Plasma Proteome Database as a resource for proteomics research: 2014 update.

Plasma Proteome Database (PPD; http://www.plasmaproteomedatabase.org/) was initially described in the year 2005 as a part of Human Proteome Organization's (HUPO's) pilot initiative on Human Plasma Proteome Project. Since then, improvements in proteomic technologies and increased throughput have led to identification of a large number of novel plasma proteins. To keep up with this increase in data, we have significantly enriched the proteomic information in PPD. This database currently contains information on 10,546 proteins detected in serum/plasma of which 3784 have been reported in two or more studies. The latest version of the database also incorporates mass spectrometry-derived data including experimentally verified proteotypic peptides used for multiple reaction monitoring assays. Other novel features include published plasma/serum concentrations for 1278 proteins along with a separate category of plasma-derived extracellular vesicle proteins. As plasma proteins have become a major thrust in the field of biomarkers, we have enabled a batch-based query designated Plasma Proteome Explorer, which will permit the users in screening a list of proteins or peptides against known plasma proteins to assess novelty of their data set. We believe that PPD will facilitate both clinical and basic research by serving as a comprehensive reference of plasma proteins in humans and accelerate biomarker discovery and translation efforts.

Proteomic Signature of Endothelial Dysfunction Identified in the Serum of Acute Ischemic Stroke Patients by the iTRAQ-Based LC-MS Approach.

Acute ischemic stroke (AIS) is a devastating cerebrovascular disorder that leads to permanent physical and neurological disabilities in adults worldwide. Proteins associated with stroke pathogenesis may appear in the serum of AIS patients due to blood-brain barrier dysfunction, thus permitting the development of blood-based biomarkers for early diagnosis of stroke. These biomarkers could perhaps be an adjunct to the existing imaging modalities and aid in better management and therapeutic intervention during the course of the disease. For this exploratory study, a combination of multiplexed isobaric tagging using iTRAQ reagents and high resolution tandem mass spectrometry was used to identify differentially expressed proteins in serum samples from AIS patients. The quantitative proteomic analysis of serum from both AIS and control subjects revealed 389 high confidence protein identifications and their relative levels. Among them, 60 proteins showed a ≥1.5-fold change in the AIS subjects. We verified the altered serum levels of candidate proteins such as vWF, ADAMTS13, S100A7, and DLG4 through ELISA, and the results also corroborate with the experimental findings. vWF and ADAMTS13 are key players that regulate blood hemostasis, and their altered concentration may contribute to endothelial dysfunction. S100A7 is a novel candidate protein identified in this study that is also known to mediate inflammation, endothelial proliferation, and angiogenesis. The current study provided a potential and novel biomarker panel that may in turn provide diagnostic aid to the existing imaging modalities for the rapid diagnosis of ischemic stroke.

Postnatal variations in blood free and acylcarnitines.

BACKGROUND: Alteration in concentrations of blood carnitine and its esters are diagnostic of a number of inherited metabolic disorders. Acylcarnitine (AC) profiles of newborns obtained from dried blood spots by tandem mass spectrometric analysis are being used for the diagnosis of these disorders. There are no data of the postnatal variations of free carnitine (FC) and AC in Indian neonates. OBJECTIVES: Evaluation of postnatal variations in free and AC levels in newborns. METHODS: Blood FC and AC levels were evaluated in 2,727 healthy neonates of postnatal day 2-30 by electrospray ionization tandem mass spectrometry. RESULTS: Blood C2, C5DC, C16, C16:1, C18, C18:1, C18:2, and C18:OH carnitines were increased in groups A (aged 8-14 days) and B (aged 15-30 days), compared with the control group (aged 2-7 days), whereas C3, C4, C4OH, C6, C6DC, and C12 carnitines were increased only in group B. No sex-related differences were found except for C3DC, C4, and C5 carnitine concentrations, which were higher in female neonates. CONCLUSIONS: Our data can be used as a reference for the assessment of carnitine status in Indian newborns, hence reducing the risk of misdiagnosis of fatty acid oxidation disorders and organic acidemias during interpretation of the results of tandem mass spectrometry-based newborn screening.

Association of the functional KL-VS variant of Klotho gene with early-onset ischemic stroke.

