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Background. Heparin-induced thrombocytopenia (HIT) is a transient, antibody-mediated thrombocytopenia syndrome that usually follows exposure to unfractioned heparin (UFH) or low-molecular-weight heparin (LMWH). In contrast to other pathological conditions which lead to thrombocytopenia and bleeding complications, HIT results in a paradoxical prothrombotic state. It is caused by antibodies directed to complexes containing UFH or LMWH and a self-platelet protein: the platelet factor 4 (PF4). The heparin-PF4 immune complex leads to activation of platelets, monocytes, and endothelial cells which release procoagulant proteins and tissue factor with subsequent blood coagulation activation. Case Report. We describe the case of a woman undergone to knee replacement and affected by urosepsis who developed a HIT after exposure to enoxaparin. The thrombotic burden was very impressive involving the arterial and venous cerebral vessel and the venous pulmonary, hepatic, and inferior legs vascular beds. The patient was successfully treated with fondaparinux without recurrent thrombosis or bleeding. The clinical scenario could be named “catastrophic HIT” like the catastrophic antiphospholipid syndrome since they have a similar pathogenetic mechanism involving both platelets and monocytes procoagulant activities and a similar clinical manifestation with a life-threatening multiple arterial and/or venous thromboses. Conclusion. Patients presenting with HIT could show a very impressive thrombotic burden resembling to that of the catastrophic antiphospholipid syndrome. A careful differential diagnosis should be made towards other pathological conditions which lead to thrombocytopenia to avoid an unnecessary and potentially harmful platelet transfusion. Although fondaparinux is off-label, its use in patients with HIT is simple and seems to be effective.

Introduction: The recently published ACR/EULAR classification criteria score (3 points or more) both clinical and laboratory criteria to define the presence of antiphospholipid syndrome (APS). The clinical criteria have been better defined while laboratory criteria remain the same [lupus anticoagulant (LA), anticardiolipin (aCL) and anti ß2-Glycoprotein I (aß2GPI) antibodies] but with different impact (points) on the classification of patients. APS is excluded if more than 3 years separate positive test for antiphospholipid antibodies (aPL) and clinical manifestation., Methods: The present study evaluates how many patients would be excluded by the new criteria among those enrolled as APS in the START 2 antiphospholipid registry. The analysis includes 380 patients (274 APS and 106 carriers)., Results: Of 274 patients classified as APS, 118 (43%) did not match the new ACR/EULAR criteria for various reasons. First, the determination of aCL and aß2GPI antibodies was performed by automated instrumentations not allowed in the new criteria. Second, laboratory test score was less than 3 and this was due to an isolated IgM aCL or IgM aß2GPI in most cases and to isolated LA unconfirmed after 12 weeks in few cases. Third, 2 patients had a positive laboratory tests more than 3 years after the clinical event. Of the 106 carriers, 62% had aCL and aß2GPI determined by ELISA thus meeting the ACL/EULAR laboratory criteria but were negative for clinical criteria., Discussion: This study shows that many patients classified as APS in the START 2 registry do not match the classification using the new ACR/EULAR criteria., (© 2024 John Wiley & Sons Ltd.)

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. The median age at diagnosis was 67.8 (range: 15-93) years. Among the 41 patients, 10 (24%) cases were idiopathic, 4 (10%) were postpartum, 18 (44%) involved autoimmune diseases, and 9 (22%) involved a diagnosis of cancer., Results: The diagnostic delay exceeded 30 days in 15 of the 41 cases (36.5%). A total of 38 of the 41 (93%) patients presented with spontaneous bleeding, with mucocutaneous bleeding being the most common presentation (23/41, 56%). Four patients experienced postpartum bleeding. Clinical remission was achieved by 100% of patients and no patients died., Conclusion: Hemostatic and immunosuppressive therapy is essential in AHA, and it should be started as soon as possible in patients with bleeding. However, a significant delay in diagnosis was observed in these cases. The absence of mortality is likely attributable to the management of the disease within a specialized hemostasis and thrombosis unit, which offers a clinical ward, a specialized laboratory, and a dedicated ambulatory service. The Italian Society for the Study of Haemostasis and Thrombosis is working to secure recognition of this essential role in every hospital., Competing Interests: Conflict of Interest: No conflict of interest was declared by the authors., (©Copyright 2024 by Turkish Society of Hematology Turkish Journal of Hematology, Published by Galenos Publishing House.)

Context.—: Prothrombin time (PT) and activated partial thromboplastin time (aPTT) are coagulative screening tests used for the diagnosis of several pathologic conditions, such as liver failure, coagulation factor deficiencies, anti-phospholipid antibodies (lupus anticoagulant), and factor VIII inhibitors. A new test was developed several years ago to detect the amount of thrombin generated during plasma clotting, using low tissue factor concentrations and fluorogenic substrates, and it has since been used successfully in conditions ranging from hypocoagulable to hypercoagulable states. However, the test is expensive and difficult to perform in nonspecialized laboratories, and efforts have thus been made to find an economic and easily implementable test suitable for routine use, even in nonspecialist laboratories., Objective.—: To evaluate clot waveform analysis (CWA) of PT and aPTT, aiming to show the dynamics of clot formation; that is, the "hidden" features of both tests. CWA can be implemented by using an automated coagulometer with dedicated software. The aim of this review was to evaluate whether CWA is able to detect both hypercoagulative and hypocoagulative states., Data Sources.—: Using MedLine, we searched and retrieved articles relating to CWA. We only considered articles published in English, but with no limits in terms of article type, publication year, or geography., Conclusions.—: CWA was shown to be a reliable test in patients with both hypercoagulable and hypocoagulable states. It represents a simple and inexpensive global test that can easily provide information on the behavior of the coagulation system. Both the first and second derivatives are computed by using dedicated software implemented with an on-board algorithm in a routine automated coagulometer., Competing Interests: The authors have no relevant financial interest in the products or companies described in this article., (© 2024 College of American Pathologists.)

