D-dimer testing: A narrative review.

D-dimer containing species are soluble fibrin degradation products derived from plasmin-mediated degradation of cross-linked fibrin, i.e., 'D-dimer'. D-dimer can hence be considered a biomarker of in vivo activation of both coagulation and fibrinolysis, the leading clinical application in daily practice of which is ruling out venous thromboembolism (VTE). D-dimer has been further evaluated for assessing the risk of VTE recurrence and helping define optimal duration of anticoagulation treatment in VTE, for diagnosing disseminated intravascular coagulation (DIC), and for screening those at enhanced risk of VTE. D-dimer assays should however be performed as intended by regulatory agencies, as their use outside these indications might make them a laboratory-developed test (LDT). This narrative review is aimed at: (1) reviewing the definition of D-dimer, (2) discussing preanalytical variables affecting D-dimer measurement, (3) reviewing and comparing the assays performance and some postanalytical variables (e.g., different units and age-adjusted cutoffs), and (4) discussing the interest of D-dimer measurement across different clinical settings, including pregnancy, cancer, and coronavirus disease 2019 (COVID-19).

Incidence and impact of anticoagulation-associated abnormal menstrual bleeding in women after venous thromboembolism.

Preliminary data and clinical experience have suggested an increased risk of abnormal uterine bleeding (AUB) in women of reproductive age treated with anticoagulants, but solid data are lacking. The TEAM-VTE study was an international multicenter prospective cohort study in women aged 18 to 50 years diagnosed with acute venous thromboembolism (VTE). Menstrual blood loss was measured by pictorial blood loss assessment charts at baseline for the last menstrual cycle before VTE diagnosis and prospectively for each cycle during 3 to 6 months of follow-up. AUB was defined as an increased score on the pictorial blood loss assessment chart (>100 or >150) or self-reported AUB. AUB-related quality of life (QoL) was assessed at baseline and the end of follow-up using the Menstrual Bleeding Questionnaire. The study was terminated early because of slow recruitment attributable to the COVID-19 pandemic. Of the 98 women, 65 (66%) met at least one of the 3 definitions of AUB during follow-up (95% confidence interval [CI], 57%-75%). AUB occurred in 60% of women (36 of 60) without AUB before VTE diagnosis (new-onset AUB; 95% CI, 47%-71%). Overall, QoL decreased over time, with a mean Menstrual Bleeding Questionnaire score increase of 5.1 points (95% CI, 2.2-7.9), but this decrease in QoL was observed only among women with new-onset AUB. To conclude, 2 of every 3 women who start anticoagulation for acute VTE experience AUB, with a considerable negative impact on QoL. These findings should be a call to action to increase awareness and provide evidence-based strategies to prevent and treat AUB in this setting. This was an academic study registered at www.clinicaltrials.gov as #NCT04748393; no funding was received.

2022 international clinical practice guidelines for the treatment and prophylaxis of venous thromboembolism in patients with cancer, including patients with COVID-19

The International Initiative on Thrombosis and Cancer is an independent academic working group of experts aimed at establishing global consensus for the treatment and prophylaxis of cancer-associated thrombosis. The 2013, 2016, and 2019 International Initiative on Thrombosis and Cancer clinical practice guidelines have been made available through a free, web-based mobile phone application. The 2022 clinical practice guidelines, which are based on a literature review up to Jan 1, 2022, include guidance for patients with cancer and with COVID-19. Key recommendations (grade 1A or 1B) include: (1) low-molecular-weight heparins (LMWHs) for the initial (first 10 days) treatment and maintenance treatment of cancer-associated thrombosis;(2) direct oral anticoagulants for the initial treatment and maintenance treatment of cancer-associated thrombosis in patients who are not at high risk of gastrointestinal or genitourinary bleeding, in the absence of strong drug-drug interactions or of gastrointestinal absorption impairment;(3) LMWHs or direct oral anticoagulants for a minimum of 6 months to treat cancer-associated thrombosis;(4) extended prophylaxis (4 weeks) with LMWHs to prevent postoperative venous thromboembolism after major abdominopelvic surgery in patients not at high risk of bleeding;and (5) primary prophylaxis of venous thromboembolism with LMWHs or direct oral anticoagulants (rivaroxaban or apixaban) in ambulatory patients with locally advanced or metastatic pancreatic cancer who are treated with anticancer therapy and have a low risk of bleeding.

