Acquired inhibitors

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 Rare Complication of Pediatric Idiopathic Multicentric Castleman Disease

Acquired hemophilia is caused by acquired autoantibodies to 1 of the factors of the coagulation cascade, usually factor VIII or IX, and is an exceedingly rare phenomenon in children. The finding of an acquired factor VIII inhibitor in a pediatric patient with idiopathic multicentric Castleman disease has never been reported. Patients with acquired hemophilia can have life-threatening bleeds that are refractory to blood product support, requiring bypassing agents to manage bleeding symptoms. We present the novel finding of acquired hemophilia resulting from an autoantibody to factor VIII in a pediatric patient with idiopathic multicentric Castleman disease and discuss the optimal management of bleeding in a patient with acquired hemophilia.

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.

ORIHIME study: real-world treatment patterns and clinical outcomes of 338 patients with acquired hemophilia A from a Japanese administrative database

BACKGROUND

Acquired hemophilia A (AHA) is a rare disorder, and clinical practices for treating AHA have not been fully clarified in Japan.

OBJECTIVES

This study aims to investigate the epidemiology of AHA and real-world treatment practices in Japan.

PATIENTS/METHODS

This observational study was based on a health administrative database of hospitalized patients diagnosed with AHA who were treated with immunosuppressants.

RESULTS

The study included 214 males and 124 females (mean age 75.7 years). The most frequently used bypassing agent was recombinant activated factor VII. The predominant choice of immunosuppressant for first-line treatment was steroid monotherapy. Median days from the index date to the start of rehabilitation was 65.0 for cardiovascular, 35.5 for respiratory and 23.0 for locomotor. The proportion of patients with an activities of daily living (ADL) score < 70 points was high at both first admission and final discharge (47.4% and 38.8%). The percentage of deaths during hospitalization was 18.6%.

CONCLUSIONS

This study clarified the treatment patterns and clinical outcomes of AHA in a large population in Japan. This was the first study showing ADL score distribution and time to rehabilitation. Further investigation is needed to develop better clinical practices for treatment of AHA.

Targets of autoantibodies in acquired hemophilia A are not restricted to factor VIII: data from the GTH-AH 01/2010 study

The root cause of autoantibody formation against factor VIII (FVIII) in acquired hemophilia A (AHA) remains unclear. We aimed to assess whether AHA is exclusively associated with autoantibodies toward FVIII or whether patients also produce increased levels of autoantibodies against other targets. A case-control study was performed enrolling patients with AHA and age-matched controls. Human epithelial cell (HEp-2) immunofluorescence was applied to screen for antinuclear (ANA) and anticytoplasmic autoantibodies. Screening for autoantibodies against extractable nuclear antigens was performed by enzyme immunoassay detecting SS-A/Ro, SS-B/La, U1RNP, Scl-70, Jo-1, centromere B, Sm, double-stranded DNA, and α-fodrin (AF). Patients with AHA were more often positive for ANA than control patients (64% vs 30%; odds ratio [OR] 4.02, 1.98-8.18) and had higher ANA titers detected than controls. Cytoplasmic autoantibodies and anti-AF immunoglobulin A autoantibodies were also more frequent in patients with AHA compared with controls. Autoantibodies against any target other than FVIII were found in 78% of patients with AHA compared with 46% of controls (OR 4.16, 1.98-8.39). Results were similar preforming sensitivity analyses (excluding either subjects with autoimmune disorders, cancer, pregnancy, or immunosuppressive medication at baseline) and in multivariable binary logistic regression. To exclude that autoantibody staining was merely a result of cross-reactivity of anti-FVIII autoantibodies, we tested a mix of 7 well-characterized monoclonal anti-FVIII antibodies. These antibodies did not stain HEp-2 cells used for ANA detection. In conclusion, a diverse pattern of autoantibodies is associated with AHA, suggesting that a more general breakdown of immune tolerance might be involved in its pathology.

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.

