Assessment of acquired hemophilia patient demographics in the United States: the Hemostasis and Thrombosis Research Society Registry

Lipopolysaccharide-binding protein functions as factor VIII inhibitor in bullous pemphigoid associated with acquired hemophilia A

Bullous pemphigoid (BP) represents an autoimmune blistering disorder that may coexist with acquired hemophilia A (AHA), a rare autoimmune condition arising from the formation of circulating autoantibodies directed against factor VIII (FVIII). The underlying pathomechanisms of BP-AHA remain elusive. This study conducted a retrospective analysis of data from 196 BP patients admitted to our hospital. We have collected serum samples from a recently admitted BP-AHA patient and healthy controls to isolate, screen and identify the potential FVIII inhibitors. The expression and function of lipopolysaccharide-binding protein (LBP) in BP-AHA were further validated by a series of biochemical experiments. The retrospective analysis showed that the activated partial thromboplastin time (APTT) values of seven patients exceeded 33.8 s (normal value) in 196 BP patients. FVIII: C (%) and FVIII inhibitors in the plasma of partial prolonged-APTT patients were significantly altered compared with control group or non-prolonged-APTT group. LBP was identified as a potential inhibitory protein of FVIII. Consistently, a notable alteration in LBP expression was observed in the plasma of BP patients with prolonged-APTT. Moreover, the amount of LBP bound to FVIII in the BP-AHA patient was notably higher than that in control group, which was also markedly reversed after treatment. In vitro experiments finally confirmed that exogenous LBP directly bound to FVIII and significantly inhibited FVIII activity. In conclusion, the incidence of AHA in BP patients may be substantially underestimated, which needs more vigilance towards indicators such as APTT, LBP, and FVIII. LBP emerges as an inhibitory protein of FVIII, indicating the potential involvement in the progression of BP-AHA.

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.

[Acquired haemophilia: Update in 2024]

Acquired hemophilia A (AHA) is a rare autoimmune disorder due to autoantibodies against factor VIII, with a high mortality risk. It should be suspected in subjects with abnormal bleedings, especially subcutaneous bleed associated with prolonged activated partial thromboplastin time (aPTT). AHA is often idiopathic but is associated with autoimmune diseases, malignancies, pregnancy and postpartum period or drugs. Treatment is based on haemostatic agents as by-passants agents such as factor VIIa and activated prothrombine concentrate complex or recombinant porcine factor VIII for severe bleeding. Eradication of inhibitor should be established as soon as the diagnosis is confirmed with steroid alone often associated with cytotoxic agents or rituximab, depending on FVIII activity and inhibitor titer. The purpose of this review is to summarize the epidemiology, etiopathogenesis, diagnosis, treatment of AHA and discuss current recommendations.

Comorbidity and adverse events in acquired hemophilia A: data from the GTH-AHA-EMI study

Background

Persons with acquired hemophilia A are often older and suffer from comorbidity or frailty. Little is known about the impact on clinically relevant outcomes of acquired hemophilia A.

Objectives

To assess the relevance of age, physical performance status, comorbidity, and concomitant medication on the risk of bleeding and other outcomes.

Methods

Post hoc analysis of data from the GTH-AHA-EMI study that used emicizumab for bleed protection and withheld immunosuppressive treatment during the early phase of management. Primary endpoint was the rate of clinically relevant new bleeding (CRNB) during the first 12 weeks of emicizumab prophylaxis.

Results

Forty-seven patients were enrolled. Median age was 76 years; performance status (World Health Organization performance status [WHO-PS]) was 3 or worse in 41%; Charlson comorbidity index (CCI) was 5 or higher in 63%; antithrombotic drugs were reported in 34%. Rate of CRNB during 12 weeks of emicizumab prophylaxis was similar across subgroups of age, sex, WHO-PS, CCI, baseline factor VIII activity, and inhibitor titer. Patients with CRNB during the study had more severe anemia already at baseline. However, persistent severe anemia in week 4 was not related to risk of bleeding beyond this time. CRNB was associated with injury from falling in 7 of 14 patients. Adverse events grade 3 or higher were not related to baseline CCI or age but were more frequent in patients with poor WHO-PS.

Conclusion

Emicizumab provided bleed protection regardless of age and comorbidity. Clinical baseline characteristics did not predict breakthrough bleeding under emicizumab. Poor WHO-PS at baseline was associated with severe adverse events during the study.

Efficacy and safety of recombinant porcine factor VIII in Japanese patients with acquired hemophilia A

Acquired hemophilia A (AHA) is a rare bleeding disorder caused by autoantibodies inhibiting human factor VIII (hFVIII). This phase II/III open-label study evaluated the safety and efficacy of recombinant porcine factor VIII (rpFVIII, susoctocog alfa) in adults with AHA and severe bleeding episodes in Japan (NCT04580407). The initial rpFVIII dose was 200 U/kg, with subsequent doses based on clinical measures including plasma FVIII activity. The primary efficacy endpoint was the proportion of severe bleeding episodes with a positive response to rpFVIII therapy 24 h after treatment initiation. Five patients were eligible for, and completed, rpFVIII treatment (age group: 60s-80s; median hFVIII inhibitor: 52 BU/mL; porcine FVIII [pFVIII] inhibitor: 3/5 patients). The median (range) total dose/patient was 548.4 (198-1803) U/kg with a median 3.0 infusions/patient. All patients responded positively to rpFVIII therapy at 24 h regardless of baseline pFVIII inhibitor status. rpFVIII treatment was well tolerated with no adverse events of special interest such as thromboembolic events or de novo pFVIII inhibitors. This study supports the use of rpFVIII as a novel therapy in the clinical management of patients with AHA in Japan. rpFVIII was approved for treating bleeding episodes in adults with AHA in Japan in 2024.

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.

