Antonella Bassi

Introduction: Apolipoprotein C-III (Apo CIII) is a crucial regulator of triglyceride-rich lipoproteins (TRLs) and influences the risk of cardiovascular diseases. High levels of Apo CIII have been also associated with cerebrovascular events and earlier works showed procoagulant effects of Apo CIII. The main aim was to assess whether the plasma concentration of Apo CIII could confer an increased risk of cerebral ischemic events in anticoagulated patients at high-risk of cardioembolism.Methods: We systematically checked medical records and quantified cerebral ischemic events in a selected cohort of 118 subjects [median age 68 with interquartile range (IQR) 59–75 years, 66.9% males, 52.5% with coronary artery disease (CAD)], taking anticoagulant therapy with warfarin because of atrial fibrillation (AF) and/or mechanical prosthetic heart valves. All the subjects, enrolled between May 1999 and December 2006, were prospectively followed until death or July 31, 2018. Assessments of complete plasma lipid and apolipoprotein profiles, including Apo A-I, B, CIII, and E, were available for all subjects at enrollment.Results: After a median follow-up of 109 months (IQR, 58–187), 24 subjects (20.3%) had cerebral ischemic events: stroke (n = 15) and TIA (n = 9). Subjects with plasma concentration of Apo CIII above the median value (10.3 mg/dL) had an about three-fold increased risk of stroke/TIA than those with lower levels of Apo C-III [hazard ratio 3.08 (95%CI, 1.22–7.77)]. This result was confirmed in multiple Cox regression models adjusted for gender, age, CAD, AF, diabetes, hypertension, plasma lipids, and CHA₂DS₂-VASc score. By stratifying the sample on the basis of Apo CIII level and CHA₂DS₂-VASc score, an additive effect was observed with the highest risk in subjects with both high Apo C-III concentration and CHA₂DS₂-VASc score.Conclusion: High Apo CIII plasma levels may be associated with an increased risk of ischemic stroke/TIA in high-risk cardiovascular patients anticoagulated with warfarin.

Background: To report the baseline phase of the SIEROEPID study on SARS-CoV-2 infection seroprevalence among health workers at the University Hospital of Verona, Italy, between spring and fall 2020; to compare performances of several laboratory tests for SARS-CoV-2 antibody detection. Methods: 5299 voluntary health workers were enrolled from 28 April 2020 to 28 July 2020 to assess immunological response to SARS-CoV-2 infection throughout IgM, IgG and IgA serum levels titration by four laboratory tests. Association of antibody titre with several demographic variables, swab tests and performance tests (sensitivity, specificity, and agreement) were statistically analyzed. Results: The overall seroprevalence was 6%, considering either IgG and IgM, and 4.8% considering IgG. Working in COVID-19 Units was not associated with a statistically significant increase in the number of infected workers. Cohen’s kappa of agreement between MaglumiTM and VivaDiagTM was quite good when considering IgG only (Cohen’s kappa = 78.1%, 95% CI 74.0–82.0%), but was lower considering IgM (Cohen’s kappa = 13.3%, 95% CI 7.8–18.7%). Conclusion: The large sample size with high participation (84.7%), the biobank and the longitudinal design were significant achievements, offering a baseline dataset as the benchmark for risk assessment, health surveillance and management of SARS-CoV-2 infection for the hospital workforce, especially considering the ongoing vaccination campaign. Study results support the national regulator guidelines on using swabs for SARS-CoV-2 screening with health workers and using the serological tests to contribute to the epidemiological assessment of the spread of the virus.

Background: Apolipoprotein CIII (apo CIII ) is a crucial player in triglyceride‐rich lipoprotein metabolism, but may also act pleiotropically, provoking inflammatory responses and stimulating coagulation. Elevated apo CIII plasma levels have been associated with increased activity of coagulation factors. Since these features of prothrombotic diathesis are linked with venous thromboembolism ( VTE ), we hypothesized that apo CIII plays a role in VTE . Methods and Results: We recorded nonfatal VTE events in 1020 patients (age 63.3±11.4 years; 29.1% women) with or without coronary artery disease (79.1% with coronary artery disease and 20.9% without coronary artery disease) during a long follow‐up. Complete plasma lipid and apolipoproteins were available for all patients. Forty‐five patients (4.4%) experienced nonfatal VTE events during a median follow‐up period of 144 months. Apo CIII plasma concentration at enrollment was higher in patients with VTE compared with patients without VTE (12.2 [95% CI, 11.10–13.5] mg/dL vs 10.6 [95% CI, 10.4–10.9] mg/dL, respectively; P =0.011). Patients with apo CIII levels above the median value (10.6 mg/dL) exhibited an increased risk of VTE (incidence rate, 6.0 [95% CI , 4.0–8.0] vs 1.8 [95% CI, 0.7–2.9] VTE events/1000 person‐years; unadjusted hazard ratio [ HR ], 3.42 [95% CI , 1.73–6.75]; P P =0.007]), with inclusion of lipid parameters in the Cox model (HR, 3.74; 95% CI , 1.24–11.33 [ P =0.019]), and even with exclusion of patients who died at follow‐up ( HR, 3.92; 95% CI , 1.68–9.14 [ P =0.002]) or patients taking anticoagulants ( HR , 3.39; 95% CI , 1.72–6.69 [ P <0.001]). Conclusions: Our results suggest that high plasma apo CIII concentrations may predict an increased risk of VTE in patients with cardiovascular disease.

