Rituximab for autoimmune haemophilia: a proposed treatment algorithm

Synthesis and evaluation of catecholamine derivatives as amyloid-beta aggregation inhibitors

Effectively inhibition of amyloid β (Aβ) aggregation is considered an important method for treatment of the Alzheimer's disease. Herein, inspired by the ability of trans-clovamide to effectively inhibit Aβ aggregation, we synthesized a series of structurally related catecholamine derivatives and tested them as Aβ aggregation inhibitors using the Thioflavin T assay. The results show that they demonstrated a higher inhibitory rate against Aβ aggregation. Furthermore, these compounds exhibited high water solubilities and low cytotoxicities. Additionally, transmission electron microscopy images and dynamic light scattering of their Aβ aggregations were observed. Docking simulations revealed that the catechol moiety of the synthesized compounds can form hydrogen bonds with the key regions of Aβ and thereby inhibit Aβ aggregation.

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.

Surgery-associated acquired hemophilia A: a report of 2 cases and review of literature

BACKGROUND

Acquired Hemophilia A (AHA) is a rare bleeding diathesis in patients with no previous personal or family bleeding history. The diagnosis of this disease often delays due to unfamiliarity of physicians with it, which leads to its high mortality rate.

CASE PRESENTATION

Two cases (one 12 years old female and another 18 years old male) were admitted for right upper abdominal mass and right upper abdominal pain respectively at different times. Pre-operative diagnosis of both cases was congenital choledochal cyst. They suffered continuous gastrointestinal bleeding (hematemesis and melena) with reduced hemoglobin to 54 g/L and 60 g/L after Roux-en-Y anastomosis respectively. To investigate the exact bleeding site, Digital subtraction angiography (DSA) of case 1 showed contrast overflow at small branch of proper hepatic artery but had unremarkable result for case 2, whereas gastroscopy of both cases showed unremarkable results. Multiple surgeries were also performed for hemostatic purpose but each time no active bleeding site was found. Finally, hematologists consultation was mandated in both cases and they were diagnosed as acquired haemophilia A. However, unfortunately case 1 patient could not survive because of sever hemorrhage and infection while Case 2 of 18 years old male survived after proper haemophilia treatment catalog.

CONCLUSION

Awareness about surgery associated acquired haemophilia A (SAHA) can facilitate quick diagnosis and lifesaving management because the mortality rate in SAHA is high due to lake of knowledge or late recognition of the disease. Bleeding always occurs at surgical sites and it can occur immediately within few hours after surgery in some cases. Hemorrhage may be severe or even life threatening and it presents a special challenge for diagnosis and treatment in a patient who has just undergone a surgical procedure. The treatment strategies for AHA include resumption of hemostasis with either recombinant porcine factor VIII (rpFVIII) or bypassing agents and immunosuppressive therapy to suppress the production of the factor VIII inhibitor.

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.

Therapeutic plasma exchange as part of multimodal treatment of acquired hemophilia in a patient with concurrent acute intracerebral bleed and pulmonary embolism

BACKGROUND

Autoantibodies against Factor VIII (FVIII) define the rare but life-threatening bleeding disorder acquired hemophilia A (AHA). Correction of FVIII deficiency and eradication of the factor inhibitor are the ultimate therapeutic goals in this disorder. Bypassing agents such as recombinant factor VIIa (rFVIIa) or FVIII inhibitor bypassing agent are often used to control coagulopathy before the inhibitor is eradicated. Bypassing agents carry a risk of thrombosis, however.

CASE REPORT

We report a patient with newly diagnosed AHA and thalamic bleed who additionally had active atrial fibrillation and developed a segmental pulmonary embolism, limiting tolerable rFVIIa dosage. This patient with very-high-risk brain bleed and concurrent thrombosis on bypass agent represented a significant management dilemma for which we successfully utilized therapeutic plasma exchange (TPE) to reduce the inhibitor titer.

RESULTS

FVIII inhibitor was undetectable and FVIII level was above the lower limit of normal within 12.5 days from starting TPE. While the patient ultimately died 24 days from admission for reasons unrelated to bleeding, his intracerebral hemorrhage was unchanged in size and no other bleeding morbidity was observed.