Acquired hemophilia A: a single-center study of 165 patients

Background

Acquired hemophilia A (AHA) is a rare hemorrhagic disorder caused by factor (F)VIII inhibitors. The diagnosis and management of AHA remains challenging because of its rarity and heterogeneity.

Objectives

To analyze the characteristics of AHA to enhance our understanding of this disease and identify effective treatment strategies. To analyze the characteristics of AHA to enhance our understanding of this disease and identify effective treatment strategies.

Methods

Clinical features of 165 patients with AHA from a single center between July 1997 and December 2021 were retrospectively analyzed.

Results

The median age of patients at diagnosis was 45 years. The median time to diagnosis was 30 days. All 165 patients experienced bleeding, with a median bleeding score (BS) of 4 (range, 2-12). Hemostatic therapy was administered to 129 (78.2%) patients. Bleeding control was achieved in 80.0% of patients who received prothrombin complex concentrate and in 92.3% of patients who were treated with recombinant activated FVII. Of the 163 patients who received immunosuppressive therapy, 80 (49.1%) received rituximab-based therapy with a 93.3% complete remission (CR) rate, 50 (30.7%) received steroids plus cyclophosphamide with an 85.0% CR rate, and 22 (13.5%) received steroids alone with an 82.4% CR rate. Six cases relapsed after a median duration of 330 days. Immunosuppressive therapy-related adverse events were reported in 17 patients. Seven deaths were recorded. FVIII inhibitor titer of ≥15 BU/mL and BS of ≥6 were identified as significantly poor prognostic factors for CR.

Conclusion

Immunosuppressive therapies yield remarkably high response rates, with a CR rate exceeding 80%; notably, the regimen containing rituximab exhibits a CR rate of approximately 90%. FVIII inhibitor titer of ≥5 BU/mL and BS of ≥6 were poor predictors of CR in patients with AHA.

Key Genes of the Immune System and Predisposition to Acquired Hemophilia A: Evidence from a Spanish Cohort of 49 Patients Using Next-Generation Sequencing

Acquired hemophilia A (AHA) is a rare bleeding disorder caused by the presence of autoantibodies against factor VIII (FVIII). As with other autoimmune diseases, its etiology is complex and its genetic basis is unknown. The aim of this study was to identify the immunogenetic background that predisposes individuals to AHA. HLA and KIR gene clusters, as well as KLRK1, were sequenced using next-generation sequencing in 49 AHA patients. Associations between candidate genes involved in innate and adaptive immune responses and AHA were addressed by comparing the alleles, genotypes, haplotypes, and gene frequencies in the AHA cohort with those in the donors' samples or Spanish population cohort. Two genes of the HLA cluster, as well as rs1049174 in KLRK1, which tags the natural killer (NK) cytotoxic activity haplotype, were found to be linked to AHA. Specifically, A*03:01 (p = 0.024; odds ratio (OR) = 0.26[0.06-0.85]) and DRB1*13:03 (p = 6.8 × 103, OR = 7.56[1.64-51.40]), as well as rs1049174 (p = 0.012), were significantly associated with AHA. In addition, two AHA patients were found to carry one copy each of the low-frequency allele DQB1*03:09 (nallele = 2, 2.04%), which was completely absent in the donors. To the best of our knowledge, this is the first time that the involvement of these specific alleles in the predisposition to AHA has been proposed. Further molecular and functional studies will be needed to unravel their specific contributions. We believe our findings expand the current knowledge on the genetic factors involved in susceptibility to AHA, which will contribute to improving the diagnosis and prognosis of AHA patients.

Acquired haemophilia A: A 15-year population-based review of incidence rate, patient demographics and treatment outcomes

INTRODUCTION

Acquired haemophilia A (AHA) is a rare bleeding disorder characterized by autoantibodies against coagulation factor VIII (FVIII). Estimates of AHA incidence are largely based on registry data, which may be prone to referral bias. Population-based studies can enhance our understanding of the epidemiology, presentation and outcomes of AHA.

METHODS

We conducted a retrospective, population-based cohort study of all AHA diagnosed and treated in Manitoba, Canada over a 15-year period. Using records from the sole provincial reference laboratory, we identified all patients with FVIII inhibitors who did not have congenital haemophilia.  Using a piloted case report form, patient data was ascertained from hospital and bleeding disorder clinic records.

RESULTS

From 2006 to 2021, we identified 34 patients with AHA, corresponding to a population-based incidence rate of AHA of 1.78 cases per million per year. The median age at presentation was 76 years and most cases were idiopathic (79%). Almost all patients (97%) presented with bleeding, of which 58% were considered major bleeds and required haemostatic agents in 67%. Longstanding unexplained bleeding symptoms were commonly reported, suggesting delayed diagnosis. Immunosuppressive therapy (IST) was administered in 88% of patients. Remission was achieved in 79% of patients; median time to remission was 2.1 months. There were two deaths due to bleeding. No deaths due to IST were reported.

CONCLUSION

The population-based incidence of AHA in Manitoba is 1.78 cases/million/year. Bleeding is common and can be life-threatening. AHA outcomes are encouraging with the use of haemostatic agents and IST. Serious treatment-associated morbidity and mortality is uncommon.

Acquired Hemophilia A after SARS-CoV-2 Infection: A Case Report and an Updated Systematic Review

The role of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has been implicated in the pathogenesis of acquired hemophilia A (AHA). The aim of this study is to report our case and to summarize clinical studies on de novo AHA after SARS-CoV-2 infection. We performed a systematic search on the association of SARS-CoV-2 with AHA in four medical databases up to 28 May 2023. Eligible studies should include de novo AHA patients who had SARS-CoV-2 infection before or concomitant with the diagnosis of AHA. Findings were synthesized narratively. In addition, we report the case of a 62-year-old female patient, who presented to our clinic with left flank pain 2 weeks after SARS-CoV-2 infection. Clinical investigations confirmed AHA and imaging studies revealed retroperitoneal bleeding. Her hemostasis was successfully secured with bypassing agents; however, despite immunosuppressive therapy, high inhibitor titer persisted. In the systematic review, we identified only 12 relevant cases with a questionable cause-effect relationship between SARS-CoV-2 infection and AHA. Based on the qualitative analysis of the relevant publications, current clinical evidence is insufficient to support a cause-effect relationship. The analysis of data from ongoing AHA registries can serve further evidence.

