A case-control study provides evidence of association for a common SNP rs974819 in PDGFD to coronary heart disease and suggests a sex-dependent effect

Introduction

Peden et al. have revealed a significant association between four new risk loci and coronary heart disease (CHD) in Europeans and South Asians. The goal of this study is to evaluate the contribution of these genetic loci to CHD risk in Han Chinese.

Methods

We recruited 161 CHD patients and 112 controls proved by angiography originated from Ningbo in the Eastern China, and performed a case-control association study of the four significant SNPs.

Results

Among the four tested SNPs, we found a significant association of rs974819 in PDGFD gene with CHD (allele p = 0.04; OR = 1.45, 95% CI = 1.02 - 2.08) and the allele A/G of rs974819 shows significant difference in females (allele p = 0.04; OR = 1.83, 95% CI = 1.01 - 3.31). A further meta-analysis showed that rs974819 of PDGFD gene was significantly associated with an increasing risk of CHD (OR = 1.08, 95% CI = 1.05 - 1.11) in both Europeans and South Asians including Han Chinese.

Conclusions

Our findings suggests that rs974819 of PDGFD is also a CHD risk factor in Han Chinese. In addition, it presents a sex-dependent genetic effect.     

The G894T polymorphism on endothelial nitric oxide synthase gene is associated with increased coronary heart disease among Asia population: evidence from a Meta analysis

Introduction

Growing studies have revealed the underlying association between eNOS 894 G/T (rs1799983) polymorphism and coronary heart disease (CHD) among Asia population. Results from these studies remained conflicting. We conducted this meta-analysis to estimate the overall CHD risk of eNOS 894 G/T polymorphism regarding Asia population.

Materials and methods

Up to October 2011, databases including PubMed, Embase and CNKI (China National Knowledge Infrastructure) were searched to access the relevant genetic association studies. Summary odds ratios and corresponding 95% confidence intervals (CIs) for eNOS 894 G/T polymorphism and CHD risk were estimated using fixed or random-effects models when appropriate.

Results

18 case-control studies with 2,994 cases and 3,130 controls were available for this study, including 13 studies of East-Asia descendents, 5 studies of Non East-Asian descendents. The mean T allele frequency was 0.111 in the East-Asia population and 0.147 in the Non East-Asia population, respectively. The summary OR for CHD associated with the T allele was 1.52 (95% confidence intervals (95%CI), 1.37-1.69) by random effects model. Similarly, significantly increased risks were observed in the East-Asia population (OR = 1.54; 95%CI = 1.35-1.76) and in the Non East-Asia population (OR = 1.48; 95%CI = 1.24-1.77), respectively.

Conclusions

This meta-analysis indicated that eNOS 894 G/T polymorphism may play an important role in CHD development among Asia population.     

Association of p22phox gene C242T polymorphism with coronary artery disease: A meta-analysis

Introduction

The C242T polymorphism of p22phox gene (rs4673) has been linked to the reduced coronary artery disease (CAD) risk, but results in the published literatures are controversial. A meta-analysis was performed to assess the effect of this polymorphism on the CAD risk.

Methods

A comprehensive search was conducted to identify all studies on the association of p22phox gene C242T polymorphism with CAD risk. The fixed or random effect pooled measure was selected based on the homogeneity test among studies. Heterogeneity among studies was evaluated using Q test and the I² of Higgins and Thompson. Meta-regression was used to explore the sources of between-study heterogeneity. Publication bias was estimated using modified Egger's linear regression test proposed by Harbord etal.

Results

We identified 15 published articles including 6273 CAD cases and 5045 controls. In this studied overall and non-Asian populations, we didn't found any significant association of p22phox gene C242T polymorphism with CAD in any of codominant, dominant, and recessive models. Only in Asian population, both fixed effect model (FEM) and random effect model (REM) indicated the significant protective effect both in codominant (FEM: OR = 0.771, 95%CI: 0.681-0.873; REM: OR = 0.751, 95%CI: 0.607-0.930) and dominant (FEM: OR = 0.714, 95%CI: 0.621-0.822; REM: OR = 0.694, 95%CI: 0.538-0.895) models with strong evidence for between-study heterogeneity (I² = 52.6% for codominant and I² = 56.5% for dominant), but not in recessive model. No evidence of publication bias was detected.

