Relationship between proprotein convertase subtilisin/kexin type 9 (PCSK9) and thrombotic events in primary antiphospholipid syndrome. The multicenter ATHERO-APS study

Background

The proprotein convertase subtilisin/kexin type 9 (PCSK9) is a novel cardiovascular risk factor. Levels of PCSK9 in thrombotic primary antiphospholipid syndrome (PAPS) have never been investigated.

Methods

Cross sectional comparison of baseline characteristics of 91 PAPS patients enrolled in the multicenter ATHERO-APS cohort study. PCSK9 levels were categorized into tertiles and the association with arterial and recurrent thrombosis were assessed by univariable and multivariable regression analysis.

Results

Median age was 51 years and 71.4% (n=65) were women. Overall, 33% (n=30) experienced an arterial event while 31% (n=28) had recurrent thrombotic events. Median PCSK9 levels were 1243 (1100–1650) pg/ml. Patients in the third PCSK9 tertile (>1458 pg/ml) showed a higher prevalence of dyslipidemia, lupus anticoagulant positivity and a history of previous arterial and recurrent thrombosis than patients in the first and second tertile. PCSK9 levels were higher in arterial than venous thrombosis (1502 vs. 1180 pg/ml, p=0.002), and in patients with recurrent vs isolated thrombosis (1680 vs. 1150 pg/m, p<0.001). High plasma PCSK9 levels were associated with a 4-fold increase risk for arterial events and with a 10-fold increase risk for recurrent thrombosis after adjustment for confounding factors.

Conclusion

These preliminary data suggest that in PAPS, PCSK9 levels are associated with arterial and recurrent thrombosis. Its role as a possible therapeutic target in PAPS needs further studies.

Funding Acknowledgement

Type of funding sources: None.

Bleeding and thrombotic events in patients with atrial fibrillation and cancer: a systematic review and meta-regression analysis

Background

Atrial fibrillation (AF) and cancer are frequently coexisting in elderly patients. Pooled metanalytic data on the impact of cancer on outcomes in AF patients are lacking.

Purpose

We want to investigate the impact of cancer in patients with AF, particularly in relation to the incidence of bleeding and ischemic events

Methods

Systematic review and meta-regression analysis of clinical studies retrieved from Medline (PubMed) and Cochrane (CENTRAL) databases according to PRISMA guidelines. Safety endpoints included any, major, gastrointestinal (GI) bleeding and intracranial haemorrhage (ICH). Efficacy endpoints included myocardial infarction (MI), ischemic stroke/systemic embolism (IS/SE), cardiovascular (CV) and all-cause death.

Results

15 studies were included in the metanalysis: 4 prospective, 3 randomized clinical trials and 8 retrospective studies with 2,868,010 AF patients, of whom 479,571 (16.7%) had cancer. The pooled HR for cancer was 1.43 (95% CI 1.42–1.44) for any bleeding, 1.27 (95% CI 1.26–1.29) for major bleeding, 1.17 (95% CI 1.14–1.19) for GI bleeding, and 1.07 (95% CI 1.04–1.11) for ICH. The risk of major bleeding increased with the proportion of breast cancer. Cancer increased the risk of all-cause death (HR 2.00, 95% CI 1.99–2.02) whereas no association with MI (HR 0.97, 95% CI 0.94–1.01) and CV death (HR 1.01, 95% CI 0.99–1.03) was found. Patients with AF and cancer were less likely to suffer from IS/SE (HR 0.91, 95% CI 0.89–0.94).

Conclusion

The presence of cancer modifies the clinical history of AF patients, mainly increasing the risk of bleeding. Further analyses according to the type and stage of cancer is necessary to better stratify bleeding risk in these patients.

Funding Acknowledgement

Type of funding sources: None.

Expression of pyrethroid metabolizing P450 enzymes characterizes highly resistant Anopheles vector species targeted by successful deployment of PBO-treated bednets in Tanzania

Long lasting insecticidal nets (LLINs) are a proven tool to reduce malaria transmission, but in Africa efficacy is being reduced by pyrethroid resistance in the major vectors. A previous study that was conducted in Muleba district, Tanzania indicated possible involvement of cytochrome P450 monooxygenases in a pyrethroid resistance in An. gambiae population where pre-exposure to piperonyl butoxide (PBO) followed by permethrin exposure in CDC bottle bioassays led to partial restoration of susceptibility. PBO is a synergist that can block pyrethroid-metabolizing enzymes in a mosquito. Insecticide resistance profiles and underlying mechanisms were investigated in Anopheles gambiae and An. funestus from Muleba during a cluster randomized trial. Diagnostic dose bioassays using permethrin, together with intensity assays, suggest pyrethroid resistance that is both strong and very common, but not extreme. Transcriptomic analysis found multiple P450 genes over expressed including CYP6M2, CYP6Z3, CYP6P3, CYP6P4, CYP6AA1 and CYP9K1 in An. gambiae and CYP6N1, CYP6M7, CYP6M1 and CYP6Z1 in An. funestus. Indeed, very similar suites of P450 enzymes commonly associated with resistant populations elsewhere in Africa were detected as over expressed suggesting a convergence of mechanisms across Sub-Saharan African malaria vectors. The findings give insight into factors that may correlate with pyrethroid PBO LLIN success, broadly supporting model predictions, but revision to guidelines previously issued by the World Health Organization is warranted.

Invasive Malaria Vector Anopheles stephensi Mosquitoes in Sudan, 2016-2018

Anopheles stephensi mosquitoes are urban malaria vectors in Asia that have recently invaded the Horn of Africa. We detected emergence of An. stephensi mosquitoes in 2 noncontiguous states of eastern Sudan. Results of mitochondrial DNA sequencing suggest the possibility of distinct invasions, potentially from a neighboring country.

Prevalence of heart failure with preserved ejection fraction in antiphospholipid antibodies syndrome. The multicenter ATHERO-APS study

Background

The prevalence of heart failure with preserved ejection fraction (HFpEF) in patients with antiphospholipid syndrome (APS) is unknown.

Methods

Prospective multicenter cohort study including 125 patients: 91 primary APS (PAPS), 18 APS-SLE, and 16 carriers. HFpEF was diagnosed according to the 2019 European Society of Cardiology criteria: patients with ≥5 points among major and minor functional and morphological criteria including NT-ProBNP >220 pg/ml, left atrial (LA) enlargement, increased left ventricular filling pressure.

Results

Overall, 18 (14.4%) patients were diagnosed with HFpEF; this prevalence increased from 6.3% in carriers to 13.2% in PAPS and 27.8% in APS-SLE (Figure). Patients with HFpEF were older and with a higher prevalence of hypertension and previous arterial events. At logistic regression analysis, age, arterial hypertension, anticardiolipin antibodies IgG >40 GPL (odds ratio [OR] 3.43, 95% Confidence Interval [CI] 1.09–10.77, p=0.035), anti β-2-glycoprotein-I IgG >40 GPL (OR 5.28, 1.53–18.27, p=0.009), lupus anticoagulants DRVVT >1.25 (OR 5.20, 95% CI 1.10–24.68, p=0.038), (OR 3.56, 95% CI 1.11–11.47, p=0.033) and triple positivity (OR 3.56, 95% CI 1.11–11.47, p=0.033) were associated with HFpEF after adjustment for age and sex.

Discussion

HFpEF has a clinically relevant prevalence in patients with APS. The role of antiphospholipid antibodies in the pathogenesis and prognosis of HFpEF needs to be investigated.

Funding Acknowledgement

Type of funding sources: None.

Peripheral arterial disease has a strong impact on cardiovascular outcome in patients with acute coronary syndromes: from the START Antiplatelet registry

BACKGROUND

Peripheral arterial disease (PAD) was reported to increase the risk of new cardiovascular events in patients with acute coronary syndromes (ACS). However, most of the evidence comes from randomized clinical trials. We aimed to assess the impact of PAD on cardiovascular outcome and treatment decisions in ACS patients in a current real-life setting.

METHODS

START-ANTIPLATELET is a multicenter registry enrolling ACS patient. Baseline clinical characteristics and treatment at discharge were recorded and follow-up was repeated at 6-months and 1-year. PAD was defined as intermittent claudication and/or previous revascularization.

RESULTS

Among 1442 patients enrolled, 103 (7.1%) had PAD. PAD patients were older (71.8 ± 10.6vs66.2 ± 12.6 yrs., p < 0.0001), more frequently hypertensive (90.3vs68.6%, p< 0.0001), hypercholesterolemic (66vs52%, p= 0.037), diabetic (51.5vs24%, p= 0.0001), obese (28.2vs19.3%, p= 0.029) and with previous TIA (7.8vs2.8%, p= 0.005) or stroke (11.7vs3.1%, p< 0.0001). Clinical presentation and acute treatment were similar in non-PAD and PAD patients, but the latter were discharged significantly less frequently on dual antiplatelet therapy (DAPT) (68.9vs85%, p= 0.005). After a median follow-up time of 11.1 months, major cardio/cerebrovascular event-free survival [MACCE, including cardiovascular death, MI, TIA and stroke, target-vessel revascularization (TVR) and major arterial ischemic events] was significantly shorter (9.0vs11.2 months, p= 0.02; HR 3.2, 2.4-8.4) in PAD patients and net adverse cardiovascular events (NACE = MACCE plus major hemorrhages) were significantly more frequent (19.1%vs10.5%, p = 0.049).