Background: Elderly populations face an increased risk of anemia, leading to elevated transfusion requirements during surgery, especially major orthopedic procedures. Anemia itself increases the risk of thromboembolic events, thus compounding complications in elderly individuals. Polypharmacy and the prevalent use of oral anticoagulants (OAC), particularly for atrial fibrillation, contribute to bleeding risks in this population. Data available in the literature on the peri-operative management of anemia in patients taking OAC is limited and often heterogeneous., Materials and Methods: This narrative case-based review focuses on the peri-operative management of elderly patients on OAC undergoing major orthopedic surgery. PubMed/Medline was used to search for relevant literature., Results: With reference to two cases, we critically evaluate the literature, and focus on risk factors, and preventive and therapeutic strategies as fundamental tools to reduce bleeding and correct anemia as soon as possible in elderly patients undergoing major orthopedic surgery., Discussion: Peri-operative management of these patients, especially those on OAC, requires a balanced approach considering bleeding and thrombotic risks. Intravenous iron therapy and tranexamic acid emerge as valuable strategies in minimizing transfusion requirements and optimizing patients' outcomes.

In the era of direct oral anticoagulants, vitamin K antagonists retain a clinically relevant role in thrombotic disorders. In Italy, approximately 20% of the patients on anticoagulant therapies receives a VKA, in most cases warfarin. The optimal management of this drug is challenging and cannot disregard its intricate and unpredictable pharmacokinetic properties and patient's thrombotic and bleeding risk. Several clinical issues encountered during warfarin treatment are still unanswered and are tentatively addressed by physicians. In this regard, the Italian Federation of Centers for the diagnosis of thrombotic disorders and the Surveillance of the Antithrombotic therapies (FCSA) provides some experience-based good clinical practice's suggestions on the following topics: (1) how to start the anticoagulant treatment with warfarin and warfarin induction regimen; (2) how to manage a subtherapeutic INR value; (3) how to manage a supratherapeutic INR value in asymptomatic patients; and (4) how to manage the association of warfarin with interfering drugs., Competing Interests: S.G. received honoraria for speaking at symposia from Pfizer and Daiichi-Sankyo and supports for attending meetings from Bayer, Daiichi-Sankyo, and Pfizer. P. B. received honoraria for lectures and/or participation on advisory board from Daiichi Sankyo, Pfizer, Bristol-Myers Squibb, Astra-Zeneca, Exeltis. D.B. received honoraria for lectures from Aspen and Werfen. C.A. received honoraria for lectures from Bayer. E.G. received honoraria for lectures from Sanofi and Italfarmaco, and for participation on advisory board from Roche, Sanofi Genzyme, and Novo Nordisk. G.M. received honoraria for lectures and for participation on advisory board: Bayer, Roche, Exeltis. G.R. declares no conflict of interest; A.S. received honoraria for lectures, manuscript writing, and/or participation on advisory board from Daiichi Sankyo, Bayer, Pfizer, Bristol-Myers Squibb, Boehringer Ingelheim, Sanofi, Werfen, Viatris, Alexion, and Roche. V.T. declared no conflict of interest. S.T. received honoraria for lectures and for participation on advisory board from Werfen, Stago, Italfarmaco, Pfizer, Bristol-Myers Squibb, and Sanofi. D.P. received honoraria for educational events from Pfizer, Daiichi-Sankyo, and Boehringer., (The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/).)

Competing Interests: None declared.

The development of oral contraceptives (OCs) began in 1921 and continued in the following years until the first regulatory approval from the Food and Drug Administration was granted in 1960. However, it took several years to realize that OCs presented an important but not frequent risk of venous thrombosis. Several reports ignored this dangerous effect and only in 1967 the Medical Research Council clearly stated this as an important risk. Later, research led to the formulation of second-generation OCs containing progestins, which nevertheless presented an increased thrombotic risk. In early 1980s, OCs containing third-generation progestins were introduced into the market. Only in 1995, it became clear that these new compounds induced a higher thrombotic risk than that related to the second-generation progestins. It appeared clear that the modulating action of progestins was against the procoagulant activity of estrogens. Lastly, at the end of the 2000s, OCs containing natural estrogens and a fourth-generation progestin (dienogest) became available. The prothrombotic effect of those natural products was not different from that of preparations containing second-generation progestins. Moreover, research over the years has produced much data on risk factors associated with OCs use such as age, obesity, cigarette smoking, and thrombophilia. These findings allowed us to better assess the individual thrombotic risk (both arterial and thrombotic) of each woman before offering an OC. Furthermore, research has shown that in high-risk people the use of single progestin is not dangerous as far as thrombosis is concerned. In conclusion, the OCs road has been long and difficult but has led to a great and unthinkable scientific and social enrichment since the 1960s., Competing Interests: None declared., (Thieme. All rights reserved.)

