Catastrophic Thrombosis: A Narrative Review.

Catastrophic thrombosis is a severe condition characterized by a hypercoagulable tendency, leading to multiple thromboembolic events in different blood vessels, usually within a short timeframe. Several conditions have been associated with the development of catastrophic thrombosis, including the catastrophic antiphospholipid syndrome, thrombotic anti-platelet factor 4 immune disorders, thrombotic microangiopathies, cancers, the hyper-eosinophilic syndrome, pregnancy, infections, trauma, and drugs. Thrombotic storm represents a medical emergency whose management represents a serious challenge for physicians. Besides the prompt start of anticoagulation, a patient's prognosis depends on early recognition and possible treatment of the underlying condition. In this narrative review, we summarize the main characteristics of catastrophic thrombosis, analyzing the various conditions triggering such life-threatening complication. Finally, an algorithm with the diagnostic workup and the initial management of patients with catastrophic thrombosis is presented.

Factor IX stimulants in preclinical and early phase trials for hemophilia B treatment.

INTRODUCTION: Hemophilia B is a X-linked rare inherited bleeding disorder characterized by coagulation factor IX (FIX) deficiency. Therapy for hemophilia B is aimed at replacing the FIX deficiency by means of several plasma-derived or recombinant FIX products. The recent availability of recombinant FIX concentrates with a prolonged FIX half-life represented a great technological advance, permitting more spaced drug infusions and reducing treatment burden among hemophilia B patients. AREAS COVERED: This review summarizes the main preclinical and phase 1/2 studies investigating the innovative hemostatic products for hemophilia B replacement therapy. EXPERT OPINION: The significant recent technological advantages in the treatment of hemophilia B has led to the development of innovative FIX products aimed at further extending FIX half-life and using increasingly effective and convenient modes of administration. These novel hemostatic agents, currently in the preclinical or early clinical phase of development, carry the potential of improving patients' health status and quality of life. Continuous research is anyway needed to offer such patients a concrete chance of conducting a normal existence, like to non-affected age-matched individuals.

Monoclonal Antibody Therapies Against SARS-CoV-2: Promises and Realities.

Monoclonal antibodies targeting the Spike protein of SARS-CoV-2 have been widely deployed in the ongoing COVID-19 pandemic. I review here the impact of those therapeutics in the early pandemic, ranging from structural classification to outcomes in clinical trials to in vitro and in vivo evidence of basal and treatment-emergent immune escape. Unfortunately, the Omicron variant of concern has completely reset all achievements so far in mAb therapy for COVID-19. Despite the intrinsic limitations of this strategy, future developments such as respiratory delivery of further engineered mAb cocktails could lead to improved outcomes.

Considerations for the development of monoclonal antibodies to address new viral variants in COVID-19.

INTRODUCTION: Monoclonal antibody (mAb) therapies proved safe and effective in preventing progression of COVID-19 to hospitalization, but most were eventually defeated by continued viral evolution. mAb combinations and those mAbs that were deliberatively selected to target conserved regions of the SARS-CoV-2 spike protein proved more resilient to viral escape variants as evident by longer clinical useful lives. AREAS COVERED: We searched PubMed for literature covering the need, development, and use of mAb therapies for COVID-19. As much of humanity now has immunity to SARS-CoV-2, the population at most risk is that of immunocompromised individuals. Hence, there continues to be a need for mAb therapies for immunocompromised patients. However, mAb use in this population carries the risk for selecting mAb-resistant variants, which could pose a public health concern if they disseminate to the general population. EXPERT OPINION: Going forward, structural knowledge of the interactions of Spike with its cellular receptor has identified several regions that may be good targets for future mAb therapeutics. A focus on designing variant-resistant mAbs together with cocktails that target several epitopes and the use of other variant mitigating strategies such as the concomitant use of small molecule antivirals and polyclonal preparations could extend the clinical usefulness of future preparations.

Avian Influenza Virus A(H5Nx) and Prepandemic Candidate Vaccines: State of the Art.

Avian influenza virus has been long considered the main threat for a future pandemic. Among the possible avian influenza virus subtypes, A(H5N1) clade 2.3.4.4b is becoming enzootic in mammals, representing an alarming step towards a pandemic. In particular, genotype B3.13 has recently caused an outbreak in US dairy cattle. Since pandemic preparedness is largely based on the availability of prepandemic candidate vaccine viruses, in this review we will summarize the current status of the enzootics, and challenges for H5 vaccine manufacturing and delivery.

