Impact of Thrombophilic Genetic Factors on Pulmonary Embolism: Early Onset and Recurrent Incidences

Clinical profile and outcome of isolated pulmonary embolism: a systematic review and meta-analysis

Background

Isolated pulmonary embolism (PE) appears to be associated with a specific clinical profile and sequelae compared to deep vein thrombosis (DVT)-associated PE. The objective of this study was to identify clinical characteristics that discriminate both phenotypes, and to characterize their differences in clinical outcome.

Methods

We performed a systematic review and meta-analysis of studies comparing PE phenotypes. A systematic search of the electronic databases PubMed and CENTRAL was conducted, from inception until January 27, 2023. Exclusion criteria were irrelevant content, inability to retrieve the article, language other than English or German, the article comprising a review or case study/series, and inappropriate study design. Data on risk factors, clinical characteristics and clinical endpoints were pooled using random-effects meta-analyses.

Findings

Fifty studies with 435,768 PE patients were included. In low risk of bias studies, 30% [95% CI 19-42%, I ² = 97%] of PE were isolated. The Factor V Leiden [OR: 0.47, 95% CI 0.37-0.58, I ² = 0%] and prothrombin G20210A mutations [OR: 0.55, 95% CI 0.41-0.75, I ² = 0%] were significantly less prevalent among patients with isolated PE. Female sex [OR: 1.30, 95% CI 1.17-1.45, I ² = 79%], recent invasive surgery [OR: 1.31, 95% CI 1.23-1.41, I ² = 65%], a history of myocardial infarction [OR: 2.07, 95% CI 1.85-2.32, I ² = 0%], left-sided heart failure [OR: 1.70, 95% CI 1.37-2.10, I ² = 76%], peripheral artery disease [OR: 1.36, 95% CI 1.31-1.42, I ² = 0%] and diabetes mellitus [OR: 1.23, 95% CI 1.21-1.25, I ² = 0%] were significantly more frequently represented among isolated PE patients. In a synthesis of clinical outcome data, the risk of recurrent VTE in isolated PE was half that of DVT-associated PE [RR: 0.55, 95% CI 0.44-0.69, I ² = 0%], while the risk of arterial thrombosis was nearly 3-fold higher [RR: 2.93, 95% CI 1.43-6.02, I ² = 0%].

Interpretation

Our findings suggest that isolated PE appears to be a specific entity that may signal a long-term risk of arterial thrombosis. Randomised controlled trials are necessary to establish whether alternative treatment regimens are beneficial for this patient subgroup.

Funding

None.

Traditional risk factors and combined genetic markers of recurrent ischemic stroke in adults

BACKGROUND

The involvement of traditional risk factors and combined genetic markers of recurrent arterial ischemic stroke (AIS) in adults remains unclear.

OBJECTIVE

This study aims to determine significant clinical and genetic factors of AIS recurrence, and to investigate the combined effect of genotypes on the occurrence of a second cerebral ischemic attack.

METHODS

We investigated a cohort study of AIS patients (18-50 years old) followed in the neurology department over 5 years. Traditional and genetic risk factors were carried through a multivariable logistic regression model. We used a Cox proportional hazard model for identifying predictors of recurrence.

RESULTS

Two hundred and seventy patients were enrolled in our study. The risk of AIS recurrence was 36.2% within 5 years. The potential risk of recurrence of AIS increased with traditional and genetic risk factors such as hypertension, diabetes mellitus, heart failure, and family history of cerebrovascular diseases. This risk increased with increasing number of genetic factors. The hazard ratio (HR) was 0.66 (95% confidence interval [CI] 0.97-2.67) for the subject with one genetic factor, 1.61 (95% CI 0.97-2.25) for combined methylenetetrahydrofolate reductase (MTHFR) polymorphisms, and 2.57 (95% CI 1.32-4.99) for combined factor V Leiden (FVL) and MTHFR polymorphisms (677 or 1298). The HR for the three polymorphisms combined was 6.04 (95% CI 2.40-15.16).

CONCLUSIONS

Our findings suggest that cumulative effect of both traditional and common genetic risk factors was associated with recurrence of ischemic stroke. We demonstrated for the first time that a combined genotype FVL/MTHFR profile increase the risk of a second cerebral ischemic attack.

Fibulins: a new biomarker for pulmonary thromboembolism?