Acquired haemophilia A in southern Switzerland from 2013 to 2019: a case series

AIMS OF THE STUDY: Acquired haemophilia A is a rare disease with an annual incidence of 1.48 per million. Based on clinical observations, we suspect a higher incidence in southern Switzerland, and aimed at providing local epidemiological data, and clinical information regarding diagnosis, treatment and outcome in our region. METHODS: All adult patients with acquired haemophilia A treated between 2013 and 2019 in our facility were included in the present retrospective analysis. RESULTS: We treated 11 patients with acquired haemophilia A between 2013 and 2019, resulting in an annual incidence of 4.5 per million (95% confidence interval [CI] 0–9.0). Median delay from first symptoms to diagnosis was 4.5 days, and the median age at diagnosis was 79 years (range 23–87). Possible causative conditions were: pregnancy (n = 1), polyarteritis nodosa (n = 1), myelodysplastic syndrome (n = 1), chronic human immunodeficiency virus (HIV) (n = 1), and HIV postexposure prophylaxis (n = 1). In five patients no underlying or associated condition was identified. Median activated partial thromboplastin time (aPTT)) at baseline was 79 seconds (65–117; ref. value <38 sec), and FVIII:C 2.15% (<1–3.75%). A FVIII:C <1% was present in 4/10 patients. Median FVIII-inhibitor titre was 10.3 BU/ml (2.4–75.0 BU/ml). All patients had bleeding symptoms, 5/10 patients had major bleedings, and 7/10 patients were treated with bypassing agents. All patients received corticosteroids; 7/10 patients received immunosuppressive combination therapy. FVIII levels of ≥50% were achieved after a median of 40 days (8–62). One patient had a severe immunosuppressive therapy-related infection. An 87-years-old woman died for reasons not related to acquired haemophilia A or immunosuppressive therapy. CONCLUSIONS: Acquired haemophilia A is a rare disease, but manageable despite the advanced patient age and comorbidities. Its incidence in Southern Switzerland is higher than previously suspected.

Investigating a Signal of Acquired Hemophilia Associated with COVID-19 Vaccination: A Systematic Case Review

Acquired hemophilia A (AHA), a rare but life-threatening disorder, most commonly occurs in older people and during pregnancy. During the coronavirus disease 2019 (COVID-19) vaccination campaign, an unexpected number of newly diagnosed AHA patients have been identified in clinical practice that were temporally related to COVID-19 vaccination. We present the result of a signal detection analysis aimed at exploring a possible association between COVID-19 immunization and occurrence of AHA. A disproportionality analysis on the World Health Organization (WHO) database was performed to investigate the presence of a signal of risk for AHA associated with COVID-19 vaccines. Reports of AHA associated with any COVID-19 vaccine included in the WHO database were then integrated with those available on the Food and Drug Administration Vaccine Adverse Events Reporting System and those published in the medical literature. The WHO database included 146 reports of AHA. The information component (IC) was significant for the association of AHA with all COVID-19 vaccines (IC025: 1.1) and with the vaccine product BNT162b2 (IC025: 1.6). After duplicate exclusion, 96 unique cases of AHA following COVID-19 vaccines have been reviewed. Median time to diagnosis was 18 days and 40% of cases documented the occurrence after the second dose. Overall, in 57% of the investigated cases, a preexisting condition predisposing to AHA was excluded. About 22% of cases occurred in subjects with age ≤65 years and there was no case associated with pregnancy. Mortality was 11%. Although we cannot exclude that the unexpected frequency of AHA diagnosis can be explained by a detection bias, the signal for COVID-19 vaccine-related AHA is robust and deserves further investigations.

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.

The diagnosis and Management of HIV Associated Acquired Hemophilia A: A Case Series From Durban, South Africa

INTRODUCTION

In acquired hemophilia A (AHA), the body produces auto-antibodies against Factor VIII. Although AHA is rare, with an incidence of 1.5 patients/1 million population/year, there is a strong association with human immunodeficiency virus (HIV) infection. The accurate interpretation of screening coagulation tests is critical to identify patients with AHA, as the mortality rate secondary to bleeding is high.

METHODS

This was a retrospective case series which included all newly diagnosed AHA patients that were referred to Hemophilia care unit at King Edward VIII Hospital, Durban, South Africa from January 2011 to December 2021. The clinical presentation and laboratory results were documented.

RESULTS

Five patients were included in this case series. All patients were females aged between 28 and 64 years of age and they were HIV seropositive. They presented with spontaneous cutaneous and intramuscular bleeding. Four patients were virologically suppressed on anti-retroviral therapy, and no patient had a family history of congenital bleeding diathesis. Laboratory investigations confirmed AHA with high Factor VIII inhibitor titers, which ranged from 41 to 900 Bethesda Units (BU). All patients were managed with bypassing agents and oral corticosteroids. The monitoring of patients after the initiation of treatment was difficult as they all defaulted treatment.

CONCLUSION

In view of the prevalence of HIV in sub-Saharan Africa, there is a possibility that AHA is under-diagnosed in our setting. The clinician and the laboratory have a combined critical role in identifying patients with AHA as the investigation of a prolonged APTT is mandatory. There are challenges in managing AHA patients in a resource-constrained setting.

