Role of the Hemostasis and Thrombosis Unit in the Management of Patients with Acquired Hemophilia A.

Objective: Acquired hemophilia A (AHA) is a rare autoimmune disease characterized by the presence of autoantibodies against coagulation factor VIII, leading to spontaneous hemorrhage in patients without a prior family or personal history of bleeding. This study describes the demographics, diagnosis, underlying disorders, bleeding characteristics, treatment, and outcomes of 41 AHA patients together with specific case reports.

Materials And Methods: Diagnosis and treatment of these patients occurred between 2005 and 2023.

Over-anticoagulation by vitamin K antagonists and gender differences.

Background: Several studies have shown that in patients treated with vitamin K antagonists (VKAs) time spent in therapeutic range (TTR) is lower in females than in males. This retrospective study has evaluated a possible association among over-anticoagulation and gender, type and indications to VKAs, TTR and bleeding. Moreover, the decrease of the INR level, after VKAs withdrawal, was considered.

Clinical history and gastrointestinal bleeding in patients taking oral anticoagulants.

Background: Common risk factors for gastrointestinal bleeding (GIB) are advanced age and the use of antiplatelet or anticoagulants drugs for the prevention of cardiovascular diseases.

Methods: In this prospective real-world observational study, oral anticoagulated patients were recruited and followed between June 2013 and December 2019. The primary end-point was to evaluate a possible relationship between bleeding events and patients' clinical history of gastrointestinal disease prior to the start of the therapy.

Clot characterization by multidisciplinary approach: biochemical and imaging parameters in a hypocoagulative setting. A pilot study.

Background: Clot characterization is, to the present days, a multimodal approach: scanning the clot by electron microscopy (SEM) is helpful for the visualization of fibrin structure along with laboratory parameters such as the clot waveform analysis (CWA) and thrombin generation in different settings of clot abnormalities. This study aimed to assess whether the coagulative parameters were consistent with the clot images texture acquired by SEM, and therefore to propose a more generalist and integrative approach to clots classification.

Design And Methods: In this pilot study, the examined population consists of eight healthy subjects, seven patients affected by Acquired Hemophilia A (AHA) and seven patients treated with Vitamin K Antagonists (VKAs), similar for age and gender.

Point-of-care testing INR: an overview.

Oral anticoagulant therapies with the anti-vitamin K drugs (AVK), warfarin, acenocoumarol and phenprocoumon, are employed in primary and secondary anti-thrombotic prophylaxis in patients with venous thromboembolism, atrial fibrillation and cardiac mechanical valves. However, a monitoring test such as the International Normalized Ratio (INR) is required. The periodic monitoring of this therapy entails discomfort for the patients.

Quantifying the impact of transporters on cellular drug permeability.

The conventional model of drug permeability has recently been challenged. An alternative model proposes that transporter-mediated flux is the sole mechanism of cellular drug permeation, instead of existing in parallel with passive transmembrane diffusion. We examined a central assumption of this alternative hypothesis; namely, that transporters can give rise to experimental observations that would typically be explained with passive transmembrane diffusion.

The criteria of the Italian Federation of Thrombosis Centres on DOACs: a "real world" application in nonvalvular atrial fibrillation patients already on vitamin K antagonist.

The aim of this study was to evaluate the number of patients with nonvalvular atrial fibrillation (NVAF), anticoagulated with vitamin K antagonists (VKA), and monitored in our Thrombosis Centre, who could replace VKA with direct oral anticoagulants (DOACs) based on the Italian Federation of Thrombosis Centres (FCSA) consensus criteria. A total of 525 NVAF patients treated with VKA were studied. Therapeutic range (TTR) assessment and a capillary test for serum creatinine measure were carried out.

Bleeding diathesis and gastro-duodenal ulcers in inherited cytosolic phospholipase-A2 alpha deficiency.

