Viral hepatitis and anti-phospholipid antibodies positivity: A systematic review and meta-analysis

Lipid-binding antiphospholipid antibodies: significance for pathophysiology and diagnosis of the antiphospholipid syndrome

The antiphospholipid syndrome (APS) is an autoimmune disease characterized by the presence of pathogenic antiphospholipid antibodies (aPL). Since approximately 30 years ago, lipid-binding aPL, which do not require a protein cofactor, have been regarded as irrelevant for APS pathogenesis even though anticardiolipin are a diagnostic criterion of APS. In this review, we will summarize the available evidence from in vitro studies, animal models, and epidemiologic studies, which suggest that this concept is no longer tenable. Accordingly, we will only briefly touch on the role of other aPL in APS. This topic has been amply reviewed in detail elsewhere. We will discuss the consequences for laboratory diagnostics and future research required to resolve open questions related to the pathogenic role of different aPL specificities.

Map of thrombogenesis in viral infections and viral-driven tumours

Viruses are pathogenic agents responsible for approximately 10% of all human cancers and significantly contribute to the global cancer burden. Until now, eight viruses have been associated with the development of a broad range of malignancies, including solid and haematological tumours. Besides triggering and promoting oncogenesis, viral infections often go hand-in-hand with haemostatic changes, representing a potential risk factor for venous thromboembolism (VTE). Conversely, VTE is a cardiovascular condition that is particularly common among oncological patients, with a detrimental impact on patient prognosis. Despite an association between viral infections and coagulopathies, it is unclear whether viral-driven tumours have a different incidence and prognosis pattern of thromboembolism compared to non-viral-induced tumours. Thus, this review aims to analyse the existing evidence concerning the association of viruses and viral tumours with the occurrence of VTE. Except for hepatitis C virus (HCV) and human immunodeficiency virus (HIV) infection, which are associated with a high risk of VTE, little evidence exists concerning the thrombogenic potential associated with oncoviruses. As for tumours that can be induced by oncoviruses, four levels of VTE risk are observed, with hepatocellular carcinoma (HCC) and gastric carcinoma (GC) associated with the highest risk and nasopharyngeal carcinoma (NPC) associated with the lowest risk. Unfortunately, the incidence of cancer-related VTE according to tumour aetiology is unknown. Given the negative impact of VTE in oncological patients, research is required to better understand the mechanisms underlying blood hypercoagulability in viral-driven tumours to improve VTE management and prognosis assessment in patients diagnosed with these tumours.

Pathogenic lipid-binding antiphospholipid antibodies are associated with severity of COVID-19

BACKGROUND

Coronavirus disease 19 (COVID-19)-associated coagulopathy is a hallmark of disease severity and poor prognosis. The key manifestations of this prothrombotic syndrome-microvascular thrombosis, stroke, and venous and pulmonary clots-are also observed in severe and catastrophic antiphospholipid syndrome. Antiphospholipid antibodies (aPL) are detectable in COVID-19 patients, but their association with the clinical course of COVID-19 remains unproven.

OBJECTIVES

To analyze the presence and relevance of lipid-binding aPL in hospitalized COVID-19 patients.

METHODS

Two cohorts of 53 and 121 patients from a single center hospitalized for PCR-proven severe acute respiratory syndrome-coronavirus 2 infection were analyzed for the presence of aPL and clinical severity of COVID-19.

RESULTS

We here demonstrate that lipid-binding aPL are common in COVID-19. COVID-19 patients with lipid-binding aPL have higher median concentrations of C-reactive protein and D-dimer, and are more likely to have a critical clinical course and fatal outcome. Lipid-binding aPL isolated from COVID-19 patients target the recently described cell surface complex of lysobisphosphatidic acid (LBPA) with the protein C receptor (EPCR) to induce prothrombotic and inflammatory responses in monocytes and endothelial cells. We show that B1a cells producing lipid-reactive aPL of the IgG isotype circulate in the blood of COVID-19 patients. In vivo, COVID-19 aPL accelerate thrombus formation in an experimental mouse model dependent on the recently delineated signaling pathway involving EPCR-LBPA.

CONCLUSIONS

COVID-19 patients rapidly expand B1a cells secreting pathogenic lipid-binding aPL with broad thrombotic and inflammatory effects. The association with markers of inflammation and coagulation, clinical severity, and mortality suggests a causal role of aPL in COVID-19-associated coagulopathy.

