Acquired haemophilia: dynamic whole blood coagulation utilized to guide haemostatic therapy

Acquired haemophilia is a rare bleeding disorder caused by autoimmune antibodies interacting with factor VIII (FVIII) or factor IX. Anticipating a high degree of heterogeneity amongst cases, we recently initiated systematic recording of whole blood (WB) coagulation dynamic profiles using our recently developed thrombelastographic method employing very small amounts of tissue factor for activation. Six newly diagnosed patients with acquired haemophilia A in our University Hospital were investigated with the purpose to characterize the WB clotting phenotypes in each patient, as well as inspecting the ex vivo and in vivo response to supplementation with various haemostatic agents. Our results show a striking heterogeneity in patients WB clotting profiles, each patient having a particular pattern and an individual type of response to bypassing agents. Profiles in some of patients resembled severe haemophilia A, even if there was a measurable residual FVIII:C activity while others were more similar moderate-to-mild haemophilia. In one case the profile was very close to normal. Each patient seemed to respond individually to bypassing agents. WB clotting profiles assisted us in selecting an optimal treatment modality in each case and whenever possible, we compared the clinical effects of the treatment selected with the appearance of the WB clotting pattern. In one patient, the ex vivo response to FVIII looked promising, and a approximately 200 IU kg-1 per 24 h high-dose programme nearly normalized the clotting profile in 2-week time. Our preliminary small series of data should be concluded with caution. However, it seems that WB clotting profile studies at baseline, with ex vivo addition of haemostasis promoting agents, and during treatment may hold the potential to predict the success of treatment.     

Tranexamic acid as adjunct therapy to bypassing agents in haemophilia A patients with inhibitors

Haemophilia patients with inhibitors require bypassing agents (BPA) like activated prothrombin complex concentrate (aPCC) and recombinant activated factor VII (rFVIIa) to control bleeds. Adjunct tranexamic acid (TXA) may improve haemostasis. The objective of this study was to investigate safety and haemostatic effect of TXA given in combination with BPA. Healthy volunteers (N = 5) and haemophilia inhibitor patients (N = 6) were enrolled in a prospective case crossover design. Controls were treated with TXA 20 mg kg^?1 orally (O.R.) Patients were treated with aPCC 75 IU kg^?1 intravenous (I.V.) on day 1 followed by TXA 20 mg kg^?1 O.R. combined with aPCC 75 IU kg^?1 I.V. on day 2. A 14‐day washout occurred before crossover to rFVIIa 90 μg kg^?1 I.V. ±TXA. Safety evaluation and blood sampling processes were performed at baseline, 15, 30, 60, 120, 180 and 240 min post treatment. Primary outcome was maximum clot firmness (MCF) evaluated by whole blood thromboelastometry using a TF + tissue plasminogen activator‐based assay. Healthy controls showed a 20‐fold increase in MCF following TXA. Adjunct TXA to aPCC or rFVIIa induced a significant increase in MCF (P < 0.0001) reaching levels indistinguishable from healthy controls treated with TXA (P > 0.05). Infusion of aPCC or rFVIIa alone induced only 3–10 fold increase in MCF from baseline, with a decline in MCF starting after 60–120 min. TXA did not increase the endogenous thrombin potential. No clinical or laboratory signs of thromboembolic events, disseminated intravascular coagulation, or hypercoagulability were observed. Combination of aPCC or rFVIIa with TXA normalizes clot stability in haemophilia patients with inhibitor as compared to healthy controls. No clinical or laboratory adverse events were observed.     

Manipulation of prothrombin concentration improves response to high-dose factor VIIa in a cell-based model of haemophilia

Clinical reports suggest that treatment regimens employing both activated prothrombin complex concentrates (aPCCs) and recombinant activated factor VII (rFVIIa) may control the bleeding in patients with haemophilia who fail to respond to either agent alone. We hypothesised that increased concentrations of prothrombin, as may be observed after the infusion of aPCCs, favourably influence parameters of thrombin generation in haemophilia treated with high-dose rFVIIa. We examined the effect of varied prothrombin and rFVIIa concentrations on thrombin generation in a model of haemophilia. At all concentrations of rFVIIa, increased prothrombin concentrations led to increases in the peak and rate of thrombin generation. In assays with the highest concentrations of prothrombin and rFVIIa, peak thrombin actually equalled that measured in the model of normal haemostasis. The significant impact of prothrombin concentration on the effect of rFVIIa in vitro may explain the improved haemostasis reported with concurrent use of aPCCs and rFVIIa. These results imply that persons with plasma prothrombin levels at either end of the 'normal' range could have significantly different responses to similar rFVIIa doses. Furthermore, these results suggest that increasing plasma prothrombin concentration prior to rFVIIa administration may offer advantages over the use of rFVIIa alone in the treatment of haemophilic bleeding.     