Emicizumab for the treatment of acquired hemophilia A: Retrospective review of a single-institution experience

INTRODUCTION

Acquired haemophilia A (AHA) is a rare and potentially life-threatening bleeding disorder arising from autoantibodies that inhibit coagulation factor VIII (FVIII). Treatment entails achieving haemostasis with bypassing agents or factor replacement, and eradication of the inhibitor with immunosuppressive therapy (IST). Due to the rarity of AHA, there are few prospective data to guide management.

METHODS

We present a retrospective report of 11 AHA patients treated with emicizumab, a FVIII-mimetic bispecific antibody, administered at 3 mg/kg weekly for 4 weeks in conjunction with rituximab-based immunosuppressive therapy. The chromogenic FVIII inhibitor assay was used to assess for inhibitor eradication.

RESULTS

The median follow-up was 13.9 months. The median number of days of additional haemostatic therapy or red blood cell transfusions after initiating emicizumab was 2 (range 0-15). The median was 0 days (range 0-8) for patients who did not require vascular embolization to achieve haemostasis. Eight patients achieved a complete remission (defined as recovery of FVIII activity to > 50% with a negative inhibitor test in the absence of haemostatic and IST); two patients achieved a partial remission (FVIII activity > 50% but with detectable inhibitor); one patient experienced refractory disease. One patient experienced rebleeding and two patients experienced inhibitor recurrence. No thrombotic, thrombotic microangiopathic or infectious complications occurred.

CONCLUSION

Our observations suggest emicizumab can facilitate haemostasis for AHA patients and be combined with safer, lower-intensity immunosuppressive therapies to achieve remission.

Acquired Haemophilia A: A Review of What We Know

Autoantibodies against plasma coagulation factors could be developed by some individuals inducing severe and sometimes fatal bleedings. This clinical entity is called acquired haemophilia. It should be suspected in subjects with acute abnormal bleedings, without personal or familiar history of congenital bleeding disorders with an unexplained prolonged aPTT. It is rare disease, although its incidence may be underestimated due to the low knowledge about it by many specialists, the frequent use of anticoagulant or antiplatelet therapies in the affected population that can mask the diagnosis and, sometimes, a so withering effect that avoid its confirmation. Mortality ranges between 9% and 33% depending on the series in the first 2 months after diagnosis. This mortality is attributed in up to 40% of the cases to infections in the context of immunosuppressive treatments used to eliminate the inhibitor. Factor VIII levels below 1% and high inhibitor titers are conditions of worse response rates. Advanced age, patient's ECOG, and underlying conditions are key prognostic factors for response to treatment and patient survival. To reduce morbidity and mortality in these patients, it is important to have clinical knowledge and access to guidelines to achieve an early diagnosis and to optimize the haemostatic and immunosuppressive treatment. This review aims to contribute to the dissemination of basic concepts on the epidemiology etiopathogenesis, diagnosis, treatment and management of these patients, as well as risk factors to get remission and the longest overall survival to allow individualized care. Especial awareness will be proposed in patients with some underlying conditions like cancer, autoimmune diseases, children, pregnancy or drugs.

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.

[Acquired hemophilia and pregnancy: A necessarily multidisciplinary approach]

The occurrence of acquired hemophilia during pregnancy or postpartum is rare (2 to 10 % in series). It is generally suspected in the presence of haemorrhagic manifestations (especially subcutataneous or mucosal bleeding) associated with an isolated prolongation of the activated partial thromboplastin time (APTT). The diagnosis is confirmed by the association of a low level of factor VIII (FVIII) and the presence of an anti-FVIII inhibitor. Postpartum management is similar to that of other acquired haemophilias: correction of a severe haemorrhagic syndrome by "bypassing" agents, eradication of the inhibitor by corticosteroids alone or in combination with another immunosuppressive agent depending on the residual level of FVIII and the titer of the inhibitor. Management of the forms occurring during pregnancy is based on rare experiences or expert opinions. The management of childbirth is particularly delicate in terms of haemorrhage, especially if the anti-FVIII inhibitor is still present, and must be prepared in a multidisciplinary manner. Finally, as with any acquired hemophilia, a relapse is possible, especially in the year following remission. During a subsequent pregnancy, the risk of recurrence is possible but should not be a contraindication to a new pregnancy.

Acquired Haemophilia A: A 15-Year Single-Centre Experience of Demography, Clinical Features and Outcome

Acquired haemophilia A (AHA) is a rare severe bleeding disorder resulting from the production of autoantibodies directed against coagulation factor VIII. At presentation, bleeding events can be severe, and an early diagnosis and treatment are of major importance. The current study aims to analyse the treated patients who have been diagnosed with AHA for a better understanding of our population and treatment outcome. We conducted a retrospective study with 26 patients who had been diagnosed with AHA and who were treated in our hospital between January 2006 and January 2021. The patients ranged in age from 30 to 85 years old: 46.10% were men, 46.10% had no known underlying condition, 27% had an underlying malignancy, 7.60% presented with other diseases: psoriatic arthritis and Paget's disease, and 19.30% presented with AHA during puerperium. All of the patients had bleeding events and were treated with bypass agents for this as well as with immunosuppressive therapy to eradicate the inhibitor. A total of 53.80% of the patients had major bleeding. Sixty-nine percent of the patients achieved complete remission, but 26.90% died during the follow-up, although bleeding was not the cause of death in any of these cases. Our observations underline the importance of clinical suspicion and early referral to centres with experience and laboratory facilities for managing AHA.

Acquired haemophilia A: Italian Consensus Recommendations on diagnosis, general management and treatment of bleeding

BACKGROUND

Acquired haemophilia A (AHA) is a rare bleeding disorder due to autoantibodies to coagulation factor VIII that may be secondary to autoimmune diseases, cancer, drugs, pregnancy, infections, or be idiopathic. Recurrent bleeding, often severe, mostly in muscles and soft tissues, and isolated prolonged activated partial thromboplastin time (aPTT), in the absence of personal and family history of bleeding, are typical features that should raise the suspicion of AHA. Poor awareness of the disease results in diagnostic delays and inappropriate treatment.