CONCLUSIONS

PAD identifies a subgroup of ACS patients at significantly increased cardiovascular risk, but these patients tend to be undertreated. Patients admitted for ACS should be screened for PAD and optimal medical therapy at discharge should be implemented.

The Atrial fibrillation Better Care (ABC) pathway is associated to a lower incidence of cardiac complications in patients with atrial fibrillation: a report from the ATHERO-AF study

Background

The integrated management of atrial fibrillation (AF) patients according to the Atrial fibrillation Better Care (ABC, A, Avoid stroke with anticoagulation; B, better symptom management; C, Cardiovascular and comorbidity risk management) pathway has associated with a reduced incidence of thromboembolic events and mortality. However, whether this approach also results in a lower rate of cardiac complications is unknown.

Purpose

To investigate the rate of major adverse cardiovascular events (MACE) in AF patients according to compliance with the ABC pathway.

Methods

This prospective single-center cohort study included 1157 patients with nonvalvular AF from the ATHERO-AF study. The A, B, and C groups were defined as follows: “A” by a Time in Therapeutic Range ≥70% in vitamin K antagonists-treated patients or appropriate dose for patients on direct oral anticoagulants; “B” by a European Heart Rhythm Association (EHRA) symptom scale I-II (vs. III-IV), and “C” as optimized cardiovascular comorbidity management (i.e. use of ACE inhibitors in heart failure patients, blood pressure &lt;140/90, use of statins and beta blockers in patients with prior ischemic heart disease). The primary end point was a composite of MACE including fatal/non-fatal myocardial infarction, coronary revascularization and cardiovascular death (progressive heart failure, sudden cardiac death and procedure-related death).

Results

Overall, 458 (39.6%) patients were optimally managed according to the ABC (ABC-compliant group), while the remaining 729 patients presented at least one uncontrolled component (ABC non-compliant group). During a mean follow up of 35 months, (2688 patient-years), 64 MACE were recorded 2.38%/year. Kaplan Meier curve analysis showed a significant higher rate of MACE in ABC non-compliant group compared to the ABC-compliant (54 and 10 MACE in each group, respectively, log-rank test p=0.006, figure). The risk of MACE increased by the number of uncontrolled ABC components: Hazard ratio HR) for 1 component 1.697, 95% Confidence Interval 95% CI 0.814–3.537, p=0.158; HR for 2 components 4.157, 95% CI 1.994–8.665, p&lt;0.001); HR for 3 components 5.100, 95% CI 1.596–16.295, p=0.006.

ABC non-compliant group remained associated with an increased risk of MACE using Cox proportional hazard regression analysis (HR 2.175, 95% CI 1.098–4.309, p=0.026) after adjustment for CHA2DS2VASc score, antiplatelet drugs and digoxin use.

Conclusion

The majority of AF patients is not currently optimally managed. An integrated care ABC approach is associated with a reduced risk of MACE in the AF population.

Figure 1. Kaplan-Meier curves

Funding Acknowledgement

Type of funding source: None

Ischemic and bleeding risk stratification in diabetic patients after acute coronary syndrome based on insulin requirement

Background

Diabetes is a known risk factor for a first or recurrent cardiovascular event, however, its association with an increased risk of bleeding is controversial. To date, no study has explored the prognostic weight of insulin therapy in the setting of ACS.

Purpose

To investigate the differential role of insulin versus no insulin therapy on ischemic and bleeding risks in patients with diabetes and ACS.

Methods

START-ANTIPLATELET is a prospective, real-world multicenter registry including consecutive patients admitted for ACS. For the purpose of this analysis, patients were stratified according to diabetes status and insulin therapy. We compared 1-year rates of major adverse cardiovascular events, a composite of cardiovascular death, myocardial infarction and stroke, and of any bleeding, according to diabetes status (no diabetes, diabetes not on insulin therapy, diabetes on insulin therapy). In addition, we evaluated the net clinical benefit of dual antiplatelet therapy with the newer P2Y12 inhibitors (ticagrelor or prasugrel) vs dual antiplatelet therapy with clopidogrel according to diabetes status.

Results

In an overall population of 907 patients, 198 had diabetes, 10.6% of whom were on insulin. From non-diabetic patients to diabetic patients not on insulin and diabetic patients on insulin there was a stepwise decrease of MACE-free survival (log-rank p 0.039) with incidence of events at 1 year being 3.8%, 6.8% (adjusted p vs no diabetes 0.49) and 12.5% (adjusted p vs no diabetes 0.047), respectively (Figure, panel A). The rates of any bleeding were higher in patients on insulin (20.8% vs 8.8% in those without diabetes and 5.8% in diabetic patients not receiving insulin; log-rank p 0.028; Figure, panel B). Multivariable analysis demonstrated an almost 5-fold increase of any bleeding in diabetic patients with vs without insulin (OR 4.98, 95% CI 1.46–16.92; p=0.010). In the overall population, the incidence of the net composite endpoint including MACE or major bleeding with the use of ticagrelor/prasugrel on top of aspirin was significantly lower compared to use of clopidogrel (4.7% vs 8.4%; OR 0.54, 95% CI 0.30–0.94, p=0.031). This net clinical benefit in patients receiving a newer P2Y12 inhibitor was regardless of the diabetes status (p for interaction 0.48).

Conclusions

In this cohort of ACS patients, the presence of diabetes stratified by insulin therapy was associated with a graded increase in the 1-year rates of MACE. Conversely, insulin therapy significantly contributed to the overall increase of bleeding risk in diabetes.

Funding Acknowledgement

Type of funding source: None

Clinical phenotypes of atrial fibrillation and risk of mortality: a cluster analysis

Background

Patients with atrial fibrillation (AF) experience a high mortality rate despite optimal antithrombotic treatment. Characteristics of AF patients at higher mortality risk have been barely described so far and no risk score has been specifically developed at this aim. Furthermore, a clinical approach based on risk scores present some limits such as to not consider some important risk factors for mortality, and many available scores have poor predictive value. Cluster analysis may play a role in overcoming limitations of risk scores, especially in the case of overlapping risk factors.

Purpose

To identify of clinical phenotypes by using an unbiased statistical approach, such as the cluster analysis.

Methods

Cluster analysis was used to identify clinical phenotypes of AF patients associated with all-cause mortality in 5,171 AF patients from the START registry. Clinical variables used for the analysis were age, sex, diabetes, previous cerebrovascular events, previous cardiovascular events, heart failure, peripheral artery disease, use of non-vitamin K oral anticoagulants, cancer, pulmonary disease, smoking habit, previous major bleeding. The risk of all-cause mortality in each cluster was analyzed.

Results

We identified 4 clusters (Figure 1). Cluster 1 was composed by youngest patients, with obesity and paroxysmal AF; Cluster 2 by patients with low cardiovascular risk factors and high proportion of cancer; Cluster 3 by men with diabetes and coronary and peripheral artery disease, a high proportion of thrombocytopenia, and a high use of aspirin, proton pump inhibitors, and statins; Cluster 4 included the oldest patients, mainly women, with previous cerebrovascular disease, persistent/ permanent AF, heart failure, kidney disease and anemia. In this cluster there was the highest use of digoxin and NOACs.

During 9856,84 patient/years of observation, 386 deaths (3.92%/year) occurred. Mortality rates significantly increased across clusters: 0.42%/year (cluster 1, reference group), 2.12%/year (cluster 2, adjusted hazard ratio [aHR] 3.306, 95% confidence interval [CI] 1.204–9.077, p=0.020), 4.41%/year (cluster 3, aHR 6.702, 95% CI 2.433–18.461, p&lt;0.001) and 8.71%/year (cluster 4, aHR 8.927, 95% CI 3.238–24.605, p&lt;0.001).

Conclusions

We identified different clinical phenotypes of AF patients by cluster analysis which were specifically associated with mortality. This approach may help identify patients at higher risk of mortality.

Figure 1

Funding Acknowledgement

Type of funding source: None

Clinical outcome with NOACs vs VKAs in patients with atrial fibrillation and severe chronic kidney disease: results of a retrospective, multicenter, real-world study

Background

Patients with atrial fibrillation (AF) and severe chronic kidney disease (CKD) are at higher risk of both bleeding and thromboembolic events. Non-vitamin K antagonist oral anticoagulants (NOACs) are licensed to be used in these patients, although they were excluded from phase III controlled randomized trials comparing NOACs vs warfarin in AF. Thus, current evidence on NOACs use in such setting of patients is not definitive.

