Venous thromboembolism in young patients from western India: a study

Prothrombin G20210A Mutation is Rare but not Absent Among North Indian Patients with Thromboembolic Events

Traditionally considered to be absent in India, prothrombin gene G20210A (NM_000506.5(F2): c.*97G > A) mutation (PGM) has recently been reported in few Indian patients. We aimed to assess the prevalence of PGM in patients with thromboembolic events from north India region. The thrombophilia workup comprising Protein C, Protein S, Antithrombin functional activity, lupus anticoagulant and anti-ACA and anti-ß2GP1 antibodies were performed in coagulation analyzer (ACLTOP-500, Instrumentation Laboratory, USA) and automated chemiluminescent assay analyzer (ACUSTAR, IL) respectively. PCR-RFLP was used to perform PGM and FVL mutation. Out of 509 patients, DVT and CVT/CSVT were identified in 208 and 250 patients respectively. A total of 42 (8.2%) cases showed inherited thrombophilia and 11 (2.1%) acquired thrombophilia. Among the inherited defects, the most common was FVL mutation 31 (6%) The PGM was seen in only 2/509 (0.3%) patients. The prevalence of PGM in North Indian patients with DVT, stroke and CVT is 0.41% (2/509). Although PGM is rare in this population, its presence emphasizes its association with these conditions. However, the role of PGM testing remains debatable due to its scarcity among North Indians.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12288-024-01741-x.

High Prevalence of Plasminogen Activator Inhibitor-1 4G/5G Polymorphism among Patients with Venous Thromboembolism in Kerala, India

Venous thromboembolism (VTE) is a multifactorial clotting disorder in which inherited and environmental factors synergistically contribute to its pathogenesis. The aim of this case-control study was to analyze the prevalence of hereditary thrombophilic risk factors, provoking and non-provoking environmental risk factors in patients with VTE from Kerala, India. We have observed a low prevalence of factor V Leiden (7%), prothrombin G20210A (2%), and prothrombin G20030A (2%) mutations and a high prevalence of plasminogen activator inhibitor-1 (PAI-1) 4G/5G (52%), PAI-1 4G/4G (24%) genotypes in the VTE patients (n = 147). Deficiency of anticoagulants, antithrombin (3.4%), and protein C (4.1%) was relatively low. None of the risk factors were observed in 17% of the patients. Majority of VTE patients were younger than 50 years with a median age of 43 years. In conclusion, our results indicate a high prevalence of PAI-1 4G/5G polymorphism among the VTE patients which is in concordance with previous studies in the Asian population. The PAI-1 4G/5G polymorphism could be a potential biomarker for assessing VTE risk, particularly among the Indian population.

Marburg I Polymorphism (G511E) in Adults with Deep Vein Thrombosis

The Marburg I polymorphism (G511E) in FSAP gene was listed as one of the risk factor for idiopathic DVT among the western population. The frequency of Marburg I polymorphism in India is presently not known. Fifty DVT cases and 50 healthy controls were tested for Marburg I polymorphism using ARMS-PCR technique. The thrombophilic risk factors (Protein C, Protein S, Antithrombin III, Factor V Leiden and antiphospholipid antibodies) were also determined. Marburg I polymorphism (heterozygous) was found in 2 patients (4%) but not in control subjects. These two cases did not have any other thrombophilia markers. Among the thrombophilic markers, heterozygous FVL mutation, PS, PC, AT deficiencies and antiphospholipid antibodies were seen in 10%, 10%, 6%, 6% and 8% of the patients respectively. The controls showed only the presence of antiphospholipid antibodies in 6% of subjects. Marburg I polymorphism among Indians DVT patients was determined for the first time. Its incidence was found in 4% of cases and not in controls. Although not statically significant this may be considered as one of the contributory risk factors for the development of DVT. A larger study is required for the validation of data.

Prothrombin gene mutations do not cause recurrent pregnancy loss in the Indian population

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High prevalence of factor V Leiden and prothrombin G20101A mutations in Kashmiri patients with venous thromboembolism

AIM

The genetic variants of the factor V (G1691A), prothrombin (G20210A) and MTHFR (C677T) genes have been widely implicated as inherited risk factors for developing venous thrombosis. This study was undertaken to reveal the frequency of these mutations in Kashmiri patients with venous thromboembolism.

METHODOLOGY

A case-control study was designed with 250 VTE patients and 250 healthy controls. The mutations were analysed using ARMS-PCR and PCR-RFLP approach.

RESULT

The factor V Leiden G1691A mutation was found in 17/250 (6.8%) VTE patients and prothrombin G20210A mutation was found in 7/250 (2.8%) VTE patients while no mutation was found in any of the healthy controls. Both the mutations were found to be significantly associated with the increased risk of VTE (p = 0.0001 and 0.0150 respectively) while no association of VTE risk with MTHFR C677T polymorphism was found (p = 0.53).