Antiphospholipid antibodies in critically ill COVID-19 patients with thromboembolism: cause of disease or epiphenomenon?

Coronavirus 2019 disease (COVID-19) is associated with coagulation dysfunction that predisposes patients to an increased risk for both arterial (ATE) and venous thromboembolism (VTE) and consequent poor prognosis; in particular, the incidence of ATE and VTE in critically ill COVID-19 patients can reach 5% and 31%, respectively. The mechanism of thrombosis in COVID-19 patients is complex and still not completely clear. Recent literature suggests a link between the presence of antiphospholipid antibodies (aPLs) and thromboembolism in COVID-19 patients. However, it remains uncertain whether aPLs are an epiphenomenon or are involved in the pathogenesis of the disease.

Perspective - The case for zero bleeds and drug bioequivalence in the treatment of congenital hemophilia A in 2021

Not all patients with severe hemophilia A (HA) respond optimally to a given dose of a given product. Within-individual variance in cross-over studies makes each patient unique in the response to each standard half-life (SHL) factor VIII (FVIII) product in pharmacokinetic (PK) terms. This hampers the prediction of efficacy when a SHL FVIII product is employed. PK data showing that half-lives of SHL rFVIII are unsatisfactory to achieve zero bleeding in individual HA patients provide the rationale for switching from SHL to extended half-life (EHL) products. However, not all subjects receiving prophylaxis with EHL products achieve zero bleeding, the most cogent objective of personalized prophylaxis. Known determinants of FVIII half-life (age, von Willebrand factor [VWF] levels, blood group) cumulatively account for one third of the total inter-individual variation in FVIII clearance in subjects with severe HA. Investigations into precision, and accuracy of laboratory measurement to be employed; newer pathways for the clearance of both free-FVIII and VWF-bound FVIII, and adequately powered studies on omics and phenotypic heterogeneity, are likely to provide additional information on the remaining two thirds of inter-individual variation in FVIII clearance in HA. Variability in the clinical response has also been documented in patients when FVIII activity is mimicked by fixed subcutaneous doses of the bispecific antibody emicizumab. National registries that collect PK data of available FVIII products and ad hoc information on the individual response to emicizumab should be encouraged, to establish newer standards of care and ease personalized clinical decisions to achieve zero bleeding.

Association of systemic lupus erythematosus with peripheral arterial disease: a meta-analysis of literature studies

OBJECTIVE

SLE patients have an increased cardiovascular morbidity and mortality. Contrasting data are available about the association between peripheral arterial disease (PAD) and SLE. We aimed to perform a meta-analysis of studies evaluating the association between SLE and PAD.

METHODS

Studies were systematically searched in the PubMed, Web of Science, Scopus and EMBASE databases according to preferred reporting items for systematic reviews and meta-analyses guidelines.

RESULTS

Eight studies reporting on 263 258 SLE patients and 768 487 controls showed that the prevalence of PAD was 15.8% (95% CI: 10.5%, 23.2%) in SLE patients and 3.9% (95% CI: 1.8%, 7.9%) in controls with a corresponding odds ratio of 4.1 (95% CI: 1.5, 11.6; P <0.001). In addition, five studies reporting on ankle-brachial index showed significantly lower values in 280 SLE patients as compared with 201 controls (mean difference: -0.018; 95% CI: -0.034, -0.001; P =0.033). Meta-regression models showed that age, hypertension and diabetes were inversely associated with the difference in the prevalence of PAD between SLE patients and non-SLE controls, whereas no effect for all the other clinical and demographic variables on the evaluated outcome was found.

CONCLUSION

SLE patients exhibit an increased prevalence of PAD and lower ankle-brachial index values as compared with non-SLE controls. This should be considered when planning prevention, interventional and rehabilitation strategies for these chronic patients with functional disability and poor long-term outcomes.

