Acquired Factor VIII Inhibitors: A Case Study.

The physiology of hemostasis is one of high complexity that involves the initiation, amplification, and propagation of the many moving parts of the hemostatic system and its regulatory mechanisms. It is imperative that clinical laboratory professionals have a strong understanding of the many intricacies of the physiology of coagulation and its in vitro testing. An elongated activated partial thromboplastin time can have several causes, and the correct cause must be elucidated in a timely manner for proper treatment. A mixing study with normal pooled plasma should be performed to evaluate for the presence of an inhibitor vs factor deficiency. Factor inhibitors, specifically factor VIII in this case study, should be titered so that the clinician can decide which treatment may work best for the patient. Continued monitoring of factor levels and inhibitor titers should be conducted to follow the resolution or progression of inhibitor presence.

Prolonged Elevations of Factor VIII and von Willebrand Factor Antigen After Multisystem Inflammatory Syndrome in Children.

Multisystem Inflammatory Syndrome in Children (MIS-C) is a late systemic inflammatory response to a recent mild or asymptomatic coronavirus disease of 2019 infection. The pathophysiology is incompletely understood but it often features significant coagulopathy along with cardiac and endothelial dysfunction. Endothelial inflammation has been primarily described in acute coronavirus disease of 2019 infection, with less characterization in MIS-C. Here we describe novel findings of nearly universal severe and prolonged factor VIII (FVIII) and von Willebrand factor antigen elevations in an institutional cohort of patients with MIS-C ages younger than or 21 years old (N=31). All patients had elevated acute phase reactants and D-dimer at presentation and met published criteria for MIS-C. FVIII was high at presentation in 97% of patients but continued to rise during the ensuing weeks of treatment to a mean 429%, peaking on median day 17 of illness as an outpatient. FVIII levels were >600% in multiple patients. von Willebrand factor antigen was measured less frequently but showed similar trends. These escalations occurred amidst resolving cardiac dysfunction and acute phase reactant normalization and despite patients receiving multimodal anti-inflammatory treatments and aspirin and enoxaparin thromboprophylaxis. No thrombotic events occurred. Endothelial dysfunction represented by very elevated FVIII levels may persist longer than other acute phase reactants may reflect.

Coagulation Profile in COVID-19 Patients and its Relation to Disease Severity and Overall Survival: A Single-Center Study.

Objectives: This study aims to investigate hemostatic changes in patients with coronavirus disease (COVID-19) and their relationship to disease severity and survival. Methods: This study included 284 patients with COVID-19 who attended the Security Forces Hospital, Makkah, Saudi Arabia between October 2020 and March 2021, and retrospectively reviewed their demographic, radiological, and laboratory findings. The coagulation profile was assayed at the time of diagnosis for platelet counts using an automated hematology analyzer; Sysmex XN2000 while international normalized ratio (INR), activated partial thromboplastin time (aPTT), fibrinogen, D-dimer, factor VIII, ristocetin cofactor (RiCoF), and von Willebrand factor antigen (VWF-Ag) were measured by Stago kits on a Stago automated coagulation analyzer (STA Compact Max®). Results: In this study, 32.3% of the cases had severe disease, while 8.8% of the cases died. D-dimer, factor VIII, and RiCoF were the only independent predictors of disease severity, with factor VIII and RiCoF having significantly higher areas under the curve (AUCs) than D-dimer (all p < 0.001). Furthermore, age, aPTT, and factor VIII were associated with an increased risk of mortality in multivariate Cox regression analysis, with factor VIII having a higher AUC of 0.98 than aPTT with an optimal cut-off value of >314 IU/dl in predicting mortality. Cases with factor VIII levels >314 IU/dl, compared to those with factor VIII levels <314 IU/dl, were associated with a significantly shorter mean overall survival time (20.08 vs. 31.35 days, p < 0.001), a lower survival rate (30.3% vs. 99.2%, p < 0.001), and a 16.62-fold increased mortality risk. Conclusion: RiCoF is a novel predictor of disease severity in COVID-19, while factor VIII is confirmed as a predictor of severity and mortality in COVID-19 patients and is associated with lower overall survival and increased mortality risk.

[Acquired hemophilia A that developed after BNT162b2 mRNA COVID-19 vaccination and worsened following re-vaccination].