Comprehensive blood coagulation potential in patients with acquired hemophilia A: retrospective analyses of plasma samples obtained from nationwide centers across Japan

Global coagulation potential was assessed in 59 patients with acquired hemophilia A (PwAHA) by clot waveform analysis (CWA) and/or thrombin and plasmin generation assay. Relationships between factor VIII activity (FVIII:C) and the parameters from CWA and T/P-GA in patients with congenital HA were compared by grading coagulation potential related to FVIII:C: T1 (FVIII:C < 1 IU/dL), T2 (1 ≤ , ≤ 5 IU/dL), T3 (5 < , 12 ≤ IU/dL), and T4 (12 < , ≤ 50 IU/dL). The median FVIII:C and inhibitor titers in PwAHA on admission were 3.3 IU/dL and 63.0 BU/mL, respectively, but global coagulation parameters corresponded to T1 or less. Median FVIII:C levels during follow-up in PwAHA were 1.7-9.6-6.7-40.0-21.7 IU/dL on days 0-14-28-56-93, respectively. CWA-based data corresponded to less than T2 until day 28, but more closely reflected FVIII:C after day 56. Peak thrombin was severely low (near T1) until day 28 and improved modestly after day 56 but remained less than T2. Peak plasmin was lower than T1 until day 56, and returned to T4 on day 93. In conclusion, global coagulation function in PwAHA was impaired to a greater extent than could be anticipated from assays of FVIII:C, until approximately 1 month after immunosuppression and treatment with FVIII-bypassing agents.

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.

Acquired Hemophilia A and urothelial carcinoma

Acquired Hemophilia A (AHA) is a rare entity, resulting from the production of autoantibodies against Factor VIII of the coagulation cascade. These autoantibodies may develop in response to autoimmune conditions, drugs, neoplastic diseases, and pregnancy. Diagnosis involves clinical presentation, mucocutaneous or intramuscular bleeding, and laboratory findings, such as prolonged activated partial thromboplastin time, decreased levels of Factor VIII, and the presence of Factor VIII autoantibodies. The etiology is diverse, with a variety of underlying culprits. Malignancy-associated AHA has been associated with approximately 15% of cases. Urothelial malignancy-mediated AHA is exceedingly rare, with only two previously published reports. The management of AHA includes stabilization and control of bleeding via the use of hemostatic agents, and elimination of the inhibitor with immunosuppressive therapy. Here, we report a case of AHA secondary to urothelial malignancy and review the pathobiology and pathogenesis of Hemophilia A and AHA.

Acquired haemophilia as a paraneoplastic manifestation of pancreatic cancer

Acquired haemophilia is a severe haematological disorder characterised by the presence of anti-factor VIII antibodies. Although rare, it can lead to serious bleeding complications. Acquired haemophilia can be seen in patients with malignancies as a paraneoplastic phenomenon. This is a case of a 52-year-old patient who presented with haematuria and retroperitoneal bleeding soon after being diagnosed with pancreatic adenocarcinoma and subsequently was found to have acquired haemophilia. The treatment of underlying malignancy with chemotherapy may accelerate the eradication of anti-factor VIII antibodies.

Utilization of Emicizumab in Acquired Factor VIII Deficiency

BACKGROUND Acquired hemophilia A (AHA) is a rare autoimmune disease caused by immunoglobulins that bind and inactive factor VIII, thereby predisposing to life-threatening bleeding. Bleeding is typically stabilized by utilizing bypassing agents, such as recombinant factor VIIa (rVIIa). Select case reports have demonstrated the success of alternative prophylaxis for clearance of factor VIII inhibitors through the use of emicizumab, a current FDA approved medication for treatment of congenital hemophilia A. In this case report we present the efficacy of utilizing emicizumab as a prophylactic agent in a patient that was unable to tolerate first-line therapy for prophylaxis. CASE REPORT A 91-year-old male presented for ongoing hematuria for 5 weeks with prior workup unrevealing. He was given a day's course of recombinant factor VIIa to stabilize his bleeding and was started on cyclophosphamide and prednisone after a revealing hematological workup including activated partial thromboplastin time (aPTT) >100 seconds and factor VIII inhibitor level of 44 BU/mL. He continued to require VIIa infusions to control his bleeding and was started on emicizumab once stabilized. His bleeding remained controlled and his inhibitor decreased after 6 months of therapy with repeat factor VIII inhibitor level of 1.9 BU/mL. CONCLUSIONS The success of utilizing emicizumab for bleeding prophylaxis in AHA is demonstrated by this patient's resolution of bleeding. The high frequency of dosing and higher risk for thrombosis with factor VIIa, in conjunction with our patient's medical history and ease of administration, make emicizumab an ideal agent for bleeding prophylaxis while awaiting clearance of factor VIII inhibitors.