MATERIALS AND METHODS

The Italian Association of Haemophilia Centres (AICE) developed consensus recommendations in cooperation with the Italian Society on Thrombosis and Haemostasis (SISET). The document was shared with scientific societies of specialist physicians, laboratory professionals and pharmacists to spread knowledge about AHA and promote appropriate diagnosis/treatment.

RESULTS

Ready availability of the aPTT mixing test is crucial, although diagnostic confirmation and optimal management require prompt referral of patients to specialised centres with rapidly available diagnostic and therapeutic facilities. If immediate referral is unfeasible, treatment must be undertaken early, under guidance of specialised centres or based on shared protocols. Recommendations about diagnosis, general management and, in bleeding patients, haemostatic therapy using bypassing agents or replacement treatment, including the recently available recombinant porcine factor VIII, are provided, considering the different clinical settings and laboratory facilities.

DISCUSSION

This consensus document aims to improve the overall healthcare pathways for AHA, harmonise the management and therapeutic approaches to newly diagnosed patients and reduce the still relevant complications and mortality in this setting.

Acquired hemophilia A (AHA): underreported, underdiagnosed, undertreated medical condition

Background

Acquired hemophilia A (AHA) is a rare acquired bleeding disorder occurred due to the formation of inhibitory antibodies neutralizing endogenous factor VIII.

Main body

About half the cases are idiopathic. Symptoms include severe and unexpected bleeding that could be life-threatening. High index of suspicion should be raised when unexplained subcutaneous or post-surgical bleeding with isolated prolonged APTT.

Conclusions

Acquired hemophilia A is a rare underdiagnosed underreported acquired hemostatic disorder that presents with sudden usually life-threatening bleeding; it is crucial to raise awareness and suspicion index of clinicians for early diagnosis and treatment to avoid morbidity and mortality.

Acquired Hemophilia A associated with bullous pemphigoid: A rare combination

Acquired Hemophilia A (AHA) is a rare autoimmune disorder, caused by the development of circulating autoantibodies against coagulation factor VIII (FVIII). AHA is associated with bullous pemphigoid in 2% of patients. We report a case of a 74-year-old man admitted with anemia and a tense subcutaneous and muscular hematoma in the right thigh. Blood analysis confirmed AHA. The patient had a recent diagnosis of bullous pemphigoid. Response to bypass agents and corticosteroids was good with bleeding control and normalization of FVIII and negative autoantibodies, respectively. In a 3-month follow-up period after tapering and stopping prednisolone, a relapse occurred, and immunosuppression was reinitiated. An early diagnosis and effective treatment in AHA are essential to reduce morbimortality. A careful tapering of immunosuppression is important to minimize FVIII inhibitor recurrence, as observed in this case.

Management of acquired hemophilia A: results from the Spanish registry

The Spanish Acquired Hemophilia A (AHA) Registry is intended to update the status of AHA in Spain. One hundred and fifty-four patients were included and retrospectively followed for a median of 12 months. Patients were predominantly male (56.3%), with median age at diagnosis of 74 years. AHA was more frequently idiopathic (44.1%) and autoimmune disorder-associated (31.7%). Thirty-four percent of patients were on antithrombotic therapy at diagnosis. Hemostatic treatment was used in 70% of patients. Recombinant activated factor VII was more frequently infused (60.3% vs 20.6% activated prothrombin complex concentrate). Only 1 patient did not achieve control of hemorrhage. Complete remission (CR) was achieved by 84.2% of cases after immunosuppressive therapy. Steroids alone were less efficient than the other strategies (68.2% vs 87.2%, P = .049), whereas no differences existed among these (steroids/cyclophosphamide, 88.5%, vs steroids/calcineurin inhibitors, 81.2%, vs rituximab-based regimens, 87.5%). Female sex and high inhibitor levels influenced CR negatively. Thirty-six deaths (23.8%) were reported. Main causes of death were infection (15 patients, 9.9%) and hemorrhage (5 patients, 3.3%). All hemorrhage-related and half the infection-related deaths occurred within 2 months of diagnosis. Prior antithrombotic therapy was inversely associated with survival, irrespective of age. Median age of nonsurvivors was significantly higher (79 vs 73 years in survivors). Patients dying of infection were older than the other nonsurvivors (85 vs 78 years). In summary, fatal infection in the first months is common in our series. Antithrombotic therapy is associated with mortality. Particular care should be taken to avoid misdiagnosis.

Characteristics of Acquired Inhibitors to Factor VIII and Von Willebrand Factor Secondary to Systemic Lupus Erythematosus: Experiences From a Chinese Tertiary Medical Center

OBJECTIVE

Because acquired hemophilia (AH) is a rare entity in systemic lupus erythematosus (SLE), we aimed to investigate the clinical features of SLE-related AH in Chinese patients.

METHODS

This is a medical records review study carried out at a large tertiary care hospital in China from years 1986 to 2018. We searched the case database in Peking Union Medical College Hospital using the International Classification of Diseases. The clinical data on SLE-related AH patients were collected.

RESULTS

A total of 9282 SLE patients had been hospitalized. Six female SLE-related AH patients were identified. Four patients had acquired hemophilia A (AHA), and 2 patients had acquired von Willebrand syndrome. Their mean age was 33.67 ± 13.77 years. Five patients had active disease. The mean SLE disease activity index measured at the time of diagnosis of AH was 10.50 ± 5.28. The average level of activated partial thromboplastin time was 86.5 seconds. Coexistence of secondary antiphospholipid syndrome and AHA was found in one case, and pulmonary embolism was observed 3 years later. After immunosuppressive therapy and symptomatic treatment, an overall remission rate of 83.3% was achieved.