Purpose

Aim of our multicenter study was to perform a real-world comparison of clinical outcome with NOACs vs vitamin K antagonist anticoagulants (VKAs) also in AF patients having an estimated glomerular filtration rate (eGFR) 15–29 mL/min.

Methods

We retrospectively included a total of 266 patients receiving NOACs (N=159) or VKAs (N=107). Primary outcome measure was the cumulative incidence of the net composite endpoint including ischemic stroke, systemic thromboembolism or any bleeding. Mean follow-up was 2.6 years.

Results

CHA2DS2-VASc and HAS-BLED scores at baseline were similar in the two groups (3.4±1.3 with NOACs vs 3.4±0.9 with VKAs and 3.1±1.0 vs 3.0±0.7, respectively); eGFR and hemoglobin values were also comparable (31.8±12.3 vs 32±11.9 mL/min and 10.2±2.1 vs 11.0±2.3 g/dL, respectively). NOACs were not inferior to VKAs for the primary net composite endpoint: incidence 20.7% vs 29.9%, p&lt;0.01 for non-inferiority, p=0.11 for superiority. In proportional Cox regression model, hazard ratio for the primary outcome measure with NOACs use was 0.74 (95% CI 0.45–1.21, p=0.22). In the NOAC group there was a trend towards reduction in minor bleeding complications (p=0.08).

Conclusions

Our real-world data indicate that in patients with AF and severe renal failure NOACs are not inferior to VKAs for both safety and efficacy. The use of NOACs was associated with a numerically lower incidence of minor bleeding.

Funding Acknowledgement

Type of funding source: None

Effect of body mass index on ischemic and bleeding events in patients presenting with acute coronary syndromes: insights from the START-ANTIPLATELET registry

Background

The protective effect of obesity on mortality in acute coronary syndromes (ACS) patients remains debated. We aimed at evaluating the impact of obesity on ischemic and bleeding events as possible explanations to the obesity paradox in ACS patients.

Methods

For the purpose of this sub-study, patients enrolled in the START-ANTIPLATELET registry were stratified according to Body Mass Index (BMI) into three groups: normal, BMI &lt;25kg/m2; overweight, BMI: 25–29.9kg/m2; obese, BMI ≥30kg/m2. The primary endpoint was net adverse clinical endpoints (NACE), defined as a composite of all-cause death, myocardial infarction (MI), stroke, and major bleeding.

Results

Patients were classified as follows: 410 (33.9%) normal, 538 (44.5%) overweight, 261 (21.6%) obese. Compared to the normal weight group, obese and overweight patients had a higher prevalence of cardiovascular risk factors, but were younger, with a better left ventricular ejection fraction (LVEF) and lower PRECISE-DAPT score. At one-year follow-up NACE was more frequently observed in normal than in overweight and obese patients (15.1%,8.6%,and9.6%, respectively; p=0.004), driven by a significantly higher rate of all-cause death (6.3%,2.6%, and 3.8%, respectively; p=0.008), while no significant differences were noted in terms of MI, stroke, and major bleeding. When correcting for confounding variables, BMI loses its power in independently predicting outcomes, failing to confirm the obesity paradox in a real-world ACS population.

Conclusions

Our study conflicts the obesity paradox in real-world ACS population, and suggest that the reduced mortality rate may be explained by a lower bleeding risk in obese patients allowing a more aggressive medical treatment, and by a better LVEF translating into a higher survival rate.

Funding Acknowledgement

Type of funding source: None

Ticagrelor versus Clopidogrel in high bleeding risk patients presenting with Acute Coronary Syndromes: insights from the multicenter START-ANTIPLATELET registry

Background

Optimal dual antiplatelet therapy in high bleeding risk (HBR) patients with acute coronary syndromes (ACS) remains debated. Although current guidelines recommend the use of potent P2Y12 inhibitors in these patients (according to the labeled indications), clopidogrel is frequently used in clinical practice based on a perceived advantage in terms of safety in the HBR population.

Purpose

We sought to investigate the use of clopidogrel versus ticagrelor in consecutive HBR ACS patients and their impact on ischemic and bleeding events at 1 year.

Methods

ACS patients enrolled in the START-ANTIPLATELET registry with at least 1 HBR criterion were included in the present analysis and stratified according to DAPT type (clopidogrel versus ticagrelor). The primary endpoint was net adverse clinical endpoint (NACE), defined as a composite of all-cause death, myocardial infarction, stroke, and major bleeding. The secondary endpoints were major adverse cardiac and cerebral events (MACE), defined as a composite of all-cause death, myocardial infarction and stroke, each individual component of NACE and MACE, and target vessel revascularization.

Results

Among a total of 1,209 patients with 1-year follow-up in the registry, 383 patients were considered at HBR, of whom 174 (45.4%) were on clopidogrel and 209 (54.6%) on ticagrelor. Clopidogrel was more likely to be administered in patients at increased ischemic and bleeding risk, while ticagrelor in those undergoing percutaneous coronary intervention. Mean DAPT duration was longer in the ticagrelor group than in the clopidogrel group (10.40±4.29 versus 9.35±5.4; p-value=0.03). At 1-year follow-up, the risk of NACE and MACE events was significantly higher in the clopidogrel than in the ticagrelor group (NACE: HR 1.82; 95% CI 1.07–3.09; p-value=0.02; MACE: HR 1.83; 95% CI 1.04–3.24; p-value=0.03) (Figure). After multivariate adjustment for clinical and procedural characteristics, no difference in NACEs nor MACEs was observed between patients on clopidogrel versus ticagrelor (NACE: adjusted HR 1.27; 95% CI 0.71–2.27; p-value=0.42; MACE: adjusted HR 1.19; 95% CI 0.63–2.24; p-value=0.59) (Figure). Age, number of HBR criteria, and mean DAPT duration were independent predictors of NACEs.

Conclusions

In a real-world ACS registry, approximately 50% of patients are at HBR and frequently treated with clopidogrel. In HBR ACS patients, no difference was observed in ischemic and bleeding events between clopidogrel and ticagrelor after adjustment for potential confounders.

Kaplan-Meier curves at 1-year follow-up.

Funding Acknowledgement

Type of funding source: None

Risk of cardiovascular events in patients with atrial fibrillation and cancer. Data from the ATHERO-AF cohort

Background

Patients with non valvular atrial fibrillation (AF) and cancer represent a high-risk subgroup of patients in whom the management of oral anticoagulation may be challenging. The relationship between cancer type and the risk of cardiovascular events (CVEs) in patients with AF is unclear.

Purpose

To investigate the incidence of CVEs in patients with AF and cancer according to cancer type.

Methods

Prospective cohort study including 2,092 consecutive AF patients on vitamin K antagonists. Principal endpoint was the occurrence of CVEs including fatal/non-fatal myocardial infarction and ischemic stroke and cardiovascular death. We also performed a subgroup analysis of cardiac and thromboembolic events separately. Patients with cancer were divided in subgroups based on cancer site as follows: group 1 gastrointestinal tract; group 2 respiratory tract; group 3 genitourinary tract; group 4 other sites.

Results

Mean age was 73.7±9.1 years and 42.1% were woman; 367 (17.5%) had cancer, of these 21% gastro-intestinal, 10% respiratory, 28% genito-urinary and 41% had other localization. Patients with cancer were older than those without but with similar clinical characteristics.

During a mean follow up of 35.9±28.0 months (6264.5 patient-years), 203 CVEs occurred (3.24%/year, 95% CI 2.81–3.72) of whom 86 were cardiac ischemia (1.37%/year, 95% CI 1.10–1.69), 70 thromboembolic events (1.12%/year, 95% CI 0.87–1.41) and 47 cardiovascular deaths (0.75%/year, 95% CI 0.55–0.99). The incidence of CVEs for AF patients with and without cancer was respectively (n=45, 3.78%, 95% CI 2.76–5.06) and (n=158, 3.11%/year, 95% CI 2.65–3.64). In particular, compared to patients without cancer, a higher incidence rate of CVEs was found in patients with gastrointestinal tract cancer (5.61%/year, 95% CI 2.90–9.79, p=0.046), and in patients with respiratory tract cancer (6.15%/year, 95% CI 2.66–12.1, p=0.055), while no difference was found in patients with genito-urinary tract cancer (2.24%/year, 95% CI 0.97–4.41, p=0.362) and other site cancer (3.11%/year, 95% CI 2.65–3.64, p=0.512).

Cox regression multivariate analysis showed that factors associated with cardiac events were COPD, dyslipidemia, TTR &lt;70%, PPI drugs and gastrointestinal cancer (figure). Conversely, CHA2DS2VASc score and respiratory cancer were predictors of thromboembolic events.