Advances in managing rare acquired bleeding disorders

INTRODUCTION

Rare acquired bleeding disorders include a wide spectrum of coagulopathies characterized by spontaneous or post-trauma and post-surgery hemorrhages in patients without a previous personal or family history of bleeding.

AREAS COVERED

This review, based on a Medline/PubMed search during the last 20 years, will focus mainly on rare acquired bleeding disorders caused by autoantibodies against coagulation factors, including autoantibodies against factor VIII (acquired hemophilia A), von Willebrand factor (acquired von Willebrand syndrome) and other coagulation factors (factors V, X, XI, and XIII). The pathogenic, laboratory, and clinical features of these rare hemorrhagic conditions will be discussed, with particular attention to their management.

EXPERT OPINION

The treatment of rare acquired bleeding disorders includes the control of bleeding and the elimination of the autoantibody and of the underlying disease, when present. As the bleeding clinical phenotype is often severe, the management of affected patients is particularly challenging. Thus, while an early diagnosis of the acquired coagulopathy is essential to start the most appropriate treatment and to improve patients' outcomes, the support of specialized centers is equally important to provide a correct management of such complicated cases.

An anti-factor IXa/factor X bispecific antibody, emicizumab, improves ex vivo coagulant potentials in plasma from patients with acquired hemophilia A

INTRODUCTION

Acquired hemophilia A (AHA) is caused by autoantibodies against factor (F)VIII, and is characterized by severe, spontaneous bleeding, which can be life-threatening. Emicizumab, an anti-FIXa/FX bispecific antibody, significantly reduces bleeding events in congenital hemophilia A (HA) with and without inhibitors. The known pathophysiological mechanisms and current preclinical data in HA suggest that emicizumab could provide effective treatment for AHA, but the coagulation activities of emicizumab in these patients remain unknown.

AIM

To evaluate the coagulant effects of emicizumab in plasma from AHA patients.

METHODS AND RESULTS

Tissue factor-triggered thrombin generation assays using normal plasma preincubated with anti-FVIII monoclonal antibodies recognizing different epitopes demonstrated that 20 µg/mL emicizumab recovered the depressed peak levels of thrombin generation to 46% to 72%. Further studies were devised, therefore, to simulate the clinical course in AHA patients, including during the acute phase for severe bleeding requiring FVIII-bypassing therapy, and during the subacute/chronic phase with less bleeding. Various concentrations of emicizumab were used to represent the potential changes in plasma levels based on the half-life of the antibody (~30 days). The ex vivo addition of emicizumab to plasma samples from AHA patients (n = 16) increased peak thrombin in all cases, irrespective of the inhibitor epitope specificity. Thrombin generation at 20 and 100 µg/mL emicizumab was restored to (median) 43.9% and 92.2%, respectively. Differences were evident in some cases, however, and recovery rates appeared likely to be greater in patients with type 2 inhibitor than those with type 1.

CONCLUSION

Emicizumab improved ex vivo coagulation potential in plasma from AHA patients.