CONCLUSIONS

The frequency of SLE-related AH was low. The development of AH in SLE patients frequently occurs with active disease. The AH could be the first clinical presentation of SLE. Secondary antiphospholipid syndrome and AHA could appear in the same SLE patient. Early and aggressive treatment contributes to a favorable prognosis.

Hemostatic therapy as a management strategy for acquired hemophilia: what does the future hold?

Introduction: Acquired hemophilia A (AHA) is a rare autoimmune disease caused by autoantibodies that bind and inactivate factor VIII (FVIII), predisposing to a potentially life-threatening bleeding.Areas covered: The main epidemiological, clinical, laboratory and therapeutic features of AHA are critically discussed. In particular, we focus on the hemostatic management of AHA patients analyzing the currently available treatment options and showing the latest data on the innovative hemostatic agents still under investigation. Authors searched the Medline and PubMed electronic databases for publication on AHA in the last twenty years.Expert opinion: While a rapid recognition of suspected cases of AHA is essential to make a correct diagnosis and appropriately and timely treat the hemorrhagic manifestations, the multidisciplinary approach to this challenging, rare and life-threatening bleeding disorder is of equal importance to improve patients' outcome. Although promising, the safety and efficacy of the clinical use of emicizumab in AHA needs to be validated by trials including an adequate number of patients, before registering the drug also for this indication.

Bullous pemphigoid is a common associated disorder with acquired haemophilia A

Although the estimated incidence of acquired haemophilia A (AHA) in Singapore is similar to those reported in the literature, we have observed differences in the frequency of their associated diseases, particularly bullous pemphigoid (BP). We investigated the actual incidence of BP among our AHA cohort, their clinical characteristics and treatment outcomes. 6 out of 37 (16%) patients with AHA had BP, making it the most common underlying disorder in our cohort. The median age at diagnosis of AHA was 76 years old with a female preponderance. Most patients had their AHA diagnosed after BP with the median time between BP to AHA diagnosis being 107.5 days. Initial haemostasis was achieved, and factor VIII inhibitor was eliminated in all patients with a median time of disappearance being 52 days. Two patients had recurrence of their factor VIII inhibitor during the tapering of their immunosuppression. There was no relationship between the relapse of BP and AHA. This study suggests that BP is a common association with AHA. These patients respond well to bypassing agent and immunosuppression. However, they have a higher recurrence of factor VIII inhibitor and should be monitored closely for relapse during the tapering period of their immunosuppression.

Inhibitor eradication and bleeding management of acquired hemophilia A: a single center experience in China

Objectives: Acquired hemophilia A (AHA) is a rare disease resulting from autoantibodies against coagulation factor VIII that leads to spontaneous bleeding. This study reports the clinical characteristics and treatment outcomes of a relatively sizable cohort of patients with AHA. Methods: We retrospectively analyzed the characteristics and outcomes of 42 patients with AHA diagnosed in our center from January 2014 through December 2018. Results: The FVIII activity (FVIII: C) was significantly suppressed (median 1.5%; interquartile range [IQR]: 0.9-3.5) by FVIII inhibitor (median 8 BU/mL; IQR: 4.0-16.0). Bypassing agents, PCC or FVIIa, were used in 14 patients for bleeding control without any adverse reaction; and most patients (90.5%, 38/42) were placed on immunosuppressive regimen, corticosteroid alone or in combination with cyclophosphamide. Patients treated with corticosteroids alone had a lower median inhibitor titer (8 BU/mL) than those treated with combination corticosteroids of cyclophosphamide (16 BU/mL) (p < 0.001). 97.4% (37/38) patients achieved complete remission (CR) after immunosuppression therapy, and the median time to CR in patients treated with corticosteroids alone was shorter than those with combination corticosteroids of cyclophosphamide (median 40 days; IQR: 31-65 vs. 51 days; IQR: 38-83, p = 0.301). 10 (26.3%) patients relapsed thereafter and were placed on combined corticosteroid and cyclophosphamide treatment, which yielded second remission in 8 patients (80%). Two patients died, one from uncontrolled post-surgical retroperitoneal hemorrhage and one from sepsis complicating corticosteroid therapy. Conclusion: The corticosteroid achieves a satisfactory outcome, particularly with low inhibitors titers; and combination of cyclophosphamide will facilitate remission in sever patients with high titers of inhibitors.

Clinical evaluation of bleeds and response to haemostatic treatment in patients with acquired haemophilia: A global expert consensus statement

BACKGROUND

Acquired haemophilia (AH) is a rare bleeding disorder with significant morbidity and mortality. Most patients initially present to physicians without experience of the disease, delaying diagnosis and potentially worsening outcomes. Existing guidance in AH is limited to clinical opinion of few experts and does not address monitoring bleeds in specific anatomical locations.

AIM

Derive consensus from a large sample of experts around the world in monitoring bleeding patients with AH.

METHODS

Using the Delphi methodology, a structured survey, designed to derive consensus on how to monitor bleeding patients with AH, was developed by a steering committee for completion by a group of haematologists with an interest in AH. Consensus was defined as ≥75% agreement with a given survey statement. After three rounds of survey refinement, a final list of consensus statements was compiled.

RESULTS

Thirty-six global specialists in AH participated. The participants spanned 20 countries and had treated a median of 12.0 (range, 1-50) patients with AH within the preceding 5 years. Consensus was achieved in all items after three survey rounds. In addition to statements on general management of bleeding patients, consensus statements in the following areas were presented: urinary tract, gastrointestinal tract, muscles, skin, joints, nose, pharynx, mouth, intracranial and postpartum.

CONCLUSIONS

Here, we present consensus statements derived from a broad sample of global specialists to address monitoring of location-specific bleeds and evaluating efficacy of bleeding treatment in patients with AH. These statements could be applied in practice by treating physicians and validated by individual population surveys.