Conclusions

Our findings suggest an association between cancer type and specific ischemic complications in AF patients. In particular, we found a higher risk of cardiac complications in patients with gastrointestinal cancer and of thromboembolic events in patients with respiratory cancer. These associations need to be confirmed in larger studies.

Funding Acknowledgement

Type of funding source: None

Fine scale spatial investigation of multiple insecticide resistance and underlying target-site and metabolic mechanisms in Anopheles gambiae in central Côte d'Ivoire

Routine monitoring of occurrence, levels and mechanisms of insecticide resistance informs effective management strategies, and should be used to assess the effect of new tools on resistance. As part of a cluster randomised controlled trial evaluating a novel insecticide-based intervention in central Côte d’Ivoire, we assessed resistance and its underlying mechanisms in Anopheles gambiae populations from a subset of trial villages. Resistance to multiple insecticides in An. gambiae s.s. and An. coluzzii was detected across villages, with dose–response assays demonstrating extremely high resistance intensity to the pyrethroid deltamethrin (> 1,500-fold), and mortality following exposure to pyrethroid-treated bednets was low (< 30% mortality in cone bioassays). The 1014F kdr mutation was almost fixed (≥ 90%) in all villages but the 1575Y kdr-amplifying mutation was relatively rare (< 15%). The carbamate and organophosphate resistance-associated Ace-1 G119S mutation was also detected at moderate frequencies (22–43%). Transcriptome analysis identified overexpression of P450 genes known to confer pyrethroid resistance (Cyp9K1, Cyp6P3, and Cyp6M2), and also a carboxylesterase (COEAE1F) as major candidates. Cyp6P3 expression was high but variable (up to 33-fold) and correlated positively with deltamethrin resistance intensity across villages (r² = 0.78, P = 0.02). Tools and strategies to mitigate the extreme and multiple resistance provided by these mechanisms are required in this area to avoid future control failures.

Cross-resistance profiles of malaria mosquito P450s associated with pyrethroid resistance against WHO insecticides

Extensive use of pyrethroids for malaria control in Africa has led to widespread pyrethroid resistance in the two major African vectors of malaria An. gambiae and An. funestus. This is often associated with constitutively elevated levels of cytochrome P450s involved with pyrethroid metabolism and detoxification. P450s have the capacity to metabolise diverse substrates, which raises concerns about their potential to cause cross-resistance. A bank of seven recombinant P450s from An. gambiae (CYPs 6M2, 6P2, 6P3, 6P4, 6P5, 9J5) and An. funestus (CYP6P9a) commonly associated with pyrethroid resistance were screened against twelve insecticides representing the five major classes of insecticides recommended by WHO for malaria control; permethrin, etofenprox and bifenthrin (type I pyrethroids), deltamethrin, lambda cyhalothrin and cypermethrin (type II pyrethroids), DDT (organochlorine), bendiocarb (carbamate), malathion, pirimiphos methyl and fenitrothion (organophosphates) and pyriproxyfen (juvenile hormone analogue). DDT was not metabolised by the P450 panel, while bendiocarb was only metabolised by CYP6P3. Pyrethroids and pyriproxyfen were largely susceptible to metabolism by the P450 panel, as were organophosphates, which are activated by P450s. Primiphos-methyl is increasingly used for malaria control. Examination of the pirimiphos-methyl metabolites generated by CYP6P3 revealed both the active pirimiphos-methyl-oxon form and the inactive oxidative cleavage product 2-diethylamino-6-hydroxy-4-methylpyrimidine. The inhibition profile of CYPs 6M2, 6P2, 6P3, 6P9a and 9J5 was also examined using diethoxyfluorescein (DEF) as the probe substrate. Bendiocarb was the weakest inhibitor with IC₅₀ > 100 μM across the P450 panel, while CYP6M2 showed strongest inhibition by malathion (IC₅₀ 0.7 μM). The results suggest that P450s present at elevated levels in two major Anopheline vectors of malaria in Africa have the capacity to metabolise a diverse range of pyrethroid and organophosphate insecticides as well as pyriproxyfen that could impact vector control.

P3472Modifications of renal function in atrial fibrillation patients treated with different oral anticoagulants: a multicentre cohort study

Background

A decline of estimated glomerular filtration rate (eGFR) has been described in atrial fibrillation (AF) patients on Vitamin K antagonists (VKAs). Few real-world data on the modifications of eGFR in AF patients treated with non-vitamin K antagonist oral anticoagulants (NOACs) do exist.

Purpose

To evaluate changes of renal function in AF patients treated with VKAs or NOACs.

Methods

Multicentre prospective cohort study including 1,667 patients with non-valvular AF from 5 clinical centres of Internal Medicine and Cardiology in Italy.

Renal endpoints were: 1) median annual decline of eGFR; 2) transition to eGFR <50 ml/min/1.73 m2; 3) eGFR class worsening according to KDIGO 2012 classification. The eGFR was assessed by the CKD-EPI formula at baseline and during follow-up.

Results

Median age was 73.7±9.1 years and 43.3% were women. 743 patients were on VKAs and 924 on NOACs (Dabigatran, Rivaroxaban e Apixaban). Median annual eGFR decline was −2,11 (Interquartile Range [IQR] −5,68/−0,62] in patients on VKAs, −0,27 [IQR −9,00/4,54] with Dabigatran (p<0.001 vs. VKAs), −1,21 [IQR −9,98/4,02] with Rivaroxaban (p=0.004 vs. VKAs) and −1,32 [IQR −8,7/3,99] with Apixaban (p=0.003, vs. VKAs). Use of Dabigatran and Apixaban was associated to a lower transition to eGFR <50 mL/min/1.73 m2, compared to VKAs: adjusted Odds Ratio (aOR) 0.492, 95% Confidence Interval (CI) 0.298–0.813, p=0.006 for Dabigatran; aOR 0.449, 95% CI 0.276–0.728, p=0.001 for Apixaban). Regarding the eGFR class worsening, Dabigatran (aOR 0.70, 95% CI 0.503–0.975, p=0.035), Rivaroxaban (aOR 0.591, 95% CI 0.423–0.825, p=0.002), and Apixaban (aOR 0.591, 95% CI 0.429–0.815, p=0.001) were all associated to a lower rate of eGFR class worsening compared to VKAs.

Forest plot

Conclusions

In this prospective multicentre cohort study, NOACs use was associated with a lower decline of renal function compared to VKAs. Patients on Dabigatran showed the lowest annual rate of eGFR decline and those on Apixaban and Rivaroxaban a lower eGFR class worsening.

Acknowledgement/Funding

None

P5454PCSK9 as a predictor of cardiovascular events in atrial fibrillation: role of platelet activation

Background

High circulating levels of proprotein convertase subtilisin/kexin 9 (PCSK9) were shown to be predictive of cardiovascular events (CVEs) in patients with atrial fibrillation (AF). Because high PCSK9 plasma levels were significantly correlated with 11-dehydro-thromboxane B2 (11-dh-TxB2), a marker of platelet activation, it is conceivable to hypothesize a direct effect of PCSK9 on platelet activation but the mechanism is still unclear.

Purpose

We evaluated the association between PCSK9 and platelet activation in FA patients and investigate the possible molecular mechanism involved.

Methods

According to our previous prospective study, we conducted a post-hoc analysis including 50 patients with baseline PCSK9 below and 50 above the median value of 1200pg/ml. The two groups were balanced for age and sex. In vivo platelet activation was assessed by aggregation (PA), recruitment, plasma thromboxane B2 (TxB2) formation and sPselectin levels. As markers of oxidative stress we used sNox2-dp, H2O2 production, urinary isoprostanes and oxLDL. To asses the role of PCSK9 in platelet activation, we performed an in vitro study with platelets from healthy subjects (n=5) added with PCSK9 concentrations achievable in human circulation (1000pg/ml and 2000pg/ml) measuring PA, TxB2, isoprostanes production, Nox2 activation, H2O2 production, oxLDL, p38, p47 and PLA2 phosphorylation.

Results

We observed an increased of platelet activation and oxidative stress in patients with PCSK9 levels above median (1200pg/ml) compared to those below (p<0.05). A significant correlation between plasma levels of PCSK9 and markers of platelet activation and markers of oxidative stress were found. In vitro study demonstrated that PCSK9, at the concentration similar to that of patients with CVEs, was able to increase platelet activation act by binding oxLDL receptor. PCSK9 dependent platelet activation is mediated by p47 phosphorylation, a key step in Nox2 activation and is mediated by the PLA2 phosporylation.

Conclusions

PCSK9, at concentration achievable in patients with CVEs, increased platelet aggregation via oxLDL receptor with a pathway involving Nox2 activation.