Introduction: Thrombophilia testing (TT) is a laboratory procedure designed to detect the risk factors involved in the pathogenesis of vascular occlusions. The role of TT is also controversial because it has a limited impact on the choice and duration of antithrombotic treatments., Areas Covered: We reviewed, by examining MEDLINE up to October 2023. Accepted and not accepted thrombophilia markers are discussed along with the appropriateness or not of prescribing TT in several conditions such as: provoked and unprovoked venous thromboembolism (VTE), women who are planning a pregnancy whose relatives had VTE or have a hereditary thrombophilia, before assumption of estro-progestins, after multiple pregnant loss, arterial thrombosis, retinal vein occlusion, and splanchnic vein thrombosis., Expert Opinion: TT is not essential in the management of VTE, but it may be useful for limiting adverse events in case of thrombophilia. We expose our criticism of items afforded by other guidelines by presenting our opinion based on both the scientific evidence and clinical practice. We also deal with common mistakes in prescribing and interpretations of TT hoping to purpose an educational approach on this topic. Finally, we emphasize the creation of the expert in hemostasis and thrombosis who should be present in every hospital.

Background: The main drawback of oral contraceptives (OC) and hormone replacement therapy (HRT) is an increased risk of venous and, to a lesser extent, arterial thrombosis., Materials and Methods: This narrative, case-based review describes the effect of available estrogens and progestogens on the hemostatic system and their potential impact on the risk of thrombosis. Clinical cases are used to illustrate different options for prescribing OC and HRT in the real-word. The aim is to offer discussion topics that could be helpful to guide the choice of different hormonal treatments over a woman's lifetime and in the presence of risk factors., Results: We describe physio-pathological changes occurring during the administration of hormonal therapies. Furthermore, we analyze the risk of venous and arterial thrombosis associated with different products, routes of administration and additional risk factors. New hormonal preparations, such as estradiol combined with dienogest, as well as non-oral hormonal therapies, are suggested to decrease thrombotic risk significantly., Discussion: The availability of many products and different routes of administration allow most women to safely use contraception, as well as HRT. We encourage careful counselling instead of inflexible or fearful behavior, as expanding options and choices will allow women to make the best decisions for their health.

Background: Direct oral anticoagulants (DOACs) are widely used in patients with atrial fibrillation and venous thromboembolism. The lack of the need for laboratory monitoring and a better safety than vitamin K antagonists (VKAs) has probably changed the quality of life of patients on these oral anticoagulants. This was a real-life prospective observational cohort study. The aim was to evaluate if a long-term treatment with DOACs could offer a better quality of life than VKAs. Moreover, age, gender, education level, time in therapeutic range for VKAs, taking medication once or twice a day for DOACs, the total daily number of medications and thrombotic and bleeding complications were considered as variables probably associated with the quality of life of these patients., Methods: Between January and December 2021, the Duke Anticoagulation Satisfaction Scale (DASS) 25-items was administered as an interview to patients on either VKAs or DOACs therapy. During the follow-up period, all of the patients were closely monitored to evaluate possible bleeding and thrombotic events., Results: The analysis included 300 outpatients treated with VKAs and 254 treated with DOACs. In general, the quality of life was better in patients taking DOACs (DASS total score: DOACs = 44.7, 42.9-46.5 vs. VKAs = 51, 49.2-52.8, p < 0.0001) as the daily-life limitations, hassles and burdens and the psychological impact were less important than in patients on VKAs therapy., Conclusions: VKAs negatively influence the daily-life of the patients in terms of both less satisfaction and time-consuming tasks. DOACs confer a better quality of life even if some concerns emerge from not knowing how their therapy is working.

Systemic sclerosis is a multisystem connective tissue disease, characterized by endothelial autoimmune activation, along with tissue and vascular fibrosis leading to vasculopathy and to a progressive loss of angiogenesis. This condition further deranges the endothelial barrier favouring the opening of the endothelial junctions allowing the vascular leak in the surrounding tissues: this process may induce cell detachment which allows the contact between platelets and collagen present in the exposed subendothelial layer. Platelets first adhere to collagen via glycoprotein VI and then, immediately aggregate because of the release of von Willebrand factor which is a strong activator of platelet aggregation. Activated platelets exert their procoagulant activity, exposing on their membrane phospholipids and phosphatidylserine, enabling the adsorption of clotting factors ready to form thrombin which in turn drives the amplification of the coagulative cascade. An essential role in the activation of blood coagulation is the tissue factor (TF), which triggers blood coagulation. The TF is found abundantly in the subendothelial collagen and is also expressed by fibroblasts providing a haemostatic covering layer ready to activate coagulation when the endothelial injury occurs. The aim of this review is to focus the attention on the underlying mechanisms related to haemostasis and thrombosis pathophysiology which may have a relevant role in SSc as well as on a possible role of anticoagulation in this disease., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