CONCLUSION

The increased frequency of factor V Leiden G1691A and prothrombin G20210A mutation in VTE patients indicates a significant role of these mutations in the development of VTE in our population. We therefore suggest the routine screening of these two mutations as thrombophilic markers in Kashmiri patients with venous thromboembolism.

Dysfunctional fibrinolysis and cerebral venous thrombosis

Cerebral venous thrombosis (CVT) is an uncommon neurological disease with high morbidity and mortality. Even after extensive thrombophilia screening, majority of the thrombosis cases remain with unknown etiology. Hypofibrinolysis due to acquired or congenital deficiencies or abnormalities in factors in the fibrinolytic cascade is a known cause of thrombosis at any site. In the present study 104 cases of radiologically confirmed CVT cases were investigated for the conventional thrombophilia along with factors in the fibrinolytic cascade to find a possible etiology for the clinical manifestation. Conventional thrombophilia markers which included PC, PS, AT and FVL mutation were detected in 16.3% of the patients. Approximately 19% cases had grossly elevated plasma PAI-1 levels. PAI-1 4G/4G genotype was found to be strongly associated with high PAI-1 levels. 2.9% cases had reduced tPA levels, 1.9% had plasminogen deficiency and 1.9% cases had increased alpha-2-antiplasmin levels. Along with conventional thrombophilia, dysfunctional fibrinolysis is found to be strongly associated with CVT. Understanding the role of risk factors is important for appropriate treatment of this serious disorder.

Study of associated genetic variants in Indian subjects reveals the basis of ethnicity related differences in susceptibility to venous thromboembolism

The genetic variants linked with the susceptibility of individuals to VTE are well known; however, the studies explaining the ethnicity based difference in susceptibility to VTE are limited. Present study assesses mutations in six candidate genes contributing to the etiology of VTE in Indian subjects. The study comprised 93 VTE patients and 102 healthy controls. A PCR-RFLP based analysis was performed for nine mutations in the following genes associated with VTE: favtor V Leiden (FVL), prothrombin, tissue factor pathway inhibitor (TFPI), fibrinogen-beta, plasminogen activator inhibitor 1 (PAI-1), and methylene tetrahydrofolatereductase (MTHFR). All the subjects were found to be monomorphic for FVL 1691G/A, prothrombin 20210G/A and TFPI −536C/T mutations. The mutation in the MTHFR gene (677C/T) was observed only in patients. Contrarily, higher frequency of mutation in the PAI-1 −844G/A and the fibrinogen-β −455G/A was observed in controls in comparison to the patients. This study suggests that the PAI-1 −844G/A and fibrinogen-β −455G/A could be protective variants against VTE in Indians. While MTHFR 677C/T mutation was found to be associated, in contrast to other populations, the established genetic variants FVL 1691G/A, prothrombin 20210G/A, and TFPI −536C/T may not be associated with VTE in Indians thus revealing the basis of ethnicity related differences in susceptibility of Indians to VTE.

The Prevalence of the Prothrombin (F2) 20210G>A Mutation in a Cohort of Sri Lankan Patients with Thromboembolic Disorders

Prothrombin (F2) 20210G>A [rs1799963 G>A] mutation is a genetic variant which predisposes to inherited thrombophilia. Highest prevalence of this rare mutation has been reported among Caucasian and Mediterranean populations with thrombophilic conditions compared to healthy controls. It is absent or occurs in a very low frequency in both thrombophilic patients and healthy controls of most South Asian populations. A previous study has demonstrated that the mutant allele is absent among Sri Lankan healthy controls. This study was conducted to determine the prevalence of the F2 20210G>A mutation among Sri Lankan patients with thrombo-embolic disorders. F2 20210G>A mutation analysis was carried out on 825 patients. These included 374 with arterial thromboembolic disorders, 303 with venous thromboembolic disorders (VTE) and 148 with pregnancy related complications. Genotyping was done using polymerase chain reaction followed by restriction fragment length polymorphism. The overall prevalence of the individuals detected with the mutation was 0.8 % (7/825) with a mutant allele frequency of 0.4 % (7/1,650), and all were heterozygotes. Further classification according to the types of thrombotic events showed a prevalence of 0.5 % (2/374), 1.3 % (4/303), and 0.7 % (1/148) respectively, in the three groups with arterial thrombosis, VTE and pregnancy complications. The respective mutant allele frequencies in the three different groups were 0.3 % (2/748), 0.7 % (4/606) and 0.3 % (1/296). Although these figures are lower than that of Caucasian and Mediterranean populations, they are relatively higher compared to other South Asian populations. Therefore, the F2 20210G>A mutant allele is not entirely absent among Sri Lankan patients with thrombo-embolic disorders.