Conclusions

The results suggested a significant heterogeneity across ethnicities about the relationship between the T allele of p22phox gene C242T polymorphism and reduced CAD risk, with a significant protective effect only in Asian population that needs to be confirmed by further studies.     

Exploring soluble urokinase plasminogen activator receptor and its relationship with arterial stiffness in a bi-ethnic population: the SAfrEIC-study

Introduction

Elevated soluble urokinase-type plasminogen activator receptor (suPAR) indicates an inflammatory state caused by conditions such as HIV and cancer. Recently suPAR was identified as an indicator of cardiovascular disease (CVD). CVD is highly prevalent in black South Africans, but the potential role of suPAR is unknown. We investigated suPAR as a possible marker of arterial stiffness in Africans and Caucasians.

Methods

This study involved 207 Africans and 314 Caucasians (aged 20-70 yrs). C-reactive protein (CRP) and suPAR were determined in fasting blood samples. We measured blood pressure, pulse wave velocity (PWV) and Windkessel arterial compliance (Cwk).

Results

Africans displayed higher suPAR, CRP, PWV and lower Cwk (p < 0.001) compared to Caucasians. SuPAR was elevated in Africans irrespective of gender and smoking. We found strong relationships between PWV and suPAR (r = 0.27; p < 0.001) and Cwk and suPAR (r = − 0.39; p < 0.001) in the whole group, but found no independent relationship of any arterial stiffness measure and suPAR in Africans after adjustment for confounders. Caucasian men indicated a weak significant independent association between Cwk and suPAR (β = − 0.09; p = 0.028).

Conclusion

Africans had higher levels of suPAR and arterial stiffness than Caucasians (p < 0.001), but there was no independent relationship between arterial stiffness and suPAR in the Africans. It is speculated that due to the inflammatory role of suPAR, it will have stronger relationships with atherosclerosis, which has not yet manifested in this relatively young population group. SuPAR may therefore not be an ideal early marker of cardiovascular dysfunction, but may rather indicate established CVD.     

Lipoprotein lipase Ser447Ter polymorphism associated with the risk of ischemic stroke: a meta-analysis

Introduction

Previous studies suggested lipoprotein lipase (LPL) Ser447Ter and Asn291Ser polymorphisms were associated with the risk of ischemic heart disease, however, their effects on ischemic stroke were controversial. A meta-analysis was performed to assess the associations between these two LPL polymorphisms and the risk of ischemic stroke.

Methods

The electronic databases PubMed and Embase were used to identify relevant studies by two interviews independently. The pooled odds ratios (ORs) and weighted mean differences (WMD) with 95% confidence interval (CI) were estimated for the risk of ischemic stroke and the plasma lipids in various Ser447Ter genotypes respectively. A fixed or random effect model was selected for pooling data based on homogeneity test.

Results

13 studies including 4,681 ischemic stroke cases and 8,516 controls were involved in this meta-analysis. Overall, LPL Ter447 variant was associated with a significantly reduced risk for ischemic stroke (OR = 0.79, 95% CI: 0.68-0.93) both in Caucasian (OR = 0.87, 95% CI: 0.77-0.97) and East-Asian (OR = 0.65, 95% CI: 0.43-0.99), whereas no significant association of Ser291 variant was observed (OR = 1.25, 95% CI: 0.96-1.63). The Ser447Ter polymorphism may be more important in association with the decreased risk of atherosclerotic stroke (OR = 0.44, 95% CI: 0.32-0.62) which derived from significantly increased high density lipoprotein cholesterol, decreased triglyceride and total cholesterol in Ter447 carriers compared with non-carriers.

Conclusions

This meta-analysis indicated that LPL Ser447Ter polymorphism was associated with a significant reduction in the risk of ischemic stroke, especially atherosclerotic stroke subtype in both Caucasian and East-Asian.     