In this narrative review we report the main relationships between trace metals and the hemostatic system since this aspect has seldom attracted the attention of the scientific community. A basic aspect to be considered is the importance of maintaining the fine control of all trace metals' levels since they have an important impact on the pathophysiology of the hemostatic system. It is worth noting that poor diet habits are responsible for most trace metal deficiencies, while pollution is responsible for dangerous exposure to them with a consequent negative impact on the general population. This appears of paramount importance in planning the implementation of food and nutrient support to ameliorate the hidden hunger and the quality of life of people especially in developing countries and limiting poisons both in the air and food. As it often happens, when damage to certain mechanisms takes a very long time to appear, no attention is paid to the importance of a systematic prevention to avoid late negative outcomes., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)

Assisted reproductive techniques (ART) allow infertile couples to conceive. Use of hormones to obtain a controlled ovarian stimulation and an adequate growth of the endometrium preparatory for embryo implantation are not riskless. Among others, thrombotic events can occur during the ovulation induction or pregnancy following ART. As the number of women approaching ART to conceive is steadily increasing, the issue of thrombotic risk in this setting is relevant. Data on the weight of each risk factor and on potential benefit of thromboprophylaxis are largely lacking. In this review, we discuss risk of venous thromboembolism during pregnancy following ART, with a focus on general (i.e.: age, body mass index, thrombophilia, bed rest, transfusions) and ART-specific (i.e., polycystic ovarian syndrome, ovarian hyperstimulation syndrome) risk factors. We also attempt to provide some suggestions to guide clinical practice, based on available data and studies performed outside ART., Competing Interests: None declared., (Thieme. All rights reserved.)

Chronic spontaneous urticaria (CSU) is a disorder characterized by wheals and/or angioedema. The coagulation cascade and inflammation pathways are closely linked together. The aim of our study was first to investigate the dynamics of clot formation in plasma (Clot Waveform Analysis, CWA) in a group of 47 patients with CSU along with other coagulative parameters dedicated to the study of hypercoagulability, such as D-Dimer, F 1 + 2 peptide, Fibrinogen, Platelet count and Mean Platelet Volume (MPV). Secondly, 23 out of 47 patients were treated with Omalizumab at four administration intervals from T0 to T4. A statistically significant increase in Activated Partial Thromboplastin (aPTT) ratio, D-Dimer, F1 + 2, Platelet count and MPV was found when compared with 53 healthy controls (HC). In contrast, the 2nd Derivative of aPTT showed lower values than those of the HC. No differences were found between 1st derivative of aPTT and Fibrinogen. D-Dimer only showed a significant difference between T0 and T3. An activation of both coagulation and fibrinolysis along with a weaker clot acceleration may be in agreement with a low-grade DIC. The accelerated turnover of platelets expressed by both an increase in platelet count and MPV further supports this pathway in CSU. Omalizumab does not affect the relationship between the immune and the hemostatic systems., (© 2022. The Author(s).)

The prothrombin time (PT) and the activated partial thromboplastin time (aPTT) are two basic tests for routine purposes, which are widely used in the clinical screening of coagulopathies. PT and aPTT are useful tests for detecting both symptomatic (hemorrhagic) and asymptomatic defects, but they are unsuitable for studying hypercoagulable states. However, these tests are available for studying the dynamic process of clot formation by means of the detection of the clot waveform analysis (CWA), which has been introduced several years ago. CWA can provide useful information on both hypocoagulable and hypercoagulable states. Nowadays it is possible to detect the whole clot formation both in the PT and aPTT tubes starting from the initial step of fibrin polymerization by means of specific and dedicated algorithm implemented in a coagulometer. In particular, CWA provides information on the velocity (first derivative), acceleration (second derivative), and density (delta) of clot formation. CWA has been applied to several pathologic conditions such as coagulation factor deficiency (including congenital hemophilia from factor VIII, IX, or XI deficiency), acquired hemophilia, disseminated intravascular coagulation (DIC), sepsis, replacement therapy management, chronic spontaneous urticarial, and liver cirrhosis, in patients with high venous thromboembolic risk before LMWH prophylaxis, and in patients with different hemorrhagic patterns along with an electron microscopy evaluation of the clot density. We report here materials and methods used for detecting the additional clotting parameters available in both PT and aPTT., (© 2023. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