Risk of Budd-Chiari syndrome associated with factor V Leiden and G20210A prothrombin mutation: a meta-analysis

Background

Various studies have demonstrated that factor V Leiden (FVL) and G20210A prothrombin mutation contribute to the risk of Budd-Chiari syndrome (BCS), while other studies provided conflicting findings. In order to derive more precise estimations of the relationships, a meta-analysis was performed.

Methods

Eligible articles were identified through search of databases including Pubmed, Chinese Biomedical Database (CBM, Chinese), and Chinese National Knowledge Infrastructure (CNKI, Chinese). Odd ratios (ORs) with 95% confidence intervals (CIs) were calculated using random- or fixed- model.

Results

Finally, twelve studies were included for FVL and nine studies were included for G20210A prothrombin mutation. With respect to FVL, significantly increased BCS risk was found in the overall population (OR = 6.29, 95%CI = 4.23–9.36). Subgroup analyses suggested that FVL was associated with an increased risk of BCS in the population with high background mutation prevalence (>1% in the normal population). No significant association was found between BCS and G20210A prothrombin mutation (OR = 1.78, 95%CI = 0.77–4.11).

Conclusion

The presence of FVL should be evaluated in patients with BCS. Conversely, G20210A prothrombin mutation is not significantly associated with risk of BCS. Large-scale well designed studies are necessary to be conducted to further confirm or refute the observed association.

Hereditary and Acquired Thrombophilia in Splanchnic Vein Thrombosis: A Single-Center Experience

The purpose of this study was to characterize differences in the prevalence of hereditary and acquired thrombophilia in patients with splanchnic vein thrombosis (SVT). A total of 88 consecutive patients with SVT, including Budd Chiari Syndrome (n = 47) and portal extrahepatic portal vein obstruction (n = 41), underwent comprehensive thrombophilia testing, including testing for heritable and acquired causes. In 33 (37.5%) patients, etiology could be explained by at least 1 of the heritable etiologic factors, and 31 (35.2%) patients could be explained by at least 1 of the acquired causes studied. The combination of multiple concurrent factors was present in 9 (11.4%) patients. Among the heritable causes, the risk of SVT was found increased in the presence of thrombophilia resulting from the deficiencies of the naturally occurring anticoagulant proteins, and the acquired thrombogenic factors were significantly associated with causation of thrombosis in adult patients with SVT.

Acquired and Heritable Thrombophilia in Indian Patients With Pediatric Deep Venous Thrombosis (DVT)

Deep venous thrombosis (DVT) in children is more often associated with underlying pathological conditions than with hereditary thrombophilia. The present study is a retrospective analysis of thrombophilia in 285 pediatric patients with venous thrombosis at different sites. Four common thrombophilia markers, that is protein C, protein S, antithrombin III, and factor V Leiden (FVL) mutation, were analyzed. Thrombosis in hepatic and portal veins was more common in pediatric patients (73%) when compared to other sites (27%). Overall, hereditary thrombophilia accounted for 15.5% of the patients with venous thrombosis. The FVL mutation, which was the major causative factor in Budd-Chiari syndrome and portal vein thrombosis cases in the adult group, was not a major contributing factor in pediatric group, that is, 1.8% of the patients. In conclusion, the risk factors for venous thrombosis vary in different age groups.

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.

Factor V-Leiden Mutation: A Common Risk Factor for Venous Thrombosis among Lebanese Patients

Aim. Lebanon exhibits one of the highest prevalences of factor V-Leiden (FVL) in the world (14.4%). The aim of this study is to evaluate the incidence of FVL mutation among Lebanese patients with lower extremity venous thrombosis. Material and Methods. From January 2003 to January 2011, 283 consecutive Lebanese patients, diagnosed with deep venous thrombosis (DVT) by duplex scan, were retrospectively reviewed. FVL mutation was tested among patients with conditions highly suggestive of hypercoagulation states (65 patients). Results. FVL mutation was detected among 56.9% of patients, 68.6% of patients younger than 50 years, and 43.4% of patients older than 50 years (P = 0.041). FVL mutation was commonly reported in young adults, in patients with pregnancy, estrogen drugs, recurrent DVT, and resistance to anticoagulation. Conclusion. The high rate of FVL mutation observed among Lebanese patients with venous thrombosis is related to the high prevalence of this mutation in the Lebanese population. Thrombophilia screening should be tailored to accommodate a population's risk factor. In countries with high prevalence of FVL, this mutation should be screened among patients younger than 50 years and patients with situations highly suggestive of hypercoagulation states.

