[Acquired hemophilia A following BNT162b2 mRNA COVID-19 vaccination].

Acquired hemophilia A (AHA) is a rare disease characteized by bleeding symptoms caused by decreased factor VIII activity due to the appearance of inhibitors to factor VIII triggered by malignancy or collagen disease. An 86-year-old woman developed purpura on her extremities after the first dose of the BNT162b2 mRNA COVID-19 vaccine. This symptom subsided after a few days. After the second dose of the BNT162b2 mRNA COVID-19 vaccine, purpura appeared again, and the patient was referred to our hospital Her APTT was remarkably prolonged to 110 seconds, and a cross-mixing test revealed an inhibitor pattern. Since FVIII activity was <1% and FVIII inhibitor was 51.6 BU, she was diagnosed with AHA. Prednisolone therapy was started, and coagulative complete remission was achieved. Because acquired hemophilia can develop after mRNA COVID-19 vaccination, as in this case, it is critical to monitor the appearance of bleeding symptom.

[Hemostatic management of hemophilia].

Replacement therapy is the basic treatment for hemophilia by infusing deficient clotting factors, including replacement therapy for prophylaxis (i.e., prevention of breakthrough bleeding for physical activity), episodic replacement therapy, replacement therapy during and after procedures and surgery, and replacement therapy for physical activity, each administered at doses and intervals appropriate for the purpose and the product used. Although emicizumab is increasingly used for prophylaxis in severe hemophilia A, the combination of replacement therapy is necessary, especially during severe bleeding, highly invasive procedures, and major surgery. Furthermore, the usual APTT measurements cannot be used for monitoring the replacement therapy and detecting the presence of inhibitors while patients are receiving emicizumab. Hemostatic management of patients with inhibitors should be implemented based on the purpose of the therapy, the latest inhibitor titer, and the clinical response to the product, with the choice of inhibitor neutralization or bypass agent therapy. When bypassing agents are used in patients with hemophilia A with emicizumab inhibitor during and after bleeding, procedures, and surgery, the choice of agent and dose adjustment should be made with attention to thrombotic complications.

Acquired haemophilia A in a patient with breast cancer and lung carcinoma: a case report and literature review.

Acquired haemophilia A is a rare disorder caused by spontaneous formation of auto-antibodies (inhibitors) against coagulation factor VIII. This can lead tolife-threatening haemorrhages. Six to twenty-two percent of patients with acquired haemophilia have an underlying malignancy. We describe a 69-year-old woman with metastatic breast cancer and non-small cell lung carcinoma who presented at the emergency room with spontaneous bruising, and who was using a vitamin K antagonist. She had a prolonged activated partial thromboplastin time (aPTT) due to a coagulation factor VIII deficiency caused by factor VIII antibodies. She was treated with prednisone and cyclophosphamide.

[Acquired hemophilia A with high-titer factor VIII inhibitor developing subsequent to clopidogrel administration].

An 80-year-old male was referred to our department for prolonged APTT (activated partial thromboplastin time) and subcutaneous hemorrhage. His medical history comprised alcoholic liver cirrhosis, hepatocellular carcinoma (HCC), and peripheral artery disease (PAD). For refractory HCC, he had received transcatheter arterial chemoembolization and was followed up regularly at our hospital. He underwent percutaneous transluminal angioplasty for PAD 10 months ago, and dual antiplatelet therapy with clopidogrel and cilostazol was initiated. Cilostazol was discontinued owing to subcutaneous hemorrhage 6 months ago. The prolonged APTT level, inhibitor pattern by cross-mixing test, and the presence of the inhibitor against factor VIII (449 Bethesda unit/ml) corroborated acquired hemophilia A (AHA). Thus, clopidogrel was discontinued for possible drug-induced AHA. After 4-week oral corticosteroid therapy, the APTT level recovered to normal. This case highlights two distinct features as follows: (1) possible relation to clopidogrel; and (2) despite extremely high titer of factor VIII inhibitor, his bleeding episodes were managed without antihemorrhagic agents. Here we present a case of clopidogrel-related AHA. Further accumulation of such cases is warranted to determine the potential correlation with clopidogrel and AHA.