The prevalence of dental anxiety across previous distressing experiences

Aims

To compare the prevalence of high dental anxiety across a variety of past distressing experiences with a previously reported Dutch sample.

Method

University students from the UK (N = 1024) completed an online survey containing; the Modified Dental Anxiety Scale, and the Level of Exposure-Dental Experiences Questionnaire (LOE-DEQ). Adjusted odds ratios (OR) were calculated to assess the association of self-reported distressing experiences and dental anxiety.

Results

The percentage of respondents with high dental anxiety (HDA) (total MDAS score ≥ 19) was 11.2%. Significant prevalence of HDA across several distressing experiences was shown in both UK and Dutch samples notably: extreme helplessness during dental treatment, lack of understanding of the dentist and extreme embarrassment during dental treatment. There were little or no effects of non-dental trauma, with the exception of sexual abuse in the UK sample.

Conclusions

Trauma from various past experiences may be implicated in an increased risk of high dental anxiety.     

The impact of co-morbid conditions on family history of venous thromboembolism in Whites and Blacks

Introduction

Our objectives were to compare the magnitude of family history as a risk factor for venous thromboembolism (VTE) risk between Blacks and Whites, and to assess the impact of co-morbid conditions on familial risk for VTE.

Materials and methods

We used data from the Genetic Attributes Thrombosis Epidemiology (GATE) study, a matched case-control study which enrolled Blacks and Whites aged 18-70 years in Atlanta, Georgia. A total of 1,094 case patients with a deep vein thrombosis (DVT) or pulmonary embolism (PE) and 1,264 control patients were interviewed about their family history.

Results

Family history of VTE was a statistically significant risk factor for VTE among Blacks (odds ratio (OR) = 2.9, 95% confidence interval (CI) 2.0-4.1; P value < 0.0001) and among Whites (OR = 2.7, 95% CI 1.9-3.7; P value < 0.0001); among Blacks and Whites who were obese or had hypertension; among Blacks who had diabetes mellitus or cancer; as well as among males and females, and across all age categories. Family history of VTE increased the risk of VTE among Blacks with cancer by about 6-fold, whereas among Blacks without cancer the increased risk due to a positive family history was about 3-fold; a 2-fold relative difference. In addition, family history was a risk factor for VTE among case patients with DVT only or with PE only. The effect of family history generally was stronger among those with recurrent episodes of VTE compared with a first episode of VTE. For example, family history of any VTE was a strong risk factor among Black females with recurrent VTE compared with Black females with first VTE (OR = 3.9, 95% CI 2.0-7.5; P value < 0.0001).

Conclusion

Our study indicated that the adjusted attributable fraction for VTE was 16.9% among Blacks vs. 18.3% among Whites, and certain co-morbid conditions could further increase the risk of VTE associated with a positive family history of VTE.     

Association of the ZNF804A gene polymorphism rs1344706 with white matter density changes in Chinese schizophrenia

Background

ZNF804A gene polymorphism rs1344706, the first genetic risk variant to achieve genome wide significance for schizophrenia, has been linked to neural functional connectivity. Dysconnectivity of WM may be the primary pathological mechanism of schizophrenia. Association of this variant with regional WM density has not been investigated in schizophrenic patients.

Methods

69 healthy controls and 80 patients with schizophrenia underwent genotyping of rs1344706 SNPs, and were examined for WM density (T1-weighted MRI). The association of rs1344706 with WM changes in schizophrenia patients and healthy controls was analyzed using a full-factorial 2 × 2 analysis of variance.

Results

1. There was an interaction on WM density in the left prefrontal lobe between the rs1344706 genotype and schizophrenic diagnosis, where the risk T allele carriers presented higher WM density in the schizophrenia patients and lower WM density in healthy controls in comparison with the non-risk allele carriers.2. The risk allele was associated with an increased WM density of the bilateral hippocampus in both the patients and the healthy group.

Limitation

The influence of antipsychotics to the white matter in schizophrenic patients was not fully eliminated.