Hereditary protein C deficiency in Indian patients with venous thrombosis

Approximately, 4-11 % of the patients with idiopathic venous thrombosis (VT) show protein C (PC) deficiency. The molecular pathology of PC deficiency was analyzed in 102 patients; 98 healthy controls were also studied to assess the association of various polymorphisms with reduced PC levels. PROC gene mutations were detected only in 8 (7.8 %) patients with reduced PC levels. PROC promoter region CG polymorphisms showed statistically significant association with reduced PC levels (p < 0.001). PC deficiency in Indian VT patients can, thus, largely be explained by PROC gene promoter CG polymorphisms; only a small fraction of the patients show specific mutations in PROC gene.

Lower extremity venous thrombosis in patients younger than 50 years of age

Aim

Lower extremity deep venous thrombosis in the young adult is uncommon and has not been well studied in the literature. The aim of this study is to define risk factors for deep venous thrombosis among patients younger than 50 years of age, to compare them with a control group, and to suggest recommendations for the management and treatment of venous thrombosis in this particular group of patients.

Methods

From January 2003 to January 2011, 66 consecutive Lebanese patients (29 males and 37 females) younger than 50 years, diagnosed in an academic tertiary-care center with lower extremity deep venous thrombosis by color flow duplex scan, were retrospectively reviewed. Their age varied between 21 and 50 years (mean 38.7 years). The control group included 217 patients (86 males and 131 females) older than 50 years (range: 50–96 years; mean 72.9 years).

Results

The most commonly reported risk factors in the younger age group were inherited thrombophilia (46.9% compared with 13.8% in the control group; P < 0.001), pregnancy (18.2% compared with 0.5%; P < 0.001), treatment with estrogen drugs (13.6% compared with 2.3%; P = 0.001), and family history of venous thromboembolism (9.1% compared with 3.8%; P = 0.084).

Conclusion

Inherited thrombophilia is the most commonly observed risk factor among patients younger than 50 years, with a prevalence of three times more than the control group. Young adults should be screened for thrombophilia even in the presence of transient acquired risk factors. Pregnancy and treatment with estrogen drugs essentially when associated with inherited thrombophilia represent a frequent cause of venous thrombosis among young female patients. Inferior vena cava abnormalities should be excluded in young patients with spontaneous proximal venous thrombosis especially when recurrent venous thrombosis or resistance to anticoagulation are observed.

Epidemiology of Prothrombin G20210A Mutation in the Mediterranean Region

There are many genetic and acquired risk factors that are known to cause venous thromboembolic disorders (VTE). One of these is the Prothrombin G20210A mutation, which has been identified in 1996. Prothrombin G20210A mutation causes higher levels of the clotting factor prothrombin in the blood of carriers, which creates a higher tendency towards blood clotting (hypercoagulability), and therefore the carriers become at higher risk of developing VTE. High prevalence of Prothrombin G20210A mutation was reported in Caucasian populations, but the prevalence was almost absent in non-Caucasians. That was most obvious in countries of South Europe and the Mediterranean region. This review article discusses Prothrombin G20210A mutation, how it causes VTE, the origin of the mutation, and its distribution worldwide with special concentration on the Mediterranean area.

Coagulation disorders seen through the window of molecular biology

Coagulation disorders have been traditionally worked up by their clinical phenotypes and coagulation factor assays which are dependent on APTT- and PT-based techniques. Development of chromogenic substrates in the late seventies and early eighties allowed coagulation factors to be measured like enzymes. There was still a major lacuna in the understanding of the biology of different coagulation disorders. Modern molecular biology - which developed as an unique synthesis of biochemistry, immunology, cell biology, and genetics - allowed us to have a more comprehensive understanding of the pathobiology of many of these coagulation disorders. This overview presents several examples which show how we have enriched our understanding about the varied clinical phenotypes of different coagulation disorders.

Epidemiology of activated protein C resistance and factor v leiden mutation in the mediterranean region

Venous thromboembolic disorders (VTE) are serious disorders with high morbidity and mortality rates. Many genetic and acquired risk factors were identified to cause VTE. The most common genetic risk factor is Factor V Leiden mutation (FVL). FVL was found in high percentage of populations of Caucasian origin but was almost absent in non-Caucasians. It was also reported in populations living in North Africa and the Middle East. This review article briefly explains FVL and how it causes VTE, the distribution of FVL worldwide, and then it elaborates on the epidemiology of FVL in the Mediterranean Region and how this brought speculations that FVL might have originated in the Eastern Mediterranean area.