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., Methods: From December 2020 to January 2004, 1230 patients with venous thromboembolism or atrial fibrillation were enrolled. Age, gender, type of VKAs, clinical indications, INR values and bleeding events were recorded. TTR was calculated considering the entire period of treatment., Results: A total of 1616 and 1759 over-anticoagulation episodes were found in males and females, respectively. The median INR value was 4.5 (4.0-19.04). Thirty-two percent of the patients did not have an overdose throughout the observation period. The median number of over-anticoagulation per year was significantly higher in females (0.39-year) than in males (0.28-year). After 24 h of VKAs withdrawal, INRs were similar in both genders. Logistic regression analysis showed that the episodes of over-anticoagulation per year were associated with females, atrial fibrillation, warfarin therapy, follow-up length longer than 4 years, and TTR <73%, but were not associated to bleeding episodes., Conclusion: The higher number of over-anticoagulation can explain the lower TTR in females. An excess of anticoagulation is not associated with bleeding events. The recovery of INR performs better when acenocoumarol is used, therefore, in patients who present several episodes of over-anticoagulation, acenocumarolo could replace warfarin., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Patients on anticoagulant treatment are constantly increasing, with an estimated prevalence in Italy of 2% of the total population. About a quarter of the anticoagulated patients require temporary cessation of direct oral anticoagulants (DOACs) or vitamin K antagonists for a planned intervention within 2 years from anticoagulation inception. Several clinical issues about DOAC interruption remain unanswered: many questions are tentatively addressed daily by thousands of physicians worldwide through an experience-based balancing of thrombotic and bleeding risks. Among possible valuable answers, the Italian Federation of Centers for the diagnosis of thrombotic disorders and the Surveillance of the Antithrombotic therapies (FCSA) proposes some experience-based suggestions and expert opinions. In particular, FCSA provides practical guidance on the following issues: (1) multiparametric assessment of thrombotic and bleeding risks based on patients' individual and surgical risk factor, (2) testing of prothrombin time, activated partial thromboplastin time, and DOAC plasma levels before surgery or invasive procedure, (3) use of heparin, (4) restarting of full-dose DOAC after high risk bleeding surgery, (5) practical nonpharmacological suggestions to manage patients perioperatively. Finally, FCSA suggests creating a multidisciplinary "anticoagulation team" with the aim to define the optimal perioperative management of anticoagulation., Competing Interests: A.S.: Honoraria for lectures, manuscript writing, and/or participation on advisory board from Daiichi Sankyo, Bayer, Pfizer, Bristol-Myers Squibb, Sanofi, Werfen, Alexion, and Roche. D.P.: Honoraria for a webinar from Daiichi Sankyo. D.B.: Honoraria for lectures from Aspen and Werfen. A.C.: Honoraria for lectures from Bayer. E.G.: Honoraria for lectures from Sanofi and Italfarmaco, and for participation on advisory board from Roche, Sanofi Genzyme, and Novo Nordisk. C.M.: None. M.M.: Honoraria for lectures and manuscript writing from Daiichi-Sankyo. V.T.: Honoraria for lectures from Bayer and Novo Nordisk. A.T.: Honoraria for lectures from Werfen, Stago, and Roche; support for attending meetings from Novo Nordisk; honoraria for participation on advisory board from Bayer and Novo Nordisk. S.T.: Honoraria for lectures and for participation on advisory board from Werfen, Stago, Italfarmaco, Pfizer, Bristol-Myers Squibb, and Sanofi., (The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/).)

Vaccine-induced immune thrombotic thrombocytopenia (VITT) is a rare new syndrome occurring after the ChAdOx1 nCoV-19 vaccine immunization. Patients with VITT are characterized by a variable clinical presentation, likewise also the outcome of these patients is very variable. Here we report the lung ultrastructural findings in the course of VITT of a 58-year-old male patient. Alveoli were mainly dilated, irregular in shape, and occupied by a reticular network of fibrin, while interalveolar septa appeared thickened. The proliferation of small capillaries gave rise to plexiform structures and pulmonary capillary hemangiomatosis-like features. Near the alveoli occupied by a dense fibrin network, the medium-sized arteries showed a modified wall and an intraluminal thrombus. This scenario looks quite similar to that found during COVID-19, where the lungs suffer from the attack of the antigen-antibodies complexes and the virus respectively. In both diseases, the final outcome is a severe inflammation, activation of the haemostatic system and fibrinolysis.

Objective: The ongoing Coronavirus pandemic (COVID-19) showed similar characteristics with the severe acute respiratory syndrome (SARS). In the most compromised cases, COVID-19 infection leads to death due to severe respiratory complications. COVID-19-related acute respiratory distress syndrome (ARDS) is the primary cause of death in these patients. In the present study, we show an ultrastructural analysis on the lungs of a patient affected by COVID-19., Patients and Methods: Lung specimens obtained at autopsy from a 63-years old patient affected by COVID-19 were fixed in 1% paraformaldehyde. Slices of 300 µm thickness were dehydrated and dried by Critical Point Drying in CO2. Slices were covered with a conductive gold film approximately 30 nm thick and observed at a Zeiss Sigma 300 SEM FEG in the secondary electron (SE) and backscattered electron (BSE) modes. As case control a lung biopsy from a 60-year-old man was considered., Results: At low power in all COVID-19 lung specimens severe changes in the pulmonary architecture were found, due to the collapse of air spaces. Moreover, alveolar cavities were covered by large membranes. At high power, alveolar membranes showed a fibrillar structure, suggestive of a loose network of fibrin. It has been also found that intra-alveolar red blood cells were frequently present in the alveolar spaces, surrounded by a reticular fibrin network, suggestive for fibrin-hemorrhagic alveolitis. Alveolar changes were constantly associated with pathological features related to the pulmonary vessels. Vascular changes were prominent, including endothelial damage and thrombosis of large pulmonary vessels. Fibrinous microthrombi were frequently detected in the inter-alveolar septal capillaries. In addition, it has been frequently detected capillary proliferation in the alveolar septa with finding suggestive for intussusceptive neo-angiogenesis., Conclusions: In conclusion, our electron microscopy analysis showed that COVID-19-related lung disease is characterized by a substantial architectural distortion, with the interactions between alveolar and vascular changes. Intra-alveolar hyaline membranes are associated with macro- and micro-thrombotic angiopathy, ending with capillary proliferation. The new blood vessel formation originates from the septa and extends into the surrounding parenchyma. Our findings confirm previous reports on the specificity of the multiple and complex morphological pattern typical, and apparently specific, of COVID-19-related lung disease.

