Rituximab in the treatment of acquired factor VIII inhibitors

Acquired haemophilia as a complicating factor in treatment of non-muscle invasive bladder cancer: A case report

BACKGROUND

Acquired haemophilia (AH) is a serious autoimmune haematological disease caused by the production of auto-antibodies against coagulation factor VIII. In some patients, AH is associated with a concomitant malignancy. In case of surgical intervention, AH poses a high risk of life-threatening bleeding.

CASE SUMMARY

A 60-year-old female patient with multiple recurrences of non-muscle invasive bladder cancer underwent transurethral tumour resection. A severe haematuria developed postoperatively warranting two endoscopic revisions; however, no clear source of bleeding was identified in the bladder. Subsequent haematological examination established a diagnosis of AH. Treatment with factor VIII inhibitor bypass activity and immunosuppressive therapy was initiated immediately. The patient responded well to the therapy and was discharged from the hospital 21 d after the primary surgery. At the 38-mo follow-up, both AH and bladder cancer remained in complete remission.

CONCLUSION

AH is a rare, life-threatening haematological disease. AH should be considered in patients with persistent severe haematuria or other bleeding symptoms, especially if combined with isolated activated partial thromboplastin time prolongation.

Acquired haemophilia as a complicating factor in treatment of non-muscle invasive bladder cancer: A case report

BACKGROUND

Acquired haemophilia (AH) is a serious autoimmune haematological disease caused by the production of auto-antibodies against coagulation factor VIII. In some patients, AH is associated with a concomitant malignancy. In case of surgical intervention, AH poses a high risk of life-threatening bleeding.

CASE SUMMARY

A 60-year-old female patient with multiple recurrences of non-muscle invasive bladder cancer underwent transurethral tumour resection. A severe haematuria developed postoperatively warranting two endoscopic revisions; however, no clear source of bleeding was identified in the bladder. Subsequent haematological examination established a diagnosis of AH. Treatment with factor VIII inhibitor bypass activity and immunosuppressive therapy was initiated immediately. The patient responded well to the therapy and was discharged from the hospital 21 d after the primary surgery. At the 38-mo follow-up, both AH and bladder cancer remained in complete remission.

CONCLUSION

AH is a rare, life-threatening haematological disease. AH should be considered in patients with persistent severe haematuria or other bleeding symptoms, especially if combined with isolated activated partial thromboplastin time prolongation.

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.

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 Hemophilia A Presenting as Massive Postoperative Bleeding in a Patient with Oral Squamous Cell Carcinoma

Acquired hemophilia A (AHA) is an extremely rare and serious bleeding disorder caused by autoantibodies against coagulation factor VIII (FVIII). Approximately, 10% of patients with AHA have an underlying malignancy. We report on a 46-year-old man with AHA and advanced oral cancer who presented with massive bleeding after surgery. Preoperative blood coagulation tests showed no abnormalities. He underwent radical tumor resection followed by reconstruction using a free rectus abdominal musculocutaneous flap. Massive subcutaneous hemorrhage developed in his neck and abdomen on the first postoperative day. The hemorrhage remained uncontrolled, despite embolization of the responsible vessels. Subsequent laboratory data showed prolonged activated partial thromboplastin time and decreased FVIII levels. On the basis of his clinical course and the presence of the FVIII inhibitor, we speculated that the patient suffered from AHA. We administered recombinant activated factor VII and prednisolone, after which the spontaneous bleeding stopped and the subcutaneous hemorrhage resolved. A review of the literature identified only three previous documented cases of AHA associated with head and neck cancer. This case indicates that AHA should not be ruled out in patients with uncontrolled postoperative bleeding, while attempting to ensure bleeding control and preventing potentially catastrophic fatal consequences.

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 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.

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.

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.

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.

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.

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.

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.

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.

