Selective B-cell depletion with rituximab for the treatment of patients with acquired hemophilia

First-line immunosuppressive therapies for acquired hemophilia A: A 25-year cohort experience and network meta-analysis

Acquired hemophilia A (AHA) presents a significant bleeding risk. Management involves bleeding control and immunosuppressive therapy (IST) to eliminate inhibitors. This study, encompassing a retrospective cohort of 76 newly diagnosed AHA patients (1997-2022), evaluated IST outcomes such as complete remission (CR), relapse, and mortality rates, alongside influencing factors. Supplementing these findings, a systematic review and network meta-analysis compared CR and relapse rates across ISTs, sourcing from Embase, Scopus, and ScienceDirect up to November 2023. In our cohort, demarcated by a 20 Bethesda-unit titer threshold, cyclophosphamide plus prednisolone (CP; n = 64) was the predominant initial IST. Lower inhibitor levels significantly correlated with higher CR rates (86.8 % vs 62.2 %; P = .014) and showed an odds ratio of 0.26 for CR (P = .021). Median relapse-free survival (RFS) extended to 37.13 months, significantly enhanced by CP (hazard ratio, 0.24; 95 % confidence interval, 0.10-0.60; P = .002). Our network meta-analysis, including 1476 CR and 636 relapse patients, indicated CP and rituximab-based ISTs significantly outperformed steroid monotherapy in terms of CR and lower relapse rates (risk differences of 0.15 and -0.13/-0.15, respectively; P < .05), without significant differences between CP and rituximab. Moreover, adding rituximab to the front-line treatment did not produce superior outcomes compared to the CP regimen alone, positioning CP as a viable first-line choice, particularly where rituximab is less accessible. The consideration of IST toxicity remains critical in treatment decisions.

Rituximab for eradicating inhibitors in people with acquired haemophilia A

BACKGROUND

Acquired haemophilia A is a rare bleeding disorder caused by the development of specific autoantibodies against coagulation factor VIII. Standard treatment, usually steroids alone, or in combination with cyclophosphamide, aims to stop acute bleeds by using haemostatic agents to promote clotting. Rituximab may be an alternative approach to the treatment of acquired haemophilia by eradicating FVIII autoantibodies. This is an update of a previously published Cochrane Review.

OBJECTIVES

To assess the efficacy and adverse effects of rituximab for treating people with acquired haemophilia A.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's trials registers, comprising references identified from comprehensive electronic database searches and handsearches of relevant journals and conference proceedings (January 2021). We also undertook searches of CENTRAL, MEDLINE and online trial registries (January 2021).

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials of rituximab for people with acquired haemophilia A, with no restrictions on gender, age or ethnicity.

DATA COLLECTION AND ANALYSIS

No trials matching the selection criteria were eligible for inclusion.

MAIN RESULTS

No trials matching the selection criteria were eligible for inclusion.

AUTHORS' CONCLUSIONS

We found no randomised clinical trials of rituximab for acquired haemophilia A. Thus, we are not able to draw any conclusions or make any recommendations on rituximab for eradicating inhibitors in people with acquired haemophilia A based on the highest quality evidence. Given that undertaking randomised controlled trials in this field is a complex task, we suggest that, while planning such trials, clinicians treating the disease continue to base their choices on alternative, lower-quality sources of evidence. In a future update of this review, we plan to appraise and incorporate eligible randomised controlled trials, as well as other high-quality, non-randomised studies.

Life-threatening bleeding in a patient with pemphigoid-induced acquired hemophilia A and successfully treated with rituximab and rFVIIa: A case report

RATIONALE

Acquired hemophilia A (AHA) is a rare bleeding disorder with prolonged activated partial thromboplastin time (aPTT). Severe hemorrhage may occur, especially in refractory AHA.

PATIENT CONCERNS

We reported a 63-year-old man who suffered from life-threatening bleeding after the onset in lower limbs.

DIAGNOSES

The patient was diagnosed as AHA which was related to pemphigoid.

INTERVENTIONS

The patient had no response to the first-line treatment with corticosteroid and cyclophosphamide. Meanwhile, fatal hemorrhage occurred successively in thoracic cavity and right frontal lobe. rFVIIa and rituximab were administered.