OBJECTIVES

Fibulin-1, -2, -4, and -5 have important role in several vascular diseases. We aimed to investigate if fibulin-4 and -5 can be used as a biomarker for pulmonary thromboembolism (PTE).

METHODS

This is a prospective case control study. Thirthy patients diagnosed with PTE and 31 in the control group. Data on demographic characteristics, length of hospital stay, blood cell counts, troponin and BNP levels, arterial blood gases, radiological reports, indication for thromboembolitic treatment, intensive care unit (ICU) requirement, and loss of life were recorded for the patients group. Serum Fibulin-4 and Fibulin-5 levels were measured.

RESULTS

Fibulin 4 levels correlated positively with female gender (p < .01, r = 0.433). Positive results were found in 14 (46.7%) patients for PESI.0.1; in 7 (23.3%) patients for D-dimer; in 7 (23.3%) patients for troponin-I; in 7(23.3%) patients for BNP. Median values for Fibulin 4 level were significantly higher in patients positive for BNP. Fibulin-5 level was found to be correlated with the presence of embolism (p = .041, r = 0.263).

CONCLUSIONS

Fibulin-4 and -5 have been shown to be relevant to cardiovascular biology and diseases. Experimental studies and observations in humans show that they may play a role in several cardiovascular diseases particularly pulmonary embolism.

Association between fibrinogen receptor (Glycoprotein IIb) polymorphism and the risk of venous thromboembolism: a systematic review

Background

The fibrinogen receptor is an integrin on the platelet surface and is shaped from two types of glycoprotein (GP) subunits, GPIIb and GPIIIa. Membrane glycoprotein IIb/IIIa plays an important role in platelet function. The gene encoding the glycoprotein IIIa shows a common polymorphism, PLA2 that increases the binding of the receptor to fibrinogen and enhances the platelet aggregation. The clinical impact of PLA2 polymorphism has been studied in some diseases, but the definition of its exact role on venous thromboembolism complications has been challenging. The present systematic review aimed to clarify the association of PLA2 polymorphism and venous thromboembolism.

Main text

In this study, Electronic databases including PubMed, Embase, Scopus, Web of Science, and Cochrane Library were searched. All the assessed studies focused on the relationship between PLA2 polymorphism and venous thromboembolism. Five studies were eligible for systematic review. One study revealed a significant correlation between PLA2 polymorphism and venous thromboembolism. PLA2 polymorphism was associated with deep vein thrombosis in one study and pulmonary thromboembolism in another one.

Conclusion

The published data supported the hypothesis that having the PLA2 polymorphism of GPIIIa may be a risk factor for venous thromboembolism, but the association cannot be concluded; it needs more clinical investigation.

Association of folate metabolism gene polymorphisms and haplotype combination with pulmonary embolism risk in Chinese Han population

In this study, we aimed to investigate the association of four single nucleotide polymorphisms (SNPs) (MTHFR 677 C > T, MTHFR 1298 A > C, MTR 2756 A > G and MTRR 66 A > G), gene-gene interaction and haplotype combination with pulmonary embolism (PE) risk based on Chinese Han population. Logistic regression was performed to investigate association between four SNPs within folate metabolism gene and PE risk, and GMDR model was used to investigate the additional gene-gene interactions among the four SNPs. Logistic analysis showed that rs1801133 and rs1801131 in MTHFR gene were associated with increased PE risk in both additive and dominant models. The carriers with homozygous mutant of rs1801133 polymorphism and homozygous of rs1801131 were associated with increased PE risk, and ORs (95% CI) were 1.71(1.24-2.21) and 1.58 (1.24-2.01), respectively. We also found a significant gene-gene interaction between rs1801133 and rs1801131 on PE. Overall, the cross-validation consistency of this two-locus model was 10/10, and the testing accuracy was 60.72%, after adjusting for covariates. Haplotype containing the rs1801133- T and rs1801131- C alleles were associated with a statistically increased PE risk, OR (95% CI) = 2.68 (1.28-4.13), P < 0.001. We found that rs1801133 and rs1801131 within MTHFR gene, their interaction, and haplotype containing the rs1801133- T and rs1801131- C alleles were all associated with PE risk.