Genetic variants of Klotho have been reported to be associated with human longevity and atherosclerotic vascular events and risk factors. However, very few studies have explored their association with ischemic stroke. We hypothesized that the functional KL-VS and the exonic C1818T variants of Klotho gene may be associated with ischemic stroke in Indian population. We enrolled a total of 460 patients with ischemic stroke and 574 age- and gender-matched controls for the study. Genotyping was done by polymerase chain reaction and restriction fragment length polymorphism. Contrary to other Asian reports, KL-VS variant was polymorphic in our population, with a frequency distribution similar to that of Caucasians. The frequency distribution of the C1818T variant was similar to previously reports in Asians. A differential effect of age on association of Klotho KL-VS variant with ischemic stroke was observed. In subjects aged ≤40 years, the KL-VS homozygotes, 352FF and 352VV, had ~1.5-fold (OR=1.57; 95% CI: 1.02-2.40, p=0.038) and ~3-fold (OR=3.29; 95%CI: 1.02-10.56, p=0.046) higher risk of stroke compared to heterozygotes, whereas in the older group (aged >40 years) no significant association was observed. The C1818T variant was not associated with ischemic stroke. We conclude that KL-VS homozygosity could contribute to early-onset stroke in India. Larger studies in other ethnic populations are warranted to determine the role of these gene variants in the etiology of stroke occurring in the young.

Homocysteine, folate and vitamin B(12) in puerperal cerebral venous thrombosis.

BACKGROUND AND OBJECTIVE: Hyperhomocysteinemia (hyper-Hcy) is a known risk factor for venous thrombosis, but few studies document the risk in puerperal cerebral venous thrombosis (CVT). Nutritional folate and vitamin B(12) deficiency can cause hyper-Hcy and pregnancy may contribute to this deficiency. We studied the association of plasma total homocysteine (tHcy), folate and vitamin B(12) levels with puerperal CVT through a case-control study. METHODS: Sixty women with puerperal CVT and 64 healthy puerperal controls were recruited. Plasma fasting tHcy was estimated by high pressure liquid chromatography using coulometric electrochemical detection. Vitamin B(12) and folate were measured by radioimmunoassay. Risk of puerperal CVT was estimated for each of the three variables. RESULTS: Adjusted odds ratio for the risk of puerperal CVT with hyper-Hcy (>90th percentile) was 10.8 (95% CI: 4.0-29.4; adjusted for vitamin B(12) and folate levels). Low folate and vitamin B(12) levels (<10th percentile) did not increase the risk for puerperal CVT. There was a significant inverse correlation between folate and tHcy levels (rho=-0.471, p<0.001). CONCLUSIONS: Hyperhomocysteinemia is associated with an increased risk of puerperal CVT occurring in Indian women and low folate levels contribute significantly to hyper-Hcy. Regular antenatal folate and vitamin B(12) supplementation is likely to lower puerperal tHcy levels, but its clinical benefit needs to be tested by large therapeutic trials.

Relevance of plasma levels of free homocysteine and methionine as risk predictors for ischemic stroke in the young.

BACKGROUND & AIMS: The debated vascular risk potential of total homocysteine (tHcy), due to failed clinical trials designed on B vitamin supplementation, raises many possible explanations like the higher risk potential of the deleterious, free form of homocysteine (fHcy) or, the unchecked confounding effects of B-vitamins in tHcy-based association studies. Additionally, the cardiovascular risk probability of altered status of the homocysteine precursor, methionine (tMet) could shed light on the causality of association between tHcy and cardiovascular diseases. Hence, we aimed to evaluate the risk associations of elevated plasma levels of tHcy, fHcy and low levels of tMet with premature, ischemic stroke. METHODS: We recruited 171 young, ischemic stroke patients (aged ≤45 years) and 249 age- and gender-matched healthy controls. Plasma levels of fHcy, tHcy, tMet and vitamin B6 were estimated using HPLC coupled with coulometric electrochemical detection. Plasma levels of vitamin B12 and folate were estimated by radioimmunoassay. RESULTS: Elevated fHcy (>2.9 µmol/L) was independently and strongly associated with the risk of premature, ischemic stroke (OR = 9.62, 95% CI = 3.51-26.40). On the contrary, association between premature ischemic stroke and elevated tHcy (>15.0 µmol/L) was found to attenuate when adjusted for vitamin B6 values (OR = 0.24, 95%, CI = 0.03-1.69). Interestingly, compromised B6-status (<59.2 nmol/l) was found to confer high risk of premature ischemic stroke (OR = 170.80, 95% CI = 58.22-501.06). We could not establish any significant correlation between fHcy and B-vitamin levels (P > 0.05). Low tMet (<13.86 µmol/L) was also not significantly associated with premature, ischemic stroke (OR = 2.53, 95% CI = 0.613-10.38). CONCLUSION: Our results indicate significant but not-correlated, independent associations of fHcy and vitamin B6 with risk of premature, ischemic stroke. However, the causality of these associations need prospective and large scale validations. Further, our findings highlight the crucial confounding effects of B-vitamins on risk association between tHcy and premature ischemic stroke.