Arachidonic acid (AA), when cleaved from phospholipids by cytosolic phospholipase A2 alpha (cPLA2a), generates eicosanoids, with pro-hemostatic, pro-inflammatory, vasoactive and gastro-protective functions. We describe a patient (27-year-old man) and his twin-sister with early-onset bleeding diathesis and recurrent gastro-intestinal (GI) ulcers. Platelet aggregation/δ-granules secretion by collagen was impaired, but normal by AA; serum levels of thromboxane (Tx) B2 and 12-hydroxyeicosatetraenoic acid, and urinary levels of 11-dehydro-TxB2 were extremely low.

Telemedicine can improve the quality of oral anticoagulation using portable devices and self-testing at home.

Point-of-care testing (POCT) devices can be used to monitor anticoagulant therapy. We compared patients being monitored at home by self-testing using a POCT device and telemedicine support with a previous period of conventional monitoring at a Thrombosis Centre. A total of 114 anticoagulated patients participated.

Identification of a novel and recurrent mutation in the SERPING1 gene in patients with hereditary angioedema.

Hereditary angioedema (HAE) due to C1 inhibitor (C1-INH) deficiency is an autosomal dominant disorder caused by mutations in SERPING1 gene. More than 200 different mutations are known, with high genetic heterogeneity and high frequency of private familial mutations. We analyzed for genetic mutations the C1-INH locus in 11 Sardinian families, revealing in seven subjects from four unrelated families the novel nonsense mutation S318X.

Towards a better prediction of peak concentration, volume of distribution and half-life after oral drug administration in man, using allometry.

Background: It is imperative that new drugs demonstrate adequate pharmacokinetic properties, allowing an optimal safety margin and convenient dosing regimens in clinical practice, which then lead to better patient compliance. Such pharmacokinetic properties include suitable peak (maximum) plasma drug concentration (C(max)), area under the plasma concentration-time curve (AUC) and a suitable half-life (t(½)). The C(max) and t(½) following oral drug administration are functions of the oral clearance (CL/F) and apparent volume of distribution during the terminal phase by the oral route (V(z)/F), each of which may be predicted and combined to estimate C(max) and t(½).

Cardio-vascular safety beyond hERG: in silico modelling of a guinea pig right atrium assay.

As chemists can easily produce large numbers of new potential drug candidates, there is growing demand for high capacity models that can help in driving the chemistry towards efficacious and safe candidates before progressing towards more complex models. Traditionally, the cardiovascular (CV) safety domain plays an important role in this process, as many preclinical CV biomarkers seem to have high prognostic value for the clinical outcome. Throughout the industry, traditional ion channel binding data are generated to drive the early selection process.

Point-of-care (POCT) prothrombin time monitors: is a periodical control of their performance useful?

Introduction: Point-of-care testing (POCT) prothrombin time monitors are now widely used to monitor oral anticoagulant treatment. Although portable coagulometers are extremely easy to use, checking the quality of their performance presents some difficulties.

Materials And Methods: The aims of this study were to investigate on a quarterly basis the performance of 95 Coagucheck S assigned to 99 anticoagulated patients at home.

Incidence of neutropenia and infections during combination treatment of chronic hepatitis C with pegylated interferon alfa-2a or alfa-2b plus ribavirin.

Background: Combination therapy with pegylated interferon (peginterferon) plus ribavirin is associated with several side effects, including neutropenia and infection.

Aims: To evaluate the incidence of neutropenia and infection between all consecutive patients with hepatitis C who were treated in two centers with peginterferon-alfa-2a and peginterferon-alfa-2b, in combination with ribavirin and actively monitored for occurrence of any infection.

Methods: A total of 319 consecutive patients with chronic hepatitis C received once-weekly peginterferon alfa-2b at a weight-adjusted dose (n=162) or peginterferon alfa-2a at a flat dose (n=157), plus ribavirin.

Predicting oral clearance in humans: how close can we get with allometry?

Background: Oral clearance (CL/F) is an important pharmacokinetic parameter and plays an important role in the selection of a safe and tolerable dose for first-in-human studies. Throughout the pharmaceutical industry, many drugs are administered via the oral route; however, there are only a handful of published scaling studies for the prediction of oral pharmacokinetic parameters.