CONCLUSION

This patient achieved eradication of FVIII inhibitor and did not have bleed expansion while receiving multimodal therapy including corticosteroids, rituximab, and TPE. We discuss the periprocedural risks of TPE in an acquired hemophilia patient and our multiteam management of that risk.

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.

Preparation study of indocyanine green-rituximab: A new receptor-targeted tracer for sentinel lymph node in breast cancer

An appropriate receptor-targeted tracer for sentinel lymph node biopsy (SLNB) was prepared. We combined the fluorescence tracer (Indocyanine green, ICG) with Rituximab (a chimeric human/murine monoclonal antibody targeting the CD20 antigen on the surface of lymphocyte) directly to produce a new tracer (ICG-Rituximab). When the new tracer drains to the lymph node, Rituximab will combine with CD20 receptor on the B-cell surface in the lymph node. If the statue of antibody-receptor connection does not reach saturation, the number of Rituximab is less than CD20. With this appropriate injection dose, the new tracer could only stay in sentinel lymph node (SLN) and make it imaging. Positive fluorescence SLN was detected 12 minutes after injection with no other organs imaging. The imaging of SLN was stable and clear for 20-24 hours. Due to SLN stained with more ICG than the lymphatic vessel, the fluorescence situation of SLN would be brighter than the vessel. The surgeon can detect the positive fluorescence SLN easily without following the fluorescence imaging lymphatic vessel. The results of our preliminary study showed that the new tracer might be useful for improving SLN imaging and worth further clinical study. SLNB with the new tracer could be a convenient method for detecting SLN and would become a standard performance in clinical practice.

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.

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.

Cell-specific uptake of mantle cell lymphoma-derived exosomes by malignant and non-malignant B-lymphocytes

Mantle cell lymphoma (MCL) is an aggressive and incurable mature B cell neoplasm. The current treatments are based on chemotherapeutics and new class of drugs (e.g. Ibrutinib(®)), which in most cases ends with tumor resistance and relapse. Therefore, further development of novel therapeutic modalities is needed. Exosomes are natural extracellular vesicles, which play an important role in intercellular communication. The specificity of exosome uptake by different target cells remains unknown. In this study, we observed that MCL exosomes are taken up rapidly and preferentially by MCL cells. Only a minor fraction of exosomes was internalized into T-cell leukemia and bone marrow stroma cell lines, when these cells were co-cultured with MCL cells. Moreover, MCL patients' exosomes were taken up by both healthy and patients' B-lymphocytes with no apparent internalization to T lymphocytes and NK cells. Exosome internalization was not inhibited by specific siRNA against caveolin1 and clathrin but was found to be mediated by a cholesterol-dependent pathway. These findings demonstrate natural specificity of exosomes to B-lymphocytes and ultimately might be used for therapeutic intervention in B cells malignancies.

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.

Anti-CD20 as the B-Cell Targeting Agent in a Combined Therapy to Modulate Anti-Factor VIII Immune Responses in Hemophilia a Inhibitor Mice

Neutralizing antibody formation against transgene products can represent a major complication following gene therapy with treatment of genetic diseases, such as hemophilia A. Although successful approaches have been developed to prevent the formation of anti-factor VIII (FVIII) antibodies, innovative strategies to overcome pre-existing anti-FVIII immune responses in FVIII-primed subjects are still lacking. Anti-FVIII neutralizing antibodies circulate for long periods in part due to persistence of memory B-cells. Anti-CD20 targets a variety of B-cells (pre-B-cells to mature/memory cells); therefore, we investigated the impact of B-cell depletion on anti-FVIII immune responses in hemophilia A mice using anti-CD20 combined with regulatory T (Treg) cell expansion using IL-2/IL-2mAb complexes plus rapamycin. We found that anti-CD20 alone can partially modulate anti-FVIII immune responses in both unprimed and FVIII-primed hemophilia A mice. Moreover, in mice treated with anti-CD20+IL-2/IL-2mAb complexes+rapamycin+FVIII, anti-FVIII antibody titers were significantly reduced in comparison to mice treated with regimens targeting only B or T cells. In addition, titers remained low after a second challenge with FVIII plasmid. Treg cells and activation markers were transiently and significantly increased in the groups treated with IL-2/IL-2mAb complexes; however, significant B-cell depletion was obtained in anti-CD20-treated groups. Importantly, both FVIII-specific antibody-secreting cells and memory B-cells were significantly reduced in mice treated with combination therapy. This study demonstrates that a combination regimen is highly promising as a treatment option for modulating anti-FVIII antibodies and facilitating induction of long-term tolerance to FVIII in hemophilia A mice.