Development of acquired haemophilia A in a patient treated with alemtuzumab for multiple sclerosis.

This case illustrates a 36-year-old man who presented with a factor VIII (FVIII) inhibitor (acquired haemophilia A) with cutaneous bleeding and a significant thigh haematoma. No traditional risk factors for the development of a FVIII inhibitor were identified. However, previous treatment with alemtuzumab for multiple sclerosis was noted in the patient's history. Alemtuzumab is an anti-CD52 monoclonal antibody and is known to be associated with the development of a number of autoimmune conditions, with a delay in onset of these conditions as long as 5 years after the cessation of treatment. To our knowledge, there have only been three previously documented cases of a FVIII inhibitor in the setting of alemtuzumab therapy. This case adds further evidence to the current body of literature suggesting alemtuzumab as a causative agent for the development of an FVIII inhibitor.

Acquired haemophilia A complicating alemtuzumab therapy for multiple sclerosis.

Alemtuzumab is a highly efficacious therapy used in the treatment of multiple sclerosis (MS), but uncoupling of T and B cell repopulation during immune reconstitution associates with an increasing range of secondary B cell-mediated autoimmune complications. A 34-year-old woman developed Graves' disease 11 months following an initial course of alemtuzumab treatment for MS. Nine months following the second treatment with alemtuzumab, the patient presented with spontaneous intramuscular and subcutaneous haemorrhage due to development of an inhibitory autoantibody to coagulation factor VIII. Acquired haemophilia A (AHA) is an extremely rare complication in patients treated with alemtuzumab. Treatment with rituximab may induce a rapid remission of AHA; however, the patient's high John Cunningham virus (JCV) antibody index and alemtuzumab-induced T cell lymphopenia may lead to an increased risk of progressive multifocal leucoencephalopathy, a potential complication which was unacceptable to the patient.

Aspirin unmasking acquired haemophilia A in a patient with prostate cancer.

A 72-year-old man, on treatment for prostate cancer, attended the emergency department with his 2nd episode of spontaneous extensive bruising and haematomas. His first presentation was 2 months prior but this was thought to be because of his aspirin and he improved when aspirin was discontinued. On this occasion aspirin had been restarted 7 days before he developed his symptoms. His blood investigation was significant for a much raised activated partial thromboplastin time (aPTT). On his 3rd day of admission he deteriorated clinically with a drastic drop in his haemoglobin and worsening tense haematomas. Blood investigations confirmed the diagnosis of acquired factor VIII deficiency and he subsequently received treatment with factor VIII inhibitor bypassing activity, steroids and immunosuppresants.

Development of acquired hemophilia A during treatment of multiple myeloma with lenalidomide.

We describe a 67-year-old female demonstrating symptomatic multiple myeloma (MM) with anemia and bone lesions initially diagnosed in 2009. Although a partial response was achieved after bortezomib and dexamethasone treatment, MM recurred in 2012. Therefore, treatment with lenalidomide, cyclophosphamide, and dexamethasone was commenced. Coagulation tests conducted prior to the chemotherapy were normal. Lenalidomide was discontinued after 10 days due to exacerbation of renal dysfunction. Simultaneously, activated partial thromboplastin time (APTT) was prolonged to 89.5 seconds. The mixing test showed an inhibitor pattern, with factor VIII at 2% and factor VIII inhibitor at 4.85 BU/ml. A diagnosis of acquired hemophilia A was made, and treatment with prednisolone was started, after which APTT improved to 36.4 seconds and factor VIII inhibitor decreased to 1.09 BU/ml. The factor VIII inhibitor level again increased concomitantly with restarting lenalidomide, which was, therefore, discontinued, while immunosuppressive therapy was administered with the addition of cyclophosphamide. Factor VIII inhibitor gradually disappeared from the patient's blood over the next four months. To the best of our knowledge, this is the first description of lenalidomide as a possible cause of acquired hemophilia A. Our experience indicates that we need to pay attention to acquired hemophilia A after initiating lenalidomide therapy in patients with hematologic malignancies.