Acquired factor VIII deficiency in prostate adenocarcinoma presenting as multiple hematomas and hemarthrosis

Acquired hemophilia A or acquired factor VIII deficiency is a rare bleeding disorder due to the presence of autoantibodies to factor VIII. It has been associated with autoimmune conditions, certain medications, and malignancy. It has a high morbidity and mortality, and early diagnosis and treatment is critically important. Acquired hemophilia A usually manifests with soft tissue bleeding, such as epistaxis, genitourinary, or gastrointestinal bleeding and rarely with hemarthrosis. In this case report, we present the management of an uncommon case of acquired hemophilia A in a patient with metastatic prostate adenocarcinoma who presented with both hemarthrosis and soft tissue bleeding. Bleeding was controlled with recombinant factor VIIa, factor VIII bypassing agent, and immunosuppressive therapy with prednisone and rituximab. Chemotherapy with docetaxel was also promptly initiated to address the underlying condition and achieve long-term remission, which is currently ongoing for 10 months.

Acquired Hemophilia A with Gastrointestinal Bleeding

Peptic ulcer disease is the most common cause of acute gastrointestinal bleeding, followed by variceal bleeding, Mallory–Weiss syndrome, and malignancy. On the contrary, acquired hemophilia A is a very rare hemorrhagic disease, which usually manifests with musculocutaneous bleeding, caused by autoantibodies against coagulation factor VIII.

A 78-year-old man presented to the Emergency Department with melena. Dieulafoy’s lesions were observed on, and endoscopic cauterization was performed. However, the patient complained of back pain and symptoms indicative of upper gastrointestinal bleeding. Abdominopelvic computed tomography was performed, and hematoma in the psoas muscle was detected. Antibodies against coagulation factor VIII were confirmed with a blood test, and the diagnosis of acquired hemophilia A was made. Here, we report a case of acquired hemophilia A presenting with upper gastrointestinal bleeding symptoms and present a brief review of literature.

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.

Acquired hemophilia A: a review of recent data and new therapeutic options

OBJECTIVES

Acquired hemophilia A (AHA) is a rare, but potentially life-threatening, bleeding disorder caused by an autoantibody against factor VIII that interferes with its coagulant function.

METHODS

We performed a narrative review focusing on the diagnostic aspects of AHA and on the current treatment strategies with particular regard to new data and therapeutic developments.

RESULTS

The management of this severe hemorrhagic disorder is based on the control of bleeding with the use of bypassing agents and on the utilization of a variety of immunosuppressant agents with the goal of eliminating the autoantibody permanently.

CONCLUSION

The optimal management of AHA should be multidisciplinary and requires a close collaboration between physicians from various specialties.

Anti–factor VIII IgA as a potential marker of poor prognosis in acquired hemophilia A: results from the GTH-AH 01/2010 study

This study is the first to assess the prognostic value of FVIII-specific antibody data in patients with AHA. Anti-FVIII IgA, but not immunoglobulin G, autoantibodies at baseline are potential predictors of recurrence and poor outcome of AHA.

A Hematological Menace: Multiple Venous Thrombosis Complicated by Acquired Factor VIII Deficiency

Patient: Male, 21

Final Diagnosis: Acquired Factor VIII Deficiency

Symptoms: Abdominal hematoma • DVT • life threatening bleeding

Medication: —

Clinical Procedure: Life saving medical therapy

Specialty: Hematology

A case series of acquired haemophilia in a Malaysian hospital: unpredictably rare medical emergency

Acquired haemophilia (AH) is a rare bleeding disorder characterized by the presence of acquired inhibitors against Factor VIII causing disruption of coagulation cascade. It has no known genetic inheritance, and diagnosis remains a challenge. The peculiar presentations are later age of onset as acute pain in weight-bearing joints and spontaneous muscle haematoma with isolated prolonged activated partial thrombin time (APTT). Prevalence is 1 per million per year affecting both genders equally where blood product transfusion is seen in almost 87% of cases. The direct cause of AH is still unknown, and autoimmune dysregulation has been postulated, which predisposes to the development of the factor inhibitors. Being extremely rare, we are reporting two consecutive patients diagnosed by unusual bleeding episodes with isolated prolonged APTT due to Factor VIII inhibitors. AH deserves a special mention as high index of suspicion is required. More studies are required to provide better guidance in diagnosis and management of this condition.