Paradigm shift for the treatment of hereditary haemophilia: Towards precision medicine

Patients with haemophilia A (HA) or B (HB) experience spontaneous limb- or life-threatening bleedings which are prevented by regular prophylactic intravenous infusions of the deficient coagulation factor (FVIII or FIX). Prophylaxis with subcutaneous long-acting non-factor products that improve in vivo thrombin generation is now under intensive investigation (concizumab, fitusiran) or successfully employed (emicizumab) in haemophilia patients. Both haemophilia patients with/without inhibitors take advantage of non-factor products employed alone. In those who also need bypassing agents (or FVIII concentrates) for breakthrough bleeds, thromboembolic events and/or thrombotic microangiopathy may occur. By enhancing thrombin generation, prothrombotic mutations co-segregating with FVIII/FIX gene mutations may trigger thrombotic episodes in HA patients carrying acquired thrombogenic factors (e.g. venous catheters). A thorough knowledge of individual needs increasingly contributed to improve comprehensive care and personalize treatments in haemophilia. Integrating genomics, lifestyle and environmental data is expected to be key to: 1) identify which haemophilia patients are less likely to benefit from a given intervention; 2) define optimal dosing and scheduling of bypassing agents (or FVIII) to employ in combination with non-factor products; 3) establish tests to monitor in vivo thrombin generation; 4) improve communication and deliver results to individuals. As individual outcomes will be improved and the risk of adverse events minimized, non-factor products will come into wider use within the haemophilia community, and patients will hopefully have no more risks of breakthrough bleeds. The risks of a normal life for a "former haemophilia patient" is likely to change the treatment landscape and the structure of haemophilia Centers.

Infections: a double-edge sword in autoimmunity

PURPOSE OF REVIEW

Infections play a role in the pathogenesis of autoimmune diseases (AID). Several bacterial and viral pathogens play a double role, as both inducers and inhibitors of AID. In this review, we will present current evidence and discuss different aspects of this notion.

RECENT FINDINGS

Infectors that both inhibit and induce AID include Helicobacter pylori, Klebsiella pneumoniae, hepatitis B virus, group B Coxsackieviruses, Epstein-Barr virus and Lymphocytic choriomeningitis virus. Numerous AID are affected by infections, including polyarteritis nodosa, inflammatory bowel disease, and type 1 diabetes. Some pathogens, such as group B Coxsackieviruses, may induce and inhibit the development of the same AID. This reveals a complex role of infections in autoimmunity pathogenesis.

SUMMARY

Elucidating the exact role of each pathogen on each specific AID is important, as this will enable evaluating the manipulation of these infections in the treatment of AID.

Prevalence of Antiphospholipid Antibody Positivity and Association of Pretransplant Lupus Anticoagulant Positivity With Early Allograft Dysfunction in Liver Transplantation

BACKGROUND

Antiphospholipid antibodies (aPL), including anticardiolipin (aCL), anti-β₂-glycoprotein I (anti-β2GPI), and lupus anticoagulant (LA) antibodies, are frequently found in liver cirrhosis and associated with splanchnic vein thrombosis. Although the risk factors of early allograft dysfunction (EAD) are known, the association between EAD and aPL has been poorly investigated. We hypothesized that LA, potent aPL with thrombotic potential, may be associated with EAD development after living donor liver transplantation (LDLT).

METHODS

Data of 719 patients who underwent LDLT from February 2014 to June 2016 at our center were retrospectively collected and analyzed. Patients were divided into 2 groups according to the positivity of LA screening test (LA group [n = 148] vs no-LA group [n = 571]). Risk factors for EAD were investigated using multivariable regression analysis and inverse probability of treatment weighting (IPTW) of propensity scores.

RESULTS

The prevalence of LA screening positivity, confirmatory test positivity, and EAD was 20.6%, 1.1%, and 11.3%, respectively. aCL positivity rate was 7.5% and anti-β2GPI positivity rate was 7.0%. The EAD prevalence in LA and no-LA group was 25.7% and 7.5%, respectively. However, multivariable and IPTW analyses showed no association between EAD and LA screening positivity (P = .263 and P = .825, respectively), although a significant association was found in univariate analysis (odds ratio, 4.242; P < .001). Model for End-stage Liver Disease score, operation time, and C-reactive protein level remained significant after multivariable analysis.

CONCLUSION

A positive LA screening test result was associated with EAD only in the univariate analysis. Inflammation, based on C-reactive protein level, was more important for EAD development.