Relapse pattern and long-term outcomes in subjects with acquired haemophilia A

INTRODUCTION

Acquired haemophilia A (AHA) is a rare autoimmune bleeding disorder caused by neutralizing antibodies against factor VIII (FVIII). Despite significant initial morbidity and mortality, most patients achieve remission with immunosuppressive therapy.

AIM

Long-term follow-up data from the Quebec Reference Centre for Inhibitors (QRCI) were analysed to identify factors predictive of AHA relapse and the influence of relapse on survival.

METHODS

Criteria used to define AHA were levels of FVIII <0.3 IU/mL and FVIII inhibitor titres ≥0.6 Bethesda Units (BU). Complete remission was defined as FVIII >0.5 IU/mL and/or FVIII inhibitor titres <0.6 BU while not on immunosuppression.

RESULTS

Between 2000 and 2012, 111 subjects met the inclusion criteria and were followed for a median of 25.6 months. Ninety per cent of them reached remission on immunosuppression in a median time of 45 days. Fourteen patients presented one or more relapses in a median time of 13.4 months. Most relapse episodes were successfully treated. Associated lymphoproliferative syndromes (LPS) were predictive of relapse, whereas FVIII activity and inhibitor titres at initial diagnosis or immunosuppressive regimens were not. The overall survival (OS) was the same, with or without relapse.

CONCLUSION

Among the recognized potential risk factors for relapse, only LPS was statistically significant. The long-term follow-up of our patients also showed that late or multiple relapses may occur, but that relapse is not associated with a worse OS. Thus, long-term follow-up is important for optimal management of AHA.

Prevention and Management of Bleeding Episodes in Patients with Acquired Hemophilia A

Acquired hemophilia A (AHA) is a rare autoimmune disease caused by autoantibodies inhibiting the function of coagulation factor VIII. It is characterized by spontaneous bleeding in patients with no previous family or personal history of bleeding. Although several large registries have collected clinical data on AHA, limited information is available on the optimal management of AHA because controlled clinical trials are lacking. AHA can easily be diagnosed if the problem (prolonged activated partial thromboplastin time in a bleeding patient) is recognized. After the effects of anticoagulants are excluded, low factor VIII activity and the detection of circulating inhibitors confirms the diagnosis. However, lack of familiarity with this rare condition may delay diagnosis and adequate therapy. Treatment of AHA is based on measures for prompt hemostatic control to stop (and prevent) bleeding, immunosuppression to eradicate the autoantibodies, and supportive care for the adverse effects of that treatment and patients' often complex comorbidities. This article gives a comprehensive overview of the current knowledge about the pathophysiology, diagnosis, and treatment of AHA.

Lessons from a systematic literature review of the effectiveness of recombinant factor VIIa in acquired haemophilia

To conduct a systematic review of the literature reporting efficacy and safety of recombinant factor VIIa (rFVIIa) for the treatment of bleeding in acquired haemophilia and, if data permitted, undertake a meta-analysis of the current evidence. MEDLINE^®, Embase^®, and the Cochrane Central Register of Controlled Trials (CENTRAL) databases were searched for all studies on rFVIIa treatment in acquired haemophilia. Heterogeneity of included studies was measured using the inconsistency index (I²). Of the 2353 publications screened, 290 potentially relevant references were identified: 12 studies published in 32 publications met inclusion criteria. In total, 1244 patients and 1714 bleeds were included (671 patients received rFVIIa treatment for 1063 bleeds). In seven of 12 studies, the initial dose of Recombinant FVIIa was 90 ± 10 μg/kg. Recombinant FVIIa was used as first-line therapy in the majority of cases. Median number of doses administered ranged from 10 to 28. Between 68 and 74% of bleeds were spontaneous, whereas 4-50% were traumatic. Thirty-nine to 90% of bleeds were severe. Haemostatic effectiveness was > 90% in 5/6 studies for both patient and bleed level. Recombinant FVIIa had a favourable safety profile with low risk of general adverse events and thromboembolic-associated events. The heterogeneity of the studies and data precluded a meta-analysis. Recombinant FVIIa demonstrated effectiveness for the treatment of bleeds and had a good safety profile. It is apparent from these data that there is a need for more standardised measures of clinical effectiveness in acquired haemophilia to enable comparison and pooling of results in the future.

Factor XIII cotreatment with hemostatic agents in hemophilia A increases fibrin α-chain crosslinking

Essentials Factor XIII (FXIII)-mediated fibrin crosslinking is delayed in hemophilia. We determined effects of FXIII cotreatment with hemostatic agents on clot parameters. FXIII cotreatment accelerated FXIII activation and crosslinking of fibrin and α2 -antiplasmin. These data provide biochemical rationale for FXIII cotreatment in hemophilia.

SUMMARY

Background Hemophilia A results from the absence, deficiency or inhibition of factor VIII. Bleeding is treated with hemostatic agents (FVIII, recombinant activated FVII [rFVIIa], anti-inhibitor coagulation complex [FEIBA], or recombinant porcine FVIII [rpFVIII]). Despite treatment, some patients have prolonged bleeding. FXIII-A2 B2 (FXIII) is a protransglutaminase. During clot contraction, thrombin-activated FXIII (FXIIIa) crosslinks fibrin and α2 -antiplasmin, which promotes red blood cell retention and increases clot stability and weight. We hypothesized that FXIII cotreatment in hemophilia would accelerate FXIII activation, leading to increased fibrin crosslinking. Methods FVIII-deficient plasma and whole blood were clotted with or without hemostatic agents (FVIII, rFVIIa, FEIBA, or recombinant B-domain-deleted porcine FVIII [rpFVIII]) and/or FXIII. The effects on FXIII activation, thrombin generation, fibrin and α2 -antiplasmin crosslinking, clot formation and clot weight were measured by western blotting, calibrated automated thrombography, thromboelastography, and clot contraction assays. Results As compared with FVIII-treated hemophilic plasma, FVIII + FXIII cotreatment accelerated FXIIIa formation without increasing thrombin generation. As compared with buffer-treated or FXIII-treated hemophilic plasma, FVIII treatment and FVIII + FXIII cotreatment increased the generation and amount of crosslinked fibrin, including α-chain-rich high molecular weight species and crosslinked α2 -antiplasmin. In the presence of FVIII inhibitors, as compared with hemostatic treatments (rFVIIa, FEIBA, or rpFVIII) alone, FXIII cotreatment increased whole blood clot weight. Conclusion In hemophilia A plasma and whole blood, FXIII cotreatment with hemostatic agents accelerated FXIIIa formation, increased the generation and amount of fibrin α-chain crosslinked species, accelerated α2 -antiplasmin crosslinking, and increased clot weight. FXIII cotreatment with hemostatic therapy may augment hemostasis through increased crosslinking of fibrin and α2 -antiplasmin.