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.

A genetic study of Factor V Leiden (G1691A) mutation in young ischemic strokes with large vessel disease in a South Indian population.

Factor V Leiden (FVL) has been, by far, the most investigated gene mutation, with 26 studies to date, on its role in arterial strokes. Overall, a meta-analysis of all these studies taken together showed that carriers of the Factor V Leiden allele were 1.33times more likely to develop arterial strokes when compared to controls. We subjected a highly select subset of young strokes, with large vessel infarcts, to genetic analysis for FVL mutation and compared them with matched healthy controls to look for a statistically significant association. In this prospective study, 6/120 cases (5%) and 2/120 controls (1.6%) were positive for heterozygous FVL (G1691A) mutation. The higher prevalence of FVL mutation in cases (5%) compared to controls (1.6%) did not show statistical significance with a Pearson's Chi square P value of 0.15. The Odds Ratio (OR) for risk of large vessel disease in FVL positive cases was 3.10 (95% CI of 0.61-15.7). FVL mutation (G1691A) in young Indian subjects with ischemic strokes does not seem to be significantly associated with large vessel disease.

Plasma S-adenosylhomocysteine: A potential risk marker for cerebral venous thrombosis.

BACKGROUND: Despite a plethora of studies suggesting that hyperhomocysteinemia is associated with an increased risk for arterial and venous thrombosis, there is paucity of data on the role of the S-adenosylhomocysteine (SAH), the metabolic precursor of homocysteine (Hcy) as a risk predictor for cerebral venous thrombosis (CVT). METHOD: We estimated fasting plasma concentrations of total homocysteine (tHcy), SAH and S-adenosylmethionine (SAM), in 185 CVT patients and 248 healthy controls, by reverse-phase high performance liquid chromatography coupled with coulometric electrochemical detection. RESULTS: Fasting tHcy, SAH and SAM were significantly higher in patients compared with controls. Increased tHcy and SAH concentrations were associated with 4.54-fold (95% CI, 2.74-7.53) and 35.77-fold (95% CI, 19.45-65.79) increase in risk for CVT, respectively. Receiver operating characteristic (ROC) curve analysis showed that the area under curve, sensitivity and specificity was higher for SAH compared to tHcy. Further, discriminant analysis to distinguish between tHcy and SAH showed that SAH had a significantly higher percentage classification, with lower Wilk's lambda and higher χ(2), compared to tHcy. CONCLUSION: Increased plasma SAH may be a more sensitive risk marker for CVT than plasma tHcy.

Protein Z G79A polymorphism and puerperal cerebral venous thrombosis.

Protein Z (PZ), a cofactor for PZ-dependent protease inhibitor, is known to play an important role in inhibiting the coagulation cascade. The aim of the study was to investigate whether PZ G79A polymorphism is a risk factor for puerperal cerebral venous thrombosis (CVT). A total of 71 patients with puerperal CVT and 98 healthy controls were genotyped for PZ 79GA polymorphism by polymerase chain reaction-restriction fragment length polymorphism method. In patients, the genotype distribution for GG, GA, and AA genotypes was 22.5%, 43.7%, and 33.8%, and in controls, 25.5%, 40.8%, and 33.7%, respectively. The risk associated with carrying the mutant genotype (GA and AA) versus the wild GG genotype was found to be 1.11 (95% confidence interval: 0.52-2.35; P = .909). There was no significant difference in the clinical features of the patients with and without the polymorphism. We therefore conclude that PZ G79A polymorphism is not a risk factor for puerperal CVT in Indian women.

Influence of CYP2C9 polymorphism and phenytoin co-administration on acenocoumarol dose in patients with cerebral venous thrombosis.