The risk stratification of young adults between subjects who will develop a mild form of atherosclerosis and subjects who will undergo a severe disease remains inaccurate. In the eighties of the previous century, David JP Barker has demonstrated the relationship between fetal conditions and occurrence of pathologies in adulthood. In this paper, the multiple evidence that might explain the increased susceptibility to severe forms of atherosclerosis, including stroke and cardiac infarct, in subjects who underwent intrauterine growth restriction (IUGR) will be analyzed. Specifically, we will review those inter-connected data indicating an association between a low weight at birth and an adult phenotype which might favor a severe outcome of atherosclerosis. Young and adult subjects born too small (IUGR) or too early (pre-terms) might represent a subgroup of "at risk subjects", more susceptible toward severe forms of atherosclerosis. Given that low birth weight (LBW) may be considered a surrogate of IUGR, this phenotypic feature could be considered among those indispensable clinical data collected in every patient presenting with atherosclerosis, irrespectively of age. According to the hypothesis that structural arterial changes might represent the link between LBW and susceptibility to atherosclerosis later in life, we suggest that the prevention of atherosclerosis should begin at birth. Regenerative and physiological substances such as thymosin Beta-4 could be challenged for a new "arterial regenerative medicine" in the perinatal period. The goal of this new approach should be the reinforcement of the structure of the arterial wall, allowing LBW newborns to avoid the most severe complications of atherosclerosis later in life: a dream that our research could contribute to bringing to life.

Arterial thromboembolic complications reported in patients with COVID-19 infection suggested that SARS-CoV-2 can trigger atherosclerotic plaque vulnerability. While endothelial cells in healthy subjects protect against thrombus formation, after injury they show prothrombotic activity. In addition, it has been hypothesized that "cytokine storm" might stimulate the production of neo-platelets triggering an abnormal "immunothrombosis" responsible for the hypercoagulable state induced in COVID-19 patients. The aim of this study is to report a case of severe COVID-19 infection characterized by the occurrence of microthrombosis in the vasa vasorum of the aorta. A 67-year-old male patient, in good health status and without comorbidities, who underwent a severe COVID-19 infection with fatal outcome, showed scattered aortic atherosclerotic plaques, characterized by multiple occlusive micro-thromboses in the vasa vasorum, spread out lymphocytic infiltrates and foci of endotheliitis and endothelial detachment. This case report confirms the previously described thrombotic involvement of vasa vasorum in COVID-19. The occurrence of the synchronous damage involving both the lumen surface (endothelial dysfunction, endotheliitis and endothelial detachment) and the adventitia (inflammation and occlusive thrombosis of vasa vasorum) could be the key points related to the fatal outcome of the SARS-CoV-2 patients. In our opinion, vasa vasorum thrombosis may thus initiate an atherogenic process that could be characterized by a much more rapid development.

Objective: Liver injury has been reported in patients with COVID-19. This condition is characterized by severe outcome and could be related with the ability of SARS-CoV-2 to activate cytotoxic T cells. The purpose of this study is to show the histological and scanning electron microscopy features of liver involvement in COVID-19 to characterize the liver changes caused by the activation of multiple molecular pathways following this infection., Patients and Methods: Liver biopsies from 4 patients (3 post-mortems and 1 in vivo) with COVID-19 were analyzed with histology and by scanning electron microscopy., Results: The liver changes showed significant heterogeneity. The first case showed ground glass hepatocytes and scattered fibrin aggregates in the sinusoidal lumen. The second evidenced intra-sinusoidal thrombi. The third was characterized by sinusoidal dilatation, atrophy of hepatocytes, Disse's spaces dilatation and intra-sinusoidal aggregates of fibrin and red blood cells. The fourth case exhibited diffuse fibrin aggregates in the dilated Disse spaces and microthrombi in the sinusoidal lumen., Conclusions: In COVID-19-related liver injury, a large spectrum of pathological changes was observed. The most peculiar features were very mild inflammation, intra-sinusoidal changes, including sinusoidal dilatation, thrombotic sinusoiditis and diffuse intra-sinusoidal fibrin deposition. These findings suggested that a thrombotic sinusoiditis followed by a local diffuse intra-vascular (intra-sinusoidal) coagulation could be the typical features of the SARS-CoV-2-related liver injury.

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. The secondary end-points were time of GIB appearance and the percentage of idiopathic or provoked events, i.e., bleeding due to a gastrointestinal disease. In case of GIB event all the patients were studied by means of endoscopic procedures. Cox regression was used to calculate the relative hazard ratios (HRs) of GIB for each considered clinical variable., Results: 734 patients on both VKAs or DOACs were studied. Overall, 46 hemorrhagic events were recorded: 6 were major bleeding (0.42/100 patient-years) while 43 were clinically relevant non major bleeding (2.8/100 patient-years). The Cox regression analysis did not show any relationships among GIB and the variables considered., Conclusion: The patients' clinical history is neither a predictor for GIB bleeding nor a guide to the choice of the oral anticoagulant to be administered. Routinely applying bleeding risk screening, such as occult blood in the stool, should be added to the periodic laboratory checks for early recognition of patients at higher risk of GIB., (Copyright © 2021 Elsevier B.V. All rights reserved.)