Hemostasis research in India: past, present, and future

Hemostasis research in India has a long history considering the fact that it is one of the youngest specialities in the world. If we take creation of prothrombin time (PT) test as one of the beginning of modern hemostsis research, then the specialty is no older than 60 years. School of Tropical Medicine Kolkata, Banaras Hindu University, All India Institute of Medical Sciences at Delhi, Christian Medical College at Vellore, Post Graduate Institute of Medical Education and Research at Chandigarh, and KEM Hospital at Mumbai contributed substantially in defining various bleeding disorders in our country. Unfortunately, some of these institutes are no longer as active in the field as they used to be. Currently, the Institute of Immunohaematology at Mumbai, Chrstian medical College at Vellore, and All India Institute of Medical Sciences at Delhi are actively engaged in hemostsis research in India. Developing prenatal diagnostic technologies, mutation detection of various hemostatic disorders, developing low-cost management technologies for hemophilia, and other bleeding disorders are becoming important present day research activity in the area of hemostasis in addition to age old areas of prevalence and unusual case description studies. Entry of many new corporate hospitals, development of structured postgraduate training program in hematology, and easy availability of instruments and reagents are likely to foster further growth in this area of medical research in India in future.

Haematology research in India: past, present and future

Haematology research in India is relatively recent in origin. However the pioneers in the field not only did exemplary work when compared to advanced western countries, they also made it a point to develop centres of excellence and human resources for future of haematology work in this country. In this brief overview an effort has been made to give a taste of quality and expanse of haematology research in this country. This review does not claim to have described every bit of haematology research in this country. Our pioneers worked under extremely difficult and trying circumstances on a subject which was limited to funding available from Indian Council of Medical Research. Now the times have changed, several funding agencies in the country are able to provide substantial fund for research. Modern state of the art basic research institutions are tying up with medical colleges for good quality research and the seeds which our pioneers had planted have grown into a mighty tree. It would not be an exaggeration to say we are on the threshold of the golden era of haematology research in this country.

JAK2 mutations across a spectrum of venous thrombosis cases

The JAK2(V617F)mutation is recurrent in polycythemia vera and essential thrombocythemia, which are myeloproliferative neoplasms frequently associated with arterial and venous thromboembolism. It has also been reported as a marker for occult myeloproliferative disorder (MPD) in patients with splanchnic venous thrombosis. Limited data are available regarding the prevalence of the JAK2(V617F) mutation in patients with thrombosis outside the splanchnic region. For the study, 321 cases of venous thrombosis in the splanchnic and nonsplanchnic regions (cerebral venous thrombosis [CVT], 70; deep venous thrombosis [DVT], 36; Budd-Chiari syndrome [BCS], 137; portal venous thrombosis [PVT], 78) were studied for the presence of JAK2 mutations. The prevalence values for the JAK2 mutation were 3% (1/36), 8.8% (12/137), 5% (4/78), and 3% (2/70) in DVT, BCS, PVT, and CVT, respectively; 19 (5.9%) of 321 cases were positive for the JAK2 mutation. Of 111 healthy subjects screened for this mutation, none were found to be carriers. Determination of the JAK2(V617F) mutation may be useful to identify patients who should be carefully observed for the development of overt MPDs. The significance of screening for this mutation in nonsplanchnic thrombosis cases needs to be analyzed in a larger series.

Prevalence of common thrombophilia markers and risk factors in Indian patients with primary venous thrombosis

CONTEXT AND OBJECTIVE

venous thrombosis occurs as a result of interaction of genetic and acquired factors including activated protein C resistance (APC-R), fibrinogen levels, antithrombin, protein C, protein S, lupus anticoagulants and anticardiolipin antibodies. This study was aimed at determining the prevalence of these common thrombophilia markers in Asian Indians with primary venous thrombosis.

DESIGN AND SETTING

this was a cross-sectional study carried out in Mumbai.

METHODS

samples from 78 patients with a confirmed diagnosis of venous thrombosis and 50 controls were tested. Semi-quantitative estimation (functional assays) of protein C, protein S and antithrombin was performed. Quantitative estimation of fibrinogen was done using the Clauss method. Lupus anticoagulants were screened using lupus-sensitive activated partial thromboplastin time and β2-glycoprotein-I dependent anticardiolipin antibodies were estimated by ELISA. APC-R was measured using a clotting-based method with factor V deficient plasma and Crotalus viridis venom. Statistical analysis was performed using Epi-info (version 6).

RESULTS

the popliteal vein was the most commonly involved site. Forty-four samples (56%) gave abnormal results. The commonest were elevated fibrinogen and APC-R (17.9% each), followed by low protein S (16.6%).