OUTCOMES

The patient survived from the life-threatening hemorrhage with a normal aPTT. His aPTT and FVIII:C level was normal during the follow-up of 6 months.

LESSONS

Rituximab and rFVIIa can play a critical role in rescuing AHA that is refractory to the first-line treatment.

Acquired hemophilia A in a woman with systemic lupus erythematosus: A case report and review of literature

RATIONALE

Acquired hemophilia A (AHA) is a rare autoimmune disease caused by autoantibodies directed against the activity of factor VIII (FVIII) and presents with prolonged bleeding. 5.7% of systemic lupus erythematosus (SLE) patients are affected by AHA.

PATIENT CONCERNS

A 51-year-old female patient with SLE presenting with the fatigue and spontaneous clinical bleeding symptoms such as hematuria and ecchymoses for 1 week.

DIAGNOSIS

Laboratory examinations revealed prolongation of the activated partial thromboplastin time (APTT) (65.7 s), decreased FVIII activity (1.4%), and a titer of FVIII inhibitors of 8.5 Bethesda units/mL.

INTERVENTIONS

Transfusion of recombinant human FVIII (ADVATE) in combination with intravenous methylprednisolone, cyclophosphamide, plasmapheresis, and fresh frozen plasma successfully stopped the bleeding and reduced the level of FVIII inhibitor.

OUTCOMES

The size of the hematoma slowly decreased. The skin ecchymosis was gradually absorbed, the hemoglobin count increased, and the coagulation index gradually improved. There was no new bleeding or bleeding site. The patient was discharged and transferred to a local hospital for hospice care.

LESSONS

AHA in a patient with SLE is rare. Once it occurs, it can be life-threatening. Clinicians should remain aware that because some cases of AHA may have features of SLE, appropriate distinction and diagnosis of these different but associated diseases is necessary.

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.

Overshoot of FVIII activity in patients with acquired hemophilia A who achieve complete remission

Acquired hemophilia A (AHA) is a rare, life-threatening bleeding disorder caused by autoantibodies against coagulation factor VIII (FVIII). Immunosuppressive therapy for AHA aims to arrest bleeding by eliminating FVIII inhibitors. Factor VIII activity overshoot after complete remission (CR) has been reported anecdotally, but details remain unclear. We retrospectively analyzed data from 17 patients with AHA who achieved CR under immunosuppressive therapy between 2009 and 2019 at Gunma University Hospital. FVIII activity overshoot was defined as ≥ 150%. All 17 patients had low FVIII activity (median 2.1%; range < 1.0-8.9%) due to FVIII inhibition (median 14.7 BU/mL; range 2.0-234.0) and all achieved CR within a median of 39 (range 19-173) days. Overshoot occurred in 11 (64.7%) patients and maximal FVIII activity reached > 200% in six of them. The median duration from CR to overshoot was 13 (range 0-154) days. The FVIII overshoot was transient (72.7%) or persistent (27.3%). Venous thromboembolism developed as a complication of overshoot in one patient due to iliac vein compression by a massive hematoma. Overshoot of FVIII activity after CR occurs more frequently than previously expected in patients with AHA.

Long-term outcomes in the treatment of acquired hemophilia A: a 16-year single institution prospective cohort experience

: Acquired hemophilia A (AHA) is a rare bleeding disorder caused by autoantibodies against coagulation factor VIII. We conducted a single institution prospective cohort study to assess treatment strategies and long-term outcomes in AHA patients and provide further evidence for effective treatment and relapse timing. A total of 25 patients diagnosed with AHA between 2001 and 2017 at Penn State Hershey Medical Center were prospectively followed. Information was collected on factor VIII activity and inhibitor titer at diagnosis, treatment regimen(s), complete remission, and relapse time. For immunosuppressive therapy (IST), 19 patients were treated initially with prednisone and cyclophosphamide, four were treated with prednisone, one with prednisone and rituximab, and one with prednisone and second-line rituximab. 13/17 (76%) evaluable patients treated with prednisone and cyclophosphamide achieved complete remission. Four patients received rituximab as second-line therapy (inhibitor titers 34, 122, 416, and 768 BU); three achieved complete remission and one died from sepsis. Both evaluable patients receiving initial prednisone alone achieved complete remission. Five relapses occurred from 17 days to 7 years; all were treated with prednisone and cyclophosphamide and achieved complete remission. IST with prednisone and cyclophosphamide is highly effective in achieving and maintaining complete remission, even for relapsed patients. Despite dual IST with prednisone and cyclophosphamide, some patients, particularly with extremely high inhibitor titers, required addition of second-line rituximab to achieve complete remission. This supports rituximab as effective salvage treatment, including for patients with inhibitor titers at least 100-200 BU. Those who experienced relapse often did so years after complete remission, signifying importance of continued monitoring and vigilance.