Role of Infectious Diseases in the Antiphospholipid Syndrome (Including Its Catastrophic Variant)

PURPOSE OF REVIEW

The antiphospholipid syndrome (APS) is characterized by the development of thrombotic events and pregnancy morbidity in the presence of antiphospholipid antibodies (aPL). An infectious etiology for this syndrome has been postulated. The present review is aimed to summarize recent evidence about the role of infections and vaccines in the pathogenesis of the APS (including its catastrophic variant).

RECENT FINDINGS

There is an increased risk of developing aPL in various infections, particularly in viral infections. The most frequent infection related to aPL has been hepatitis C virus. These antibodies may be associated with thromboembolic events, including catastrophic APS. There is a link between vaccinations, such as the tetanus toxoid and aPL, due to molecular mimicry between the two molecules. Accumulated evidence supports that the presence of aPL is associated with a variety of infections, including viruses, bacteria, fungi, and parasites, and the main mechanism to explain this correlation is molecular mimicry. Moreover, a link between vaccinations, such as the tetanus toxoid, and APS has also been described.

Direct-acting antiviral drugs for chronic hepatitis C and risk of major vascular events: a systematic review

Direct-acting antiviral drugs (DAAs) were recently approved for treating hepatitis C virus-related chronic hepatitis. As advanced chronic liver disease may predispose patients to thrombotic events, it is still uncertain whether DAAs may influence the actual risk of major arterial and venous thrombotic events. We performed a systematic review to assess the incidence of major vascular events in patients receiving DAAs for HCV chronic hepatitis during phase-III randomized controlled trials (RCTs). Two reviewers identified studies through Pubmed database until October 2015. Reporting and incidence of any vascular events were compared with reporting and incidence of major bleeding, anemia (a prespecified safety outcome) and headache (a common non-prespecified safety outcome). 33 RCTs, encompassing 14,764 patients, were included. Only 13 (39%) and 4 (12%) RCTs provide data on any arterial or venous events, respectively. Occurrence of anemia and headache is reported in all studies. Crude unweighted rate of major arterial events is 0.16% (95% CI 0.10-0.24) of the total included population and 0.47% in those 13 RCTs reporting data. Crude unweighted rate of major venous events is 0.03% of the total included population (95% CI 0.01-0.08) and 0.22% in those four RCTs reporting data. Crude unweighted rate of major bleeding is 0.07% (95% CI 0.03-0.1). Incidence of thrombotic events in HCV patients receiving DAAs may be low, but an incorrect estimation cannot be excluded.

Dysregulated CD25 and Cytokine Expression by γδ T Cells of Systemic Sclerosis Patients Stimulated With Cardiolipin and Zoledronate

Objectives

γδ T cells, a non-conventional innate lymphocyte subset containing cells that can be activated by lipids and phosphoantigens, are abnormally regulated in systemic sclerosis (SSc). To further evaluate the significance of this dysregulation, we compared how exposure to an autoantigenic lipid, cardiolipin (CL), during co-stimulation with an amino-bisphosphonate (zoledronate, zol), affects the activation and cytokine production of SSc and healthy control (HC) γδ T cells.

Methods

Expression of CD25 on Vγ9⁺, Vδ1⁺, and total CD3⁺ T cells in cultured peripheral blood mononuclear cells (PBMCs), their binding of CD1d tetramers, and the effect of monoclonal antibody (mAb) blockade of CD1d were monitored by flow cytometry after 4 days of in vitro culture. Intracellular production of IFNγ and IL-4 was assessed after overnight culture.

Results

Percentages of CD25⁺ among CD3⁺ and Vδ1⁺ T cells were elevated significantly in short-term cultured SSc PBMC compared to HC. In SSc but not HC, CL and zol, respectively, suppressed %CD25⁺ Vγ9⁺ and Vδ1⁺ T cells but, when combined, CL + zol significantly activated both subsets in HC and partially reversed inhibition by the individual reagents in SSc. Importantly, Vδ1⁺ T cells in both SSc and HC were highly reactive with lipid presenting CD1d tetramers, and a CD1d-blocking mAb decreased CL-induced enhancement of %SSc CD25⁺ Vδ1⁺ T cells in the presence of zol. %IFNγ⁺ cells among Vγ9⁺ T cells of SSc was lower than HC cultured in medium, CL, zol, or CL + zol, whereas %IFNγ⁺ Vδ1⁺ T cells was lower only in the presence of CL or CL + zol. %IL-4⁺ T cells were similar in SSc and HC in all conditions, with the exception of being increased in SSc Vγ9⁺ T cells in the presence of CL.