Conclusions

The ZNF804A variant may confer risk for schizophrenia by exerting its effects on the WM in the left prefrontal lobe together with other risk factors for schizophrenia.     

Influence of Klotho genotypes on plasma NO(x) levels in South Indian population

Introduction

Despite experimental evidences of the influence of the aging suppressor gene Klotho, on the modulation of endothelial nitric oxide synthase (eNOS) activity and nitric oxide (NO) production, the contribution of its variants to the phenotypic variance of plasma nitrite and nitrate (NO_x) has not been addressed to date. In the present study, we aimed to determine the influence of two exonic variants, KL-VS and C1818T of Klotho, on circulating NO_x levels in South Indian population.

Materials and Methods

We genotyped the two Klotho KL-VS and C1818T variants in 429 healthy South Indians and measured their plasma NO_x concentrations by the Griess method.

Results

Genotype frequencies were compared in subjects with low and high NO_x levels. An age-specific association of the Klotho C1818T variant was found with plasma NO_x levels in subjects aged > 40 years (p = 0.027); the CC homozygotes were more prevalent in the low compared to the high plasma NO_x group. However, the variant was not associated with plasma NO_x levels in subjects aged ≤ 40 years (p = 0.799). The KL-VS variant did not have any influence on plasma NO_x status (p = 0.260).

Conclusions

Our results suggest that the effect of Klotho C1818T variant on levels of plasma NO_x becomes pronounced with age probably implying the adaptive capability of Klotho alleles to meet the age-related increasing physiological load.     

Hopelessness, a potential endophenotpye for suicidal behavior, is influenced by TPH2 gene variants

Objectives

Hopelessness is one of the strongest risk factors for suicidal behavior but relevant genetic studies are poorly available. Tryptophan hydroxylase (TPH) is widely considered to be a good candidate for genetic association studies on depression and suicide, however, investigations on these complex, multifactorial phenotypes have resulted in conflicting data. We hypothesized that hopelessness could be a mediating phenotype between TPH2 gene, depression and suicidal behavior.

Methods

Depressive phenotype and suicidal risk were investigated of 760 individuals from general population by Zung Self Rating Depression Scale (ZDS), Beck's Hopelessness Scale (BHS) and a detailed background questionnaire. All participants' DNA samples were genotyped for 7 tag SNPs in TPH2 gene. Generalized linear models were performed for single marker association studies and p-values were corrected by Bonferroni criteria. In haplotype analyses score tests were used and permutated p-values were computed.

Results

Four SNPs of TPH2 gene showed association with hopelessness but only rs6582078 had a significant effect on the BHS scores after Bonferroni's correction; GG individuals had significantly higher BHS scores, while GT and TT had intermediate and lower BHS scores respectively (p = 0.0047). Compared with other genotypes, homozygous GG individuals also had almost three times greater estimated suicidal risk, as did carriers of the AA genotype of rs6582078 (OR = 2.87; p = 0.005) and also of rs1352250 (OR = 2.86; p = 0.006). A risk and a protective haplotype of TPH2 gene were also identified in association with hopelessness. ZDS scores have not shown any association with TPH2 gene.

Conclusions

We found that hopelessness, with its allied increased suicidal risk was strongly associated with TPH2 gene variants in multiple tests. These findings suggest that TPH2 gene confers risk for suicidal behavior while hopelessness can be a potential endophenotype for suicidal vulnerability.     

Effects of haloperidol and risperidone on cerebrohemodynamics in drug-naive schizophrenic patients

Background

Use of antipsychotics may be associated with cerebrovascular adverse events in psychotic patients. In this study, the effects of haloperidol and risperidone on the cerebral hemodynamics and the possible relationships between antipsychotics and cerebrovascular risks tendency were evaluated by Transcranial Doppler ultrasonography (TCD).

Methods

Twenty drug-na?¨ve schizophrenic patients and 20 normal control subjects were included. The patients were divided into haloperidol- and risperidone-treated groups and received treatment for 8 weeks double-blindly. The subjects’ cerebral blood flow mean velocities (MV) and pulsatility index (PI) were measured weekly by TCD. The Positive and Negative Syndrome Scale for schizophrenia (PANSS) was used to assess the patients’ psychopathological symptoms.