Acquired hemophilia A

Acquired inhibitors of coagulation are a group of rare but potentially life-threatening blood disorders characterized by the presence of autoantibodies directed against clotting factor. Autoantibody against factor VIII is the most common form of clotting factor inhibitor, a condition also known as acquired hemophilia A. We present a clinical series of nine patients diagnosed and treated for acquired hemophilia A at our institution. Among these nine patients, there were five men and four women with a median age of 64 years. All patients presented with bleeding diathesis. Factor eight inhibitor bypassing agent and/or recombinant factor VIIa were predominantly used for control of active bleeding. For elimination of autoantibodies, either steroids alone or the combination of steroids with rituximab or oral cyclophosphamide was used. Despite aggressive measures, two of the patients had a poor outcome; seven of the nine patients (77%) had a good clinical outcome. Acquired hemophilia A should be strongly suspected in any patient presenting with bleeding and a prolonged activated partial thromboplastin time. Early initiation of factor bypassing agents such as activated prothrombin complex concentrates or recombinant factor VIIa, along with the use of immunosuppressive agents, can be lifesaving.

Targeting Acquired Hemophilia A with Rheumatoid Arthritis by a Rituximab Shot: A Case Report and Review of the Literature

Patient: Male, 66

Final Diagnosis: Acquired hemophilia A

Symptoms: Polyarticular flare

Medication: —

Clinical Procedure: —

Specialty: Rheumatology

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.

Frequency and epitope specificity of anti-factor VIII C1 domain antibodies in acquired and congenital hemophilia A

Several studies showed that neutralizing anti-factor VIII (anti-fVIII) antibodies (inhibitors) in patients with acquired hemophilia A (AHA) and congenital hemophilia A (HA) are primarily directed to the A2 and C2 domains. In this study, the frequency and epitope specificity of anti-C1 antibodies were analyzed in acquired and congenital hemophilia inhibitor patients (n = 178). The domain specificity of antibodies was studied by homolog-scanning mutagenesis (HSM) with single human domain human/porcine fVIII proteins and antibody binding to human A2, C1, and C2 domains presented as human serum albumin (HSA) fusion proteins. The analysis with HSA-fVIII domain proteins confirmed the results of the HSM approach but resulted in higher detection levels. The higher detection levels with HSA-fVIII domain proteins are a result of antibody cross-reactivity with human and porcine fVIII leading to false-negative HSM results. Overall, A2-, C1-, and C2-specific antibodies were detected in 23%, 78%, and 68% of patients with AHA (n = 115) and in 52%, 57%, and 81% of HA inhibitor patients (n = 63). Competitive binding of the human monoclonal antibody (mAb) LE2E9 revealed overlapping epitopes with murine C1-specific group A mAbs including 2A9. Mutational analyses identified distinct crucial binding residues for LE2E9 (E2066) and 2A9 (F2068) that are also recognized by anti-C1 antibodies present in patients with hemophilia. A strong contribution of LE2E9- and 2A9-like antibodies was particularly observed in patients with AHA. Overall, our study demonstrates that the C1 domain, in addition to the A2 and C2 domains, contributes significantly to the humoral anti-fVIII immune response in acquired and congenital hemophilia inhibitor patients.