The role of platelets in antiviral immunity

The main role of platelets is traditionally assigned to participation in hemostasis reactions. In recent years, the data have appeared on the non-hemostatic platelet-related role and their active participation in inflammatory reactions. These platelet functions are predetermined by their ability to activate and secrete various immunomodulatory cytokines and chemokines. In addition, activated platelets can directly interact with viral receptors. Recently, there has been growing the knowledge regarding platelet-related regulation of diverse cell types. The result of this interaction is, among others, the formation of platelet-leukocyte aggregates, the focusing of neutrophils at the sites of injury, and generation of a scaffold for developing extracellular traps. Thus, platelets are not only participants in coagulation processes, but also important players in the inflammatory process. This lecture details the issues of platelets controlling and modulating host response to viral infection, as well as potential targets for therapeutic intervention.

Venous thromboembolism risk, prophylaxis and management in cancer patients with COVID-19: An unmet medical need

Cancer patients exhibit an increased risk of venous thromboembolism (VTE), with VTE being the second leading cause of morbidity and mortality in these patients. The implementation of lockdowns following the COVID-19 pandemic has resulted in decreased mobility and delayed access to care, thus further increasing the susceptibility to VTE. Cancer patients may also be at a higher risk of SARS-CoV-2 infection and have been shown to be more likely to experience severe COVID-19 disease compared to patients without cancer. Given that both cancer and COVID-19 exhibit a hypercoagulable state, stasis of blood flow, and endothelial injury, cancer patients with COVID-19 constitute a vulnerable population with a high risk of thrombosis and bleeding. However, to date there are limited studies evaluating whether cancer patients infected with SARS-CoV-2 have a higher VTE incidence than COVID-19 patients without cancer, how to assess the risk of VTE, prophylaxis and treatment in this special population. Herein, we highlight the urgent need for studies in cancer patients with COVID-19 to ensure appropriate patient care and improve clinical outcomes. © 2022 The Authors

Vaccine-induced immune thrombotic thrombocytopenia: Definition, risks with different vaccines, and the regulators’ responses

After the vaccination campaign initiation in Europe and the UK, reports of rare cases of atypical thrombosis, including sinus vein thrombosis and splanchnic venous thrombosis, began to appear in association with the use of AstraZeneca (ChAdOx1) and J&J/Janssen adenovirus vector vaccines. The syndrome called VITT (vaccine-induced immune thrombotic thrombocytopenia) is manifested as thrombosis simultaneously with decreased platelet count, significantly increased D-dimer levels and detected anti-factor 4 platelet (PF4) antibodies. We present a detailed review on the epidemiology, pathogenesis, clinical picture, diagnostics and treatment of VITT, which by its nature is an immune complication similar to the processes occurring in heparin-induced thrombocytopenia (HIT). All international and national organizations and regulatory authorities, including experts in the field of thrombosis and hemostasis and the VITT expert council recommend continuing the prompt mass vaccination against COVID-19 as the only method able to reduce the incidence of severe cases, stop the spread of COVID-19 infection and emergence of new dangerous mutations in the viral genome. Failure to vaccinate poses an incomparably greater risk of fatal thrombotic and inflammatory complications associated with infections, compared with the risks of extremely rare adverse events that can occur after vaccination. It should be noted that information on VITT, described as a sporadic phenomenon of abnormal immune response to some variants of vaccines against COVID-19, cannot be translated to other vaccines (including those registered in the Russian Federation) and, moreover, cannot be a reason to refuse their administration. © 2021 Obstetrics, Gynecology and Reproduction. All rights reserved.

Thrombotic storm, hemostasis disorders and thromboinflammation in COVID-19

The rate of thrombosis and disseminated intravascular coagulation (DIC) has been increasing in COVID-19 patients. Key features related to such condition include minimal or no risk of bleeding, moderate thrombocytopenia, high plasma fibrinogen as well as increased complement components level in the areas of thrombotic microangiopathy. The clinical picture is not typical for classic DIC. This review systematizes the pathogenetic mechanisms of hypercoagulation in sepsis and its extreme forms in patients with COVID-19. The latter consist of the thrombosis-related immune mechanisms, the complement activation, the macrophage activation syndrome, the formation of antiphospholipid antibodies, the hyperferritinemia, and the dysregulation of the renin-angiotensin system. Taking into consideration the pathogenetic mechanisms, the biomarkers had been identified related to the prognosis of the disease development. Patients with pre-existing cardiovascular disease and other risk factors, including obesity, diabetes, hypertension, and aging pose the peak risk of dying from COVID-19. We also summarize new data on platelet and endothelial dysfunction, immunothrombosis, and, as a result, thrombotic storm as essential components of COVID-19 severe features. © 2021 Obstetrics, Gynecology and Reproduction. All rights reserved.