The anti-CD20 monoclonal antibody rituximab to treat acquired haemophilia A

BACKGROUND

Acquired haemophilia A (AHA) is a rare bleeding disorder caused by the development of specific autoantibodies against naturally occurring factor VIII (FVIII). Although about half of cases are idiopathic, AHA may be associated with several non-neoplastic conditions, autoimmune disorders, as well as haematological malignancies, such as chronic lymphocytic leukaemia and lymphoma. The long-term suppression of inhibitors is one of the mainstays of the treatment of AHA. Apart from standard immunosuppressive treatments, rituximab has been proven to be effective in AHA.

MATERIALS AND METHODS

The aim of this review is to provide a systematic description of data available in the literature on this topic. To do so, we performed a search using the indexed online database Medline/PubMed, without temporal limits, matching the words "rituximab" and "acquired h(a)emophilia". Furthermore, additional published studies were identified in the reference list of the publications found in PubMed.

RESULTS

The review of the literature confirms that rituximab may be a safe and useful treatment for AHA.

DISCUSSION

Although rituximab is not a standard therapy for AHA, it may be useful in resistant cases. However, the definitive place of this monoclonal antibody in the therapeutic strategy for AHA (first or second-line, alone or in combination with other drugs) remains to be determined more precisely and warrants further investigation.

Successful immunoadsorption of life-threatening bleeding in factor VIII inhibitor disease, but no long-term remission with anti-CD20 treatment

A 62-year-old man and a 64-year-old woman presented to our institution with acquired haemophilia A. They both developed life-threatening bleeding. Immunoadsorption using protein A columns was used to rapidly lower factor VIII inhibitor levels. Immunosuppression with steroids and the anti-CD20 antibody, rituximab, was instituted. Yet their effects were either partial or complicated by an early relapse. Repetitive cyclophosphamide administration led to a sustained immunological response. While immunoadsorption appears effective and safe to lower factor VIII inhibitor levels, it seems that further preferably randomised controlled trials are needed to establish the value of rituximab versus the standard immunosuppressive regime comprising cyclophosphamide.

Acquired hemophilia A: emerging treatment options

Acquired hemophilia A is a rare autoimmune disorder caused by an autoantibody (inhibitor) to factor VIII (FVIII) that interferes with its coagulant function and predisposes to severe, potentially life-threatening hemorrhage. Disease management focuses on controlling bleeding, primarily with the use of bypassing therapy and recombinant porcine FVIII, and permanently eradicating the autoantibody using various immunosuppressants. Treatment challenges include delayed diagnosis, difficulty achieving hemostasis and durable remissions, and complications associated with the use of hemostatic and immunosuppressive therapy in a primarily older patient population.

Acquired haemophilia A: the importance of early recognition in cases of spontaneous bleeding in the elderly

We describe the case of a 79-year-old man who presented 'off legs' with acute right leg pain. He was initially treated for suspected cellulitis but subsequently found to have spontaneous soft tissue bleeding into the right thigh. He was eventually diagnosed with idiopathic acquired haemophilia A and treated with activated prothrombin complex concentrates to control acute bleeding followed by immunosuppressant therapy. Acquired haemophilia A is a potentially life-threatening and under-recognised bleeding disorder that results from the immune-mediated development of autoantibodies directed against coagulation factor VIII. The disease is more common in elderly individuals where early recognition and treatment is compounded by the presence of other comorbid conditions, including other potential causes of bleeding. These confounding factors and lack of awareness among non-specialists accounts for the delay in diagnosis that is common in this disease and contributes to the persistently high mortality in this age group.