Clinical characteristics and outcomes of acquired hemophilia A: experience at a single center in Japan

Acquired hemophilia A (AHA), which is caused by autoantibodies against coagulation factor VIII (FVIII) is a rare, life-threatening bleeding disorder, the incidence of which appears to be increasing in Japan as the population ages. However, the clinical characteristics, treatment, and outcomes of AHA remain difficult to establish due to the rarity of this disease. We retrospectively analyzed data from 25 patients (median age 73 years; range 24-92 years; male n = 15) diagnosed with AHA between 1999 and 2015 at Gunma University Hospital. We identified autoimmune diseases and malignancy as underlying conditions in four and three patients, respectively. Factor VIII activity was significantly decreased in all patients (median 2.0%; range <1.0-8.0) by FVIII inhibitor (median 47.0 BU/mL; range 2.0-1010). Among 71 bleeding events, subcutaneous or intramuscular hemorrhage was the most prevalent. Seventeen patients required bypassing agents. Twenty-two (91.7%) of 24 patients treated with immunosuppressive agents achieved complete response (CR) during a median of 57.5 days (range 19-714 days). Although three patients (12%) relapsed and seven (28%) died of infection, none of the deaths were related to bleeding. Although most of our patients achieved CR after immunosuppressive therapy, the rate of infection-related mortality was unsatisfactorily high.

Update on the use of immunoglobulin in human disease: A review of evidence

Human immunoglobulin preparations for intravenous or subcutaneous administration are the cornerstone of treatment in patients with primary immunodeficiency diseases affecting the humoral immune system. Intravenous preparations have a number of important uses in the treatment of other diseases in humans as well, some for which acceptable treatment alternatives do not exist. We provide an update of the evidence-based guideline on immunoglobulin therapy, last published in 2006. Given the potential risks and inherent scarcity of human immunoglobulin, careful consideration of its indications and administration is warranted.

Rituximab in the Treatment of Acquired Hemophilia

Objective:

To review published literature evaluating the use of rituximab for treatment of acquired hemophilia.

Data Sources:

An English-language literature search was conducted using MEDLINE (1966–January 2006). References of identified articles were subsequently reviewed for additional data. Search terms included rituximab, acquired hemophilia, and inhibitors.

Data Synthesis:

Available data suggest that B-cell depletion by rituximab in patients with acquired hemophilia may contribute to the eradication of inhibitors to coagulation factors. B-cells have been shown to be essential in the development of autoimmunity or an acquired immune response. Beneficial effects of rituximab, after failure of established therapies, have been reported in case reports and one small, open-label trial.

Conclusions:

Although data are limited, administration of rituximab appears to be an effective option for treatment of patients with acquired hemophilia after established therapies have failed. Patients given rituximab experienced cessation of recurrent bleeding, normalization of factor VIII activity, and eradication of inhibitors. A complete response to rituximab (undetectable inhibitors, normalization of factor levels) generally occurred several weeks to months after initiation of therapy.

Rituximab for eradicating inhibitors in people with acquired haemophilia A

BACKGROUND

Acquired haemophilia A is a rare bleeding disorder caused by the development of specific autoantibodies against coagulation factor VIII. Rituximab may be an alternative approach to the treatment of acquired haemophilia by eradicating FVIII autoantibodies.

OBJECTIVES

To assess and summarise the efficacy and adverse effects of rituximab for treating people with acquired haemophilia A.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's trials registers, comprising references identified from comprehensive electronic database searches and handsearches of relevant journals and conference proceedings.Date of last search of the Cochrane Cystic Fibrosis and Genetic Disorders Group's trials registers: 01 March 2016.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials of rituximab for people with acquired hemophilia A, with no restrictions on gender, age or ethnicity.

DATA COLLECTION AND ANALYSIS

No trials matching the selection criteria were eligible for inclusion.

MAIN RESULTS

No trials matching the selection criteria were eligible for inclusion.

AUTHORS' CONCLUSIONS

No randomised clinical trials of rituximab for acquired hemophilia A were found. Thus, based on the highest quality of evidence, we are not able to draw any conclusions or make any recommendations on rituximab for eradicating inhibitors in people with acquired haemophilia A. Given that undertaking randomised controlled trials in this field is a complex task, the authors suggest that, while planning such trials, clinicians treating the disease continue to base their choices on alternative, lower quality sources of evidence. The authors plan, for a future update of this review, to appraise and incorporate any randomised controlled trials, as well as other high-quality non-randomised studies.

