Blood Homocysteine Levels Mediate the Association Between Blood Lead Levels and Cardiovascular Mortality.

Lead is a heavy, toxic metal and its exposure to humans can lead to increased risk of cardiovascular disease development and mortality. Lead exposure has been shown to induce hyperhomocysteinemia (HHCy) which may be a major pathogenic risk for the risk of CVDs. The aim of this study was to investigate whether homocysteine (Hcy) mediates the effect of lead on cardiovascular mortality. A total of 17,915 adults aged ≥ 20 who participated in the National Health and Nutrition Examination Survey (1999 to 2006). Information on mortality was ascertained via probabilistic matching to the death certificates from the National Death Index recorded up to December 31, 2015. Cox proportional hazards regression was performed to assess the association between blood lead levels and mortality. Mediation via Hcy was examined using a logit model. During a mean follow-up of 11.6 years, the incidences of CVD mortality were 0.73, 2.18, 3.03 and 4.94 per 1000 person-years across quarterlies of blood lead levels from low to high. Following multivariable adjustment, blood lead levels were strongly associated with CVD mortality in all mortality models (p-trend < 0.001). This association remained statistically significant after further adjusting for quartiles of homocysteine (model 3; HR 1.38 (95% CI 1.01-1.89) p-trend < 0.001). Furthermore, blood lead levels increased the odds of CVD mortality via homocysteine (indirect effect) (OR 1.42 (95% CI 1.30-1.55)), demonstrating the mediatory effect of homocysteine. This the first study that demonstrates that increased homocysteine mediates nearly half of CVD mortality related to blood lead levels.

Effectiveness of Convalescent Plasma Therapy in COVID-19 Patients with Hematological Malignancies: A Systematic Review.

Background: Immunocompromised patients, including those with hematological malignancies, are at a high risk of developing severe coronavirus disease 2019 (COVID-19) complications. Currently, there is a limited number of systematic reviews into the efficacy of convalescent plasma therapy (CPT) use in the treatment of COVID-19 patients with hematological malignancies. Therefore, the aim of this review was to systematically appraise the current evidence for the clinical benefits of this therapy in COVID-19 patients with hematological malignancies. Methods: A comprehensive search was conducted up to April 2022, using four databases: PubMed, Web of Science, Science Direct, and Scopus. Two reviewers independently assessed the quality of the included studies. Data collection analysis was performed using Microsoft Excel 365 and GraphPad Prism software. Results: 18 studies met the inclusion criteria; these records included 258 COVID-19 patients who had hematological malignancies and were treated with CPT. The main findings from the reviewed data suggest that CPT may be associated with improved clinical outcomes, including (a) higher survival rate, (b) improved SARS-CoV-2 clearance and presence of detectable anti-SARS-CoV-2 antibodies post CP transfusion, and (c) improved hospital discharge time and recovery after 1 month of CPT. Furthermore, treatment with convalescent plasma was not associated with the development of adverse events. Conclusions: CPT appears to be an effective supportive therapeutic option for hematological malignancy patients infected with COVID-19. To our knowledge, this is one of the first systematic reviews of the clinical benefits of CPT in COVID-19 patients with hematological malignancies.

ABO blood group association and COVID-19. COVID-19 susceptibility and severity: a review

Abstract Introduction The SARS-CoV-2 pandemic has been affecting the health and economic, as well as social, life of the entire globe since the end of 2019. The virus causes COVID-19, with a wide range of symptoms among the infected individuals, from asymptomatic infection to mortality. This, along with a high infection rate, prompted efforts to investigate the potential mechanisms of the different clinical manifestations caused by SARS-CoV-2 among the infected populations. Hypothesis One of the possible mechanisms that has been reported is the ABO blood system polymorphism. Indeed, one of the major proposed mechanisms is the presence of naturally occurring anti-A antibodies in individuals of groups O and B, which could be partially protective against SARS-CoV-2 virions. Objective and Method This article aimed to review the published data on the potential effect of the ABO blood group system on the susceptibility to COVID-19 and the disease progression and outcomes. Results The reviewed data suggest that individuals of blood group A are at a higher risk of infection with SARS-CoV-2 and may develop severe COVID-19 outcomes, whereas blood group O is considered protective against the infection, to some extent. However, some of the available studies seem to have been influenced by unaccounted confounders and biases. Conclusion Therefore, further appropriately controlled studies are warranted to fully investigate the possible association between the ABO blood groups and COVID-19 susceptibility and severity.