The importance of MTHFR C677T/A1298C combined polymorphisms in pulmonary embolism in Turkish population

BACKGROUND AND OBJECTIVE

Pulmonary embolism (PE) is an important cardiovascular emergency with high mortality. There are still problems related to the diagnosis of PE and genetic research may play a key role on diagnosis as well as determining risk stratification. In the present study, the aim was to evaluate MTHFR C677T and A1298C polymorphisms that play a role on folate metabolism in PE patients.

MATERIALS AND METHODS

A total of 118 PE patients and 126 controls were enrolled in the current study. Genomic DNA was isolated and genotyped using polymerase chain reaction (PCR) analyses for the MTHFR C677T and A1298C polymorphisms.

RESULTS

There was no association between clinical and demographic characteristics of PE patients and both MTHFR C677T and A1298C polymorphisms. Allele frequencies showed a significant difference between patients and controls. T allele frequency was significantly higher in the patients' group than the control group. There was an association between PE and combined MTHFR C677T and A1298C polymorphisms.

CONCLUSION

We found an association between MTHFR C677T/A1298C combined mutations and PE in the Turkish population. Future genetic studies investigating combined mutations could be very helpful to identify risk population in PE.

A preliminary study of inherited thrombophilic risk factors in different clinical manifestations of venous thromboembolism in central Iran

Background & objectives:

Inherited thrombophilia is known to be an important risk factor for developing venous thromboembolism. Whether such abnormalities may impact the development of deep vein thrombosis (DVT) and pulmonary embolism (PE) differently is not well defined. This preliminary study was undertaken to compare thrombophilic polymorphism in patients with DVT and PE.

Methods:

A total of 35 DVT, 23 DVT/PE, and 37 PE patients admitted to the Hajar Hospital, Shahrekord, Iran, between October 2009 and February 2011 were included in the study and 306 healthy volunteers matched by age and sex from the same geographical area with no history of venous or arterial diseases were included as control group. Factor V Leiden (FV 1691G/A, rs6025), prothrombin (FII 20210G/A), methylene tetrahydrofulate reductase (MTHFR 677C/T, rs1801133), and PLA2 polymorphisms of platelet glycoprotein IIb/IIIa (GpIIIa 1565T/C, rs5918) were investigated by polymerase chain reaction-restriction fragment length polymorphism.

Results:

The number of patients with the investigated polymorphisms and homozygous carriers was significantly different among the groups (P<0.05). No significant difference was observed in the presence of FV 1691G/A and FII 20210G/A between any of the patients groups and the control group. GpIIIa 1565T/C and homozygous MTHFR 677C/T polymorphisms were higher in DVT patients compared with the control group (OR=6.65, 95% CI=3.09-14.30 and OR=4.08, 95% CI=1.35-12.38, respectively).

Interpretation & conclusions:

As none of the investigated polymorphisms were associated with PE, other thrombophilia polymorphisms may have a role in the pathogenesis of PE in these patients and should be investigated. Because of different prognostic risk factors among different types of patients, the treatment approach could be different.

Testosterone, thrombophilia, thrombosis

We screened previously undiagnosed thrombophilia (V Leiden-prothrombin mutations, Factors VIII and XI, homocysteine, and antiphospholipid antibody [APL] syndrome) in 15 men and 2 women with venous thromboembolism (VTE) or osteonecrosis 7 months (median) after starting testosterone therapy (TT), gel (30-50 mg/d), intramuscular (100-400 mg/wk), or human chorionic gonadotropin (HCG) (6000 IU/wk). Thrombophilia was studied in 2 healthy control groups without thrombosis (97 normal controls, 31 subjects on TT) and in a third control group (n = 22) with VTE, not on TT. Of the 17 cases, 76% had ≥1 thrombophilia vs 19% of 97 normal controls (P < 0.0001), vs 29% of 31 TT controls (P = 0.002). Cases differed from normal controls by Factor V Leiden (12% vs 0%, P = 0.021), by high Factor VIII (>150%) (24% vs 7%, P = 0.058), by high homocysteine (29% vs 5%, P = 0.007), and from both normal and TT controls for APL syndrome (18% vs 2%, P = 0.023, vs 0%, P = 0.04). Despite adequate anticoagulation with TT continued after the first deep venous thrombosis-pulmonary embolus (DVT-PE), 1 man sustained 3 DVT-PEs 5, 8, and 11 months later and a second man had 2 DVT-PEs 1 and 2 months later. Of the 10 cases with serum T measured on TT, 6 (60%) had supranormal T (>800 ng/dL) and of 9 with estradiol measured on TT, 7 (78%) had supranormal levels (>42.6 pg/mL). TT interacts with thrombophilia leading to thrombosis. TT continuation in thrombophilic men is contraindicated because of recurrent thrombi despite anticoagulation. Screening for thrombophilia before starting TT should identify subjects at high risk for VTE with an adverse the risk to benefit ratio for TT.