The first case of postpartum acquired hemophilia A in Korea

Acquired hemophilia A (AHA) is a rare coagulopathy caused by autoantibodies to coagulation factor VIII (FVIII). Most patients with AHA have been previously healthy; however, a variety of morbidities have been associated with the condition including pregnancy. A 40-yr-old woman visited our institution with extensive hematoma on the right hip area. Her medical history revealed no personal or familial history of bleeding diathesis. Her coagulation tests showed markedly prolonged aPTT (117 sec), markedly decreased level of FVIII activity (0.4%) and high-titer FVIII inhibitor (77 BU). Collectively, she was diagnosed as having postpartum AHA and was treated with bypassing agents and corticosteroids. Her aPTT was normalized on the 174 th postpartum day and FVIII inhibitor showed negative conversion on the 224 th postpartum day. This is the first case of postpartum AHA with high-titer FVIII inhibitor in Korea. Timely diagnosis and management can reduce morbidity and mortality of this potentially life-threatening condition.

Anti-CD20 monoclonal antibodies and their use in adult autoimmune hematological disorders

Autoimmune hematological disorders encompass a broad group of hematological conditions characterized by the loss of self-tolerance to a variety of antigens. Despite good response to first-line therapy in the majority of patients, relapses are common, necessitating new and safe therapeutic options. The anti-CD20 monoclonal antibody rituximab has led to substantial improvement in the treatment of malignant and immune-mediated disorders involving B cells. Although experience with rituximab in immune-mediated hematological disorders is rarely supported by randomized trials, there is now substantial experience with rituximab suggesting that anti-CD20 therapy is an effective and well-tolerated alternative to immunosuppressive therapy in these disorders. However, caution is needed based on recent reports describing-sometimes severe-rituximab-related complications.

Acquired hemophilia a: diagnosis, aetiology, clinical spectrum and treatment options

Acquired hemophilia A (AHA) is a rare disorder with an incidence of approximately 1 per million/year with a high mortality rate of more than 20%. The disease occurs due to autoantibodies against coagulation factor VIII (FVIII) which neutralize its procoagulant function and result in severe, often life-threatening bleeding. The antibodies arise in individuals with no prior history of hemophilia A. AHA may be associated with pregnancy, autoimmune diseases, malignancy, infections or medication and occurs most commonly in the elderly. Approximately 50% of the patients remain idiopathic with no known underlying pathological condition. Clinical manifestations include spontaneous hemorrhages into the skin, muscles or soft tissues or excessive bleeding during surgery. Hemarthrosis which is the hallmark of congenital severe hemophilia A seldom occurs in AHA. The diagnosis of AHA is based on the isolated prolongation of activated partial thromboplastin time (APTT) which does not normalize after the addition of normal plasma along with reduced FVIII levels. The treatment involves two aspects-eradication of antibodies and maintaining effective hemostasis during a bleeding episode. The protocols for eradication of antibodies include immunoadsorption, immunosuppression or immune tolerance induction (ITI). The treatment of acute bleeding episodes involves use of different bypassing agents like recombinant activated factor VIIa (rFVIIa, NovoSeven®) and activated prothrombin complex concentrate (aPCC, (FEIBA®) in case of patients with high titer inhibitors or with antifibrinolytics,1-deamino-8-D-arginine vasopressin (DDAVP) or FVIII concentrates in low titer inhibitor patients. The anti CD20 monoclonal antibody, rituximab, has shown very good results either singly or in combination with immunosuppressive regimens in patients who do not respond to standard immunosuppressors. The present review summarizes the diagnostic, aetiological, clinical and treatment aspects of AHA focusing on the recent advances in this area.

The prognosis and treatment of acquired hemophilia: a systematic review and meta-analysis. Blood Coagul Fibrinolysis. 2009;20:517-523. [PMID: 19644360 DOI: 10.1097/mbc.0b013e32832ca388]