Acquired hemophilia A: a frequently overlooked autoimmune hemorrhagic disorder

Acquired hemophilia A (AHA) is a rare hemorrhagic disease in which autoantibodies against coagulation factor VIII- (FVIII-) neutralizing antibodies (inhibitors) impair the intrinsic coagulation system. As the inhibitors developed in AHA are autoantibodies, the disease may have an autoimmune cause and is often associated with autoimmune disease. Although acute hemorrhage associated with AHA may be fatal and is costly to treat, AHA is often unrecognized or misdiagnosed. AHA should thus be considered in the differential diagnosis particularly in postpartum women and the elderly with bleeding tendency or prolonged activated partial thromboplastin time. Cross-mixing tests and measurement of FVIII-binding antibodies are useful to confirm AHA diagnosis. For treatment of acute hemorrhage, hemostatic therapy with bypassing agents should be provided. Unlike in congenital hemophilia A with inhibitors, in which immune tolerance induction therapy using repetitive infusions of high-dose FVIII concentrates is effective for inhibitor eradication, immune tolerance induction therapy has shown poor efficacy in treating AHA. Immunosuppressive treatment should thus be initiated to eradicate inhibitors as soon as the diagnosis of AHA is confirmed.

Acquired hemophilia A as a cause of acute upper gastrointestinal hemorrhage

A 71-year-old man presented to the emergency department with his first episode of hematemesis. He was anemic and coagulopathic on admission, and became hemodynamically unstable requiring surgical intervention to control the bleeding. Prior to surgery, he required 100% plasma exchange with human plasma derived prothrombin complex concentrate (Octaplex) as the exchange fluid. At induction of anesthesia, he received tranexamic acid, prothrombin complex concentrate, and platelets. At the time of knife to skin, he was given coagulation factor VIIa intravenously as a bolus. This treatment was on the recommendation of the hematology team who suspected a diagnosis of acquired hemophilia on the basis of his history and coagulation screen. His bleeding was controlled and a diagnosis of acquired hemophilia A was confirmed in the postoperative period. This was managed with immunosuppressive therapy, and at the 2 year follow-up he remains well and is off all treatment.

Acquired haemophilia A: a 2013 update

Acquired haemophilia A (AHA) is a rare but often severe bleeding disorder caused by autoantibodies against coagulation factor VIII (FVIII). AHA occurs more frequently in the elderly and in association with several conditions, such as the post-partum period, malignancies, autoimmune diseases or drug exposure; however, approximately 50% of reported cases are apparently idiopathic. Beside the elimination of the underlying disorder, the therapeutic approach to AHA should be directed toward the control of acute bleed and the eradication of FVIII autoantibody production. In this narrative review, we summarise the current knowledge on the epidemiology, diagnosis and clinical features of AHA, focusing in particular on advances in the management of this challenging bleeding disorder.

Immune Tolerance Therapy in Patients with Acquired Hemophilia

Acquired hemophilia is a rare disorder with an estimated annual incidence of 0.2-1 cases per million individuals. The etiology of the disorder remains obscure, although approximately half of all cases are associated with other underlying conditions. In acquired hemophilia, the severe hemorrhagic diathesis is caused by the development of autoantibodies directed against a clotting factor, most commonly factor VIII. These autoantibodies inhibit normal coagulation and lead to bleeding complications, which can be life-threatening in a high percentage of cases. Prompt diagnosis and appropriate management of the disorder enable effective control; the short- and long-term aims of therapy are to terminate the acute bleed and eliminate or reduce the inhibitor, respectively. Immune tolerance therapy has been shown to successfully eradicate or suppress inhibitors in patients with congenital hemophilia A and may be applicable to patients with acquired hemophilia. Here we present preliminary data on the use of immune tolerance therapy in patients with acquired hemophilia and discuss possible treatment strategies.

Recombinant Activated Factor VII in Patients at High Risk of Bleeding

Currently, recombinant activated factor VII (rFVIIa) (NovoSeven) is indicated for the treatment of spontaneous and surgical bleeding in congenital haemophilia A and B patients with inhibitors to factors VIII (FVIII) and IX (FIX) >5 Bethesda units (BU) worldwide, and in patients with acquired haemophilia, congenital FVII deficiency and Glanzmann's thrombasthenia in Europe. Until April 2003, almost three-quarters of a milion doses of rFVIIa have been administered proving its efficacy and excellent safety record. According to results from initial clinical trials and a large number of case reports, the rFVIIa may be effective not only in treating haemophilia patients but also in treatment of bleeding in patients on oral anticoagulation or heparin, patients with liver diseases, von Willebrand disease (vWD), thrombocytopenia, various platelet defects, congenital or acquired deficiency of FVII, and in subjects without any pre-existing coagulopathy with diffuse life-threatening bleeding triggered by surgery or trauma. This review will briefly summarize rFVIIa mode of action in haemostasis, the current clinical experience with rFVIIa and focus on the alternative use of rFVIIa in patients at the high risk of bleeding in both spontaneous cases and clinical trials reports.