Risk of venous thromboembolism associated with single and combined effects of Factor V Leiden, Prothrombin 20210A and Methylenetethraydrofolate reductase C677T: a meta-analysis involving over 11,000 cases and 21,000 controls

Genetic and environmental factors interact in determining the risk of venous thromboembolism (VTE). The risk associated with the polymorphic variants G1691A of factor V (Factor V Leiden, FVL), G20210A of prothrombin (PT20210A) and C677T of methylentetrahydrofolate reductase (C677T MTHFR) genes has been investigated in many studies. We performed a pooled analysis of case-control and cohort studies investigating in adults the association between each variant and VTE, published on Pubmed, Embase or Google through January 2010. Authors of eligible papers, were invited to provide all available individual data for the pooling. The Odds Ratio (OR) for first VTE associated with each variant, individually and combined with the others, were calculated with a random effect model, in heterozygotes and homozygotes (dominant model for FVL and PT20210A; recessive for C677T MTHFR). We analysed 31 databases, including 11,239 cases and 21,521 controls. No significant association with VTE was found for homozygous C677T MTHFR (OR: 1.38; 95 % confidence intervals [CI]: 0.98-1.93), whereas the risk was increased in carriers of either heterozygous FVL or PT20210 (OR = 4.22; 95 % CI: 3.35-5.32; and OR = 2.79;95 % CI: 2.25-3.46, respectively), in double heterozygotes (OR = 3.42; 95 %CI 1.64-7.13), and in homozygous FVL or PT20210A (OR = 11.45; 95 %CI: 6.79-19.29; and OR: 6.74 (CI 95 % 2.19-20.72), respectively). The stratified analyses showed a stronger effect of FVL on individuals ≤ 45 years (p value for interaction = 0.036) and of PT20210A in women using oral contraceptives (p-value for interaction = 0.045). In this large pooled analysis, inclusive of large studies like MEGA, no effect was found for C677T MTHFR on VTE; FVL and PT20210A were confirmed to be moderate risk factors. Notably, double carriers of the two genetic variants produced an impact on VTE risk significantly increased but weaker than previously thought.

Cause of deep venous thrombosis and pulmonary embolism in young patients from India as compared with other ethnic groups

Venous thromboembolism (VTE), which consists of deep vein thrombosis (DVT) and pulmonary embolism, is a potentially fatal disease. The existing Asian literature has shown a wide variation in the prevalence of VTE, with very limited data from India. In the present study, the risk factors for VTE in Indian patients were compared with Caucasians and Blacks. We used data prospectively collected from total of 1396 Indian patients (716 males, 680 females) enrolled over a decade and compared with White (n = 2002) and Black (n = 395) patients objectively diagnosed with VTE. When compared with females, males had significantly higher episodes of pulmonary embolism and VTE (P = 0.0001). Amongst the known thrombophilia markers, only homocysteine was found to be significantly higher in males as compared with females (P = 0.006). Males had a higher proportion of rheumatic heart disease (RHD) and ischaemic heart disease (IHD) as compared with females. The prevalence of DVT amongst Indians was significantly higher as compared with Whites and Blacks. However, the rate of pulmonary embolism and VTE was lower in Indians as compared with both the races. Amongst the baseline characteristics identified as risk factors for VTE, Indians had a higher prevalence of infection as compared to both Whites and Blacks, but lower HIV infection as compared to Blacks. As compared to Whites, Indians had lower prevalence of idiopathic VTE (but similar to blacks) and had higher prevalence of idiopathic pulmonary embolism (P < 0.0001). This can be explained by different inherited and environment risk factors between these three populations.