The Anopheles gambiae ATP-binding cassette transporter family: phylogenetic analysis and tissue localization provide clues on function and role in insecticide resistance

The role of ATP-binding cassette (ABC) transporters in conferring insecticide resistance has received much attention recently. Here we identify ABC transporters differentially expressed in insecticide-resistant populations of the malaria vector, Anopheles gambiae. Although we found little evidence that the orthologues of the multidrug resistance proteins described in other species are associated with resistance in An. gambiae we did identify a subset of ABC proteins consistently differentially expressed in pyrethroid-resistant populations from across Africa. We present information on the phylogenetic relationship, primary sites of expression and potential role of ABC transporters in mediating the mosquito's response to insecticides. Furthermore we demonstrate that a paralogous group of eight ABCG transporters, clustered on chromosome 3R, are highly enriched in the legs of An. gambiae mosquitoes, consistent with a proposed role for this ABC subfamily in transport of lipids to the outer surface of the cuticle. Finally, antibodies raised against one of the most highly expressed ABC transporters in adult females, ABCG7 (AGAP009850), localized this transporter to the pericardial cells. These data will help prioritize members of this gene family for further localization and functional validation studies to identify the in vivo function of these transporters in the mosquito and determine whether elevated expression of members of this family contribute to insecticide resistance.

Aging and Adherence to the Mediterranean Diet: Relationship with Cardiometabolic Disorders and Polypharmacy

OBJECTIVES

To investigate the association between adherence to the Mediterranean Diet (Med-Diet), cardiometabolic disorders and polypharmacy.

DESIGN

Cross-sectional study.

SETTING

Geriatrics outpatient clinic, Policlinico Umberto I, Sapienza University of Rome.

PARTICIPANTS

508 patients (219 male, 289 female) aged 50 to 89 who were evaluated for cardiovascular and metabolic disorders.

METHODS AND MEASUREMENTS

Patients underwent a comprehensive medical assessment including medical history and the use of medications. Adherence to Med-Diet was assessed using the validated Med-Diet 14-item questionnaire; for the analysis, patients were divided in high (≥8) and medium-low (<8) adherence. Polypharmacy was defined as taking ≥5 medications.

RESULTS

476 patients completed the study. Mean age was 70.4 years; 58% female. Median Med-Diet score was 8 (interquartile range, 6-9). Patients with medium-low adherence had higher body mass index (p=0.029) and higher prevalence of arterial hypertension (p<0.001), previous coronary (p=0.002) and cerebrovascular events (p=0.011), diabetes, (p<0.001) and dyslipidemia (p=0.001) compared to those at high adherence. Med-Diet score decreased with the number of cardiometabolic disorders (p<0.001). The prevalence of polypharmacy was 39%. Consumption of olive oil (p=0.005), vegetables, (p<0.001), wine (p=0.017), legumes (p=0.028), fish (p=0.046) and nuts (p=0.045) were all inversely associated with the overall number of medications. In a multivariable regression model, medium-low adherence to Med-Diet was independently associated to polypharmacy (O.R.:1.859; 95% CI 1.142 to 3.025; p=0.013), after adjusting for possible confounding factors.

CONCLUSION

Med-Diet was inversely associated with cardiometabolic disorders and with polypharmacy, suggesting that improved Med-Diet adherence might potentially delay the onset of age-related health deterioration and reduce the need of multiple medications.

Platelet Activation and Cytokine Production during Hypothermic Cardiopulmonary Bypass – A Possible Correlation?

Cardiopulmonary bypass (CPB) is associated with impaired platelet function and a systemic inflammatory response. The present study was designed to evaluate whether any correlation between platelet activation and inflammatory response during CPB exists. The results obtained from 8 patients undergoing hypothermic CPB for cardiac surgery showed the occurrence of a moderate degree of platelet activation during CPB, demonstrated by an increase of platelet CD62P expression in correlation with an increase of β-thromboglobulin levels, with a concomitant decrease of in vitro platelet response. Plasma IL-1β levels significantly increased during CPB, with a peak between 1 and 4 h after CPB. Similarly, IL-6 levels were elevated 30 min from CPB starting, peaked at 4 h, and remained elevated after 24 h. A direct correlation was found between plasma IL-1β and IL-6 levels. A significant correlation between plasma IL-1β and β-thromboglobulin levels was also found. In turn, plasma β-thromboglobulin levels correlated with CD62P expression on activated platelets. An inverse correlation was found between in vitro platelet aggregation and plasma IL-1β or IL-6 levels. From the present results it may be speculated that platelet activation during CPB may contribute, through the release of IL-1β, to activation of endothelial cells and subsequent release of other cytokines with chemotactic and pro-inflammatory properties, thus playing an important role in the inflammatory response associated with CPB.

Instant loading with intraoral welding technique and PRAMA implants: a new prosthetic approach

When splinting multiple implants passive fit of the framework should be achieved to avoid excessive force distribution on the implants. Recently, a protocol was suggested for immediate loading of multiple implants by welding a titanium bar to implant abutments directly in the oral cavity so as to create a customized, precise and passive metal-reinforced provisional restoration. The intraoral welding technique subsequently proves to be a successful option in the full-arch immediate restorations of the mandible and maxilla. The aim of this article is to present a case report in which a new prosthetic approach, using trans-mucosal implants, is described. Dental implants are instantly loaded with a provisional prosthesis supported by an intraoral welded titanium framework to obtain a precise passive fit of the immediate loaded prosthesis.

The transcription factor Maf-S regulates metabolic resistance to insecticides in the malaria vector Anopheles gambiae

Background

Malaria control in Africa is dependent upon the use insecticides but intensive use of a limited number of chemicals has led to resistance in mosquito populations. Increased production of enzymes that detoxify insecticides is one of the most potent resistance mechanisms. Several metabolic enzymes have been implicated in insecticide resistance but the processes controlling their expression have remained largely elusive.

Results

Here, we show that the transcription factor Maf-S regulates expression of multiple detoxification genes, including the key insecticide metabolisers CYP6M2 and GSTD1 in the African malaria vector Anopheles gambiae. Attenuation of this transcription factor through RNAi induced knockdown reduced transcript levels of these effectors and significantly increased mortality after exposure to the pyrethroid insecticides and DDT (permethrin: 9.2% to 19.2% (p = 0.015), deltamethrin: 3.9% to 21.6% (p = 0.036) and DDT: 1% to 11.7% (p = <0.01), whilst dramatically decreasing mortality induced by the organophosphate malathion (79.6% to 8.0% (p = <0.01)). Additional genes regulated by Maf-S were also identified providing new insight into the role of this transcription factor in insects.

Conclusion

Maf-S is a key regulator of detoxification genes in Anopheles mosquitoes. Disrupting this transcription factor has opposing effects on the mosquito’s response to different insecticide classes providing a mechanistic explanation to the negative cross resistance that has been reported between pyrethroids and organophosphates.

Electronic supplementary material

The online version of this article (10.1186/s12864-017-4086-7) contains supplementary material, which is available to authorized users.

First detection of N1575Y mutation in pyrethroid resistant Anopheles gambiae in Southern Côte d'Ivoire

Background. The intensification of insecticide use for both public health and agriculture in Africa has contributed to growing insecticide resistance. Today, resistance to World Health Organization (WHO)-approved insecticide classes is widespread. In an agricultural area of Southern Côte d’Ivoire, the main malaria vector Anopheles coluzzii shows multiple resistance across insecticides mediated by both target site mutation and metabolic mechanisms. To plan new vector control strategies and avert future resistance liabilities caused by cross-resistance mechanisms extant within populations, it is crucial to monitor the development and spread of both resistance and mechanisms.

Methods.  Larvae of Anopheles gambiae were collected from natural breeding sites in Tiassalé and Elibou, between April and November 2016 and raised to adults . Adult female non-blood fed mosquitoes, three to five days old, were exposed to deltamethrin in WHO bioassays. Extracted DNA samples from exposed mosquitoes were used for species characterisation and genotyping.

Results. Most adult An. gambiae tested were resistant to deltamethrin, with mortality rates of only 25% in Tiassalé and 4.4% in Elibou. Molecular analysis of DNA from samples tested showed the presence of both An. coluzzii and An. gambiae s.s in Elibou and only An. coluzzii for Tiassalé. As previously, the L1014F kdr mutation was present at high frequency (79%) in Tiassalé and the L1014S mutation was absent. The N1575Y mutation, which amplifies resistance conferred by L1014F was detected in a single unique individual from a Tiassalé An. coluzzii female whereas in Elibou 1575Y was present in 10 An. gambiae s.s, but not in An. coluzzii.

Conclusion. This is the first report of the N1575Y mutation in Côte d’Ivoire, and as in other populations, it is found in both dominant West African malaria vector species. Continued monitoring of N1575Y is underway, as are studies to elucidate its contribution to the resistance of local vector populations.