CONCLUSIONS

this study confirms the literature findings that fibrinogen level estimation and screening for APC-R are important for the work-up on venous thrombosis patients since these, singly or in combination, may lead to a primary thrombotic episode. The frequency of the other thrombophilia markers was higher among the patients than among the controls, but without statistically significant difference.

Differences in Etiological and Clinical Manifestations in Upper Extremity and Lower Limb Deep Venous Thrombosis Patients From India

We assessed the clinical manifestations in upper and lower limb deep venous thrombosis patients from India and difference in etiological factors. Fifty-three patients with primary upper extremity deep vein thrombosis (UEDVT; males 30, females 23) and 236 patients with lower limb deep vein thrombosis (LLDVT; males 157, females 79) were included in this study. The thrombophilia markers studied were protein C (PC), protein S (PS), antithrombin (AT) III, and factor V Leiden (FVL) mutation. Females had significantly higher prevalence of prothrombotic markers as compared to males (P = .046) in the UEDVT group. No statistically significant differences in the prevalence of prothrombotic markers were observed between the LLDVT and the UEDVT patients. The clinical picture however revealed greater involvement of thrombus of the iliofemoral vein (P = .009) and the proximal tibial vein (P = .005) in males than females, while no differences were observed in the clinical manifestations between the 2 sexes in UEDVT patients. Our study is able to give a broad perspective of the prevalence data of UEDVT and LLDVT in the city of Mumbai of approximately 5 million population served by this hospital. We conclude that the topology of thrombosis in deep vein thrombosis (DVT) patients in India is different from that of the Western countries.

Radiological and histological changes following cerebral venous sinus thrombosis in a rat model

Cerebral venous sinus thrombosis (CVST) is an important cause of stroke in young especially after pregnancy. We induced CVST in rat by topical application of ferric chloride over the exposed superior sagittal sinus (SSS) and pathological changes were monitored on days 1, 2 and 7. Thrombus weight was estimated and H&E staining was performed for comparison with MRI data. T2 weighted signal changes were present in all the study group rats. T2 hyper intensity decreased over the time. In study group, the apparent diffusion coefficient (ADC) was decreased by 31.94% on day 1 compared to the controls. There was 15.5% increase in the ADC value on day 2 compared to day 1 which reached almost equal to control value on day 7. On histological evaluation, neuronal necrosis and cellular infiltration were observed in cortical region after thrombosis. The early decrease in ADC could be attributed to cytotoxic edema that precedes vasogenic edema indicated by normalization of ADC and a decreased T2 hyper intensity. In conclusion, ferric chloride induced CVST in the rat produces cytotoxic edema in early stage followed by vasogenic edema which is related to recanalization of the superior sagittal sinus.

Risk factors for deep vein thrombosis in women aged 18 to 50: a retrospective analysis

BACKGROUND

Deep vein thrombosis (DVT) occurs in one of every 1,000 individuals per year. Various inherited and acquired risk factors are known. We investigated the importance of oral contraceptives (OCs) as a risk factor in women of child-bearing age.

OBJECTIVES

To evaluate the risk factors for DVT in a female patient collective.

METHODS

We analyzed the records of 99 women aged 18 to 50 with DVT. We documented age, identifiable risk factor of DVT, location of the thrombus, use of OCs, and thrombophilia.

RESULTS

52.5% of patients suffering from DVT were aged between 40-50 years. Forty-six patients had an unprovoked DVT; the most common risk factor was immobilization in 41. Thrombophilia was found in 18 cases. Twenty-nine patients used OCs; no influence of OCs on any of the other risk factors was found.

CONCLUSIONS

In our patient group, the most important risk factors were older age and immobilization. DVT is typically idiopathic and may be caused by subtle nondetectable thrombophilic disorders. The use of OCs was distributed in DVT patients just as in the general Austrian community and seems not to be a severe additional risk factor. Examining the whole lower extremity during ultrasonography is important so as not to overlook a DVT of the lower leg.

Activated protein C resistance in deep venous thrombosis

Several risk factors for deep venous thrombosis (DVT) have been identified, and inherited thrombophilias constitute a significant proportion of them. The most common inherited thrombophilia is activated protein C (APC) resistance, and factor V Leiden is the most common cause of APC resistance. The high prevalence of APC resistance in Caucasians is established, and the prevalence among persons of Asian and African descent has been shown to be low in previous studies. Twenty-three patients with lower limb DVT were included in the study. Diagnosis was confirmed by duplex ultrasonography. Patients were tested for APC resistance with use of the STA Staclot APC-R system (Diagnostica Stago, Asnieres, France), as per the manufacturer's guidelines. Ten patients (43.5%) tested positive for APC resistance, while 13 (56.5%) tested negative. APC resistance, although considered a rarity, has been found to have a high prevalence in patients with DVT from the northeastern region of India. APC resistance estimation should be done for all patients with DVT.

