Acquired Haemophilia A: An Intriguing Disease

Inhibitor eradication and treatment for acquired hemophilia A

INTRODUCTION

Acquired hemophilia A (AHA) is a rare hemorrhagic autoimmune disorder characterized by autoantibodies against coagulation factor VIII (FVIII). In approximately half of the cases AHA does not recognize any cause (idiopathic form), while in the other cases it may be triggered by autoimmune disorders, cancers, drugs, infections, or pregnancy. Besides treating the underlying disorder, specific AHA treatment includes management of bleeding, if necessary, and inhibitor eradication.

AREAS COVERED

This narrative review summarizes the main epidemiological, clinical, laboratory, and therapeutic characteristics of AHA. In particular, it is focused on the current therapeutic options for the inhibitor eradication, also showing the latest findings on the innovative therapies. A literature search strategy was performed, without temporal limits, through Medline and PubMed electronic databases.

EXPERT OPINION

Various first-line and second-line immunosuppressive agents are currently available for the management of AHA. Among the latter, the anti-CD20 monoclonal antibody rituximab has been the object of intense research during the last years from investigators as innovative promising eradicating therapy for AHA. Preliminary data from the studies support the use of this drug as a first-line option for newly diagnosed AHA cases.

Innovative Therapies for Acquired Hemophilia A

Acquired hemophilia A (AHA) is a rare autoimmune bleeding disorder which can be life-threatening. AHA is due to autoantibodies against coagulation factor VIII. Disease onset may be idiopathic (approximately half of the cases) or triggered by autoimmune disorders, cancers, drugs, infections, or pregnancy. Besides treating the underlying disorder, specific AHA treatments include management of bleeding and inhibitor eradication. Various first-line and second-line hemostatic and immunosuppressive agents are currently available for the management of AHA. Recently, the hemostatic drug emicizumab and the immunosuppressive drug rituximab have been the object of intense research from investigators as innovative promising therapies for AHA. This narrative review will be focused on the current status of the clinical use of these two off-label therapeutic agents in AHA.

Systemic lupus erythematosus with acquired hemophilia A: A case report and literature review

Systemic lupus erythematosus (SLE) complicated with acquired hemophilia A (AHA) is a rare condition with frequently delayed diagnosis and a high mortality rate, so it is necessary to strengthen the understanding of this disease. In this study, the characteristics and treatment in 1 case of SLE complicated by AHA is reported and analyzed, and a literature review is conducted. The patient was a 29-year-old young female with a 10-year history of SLE, the main clinical manifestation was severe abdominal bleeding. Laboratory tests revealed that the activated partial thromboplastin time (APTT) was notably prolonged (118.20 s), and the coagulation factor VIII activity (FVIII꞉C) was extremely decreased (0.20%) with high-titer of factor VIII (FVIII) inhibitor (31.2 BU/mL). After treating with high-dose glucocorticoid, immunoglobulin, cyclophosphamide, rituximab, blood transfusion, and intravenous infusion of human coagulation FVIII, the coagulation function and coagulation FVIII꞉C were improved, and FVIII inhibitor was negative without serious adverse reactions. During the next 5-year follow-up, the patient's condition was stable and no bleeding occurred. In the case of coagulation dysfunction in SLE, especially with isolated APTT prolongation, AHA should be screened. When the therapeutic effects of glucocorticoid combined with immunosuppressants are not desirable, rituximab could be introduced.

A Case Report of Idiopathic Acquired Hemophilia Type A

Acquired hemophilia A (AHA) is a rare hemorrhagic coagulopathy caused by the presence of autoantibodies that inhibit the activity of factor VIII (FVIII). Its diagnosis requires a high index of suspicion. It should be suspected in the presence of extensive hematomas or intense mucosal bleeding in patients with no history of previous trauma or hemorrhagic symptoms. We present two clinical cases of AHA, with different presentations and therapeutic management based on immunosuppression and hemostatic control through bypass agents such as activated recombinant FVII (rFVIIa; Novoseven®) and activated prothrombin complex concentrate (aPCC; Feiba®). The first case was an idiopathic AHA that presented with extensive subcutaneous hematomas with inhibitor titer >40 Bethesda units/ml (BU/mL), prolonged activated partial thromboplastin time (aPTT), and FVIII of 0.8%. In contrast, the second case involved a patient with a history of autoimmune disease, who presented with epistaxis and inhibitor titer of 10.8 BU/ml and FVIII of 5.3%.