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.

Therapeutic challenges in acquired factor VIII deficiency

Management of acquired hemophilia A is challenging and should be undertaken in close collaboration with a hemophilia center with expertise in the field. Treatment involves controlling and preventing bleeds and using immunosuppression to eradicate the inhibitor. Prompt diagnosis is important to allow early hemostatic treatment and to prevent nonessential invasive procedures. First-line hemostatic treatment should be with a bypassing agent. Recombinant activated factor VII and the activated prothrombin complex concentrate anti-inhibitor coagulant complex (Factor Eight Inhibitor Bypassing Activity, or FEIBA) but equally efficacious but both associated with thrombotic events when used in acquired hemophilia. Immunosuppression should be started as soon as a diagnosis has been confirmed. The combination of steroids and cyclophosphamide may induce more patients into remission than steroids alone. Current data do not suggest that rituximab results in better outcomes. Relapse is common (10%-20%) in the first 6 months after immunosuppression is stopped, and patients need to be followed up regularly to allow early diagnosis and treatment of relapse.

pdFVIII/VWF may be an alternative treatment for old medical patient with acquired haemophilia A and systemic vascular disease?

Acquired Haemophilia is a severe, rare and potentially life-threatening bleeding that affects both males and females with an incidence of 1.5 cases/million/year. Mucocutaneous haemorrhages or haematomas are the typical expression of this disease as a consequence of a decrease in FVIII activity and the presence of a FVIII inhibitor, which differs from congenital haemophilia. We report a case of a 71 year-old-man who presented with spontaneous haematomas and severe anaemia and suffered from vascular disease. At admission, all haemostatic and laboratory data were diagnostic for idiopathic AHA. Treatment with by-passing agents such as rFVIIa was contraindicated because of the risk of thromboembolic events. Despite the fact that administration of FVIII concentrates in AHA is recommended only in patients with an inhibitor titre<5.0 BU, the physicians decided to use pdFVIII/vWF with corticosteroids in this patient. One month later, the FVIII was within the normal range and the inhibitors had disappeared. In our case, pdFVIII/vWF resulted in a safe and effective alternative for the treatment of acquired haemophilia A in a patient at high thromboembolic risk.

Severe recurrent achalasia cardia responding to treatment of severe autoimmune acquired haemophilia

Acquired haemophilia A and severe acquired achalasia are both very rare conditions with unknown aetiology. Haemophilia A is a haemorrhagic disease induced by deficiency or malfunction of coagulation factor VIII. Congenital haemophilia is an inherited disease transmitted by the mother through X-linked inheritance and primarily affects males. However, acquired haemophilia A is a serious, sudden-onset, autoimmune disease that affects either sex. In addition, achalasia is a disease of the oesophagus caused by abnormal function of the nerves and muscles. It causes swallowing difficulties due to the inability of the lower oesophageal sphincter to relax during swallowing, leading to dysphagia, regurgitation and chest pain. In this report, we describe the case of a patient with severe, newly diagnosed, acquired haemophilia A with long-standing, recurrent achalasia; the achalasia had recurred 3 times despite complete and proper surgical fixation. Acquired haemophilia A is treated with immunosuppressive therapy. High-dose steroid therapy was administered for 7 months, during which the patient responded well; moreover, the achalasia did not recur for more than 2 years. The response of the achalasia to immunosuppressive therapy suggests that achalasia may be an autoimmune disorder and that there may be an association between both diseases. The findings of the present case suggest that achalasia may favourably respond to steroid therapy as a first-line treatment prior to surgery.

