PLA2 polymorphism of platelet glycoprotein IIb/IIIa but not Factor V Leiden and prothrombin G20210A polymorphisms is associated with venous thromboembolism and more recurrent events in central Iran

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.

PlA2 Polymorphism in Glycoprotein IIb/IIIa Modulates the Morphology and Nanomechanics of Platelets

Glycoprotein IIb/IIIa (GPIIb/IIIa) is the most abundant platelet surface receptor for fibrinogen and von Willebrand factor. Polymorphism PlA1/A2 in the gene of GPIIb/IIIa is among the risk factors for the development of arterial and venous thrombosis. The aim of this study is to evaluate the effect of the carriage of PlA1/A2 on the size, topographic features, and membrane stiffness of platelets from healthy controls and patients with deep venous thrombosis (DVT). Atomic force microscopy (AFM) imaging and nanoindentation (force-distance curves) were applied to investigate the morphological and nanomechanical properties (Young's modulus) of platelets immobilized on glass surface. The surface roughness ( R_a) and height ( h) of platelets from patients with DVT, carriers of mutant allele PlA2 ( R_a = 30.2 ± 6 nm; h = 766 ± 182 nm) and noncarriers ( R_a = 28.6 ± 6 nm; h = 865 ± 290 nm), were lower than those of healthy carriers of allele PlA2 ( R_a = 48.1 ± 12 nm; h = 1072 ± 338 nm) and healthy noncarriers ( R_a = 49.7 ± 14 nm; h = 1021 ± 433 nm), respectively. Platelets isolated from patients with DVT, both carriers and noncarriers, exhibit much higher degree of stiffness at the stage of spreading ( E = 327 ± 85 kPa and 341 ± 102 kPa, respectively) compared to healthy noncarriers ( E = 198 ± 50 kPa). In addition, more pronounced level of platelet activation was found in polymorphism carriers. In conclusion, the carriage of PlA2 allele modulates the activation state, morphology, and membrane elasticity of platelets.

Rs5918ITGB3 Polymorphism, Smoking, and BMI as Risk Factors for Early Onset and Recurrence of DVT in Young Women

Objective:

To evaluate the contribution of rs5918ITGB3 on the incidence and recurrence of deep venous thrombosis (DVT) in women and the relationship with body mass index (BMI) and smoking and to compare with data in men.

Results:

Rs5918(C) polymorphism in ITGB3 gene was assessed in 224 patients diagnosed with DVT and 216 controls. Thrombophilic genetic variant rs5918(C) was significantly pronounced in women (χ2 =7.565, P = .008) and total patients (χ2 = 9.266, P = .002) but not in men. Women patients (<45 years) who were carriers of rs5918ITGB3 polymorphism had an early onset of DVT (34.5 vs 39.4 years, χ2 = 7.027, P = .008) as analyzed by Kaplan-Meier and a higher risk of the recurrent event (χ2 = 3.405, odds ratio = 2.581, P = .044). The period before recurrent venous thromboembolism event was related to smoking status and BMI in young female who were carriers of rs5918 polymorphism but not in the males.

Conclusions:

Carriage of genetic variant rs5918(C) polymorphism in ITGB3 gene in women contributes to higher risk of single and recurrent DVT events at younger age.

Genetic risk factors in patients with deep venous thrombosis, a retrospective case control study on Iranian population

Background

Venous thromboembolism (VTE) could be manifested as deep venous thrombosis (DVT) or pulmonary embolism (PE). DVT is usually the more common manifestation and is usually formation of a thrombus in the deep veins of lower extremities. DVT could occur without known underlying cause (idiopathic thrombosis) which could be a consequence of an inherited underlying risk factor or could be a consequence of provoking events, such as trauma, surgery or acute illness (provoked thrombosis). Our aim in this study was to assess the impact of some previously reported genetic risk factors including, methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C, plasminogen activator inhibitor-1(PAI-1) 4G/5G, prothrombin 20210 and FV Leiden on occurrence of DVT in a population of Iranian patients.

Methods

This long-term study was conducted on 182 patients with DVT and also 250 age and sex matched healthy subjects as control group. The diagnosis of DVT was based on patient’s history, clinical findings, D-dimer test, and confirmed by Doppler ultrasonography. After confirmation of DVT, both groups were assessed for the five mentioned mutations. The relationship between mutations and predisposition to DVT was calculated by using logistic regression and expressed as an OR with a 95 % confidence interval (CI).

Results

Our results revealed that FV Leiden (OR 6.7; 95 % CI = 2.2 to 20.3; P = 0.001), MTHFR C677T (OR 6.0; 95 % CI = 2.2 to 16.4; P < 0.001), MTHFR A1298C (OR 8.3; 95 % CI = 4.4 to 15.8; P < 0.001), and PAI-1 4G/5G (OR 3.8; 95 % CI = 2.1 to 7.2; P < 0.001) mutations were all significantly associated with an increased risk of DVT. Prothrombin 20210 was found in none of the patients and controls.

Conclusion

Our findings suggest that genetic risk factors have a contributory role on occurrence of DVT.

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.

Factor XIIIA-V34L and factor XIIIB-H95R in venous thromboembolism in central Iran: protective and neutral

Polymorphisms of coagulation factor XIII, an A2B2 tetramer, have been reported in correlation with venous and arterial thrombotic events. As there were limited data on these polymorphisms from Iranian population, we studied the correlation of factor XIIIA-Val34Leu and factor XIIIB-His95Arg with venous thromboembolism (VTE) in central Iran. Venous blood was collected from 102 unrelated VTE patients, diagnosed as pulmonary embolism, deep vein thrombosis (DVT), and pulmonary embolism/DVT and 165 healthy persons as control group. Genotyping was performed from DNA for FXIIIA-V34L and FXIIIB-H95R by polymerase chain reaction-restriction fragment length polymorphism and data were analyzed using Statistical Package for the Social Services software. There was no difference in age among the three groups of patients and between male and female participants. 41.02% of patients versus 42.04% of controls were carriers of FXIIIA-V34L as homozygous or heterozygous. Homozygosity of 34LL was significantly lower in patients compared with control participants (OR: 0.107, 95% CI: 0.14-0.83, P = 0.01) with only one homozygous in patients compared with 14 in the control group. Factor XIIIB-H95R was observed in 26.5% of patients versus 17.6% of control participants with no significant difference. There was no significant difference between patients and control group in homozygosity. Our findings on the frequency of FXIIIA-V34L is compatible with Caucasians. The significantly higher existence of homozygous 34LL in control participants is comparable with those who found it as protective against VTE. It may help to recognize risk factors or may contribute to prophylaxis in family members. We found FXIIIB-H95R polymorphism neutral. As there are different ethnicities in Iran, it may be beneficial to study other populations.