Contribution of natural anticoagulant and fibrinolytic factors in modulating the clinical severity of haemophilia patients

The role of natural anticoagulants, fibrinolytic cascade factors and common prothrombotic gene polymorphisms in modulating disease severity were studied in 35 'clinically mild' and 37 'clinically severe' haemophilia patients with severe factor VIII or IX deficiency (<0.01 IU/ml). Strong association of deficiencies of proteins C and S, antithrombin III, tissue factor pathway inhibitor and tissue plasminogen activator, together with factor V Leiden and endothelial protein C receptor 23 bp insertion polymorphisms were observed in the 'clinically milder' group as compared with the 'clinically severe' group. These results indicate a synergistic modulation of bleeding tendency in haemophilia patients by factors in the anticoagulant and fibrinolytic systems.

Deep venous thrombosis in the antenatal period in a large cohort of pregnancies from western India

BACKGROUND

Deep venous thrombosis (DVT) is an important complication in the peripartal and postpartal period.

METHODS

We followed up prospectively the prevalence of DVT in 34720 prenatal mothers between June 2002 and July 2006 attending the antenatal clinics of two major hospitals in Mumbai, India. Thirty two women (0.1%) presented for the first time with symptomatic DVT i.e. 17 in the first trimester, 6 in the second and 9 in the third trimester of pregnancy. Nine had history of fetal loss while in the remaining twenty three there was no history of fetal loss.

RESULTS

The evaluation of both acquired and heritable thrombophilia showed a conglomeration of thrombophilia in this group when compared to 100 normal pregnant women who have given birth to at least one healthy baby with no history of fetal death, DVT or other obstetrical complications. The relative risks for all the antiphospholipid antibodies (APA) studied i.e lupus anticoagulant (LA), IgG/IgM antibodies for cardiolipin (ACA), beta2 glycoprotein 1 (beta2 GP 1) and annexin V were significantly higher in women with pregnancy associated DVT (RR 7.4 95% CI 4.3-11.3 P < 0.05). Among the genetic thrombophilia markers studied, Protein S (PS) deficiency was the strongest risk factor (RR 5.00 95% CI 3.02-5.00 P < 0.05) followed by factor V Leiden (FVL) mutation (RR 4.57 95% CI 2.23-4.57 P < 0.05) and PAI 4G/4G homozygosity (RR 3.24 95% CI 1.85-5.12 P < 0.05). Protein C (PC) and endothelial protein C receptor (EPCR) 23 bp insertion polymorphism was also increased in the patient group as compared to controls but the difference was not statistically significant. The MTHFR C677T, fibrinogen gene beta448 Arg/Lys polymorphisms were not significantly different from the normal controls, while antithrombin III (AT III) deficiency and PT G20210A polymorphism were absent in both controls and patients. Two or more risk factors were present in 22 out of 32 cases (68.75%).

CONCLUSION

We conclude that the prevalence of DVT in India is more or less similar to other reports published and both acquired and heritable thrombophilia show strong association with DVT associated with pregnancy.

The prothrombin gene G20210A variant and puerperal cerebral venous and sinus thrombosis in South Indian women

Pregnancy and puerperium raise the risk of thrombotic events, and these risks are likely to be increased in women who are carriers of thrombophilic gene polymorphisms. Prothrombin G20210A variant is reported to be the second most frequent prothrombotic polymorphism in Caucasians. Our aim was to determine the prevalence of this variant in south Indian women and examine its association with cerebral venous and sinus thrombosis occurring during puerperium. We investigated 96 women with puerperal cerebral veno-sinus thrombosis (CVT) and 103 age-matched women with no post-partum complications. We used restriction fragment length polymorphism analysis to identify their genotypes. The prothrombin G20210A variant was not detected in either the CVT patients or the healthy control subjects. Our study on a large series of patients with puerperal CVT shows that the prothrombin G20210A variant is not present in south Indian women and is not associated with puerperal CVT. This study also highlights the fact that there are racial differences in the risk factors for thrombosis, which should be considered when investigating these patients.