Management of acquired haemophilia bleed in the backdrop of multiple myeloma

Acquired haemophilia A is an uncommon, potentially life-threatening disorder caused by onset of auto-antibodies against coagulation factor VIII. The association of acquired haemophilia and multiple myeloma is extremely rare. Prompt diagnosis of this acquired bleeding disorder is essential for management, aimed at haemorrhage control and inhibitor suppression. We describe a case of acquired haemophilia in a patient with multiple myeloma.

Acquired hemophilia a: retrospective analysis of 49 cases from a single Chinese hemophilia center

Acquired hemophilia A (AHA) is a rare bleeding disorder caused by the autoantibody directed against factor VIII in patients without previous history of a bleeding disorder. We retrospectively analyzed the characteristics and outcomes of 49 patients with AHA diagnosed in our center from February 1994 to October 2012. Twenty-four patients with acute bleeding episodes were treated with prothrombin complex concentrate (PCC) at a relative low dose of 30 to -50 U/kg/d and achieved good outcomes without any adverse reaction. Corticosteroids alone or in combination with cyclophosphamide were used as the first-line therapy to eradicate the inhibitors. In 39 evaluable patients, 35 (89.7%) achieved complete remission (CR). This study demonstrates that when bypassing agents such as recombinant activated factor VII and activated PCCs are not affordable or available, low dose PCC is effective and safe to control acute bleeding in patients with AHA. First-line therapy achieved good outcomes with a CR rate of 89.7%.

Duodenal tumor presenting as acquired hemophilia in an 88-year-old woman: a clinical case and review of the literature

Acquired hemophilia is a rare disease, presenting with severe hemorrhage, we present a case caused by a duodenal tumor, the clinical management, ethical implications, treatment recommendations, and a review of the literature.

Ischemic stroke after recombinant factor VIIa treatment in acquired hemophilia A patient

Acquired hemophilia is a rare, life-threatening coagulopathy in adults caused by the development of autoantibodies against factor VIII. Bypass agents such as recombinant factor VIIa (rFVIIa) are usually preferred for bleeding control; however, thromboembolic complications may occur. We report here a case that presented with extensive cutaneous and mucosal bleedings due to factor VIII inhibitors and was treated successfully with rFVIIa and steroid therapy, but was complicated with a life-threatening thromboembolic attack during follow-up.

Failure of fresh frozen plasma infusion and vitamin K to correct elevated international normalised ratio

An 83-year-old, otherwise well, Caucasian gentleman was admitted with an incarcerated inguinal hernia. Routine preoperative tests revealed a raised international normalised ratio of 7.4, prothrombin time of 72.1 s and activated partial thromboplastin time of 73.1 s with normal liver and renal function tests. Despite fresh frozen plasma 15 ml/kg, and vitamin K, his repeat clotting remained deranged. The patient went on to have his hernia repair, and intraoperative bleeding remained normal despite the deranged clotting. The presence of endogenous clotting inhibitors can cause deranged coagulation studies but not impair bleeding. As in this case, the patient underwent surgery with no abnormal bleeding.