The risk stratification of young adults between subjects who will develop a mild form COVID-19 and subjects who will undergo a severe disease remains inaccurate. In this review, we propose that the Barker hypothesis might explain the increased susceptibility to severe forms of COVID-19 in subjects who underwent intrauterine growth restriction (IUGR). In this paper evidence indicating an association between a low birth weight and an adult phenotype which might favor a severe outcome of SARS-CoV-2 infection are presented: lower lung functional capacity; increased respiratory morbidity; changes in fibrinogen and Factor VII serum levels and dysregulation of the hemostasis and thrombosis system; acquisition of a pro-thrombotic phenotype; low nephron number, with decreased ability to sustain renal function and increased renal morbidity; heart remodeling, with a less efficient cardiac function; endothelial dysfunction, a risk factor for the insurgence of the multiple organ failure; remodeling of arteries, with changes in the elastic properties of the arterial wall, predisposing to the insurgence and progression of atherosclerosis; dysfunction of the innate immune system, a risk factor for immune diseases in adulthood. These data suggest that young and adult subjects born too small (IUGR) or too early (pre-terms) might represent a subgroup of "at risk subjects", more susceptible toward severe forms of COVID-19. Given that LBW may be considered a surrogate of IUGR, this phenotypic marker should be included among the indispensable clinical data collected in every patient presenting with SARS-COV-2 infection, irrespectively of his/her age.

Objective: In liver cirrhosis, a complex coagulopathy does exist. The aim was to investigate whether a possible chronic consumption coagulopathy is the underlying phenomenon of the disease., Patients and Methods: We measured endogenous thrombin generation with and without thrombomodulin (ETP ratio) along with D-Dimer in a group of consecutive 282 cirrhotic patients. Fibrinogen, Platelet count and the Hemorrhagic score were previously computed in the same patients. The ETP ratio represents the resistance to the anticoagulant activity of TM and should be considered as an index of a procoagulant imbalance., Results: ETP ratio and D-Dimer showed higher values in the cirrhotic patients when compared to controls thus showing a hypercoagulable state. When the patients were divided based on the Hemorrhagic score >7, we found that Fibrinogen, ETP ratio, D-Dimer and the platelet count were significantly different between the two groups. Again, when we considered ETP ratio >0.88, the median value of the cirrhotic patients, all parameters, were statistically different between the two groups. D-Dimer were higher while fibrinogen and platelet count were statistically lower in cirrhotic patients with higher ETP ratio values. Even when the same patients were divided based on their platelet count ( 100 x 109/L) the results showed a similar behavior. ROC curves showed significant AUCs when the hemorrhagic score was challenged against Fibrinogen, D-Dimer, Platelet count and ETP ratio., Conclusions: In liver cirrhosis hypercoagulable state is associated with an increase in D-Dimer levels along with a decrease in fibrinogen and platelet count thus indicating a low-grade intravascular coagulation which predicts a high hemorrhagic risk.

Objective: Vaccine-induced immune thrombocytopenia (VITT) is a new syndrome occurring primarily in healthy young adults, with a female predominance, after receiving the first dose of ChAdOx1 nCoV-19 vaccine. We describe VITT syndrome characterized by severe thrombosis and thrombocytopenia found in our patient, with fatal outcome., Case Report: A 58-year-old man, after 13 days from the first administration of ChAdOx1 nCoV-19 vaccine (AstraZeneca), presented with abdominal pain, diarrhea and vomitus. Laboratory tests revealed a severe thrombocytopenia, low fibrinogen serum levels and marked increase of D-dimer serum levels. The patient quickly developed a multiple organ failure, till death, three days after the hospital admission., Results: At histology, in the lungs, interalveolar septa appeared thickened with microthrombi in the capillaries and veins. Interalveolar septa appeared thickened and showed vascular proliferation. Thrombi were detected in the capillaries of glomerular tufts. In the hearth, thrombi were observed in veins and capillaries. In the liver, voluminous fibrin thrombi were diffusely observed in the branches of the portal vein. Microthrombi were also found in the vasa vasorum of the wall of abdominal aorta. In the brain, microthrombi were observed in the capillaries of the choroid plexuses. Diffuse hemorrhagic necrosis was observed in the intestinal wall with marked congestion of the venous vessels., Conclusions: In our patient, the majority of data necessary for a VITT final diagnosis were present: thrombocytopenia and thrombosis in pulmonary, portal, hepatic, renal and mesenteric veins, associated with a marked increase of D-dimer serum levels. The finding of cerebral thrombosis in choroid plexuses, is a new finding in VITT. These features are suggestive for a very aggressive form of VITT.