Hyperhomocysteinemia and the compound heterozygous state for methylene tetrahydrofolate reductase are independent risk factors for deep vein thrombosis among South Indians

To investigate the role of methylene tetrahydrofolate reductase (MTHFR) (677 C-->T and 1298 A-->C), factor V (1691 G-->A), factor II (20210 G-->A) genetic polymorphisms and hyperhomocysteinemia in the aetiology of deep vein thrombosis (DVT) in 163 cases and 163 controls. Polymerase chain reaction-restriction fragment length polymorphism was used for genotyping, reverse-phase high-performance liquid chromatography for plasma homocysteine, and Student's t-test and Fisher exact tests were used for statistical analysis. Elevated mean plasma homocysteine levels were observed in DVT cases irrespective of gender differences. Homocysteine elevation above the 95th percentile of the control group associated with 9.4-fold and 7.6-fold increased risk for DVT in men and women, respectively. Genotyping showed the MTHFR 677CT/1298AC genotype (i.e. compound heterozygosity) is associated with 3.5-fold risk for thrombosis. The factor V Leiden mutation frequency was higher in DVT cases, but not statistically significant; however, genetic predisposition to this mutation was associated with early age of DVT onset. Factor II mutation was absent in cases and controls. Co-segregation of two or more risk factors was associated with 11.7-fold increased risk for thrombosis. This study projects that hyperhomocysteinemia and compound heterozygous state for MTHFR are independent risk factors for DVT among South Indians.

Thrombophilic gene polymorphisms in puerperal cerebral veno-sinus thrombosis

Puerperal cerebral veno-sinus thrombosis (PCVT) is a common form of stroke in young women in India, which is associated with high morbidity and mortality. The frequency of PCVT in India is 10 to 12 times more compared to western population. As yet, the etiology of this condition is unclear. Our aim was to study the prevalence and the role of the common genetic polymorphisms associated with thrombophilia such as factor V Leiden, prothrombin G20210A and methylene tetrahydrofolate reductase (MTHFR) C677T, in aseptic PCVT. We investigated 86 women with PCVT and 86 age-matched women with no post-partum complications. Polymerase chain reaction (PCR)/restriction fragment length polymorphism analysis was used to identify their genotypes. The frequency of the three polymorphisms in cases and controls were: factor V Leiden, 2.3% versus 1.2% (OR 0.49, 95% CI=0.02-7.12, p=1.000) and MTHFR C677T, 16.3% versus 17.4% (OR 0.92, 95% CI=0.39-2.19, p=0.838). The prothrombin G20210A variant was not detected in either patients or controls. The clinical characteristics of the PCVT patients with the polymorphisms did not differ significantly from those without them. In our series of PCVT patients, the risk associated with the established thrombophilic risk factors is insignificant. Exploration of these gene polymorphisms seems to be of limited value in the investigation of PCVT in south Indian women.

Prothrombin G20210A gene variant is not associated with idiopathic portal vein thrombosis in an area endemic for portal vein thrombosis

Prothrombin G20210A gene variant has been found in 0-23% of patients with portal vein thrombosis (PVT). This wide variation makes it difficult to assess the importance of prothrombin G20210A gene variant as a predisposing factor for PVT. In this study from South India, none of the patients with idiopathic PVT (0/38) or any of the controls (0/46) had prothrombin G20210A gene variant. Prothrombin G20210A gene variant does not contribute to the development of PVT in India.

Methylenetetrahydrofolate reductase (MTHFR) c677t gene variant modulates the homocysteine folate correlation in a mild folate-deficient population

BACKGROUND

A large body of evidence links plasma concentrations of homocysteine and cardiovascular disease. Several genetic and environmental variables may modulate such relationship. We investigated the influence of methylenetetrahydrofolate reductase (MTHFR) gene variants C677T, A1298C, and T1317C on homocysteine, folate, and cobalamin concentrations in a sample of individuals from a mild folate deficiency population to better clarify the complex interactions existing among these variables.

METHODS

In the present study, 209 individuals belonging to an admixed urban population characterized by mild folate deficiency were investigated. MTHFR gene variants C677T, A1298C, and T1317C were genotyped and homocysteine-, folate-, and cobalamin-determined for each individual.

RESULTS

Univariate analyses showed a significant association between the C677T variant with homocysteine (P<0.001) and cobalamin (P=0.005) as well as a significant relationship between the T allele and serum folate concentrations (P<0.05). The TT genotype of the C677T polymorphism remained significantly associated with log-transformed homocysteine even after adjustment for age, sex, smoking status, ethnicity, folate, and cobalamin concentrations (P<0.01). Both univariate and multivariate analysis have failed to show any effect of the A1298C and T1317C genetic variants in homocysteine concentrations in this population. Finally, a significant interaction between folate and C677T polymorphism in the determination of homocysteine was also disclosed (P<0.005).

CONCLUSIONS

Taken together, these results demonstrate a significant interaction between serum folate and MTHFR genotype in predicting homocysteine concentrations. One may consider that a differential response of homocysteine to folic acid supplementation may depend on MTHFR genotype which may have important implications when attempting to lower homocysteine concentrations in populations with mild folate deficiency.