Acquired coagulant factor VIII deficiency induced by Bacillus anthracis lethal toxin in mice.

Mice treated with anthrax lethal toxin (LT) exhibit hemorrhage caused by unknown mechanisms. Moreover, LT treatment in mice induced liver damage. In this study, we hypothesized that a suppressed coagulation function may be associated with liver damage, because the liver is the major producing source of coagulation factors. The hepatic expression of coagulant factors and the survival rates were analyzed after cultured cells or mice were exposed to LT. In agreement with our hypothesis, LT induces cytotoxicity against hepatic cells in vitro. In addition, suppressed expression of coagulation factor VIII (FVIII) in the liver is associated with a prolonged plasma clotting time in LT-treated mice, suggesting a suppressive role of LT in coagulation. Accordingly, we further hypothesized that a loss-of-function approach involving treatments of an anticoagulant should exacerbate LT-induced abnormalities, whereas a gain-of-function approach involving injections of recombinant FVIII to complement the coagulation deficiency should ameliorate the pathogenesis. As expected, a sublethal dose of LT caused mortality in the mice that were non-lethally pretreated with an anticoagulant (warfarin). By contrast, treatments of recombinant FVIII reduced the mortality from a lethal dose of LT in mice. Our results indicated that LT-induced deficiency of FVIII is involved in LT-mediated pathogenesis. Using recombinant FVIII to correct the coagulant defect may enable developing a new strategy to treat anthrax.

Acquired hemophilia with inhibitors presenting as an emergency: misinterpretation of clotting results during direct oral anticoagulation.

BACKGROUND: Direct oral anticoagulants (DOACs) were recently introduced and are being increasingly prescribed. Most DOACs alter the values of traditional coagulation tests, such as the international normalized ratio (INR) or the activated partial thromboplastin time (aPTT). Although vitamin K antagonists raise the INR value to an extent that mirrors their anticoagulant effect, DOACs do not, in general, alter standard clotting values in any consistent way. Thus, there is a risk that abnormal INR and aPTT values can be misinterpreted. CASE ILLUSTRATION: A woman taking rivaroxaban, a DOAC, presented with ileus and was scheduled for urgent surgery. A prolonged aPTT was, at first, wrongly attributed to rivaroxaban, delaying the correct diagnosis of autoantibody-associated acquired hemophilia (a rare condition with incidence, 1.34-1.48 cases per million people per year). The patient had a history of unusually intense bleeding in the skin and mucous membranes during anticoagulant treatment. Her aPTT had been prolonged even before any anticoagulants were taken. COURSE: The operation was delayed to await the elimination of rivaroxaban. The aPTT was still prolonged 24 hours later. The diagnosis of autoantibody-associated acquired hemophilia was suspected and then confirmed by the measurement of a factor VIII residual activity of 1% and the demonstration of factor VIII inhibition at an intensity of 9.2 Bethesda units per mL. CONCLUSION: The causes of abnormal clotting test results must be clarified before beginning anticoagulant therapy. Unusually intense bleeding during oral anticoagulation should arouse suspicion of a previously undiagnosed acquired coagulopathy, e.g., antibody-associated acquired hemophilia.

Desvenlafaxine as a possible cause of acquired hemophilia.