Conclusion

Abnormal functional responses of γδ T cell subsets to stimulation by CL and phosphoantigens in SSc may contribute to fibrosis and immunosuppression, characteristics of this disease.

The risk of venous thromboembolism in patients with hepatitis C

Some studies suggest that patients with hepatitis C virus (HCV) infection have an increased risk of deep venous thrombosis (DVT) and pulmonary embolism (PE). Unfortunately, available data on this association are contrasting. A systematic review and meta-analysis of literature studies was performed to evaluate the risk of venous thromboembolism (VTE) associated with HCV. Studies reporting on VTE risk associated with HCV were systematically searched in the PubMed, Web of Science, Scopus and EMBASE databases. Six studies (10 data-sets) showed a significantly increased VTE risk in 100,364 HCV patients as compared with 8,471,176 uninfected controls (odds ratio [OR]: 1.900; 95 % confidence interval [CI]: 1.406, 2.570; p<0.0001). These results were confirmed when specifically considering the risk of DVT (6 studies, OR: 1.918; 95 %CI: 1.351, 2.723; p<0.0001), whereas a trend towards an increased risk of PE was documented in HCV patients (4 studies, OR: 1.811; 95 %CI: 0.895, 3.663; p=0.099). The increased VTE risk associated with HCV infection was consistently confirmed when analysing four studies reporting adjusted risk estimates (OR: 1.876; 95 %CI: 1.326, 2.654; P<0.0001), and after excluding studies specifically enrolling populations exposed to transient risk factors for VTE (4 studies, OR: 1.493; 95 %CI: 1.167, 1.910; p=0.001). Meta-regression models suggested that age and male gender may significantly impact on the risk of VTE associated with HCV-positivity. Results of our metaanalysis suggest that HCV-infected subjects may exhibit an increased risk of VTE. However, further high quality studies are needed to extend and confirm our findings.

Supplementary Material to this article is available online at www.thrombosis-online.com.

Diagnostic accuracy of tests to detect Hepatitis C antibody: a meta-analysis and review of the literature

BACKGROUND

Although direct-acting antivirals can achieve sustained virological response rates greater than 90% in Hepatitis C Virus (HCV) infected persons, at present the majority of HCV-infected individuals remain undiagnosed and therefore untreated. While there are a wide range of HCV serological tests available, there is a lack of formal assessment of their diagnostic performance. We undertook a systematic review and meta-analysis to evaluate he diagnostic accuracy of available rapid diagnostic tests (RDT) and laboratory based EIA assays in detecting antibodies to HCV.

METHODS

We used the PRISMA checklist and Cochrane guidance to develop our search protocol. The search strategy was registered in PROSPERO (CRD42015023567). The search focused on hepatitis C, diagnostic tests, and diagnostic accuracy within eight databases (MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, Science Citation Index Expanded, Conference Proceedings Citation Index-Science, SCOPUS, Literatura Latino-Americana e do Caribe em Ciências da Saúde and WHO Global Index Medicus. Studies were included if they evaluated an assay to determine the sensitivity and specificity of HCV antibody (HCV Ab) in humans. Two reviewers independently extracted data and performed a quality assessment of the studies using the QUADAS tool. We pooled test estimates using the DerSimonian-Laird method, by using the software R and RevMan. 5.3.

RESULTS

A total of 52 studies were identified that included 52,673 unique test measurements. Based on five studies, the pooled sensitivity and specificity of HCV Ab rapid diagnostic tests (RDTs) were 98% (95% CI 98-100%) and 100% (95% CI 100-100%) compared to an enzyme immunoassay (EIA) reference standard. High HCV Ab RDTs sensitivity and specificity were observed across screening populations (general population, high risk populations, and hospital patients) using different reference standards (EIA, nucleic acid testing, immunoblot). There were insufficient studies to undertake subanalyses based on HIV co-infection. Oral HCV Ab RDTs also had excellent sensitivity and specificity compared to blood reference tests, respectively at 94% (95% CI 93-96%) and 100% (95% CI 100-100%). Among studies that assessed individual oral RDTs, the eight studies revealed that OraQuick ADVANCE® had a slightly higher sensitivity (98%, 95% CI 97-98%) compared to the other oral brands (pooled sensitivity: 88%, 95% CI 84-92%).