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.

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.

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.

Management of acquired haemophilia A

Acquired haemophilia A is an auto-immune disease caused by an inhibitory antibody to factor VIII. The pattern of bleeding varies but patients remain at risk of life threatening bleeding until the inhibitor has been eradicated. The cornerstones of management are; rapid and accurate diagnosis, control of bleeding, investigation for an underlying cause and eradication of the inhibitor by immunosuppression. Patients should always be managed jointly with a specialist centre even if they present without significant bleeding. Despite an extensive literature, few controlled data are available and treatment guidelines are based on expert opinion. To treat bleeds recombinant factor VIIa and activated prothrombin complex concentrate are equally efficacious but both are superior to factor VIII or desmopressin. Immunosuppression should be started as soon as the diagnosis is made. Commonly used regimens are steroids alone or combined with cytotoxic agents. Rituximab is being used more widely but current evidence does not suggest that it improves outcomes or reduces side effects.

Rituximab therapy for autoimmune haematological diseases

Autoimmune haematological diseases are characterized by the production of antibodies against blood proteins or cells, and comprise primary immune thrombocytopenia, autoimmune haemolytic anaemia, acquired haemophilia, and thrombotic thrombocytopenic purpura. Current treatments for these disorders include corticosteroids, cytotoxic drugs and splenectomy, which may be associated with significant systemic toxicity and/or morbility. B cells play a key role in both the development and perpetuation of autoimmunity, since they produce autoantibodies but also function as antigen-presenting cells, and release immunomodulatory cytokines. Rituximab, an anti-CD20 monoclonal antibody that specifically depletes B cells, may be an effective treatment strategy for patients with autoimmune disorders. This article reviews data of the literature, showing that patients with autoimmune haematological diseases can respond to rituximab irrespective of age and number or type of prior treatments. These data suggest that rituximab provides an effective and well-tolerated treatment option for these conditions.

Factor VIII inhibitors: a 50-year perspective

Inhibitors of factor VIII (FVIII) have been studied for more than 50 years, but diagnostic and therapeutic challenges remain. To describe the features that distinguish alloantibodies from autoantibodies, list predisposing factors, and review methods for tolerance induction and autoantibody suppression. Review of key articles published during the past half-century that have advanced knowledge in this field. Alloantibodies generally bind to the A2 or C2 domains of FVIII and disrupt the formation of the FVIII-FIX complex. They exhibit type 1 reaction kinetics, are saturable by FVIII, and display anamnesis. In contrast, autoantibodies usually bind to the C2 domain of FVIII, interfering with phospholipid and von Willebrand factor binding. They have type-2 kinetics and are poorly neutralized by FVIII. Repeated exposures to FVIII induce tolerance in 70-80% of haemophiliacs with inhibitors, whereas drugs that deplete B-lymphocytes restore self-tolerance to FVIII in a similar percentage of non-haemophiliacs. Future work should focus on improving assays that detect and quantify inhibitors, examining the pathophysiology of inhibitor formation using contemporary immunologic tools, and investigating new treatment modalities. These should include agents to control bleeding with less thrombotic risk, more specific immunomodulating drugs to curtail antibody formation, and, for haemophilia patients, genetic therapies to provide FVIII resistant to or protected from inactivation by inhibitors.

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.

[Two cases of acquired hemophilia A in elderly patients]