Results

Increased MV and decreased PI were found significantly in drug-na?¨ve schizophrenic patients than normal subjects before treatment (p < 0.01). The decreased PI could be normalized after 8 weeks of antipsychotic treatment, while the increased MV could not. Treatment with haloperidol could significantly increase the PI than the treatment with risperidone (p < 0.01) throughout the treatment course. The PANSS scores of both groups were significantly improved (p < 0.05) at the endpoints of treatment.

Conclusions

Our findings indicate that haloperidol may affect the cerebral hemodynamics in drug-na?¨ve schizophrenics more prominently than that of risperidone via TCD monitoring.     

Anterior cingulate proton spectroscopy glutamate levels differ as a function of smoking cessation outcome

Background

Cigarette smoking is the leading preventable cause of death. Unfortunately, the majority of smokers who attempt to quit smoking relapse within weeks. Abnormal dorsal anterior cingulate cortex (dACC) function may contribute to tobacco smoking relapse vulnerability. Growing evidence suggests that glutamate neurotransmission is involved in mediating nicotine dependence. We hypothesized that prior to a cessation attempt, dACC glutamate levels would be lower in relapse vulnerable smokers.

Methods

Proton magnetic resonance spectra (MRS) were obtained from dACC and a control region, the parieto-occipital cortex (POC), using two-dimensional J-resolved MRS at 4 T and analyzed using LCModel. Nine nicotine-dependent women were scanned prior to making a quit attempt. Subjects then were divided into two groups; those able to maintain subsequent abstinence aided by nicotine replacement therapy (NRT) and those who slipped while on NRT (smoked any part of a cigarette after attaining at least 24 h of abstinence).

Results

Slip subjects exhibited significantly reduced dACC MRS glutamate (Glu/Cr) levels (p < 0.03) compared to abstinent subjects. This effect was not observed in the POC control region.

Conclusions

Our preliminary findings suggest that dACC Glu levels as measured with MRS may help identify and/or be a biomarker for relapse vulnerable smokers. Future research following up on these findings may help clarify the role of dACC Glu in smoking dependence that may lead to new treatment strategies.     

Association of elevated NTproBNP with recurrent thromboembolic events after acute pulmonary embolism

Introduction

N-Terminal Pro-Brain Natriuretic Peptide (NTproBNP) is a predictor of adverse short-term clinical outcomes in patients with acute pulmonary embolism (APE), but its long-term prognostic value remains largely undefined. The aim of this study was to assess the value of plasma NTproBNP with regard to recurrent venous thromboembolism (VTE).

Materials and Methods

NTproBNP levels were measured in 224 consecutive patients with the first episode of acute pulmonary embolism occurring from January 2005 through October 2010. Patients were categorized into two groups by NTproBNP reference range. Follow-ups were performed at 3, 6, and 12 months and yearly thereafter. The primary end point was symptomatic, recurrent fatal or nonfatal VTE.

Results

NTproBNP was elevated in 158 (70.5%) patients and not elevated in 66 (29.5%) patients. After a mean follow-up period of 31.0 ± 19.4 months, patients with elevated NTproBNP showed an increased risk of recurrent VTE (20 patients, 12.7%) compared to those without elevated NTproBNP (only 1 patient, 1.5%) (P = 0.009). Of the 7 deaths related to pulmonary embolism, 6 occurred in patients with elevated NTproBNP compared to patients with normal NTproBNP (1 of 7 deaths). In a multivariate analysis stratified by oral anticoagulant treatment duration, elevated NTproBNP was an independent predictor of recurrent VTE (hazard ratio, 9.32; P = 0.02).

Conclusions

Elevated NTproBNP is associated with recurrent VTE in acute pulmonary embolism patients.     

Joint effect of self-reported sleep problems and three components of the metabolic syndrome on risk of coronary heart disease

Objective

This study explored the joint effect of two epidemics, sleep problems and metabolic syndrome (MetS), on the risk of coronary heart disease (CHD).