OBJECTIVE: Acquired hemophilia A (AHA) is characterized by the depletion of Factor VIII mediated by specific autoantibodies. While the cause is unknown in 50% of the cases, an association with malignancy, peripartum period, autoimmune disease and the use of drugs has been described. We report a case of AHA possibly induced by desvenlafaxine. CASE REPORT: Mr. P, a 70-year-old Caucasian male with alcohol and opioid dependence in remission, was started on 50 mg of desvenlafaxine for a moderate depressive episode. After 10 weeks, he developed an ecchymosis of the right upper extremity, in the absence of past or family history of bleeding disorder. He had a prolonged activated partial thromboplastin time (74.5 s) not corrected on performing mixing study, decreased Factor VIII activity (< 1%) and detectable Factor VIII inhibitor (30 Bethesda units) confirming a diagnosis of AHA. After all other causes were ruled out, desvenlafaxine was discontinued and the patient was infused with Factor VIIa followed by a 6-week prednisone taper with which he achieved remission. DISCUSSION: While serotonin inhibitors are known to impair platelet aggregation leading to bleeding, abnormalities in the coagulation cascade have not been described so far. Desvenlafaxine appears to be the probable cause of AHA given the temporal association, remission after withdrawal of the drug and the lack of any other probable cause. New-onset abnormalities of the coagulation cascade such as AHA should be considered in the context of bleeding events with desvenlafaxine and perhaps other serotonin inhibitors, given the significant mortality rates when untreated.

Acquired factor VIII inhibitors: case reports of paclitaxel and penicillin-induced entities.

Acquired hemophilia A is an uncommon but potentially life-threatening clinical entity mediated by specific autoantibodies direct against coagulation factor VIII. It may be associated with a number of conditions such as solid malignancies, autoimmune diseases, lymphoproliferative disorders, and drugs. Early recognition of this entity is necessary to avoid a delay in treatment, which might lead to serious complications including severe bleeding and death. Hereby, we report a case of acquired hemophilia A caused by a commonly used drug, penicillin, as well as the first reported case, to our knowledge, of acquired Factor VIII inhibitor secondary to paclitaxel.

Drug-induced anti-factor VIII antibodies: a systematic review.

Acquired hemophilia A is an uncommon but potentially life-threatening hemorrhagic disorder caused by the onset of autoantibodies against coagulation factor VIII. Acquired hemophilia A is most frequently associated with autoimmune diseases, solid tumors, lymphoproliferative diseases, pregnancy, and drug reactions. However, in approximately 50 percent of the patients no underlying disorder can be identified. Prompt diagnosis of this acquired bleeding disorder is essential for appropriate management aimed to control hemorrhage and suppress the inhibitor. Based on electronic and manual searches of the published literature, this review examines the current knowledge on drug-induced factor VIII autoantibodies. A total of 34 cases were identified, mostly related to a variety of agents, including antibiotics and psychiatric and immunomodulatory drugs. In particular there is increased evidence for an association between acquired hemophilia A and interferon given as treatment for hepatitis C virus infection. Although most inhibitors reported in the literature were at high titers (mean: 67.7 Bethesda Units/ml), their prognosis was good, as they disappeared in most cases after suspension of the involved drug or after immunosuppressive therapy (complete remission rate: 83.3%). However, further studies are needed to better elucidate the epidemiology, natural history, clinical relevance, and optimal treatment of drug-associated factor VIII autoantibodies.

Valproate-associated coagulopathies are frequent and variable in children.

PURPOSE: Valproic acid (VPA) is an antiepileptic drug (AED) commonly used for generalized and focal epilepsies. The clinical relevance of coagulopathies, known as side effects of VPA therapy, especially thrombocytopenia, von Willebrand disease, and a decrease of factor XIII, is still unclear. METHODS: In our institute, we noticed a high incidence of clinically relevant coagulation problems related to VPA in eight patients within 1 year only and a further seven children with significant coagulopathy were identified in the context of planned surgery. RESULTS: We provide an overview of these patients and all six VPA-induced coagulopathies. CONCLUSIONS: At this time, it cannot be recommended to control all hemostatic parameters in every patient. Whenever an increased bleeding tendency is observed, or before surgical procedures, a platelet count, thrombelastography, prothrombin time, activated partial thromboplastin time, TT, fibrinogen, von Willebrand factor, and factor XIII should be examined. With 385 VPA-treated patients per year and 15 cases of coagulation disorders in this period, we estimate the incidence of coagulation disorders related to VPA in children to be nearly 4%.