BACKGROUND: The study aimed at evaluating the contribution of genetic variations in the drug metabolizing enzyme, CYP2C9, and the influence of co-medication with the antiepileptic drug, phenytoin, to variability in acenocoumarol response, in patients with cerebral venous thrombosis (CVT). METHODS: 476 acenocoumarol-treated CVT patients (153 males and 323 females) were genotyped for CYP2C9*2 and CYP2C9*3 polymorphisms by PCR-RFLP method. Mean acenocoumarol dose required for achieving and maintaining a stable international normalized ratio (INR) was calculated for different genotypes. The effect of co-administration with phenytoin was determined. RESULTS: Genotype distributions of CYP2C9 were as follows: 83%CYP2C9*1/*1, 8.6%CYP2C9*1/*3, 5.9%CYP2C9*1/*2, 1.9%CYP2C9*3/*3, 0.4%CYP2C9*2/*3 and 0.2%CYP2C9*2/*2. During the initiation phase of anticoagulation the CYP2C9*2 allele was independently associated with low acenocoumarol dose requirement (Adjusted OR 5.38; 95%CI 1.65-17.49; p=0.005). Similarly, the adjusted odds ratio for requiring a low dose during the induction phase in patients bearing the CYP2C9*3 allele was 12.79 (95%CI 4.74-34.57; p<0.0001). During the maintenance phase, CYP2C9*2 and CYP2C9*3 alleles were associated with 19-fold (Adjusted OR 19.67; 95%CI 2.46-157.19; p=0.005) and 11.9-fold odds (Adjusted OR 11.98; 95%CI 2.61-55.08; p=0.001) of requiring a low dose. Clinical covariates such as age, alcohol consumption, postpartum state and oral contraceptive intake also influenced acenocoumarol dosage. Co-medication with phenytoin was associated with lower dose requirement across genotypes during the initiation phase. However, during the maintenance phase, phenytoin-treated patients of all genotypes required higher doses of acenocoumarol. CONCLUSION: This study emphasizes the fact that polymorphisms in CYP2C9 gene and co-medication with phenytoin alter the anticoagulant effect of acenocoumarol.

Plasma factor VIII in non-puerperal cerebral venous thrombosis: a prospective case-control study.

Elevated plasma factor VIII (FVIII) is increasingly recognized as an independent risk factor for thrombotic diseases. Our aim was to evaluate the association of increased plasma FVIII with cerebral venous thrombosis (CVT). Forty eight patients with non-puerperal, aseptic CVT were recruited for the study along with 50 age- and gender-matched, healthy controls. Blood samples were collected 3 months after the thrombotic event in patients. Plasma FVIII and fibrinogen levels were measured by a functional clot-based assay. Mean plasma FVIII was significantly higher in patients when compared to controls (235.40 ± 94.5 vs.121.2 ± 28.3IU/dl, p<0.001). Absence of significant elevation of fibrinogen suggested that the increase in FVIII was not due to an acute phase reaction. Elevated FVIII (>170 IU/dl) was associated with >18-fold increase in the risk for non-puerperal CVT (adjusted OR: 18.754, 95% CI 10.2-203.0, p<0.001). Non-O blood groups were more prevalent in CVT patients. Mean FVIII levels were higher in subjects with non-O blood group as compared to those with O blood group (155.16 ± 46.05 vs. 129.09 ± 40.06 IU/dl, p<0.001). Multivariate analysis with logistic regression showed that only elevated FVIII, and not blood group, was significantly associated with CVT. Our study demonstrates that elevated FVIII is an independent risk factor for non-puerperal CVT in an Indian population.

Angiotensin-converting enzyme gene insertion/deletion polymorphism and small vessel cerebral stroke in Indian population.

Background. Hypertension is an established risk factor for small-vessel cerebral stroke and the renin-angiotensin system plays an important role in the maintenance of blood pressure. We aimed at evaluating the contribution of the angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism to the risk of small-vessel stroke in south Indian population. Materials and Methods. We investigated 128 patients diagnosed with small-vessel stroke and 236 age, and gender-matched healthy controls. ACE I/D polymorphism was detected by polymerase chain reaction. Results. Hypertension was significantly more prevalent in the patient group and was associated with 6-fold increase in risk for stroke. ACE genotypes were in Hardy-Weinberg equilibrium in both patients and controls. Prevalence of DD, ID, and II genotypes in cases (34.4%, 43.7%, and 28%) did not differ significantly from controls (31.8%, 43.2%, and 25%). The polymorphism was not associated with small-vessel stroke (OR: 1.34; 95% CI: 0.52-1.55). However, diastolic blood pressure was associated with the ACE I/D genotypes in the patients. (DD; 90.2 ± 14.2> ID; 86.2 ± 11.9> II; 82.3 ± 7.8 mm Hg, P = 0.047). Conclusion. Our study showed that hypertension, but not ACE I/D polymorphism, increased the risk of small-vessel stroke.