Acquired Hemophilia A: An Update on the Etiopathogenesis, Diagnosis, and Treatment

Acquired haemophilia A (AHA) is a rare bleeding disorder caused by inhibitory autoantibodies against coagulation factor VIII (FVIII). AHA is a disease that most commonly affects the elderly but has also been observed in children and in the postpartum period. AHA is idiopathic in 50% of cases and is associated with autoimmune diseases, malignancies, and infections in the remaining 50%. Recently, cases of association between AHA, COVID-19 vaccination, and infection have been reported in the literature. For diagnoses, determining FVIII levels is crucial to distinguish the different causes of aPTT prolongation. Treatment of AHA is based on bypassing agents (recombinant factor VIIa, activated prothrombin complex concentrate) and porcine FVIII to control the bleeding and immunosuppressive therapy (corticosteroids, rituximab, cyclophosphamide) to suppress autoantibody production. It is important to start a prophylactic regimen to prevent further bleeding episodes until the inhibitor is negative. Recently, the series of cases reported in the literature suggest that emicizumab may provide effective and safe haemorrhage prophylaxis in the outpatient setting.

Acquired Hemophilia A: A Retrospective Multicenter Analysis of 42 Patients

INTRODUCTION

Immunosuppressive therapy (IST) for acquired hemophilia A (AHA) results in remission within days to months in 60% to 80% of patients. However, little is known regarding the predictors of response.

AIM

This study aimed to identify the factors that influence response to treatment.

METHODS

The data of 42 patients with AHA from three hospitals were retrospectively analyzed.

RESULTS

All 42 AHA patients received IST; complete treatment data were available for 34 patients. The response rate was 60% among the 5/34 (14.7%) patients who received steroids alone, 70.8% among the 24/34 (70.6%) patients who received steroids plus cyclophosphamide, and 80% among the 5/34 (14.7%) patients who received steroids plus cyclophosphamide and rituximab. Overall, 29/34 (85.3%) patients achieved CR; 4/34 (13.8%) of them relapsed after a median time of 410 (21-1279) days. Adverse events occurred in 14/34 (41.2%) patients: 13/34 (38.2%) had infections and 1/34 (2.9%) developed pancytopenia. In univariate and multivariate Cox regression analyses, FVIII inhibitor titer ≥20 BU/mL was the only significant prognostic factor affecting time to CR. No variable had significant effect on OS.

CONCLUSION

FVIII inhibitory antibody titer ≥20 BU/mL appears to be an important predictor of time to complete response in patients with acquired hemophilia A treated with immunosuppressive therapy.

Single centre experience on Acquired Haemophilia A patients: Diagnosis, clinical management and analysis of factors predictive of response and outcome

BACKGROUND

Acquired Haemophilia A (AHA) patients show a high response rate to immunosuppressive therapy (IST) but few information about predictors of response and outcome are reported.

AIMS

We describe a large single-centre AHA cohort, investigating prognostic variables for the 'best response' (BR), time to BR (TTBR) and overall survival (OS).

METHODS

A total of 61 patients were included, collecting data from clinical charts.

RESULTS

A progressive increase in diagnoses, from 1978 to 2019, was observed. Fifty/56 patients (89%) underwent haemostatic therapy (rFVIIa 46%, aPCC 34%) with no significant differences in the response (rFVIIa 92.3% vs aPCC 100%) and no thromboembolic events. Sixty/61 patients underwent first-line IST with an initial response rate of 58.4%. The 12-months OS was 85%, the bleeding associated mortality rate 3% (2/61). The response rates at last observation were: CR 64%, PR 8%. We evaluated the influence of age, gender, associated conditions, IST, haemoglobin levels, FVIII:C, inhibitor titre on BR, TTBR and OS: post-partum AHA achieved the BR after a longer time than AHA related to other aetiologies or idiopathic (p = .05); in univariate analysis female sex (p = .03) and the achievement of BR (p = .001) had a positive impact on the OS while AHA secondary to neoplasms showed a shorter survival (p = .04); only the BR achievement remained significant in multivariate analysis (p = .02).

CONCLUSIONS

Our data on response and survival confirmed those from the main registries. Post-partum AHA and BR achievement were significantly associated to a longer TTBR and a longer OS, respectively. Other predictors of outcome deserve to be explored in prospective studies.

The Possible Non-Mutational Causes of FVIII Deficiency: Non-Coding RNAs and Acquired Hemophilia A

Hemophilia type A (HA) is the most common type of blood coagulation disorder. While the vast majority of cases are inherited and caused by mutations in the F8 gene, recent data raises new questions regarding the non-heritability of this disease, as well as how other molecular mechanisms might lead to the development of HA or increase the severity of the disease. Some data suggest that miRNAs may affect the severity of HA, but for some patients, miRNA-based interference might cause HA, in the absence of an F8 mutation. A mechanism in HA installation that is also worth investigating and which could be identified in the future is the epigenetic silencing of the F8 gene that might be only temporarily. Acquired HA is increasingly reported and as more cases are identified, the description of the disease might become challenging, as cases without FVIII autoantibodies might be identified.