Short-term in vivo modifications of platelet NADPH oxidase 2 (NOX2) and prostaglandin F2α in HIV-1 patients on abacavir-based therapies

OBJECTIVES

The aim of the study was to investigate the in vivo effect of abacavir (ABC) on platelet oxidative stress.

METHODS

We performed a randomized pilot study including 39 HIV-1-infected patients, 17 on zidovudine/lamivudine (ZDV/3TC) and 22 on tenofovir/emtricitabine (TDF/FTC). Ten patients on ZDV/3TC and eight patients on TDF/FTC were randomly allocated to switching the nucleoside backbone to ABC/3TC. At baseline and after 6 months, platelet oxidative stress was assessed by platelet NADPH oxidase 2 (NOX2)-derived peptide (sNOX2-dp), a marker of NOX2 activation, and platelet prostaglandin F_2α (8-iso-PGF_2α ). Platelet activation was measured by soluble CD40L (sCD40L).

RESULTS

At baseline, no differences between ZDV/3TC or TDF/FTC recipients were found. After 6 months, patients switching from ZDV/3TC showed a decrease of sNOX2-dp (from 20.9±5.7 to 12.5±3.8 pg/ml, p=0.002) and 8-iso-PGF_2α (from 154.3±41.9 to 122.9±28.0 pmol/l, p=0.025). No effects on platelet oxidative stress biomarkers were observed in subjects from TDF/FTC, who showed a significant increase in blood glucose (p=0.043) and total cholesterol (p=0.027). ABC showed no effect on sCD40L levels in both groups.

CONCLUSIONS

ABC reduced platelet sNOX2-dp and 8-iso-PGF_2α in HIV-1 subjects switching from ZDV/3TC but not in those from TDF/FTC after 6 months. No changes in platelet activation were found in both groups.

Assessment of risk factors for candidemia in non-neutropenic patients hospitalized in Internal Medicine wards: A multicenter study

BACKGROUND

An increasing prevalence of candidemia has been reported in Internal Medicine wards (IMWs). The aim of our study was to identify risk factors for candidemia among non-neutropenic patients hospitalized in IMWs.

METHODS

A multicenter case-control study was performed in three hospitals in Italy. Patients developing candidemia (cases) were compared to patients without candidemia (controls) matched by age, time of admission and duration of hospitalization. A logistic regression analysis identified risk factors for candidemia, and a new risk score was developed. Validation was performed on an external cohort of patients.

RESULTS

Overall, 951 patients (317 cases of candidemia and 634 controls) were included in the derivation cohort, while 270 patients (90 patients with candidemia and 180 controls) constituted the validation cohort. Severe sepsis or septic shock, recent Clostridium difficile infection, diabetes mellitus, total parenteral nutrition, chronic obstructive pulmonary disease, concomitant intravenous glycopeptide therapy, presence of peripherally inserted central catheter, previous antibiotic therapy and immunosuppressive therapy were factors independently associated with candidemia. The new risk score showed good area under the curve (AUC) values in both derivation (AUC 0.973 95% CI 0.809-0.997, p<0.001) and validation cohort (0.867 95% CI 0.710-0.931, p<0.001). A threshold of 3 leads to a sensitivity of 87% and a specificity of 83%.

CONCLUSION

Non-neutropenic patients admitted in IMWs have peculiar risk factors for candidemia. A new risk score with a good performance could facilitate the identification of candidates to early antifungal therapy.

EVOLUTIONARY EFFECTS OF SELECTION ON AGE AT REPRODUCTION IN LARVAL AND ADULT: DROSOPHILA MELANOGASTER

Two sets of three replicate lines of Drosophila melanogaster were artificially selected by reproduction at either a 'young' or an 'old' age. The pure lines, the hybrids between the lines within a selection regimen and the base stock from which the lines were derived were compared for longevity, early and late fertility, development time, larval viability and adult thorax length. Comparison of hybrid with pure lines showed some evidence for inbreeding depression in the lines from both selection regimes. Comparison of hybrid lines with the base stock did not provide evidence for any trade-off in either males or females between early fertility on the one hand and late life fertility and longevity on the other. Nor was there any clear evidence of a trade-off between pre-adult and adult fitness components. There was evidence of inadvertent selection for rapid development in both selection regimens, especially in the females of the 'young' lines, and this complicated the interpretation of the responses and correlated responses to selection. An improvement in adult performance in the 'old' line males relative to the base stock appeared to be attributable to reversal of mutation accumulation. Comparison of the hybrid 'young' and 'old' lines with the base stock did not support the idea that the superior longevity and late life fertility of the 'old' lines relative to the 'young' lines could be accounted for by the effects of mutation accumulation in the 'young' lines. The results point to the need to compare selected lines with their base stock when deducing responses and correlated responses to selection and to avoid unintentional selection. In this type of experiment, larval density should be standardized during selection, and adults should not be under pressure for rapid maturation.

Pyriproxyfen is metabolized by P450s associated with pyrethroid resistance in An. gambiae

Pyrethroid resistance is widespread in the malaria vector Anopheles gambiae leading to concerns about the future efficacy of bednets with pyrethroids as the sole active ingredient. The incorporation of pyriproxyfen (PPF), a juvenile hormone analogue, into pyrethroid treated bednets is being trialed in Africa. Pyrethroid resistance is commonly associated with elevated levels of P450 expression including CYPs 6M2, 6P2, 6P3, 6P4, 6P5, 6Z2 and 9J5. Having expressed these P450s in E. coli we find all are capable of metabolizing PPF. Inhibition of these P450s by permethrin, deltamethrin and PPF was also examined. Deltamethrin and permethrin were moderate inhibitors (IC₅₀ 1-10 μM) of diethoxyfluorescein (DEF) activity for all P450s apart from CYP6Z2 (IC₅₀ > 10 μM), while PPF displayed weaker inhibition of all P450s (IC₅₀ > 10 μM) except CYP's 6Z2 and 6P2 (IC₅₀ 1-10 μM). We found evidence of low levels of cross resistance between PPF and other insecticide classes by comparing the efficacy of PPF in inhibiting metamorphosis and inducing female sterility in an insecticide susceptible strain of An. gambiae and a multiple resistant strain from Cote d'Ivoire.

Enhanced Soluble Serum CD40L and Serum P-Selectin Levels in Primary Aldosteronism

Primary aldosteronism (PA) is one of the most frequent forms of secondary hypertension, associated with atherosclerosis and higher risk of cardiovascular events. Platelets play a key role in the atherosclerotic process. The aim of the study was to evaluate the platelet activation by measuring serum levels of soluble CD40L (sCD40L) and P-selectin (sP-selectin) in consecutive PA patients [subgroup: aldosterone-secreting adrenal adenoma (APA) and bilateral adrenal hyperplasia (IHA)], matched with essential hypertensive (EH) patients. The subgroup of APA patients was revaluated 6-months after unilateral adrenalectomy. In all PA group, we measured higher serum levels of both sP-selectin (14.29±9.33 pg/ml) and sCD40L (9.53±4.2 ng/ml) compared to EH patients (9.39±5.3 pg/ml and 3.54±0.94 ng/ml, respectively; p<0.001). After removal of APA, PA patients showed significant reduction of blood pressure (BP) values, plasma aldosterone (PAC) levels and ARR-ratio, associated with a significant reduction of sP-selectin (16.74±8.9 pg/ml vs. 8.1±3.8 pg/ml; p<0.01) and sCD40L (8.6±1 ng/ml vs. 5.24±0.94 ng/ml; p<0.001). In PA patients, we found a significant correlation between sP-selectin and sCD40L with PAC (r=0.52, p<0.01; r=0.50, p<0.01, respectively); this correlation was stronger in APA patients (r=0.54; p<0.01 r=0.63; p<0.01, respectively). Our results showed that PA is related to platelet activation, expressed as higher plasma values of sCD40L and sP-selectin values. Surgical treatment and consequent normalization of aldosterone secretion was associated with significant reduction of sCD40L and sP-selectin values in APA patients.

Status of insecticide resistance in high-risk malaria provinces in Afghanistan

BACKGROUND

Insecticide resistance seriously threatens the efficacy of vector control interventions in malaria endemic countries. In Afghanistan, the status of insecticide resistance is largely unknown while distribution of long-lasting insecticidal nets has intensified in recent years. The main objective of this study was thus to measure the level of resistance to four classes of insecticides in provinces with medium to high risk of malaria transmission.

METHODS

Adult female mosquitoes were reared from larvae successively collected in the provinces of Nangarhar, Kunar, Badakhshan, Ghazni and Laghman from August to October 2014. WHO insecticide susceptibility tests were performed with DDT (4 %), malathion (5 %), bendiocarb (0.1 %), permethrin (0.75 %) and deltamethrin (0.05 %). In addition, the presence of kdr mutations was investigated in deltamethrin resistant and susceptible Anopheles stephensi mosquitoes collected in the eastern provinces of Nangarhar and Kunar.