Single monoclonal antibodies should not be used for COVID-19 therapy: a call for antiviral stewardship.

The COVID-19 pandemic saw the largest deployment of monoclonal antibodies (mAbs) for an infectious disease in history. mAbs to SARS-CoV-2 spike protein proved safe and were initially effective for COVID-19 therapy, but each was defeated by continued SARS-CoV-2 evolution, leading to their withdrawal. This was a setback for people with impaired immunity who cannot mount an effective antibody response to SARS-CoV-2 and often cannot clear the virus. New mAbs have now been developed for pre-exposure prophylaxis (PreEP) in immunosuppressed people. Here we argue that while mAb use for PreEP is justified, single mAbs should not be used for COVID-19 therapy. In contrast to PreEP where the viral inoculum is small, immunosuppressed people with COVID-19 have large viral burden that can harbor mAb-escape variants that single-agent mAb treatments can rapidly select for resistance. Selection of mAb-escape variants has potential risks for patients, society and the feasibility of mAb therapy itself.

Exploring Study Design Foibles in Randomized Controlled Trials on Convalescent Plasma in Hospitalized COVID-19 Patients.

Background: Sample size estimation is an essential step in the design of randomized controlled trials (RCTs) evaluating a treatment effect. Sample size is a critical variable in determining statistical significance and, thus, it significantly influences RCTs' success or failure. During the COVID-19 pandemic, many RCTs tested the efficacy of COVID-19 convalescent plasma (CCP) in hospitalized patients but reported different efficacies, which could be attributed to, in addition to timing and dose, inadequate sample size estimates. Methods: To assess the sample size estimation in RCTs evaluating the effect of treatment with CCP in hospitalized COVID-19 patients, we searched the medical literature between January 2020 and March 2024 through PubMed and other electronic databases, extracting information on expected size effect, statistical power, significance level, and measured efficacy. Results: A total of 32 RCTs were identified. While power and significance level were highly consistent, heterogeneity in the expected size effect was relevant. Approximately one third of the RCTs did not reach the planned sample size for various reasons, with the most important one being slow patient recruitment during the pandemic's peaks. RCTs with a primary outcome in favor of CCP treatment had a significant lower median absolute difference in the expected size effect than unfavorable RCTs (20.0% versus 33.9%, P = 0.04). Conclusions: The analyses of sample sizes in RCTs of CCP treatment in hospitalized COVID-19 patients reveal that many underestimated the number of participants needed because of excessively high expectations on efficacy, and thus, these studies had low statistical power. This, in combination with a lower-than-planned recruitment of cases and controls, could have further negatively influenced the primary outcomes of the RCTs.

Convalescent plasma and predictors of mortality among hospitalized patients with COVID-19: a systematic review and meta-analysis.

BACKGROUND: Plasma collected from recovered patients with COVID-19 (COVID-19 convalescent plasma [CCP]) was the first antibody-based therapy employed to fight the COVID-19 pandemic. While the therapeutic effect of early administration of CCP in COVID-19 outpatients has been recognized, conflicting data exist regarding the efficacy of CCP administration in hospitalized patients. OBJECTIVES: To examine the effect of CCP compared to placebo or standard treatment, and to evaluate whether time from onset of symptoms to treatment initiation influenced the effect. DATA SOURCES: Electronic databases were searched for studies published from January 2020 to January 2024. STUDY ELIGIBILITY CRITERIA: Randomized clinical trials (RCTs) investigating the effect of CCP on COVID-19 mortality in hospitalized patients with COVID-19. PARTICIPANTS: Hospitalized patients with COVID-19. INTERVENTIONS: CCP versus no CCP. ASSESSMENT OF RISK OF BIAS: Cochrane risk of bias tool for RCTs. METHODS OF DATA SYNTHESIS: The random-effects model was used to calculate the pooled risk ratio (RR) with 95% CI for the pooled effect estimates of CCP treatment. The Grading of Recommendations Assessment, Development and Evaluation was used to evaluate the certainty of evidence. RESULTS: Twenty-seven RCTs were included, representing 18,877 hospitalized patients with COVID-19. When transfused within 7 days from symptom onset, CCP significantly reduced the risk of death compared to standard therapy or placebo (RR, 0.76; 95% CI, 0.61-0.95), while later CCP administration was not associated with a mortality benefit (RR, 0.98; 95% CI, 0.90-1.06). The certainty of the evidence was graded as moderate. Meta-regression analysis demonstrated increasing mortality effects for longer interval to transfusion or worse initial clinical severity. CONCLUSIONS: In-hospital transfusion of CCP within 7 days from symptom onset conferred a mortality benefit.