Hyperhomocysteinemia and methylenetetrahydrofolate reductase C677T polymorphism in cerebral veno-sinus thrombosis.

There is limited data on the role of hyperhomocysteinemia as a risk factor for cerebral veno-sinus thrombosis (CVT) in Indians. We examined the association between plasma homocysteine (Hcy), methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism, and CVT in 185 patients with aseptic CVT (puerperal 80 and nonpuerperal 105) and 248 healthy controls (puerperal 67 and nonpuerperal 181). Fasting Hcy was higher in patients compared to controls (20.25 ± 5.97 vs 9.81 ± 5.19 µmol/L, P < .001) and associated with 4.54-fold (95% confidence interval [CI]: 2.74-7.53) increase in risk of CVT. Risk was higher in puerperal (odds ratio [OR]: 8.7, 95% CI: 2.73-26.91) compared to nonpuerperal CVT (OR: 3.82, 95% CI: 2.09-6.96). Plasma Hcy was higher in MTHFR 677TT compared to 677CT and 677CC genotypes (34.44 ± 32.8 vs 25.81 ± 33.3 vs 18.50 ± 23.7 µmol/L, respectively, P < .001), but the risk associated with MTHFR 677TT was insignificant (OR: 1.91, 95% CI: 0.53-7.06). We conclude that hyperhomocysteinemia is a risk marker for Indian patients with aseptic CVT. MTHFR 677TT genotype is not linked with CVT but is a determinant of plasma Hcy.

Modulation of Cardiac Autonomic Dysfunction in Ischemic Stroke following Ayurveda (Indian System of Medicine) Treatment.

Objectives. Cardiac autonomic dysfunction in stroke has implications on morbidity and mortality. Ayurveda (Indian system of medicine) describes stroke as pakshaghata. We intended to study the effect of Ayurveda therapies on the cardiac autonomic dysfunction. Methods. Fifty patients of ischemic stroke (middle cerebral artery territory) (mean age 39.26 ± 9.88 years; male 43, female 7) were recruited within one month of ictus. All patients received standard allopathic medications as advised by neurologist. In addition, patients were randomized to receive physiotherapy (Group I) or Ayurveda treatment (Group II) for 14 days. Continuous electrocardiogram and finger arterial pressure were recorded for 15 min before and after treatments and analyzed offline to obtain heart rate and blood pressure variability and baroreflex sensitivity (BRS). Results were analysed by RMANOVA. Results. Patients in Group II showed statistically significant improvement in cardiac autonomic parameters. The standard deviation of normal to normal intervals,and total and low frequency powers were significantly enhanced (F = 8.16, P = 0.007, F = 9.73, P = 0.004, F = 13.51, and P = 0.001, resp.). The BRS too increased following the treatment period (F = 10.129, P = 0.004). Conclusions. The current study is the first to report a positive modulation of cardiac autonomic activity after adjuvant Ayurveda treatment in ischemic stroke. Further long term studies are warranted.

Coagulation factor VII R353Q polymorphism and the risk of puerperal cerebral venous thrombosis.

Puerperal cerebral venous thrombosis (CVT) is a relatively common form of stroke in young women in India. The blood coagulation factor VII (FVII) R353Q polymorphism increases the risk for venous thrombosis. Our aim was to investigate the association of FVII R353Q polymorphism with the risk of puerperal CVT. A total of 100 women with puerperal CVT and 102 age-matched women without postpartum complications were investigated. FVII R353Q genotypes were identified using restriction fragment length polymorphism analysis. Our results showed that the homozygous FVII 353QQ genotype was present in 9% and 8% of patients and controls, respectively; and 42% of patients and 31.4% of controls had the heterozygous 353RQ genotype (odds ratio = 1.55, 95% confidence interval = 0.89-2.70; p = 0.243). Our findings suggest that the FVII R353Q polymorphism is not associated with increased risk for CVT occurring during the puerperal period in Indian women.