CONCLUSIONS

RDTs, including oral tests, have excellent sensitivity and specificity compared to laboratory-based methods for HCV antibody detection across a wide range of settings. Oral HCV Ab RDTs had good sensitivity and specificity compared to blood reference standards.

Risk of developing antiphospholipid antibodies following viral infection: a systematic review and meta-analysis

Objective The objective of this paper is to conduct a systematic review and meta-analysis on the risk of developing elevated antiphospholipid (aPL) antibodies and related thromboembolic and/or pregnancy events following a viral infection. Method We searched Medline, EMBASE, Web of Science, PubMed ePubs, and Cochrane Central Register of Controlled Trials through June 2016. Independent observational studies of elevated aPL antibodies in patients with a viral infection compared with controls or patients with lupus were included. Results We analyzed 73 publications for 60 studies. Human immunodeficiency virus (HIV) and hepatitis C virus (HCV) were most commonly reported. Compared with healthy controls, patients with HIV were more likely to develop elevated anticardiolipin (aCL) antibodies (risk ratio (RR) 10.5, 95% confidence interval (CI) 5.6-19.4), as were those with HCV (RR 6.3, 95% CI 3.9-10.1), hepatitis B virus (HBV) (RR 4.2, 95% CI 1.8-9.5), and Epstein-Barr virus (EBV) (RR 10.9 95% CI 5.4-22.2). The only statistically significant increased risk for anti-β2-glycoprotein I (anti-β2-GPI) antibodies was observed in patients with HCV (RR 4.8 95% CI 1.0-22.3). Compared with patients with lupus, patients with HIV were more likely to develop elevated aCL antibodies (RR 1.8, 95% CI 1.3-2.6), and those with EBV, elevated anti-β2-GPI antibodies (RR 2.2, 95% CI 1.3-3.9). Thromboembolic events were most prevalent in patients with elevated aPL antibodies who had HCV (9.1%, 95% CI 3.0-18.1), and HBV (5.9%, 95% CI 2.0-11.9) infections, and pregnancy events were most prevalent in those with parvovirus B19 (16.3%, 95% CI 0.78-45.7). However, compared to virus-infected patients with negative aPL antibodies, the only statistically significant increased risk was observed in those with HCV and positive aPL. Conclusions Viral infection can increase the risk of developing elevated aPL antibodies and associated thromboembolic events. Results are contingent on the reported information.

Subclinical carotid atherosclerosis in patients with chronic obstructive pulmonary disease: a meta-analysis of literature studies

BACKGROUND

Chronic obstructive pulmonary disease (COPD) patients have an increased cardiovascular (CV) morbidity and mortality. Common carotid intima-media thickness (CCA-IMT) and carotid plaques are surrogate markers of subclinical atherosclerosis and predictors of CV events.

METHODS AND RESULTS

We performed a meta-analysis to evaluate the association between COPD and subclinical atherosclerosis. Studies evaluating the impact of COPD on CCA-IMT and on the prevalence of carotid plaques were systematically searched.

RESULTS

Twenty studies (2082 COPD patients and 4844 controls) were included, 12 studies with data on CCA-IMT (13 data-sets on 1180 COPD patients and 2312 controls) and 12 studies reporting on the prevalence of carotid plaques (1231 COPD patients and 4222 controls). Compared to controls, COPD patients showed a significantly higher CCA-IMT (mean difference [MD]: 0.201 mm; 95%CI: 0.142, 0.260; p < .001), and an increased prevalence of carotid plaques (Odds Ratio [OR]: 2.503; 95%CI: 1.333, 2.175; p < .0001). Meta-regression models showed a direct association between disease severity [as expressed by Global Initiative for Chronic Obstructive Lung Disease (GOLD) class] and the difference in the risk of carotid plaques presence between COPD patients and controls.

CONCLUSIONS

COPD is significantly associated with subclinical atherosclerosis. These findings may be useful to plan adequate CV prevention strategies. Key messages COPD patients show a higher CCA-IMT and an increased prevalence of carotid plaques compared with controls. A more severe pulmonary disease is associated with a higher prevalence of carotid plaques in COPD patients. Screening for subclinical atherosclerosis may be worthy in COPD patients to plan specific prevention strategies.