Monoclonal Antibodies and Hyperimmune Immunoglobulins in the Next Pandemic.

Pandemics are highly unpredictable events that are generally caused by novel viruses. There is a high likelihood that such novel pathogens belong to entirely novel viral families for which no targeted small-molecule antivirals exist. In addition, small-molecule antivirals often have pharmacokinetic properties that make them contraindicated for the frail patients who are often the most susceptible to a novel virus. Passive immunotherapies-available from the first convalescent patients-can then play a key role in controlling pandemics. Convalescent plasma is immediately available, but if manufacturers have fast platforms to generate marketable drugs, other forms of passive antibody treatment can be produced. In this chapter, we will review the technological platforms for generating monoclonal antibodies and hyperimmune immunoglobulins, the current experience on their use for treatment of COVID-19, and the pipeline for pandemic candidates.

MPXV DNA kinetics in bloodstream and other body fluids samples.

Since spring 2022, the global epidemiology of the monkeypox virus (MPXV) has changed. The unprecedented increase of human clade II MPXV cases worldwide heightened concerns about this emerging zoonotic disease. We analysed the positivity rates, viral loads, infectiousness, and persistence of MPXV DNA for up to 4 months in several biological samples from 89 MPXV-confirmed cases. Our data showed that viral loads and positivity rates were higher during the first two weeks of symptoms for all sample types. Amongst no-skin-samples, respiratory specimens showed higher MPXV DNA levels and median time until viral clearance, suggesting their usefulness in supporting MPXV diagnosis, investigating asymptomatic patients, and monitoring viral shedding. Infectious virus was cultured from respiratory samples, semen, and stools, with high viral loads and collected within the first 10 days. Notably, only one saliva and one semen were found positive for viral DNA after 71 and 31 days from symptoms, respectively. The focus on bloodstream samples showed the best testing sensitivity in plasma, reporting the overall highest MPXV DNA detection rate and viral loads during the 3-week follow-up as compared to serum and whole-blood. The data here presented can be useful for MPXV diagnostics and a better understanding of the potential alternative routes of its onward transmission.

Torquetenovirus Viremia Quantification Using Real-Time PCR Developed on a Fully Automated, Random-Access Platform.

Quantification of Torquetenovirus (TTV) viremia is becoming important for evaluating the status of the immune system in solid organ transplant recipients, monitoring the appearance of post-transplant complications, and controlling the efficacy of maintenance immunosuppressive therapy. Thus, diagnostic approaches able to scale up TTV quantification are needed. Here, we report on the development and validation of a real-time PCR assay for TTV quantification on the Hologic Panther Fusion® System by utilizing its open-access channel. The manual real-time PCR previously developed in our laboratories was optimized to detect TTV DNA on the Hologic Panther Fusion® System. The assay was validated using clinical samples. The automated TTV assay has a limit of detection of 1.6 log copies per ml of serum. Using 112 samples previously tested via manual real-time PCR, the concordance in TTV detection was 93% between the assays. When the TTV levels were compared, the overall agreement between the methods, as assessed using Passing-Bablok linear regression and Bland-Altman analyses, was excellent. In summary, we validated a highly sensitive and accurate method for the diagnostic use of TTV quantification on a fully automated Hologic Panther Fusion® System. This will greatly improve the turnaround time for TTV testing and better support the laboratory diagnosis of this new viral biomarker.

The Emerging Tool of the Human Anellovirome.

The blood virome is dominated by the Anelloviridae family, which emerges early in life; the anellome, which represents the variety of anelloviruses within an individual, stabilizes by adulthood [...].

Molnupiravir increases SARS-CoV-2 genome diversity and complexity: A case-control cohort study.