Methods

The study group is part of the Finnish middle-aged men who participated in the first screening for the Helsinki Heart Study (HHS) in 1981-1982. At that time, three components of MetS were measured: body mass index, HDL cholesterol, and blood pressure. Later, in 1986-1988, they were given a psychosocial questionnaire including items on sleep problems. Of the respondents, 2753 formed our study group and were followed up using population-based registers until 1995. The relative risks (RR) of CHD were estimated using Cox's regression models.

Results

When several sleep problems were present simultaneously, some increased CHD risk was observed. However, when considered jointly with MetS, insomnia or daytime fatigue approximately doubled the CHD risk and the presence of insufficient sleep more than tripled the risk. Among those who had MetS only, the RR was 2.55, and among those with both insufficient sleep and MetS the RR was 9.36 (95% confidence interval: 4.60-19.04; P for interaction 0.09) when compared to those with no insufficient sleep and no components of MetS.

Conclusion

The interaction occurred when all three measured MetS components were present, suggesting that co-occurrence of these two epidemics may predict growing public health problems.     

Comparison of a direct Factor Xa inhibitor, edoxaban, with dalteparin and ximelagatran: A randomised controlled trial in healthy elderly adults

Introduction

Edoxaban (the free base of DU-176b) is a new, oral direct Factor Xa inhibitor. This is the first study to compare the hemostatic response to edoxaban, ximelagatran, and dalteparin in healthy, elderly adults.

Materials and Methods

In this open-label, active-controlled clinical trial, 40 adults (65-75 years), were randomised to: oral edoxaban (60 mg, twice-daily, 7 doses), subcutaneous dalteparin (5000 IU, once-daily, 4 doses), oral ximelagatran (24 mg, twice-daily, 7 doses) or no drug. Blood samples were taken before, and 1.5, 4, 12, 24, 72, 84, 96, 108, 120, and 144 hours after, the first dose. The primary outcomes were changes in thrombin-antithrombin complex, prothrombin fragment 1 + 2 and D-dimer, and adverse events. Additional biomarkers of coagulation, and endothelial cell and platelet activation were compared (ANOVA).

Results

All subjects completed the study. Inhibition of thrombin generation lag time, peak, and constant velocity index were significantly greater, and extended for a longer period of time, following edoxaban administration, compared with dalteparin. We found that the traditional assay for anti-FXa activity was not appropriate for the new anticoagulants. Biomarker changes following edoxaban administration (including prolongation of prothrombin time) reflected inhibition of Factor Xa; there was no effect on platelet, tissue factor or endothelial activation. There were no clinically significant changes in primary outcomes. No serious adverse events were reported.

Conclusion

Oral administration of edoxaban resulted in effective Factor Xa and TG inhibition, and was well-tolerated. Studies are needed to confirm edoxaban (60 mg daily) use in clinical practice.

Sponsorship

Daiichi Sankyo Pharma Development.     

A pilot study of antipsychotic prescribing decisions for acutely-Ill hospitalized patients

Background

Evidence on antipsychotic prescribing decisions is limited. This pilot study quantified factors considered in choosing an antipsychotic and evaluated the influence of metabolic status on treatment decisions.

Methods

Prescribing decisions by 4 psychiatrists were examined based on 80 adult patients initiated on antipsychotic medication diagnosed with schizophrenia, schizoaffective disorder or bipolar disorder by DSM-IV criteria, who were admitted to an acute inpatient psychiatric program of an urban Veterans Affairs Medical Center. The primary analysis examined the association between antipsychotic treatment choice and predictions of symptom control and metabolic risk. Secondary analyses included comparison of the chosen and next best treatments in predicted symptom control and metabolic risk, the frequency of reasons cited for drug choice, and the association between treatment choice and patients' baseline metabolic parameters. Mean differences and odds-ratios (OR) with 95% confidence intervals were used to compare relationships between treatment choice, ratings of risk and metabolic data.