Clinical assessment of endothelial function in patients with chronic obstructive pulmonary disease: a systematic review with meta-analysis

Patients with chronic obstructive pulmonary disease (COPD) have an increased cardiovascular morbidity and mortality. Flow-mediated (FMD) and nitrate-mediated dilatation (NMD) are considered non-invasive methods to assess endothelial function and surrogate markers of subclinical atherosclerosis. We performed a systematic review with meta-analysis and meta-regression to evaluate the impact of COPD on FMD and NMD. Studies were systematically searched in the PubMed, Web of Science, Scopus and EMBASE databases. The random-effect method was used to take into account the variability among included studies. A total of eight studies were included in the final analysis, eight with data on FMD (334 COPD patients) and two on NMD (104 COPD patients). Compared to controls, COPD patients show a significantly lower FMD (MD -3.15%; 95% CI -4.89, -1.40; P < 0.001) and NMD (MD -3.53%; 95% CI -7.04, -0.02; P = 0.049). Sensitivity analyses substantially confirms the results. Meta-regression models show that a more severe degree of airway obstruction is associated with a more severe FMD impairment in COPD patients than in controls. Regression analyses confirm that the association between COPD and endothelial dysfunction is independent of baseline smoking status and most traditional cardiovascular risk factors. In conclusion, COPD is significantly and independently associated with endothelial dysfunction. These findings may be useful to plan adequate cardiovascular prevention strategies in this clinical setting, with particular regard to patients with a more severe disease.

The risk of venous thromboembolism in patients with cirrhosis. A systematic review and meta-analysis

Some studies suggest that patients with cirrhosis have an increased risk of deep venous thrombosis (DVT) and pulmonary embolism (PE). Unfortunately, available data on this association are contrasting. It was the objective of this study to perform a systematic review and meta-analysis of literature to evaluate the risk of venous thromboembolism (VTE) associated with cirrhosis. Studies reporting on VTE risk associated with cirrhosis were systematically searched in the PubMed, Web of Science, Scopus and EMBASE databases. Eleven studies (15 data-sets) showed a significantly increased VTE risk in 695,012 cirrhotic patients as compared with 1,494,660 non-cirrhotic controls (OR: 1.703; 95 %CI: 1.333, 2.175; P<0.0001). These results were confirmed when specifically considering the risk of DVT (7 studies, OR: 2.038; 95 %CI: 1.817, 2.285; P<0.0001) and the risk of PE (5 studies, OR: 1.655; 95 %CI: 1.042, 2.630; p=0.033). The increased VTE risk associated with cirrhosis was consistently confirmed when analysing nine studies reporting adjusted risk estimates (OR: 1.493; 95 %CI: 1.266, 1.762; p<0.0001), and after excluding studies specifically enrolling populations exposed to transient risk factors for VTE (OR: 1.689; 95 %CI: 1.321, 2.160; p<0.0001). Meta-regression models suggested that male gender may significantly impact on the risk of VTE associated with cirrhosis. Results of our meta-analysis suggest that cirrhotic subjects may exhibit an increased risk of VTE. This should be considered to plan specific prevention strategies in this clinical setting.

Antiphospholipid Antibodies and the Risk of Stroke in Urban and Rural Tanzania: A Community-Based Case-Control Study

BACKGROUND AND PURPOSE

The burden of stroke is high in sub-Saharan Africa, and improved knowledge of risk factors is needed. Antiphospholipid antibodies are a common acquired stroke risk factor in young individuals. Antiphospholipid antibodies may be induced by infectious diseases. Sub-Saharan Africa has a high infectious burden, and we analyzed the contribution of antiphospholipid antibodies to the risk of stroke in an incident population from rural and urban Tanzania.

METHODS

Stroke cases and age- and sex-matched community-acquired controls from the rural Hai district and urban Dar-es-Salaam areas of Tanzania were recruited in a wider study of stroke incidence between June 2003 and June 2006. Lupus anticoagulant, anticardiolipin, anti-β2-glycoprotein I, and antiphosphatidylserine/prothrombin antibodies were determined in stored plasma, as well as IgG antibodies against Treponema pallidum.

