antithrombin III (AT III), Activated Protein C Resistance (APCR) and Homocysteine (Hcy)] on 150 unprovoked VTE patients, comparing with normal healthy controls. ABO phenotyping was done using gel cards and thrombophilia workup done using standard kits on coagulation autoanalyzer.

RESULTS

Non O blood group was significantly more frequent among cases than controls (77.3% vs. 62.7%) and had higher odds of VTE (OR = 2.03, 95%CI: 1.22-3.37).Positivity for at least one marker of thrombophilia was more in cases (40%) than controls (16%), and led to significantly higher odds (OR = 3.5, 95%CI: 2.03-6.04) of VTE. Deficiency of PS was the commonest thrombophilia abnormality.Combination of non O group with positivity for thrombophilia markers was also more among cases (OR = 5.67, 95%CI: 2.76-11.65). Highest odds of VTE in cases were associated with non O group in combination with increased Homocystein (OR = 10.8, 95%CI: 2.27-51.5).

CONCLUSION

The study results show non O blood group and positivity for factors of inherited thrombophilia in cases impart higher odds of VTE individually. Also combination of both non O blood group and positivity for factors of inherited thrombophilia in cases further increases the odds of VTE. This awareness could assist physicians in identifying those at higher risk of VTE and tailor-made the thromboprophylaxis accordingly.

Management of inherited thrombophilia in pregnancy

Adverse pregnancy outcomes, such as pregnancy loss and pre-eclampsia, are associated with thrombotic mechanisms and thrombophilia. Antithrombotic interventions, particularly low-molecular-weight heparin, have been investigated in women identified by previous pregnancy outcome; however, the results have been inconsistent. This may reflect heterogeneity of both the study groups and the disease processes resulting in inadequate stratification to guide antithrombotic interventions. Furthermore, the variation in gestation at initiation of low-molecular-weight heparin treatment might be important. Despite limited evidence of efficacy, low-molecular-weight heparin is often used in an attempt to prevent these complications, owing to the lack of other effective treatments and its perceived safety in pregnancy. Research is required to better understand the disease processes, identify possible biomarkers and thereby more homogeneous groups for targeted treatment.

Idiopathic thrombosis

Idiopathic thrombosis involves a group of inherited thrombophilia predisposed to severe thrombosis of early onset and associated with an adverse outcome due to recurrence, and therefore, requires long-term anticoagulation therapy. The causative factors of a predisposition to thrombosis include immobility, dehydration, infection, surgery, injury, cancer, pregnancy, and estrogen use. The inherited deficiencies of antithrombin (AT), protein C (PC), and protein S (PS) are specified as "Specific Pediatric Chronic Diseases." However, medical expense assistance for patients terminates when they reach the age of 20 years. On April 1^st 2017, "Idiopathic Thrombosis due to Inherited Thrombophilia," consisting of inherited AT, PC, and PS deficiencies, was specified as an "Intractable Disease," and aid for medical expenses became available. Accordingly, progress in the research and practice of idiopathic thrombosis is expected in future to improve the medical care system and to construct a database via clinical surveys.

Inherited thrombophilia and reproductive disorders

Apart from its established role in the pathogenesis of venous thromboembolism (VTE), inherited thrombophilia has been proposed as a possible cause of pregnancy loss and vascular gestational complications. There is a lot of controversy in the literature on the relationship between inherited prothrombotic defects and these obstetric complications. This is a review of the literature on inherited thrombophilia and reproductive disorders. Factor V Leiden, prothrombin G20210A mutation, and protein S deficiency seem to be associated with late and recurrent early pregnancy loss, while their impact on other pregnancy complications is conflicting. No definite association has been established between protein C and antithrombin deficiency and adverse pregnancy outcome, primarily due to their low prevalence. Screening is suggested only for women with early recurrent loss or late pregnancy loss. Anticoagulant treatment during pregnancy should be considered for women with complications who were tested positive for thrombophilia.