Results

Antipsychotic choice correlated significantly with ratings of predicted symptom control (OR = .92, p = 0.02) and metabolic risk (OR = .88, p = 0.01). Mean differences between the chosen and next best drugs were significant but small in predicted symptom control (F = 2.81, df = 3, 76; p < 0.05) compared with larger differences in anticipated metabolic risk (F = 14.80, df = 3, 76; p = 0.0001). Nevertheless, among 24 identified reasons influencing drug selection, anticipated metabolic risk of chosen antipsychotics was cited less often than efficacy measures. In contrast to psychiatrists' expectations of metabolic risk with selected treatments, we found that patients' actual baseline BMI, fasting glucose, blood pressure, and Framingham risk levels did not necessarily predict antipsychotic treatment choice independent of other factors.

Conclusion

In the context of an acute psychiatric hospitalization, pilot data suggest that predictions of symptom control and metabolic risk correlated significantly with antipsychotic choice, but study psychiatrists were willing to assume relative degrees of metabolic risk in favor of effective symptom control. However, prescribing decisions were influenced by numerous patient and treatment factors. These findings support the potential utility of the ATCQ questionnaire in quantifying antipsychotic prescribing decisions. Further validation studies of the ATCQ questionnaire could enhance translation of research findings and application of treatment guidelines.     

Low-molecular-weight heparin inhibition in classical complement activaton pathway during pregnancy

Introduction

Low-molecular-weight heparin is used clinically for the prevention of pregnancy complications associated with prothrombotic disorders, particularly anti-phospholipid syndrome. Nevertheless, recent studies have suggested that heparin may exert direct effects on the placental trophoblast, independently of its anticoagulant activity. In addition, heparin prevents complement activation in vivo and protects mice from pregnancy complications.

Materials and Methods

The inhibition of the classical complement activation pathway by heparin was analyzed by means of in vitro assays and in pregnant women receiving prophylaxis with therapeutic doses (40 mg/day) of subcutaneous low molecular weight heparin by haemolysis of antibody-sensitized sheep erythrocytes (CH₅₀ assay).

Results

The specific interaction between low-molecular-weight heparin and the C1q subunit of the C1 complex of the complement cascade allowed the isolation of a small subpopulation of heparin ( 8.03 ± 1.20 μg %), with an anti-activated factor X activity more than four times greater than the starting material. This subpopulation could be responsible for the in vitro inhibition of the classical complement activation pathway evaluated by the total haemolysis of antibody-sensitized sheep erythrocytes. About 60 µg/ml of low molecular weight heparin was needed to achieve 50% of haemolysis. The detection of the classical complement pathway inhibition in pregnant women treated with heparin required a first activation with aggregated human IgG.

Conclusions

We concluded that the interaction between low-molecular-weight heparin and C1q could be relevant not only in the complement-dependent, but also in the complement-independent inflammation mechanisms responsible for the prevention of pregnancy loss.     

Incidence and predictive factors of symptomatic thrombosis related to peripherally inserted central catheters in chemotherapy patients

Introduction

The incidence of symptomatic catheter-related deep vein thrombosis (DVT) in cancer patients remains unclear and there is a lack of reliable data on the risk factors of PICC-related DVT.

Materials and Methods

We performed a retrospective cohort study of consecutive cancer patients who received an ultrasound guided PICC line for the administration of chemotherapy. Univariable and multivariable logistic regression analyses were performed to identify risk factors for symptomatic PICC-related DVT.

Results

In total, 340 cancer patients obtained PICC lines for the administration of chemotherapy. Of these patients, 19 (5.6%; 95% CI: 3.6-8.6) developed symptomatic PICC-related DVT. Factors previously associated with catheter-related DVT, including side of catheter placement, lumen size, tip location, need for repositioning, and number of insertion attempts, were not significant determinants in our analysis. Patients with diabetes were three times more likely to develop PICC-related DVT (OR 3.0, p = 0.039), while the presence of COPD and metastatic cancer also increased the odds (OR 3.3, p = 0.078 and OR 2.3, p = 0.083 respectively). Diabetes remained a significant risk factor after adjustment for effect of metastases and COPD (OR 3.175, p = 0.039). Further, the presence of metastases was a significant predictor (OR 3.34, p = 0.024) in our multivariable model.