Study Question: What evaluation and care is offered to women after unexplained recurrent pregnancy loss (RPL) or intra-uterine foetal death (IUFD) and what are the reproductive outcomes?, Summary Answer: Women are assessed for thrombophilia and often treated with low-molecular weight heparin (LMWH) and/or low-dose aspirin (ASA)., What Is Known Already: Randomized controlled trials (RCTs) on possible efficacy of heparins and/or aspirin have been inconclusive due to limited power to detect a difference and patient heterogeneity., Study Design, Size, Duration: Prospective multicentre cohort study performed in 12 hospitals in three countries between 2012 and 2019., Participants/materials, Setting, Methods: All consecutive pregnant women with recurrent PL (≥3 losses or 2 losses in the presence of at least one euploid foetal karyotype) or at least one IUFD. Eligible women may have undergone thrombophilia testing before conception, at the discretion of local providers. The possible assignment of women to treatments (such as LMWH) was not decided a priori but was determined based on the responsible provider's current practice. Aims of the study were: (i) to evaluate factors associated with pregnancy outcome; (ii) to compare clinical management strategies in women with and without a subsequent successful pregnancy; and (iii) to evaluate characteristics of women who may benefit from antithrombotic therapy. A propensity score matching method was used to balance the differences in baseline characteristics., Main Results and the Role of Chance: A matched sample of 265 pregnant women was analysed, with all undergoing thrombophilia screening; 103 out of 119 (86.6%) with and 98/146 (67.1%) without thrombophilia were prescribed with LMWH and/or ASA. Overall, live-births were recorded in 204 cases (77%), PL or IUFD in 61 (23%) pregnancies. Logistic regression showed a significant interaction between thrombophilia and treatment with LMWH (P = 0.03). Findings from sensitivity analysis showed odds ratio (OR) for pregnancy loss in women with inherited or acquired thrombophilia in absence of any treatment was 2.9 (95% CI, 1.4-6.1); the administration of LMWH (with or without ASA) was associated with higher odds of live-birth (OR, 10.6; 95% CI, 5.0-22.3). Furthermore, in women without thrombophilia, the odds of live-birth was significantly and independently associated with LMWH prophylaxis (alone or in association with ASA) (OR, 3.6; 95% CI, 1.7-7.9)., Limitations, Reasons for Caution: While the propensity score matching allows us to balance the differences in baseline characteristics, it does not eliminate all confounding., Wider Implications of the Findings: Antithrombotic prophylaxis during pregnancy may be effective in women with otherwise unexplained PL or IUFD, and even more useful in those with thrombophilia., Study Funding/competing Interest(s): The study was funded by Italian Ministry of Health (Ricerca Corrente 2018-2020). Dr G.P. has received research grant support from Bristol Myers Squibb/Pfizer Alliance, Janssen, Boston Scientific Corporation, Bayer, and Portola and consultant fees from Amgen and Agile Therapeutics. Dr E.G. has received consultant fees from Italfarmaco and Sanofi. All other authors declare that they have no conflict of interest., Trial Registration Number: NCT02385461., (© The Author(s) 2021. Published by Oxford University Press on behalf of European Society of Human Reproduction and Embryology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Background: Patient's adherence to oral anticoagulant therapy is essential to prevent and treat thrombotic events., Methods: To assess the patients' adherence Morisky Medication Adherence Scale 8-items was used. The target population included 785 consecutive outpatients, of whom 384 were on Vitamin K Antagonists and 401 on Direct Oral Anticoagulants. Moreover, we evaluate which variable among age, gender, having experienced a thrombotic episode, time in the therapeutic range for patients on Vitamin K Antagonists, being naive and once versus twice daily drug assumption for patients on Direct Oral Anticoagulants, could affect adherence to therapy., Results: Morisky Medication Adherence Scale 8-items score was 8 in both groups. The intentional non-adherence obtained the lowest score while the unintentional non-adherence is the most frequent problem in patients treated with either Vitamin K Antagonists or Direct Oral Anticoagulants. Age > 75 years, male gender, having experienced a thrombotic episode, being naive and assuming Direct Oral Anticoagulants twice a day were significantly associated with a higher risk to forget assuming the oral anticoagulant, to have more difficulty in remembering to take it or to bring it in case of travel or leaving home. A low percentage of time in therapeutic range was associated with a not regularly assumption of the anticoagulants., Conclusion: Patients treated with Vitamin K Antagonists or Direct Oral Anticoagulants show a good adherence and persistence to their oral anticoagulant therapy. Several factors have been identified to affect patients' adherence and deserve a careful attention by the doctors at the Anticoagulation Clinic., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Objective: Wilson's Disease (WD) is an autosomal recessive copper overload. Several mutations of the copper pump named ATP7B have been involved. WD is difficult to diagnose mainly because of its heterogeneity of presentation. The histologic spectrum is wide and not specific, ranging from very mild changes to severe disease. The histological picture of WD may overlap different conditions, including ALD, NAFLD, viral hepatitis or autoimmune liver disease., Patients and Methods: We describe our experience on WD based on a single-center series of liver biopsies. One-hundred twenty-seven liver samples from 43 Sardinian WD patients were reviewed. The most reported pattern was steatohepatitis, accounting 82/127 biopsies (64.6%), followed by hepatitis in 25 biopsies (19.7%), and steatosis in 20 biopsies (15.7%)., Results: As for the elementary lesions, inflammation, steatosis, glycogenated nuclei and ballooning were the most frequent, being found in 107, 102, 90 and 86 biopsies out of the 127. Notably, all these lesions showed a predominant periportal location. There was no significant difference in the diagnostic pattern or in each elementary lesion between the biopsies performed at presentation and those performed during the follow-up. Lipogranuloma (significantly more numerous in the follow-up biopsies) and fibrosis (likewise significantly progressed in follow-up biopsies) were the only exceptions., Conclusions: Our data confirm the variability of the histological pattern in WD. However, the preferential localization of steatosis and balloon cells in periportal zone can be a useful clue for the diagnosis of WD.