Purpose: The present research reports the study the of plasma proteome profile of stable coronary artery disease (CAD) patients characterized by different levels of total Apolipoprotein‐CIII (Apo C‐III), a prognostic marker for cardiovascular risk.Experimental design: Two subgroups of CAD patients (n = 52) with divergent concentrations of total circulating Apo C‐III (≤ and ≥10 mg dL⁻¹) are examined using a shotgun proteomic approach. Validation experiments are also performed with immunochemistry methods including both the patients affected by CAD (n = 119) and the subjects without CAD (CAD‐free;n = 58). Results are analyzed by bioinformatics tools and multivariate statistics.Results: A total of 188 proteins are quantified among the patients. The fold change analysis and the partial least square discriminant analysis show a clear separation of the two groups. Lipoproteins (Apo C‐II and Apo E), retinol‐binding protein 4, and vitronectin are upregulated in patients with high Apo C‐III, while alpha‐1 antitrypsin is downregulated.Conclusions and clinical relevance: In this pilot study, the differential expression of plasma proteins related to different concentrations of Apo C‐III is defined, suggesting possible new players involved in the Apo C‐III‐associated process of arterial damage. Data are available via ProteomeXchange with identifier PXD005973.

Background: Apolipoprotein C-III (ApoC-III), a key regulator of plasma triglyceride (TG), is present in three isoforms, i.e. non-sialylated (ApoC-III0), monosialylated (ApoC-III1) and disialylated (ApoC-III2). We aimed at quantifying the distribution of the ApoC-III glycoforms in patients with angiographically demonstrated coronary artery disease (CAD) according to levels of total ApoC-III plasma concentration. Methods: ApoC-III glycoforms were quantified by a specifically developed, high-resolution, mass spectrometry method in unrelated CAD patients. Lipoprotein lipase (LPL) activity was estimated by a fluorescence-based method. Results: In 101 statin-treated CAD patients, the absolute concentrations of the three glycoforms similarly increased across ApoC-III quartiles, but the proportion of ApoC-III1 rose whereas that of ApoC-III0 decreased progressively by increasing total ApoC-III concentrations. The proportion of ApoC-III2 was quite constant throughout the whole range of total ApoC-III. A higher proportion of ApoC-III1 reflected an unfavorable lipid profile characterized by high levels of TG, total and low density lipoprotein cholesterol, ApoE and reduced ApoA-I. The correlations between ApoC-III glycoforms and TG were confirmed in 50 statin-free CAD patients. High concentration of total ApoC-III was associated with low LPL activity, while no correlation was found for the relative proportion of glycoforms. Conclusions: Specific patterns of ApoC-III glycoforms are present across different total ApoC-III concentrations in CAD patients. The inhibitory effect of ApoC-III on LPL appears related to total ApoC-III concentration, but not to the relative proportion of ApoC-III glycoforms.

Background: Despite the importance of manual pipetting of fluids such as water, solutions, buffers, reagents, or biological samples in daily laboratory practice, the intra- and inter-individual imprecision of this activity has not been recently described in scientific publications.Methods: Twenty laboratory operators were randomly enrolled for this study. Imprecision of manual pipetting was estimated by asking each laboratory professional to dispense 1 mL, 100 μL or 10 μL of distilled water for 10 consecutive times with three certified pipettes into a 50-mL plastic container placed into a gravimetric balance. The weight of the water dispensed was systematically recorded for each of the 10 repeated attempts, and the inter- and intra-operator imprecision was finally calculated and expressed as coefficient of variation (CV%).Results: The mean intra-individual imprecision was 5.7% (range, 0%–11.8%) for pipetting 10 μL, 0.8% (range, 0.4%–1.9%) for pipetting 100 μL, and 0.2% (range, 0.1%–0.5%) for pipetting 1 mL. Overall, the mean inter-individual imprecision was 8.1% for pipetting 10 μL, 1.1% for pipetting 100 μL and 0.4% for pipetting 1 mL. A significantly inverse correlation was found between intra-individual pipetting imprecision and the amount of water dispensed (r = –0.80; p<0.001). No significant correlation was observed between individual pipetting performance and sex, age, qualification, and years of experience in the laboratory.Conclusions: The results of this study show that manual pipetting is plagued by a considerable intra- and inter-individual imprecision, which is inversely correlated with the amount of fluid dispensed.

Background: This retrospective study was planned to establish potential associations between circulating values of cardiac troponins and those of conventional blood lipids. Methods: The study population consisted of patients attending an inpatient clinic of the University Hospital of Verona during the year 2015 as part of routine cardiovascular risk assessment. No exclusion criteria were applied. Serum lipids including total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and triglycerides (TG) were measured using reference enzymatic techniques, whereas troponin T (TnT) was measured using a high-sensitivity (HS) immunoassay. A second analysis was also performed in the General Hospital of Verona, extracting data from the local laboratory database of all patients in whom troponin I (TnI) and blood lipids were simultaneously measured during the same year. Results: In univariate analysis, HS-TnT was found to be associated with age, sex, TC, LDL-C, HDL-C, but not with TG. In multivariate linear regression analysis, age (positive correlation; P50 ng/L was higher in subjects with HDL-C 50 ng/L was also higher in elderly subjects than in younger ones (OR, 2.10; 95% CI, 1.15–3.84). The combination of age and HDL-C explained 35% of overall variability of TnT concentration. In the second analysis, HDL-C was also found to be an independent and negative predictor of TnI in multivariate linear regression analysis (P=0.010). The combination of age and HDL-C explained approximately 28% of the overall variability of TnI concentration. Conclusions: Our study suggests that HDL-C values inversely predict cardiac troponins concentration irrespective of age, sex and other blood lipids.