Conclusions

Symptomatic PICC-related DVT are frequent in cancer patients receiving chemotherapy. Previously described factors associated with catheter-related thrombosis were not predictive of PICC-related DVT in our study. Diabetes, advanced disease and COPD appear to increase the risk of developing PICC-related DVT in chemotherapy patients.     

Thrombophilic screening in young patients (< 40 years) with idiopathic ischemic stroke: a controlled study

Introduction

Despite extensive clinical and laboratory investigations, the etiology of ischemic stroke remains unknown in approximately one third of patients.

Materials and Methods

Thirty-four consecutive patients less than 40 years old (Males 13, Females 21, mean age 26.6 years, range 2-39) with documented ischemic stroke underwent, one year after the acute event, laboratory evaluation of antithrombin, protein C, free and total protein S, activated protein C resistance, fibrinogen, factor VII:C, homocysteine levels and antiphospholipid antibodies (APA). Moreover, prevalence of F5 R506Q, F2 G2021A and homozygosis for thermolabile variant C677T of the methylenetetrahydrofolate reductase (MTHFR) were also evaluated and compared to the results obtained in 120 normal controls.

Results

Antithrombin and protein C levels resulted normal in all cases. One patient (2.9%) showed free protein S deficiency and 3 patients (8.8%) had activated protein C resistance. Homocysteine levels above 15 μmol/L were found in one patient (2.9%). APA were found in 21 patients (61.7%) and in only 2 out of 120 (1.66%) controls (OR = 95.31; 95% C.I.: 18.22-667.81). The multivariate analysis selected that the presence of APA was significantly associated with an increased risk of stroke (OR = 156.60; 95% C.I.: 25.99-943.47) in this cohort of patients. The combination between APA and cardiovascular risk factors determined a risk of 29-fold (OR = 29.31; 95% CI: 3.28-261.69).

Discussion

Our data suggest that the presence of APA is associated with an increased risk of idiopathic ischemic stroke in young patients. Furthermore, also the combination of APA and cardiovascular risk factors is significantly associated with development of idiopathic ischemic stroke.     

Impact of P2Y12-ADP receptor polymorphism on the efficacy of clopidogrel dose-adjustment according to platelet reactivity monitoring in coronary artery disease patients

Introduction

High on-treatment platelet reactivity (HTPR) after clopidogrel loading dose (LD) is associated with a high risk of thrombotic events after percutaneous coronary intervention(PCI). We have demonstrated that HTPR could be overcome in the majority of cases using LD adjustment resulting in an improved clinical outcome. However this strategy failed in nearly 10% of patients with HTPR. We aimed to determine if P2Y12-ADP receptor polymorphisms were associated with failed dose adjustment.

Materiel and method

Forty-three patients undergoing PCI were included in this prospective study. A VASP index ≥ 50% after a 600 mg LD of clopidogrel defined HTPR. Dose adjustment was performed according to PR monitoring to reach a VASP index < 50%. Genetic polymorphism of the P2Y12-ADP receptor was determined by direct sequencing.

Results

Patients with successful dose-adjustment (SDA) (n = 33) and failed (FDA) (n = 10) dose-adjustment groups were compared. The 2 groups were similar in terms of cardiovascular risk factors including diabetes mellitus (SDA vs FDA: 42 vs 20%; p = 0.3). The prevalence of the H2 allele of the P2Y12-ADP receptor was also similar between the 2 groups (p = 0.3). The H2 allele was found in 6 patients which are all included in the SDA group. After the first 600 mg loading dose of clopidogrel, patients carrying at least one H2 allele had similar VASP index compared to those carrying two copies of the wild type allele (H1) (SDA vs FDA: 44.9 ± 14.9 vs 43.5 ± 10%; p = 0.8).

Conclusion

The present study suggests that the H2 allele of the P2Y12-ADP receptor is not involved in clopidogrel failed dose adjustment according to platelet reactivity monitoring.