Acquired Hemophilia: A Case Report of 2 Patients With Acquired Factor VIII Inhibitor Treated With Rituximab Plus a Short Course of Steroid and Review of the Literature

Acquired hemophilia is an unusual disorder in which nonhemophiliac patients develop autoantibodies (inhibitor) against the factor VIII coagulation protein. Factor VIII inhibitor leads to life-threatening bleeding disorders classically described as new onset of diffuse bruising and prolonged partial thromboplastin time in elderly patients. Treatment is focused in the control of the acute bleeding episode and the long-term suppression of the autoantibody. Several immunosuppressive combinations have been described; however, these treatments are also associated with serious side effects that are difficult to tolerate, especially in older and debilitated patients. New treatment modalities explore the elimination of the autoantibody production by targeting B-cells with rituximab, an anti CD-20 monoclonal antibody that has shown success in a multitude of autoimmune processes. This report presents 2 patients successfully treated with rituximab and a short tapering course of steroids and focuses our discussion in the analysis of different treatment approaches available for these patients' population.

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

[Two elderly patients with difficult-to-treat acquired hemophilia A]

We herein report the cases of two elderly patients with acquired hemophilia A (AHA) for whom treatment was difficult.An 89-year-old woman (Case 1) was admitted to our department with subcutaneous hemorrhage and melena. Her activated partial thromboplastin time (APTT), factor VIII activity, and factor VIII inhibitor level were 127.7 seconds, 1.0%, and 48 BU/mL, respectively, which was suggestive of AHA. The administration of prednisolone (PSL 0.5 mg/kg) was initiated. After 3 weeks, PSL was combined with cyclophosphamide (CPA 50 mg). Two months after the start of treatment, her factor VIII inhibitor level decreased to 3.4 BU/mL. However, hemorrhagic signs were repeatedly observed during the discontinuation of recombinant activated factor VII (rFVIIa) preparation; bleeding control became insufficient, and pneumonia developed, thus leading to a fatal outcome.An 81-year-old woman (Case 2) was admitted to our department with subcutaneous hemorrhage, anemia (Hb: 9.2 g/dL), and a prolonged APTT (78.7 seconds). Her factor VIII activity was reduced to 0.9%, and her factor VIII inhibitor level was markedly increased to 1,364.9 BU/mL, suggesting AHA. Treatment with PSL (0.5 mg/kg) was initiated. After one month, it was combined with CPA (50 mg); however, her hemorrhagic signs were protracted, and her Hb level decreased to 8.0 g/dL. Subsequently, pneumonia occurred. However, weekly rituximab therapy (375 mg/m2) for 4 weeks decreased her factor VIII inhibitor level, leading to the disappearance of the inhibitor at 1 year and 5 months. During this period, there were no episodes requiring the administration of bypassing agents, such as rFVIIa.

Acquired hemophilia A in the HIV-infected patient: a case report and literature review

Acquired hemophilia A is a rare bleeding disorder caused by autoantibodies against factor VIII (FVIII). Spontaneous bleeding in the various sites and severity is the most common clinical presentation. Here, we report a 74-year-old Thai woman with HIV infection who presented with spontaneous ecchymoses. The laboratory revealed isolated activated partial thromboplastin time prolongation with low FVIII activity and a presence of FVIII inhibitor. She was diagnosed with acquired hemophilia A. Corticosteroid monotherapy was the treatment regimen for inhibitor eradication. We demonstrate the clinical course of the rare condition and review the relevant literature.

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 case report and review of the literature

Acquired hemophilia A (AHA) is a rare bleeding disorder caused by autoantibodies against clotting factor VIII (FVIII). FVIII autoantibody is characterized as polyclonal immunoglobulin G directed against the FVIII procoagulant activity. This disease occurs most commonly in the elderly population and with preponderance of men in nonpregnancy-related AHA. There are well-established clinical associations with AHA such as malignancy, other autoimmune diseases and pregnancy. However, up to 50% of reported cases remain idiopathic. The clinical manifestation of AHA includes mostly spontaneous hemorrhages into skin, muscles and soft tissues, or mucous membranes. AHA should be suspected when a patient with no previous history of bleeding presents with bleeding and an unexplained prolonged activated partial thromboplastin time. The diagnosis is confirmed in the laboratory by the subsequent identification of reduced FVIII levels and FVIII inhibitor titration. There is a high mortality, making prompt diagnosis and treatment vitally important. The principles of treatment consist in controlling the bleeding and eradicating the inhibitor. Because of the overall high relapse rate (15-33%), it is also recommended to follow up these patients. The review summarizes what is currently known about the epidemiology, pathogenesis, clinical features, diagnosis, treatment and prognosis of AHA and starts with a case report.