An 86-year-old Japanese male patient visited a nearby hospital with painful swelling in his left upper and lower limbs 35 days after the second dose of the BNT162b2 mRNA coronavirus disease-2019 (COVID-19) vaccine. He was referred to our hematological department due to a prolonged activated partial thromboplastin time and was urgently admitted. He was diagnosed with acquired hemophilia A (AHA) based on factor VIII (FVIII) activity of 1.7%, FVIII inhibitor of 152.3 BU/ml, and FVIII-binding antibodies detected by enzyme-linked immunosorbent assay. Immunosuppressive therapy with prednisolone (PSL) at 0.5 mg/kg/day was started owing to the risk of infection due to old age and poor activities of daily living. Hemostasis treatment with bypass hemostatic preparations (rFVIIa preparation, FVIIa/FX) was administered for each bleeding event, such as intramuscular and knee joint bleeding, resulting in good hemostatic effects. Coagulative complete remission was achieved on day 69 with PSL treatment; however, FVIII activity decreased with PSL tapering. AHA relapse with rectus abdominis muscle hematoma was observed after the third vaccination. This is the first Japanese report of AHA after COVID-19 vaccination and the world's first case, in which the presence of anti-FVIII-binding antibodies were observed.

Emicizumab: a novel drug in hemophilia A prophylaxis - a narrative review.

INTRODUCTION: Hemophilia A is a genetically conditioned disease leading to hemostatic disorders due to factor VIII (FVIII) deficiency. The treatment of hemophilia has evolved throughout the past years and has significantly changed. One of the newest drugs for prophylactic treatment is the humanized bispecific IgG antibody - emicizumab, which binds with factor IXa and factor X, bridging those factors and thus mimicking the activity of factor VIII. AREAS COVERED: The literature search was done via the PubMed database, with the emphasis on clinical trials and case reports, describing the off-label emicizumab use. This review presents an extensive summary and considers the advantages and disadvantages (side-effects) of emicizumab, describing additional clinical situations, where emicizumab has been successfully used. In our review, we cover information about the mechanisms of action, indications, and efficacy and discuss some chosen case reports about off-label emicizumab use. EXPERT OPINION: Its convenient administration method (subcutaneous) and frequency of injections (from once a week to once a month) makes it a more comfortable treatment, limiting injection-site reactions, hospital stays, costs of prophylaxis, and significantly increasing patients' quality of life. Adverse effects are scarce and rarely serious - the most common ones are reactions at the injection-site and upper respiratory tract infections.

Complementary Sets of Autoantibodies Induced by SARS-CoV-2, Adenovirus and Bacterial Antigens Cross-React with Human Blood Protein Antigens in COVID-19 Coagulopathies.

COVID-19 patients often develop coagulopathies including microclotting, thrombotic strokes or thrombocytopenia. Autoantibodies are present against blood-related proteins including cardiolipin (CL), serum albumin (SA), platelet factor 4 (PF4), beta 2 glycoprotein 1 (ß2GPI), phosphodiesterases (PDE), and coagulation factors such as Factor II, IX, X and von Willebrand factor (vWF). Different combinations of autoantibodies associate with different coagulopathies. Previous research revealed similarities between proteins with blood clotting functions and SARS-CoV-2 proteins, adenovirus, and bacterial proteins associated with moderate-to-severe COVID-19 infections. This study investigated whether polyclonal antibodies (mainly goat and rabbit) against these viruses and bacteria recognize human blood-related proteins. Antibodies against SARS-CoV-2 and adenovirus recognized vWF, PDE and PF4 and SARS-CoV-2 antibodies also recognized additional antigens. Most bacterial antibodies tested (group A streptococci [GAS], staphylococci, Escherichia coli [E. coli], Klebsiella pneumoniae, Clostridia, and Mycobacterium tuberculosis) cross-reacted with CL and PF4. while GAS antibodies also bound to F2, Factor VIII, Factor IX, and vWF, and E. coli antibodies to PDE. All cross-reactive interactions involved antibody-antigen binding constants smaller than 100 nM. Since most COVID-19 coagulopathy patients display autoantibodies against vWF, PDE and PF4 along with CL, combinations of viral and bacterial infections appear to be necessary to initiate their autoimmune coagulopathies.

Challenging treatment for refractory acquired haemophilia A complicated with severe severe acute respiratory coronavirus 2 infection.