Hemorrhagic pericardial effusion as the debut of acquired hemophilia in a chronic lymphocytic leukemia patient: A case report, and a review of acquired hemophilia A-related hematological malignancies

BACKGROUND

Acquired hemophilia A (AHA) is a rare bleeding disease caused by autoantibodies against factor VIII. Spontaneous bleeding symptoms usually affect the skin and muscle, while pericardial effusion is an extremely rare manifestation. In the elderly, anticoagulant treatment is frequent and bleeding symptoms are usually associated with this.

CLINICAL FINDINGS

We report a hemorrhagic pericardial effusion as the AHA debut in a patient with untreated chronic lymphocytic leukemia and anticoagulated with apixaban for atrial fibrillation and chronic arterial ischemia. The patient was treated with recombinant activated factor VII to control the active bleeding and corticosteroids and cyclophosphamide to eradicate the inhibitor. In addition, a briefly review of hematological malignancies associated to acquired hemophilia was performed. PARTICULARITIES:: a) anticoagulant treatment may confuse the suspicion of AHA and its diagnosis; b) hemorrhagic pericardial effusion is an extremely rare presentation; c) bypassing agents raise the risk of thromboembolism; d) hematological malignancies rarely cause AHA (<20% of cases).

CONCLUSION

A multidisciplinary team is needed to diagnose and manage AHA effectively. The use of anticoagulants may lead to the misdiagnosis of clinical symptoms. Chronic lymphocytic leukemia is one of the main causes of hematological malignancies associated. The specific treatment of CLL is still recommended in the event of active disease.

Acquired haemophilia in cancer: A systematic and critical literature review

AIM

There is a paucity of data on the clinical presentation and management of cancer patients with acquired haemophilia (AH), we here report a systematic literature review on acquired haemophilia in the context of cancer.

METHODS

Treatment outcomes of AH were defined as complete response (CR), partial response (PR) or no response (NR), based on inhibitor eradication, coagulation factor VIII levels and bleeding control. Reported deaths were either related to cancer or bleeding.

RESULTS

Overall, 105 cases were collected and analyzed according to classification of cancer and efficacy of treatments for inhibitor and malignancy. The mean age was 68 years for both males (range 37-86 years) and females (range 43-89 years), 39 patients were female subjects and 66 were males. A solid cancer was diagnosed in 60 subjects, while 45 patients suffered a haematological malignancy. Solid cancers affected mainly males; however, the incidence of solid tumours vs haematological malignancies was not statistically significant (P = .09). Not all patients were treated for their underlying cancer, bleeding and/or inhibitor, in two cases outcome is unavailable. CR was reported in 62.1% (64/103) cases, PR in 9.7% (10/103) cases, NR with or without death was reported in 28.1% (29/103) cases.

CONCLUSION

CR was best achieved when successful and complete elimination of autoantibodies occurred contemporaneously with the successful treatment of the underlying malignancy. In some cases, recurrent autoantibodies were harbingers of relapsed cancer. Type of cancer, inhibitor titer, treatments administered for bleeding control and inhibitor eradication did not significantly affect clinical outcome of analyzed cases.

Use of recombinant activated factor VII for acute bleeding episodes in acquired hemophilia: final analysis from the Hemostasis and Thrombosis Research Society Registry acquired hemophilia study

The Hemostasis and Thrombosis Research Society Registry was used to monitor the postapproval use and safety of recombinant activated factor VII (rFVIIa). The objective of this article is to evaluate the data from the Hemostasis and Thrombosis Research Society Registry related to rFVIIa-treated bleeding episodes in patients with acquired hemophilia. For each rFVIIa-treated bleeding episode, the initial dose, total dose, average infused dose, number of doses, and treatment duration were calculated. Efficacy was assessed on a three-point scale. Out of the 166 registered patients with acquired hemophilia, 110 patients were treated for 237 bleeding episodes (139 rFVIIa treated); the majority (70%) were in patients older than 60 years. The most frequently reported bleeding locations were subcutaneous (40%) and mucosal (32%). Subcutaneous bleeding episodes were more commonly reported in women (55% vs. 40% men) and white patients (44 vs. 27% black). Of the 139 rFVIIa-treated bleeding episodes, rFVIIa was used as first-line treatment in 127 bleeding episodes. The median initial dose was 90 μg/kg; the median total dose per episode was 333.5 μg/kg. Physician-rated efficacy of rFVIIa for each bleeding episode was reported as 'bleeding stopped' in 85% of bleeding episodes, 'bleeding slowed' in 11% of bleeding episodes, 'no improvement' in 4% of bleeding episodes, and was not documented in 1 bleeding episode. One thromboembolic event was reported; transient neurologic symptoms were reported in a 31-year-old postpartum patient after 110 doses of rFVIIa. Adequate hemostasis was provided for most rFVIIa-treated bleeding episodes at doses largely conforming to the package insert. No major safety concerns were reported.