Inhibitor eradication with rituximab in haemophilia: where do we stand?

Rituximab is a humanized chimeric anti-CD20 monoclonal antibody initially developed for the treatment of some haematological malignancies. Thanks to its ability to rapidly and specifically deplete B cells, it has also been used in a variety of autoimmune disorders, haematological or not. In this context, during the last decade several small case series have documented successful inhibitor eradication with rituximab, alone or in combination with other immunosuppressive agents, in patients with acquired haemophilia A refractory to standard therapy. In addition, a number of investigators have recently used this agent in patients with congenital haemophilia A or B and alloantibodies refractory to first-line treatment. This article critically reviews the current knowledge on the use of rituximab in acquired haemophilia or congenital haemophilia complicated by alloantibodies, also providing treatment algorithms for the management of these conditions.

Perioperative management of acquired hemophilia a: a case report and review of literature

Introduction:

Acquired hemophilia A is a rare bleeding disorder with a high mortality rate. Diagnosis and treatment of this disorder can be very challenging to anesthesiologists because of lack of a personal or familial abnormal bleeding history.

Case presentation:

We report a 60-year-old woman who presented to the operating room for an urgent fasciotomy. She was initially diagnosed to have compartment syndrome of her left upper extremity secondary to an expanding hematoma after multiple unsuccessful venipuncture attempts. After surgical intervention, she developed recurrent intramuscular hematomas, became severely anemic, and required surgical re-exploration and multiple blood product transfusions. Ultimately, she was found to have an elevated activated partial thromboplastin time (aPTT), very low FVIII activity, and high FVIII inhibitor titers consistent with the diagnosis of acquired hemophilia A.

Conclusions:

Treatment strategies in acquired hemophilia are based on two major objectives. During the acute stage, effective control of bleeding is critical. The ultimate therapeutic goal during the subacute phase is the elimination of the inhibitors targeting factor VIII. Here, we present this case and will review current literature regarding therapeutic approaches to this rare condition in the operating room setting and postoperative course.

Acquired factor XIII deficiency: a therapeutic challenge

Less than 60 cases of acquired factor (F)XIII deficiencies have been reported, most having distinct clinical features. To illustrate the therapeutic challenges of acquired FXIII inhibitors, we report a case of a 65-year-old patient with no previous bleeding history who suddenly developed massive haemorrhages associated to a strong and isolated FXIII inhibitor. No underlying disorder has been detected till now after three years of follow-up. Despite aggressive treatment with prednisone, rituximab, cyclophosphamide, immunoglobulin, immunoadsorption and immune tolerance his inhibitor is still present, although at low titre and with a clinical benefit since the patient has no more bleed since more than one year. Moreover the patient had a venous thromboembolic complication. After a review of the management of acquired FXIII deficiency patients and based on the management of acquired haemophilia we discuss a possible strategy for such difficult cases.

Extracorporeal Treatment for the Acute und Long-Term Outcome of Patients with Life-Threatening Acquired Hemophilia

OBJECTIVES: In acquired hemophilia (AH), autoantibodies (inhibitors) impede blood coagulation factors leading to severe bleedings. Cornerstones of a successful treatment are the control of bleeding and an eradication of autoantibodies. The present study is an update of our previous documentation of the treatment of high-titer AH patients with severe life-threatening bleeding undergoing the modified Bonn-Malmö-Protocol (MBMP). METHODS: 64 AH patients were treated by a standard combination protocol (MBMP) consisting of antibody depletion through immunoadsorption, i.v. immunoglobulin, immunosuppression, and high-dose FVIII substitution. They underwent a long-term follow-up. RESULTS: Primary study endpoints loss of detection of the activity of the inhibitor and FVIII recovery ? 5% were reached in a median time of 3 days (95% CI: 2.6-3.4 days), the median time of FVIII substitution was 13 days (95% CI 10.6-15.3 days), and the median time of immunoadsorption was 16 days (95% CI 13-18.9 days). In 5 patients the AH occurred as paraneoplastic syndrome, and partial remission was achieved. Relapses without bleeding event occurred only in second-line MBMP. Those responded excellently to short time treatment. Overall patients remained in remission over a median follow-up time of 8 years. Conclusion: Except for paraneoplastic AH, MBMP-treated patients have a remarkable prognosis which is confirmed by long-term follow-up with a complete response rate of 93% (53/57) in the first year post MBMP and 100% during long-term follow-up. These outcome in life-threatening AH is unique and until now not achievable via other treatment schedules. In life-threatening bleedings physicians should take into account MBMP as a first line treatment.