Acquired hemophilia A is a rare bleeding diathesis caused by autoantibodies against clotting factor VIII. The incidence of acquired hemophilia A increases with age. We report two cases of acquired hemophilia A in elderly patients and their clinical characteristics. Case 1: A 66-year-old man was referred to our hospital with massive subcutaneous and intramuscular hemorrhage. Prolonged APTT, low factor VIII activity and factor VIII inhibitor with high titer (42 BU/ml ) were observed, confirming the diagnosis of acquired hemophilia A. His hemorrhages disappeared soon after 50 mg/day oral prednisolone was administered. Although early steroid withdrawal lead to repeated prolongation of APTT, the addition of 20 mg/day oral prednisolone successfully decreased the inhibitor titer. The underlying disease was not identified. Case 2: An 85-year-old man with advanced gastric cancer was referred to our division because of severe bleeding. His factor VIII inhibitor titer was 64 BU/ml . Activated prothrombin complex concentrates were used to control the bleeding. Initially, he did not seem to respond to 20 mg/day oral prednisolone, but a further 12 weeks of 20 mg/day prednisolone finally achieved normalization of his hemostatic parameters. Subsequently, he successfully underwent surgery for cancer. The responses to immunosuppressive therapy were very different in the two cases, probably because of the difference in the underlying diseases. The immunosuppressive therapy of acquired hemophilia A should be strictly tailored to the patient's characteristics to minimize treatment-related adverse effects.

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.

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.

International recommendations on the diagnosis and treatment of patients with acquired hemophilia A

Acquired hemophilia A (AHA) is a rare bleeding disorder characterized by autoantibodies directed against circulating coagulation factor (F) VIII. Typically, patients with no prior history of a bleeding disorder present with spontaneous bleeding and an isolated prolonged aPTT. AHA may, however, present without any bleeding symptoms, therefore an isolated prolonged aPTT should always be investigated further irrespective of the clinical findings. Control of acute bleeding is the first priority, and we recommend first-line therapy with bypassing agents such as recombinant activated FVII or activated prothrombin complex concentrate. Once the diagnosis has been achieved, immediate autoantibody eradication to reduce subsequent bleeding risk should be performed. We recommend initial treatment with corticosteroids or combination therapy with corticosteroids and cyclophosphamide and suggest second-line therapy with rituximab if first-line therapy fails or is contraindicated. In contrast to congenital hemophilia, no comparative studies exist to support treatment recommendations for patients with AHA, therefore treatment guidance must rely on the expertise and clinical experience of specialists in the field. The aim of this document is to provide a set of international practice guidelines based on our collective clinical experience in treating patients with AHA and contribute to improved care for this patient group.

B-cell-directed therapies for autoimmune disease

Approval of the anti-CD20 antibody rituximab for the treatment of moderate-to-severe rheumatoid arthritis in patients who fail to respond to anti-tumor-necrosis-factor agents has raised interest in B-cell-directed therapy for this disease. A number of direct and indirect modalities with distinct mechanisms of action are being investigated, including anti-CD20 and anti-CD22 therapies, and new approaches for blocking members of the tumor necrosis factor cytokine family including B cell activating factor (BAFF) and a proliferation ligand (APRIL), which are at late stages of clinical development. Clinical experience is most extensive with rituximab, and suggests that targeting 'autoimmune' memory B cells is a feasible approach for treating autoimmune disease. Although anti-CD20 therapy has only been approved for rheumatoid arthritis thus far, data suggest this approach could be valid for other autoimmune diseases, including systemic lupus erythematosus, Sjögren's syndrome, vasculitides, autoimmune cytopenias, and neurologic and dermatologic autoimmune diseases. Additional studies of direct and indirect B-cell-directed treatments are needed before we can draw conclusions as to the value of this approach in patients with various autoimmune diseases and whether more precisely defined techniques than these are required to target the complex humoral system effectively.

Abbreviated dose rituximab for immune-mediated hematological disorders

As rituximab, a monoclonal antibody targeting CD20, depletes B cells, there is considerable interest in its use in immune-mediated disorders. The majority of studies employ a four-dose regimen based on practice in lymphoma therapy. We describe our experience with one or two doses of 375 mg/m(2) of rituximab in 12 patients with relapsed and refractory immune-mediated hematological disorders. Eleven patients (92%) achieved a complete remission that has been sustained in 7 for a median of 14.5 (10.5-22) months. Four patients (36%) relapsed after responses of 1-18.5 months. This preliminary experience suggests that one or two doses of rituximab may have response and relapse rates comparable to multidose regimens while potentially providing considerable cost savings. Further prospective studies are planned.