RESULTS

Analyses of mortality rates revealed emerging resistance against all four classes of insecticides in the provinces located east and south of the Hindu Kush mountain range. Resistance is observed in both An. stephensi and Anopheles culicifacies, the two dominant malaria vectors in these provinces. Anopheles superpictus in the northern province of Badakhshan shows a different pattern of susceptibility with suspected resistance observed only for deltamethrin and bendiocarb. Genotype analysis of knock down resistance (kdr) mutations at the voltage-gated channel gene from An. stephensi mosquitoes shows the presence of the known resistant alleles L1014S and L1014F. However, a significant fraction of deltamethrin-resistant mosquitoes were homozygous for the 1014L wild type allele indicating that other mechanisms must be considered to account for the observed pyrethroid resistance.

CONCLUSIONS

This study confirms the importance of monitoring insecticide resistance for the development of an integrated vector management in Afghanistan. The validation of the kdr genotyping PCR assay applied to An. stephensi collected in Afghanistan paves the way for further studies into the mechanisms of insecticide resistance of malaria vectors in this region.

Dissecting the organ specificity of insecticide resistance candidate genes in Anopheles gambiae: known and novel candidate genes

Background

The elevated expression of enzymes with insecticide metabolism activity can lead to high levels of insecticide resistance in the malaria vector, Anopheles gambiae. In this study, adult female mosquitoes from an insecticide susceptible and resistant strain were dissected into four different body parts. RNA from each of these samples was used in microarray analysis to determine the enrichment patterns of the key detoxification gene families within the mosquito and to identify additional candidate insecticide resistance genes that may have been overlooked in previous experiments on whole organisms.

Results

A general enrichment in the transcription of genes from the four major detoxification gene families (carboxylesterases, glutathione transferases, UDP glucornyltransferases and cytochrome P450s) was observed in the midgut and malpighian tubules. Yet the subset of P450 genes that have previously been implicated in insecticide resistance in An gambiae, show a surprisingly varied profile of tissue enrichment, confirmed by qPCR and, for three candidates, by immunostaining. A stringent selection process was used to define a list of 105 genes that are significantly (p ≤0.001) over expressed in body parts from the resistant versus susceptible strain. Over half of these, including all the cytochrome P450s on this list, were identified in previous whole organism comparisons between the strains, but several new candidates were detected, notably from comparisons of the transcriptomes from dissected abdomen integuments.

Conclusions

The use of RNA extracted from the whole organism to identify candidate insecticide resistance genes has a risk of missing candidates if key genes responsible for the phenotype have restricted expression within the body and/or are over expression only in certain tissues. However, as transcription of genes implicated in metabolic resistance to insecticides is not enriched in any one single organ, comparison of the transcriptome of individual dissected body parts cannot be recommended as a preferred means to identify new candidate insecticide resistant genes. Instead the rich data set on in vivo sites of transcription should be consulted when designing follow up qPCR validation steps, or for screening known candidates in field populations.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2164-15-1018) contains supplementary material, which is available to authorized users.

Non-alcoholic fatty liver disease, metabolic syndrome and patatin-like phospholipase domain-containing protein3 gene variants

BACKGROUND & AIMS

Non-alcoholic fatty liver disease was traditionally interpreted as a condition which may progress to liver-related complications. However, the increased mortality is primarily a result of cardiovascular diseases. It has been suggested that fatty liver can be considered as the hepatic consequence of the metabolic syndrome. The aim was to describe the different clinical presentations of non-alcoholic fatty liver disease on the basis of the patatin-like phospholipase domain-containing protein3 (PNPLA3) rs738409 gene variant.

METHODS

Fatty liver was defined by ultrasonographic Hamaguchi's criteria in 211 consecutive subjects with non-alcoholic fatty liver disease. The rs738409 polymorphism was determined by TaqMan assays. Metabolic syndrome was defined according to ATPIII modified criteria.

RESULTS

Prevalence of PNPLA3-148II, PNPLA3-148IM, and PNPLA3-148MM genotypes was 45.0%, 40.7%, and 14.3% respectively. Prevalence of metabolic syndrome progressively increased with the severity of liver steatosis (from 52.5% to 65.2%, and 82.3% respectively, p<0.01). The PNPLA3-148MM group had significantly lower mean serum triglycerides (p<0.001), Framingham cardiovascular risk score (p<0.01) and lower prevalence of metabolic syndrome (p<0.05) and its components. Age and HOMA-IR were positive independent predictors of metabolic syndrome, while a negative independent association was found between metabolic syndrome and the homozygotes PNPLA3 I148M variant.

CONCLUSIONS

We suggest a lower prevalence of MetS and reduced cardiovascular risk in NAFLD patients with PNPLA3MM genotype.

Insecticide resistance in Anopheles arabiensis in Sudan: temporal trends and underlying mechanisms

Background

Malaria vector control in Sudan relies mainly on indoor residual spraying (IRS) and the use of long lasting insecticide treated bed nets (LLINs). Monitoring insecticide resistance in the main Sudanese malaria vector, Anopheles arabiensis, is essential for planning and implementing an effective vector control program in this country.

Methods

WHO susceptibility tests were used to monitor resistance to insecticides from all four WHO-approved classes of insecticide at four sentinel sites in Gezira state over a three year period. Insecticide resistance mechanisms were studied using PCR and microarray analyses.

Results

WHO susceptibility tests showed that Anopheles arabiensis from all sites were fully susceptible to bendiocarb and fenitrothion for the duration of the study (2008–2011). However, resistance to DDT and pyrethroids was detected at three sites, with strong seasonal variations evident at all sites. The 1014 F kdr allele was significantly associated with resistance to pyrethroids and DDT (P < 0.001) with extremely high effects sizes (OR > 7 in allelic tests). The 1014S allele was not detected in any of the populations tested. Microarray analysis of the permethrin-resistant population of An. arabiensis from Wad Medani identified a number of metabolic genes that were significantly over-transcribed in the field-collected resistant samples when compared to the susceptible Sudanese An. arabiensis Dongola strain. These included CYP6M2 and CYP6P3, two genes previously implicated in pyrethroid resistance in Anopheles gambiae s.s, and the epsilon-class glutathione-S-transferase, GSTe4.

Conclusions

These data suggest that both target-site mechanisms and metabolic mechanisms play an important role in conferring pyrethroid resistance in An. arabiensis from Sudan. Identification in An. arabiensis of candidate loci that have been implicated in the resistance phenotype in An. gambiae requires further investigation to confirm the role of these genes.

Pinpointing P450s associated with pyrethroid metabolism in the dengue vector, Aedes aegypti: developing new tools to combat insecticide resistance

BACKGROUND

Pyrethroids are increasingly used to block the transmission of diseases spread by Aedes aegypti such as dengue and yellow fever. However, insecticide resistance poses a serious threat, thus there is an urgent need to identify the genes and proteins associated with pyrethroid resistance in order to produce effective counter measures. In Ae. aegypti, overexpression of P450s such as the CYP9J32 gene have been linked with pyrethroid resistance. Our aim was to confirm the role of CYP9J32 and other P450s in insecticide metabolism in order to identify potential diagnostic resistance markers.

METHODOLOGY/PRINCIPAL FINDINGS

We have expressed CYP9J32 in Escherichia coli and show that the enzyme can metabolize the pyrethroids permethrin and deltamethrin. In addition, three other Ae. aegypti P450s (CYP9J24, CYP9J26, CYP9J28) were found capable of pyrethroid metabolism, albeit with lower activity. Both Ae. aegypti and Anopheles gambiae P450s (CYP's 6M2, 6Z2, 6P3) were screened against fluorogenic and luminescent substrates to identify potential diagnostic probes for P450 activity. Luciferin-PPXE was preferentially metabolised by the three major pyrethroid metabolisers (CYP9J32, CYP6M2 and CYP6P3), identifying a potential diagnostic substrate for these P450s.

CONCLUSIONS/SIGNIFICANCE

P450s have been identified with the potential to confer pyrethroid resistance in Ae.aegypti. It is recommended that over expression of these enzymes should be monitored as indicators of resistance where pyrethroids are used.

Dark chocolate inhibits platelet isoprostanes via NOX2 down-regulation in smokers

BACKGROUND

Dark chocolate is reported to decrease platelet activation but the underlying mechanism is still undefined. Dark chocolate is rich in polyphenols that could exert an antiplatelet action via inhibition of oxidative stress. The aim of the present study was to assess if dark chocolate inhibits platelet reactive oxidant species (ROS) formation and platelet activation.