Anthocyanin Supplementation Alleviates Antithrombotic Risk by Inhibiting Platelet Activity in Humans.

BACKGROUND: Platelet hyperactivity has a crucial role in initiating vascular thrombosis and subsequent cardiovascular disease (CVD). OBJECTIVE: This study aimed to assess the effect of anthocyanins (AC) on platelet aggregation and activation and lipid profile. STUDY DESIGN: A total of 26 healthy participants consumed 320 mg of AC/day in the form of Medox® capsules for 28 days. SETTING: This study was conducted in the laboratories of the School of Medical Sciences, Griffith University, Gold Coast, Australia. PARTICIPANTS: A total of 26 randomly recruited healthy 25- to 75-year-old participants completed this study. PRIMARY OUTCOME MEASURES: Fasting blood samples were collected pre- and post-the intervention period to perform platelet activation studies by measuring platelet surface marker expression of CD41a and P-selectin, and platelet-monocyte aggregates in adenosine diphosphate (ADP) stimulated platelets. Platelet aggregation studies were performed by stimulating platelets with various agonists such as ADP, collagen and arachidonic acid. Full blood examination, coagulation and biochemistry profile analyses were also performed pre- and post-intervention. Flow cytometric analysis showed a significant effect of AC on the expression of P-selectin as measured by the platelet surface expression of CD62p. RESULTS: There was a significant reduction of ADP-stimulated platelet aggregation. Hematologic analysis showed a significant reduction of mean platelet volume, mean cell hemoglobin, and mean cell hemoglobin concentration. Coagulation analysis demonstrated significant attenuation of fibrinogen level in the blood. CONCLUSION: This study showed inhibition of platelet activity, platelet aggregation and mean platelet volume (MPV). These results suggest that AC has a positive impact on attenuating platelet activity, which might minimize thrombotic risk.

ABO blood group association and COVID-19. COVID-19 susceptibility and severity: a review.

INTRODUCTION: The SARS-CoV-2 pandemic has been affecting the health and economic, as well as social, life of the entire globe since the end of 2019. The virus causes COVID-19, with a wide range of symptoms among the infected individuals, from asymptomatic infection to mortality. This, along with a high infection rate, prompted efforts to investigate the potential mechanisms of the different clinical manifestations caused by SARS-CoV-2 among the infected populations. HYPOTHESIS: One of the possible mechanisms that has been reported is the ABO blood system polymorphism. Indeed, one of the major proposed mechanisms is the presence of naturally occurring anti-A antibodies in individuals of groups O and B, which could be partially protective against SARS-CoV-2 virions. OBJECTIVE AND METHOD: This article aimed to review the published data on the potential effect of the ABO blood group system on the susceptibility to COVID-19 and the disease progression and outcomes. RESULTS: The reviewed data suggest that individuals of blood group A are at a higher risk of infection with SARS-CoV-2 and may develop severe COVID-19 outcomes, whereas blood group O is considered protective against the infection, to some extent. However, some of the available studies seem to have been influenced by unaccounted confounders and biases. CONCLUSION: Therefore, further appropriately controlled studies are warranted to fully investigate the possible association between the ABO blood groups and COVID-19 susceptibility and severity.

Thrombotic and Hypercoagulability Complications of COVID-19: An Update.

The current COVID-19 pandemic emerged in December 2019, in China, affecting millions of people worldwide. COVID-19 is mainly a disease of the respiratory system, yet systematic complications have also been reported among SARS-CoV-2 infected patients. Thrombotic complications are one of the severe clinical outcomes of COVID-19, especially among critically ill patients, and are associated with poor prognosis. To date, many studies have concluded that COVID-19 increases the incidence of thrombotic events and coagulopathies; however, the exact mechanism behind such a disease outcome is not well known. Various pathophysiological mechanisms for thrombotic events in COVID-19 have been proposed, these include virus-induced endothelial cell damage, inflammation, and excess production of pro-inflammatory cytokines. As a result, most critically diseased COVID-19 patients are managed with prophylactic anticoagulant, yet some still develop thrombotic episodes. Therefore, better understanding of the mechanisms behind the thrombotic complications is needed to develop treatments that specifically target such pathways, which may aid in better disease management and improve the prognosis.

Effect of Silymarin Treatment on Circulating Bilirubin and Cardiovascular Disease Risk Factors in Healthy Men: A Single-Blind, Randomized Crossover Trial.