LDL-apheresis: technical and clinical aspects

The prognosis of patients suffering from severe hyperlipidemia, sometimes combined with elevated lipoprotein (a) levels, and coronary heart disease refractory to diet and lipid-lowering drugs is poor. For such patients, regular treatment with low-density lipoprotein (LDL) apheresis is the therapeutic option. Today, there are five different LDL-apheresis systems available: cascade filtration or lipid filtration, immunoadsorption, heparin-induced LDL precipitation, dextran sulfate LDL adsorption, and the LDL hemoperfusion. There is a strong correlation between hyperlipidemia and atherosclerosis. Besides the elimination of other risk factors, in severe hyperlipidemia therapeutic strategies should focus on a drastic reduction of serum lipoproteins. Despite maximum conventional therapy with a combination of different kinds of lipid-lowering drugs, sometimes the goal of therapy cannot be reached. Hence, in such patients, treatment with LDL-apheresis is indicated. Technical and clinical aspects of these five different LDL-apheresis methods are shown here. There were no significant differences with respect to or concerning all cholesterols, or triglycerides observed. With respect to elevated lipoprotein (a) levels, however, the immunoadsorption method seems to be most effective. The different published data clearly demonstrate that treatment with LDL-apheresis in patients suffering from severe hyperlipidemia refractory to maximum conservative therapy is effective and safe in long-term application.

Acquired haemophilia secondary to ivabradine presenting with acute respiratory distress syndrome

The authors present the case of a 72-year-old patient who presented with severe dyspnoea, scant haemoptysis, pronounced desaturation and bilateral haematomas on the upper limbs. Chest radiography showed bilateral infiltrates mainly in the lower lobes. The patient's prothrombin time, and platelet count were normal. However, the activated partial thromboplastin time showed a prolongation that was not reversed on a correction study. Factor VIII (FVIII) levels were very low and evidence of FVIII inhibitor was found. The patient had started taking ivabradine 2 months earlier, and the diagnosis of idiosyncratic acquired haemophilia was established. The patient was treated with volume expansion therapy, high levels of oxygen, multiple transfusions, methylprednisolone, desmopressine and rituximab. On the 3rd day, the patient showed progressive amelioration of his dyspnoea, oxygen needs and chest infiltrates. On the 7th day, the patient was discharged.

Successful Long Term Eradication of Factor VIII Inhibitor in Patients with Acquired Haemophilia A in Saudi Arabia

Acquired haemophilia A is a serious and potentially fatal bleeding disorder. Diagnosis is difficult and maybe delayed due to its rarity. The high mortality rate and the complex nature of treatment necessitate patient management at a haemophilia centre, where the required expertise and resources are available. Prompt diagnosis is crucial and early initiation of therapy could be life saving. Management includes initial control of bleeding followed by an approach to eradicate the coagulation factor inhibitor. In this paper we describe our local experience with acquired haemophilia A, which resulted in the successful control of major bleeding at presentation and eradication of inhibitors.

Demographic and clinical data in acquired hemophilia A: results from the European Acquired Haemophilia Registry (EACH2)

BACKGROUND

Acquired hemophilia A (AHA) is a rare autoimmune disease caused by autoantibodies against coagulation factor VIII and characterized by spontaneous hemorrhage in patients with no previous family or personal history of bleeding. Although data on several AHA cohorts have been collected, limited information is available on the optimal management of AHA.

OBJECTIVES

The European Acquired Hemophilia Registry (EACH2) was established to generate a prospective, large-scale, pan-European database on demographics, diagnosis, underlying disorders, bleeding characteristics, treatment and outcome of AHA patients.

RESULTS

Five hundred and one (266 male, 235 female) patients from 117 centers and 13 European countries were included in the registry between 2003 and 2008. In 467 cases, hemostasis investigations and AHA diagnosis were triggered by a bleeding event. At diagnosis, patients were a median of 73.9 years. AHA was idiopathic in 51.9%; malignancy or autoimmune diseases were associated with 11.8% and 11.6% of cases. Fifty-seven per cent of the non-pregnancy-related cases were male. Four hundred and seventy-four bleeding episodes were reported at presentation, and hemostatic therapy initiated in 70.5% of patients. Delayed diagnosis significantly impacted treatment initiation in 33.5%. Four hundred and seventy-seven patients underwent immunosuppression, and 72.6% achieved complete remission.

CONCLUSIONS

Representing the largest collection of consecutive AHA cases to date, EACH2 facilitates the analysis of a variety of open questions in AHA.