Relapse of acquired hemophilia A following COVID-19.

Acquired hemophilia A (AHA) is a rare disease in which an autoantibody causes bleeding by interacting with and inhibiting the coagulation activity of endogenous factor VIII (FⅧ). Most cases of AHA are idiopathic, and other causes include autoimmune diseases, malignant tumors, pregnancy, drugs, and viral infections. An 86-year-old man was diagnosed with AHA based on the following results: activated partial thromboplastin time (aPTT) extension of 130.7 seconds, inhibitor pattern by mixing study, endogenous factor VIII (FⅧ) level at <1%, and FⅧ inhibitor titer at >5.1 Bethesda units (BU). The activity of von Willebrand factor (vWF) decreased (<10%), which was considered to be a complication of acquired von Willebrand syndrome (AVWS). The patient was started on prednisolone, and the inhibitor level eventually became negative. vWF values also became normal. However, 1 year later, he was hospitalized due to Coronavirus disease 2019 (COVID-19). His blood test showed an aPTT extension of 110.5 seconds, FⅧ level at 4%, and FⅧ inhibitor titer at 0.8 BU; thus, he was diagnosed with a relapse of AHA. After the administration of corticosteroid and remdesivir, he recovered from COVID-19 and AHA. The inhibitor level became negative on the 9th day of admission. Several articles have reported that COVID-19 infection and vaccination are implicated with AHA. We suggest that the aPTT should be measured when patients with AHA are infected with SARS-CoV2 to confirm AHA relapse.

COVID-19 and Thrombosis: Clinical Aspects.

In coronavirus disease 2019 (COVID-19), thrombus formation is related to the pathogenesis of acute respiratory distress syndrome (ARDS) and the progression of clinical symptoms. Severe damage to vascular endothelial cells and the associated cytokine storm after SARS-CoV-2 infection cause thrombogenesis and contribute to the development of more severe and unique thromboses compared to other infectious diseases. Thromboses occur more often in critically ill patients. In addition to pulmonary thromboembolism (PE) and deep vein thrombosis, acute myocardial infarction, peripheral arterial thrombosis, and aortic thrombosis have also been reported. In PE, thrombi develop in both pulmonary arteries and alveolar capillaries. These, together with intraalveolar fibrin deposition, interfere with effective gaseous exchange in the lungs and exacerbate the clinical symptoms of ARDS in patients with COVID-19. Pharmacological thromboprophylaxis is recommended for all hospitalized patients to prevent both thrombosis and aggravation of ARDS, and other organ failures. Although the pediatric population is mostly asymptomatic or develops mild disease after SARS-CoV-2 infection, a new inflammatory disorder affecting the cardiovascular system, multisystem inflammatory syndrome in children (MIS-C), has been reported. Similar to Kawasaki disease, acute myocarditis, coronary vasculitis, and aneurysms are typically seen in MISC, although these two are now considered distinct entities. A similar acute myocarditis is also observed in young male adults, in which a hyperinflammatory state after SARS-CoV-2 infection seems to be involved. Several side effects following vaccination against COVID-19 have been reported, including vaccine-induced immune thrombotic thrombocytopenia and acute myocarditis. Although these could be serious and life-threatening, the cases are very rare, thus, the benefits of immunization still outweigh the risks.

[Thrombosis with Thrombocytopenia Syndrome after ChAdOx1 nCoV-19 vaccination].

A 48-year-old Japanese man who had no previous medical history received his first dose of the ChAdOx1 nCoV-19 vaccine. Ten days after the vaccine administration, he developed a headache. Laboratory results indicated throm-bocytopenia and DIC. A head CT revealed microbleeding in the left parietal lobe. Contrast-enhanced CT showed thrombus in the left transverse sinus and left sigmoid sinus. A brain MRI demonstrated venous hemorrhagic infarction and subarachnoid hemorrhages in the left parietal lobe, and whole-body enhanced CT also revealed portal vein embolism and renal infarction. He was diagnosed with thrombosis with thrombocytopenia syndrome, and was treated according to the guideline. He has been recovering with the treatments. This is the first reported case of TTS associated with the ChAdOx1 nCoV-19 vaccine in Japan.

Time of Day of Vaccination Does Not Associate With SARS-CoV-2 Antibody Titer Following First Dose of mRNA COVID-19 Vaccine.