Janus kinase (JAK) 2 V617F mutation in Asian Indians with cerebral venous thrombosis and without overt myeloproliferative disorders.

It is unclear whether the somatic JAK2V617F mutation, a marker for chronic myeloproliferative disorders (MPDs), is associated with cerebral venous thrombosis (CVT) in the absence of MPD. Our aim was to determine the prevalence and association of the JAK2V617F mutation among patients with CVT and without overt MPD. We investigated 372 CVT patients without features suggestive of MPD and 383 age- and gender-matched healthy controls, for the JAK2V617F mutation. Genotyping was done by polymerase chain reaction and restriction fragment length polymorphism. The heterozygous JAK2V617F mutation was present in 22 of 372 patients (5.9%) and 2 of 383 controls (0.5%). Logistic regression analysis showed this mutation to be an independent predictor of CVT after adjusting for the conventional risk factors (adjusted odds ratio: 5.47, 95% CI: 1.06-28.27, p=0.04). The mutation was more prevalent in men (p=0.005). Patients with JAK2V617F mutation were older (p=0.036), and had higher mean hemoglobin level (p<0.0001) than those without the mutation. Smokers with the mutation had 9.45-fold increased risk of CVT compared to non-smokers without the mutation (OR: 9.45, 95% CI: 1.17-76.02, p<0.0001). We conclude that the JAK2V617F mutation could contribute to increased risk of CVT in Indians. Larger studies in other ethnic populations are warranted before considering the inclusion of the JAK2V617F gene polymorphism into the routine diagnostic workup of CVT.

Asymmetric dimethylarginine as a risk marker for early-onset ischemic stroke in Indian population.

BACKGROUND: Asymmetric dimethylarginine (ADMA), a circulating endogenous inhibitor of nitric oxide synthase, has been associated with the pathogenesis of atherosclerosis. The present study was initiated to investigate the role of ADMA as a biomarker of risk for early-onset ischemic stroke. METHODS: Plasma ADMA levels were measured in 201 ischemic stroke patients aged between 15 and 50 years and 217, age and gender-matched healthy controls, by high performance liquid chromatography using pre-column derivatization with O-phthaldialdehyde. RESULTS: Patients with ischemic stroke had significantly higher plasma ADMA compared with the controls (1.49 vs. 0.97 µmol/l, p < 0.001). After adjustment for vascular risk factors, increased ADMA was associated with stroke (OR=1.55, 95% CI 1.25-1.92, p < 0.001). Univariate analysis showed that ADMA was significantly associated with age, alcohol, smoking, hypertension, diabetes mellitus, low serum HDL-cholesterol and homocysteine. By multiple stepwise linear regression analysis, diabetes, HDL-cholesterol and homocysteine were found to be independent determinants of plasma ADMA. CONCLUSIONS: Increased plasma ADMA is associated with increased risk for ischemic stroke in the young. Diabetes mellitus, HDL-cholesterol and homocysteine are independent predictors of elevation in plasma ADMA concentration.

Association of endothelial nitric oxide synthase gene polymorphisms with early-onset ischemic stroke in South Indians.

AIM: The aim of this study was to investigate the association of T-786C, G894T and 4a/b polymorphisms in the endothelial nitric oxide synthase (eNOS) gene with early-onset ischemic stroke in South Indians. METHODS: We enrolled 177 patients diagnosed with ischemic stroke aged between 15 to 45 years and 219 age- and gender-matched healthy controls. Genotypes of eNOS T-786C, G894T and 4a/b were identified by polymerase chain reaction and restriction fragment length polymorphism. RESULTS: The allele and genotype frequencies of eNOS 4a/b, T-786C and G894T did not differ significantly in the patient group compared to controls. Logistic regression analysis indicated the 4a allele to be an independent predictor of ischemic stroke in females (dominant model: OR, 2.46; 95% CI, 1.11 to 5.43; p=0.026). Marked differences were found in the prevalence of the minor alleles of the three variants when comparing the South Indian population with the reported frequencies from Caucasians. There was also a contrast in the frequencies of 4ab and T-786C variants from other Asians. The genotypes of all three variants were found to be in Hardy-Weinberg equilibrium. There was a lack of significant linkage disequilibria among the variants, and none of the estimated haplo-types increased or decreased the risk of ischemic stroke. CONCLUSION: The eNOS intron 4a/b polymorphism can predict early-onset ischemic stroke in south Indian women.