Immunosuppressive treatment and bypassing agents are used to treat acquired haemophilia A (AHA). On the other hand, COVID-19 infection induces a hypercoagulable state. Managing bleeding, risk of thrombosis, bypassing agents, active infection and immunosuppressive treatment can be challenging. A 72-year-old man was diagnosed with acquired hemophilia A. He received steroids, rituximab and recombinant activated factor VII (rFVIIa). He developed severe SARS-CoV-2 infection. Due to thrombotic risk, he received low-molecular-weight heparin (LMWH) and developed an iliopsoas hematoma. Because of the risk of thrombosis, treatment with recombinant porcine FVIII (rpFVIII) was requested. Tocilizumab was administered for treatment of SARS-CoV-2 infection and unexpected improvement of FVIII levels was noted. Concluding, rpFVIII treatment was well tolerated and effective, easy to monitor and to administer. Tocilizumab may play a role as immunosuppressive treatment for AHA. The role of LMWH remains to be established in patients with coagulopathies.

The Vascular Endothelium and Coagulation: Homeostasis, Disease, and Treatment, with a Focus on the Von Willebrand Factor and Factors VIII and V.

The vascular endothelium has several important functions, including hemostasis. The homeostasis of hemostasis is based on a fine balance between procoagulant and anticoagulant proteins and between fibrinolytic and antifibrinolytic ones. Coagulopathies are characterized by a mutation-induced alteration of the function of certain coagulation factors or by a disturbed balance between the mechanisms responsible for regulating coagulation. Homeostatic therapies consist in replacement and nonreplacement treatments or in the administration of antifibrinolytic agents. Rebalancing products reestablish hemostasis by inhibiting natural anticoagulant pathways. These agents include monoclonal antibodies, such as concizumab and marstacimab, which target the tissue factor pathway inhibitor; interfering RNA therapies, such as fitusiran, which targets antithrombin III; and protease inhibitors, such as serpinPC, which targets active protein C. In cases of thrombophilia (deficiency of protein C, protein S, or factor V Leiden), treatment may consist in direct oral anticoagulants, replacement therapy (plasma or recombinant ADAMTS13) in cases of a congenital deficiency of ADAMTS13, or immunomodulators (prednisone) if the thrombophilia is autoimmune. Monoclonal-antibody-based anti-vWF immunotherapy (caplacizumab) is used in the context of severe thrombophilia, regardless of the cause of the disorder. In cases of disseminated intravascular coagulation, the treatment of choice consists in administration of antifibrinolytics, all-trans-retinoic acid, and recombinant soluble human thrombomodulin.

Prognostic value of von Willebrand factor and ADAMTS13 in patients with COVID-19: A systematic review and meta-analysis.

BACKGROUND: Endotheliopathy and coagulopathy appear to be the main causes for critical illness and death in patients with coronavirus disease 2019 (COVID-19). The adhesive ligand von Willebrand factor (VWF) has been involved in immunothrombosis responding to endothelial injury. Here, we reviewed the current literature and performed meta-analyses on the relationship between both VWF and its cleaving protease ADAMTS13 (a disintegrin and metalloproteinase with thrombospondin type 1 motif, member 13) with the prognosis of COVID-19. METHODS: We searched MEDLINE, Cochrane Library, Web of Science, and EMBASE databases from inception to 4 March 2022 for studies analyzing the relationship between VWF-related variables and composite clinical outcomes of patients with COVID-19. The VWF-related variables analyzed included VWF antigen (VWF:Ag), VWF ristocetin cofactor (VWF:Rco), ADAMTS13 activity (ADAMTS13:Ac), the ratio of VWF:Ag to ADAMTS13:Ac, and coagulation factor VIII (FVIII). The unfavorable outcomes were defined as mortality, intensive care unit (ICU) admission, and severe disease course. We used random or fixed effects models to create summary estimates of risk. Risk of bias was assessed based on the principle of the Newcastle-Ottawa Scale. RESULTS: A total of 3764 patients from 40 studies were included. The estimated pooled means indicated increased plasma levels of VWF:Ag, VWF:Rco, and VWF:Ag/ADAMTS13:Ac ratio, and decreased plasma levels of ADAMTS13:Ac in COVID-19 patients with unfavorable outcomes when compared to those with favorable outcomes (composite outcomes or subgroup analyses of non-survivor versus survivor, ICU versus non-ICU, and severe versus non-severe). In addition, FVIII were higher in COVID-19 patients with unfavorable outcomes. Subgroup analyses indicated that FVIII was higher in patients admitting to ICU, while there was no significant difference between non-survivors and survivors. CONCLUSIONS: The imbalance of the VWF-ADAMTS13 axis (massive quantitative and qualitative increases of VWF with relative deficiency of ADAMTS13) is associated with poor prognosis of patients with COVID-19.