The inhibition of factor VIII by autoantibody development, or acquired hemophilia, occurs in approximately one person per million each year and can cause life-threatening bleeding. Due to the disease rarity, there are no randomized studies addressing prognostic features and treatment. The goal of this study is to identify prognostic indictors in acquired hemophilia to guide treatment choices. MEDLINE and EMBASE search from 1985-2008 retrieved 32 studies with detailed clinical information on five or more patients with acquired hemophilia. Univariate and multivariate analysis of the effects of age, sex, underlying condition, inhibitor titer, and treatment regimen were evaluated with regards to complete remission and death. A total of 32 studies containing 359 patients with acquired hemophilia were included in the analysis. The all-cause mortality rate in this cohort was 21%. Multivariate analyses revealed that patients more likely to die are the elderly [odds ratio (OR) 2.4, 95% confidence interval (CI) 1.32-4.36] and those with underlying malignancy (OR 2.76, CI 1.38-5.50). Early achievement of complete remission resulted in improved survival. Complete remission occurred in 94% of patients receiving combination chemotherapy, 82% receiving dual therapy, and 68% receiving steroids alone. Patients receiving immunosuppression had reduced odds of persistent hemophilia, with combination chemotherapy being the most efficacious (OR 0.04, CI 0.01-0.23) and steroid therapy alone being the least (OR 0.38, CI 0.14-0.94). In acquired hemophilia, increased age, underlying malignancy, and lack of complete remission are risk factors for death. Although the included studies were not randomized, patients treated with combination chemotherapy had the greatest odds of remission and the lowest odds of death.

Consensus recommendations for the diagnosis and treatment of acquired hemophilia A

BACKGROUND

Acquired hemophilia A (AHA) is a rare bleeding disorder caused by an autoantibody to coagulation factor (F) VIII. It is characterized by soft tissue bleeding in patients without a personal or family history of bleeding. Bleeding is variable, ranging from acute, life-threatening hemorrhage, with 9-22% mortality, to mild bleeding that requires no treatment. AHA usually presents to clinicians without prior experience of the disease, therefore diagnosis is frequently delayed and bleeds under treated.

METHODS

Structured literature searches were used to support expert opinion in the development of recommendations for the management of patients with AHA.

RESULTS

Immediate consultation with a hemophilia center experienced in the management of inhibitors is essential to ensure accurate diagnosis and appropriate treatment. The laboratory finding of prolonged activated partial thromboplastin time with normal prothrombin time is typical of AHA, and the diagnosis should be considered even in the absence of bleeding. The FVIII level and autoantibody titer are not reliable predictors of bleeding risk or response to treatment. Most patients with AHA are elderly; comorbidities and underlying conditions found in 50% of patients often influence the clinical picture. Initial treatment involves the control of acute bleeding with bypassing agents. Immunosuppressive treatment to eradicate the FVIII inhibitor should be started as soon as the diagnosis is confirmed to reduce the time the patient is at risk of bleeding.

CONCLUSIONS

These recommendations aim to increase awareness of this disorder among clinicians in a wide range of specialties and provide practical advice on diagnosis and treatment.

Advances in the understanding of acquired haemophilia A: implications for clinical practice

Acquired haemophilia A is an auto-immune disease caused by an inhibitory antibody to factor VIII. Patients with an acquired factor VIII inhibitor are at risk of life- and limb-threatening bleeding until the inhibitor has been eradicated. Management relies on rapid and accurate diagnosis, control of bleeding episodes, investigation for a precipitating cause and eradication of the inhibitor by immunosuppression. Patients should always be managed jointly with a specialist centre even if they present without overt bleeding. Despite an extensive literature, few controlled data are available and management guidelines are predominantly based on case reports, retrospective cohorts and expert opinion. This paper reviews the current literature on incidence, pathogenesis, diagnosis, haemostatic therapy and inhibitor eradication strategies. Potential future developments are discussed.

Rituximab in the treatment of adult acquired hemophilia A: A systematic review

Rituximab is a monoclonal chimeric antibody to the CD20 antigen, which has proven to be effective in the treatment of non-Hodgkin lymphomas. Recently, rituximab has also been employed in many non-malignant autoimmune disorders (i.e., idiopathic thrombocytopenic purpura, thrombotic thrombocytopenic purpura, connective tissue disorders and autoimmune hemolytic anemia) in which it has been used with the aim of interfering with the production of pathologic antibodies. Moreover, this agent has also shown to be effective in the treatment of acquired antibodies against factor VIII. Through a careful literature search, the current knowledge on rituximab therapy in adult acquired hemophilia A is presented in this review. Although mostly based on uncontrolled studies, the literature data suggest that this drug can be useful in the treatment of disorders of acquired inhibitors to factor VIII. However, large, prospective, randomized trials are needed to confirm these positive preliminary results.