This clinical trial (ACTRN12619001296123) investigated the impact of silymarin (Legalon®) on circulating bilirubin concentration, lipid status, systemic inflammation, and antioxidant status. The study design was a randomized, placebo-controlled, single-blind crossover trial of healthy men (18-65 years), conducted at Griffith University, Gold Coast, Australia. Participants were recruited from Griffith University and were randomized to silymarin (140 mg silymarin capsules thrice daily) or placebo (3 capsules containing mannitol taken daily) for 14 days followed by a ≥4-week washout and crossover to the other arm. The main outcomes were whether silymarin treatment would increase serum bilirubin concentration by >0.29 mg/dL, change serum lipid status (cholesterol and triglycerides), inflammation (c-reactive protein), and antioxidant capacity (ferric reducing ability of plasma) compared with baseline. Silymarin consumption (n = 17) did not affect serum concentrations of unconjugated bilirubin (0.73 versus 0.67 mg/dL, P = .79), cholesterol (185 versus 189 mg/dL, P = .19), triglycerides (94.2 versus 92.3 mg/dL, P = .79), c-reactive protein (0.17 versus 0.09 mg/dL, P = .23), or antioxidant status (6.61 versus 6.67 mg Fe2+ /dL, P = .40). These findings challenge previous reports and manufacturer claims of hyperbilirubinemia following silymarin treatment and are critical to guiding researchers toward an effective means to mildly elevate bilirubin, which evidence suggests could protect from cardiovascular disease.

Assessment of in vitro Effects of Anthocyanins on Platelet Function.

BACKGROUND: Increased platelet activity plays a significant role in the development of arterial thrombosis and cardiovascular disease (CVD). Natural antioxidants including anthocyanin (AC) have gained considerable interest due to their hypothesized antithrombotic potential. PRIMARY STUDY OBJECTIVE: Our study aimed to examine the in vitro effect of AC compounds on platelet activation and aggregation. METHODS: Fasting blood samples were collected from healthy volunteers (n = 13). A full blood examination was done to exclude any abnormal specimen. Flow cytometer assessed platelet activity by recording platelet surface markers expression of P-selectin (CD62P) and PAC-1. Platelet aggregation studies were performed by stimulating platelets using three different agonists adenosine diphosphate (ADP), collagen and arachidonic acid (AA). SETTING: The study was done in the school of Medical Sciences, Griffith University. PARTICIPANTS: Thirteen healthy adult participants were involved for blood collection. INTERVENTION: AC was prepared using hemicellulose capsules sourced from Bilberries and Black Currants. RESULTS: Anthocyanin (50 mg/L) significantly inhibited AA-induced platelet aggregation. Expression of P-selectin was significantly suppressed by 50 mg/L AC as measured by flow cytometer. CONCLUSIONS: AC attenuates platelet function by suppressing P-selectin expression and influencing Thromboxane A2 pathway (AA stimulation). These results provide further evidence for the effect of AC and the possible mechanism by which AC reduces platelet aggregation and activation. This study supports future human intervention trials to show that AC may act as a complement to other antiplatelet agents in reducing the risk of thrombosis.

The impact of bilirubin ditaurate on platelet quality during storage.

Bilirubin ditaurate (BRT), a conjugated bilirubin analogue, has demonstrated anti-platelet characteristics following acute ex vivo exposure. Scavenging of mitochondrial superoxide and attenuation of granule exocytosis suggested a potential benefit for including BRT for storage. With no reports of cytotoxicity following acute exposure, the impact of 35µM BRT on platelet function was investigated, in clinically suppled units, for up to seven days. Exposure to 35µM BRT significantly reduced mitochondrial membrane potential and increased glucose consumption until exhaustion after 72 hours. Platelet aggregation and activation was significantly impaired by BRT. Mitochondrial superoxide production and phosphatidylserine expression were significantly elevated following glucose exhaustion, with decreased viability observed from day five onwards. Lactate accumulation and loss of bicarbonate, support a metabolic disturbance, leading to a decline of quality following BRT inclusion. Although acute ex vivo BRT exposure reported potentially beneficial effects, translation from acute to chronic exposure failed to combat declining platelet function during storage. BRT exposure resulted in perturbations of platelet quality, with the utility of BRT during storage therefore limited. However, these are the first data of prolonged platelet exposure to analogues of conjugated bilirubin and may improve our understanding of platelet function in the context of conjugated hyperbilirubinemia.