Methods: We evaluated the predictive performances of four different allometric approaches -- simple allometry (SA), the rule of exponents, the unbound CL/F approach, and the unbound fraction corrected intercept method (FCIM) -- for the prediction of human CL/F and the oral area under the plasma concentration-time curve (AUC).

Prediction of human pharmacokinetics using physiologically based modeling: a retrospective analysis of 26 clinically tested drugs.

The aim of this study was to evaluate different physiologically based modeling strategies for the prediction of human pharmacokinetics. Plasma profiles after intravenous and oral dosing were simulated for 26 clinically tested drugs. Two mechanism-based predictions of human tissue-to-plasma partitioning (P(tp)) from physicochemical input (method Vd1) were evaluated for their ability to describe human volume of distribution at steady state (V(ss)).

The prediction of drug metabolism, tissue distribution, and bioavailability of 50 structurally diverse compounds in rat using mechanism-based absorption, distribution, and metabolism prediction tools.

The aim of this study was to assess a physiologically based modeling approach for predicting drug metabolism, tissue distribution, and bioavailability in rat for a structurally diverse set of neutral and moderate-to-strong basic compounds (n = 50). Hepatic blood clearance (CL(h)) was projected using microsomal data and shown to be well predicted, irrespective of the type of hepatic extraction model (80% within 2-fold). Best predictions of CL(h) were obtained disregarding both plasma and microsomal protein binding, whereas strong bias was seen using either blood binding only or both plasma and microsomal protein binding.

Understanding diffusion in confined systems: methane in a ZK4 molecular sieve. A molecular dynamics simulation study.

The equilibrium probability distribution of N methane molecules adsorbed in the interior of n alpha cages of the ZK4 zeolite, the all-silica analogue of zeolite A, is modeled by a modified hypergeometric distribution where the effects of mutual exclusion between particles are extracted from long molecular dynamics simulations. The trajectories are then analyzed in terms of time-correlation functions for the fluctuations in the occupation number of the alpha cages. The analysis digs out the correlations induced by the spatial distribution of the adsorbed molecules coupled with a migration mechanism where a molecule can pass from one alpha cage to another, one-by-one.

Liver enzyme elevation in hepatitis C virus (HCV)-HIV-coinfected patients prior to and after initiating HAART: role of HCV genotypes.

Transaminase elevation is frequently seen in hepatitis C virus (HCV)-HIV-coinfected patients receiving antiretroviral therapy (ART), representing an increase in the immune response against HCV and being one of the mechanisms proposed to be involved. There is a report claiming that HCV genotype 3 is an independent risk factor. Our objectives were to assess the incidence of liver toxicity in an HIV-HCV-coinfected population with relatively preserved cellular immunity, and the role of HCV genotypes in the elevation of liver enzymes, both at baseline and after initiating ART.

Hepatitis C viremia in HIV/HCV-coinfected patients: lower levels in presence of chronic hepatitis B.

Complex reciprocal interactions between hepatitis C (HCV) and hepatitis B (HBV) viruses (HBV) have been reported. We examined the influence of HBV on HCV RNA titers in 376 HCV/HIV-coinfected patients (30 were also HBsAg positive). Regression analyses identified negative HBsAg and male sex as factors associated with HCV RNA values >500,000 IU/mL.

[Amoxicillin-clavulanic acid and oral anticoagulants: a possible dangerous association].

We describe a 68-year-old male patient, treated with amoxicillin-clavulanic acid for 18 days and oral anticoagulants. He developed a cholestatic hepatitis with conjugated bilirubin of 11 mg/dL and a concomitant overdose of oral anticoagulants (INR 7). Nausea, vomiting, jaundice and large ecchymoses occurred 41 days after treatment with amoxicillin-clavulanic acid; the clinical manifestations resolved within 1 week and the liver tests returned to normal 48 days after therapy withdrawal.