Possible incorrect genotyping of heterozygous factor V Leiden and Prothrombin 20210 gene mutations by the GeneXpert assay

BACKGROUND

The GeneXpert analyzer is a hands-off system for the detection of Factor V Leiden and of Prothrombin G20210A (GPRO) gene thrombophilic mutations. Although the system is efficient and easy to use, we report the rare possibility of incorrect genotyping.

METHODS

1648 samples were evaluated using the GeneXpert HemosIL Factor II and Factor V assay: 1319 were freshly analyzed while 329 were frozen, thawed and diluted with saline prior to analysis to avoid clogging of the instrument syringe.

RESULTS

Two samples, both heterozygous, one for the factor V Leiden and the other for the GPRO gene, were incorrectly genotyped as homozygous for the relative mutation. Inspection of the Ct values and amplification curves and genotyping with PCR revealed the correct genotype as heterozygous for factor V Leiden and GPRO mutation.

DISCUSSION

The GeneXpert HemosIL Factor II and Factor V assay is an automated, fast genotyping assay requiring almost no sample manipulation, advantageous characteristics if compared with other PCR-based methods. However, an inattentive use of it can generate incorrect diagnosis. A careful handling of the sample, in particular correct dilution of frozen/thawed samples before analysis, and the inspection of the amplification curves and Ct values are required to avoid artifacts.

Polymorphisms in thrombophilic genes are associated with deep venous thromboembolism in an Iranian population

It has been revealed that the inherited thrombophilia increases the risk of thrombosis in the venous system. To study the association of factor V G1691A, factor V HR2 (4070A/G), prothrombin G20210A, and PAI-1 (- 675 I/D, 5G/4G) polymorphisms with deep venous thromboembolism (DVT), these polymorphisms were investigated. A total of 193 patients who presented clinical symptoms of deep venous thromboembolism including 103 men and 90 women, and 500 healthy individuals without both personal and family histories of thromboembolic disorders including 275 men and 225 women were recruited into the study. Genotyping was carried out using the amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) technique. Our results showed that the genotype distribution for FV (G1691A and A4070G) and PAI-1 4G/5G polymorphisms in DVT patients were significantly higher than healthy control (P < 0.05). Also, the mutant allele frequencies for all studied polymorphisms differed significantly between the case and control groups (P < 0.05). We concluded that the prevalence of FV (G1691A and A4070G) and PAI-1 4G/5G polymorphisms increased the risk of DVT occurrence in subjects. These findings provide additional evidence to support the hypothesis that thrombophilic gene polymorphisms are involved in vascular thromboembolism.

A review of the Guidelines from Scientific Societies and Working Groups

The clinical penetrance of venous thromboembolism (VTE) susceptibility genes is variable, being lower in heterozygous carriers of factor V Leiden and prothrombin 20210A (mild thrombophilia), and higher in the rare carriers of deficiencies of antithrombin, protein C or S, and those with multiple or homozygous abnormalities (high-risk thrombophilia). The absolute risk of VTE is low, and the utility of laboratory investigation for inherited thrombophilia in patients with VTE and their asymptomatic relatives has been largely debated, leading to the production of several Guidelines from Scientific Societies and Working Groups. The risk for VTE largely depends on the family history of VTE. Therefore, indiscriminate search for carriers is of no utility, and targeted screening is potentially more fruitful. In patients with VTE inherited thrombophilia is not scored as a determinant of recurrence, playing a minor role in the decision of prolonging anticoagulation; indeed, a few guidelines consider testing worthwhile to identify carriers of high-risk thrombophilia, particularly those with a family history of VTE. The identification of the asymptomatic carrier relatives of the probands with VTE and thrombophilia could reduce cases of provoked VTE, offering them primary antithrombotic prophylaxis during risk situations. In most guidelines, this is considered justified only for relatives of probands with a deficiency of natural anticoagulants or multiple abnormalities. Counselling the asymptomatic female relatives of individuals with VTE and/or thrombophilia before pregnancy or the prescription of hormonal treatments should be administered with consideration of the risk driven by the type of thrombophilia and the family history of VTE.