A case of acquired hemophilia A and bullous pemphigoid following SARS-CoV-2 mRNA vaccination.

Acquired hemophilia is a rare disease resulting from autoantibodies against endogenous factor VIII (FVIII), which associates with bleeding and a high mortality rate. The pathophysiology is still unclear. Recent studies suggest genetic and environmental factors trigger the breakdown of immune tolerance. We report a 77-year-old Taiwanese man presented with multiple ecchymoses and some hemorrhagic blisters three weeks after SARS-CoV-2 mRNA (Moderna) vaccination. Isolated activated partial thromboplastin time (aPTT) prolongation was found. Acquired hemophilia A (AHA) was confirmed by low factor VIII (FVIII) activity and high titer of FVIII inhibitor. The pathohistology of skin biopsy further supported the concomitant diagnosis of bullous pemphigoid. To date, 6 cases of acquired hemophilia A following SARS-CoV-2 mRNA vaccination were reported worldwide. We reviewed and summarized the characteristics of these cases. We also discussed the rare finding of concomitant acquired hemophilia A and bullous pemphigoid. Bullous pemphigoid results from autoantibody against epithelial basement membrane zone of skin. In this article, we proposed possibility of SARS-CoV-2 mRNA vaccine associated autoimmunity against FVIII and epithelial basement membrane zone.

Multisystem inflammatory syndrome in a neonate with severe hemophilia - a diagnostic challenge in COVID times: a case report.

BACKGROUND: Multisystem Inflammatory Syndrome in Neonates (MIS-N) can occur following antenatal COVID- 19 infection in the mother. Here we report a rare case of a neonate with Hemophilia A and MIS-N. CASE PRESENTATION: A 2-day-old baby presented with an intramuscular hematoma, neonatal seizures, and isolated activated partial thromboplastin time (APTT) prolongation. The neurosonogram showed a subdural hematoma. A diagnosis of Hemophilia A was made and was confirmed by factor 8 assay and genetic analysis. Supportive measures and Factor 8 replacement was initiated. A rising trend of inflammatory markers and an ongoing need for mechanical ventilation were noted. As there was a history of COVID-19 in the mother in the third trimester, MIS-N was diagnosed. The baby was treated with intravenous immunoglobulin (IVIG) and steroids, and there was an improvement in the clinical and laboratory markers. However, the baby developed seizures on day 16. There was an increase in the subdural hemorrhage and a further rise in inflammatory markers. A craniostomy and hematoma evacuation was done and the baby improved. CONCLUSION: The concurrent occurrence of hemophilia A with intracranial bleed, and MIS-N in a neonate is a diagnostic challenge. It is important to have a high index of suspicion to ensure timely diagnosis and treatment of MIS-N in this pandemic era.

Hypercoagulability, endotheliopathy, and inflammation approximating 1 year after recovery: Assessing the long-term outcomes in COVID-19 patients.