Molnupiravir, an oral direct-acting antiviral effective in vitro against SARS-CoV-2, has been largely employed during the COVID-19 pandemic, since December 2021. After marketing and widespread usage, a progressive increase in SARS-CoV-2 lineages characterized by a higher transition/transversion ratio, a characteristic signature of molnupiravir action, appeared in the Global Initiative on Sharing All Influenza Data (GISAID) and International Nucleotide Sequence Database Collaboration (INSDC) databases. Here, we assessed the drug effects by SARS-CoV-2 whole-genome sequencing on 38 molnupiravir-treated persistently positive COVID-19 outpatients tested before and after treatment. Seventeen tixagevimab/cilgavimab-treated outpatients served as controls. Mutational analyses confirmed that SARS-CoV-2 exhibits an increased transition/transversion ratio seven days after initiation of molnupiravir. Moreover we observed an increased G->A ratio compared to controls, which was not related to apolipoprotein B mRNAediting enzyme, catalytic polypeptide-like (APOBEC) activity. In addition, we demonstrated for the first time an increased diversity and complexity of the viral quasispecies.

Response to the Comment: "Advocating prudent D-dimer testing: constructive perspectives and comments on "How we manage a high D-dimer".

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COVID-19 therapeutics.

SUMMARYSince the emergence of COVID-19 in 2020, an unprecedented range of therapeutic options has been studied and deployed. Healthcare providers have multiple treatment approaches to choose from, but efficacy of those approaches often remains controversial or compromised by viral evolution. Uncertainties still persist regarding the best therapies for high-risk patients, and the drug pipeline is suffering fatigue and shortage of funding. In this article, we review the antiviral activity, mechanism of action, pharmacokinetics, and safety of COVID-19 antiviral therapies. Additionally, we summarize the evidence from randomized controlled trials on efficacy and safety of the various COVID-19 antivirals and discuss unmet needs which should be addressed.

Inhibitor eradication and treatment for acquired hemophilia A.

INTRODUCTION: Acquired hemophilia A (AHA) is a rare hemorrhagic autoimmune disorder characterized by autoantibodies against coagulation factor VIII (FVIII). In approximately half of the cases AHA does not recognize any cause (idiopathic form), while in the other cases it may be triggered by autoimmune disorders, cancers, drugs, infections, or pregnancy. Besides treating the underlying disorder, specific AHA treatment includes management of bleeding, if necessary, and inhibitor eradication. AREAS COVERED: This narrative review summarizes the main epidemiological, clinical, laboratory, and therapeutic characteristics of AHA. In particular, it is focused on the current therapeutic options for the inhibitor eradication, also showing the latest findings on the innovative therapies. A literature search strategy was performed, without temporal limits, through Medline and PubMed electronic databases. EXPERT OPINION: Various first-line and second-line immunosuppressive agents are currently available for the management of AHA. Among the latter, the anti-CD20 monoclonal antibody rituximab has been the object of intense research during the last years from investigators as innovative promising eradicating therapy for AHA. Preliminary data from the studies support the use of this drug as a first-line option for newly diagnosed AHA cases.

Online dashboards for SARS-CoV-2 wastewater-based epidemiology.

Aim: Wastewater-based epidemiology (WBE) is increasingly used to monitor pandemics. In this manuscript, we review methods and limitations of WBE, as well as their online dashboards. Materials & methods: Online dashboards were retrieved using PubMed and search engines, and annotated for timeliness, availability of English version, details on SARS-CoV-2 sublineages, normalization by population and PPMoV load, availability of case/hospitalization count charts and of raw data for export. Results: We retrieved 51 web portals, half of them from Europe. Africa is represented from South Africa only, and only seven portals are available from Asia. Conclusion: WBS provides near-real-time cost-effective monitoring of analytes across space and time in populations. However, tremendous heterogeneity still persists in the SARS-CoV-2 WBE literature.

Monitoring the amount of a virus in the sewage system provides a way to work out the circulation of the virus among a population at a given time. Standard procedures are needed to produce data that can be compared across countries. Timely sharing of wastewater surveillance data across publicly accessible web portals is important to inform researchers and plan public health policies. This study shows that we are still far away from standardization and timely and transparent reporting.