RESULTS

Data from 158 stroke cases and 369 controls were analyzed. Thirty cases (19%) and 4 controls (1%) had a lupus anticoagulant (odds ratio, 20.8; 95% confidence interval, 7.2-60.5). Anticardiolipin IgG was the only other antiphospholipid antibody subtype associated with increased stroke risk (odds ratio, 2.1; 95% confidence interval, 1.0-4.3), but this association disappeared when corrected for IgG antibodies against Treponema pallidum results. The prevalence of anti-β2-glycoprotein I IgG antibodies in the Tanzanian healthy population was high when Dutch cutoff values were applied (67%), whereas presence of anti-β2-glycoprotein I IgM was associated with a reduced stroke risk (odds ratio 0.3; 95% confidence interval, 0.1-1.1).

CONCLUSIONS

The presence of lupus anticoagulant is a strong, and to date unrecognized, risk factor for stroke in Tanzania, especially in young and middle-aged individuals.

Significance of fully automated tests for the diagnosis of antiphospholipid syndrome

Antiphospholipid antibodies (aPLs) can vary both immunologically and functionally, thus it is important to effectively and correctly identify their presence when diagnosing antiphospholipid syndrome. Furthermore, since many immunological/functional tests are necessary to measure aPLs, complete examinations are often not performed in many cases due to significant burden on the testing departments. To address this issue, we measured aPLs defined according to the classification criteria (anticardiolipin antibody: aCL) IgG/IgM and anti-β₂ glycoprotein I antibody (aβ₂GPI) (IgG/IgM) as well as non-criteria antibodies (aCL IgA, aβ₂GPI IgA and aβ₂GPI domain I), in a cohort of 211 patients (61 APS, 140 disease controls and 10 healthy individuals). APLs were measured using a fully automated chemiluminescent immunoassay instrument (BIO-FLASH®/ACL AcuStar®) and with conventional ELISA tests. We demonstrated that both sensitivity and accuracy of diagnosis of aCL IgG and aβ₂GPI IgG were high, in agreement with the past reports. When multiple aPLs were examined, the accuracy of diagnosis increased. The proportion of APS patients that were positive for 2 or more types of aPLs (47/61, 77%) was higher than that of patients with systemic lupus erythematosus (SLE)(3/37, 9%), those with non-SLE connective tissues diseases (1/53,2%), those with other diseases or healthy volunteers. Based on these findings, it was concluded that the fully automated chemiluminescent immunoassay instrument, which allows the simultaneous evaluation of many types of aPLs, offers clear advantages for a more complete, more rapid and less labor-intensive alternative to running multiple ELISA and could help in better diagnosis for suspected APS patients.

The risk of coronary artery disease and cerebrovascular disease in patients with hepatitis C: A systematic review and meta-analysis

BACKGROUND/OBJECTIVES

Some studies suggest that patients with hepatitis C virus (HCV) infection have an increased risk of coronary artery disease (CAD) and cerebrovascular disease. Unfortunately, available data on this association are widely variable. We have performed a systematic review and meta-analysis of literature to evaluate the risk of cardio-cerebrovascular disease (CCD) associated with HCV.

METHODS

Studies reporting on CCD risk associated with HCV were systematically searched in the PubMed, Web of Science, Scopus and EMBASE databases.

RESULTS

Twenty-seven studies (34 data-sets) showed a significantly increased CCD risk in 297,613 HCV patients as compared with 557,814 uninfected controls (OR: 1.428; 95% CI: 1.214, 1.681). These results were confirmed when separately considering the risk of CAD (20 studies, OR: 1.382; 95% CI: 1.103, 1.732) and of cerebrovascular disease (13 studies, OR: 1.485; 95% CI: 1.079, 2.044). Similar results were confirmed when analyzing 21 studies reporting adjusted risk estimates (OR: 1.448; 95% CI: 1.218, 1.722) and when, after excluding studies defining CAD as positive angiographic or electrocardiographic evidence, we specifically included the 17 studies reporting on acute CCD-related events (OR: 1.357; 95% CI: 1.103, 1.670). Moreover, 4 studies evaluating CCD-related deaths showed a higher risk in HCV patients than controls (OR: 1.772; 95% CI: 1.448, 2.168; P<0.0001). Meta-regression models suggested a direct association between prevalence of cirrhosis and difference in CCD risk between HCV patients and controls.

CONCLUSIONS

Results of our large meta-analysis suggest that HCV-infected subjects experience an increased risk of CCD. This should be considered to plan specific cardiovascular prevention strategies in this clinical setting.