Sustained hypercoagulability and endotheliopathy are present in convalescent COVID-19 patients for up to 4 months from recovery. The hemostatic, endothelial, and inflammatory profiles of 39 recovered COVID-19 patients were evaluated up to 16 months after recovery from COVID-19. These values were compared with a control group of healthy volunteers (n = 124). 39 patients (71.8% males, median age 43 years) were reviewed at a mean of 12.7 ± 3.6 months following recovery. One patient without cardiovascular risk factors had post COVID-19 acute ischaemic limb. Elevated D-dimer and Factor VIII levels above normal ranges were noted in 17.9% (7/39) and 48.7% (19/39) of patients respectively, with a higher median D-dimer 0.34 FEU µg/mL (IQR 0.28, 0.46) (p < .001) and Factor VIII 150% (IQR 171, 203) (p = .004), versus controls. Thrombin generation (Thromboscreen) showed a higher median endogenous thrombin potential (ETP) of 1352 nM*min (IQR 1152, 1490) (p = .002) and a higher median peak height of 221.4 nM (IQR 170.2, 280.4) (p = 0.01) and delayed lag time 2.4 min (1.42-2.97) (p = 0.0002) versus controls. Raised vWF:Ag and ICAM-1 levels were observed in 17.9% (7/39) and 7.7% (3/39) of patients respectively, with a higher median VWF:Ag 117% (IQR 86, 154) (p = 0.02) and ICAM-1 54.1 ng/mL (IQR 43.8, 64.1) (p = .004) than controls. IL-6 was noted to be raised in 35.9% (14/39) of patients, with a higher median IL-6 of 1.5 pg/mL (IQR 0.6, 3.0) (p = 0.004) versus controls. Subgroup analysis stratifying patients by COVID-19 severity and COVID-19 vaccination preceding SARS-CoV-2 infection did not show statistically significant differences. Hypercoagulability, endothelial dysfunction, and inflammation are still detectable in some patients approximately 1 year after recovery from COVID-19.

Safety of intramuscular COVID-19 vaccination in patients with haemophilia.

BACKGROUND: Guidelines recommend that patients with haemophilia should preferably receive vaccination subcutaneously. COVID-19 and other vaccines, however, are only licenced for intramuscular application. AIMS: To assess the safety of intramuscular COVID-19 vaccination in patients living with haemophilia. METHODS: Part A of this prospective observational study enrolled consecutive patients with haemophilia A (HA) and B (HB) of all ages and severities and assessed injection site bleeding and other complications within 30 days of vaccination. Part B enrolled patients providing informed consent for detailed data collection including medication and prophylaxis around the time of vaccination. Logistic regression was performed to assess potential risk factors for bleeding. RESULTS: Four hundred and sixty-one patients were enrolled into part A. The primary endpoint injection site bleeding occurred in seven patients (1.5%, 95% confidence interval .7-3.1%). Comprehensive analysis of 214 patients (404 vaccinations, part B) revealed that 97% of patients with severe haemophilia had prophylaxis before vaccination, either as part of their routine prophylaxis or using additional doses. 56% and 30% of patients with moderate and mild haemophilia, respectively, received prophylaxis before vaccination. Among the seven bleeds recorded, three occurred when intramuscular vaccination was done without prophylaxis (odds ratio 12). CONCLUSIONS: This is the first prospective study reporting on the safety of intramuscular vaccination in haemophilia. The rate of injection site bleeding was low in mild haemophilia, and in moderate and severe haemophilia if patients received factor prophylaxis.

Morphological and Immunopathological Aspects of Lingual Tissues in COVID-19.

COVID-19, a recently emerged disease caused by SARS-CoV-2 infection, can present with different degrees of severity and a large variety of signs and symptoms. The oral manifestations of COVID-19 often involve the tongue, with loss of taste being one of the most common symptoms of the disease. This study aimed to detect SARS-CoV-2 RNA and assess possible morphological and immunopathological alterations in the lingual tissue of patients who died with a history of SARS-CoV-2 infection. Sixteen cadavers from 8 SARS-CoV-2 positive (COVID-19+) and 8 negative (COVID-19-) subjects provided 16 tongues, that were biopsied. Samples underwent molecular analysis through Real-Time RT-PCR for the detection of SARS-CoV-2 RNA. Lingual papillae were harvested and processed for histological analysis and for immunohistochemical evaluation for ACE2, IFN-γ and factor VIII. Real-Time RT-PCR revealed the presence of SARS-CoV-2 RNA in filiform, foliate, and circumvallate papillae in 6 out of 8 COVID-19+ subjects while all COVID-19- samples resulted negative. Histology showed a severe inflammation of COVID-19+ papillae with destruction of the taste buds. ACE2 and IFN-γ resulted downregulated in COVID-19+ and no differences were evidenced for factor VIII between the two groups. The virus was detectable in most COVID-19+ tongues. An inflammatory damage to the lingual papillae, putatively mediated by ACE2 and IFN-γ in tongues from COVID-19+ cadavers, was observed. Further investigations are needed to confirm these findings and deepen the association between taste disorders and inflammation in SARS-CoV-2 infection.