Prevalence of 1691G>A FV mutation in Poland compared with that in other Central, Eastern and South-Eastern European countries

The 1691G>A FV variant has been described as a common genetic risk factor in venous thromboembolism. The purpose of this study was to provide a further frequency value for 1691G>A FV in Poland and to collate summary data from Central (Poland, Czech, Slovakia), Eastern (Russia, Belarus, Ukraine) and South-Eastern (Slovenia, Croatia, Bosnia and Herzegovina, Serbia, Montenegro, Macedonia, Bulgaria) European countries. For this purpose in 2007 the 1691G>A FV variant was analyzed by polymerase chain reaction-restriction fragment length polymorphism from DNA collected in 2005-2006. We studied 650 subjects: 400 newborns and 250 older individuals (mean age 46.1 y) from Poland and compared results with reports from other countries, as well as with the frequency trend of 845G>A HFE across South-Eastern European countries using centroid cities. From our 1691G>A FV study we identified 626 GG homozygotes, 23 GA heterozygotes, and 1 AA homozygote (n = 650), giving an A allele frequency of 1.9%, and a summed frequency value for Poland of 2.0% (n = 1588); the frequency in Central European countries was 3.9% (n = 4559), mostly due to the high value in the Czech Republic: 5.1% (n = 2819); the South-Eastern European countries had 2.5% (n = 2410). Among the Eastern European countries the 1691G>A FV allele frequency was 1.9% (n=791), between the South-Eastern and Eastern European countries there was no significant difference (p=0.17). We confirm that the 1691G>A FV allele frequency in Poland, as well as other countries compared, is significantly lower than that in Czech.

Genetic Mutations in Turkish Population With Pulmonary Embolism and Deep Venous Thrombosis

Venous thromboembolism (VTE) is a universal health hazard. Inherited and acquired risk factors increase the risk of VTE. We evaluated the relationship between factor V (G1691A, A1090G, and A1299G), prothrombin (PT G20210A), methylenetetrahydrofolate reductase (MTHFR C677T) mutations, plasminogen activator inhibitor 1 (PAI-1 -675) polymorphism, and VTE in Turkish population. In all, 80 patients with VTE and 104 controls were included. Heterozygous factor V Leiden (FVL) mutation was significantly higher among patients ( P = .04) with allele frequency of 6.3% ( P = .01). Heterozygous PT G20210A mutation was also significantly higher among patients ( P = .001) with allele frequency of 6.9% ( P = .003). MTHFR 677TT genotype was significantly higher in patients ( P = .009) with allele frequency of 23.8% ( P = .005). No significant difference was found in FV A1090G and FV A1299G mutation rate as well as PAI-1 genotypes and their allele frequencies ( P > .05). Thus, frequencies of FV G1691A, PT G20210A, and MTHFR C677T mutations are higher in patients with VTE. FV A1090G, FV A1299G mutations, and PAI-1 gene polymorphisms may not be a risk factor for VTE in Turkish population.

Polymorphism A1/A2 in the cell surface integrin subunit β3 and disturbance of implantation and placentation in women with recurrent pregnancy loss

Polymorphism A1/A2 in the β3 subunit of integrins αIIb/β3 and αV/β3 is implicated in the risk of development of embryonic and fetal recurrent pregnancy loss (RPL). In 191 women with RPL, polymorphism A1/A2 was statistically significantly associated with RPL at <10 weeks of gestation (29.3% versus 16.4% in controls), but it was much more pronounced in 67 women with RPL between 10 and 20 weeks of gestation (41.8%), illustrating its role in recurrent fetal loss.

Levels of Platelet-Leukocyte Aggregates in Women With Both Thrombophilia and Recurrent Pregnancy Loss

The aim of our study was to investigate the significance of platelet-leukocyte aggregates (PLA) in women with recurrent pregnancy loss (RPL) as well as to identify association between common thrombophilic factors and whole blood levels of PLA in these patients. We measured PLA by whole blood flow cytometry in 66 nonpregnant women with hereditary and/or acquired thrombophilia and RPL, classified to 3 study groups, according to the type of losses (first, second, and third trimester) and 35 age-matched healthy controls. Platelet-leukocyte aggregates levels in all study groups were significantly increased compared to the control group (median values 2.13%, 2.32%, and 2.41%, vs median value in the control group 1.39%, P < .05 for all comparisons). Women with a single thrombophilic factor and women with combination of thrombophilic factors did not differ significantly as regards the PLA levels (2.13% vs 2.27%, P = .4). This study suggests that PLA may have a role in the pathogenesis of RPL in women affected by hereditary or acquired thrombophilia.