Pharmacological modulation of humoral immunity in a nonhuman primate model of AAV gene transfer for hemophilia B

Liver gene transfer for hemophilia B has shown very promising results in recent clinical studies. A potential complication of gene-based treatments for hemophilia and other inherited disorders, however, is the development of neutralizing antibodies (NAb) against the therapeutic transgene. The risk of developing NAb to the coagulation factor IX (F.IX) transgene product following adeno-associated virus (AAV)-mediated hepatic gene transfer for hemophilia is small but not absent, as formation of inhibitory antibodies to F.IX is observed in experimental animals following liver gene transfer. Thus, strategies to modulate antitransgene NAb responses are needed. Here, we used the anti-B cell monoclonal antibody rituximab (rtx) in combination with cyclosporine A (CsA) to eradicate anti-human F.IX NAb in rhesus macaques previously injected intravenously with AAV8 vectors expressing human F.IX. A short course of immunosuppression (IS) resulted in eradication of anti-F.IX NAb with restoration of plasma F.IX transgene product detection. In one animal, following IS anti-AAV6 antibodies also dropped below detection, allowing for successful AAV vector readministration and resulting in high levels (60% or normal) of F.IX transgene product in plasma. Though the number of animals is small, this study supports for the safety and efficacy of B cell-targeting therapies to eradicate NAb developed following AAV-mediated gene transfer.

Immunosuppression for acquired hemophilia A: results from the European Acquired Haemophilia Registry (EACH2)

Acquired hemophilia A (AHA) is an autoimmune disease caused by an autoantibody to factor VIII. Patients are at risk of severe and fatal hemorrhage until the inhibitor is eradicated, and guidelines recommend immunosuppression as soon as the diagnosis has been made. The optimal immunosuppressive regimen is unclear; therefore, data from 331 patients entered into the prospective EACH2 registry were analyzed. Steroids combined with cyclophosphamide resulted in more stable complete remission (70%), defined as inhibitor undetectable, factor VIII more than 70 IU/dL and immunosuppression stopped, than steroids alone (48%) or rituximab-based regimens (59%). Propensity score-matched analysis controlling for age, sex, factor VIII level, inhibitor titer, and underlying etiology confirmed that stable remission was more likely with steroids and cyclophosphamide than steroids alone (odds ratio = 3.25; 95% CI, 1.51-6.96; P < .003). The median time to complete remission was approximately 5 weeks for steroids with or without cyclophosphamide; rituximab-based regimens required approximately twice as long. Immunoglobulin administration did not improve outcome. Second-line therapy was successful in approximately 60% of cases that failed first-line therapy. Outcome was not affected by the choice of first-line therapy. The likelihood of achieving stable remission was not affected by underlying etiology but was influenced by the presenting inhibitor titer and FVIII level.

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.

Efficacy of low-dose rituximab in a refractory acquired factor VIII inhibitor case secondary to pemphigus

Acquired factor VIII (FVIII) inhibitor induces a bleeding disorder caused by specific antibodies to FVIII. The cause of approximately one fifth of cases can be attributed to autoimmune disorders, such as pemphigus. Here, we describe a case of refractory acquired FVIII inhibitor in a patient with primary pemphigus and its successful treatment with low-dose rituximab. Coagulation studies revealed a prolonged activated partial thromboplastin time, which could not be corrected with the mixing test. At the same time, the FVIII activity level was significantly reduced, and the FVIII inhibitor titer was elevated. A treatment regimen with prednisolone/cyclophosphamide followed by prednisolone/cyclosporine was used. The patient temporarily responded but then became resistant to these medicines. However, subsequent treatment with low-dose rituximab achieved considerable clinical and laboratory improvement in the same patient. Follow-up at 6 months revealed a low level of residual FVIII inhibitor activity with normal coagulation functions. No drug-related side effects were detected. In conclusion, our results indicate that low-dose rituximab might be an effective and safe treatment for patients with acquired FVIII inhibitor.