METHODS

Twenty healthy subjects (HS) and 20 smokers were randomly allocated to receive 40 g of dark (cocoa > 85%) or milk chocolate (cocoa < 35%) in a cross-over, single-blind study. There was an interval of 7 days between the two phases of the study. At baseline and 2 h after chocolate ingestion, platelet recruitment (PR), platelet ROS, platelet isoprostane 8-ISO-prostaglandin F2α (8-iso-PGF2α), Thromboxane (TxA2) and platelet activation of NOX2, the catalytic sub-unit of NADPH oxidase, and serum epicatechin were measured.

RESULTS

Compared with HS, smokers showed enhanced PR, platelet formation of ROS and eicosanoids and NOX2 activation. After dark chocolate, platelet ROS (-48%, P < 0.001), 8-iso-PGF2α (-10%, P < 0.001) and NOX2 activation (-22%, P < 0.001) significantly decreased; dark chocolate did not affect platelet variables in HS. No effect of milk chocolate was detected in both groups. Serum epicatechin increased after dark chocolate in HS (from 0.454 ± 0.3 nm to 118.3 ± 53.7 nm) and smokers (from 0.5 ± 0.28 nm to 120.9 ± 54.2 nm). Platelet incubation with 0.1-10 μm catechin significantly reduced PR, platelet 8-iso-PGF2α and ROS formation and NOX2 activation only in platelets from smokers.

CONCLUSIONS

Dark chocolate inhibits platelet function by lowering oxidative stress only in smokers; this effect seems to be dependent on its polyphenolic content.

Effect of L-carnitine on oxidative stress and platelet activation after major surgery

BACKGROUND

The surgical/anesthesia trauma is associated with an increased production of reactive oxygen species (ROS). This enhanced oxidative stress leads to cell damage resulting in various complications such as sepsis, myocardial injury and increased mortality. The aim of this study was to investigate the role of antioxidant treatment with l-carnitine in oxidative stress and platelet activation in patients undergoing major abdominal surgery.

METHODS

Forty patients scheduled for abdominal surgery were randomly allocated to l-carnitine, administered with a rapid infusion (0.05 g/kg) diluted in 250 ml of saline solution, vs. placebo treatment just before the surgical intervention. At baseline and after treatment, oxidative stress was evaluated by detection of circulating levels of soluble NOX2-derived peptide (sNOX2-dp), a marker of NADPH oxidase activation, and by analyzing platelet ROS formation. Platelet activation was studied by dosing sCD40L.

RESULTS

We observed an increase of soluble sNOX2-dp, sCD40L and ROS production in the placebo group compared with the baseline after the surgical intervention. Conversely, in the l-carnitine-treated group, sNOX2-dp, sCD40L and ROS production did not significantly differ from the baseline. A linear correlation analysis showed that Δ of ROS correlated with Δ of sNOX2 (R(s) =0.817; P<0.001) and Δ of sCD40L (R(s) =0.780; P<0.001). Multiple linear regression analysis showed that the only independent predictive variable associated with Δ of ROS was Δ of serum NOX2 levels (SE=0.05; standardized coefficient β=1.075; P<0.001).

CONCLUSION

Our findings suggest that l-carnitine could be helpful in modulating oxidative stress and platelet activation during major abdominal surgery-dependent oxidative damage.

Cytochrome P450 6M2 from the malaria vector Anopheles gambiae metabolizes pyrethroids: Sequential metabolism of deltamethrin revealed

Resistance to pyrethroid insecticides in the malaria vector Anopheles gambiae is a major threat to malaria control programmes. Cytochome P450-mediated detoxification is an important resistance mechanism. CYP6M2 is over-expressed in wild populations of permethrin resistant A. gambiae but its role in detoxification is not clear. CYP6M2 was expressed in Escherichia coli and a structural model was produced to examine its role in pyrethroid metabolism. Both permethrin and deltamethrin were metabolized. Rates were enhanced by A. gambiae cytochrome b(5) with kinetic parameters of K(M)=11±1μM and k(cat)=6.1±0.4 per min for permethrin (1:1 cis-trans) and K(M)=2.0±0.3μM and k(cat)=1.2±0.1 per min for deltamethrin. Mass spectrometry and NMR analysis identified 4'-hydroxy deltamethrin and hydroxymethyl deltamethrin as major and minor deltamethrin metabolites respectively. Secondary breakdown products included cyano(3-hydroxyphenyl)methyl deltamethrate and deltamethric acid. CYP6M2 was most highly transcribed in the midgut and Malpighian tubules of adult A. gambiae, consistent with a role in detoxification. Our data indicates that CYP6M2 plays an important role in metabolic resistance to pyrethroids and thus an important target for the design of new tools to combat malaria.

Pathogenomics of Culex quinquefasciatus and meta-analysis of infection responses to diverse pathogens

The mosquito Culex quinquefasciatus poses a substantial threat to human and veterinary health as a primary vector of West Nile virus (WNV), the filarial worm Wuchereria bancrofti, and an avian malaria parasite. Comparative phylogenomics revealed an expanded canonical C. quinquefasciatus immune gene repertoire compared with those of Aedes aegypti and Anopheles gambiae. Transcriptomic analysis of C. quinquefasciatus genes responsive to WNV, W. bancrofti, and non-native bacteria facilitated an unprecedented meta-analysis of 25 vector-pathogen interactions involving arboviruses, filarial worms, bacteria, and malaria parasites, revealing common and distinct responses to these pathogen types in three mosquito genera. Our findings provide support for the hypothesis that mosquito-borne pathogens have evolved to evade innate immune responses in three vector mosquito species of major medical importance.

Towards a genetic map for Anopheles albimanus: identification of microsatellite markers and a preliminary linkage map for chromosome 2

Fifty microsatellite loci were identified in the malaria vector Anopheles albimanus. Markers segregating in F2 progeny of crosses between laboratory strains of An. albimanus were used to construct a preliminary genetic map. More than 300 progeny were genotyped, but the resolution of the map was limited by the lack of polymorphisms in the microsatellite alleles. A robust linkage map for chromosome 2 was established, and additional markers were assigned to the third and X chromosomes by linkage to morphological markers of known physical location. Additional non-informative microsatellite sequences are provided including some showing similarity to those of An. gambiae. This study significantly increases the number of genetic markers available for An. albimanus and provides useful tools for population genetics and genetic mapping studies in this important malaria vector.

Clinical trial: low plasma cholesterol and oxidative stress predict rapid virological response to standard therapy with peginterferon and ribavirin in HCV patients

BACKGROUND

Rapid virological response (RVR) is the best predictor of sustained response to standard HCV treatment.

AIM

To evaluate predictive factors of RVR.

METHODS

Sixty-five patients (mean age 52.6 +/- 13.8; 37 genotype-1, and 28 genotypes-2/3) were consecutively treated with pegIFN-alpha 2a or 2b once weekly plus daily ribavirin based on body weight for 24 or 48 weeks, according to genotype. RVR was defined as undetectable HCV-RNA at week 4.

RESULTS

Twenty-seven percent of patients achieved RVR in genotypes 1 and 60.7% in genotypes 2/3 (P < 0.01). Rapid responders had higher mean serum baseline total and LDL-cholesterol levels (P < 0.01). RVR was 20.0% in the bottom tertile of total cholesterol and 63.6% in the top tertile (P < 0.01). HCV-RNA levels at week 4 were positively correlated with baseline serum insulin (P < 0.01), HOMA-IR (P < 0.01), body mass index (P < 0.05) and number of components of metabolic syndrome (P < 0.01) and negatively correlated with cholesterol levels (P < 0.05). At multivariate analysis, age, LDL-cholesterol, HCV genotype and serum 8-iso-PGF 2 alpha, a marker of oxidative stress, were independent predictors of RVR.

CONCLUSIONS

Our prospective study supports a role of low serum total and LDL-cholesterol and of oxidative stress as positive independent predictive factors of poor RVR in HCV patients.

Effects on platelet function of combination etoposide and carboplatin chemotherapy in pediatric oncology patients

The effects of a therapeutic course of the combination of carboplatin and etoposide on platelet function have been evaluated in 10 pediatric patients with brain tumors. Platelet count, in vitro aggregation tests, P-selectin expression and agonist-induced ATP release were evaluated before, and 7 and 15 days after one cycle of chemotherapy. The analysis of the results demonstrated the presence of an in vitro platelet aggregation defect in response to collagen and arachidonic acid in all patients 7 days after therapy. A concomitant decrease of collagen- and arachidonic acid-induced ATP release was also observed. Both platelet aggregation and ATP release returned to baseline values 15 days after chemotherapy administration. Conversely, in vitro platelet aggregation and secretion induced by ADP and epinephrine were unaltered by carboplatin and etoposide administration. Furthermore, P-selectin expression was negative at baseline and did not change after chemotherapy. These results support the hypothesis that combination etoposide and carboplatin chemotherapy in pediatric patients is responsible for possible disturbances in biochemical pathways required for platelet secretion and aggregation.