The immune system exhibits circadian rhythms, and its response to viral infection is influenced by the circadian clock system. Previous studies have reported associations between the time of day of vaccination against COVID-19 and production of anti-SARS-CoV-2 antibody titer. We examined the effect of vaccination time of day on anti-SARS-CoV-2 antibody titer after the first dose of vaccination with the mRNA-1273 (Moderna) COVID-19 vaccine in an adult population. A total of 332 Japanese adults participated in the present study. All participants were not infected with SARS-CoV-2 and had already received the first dose of mRNA-1273 2 to 4 weeks prior to participating in the study. The participants were asked to provide basic demographic characteristics (age, sex, medical history, allergy, medication, and mean sleep duration), the number of days after the first dose of vaccination, and the time of day of vaccination. Blood was collected from the participants, and SARS-CoV-2 antibody titers were measured. Ordinary least square regression was used for assessing the relationship between basic demographic characteristics, number of days after vaccination, time of day of vaccination, and the log10-transformed normalized antibody titer. The least square mean of antibody titers was not associated with the vaccination time and sleep durations. The least square means of antibody titers was associated with age; the antibody titers decreased in people aged 50 to 59 years and 60 to 64 years. The present findings demonstrate that the vaccination time with mRNA-1273 was not associated with the SARS-CoV-2 antibody titer in an adult population, suggesting that these results do not support restricting vaccination to a particular time of day. The present findings may be useful in optimizing SARS-CoV-2 vaccination strategies.

[COVID-19-associated coagulopathy].

In 2020, infection with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) rapidly spread across the world to become a global pandemic. Coronavirus disease-2019 (COVID-19) is associated with a high rate of coagulopathy and thrombotic complications. The underlying mechanisms involved in these processes are complex. In addition to the low physical activity, blood coagulation activation accompanied by excessive immune/inflammatory reactions and vascular endothelialitis associated with the presence of intracellular SARS-CoV-2 and disrupted cell membranes contribute substantially to the complexity of the mechanisms. The types of thrombosis that occur include arterial thrombosis and venous thromboembolism. Microthrombi in alveolar capillaries are observed in COVID-19 patients. Considering the possible involvement of thrombosis in the worsening of COVID-19, prophylactic anticoagulant therapy, such as low-molecular-weight heparin or unfractionated heparin, is essential for patients with moderate and severe infections. Even with prophylactic anticoagulant therapy, the incidence of thrombosis remains high. Consequently, control of the underlying inflammation and vascular endothelial protection may be required in combination with anticoagulant therapy.

The Japanese Medical Science Federation COVID-19 Expert Opinion English Version.

In 2020, the COVID-19 pandemic has had unprecedented impacts on various aspects of the world. Each academic society has published a guide and/or guidelines on how to cope with COVID-19 separately. As the one and only nationwide association of academic societies that represent medical science in Japan, JMSF has decided to publish the expert opinion to help patients and care providers find specifically what they want. This expert opinion is a summary of recommendations by many academic societies and will be updated when necessary. Patients that each academic society targets differ even though they suffer from the same COVID-19, and recommendations can be different in a context-dependent manner. Readers are supposed to be flexible and adjustable when they use this expert opinion.

COVID-19-Related Thrombosis in Japan: Final Report of a Questionnaire-Based Survey in 2020.

A questionnaire on COVID-19-related thrombosis in patients hospitalized before Aug 31, 2020, was sent to 399 hospitals throughout Japan. Responses were received from 111 (27.8%) with information on 6,202 COVID-19 patients. Of these, 333 and 56 required ventilation or extracorporeal membrane oxygenation (ECMO), respectively, and 212 died (3.4%). D-dimer levels were measured in 75.0% of the patients, revealing that 9.2% and 7.6% exhibited D-dimer increases of 3-8-fold and ≥8-fold the reference value, respectively. Thrombotic events occurred in 108 patients (1.86% of the 5,807 patients with available data) including symptomatic cerebral infarction in 24, myocardial infarction in 7, deep vein thrombosis in 41, pulmonary thromboembolism in 30, and other thrombotic events in 22. Some patients developed multiple thrombotic events. Thrombosis occurred in 32 patients with mild or moderate COVID-19 severity (0.59% of those with data available) and in 52 patients on ventilation or ECMO (13.5% of severe patients for whom data were available). Thrombosis occurred in 67 patients during worsening clinical condition and in 26 during recovery. Anticoagulant therapy was provided to 893 patients (14.6% of the 6,119 patients with available data), the main reasons being provided as elevated D-dimer levels and worsening clinical condition.