Case report of an acquired factor XIII inhibitor: diagnosis and management

A 57-year-old man presented with a spontaneous upper-extremity hematoma and compartment syndrome. The patient experienced excessive bleeding following evacuation of the hematoma, and the results of routine coagulation studies were normal. Factor XIII activity was undetectable using a photometric assay, and the presence of an inhibitor was detected with mixing studies. Bleeding was controlled with infusions of fresh frozen plasma and cryoprecipitate. Cyclophosphamide was started on the 16th hospital day, and four weekly doses of the monoclonal anti-CD20 antibody, rituximab, were begun 3 weeks later. One week after the initial dose of rituximab, the inhibitor was no longer detectable and the factor XIII level increased to 28%. After completion of the rituximab therapy, the factor XIII activity was 58% with no inhibitor present. This case illustrates the need to check for unusual defects such as factor XIII deficiency if a bleeding tendency is evident-even if routine studies are unrevealing.

Acquired von Willebrand syndrome associated with monoclonal gammopathy: a single-center study of 36 patients

In this single-center retrospective study, we evaluated the accuracy of laboratory tests in diagnosing acquired von Willebrand syndrome associated with lymphoproliferative disorders in 36 consecutive patients diagnosed at the University Hospital of Nantes, France. We also compared hemostatic treatments in the following groups: 21 patients with Waldenström macroglobulinemia (WM), 14 with monoclonal gammopathy of undetermined significance (MGUS) (10 with IgG-MGUS and 4 with IgM-MGUS), and 1 with IgA multiple myeloma (IgA-MM). The diagnosis was made in 18 (50%) patients during systematic screening, in 6 (17%) during active mild hemorrhage, and in 12 (33%) during an active, severe bleed. Of the laboratory tests studied, only closure times measured on the Platelet Function Analyzer (PFA)-100 device reliably diagnosed the hemostatic problem. There was no relationship between the factor VIII activity (FVIII:C) or von Willebrand factor activity (VWF:RCo) levels and the previous history of hemorrhage described by patients.We studied hemostatic treatment in most patients: IgG-MGUS patients responded well to high-dose intravenous immunoglobulin (IVIg) infusions (1 g/kg per d), although patients with IgM-MGUS did not. Desmopressin infusions were effective in 3 patients with IgG-MGUS and 2 patients with IgM-MGUS when the baseline values were above 10 IU/dL, but levels soon returned to the baseline. The 7 WM patients had a good response to desmopressin. These results confirm the efficacy of IVIg in IgG-MGUS patients and the prominent role of closure time in the diagnosis of acquired von Willebrand syndrome.

Inhibitors of propagation of coagulation (factors VIII, IX and XI): a review of current therapeutic practice

The management of patients with congenital haemophilia who develop alloantibodies against factors of the propagation phase of blood coagulation, commonly known as inhibitors, is the most important challenge facing haemophilia caregivers at present, as this complication not only compromises the efficacy of replacement therapy but also consumes an enormous amount of economic resources. Development of inhibitors further complicates the clinical course of severe haemophilia, with a prevalence of up to 30% in patients with haemophilia A (factor VIII deficiency) and up to 5% in those with haemophilia B (factor IX deficiency) and haemophilia C (factor XI deficiency). While the short-term goal of treatment of patients who develop alloantibodies is the control of bleeding, the eradication of the inhibitor is the main long-term goal. The management of severe bleeding episodes and the eradication of the autoantibody are also the mainstays of treatment of patients with acquired haemophilia, a rare but life-threatening haemorrhagic condition characterized by the development of inhibitory autoantibodies against coagulation factor VIII. The most recent options available for treating patients with congenital haemophilia complicated by inhibitors and acquired haemophilia because of autoantibodies against factor VIII are summarized in this review article.