Acquired haemophilia: experiences with a standardized approach

Acquired haemophilia is a rare, life-threatening, acquired bleeding diathesis. No general consensus exists on the best therapeutic approach. We report on the standardized approach at our institution evaluated in ten patients with acquired haemophilia. Factor VIII inhibitors were found in all patients, activities ranging from 1 to 648 Bethesda units (BU). Eight of the ten patients presented with severe bleeding. Two patients died during the acute phase, one from intracranial bleeding and one due to Mycoplasma pneumonia. One patient with mild bleeding was treated with immunosuppression alone. Two patients with factor VIII inhibitor activities below 5 BU were started on factor VIII concentrate therapy. Therapy was successful in one and was changed to recombinant human activated factor VII infusion (rFVIIa) in the other, owing to insufficient factor VIII recovery. Six patients with factor VIII inhibitor activities above 5 BU were started on activated prothrombin complex concentrate (APCC) therapy. APCC treatment was successful initially in all six patients and was changed to rFVIIa infusion in one for rebleeding. One patient did not receive any specific therapy. Immunosuppression with prednisolone (2 mg kg(-1)) was begun in nine patients and was continued with cyclophosphamide (2 mg kg(-1)) in six. A complete remission of the acquired haemophilia was found in seven of the eight patients surviving the acute phase, one had a partial remission. All patients with acquired haemophilia could be managed effectively following our standardized approach. Routine administration of immunosuppression was associated with high inhibitor elimination rates.     

Major surgery in severe haemophilia A with inhibitors using a recombinant factor VIIa and activated prothrombin complex concentrate hybrid regimen

Major surgery in persons with haemophilia A and inhibitors is increasingly being performed. Both recombinant activated factor VII (rFVIIa) and activated prothrombin complex concentrate (APCC) are used to cover surgery but it remains unclear what the optimal dosing schedules are. We describe the use of a hybrid regimen in four inhibitor patients undergoing eight major surgical procedures using rFVIIa in the initial 2–6 postoperative days followed by FEIBA^® for the remaining period. All patients were also treated with tranexamic acid while receiving rFVIIa. We performed six major orthopaedic procedures, one emergency orchidectomy and one open appendectomy. The dosing schedules were at the higher end of those described in the literature but within the recommendations of the summary of product characteristics. Despite this, we encountered non‐surgical bleeding in four of eight episodes. Three of these occurred in one individual suggesting a patient factor. The overall outcome was good for all episodes. The hybrid regimen combines flexibility of dose and dosing frequency of rFVIIa in the immediate postoperative setting with the advantage of a reduced dosing frequency with FEIBA^® in the subsequent days. This study also emphasizes that surgical procedures in this patient group remain a challenge.     

Prophylaxis in haemophilia patients with inhibitors

Summary.   The presence of high titre inhibitors makes the treatment of bleeding episodes in haemophilia patients difficult and increases the risk of uncontrollable bleeding and disability, despite optimum on-demand treatment with bypassing agents. The inability to effectively control joint bleeding leads to progressive joint disease in many patients with inhibitors. Significant mobility impairments are far more prevalent in patients with inhibitors than in those without inhibitors. Emerging data suggest that prophylaxis using bypassing agents may be effective and safe in reducing the incidence of joint bleeding during immune tolerance induction (ITI), and for patients who failed ITI or who were never candidates for ITI. Only controlled clinical trials will ultimately demonstrate whether prophylaxis can prevent joint bleeding and damage, and improve quality of life in patients with inhibitors. This article will review the published data on the use of bypassing agents in the prevention of bleeding, and will discuss ongoing clinical prophylaxis trials in inhibitor patients.     

Postpartum acquired haemophilia: clinical recognition and management

Postpartum acquired haemophilia is a rare but serious complication of an otherwise normal pregnancy. Patients usually present with postpartum haemorrhage (PPH) or uncontrolled bleeding following surgical interventions, which fail to respond to conservative treatment. A high index of clinical suspicion along with early laboratory diagnosis and prompt institution of appropriate therapy is essential for the management of acute bleeding episodes. Our patient, a 32-year-old female, presented with severe PPH and shock. She had undergone dilation and curettage three times, with subsequent total abdominal hysterectomy and internal iliac artery ligation, before she was diagnosed with acquired haemophilia (factor VIII autoantibodies) and an inhibitor level of 8 Bethesda units (BU). The patient underwent an abdominal laparotomy for removal of the abdominal packing used in the previous operation, and blood and blood clots, and was given FEIBA(R) therapy. The patient responded to these measure and the factor VIII inhibitor level decreased to 2 BU at the time of discharge 10 weeks later.     

Use of prothrombin complex concentrates and activated prothrombin complex concentrates as prophylactic therapy in haemophilia patients with inhibitors

Haemophilia patients with inhibitors are treated for acute bleeding with prothrombin complex concentrates (PCCs) or activated prothrombin complex concentrates (aPCCs). Despite this therapy, patients with high-level inhibitors are at increased risk of developing devastating joint disease. This paper examines available information that supports the study of PCCs and/or aPCCs as prophylactic therapy for haemophilia patients with inhibitors. This strategy would require that PCCs or aPCCs be administered repetitively in a dose that is sufficient to prevent haemarthrosis without causing thrombogenic events, or causing anamnestic response in inhibitor titre. PCC doses ranging from 30 to 50 U kg⁻¹ every other day for up to 8 months have resulted in subjective improvement both in bleeding associated with target joints and in the management of chronic joint inflammation. aPCC doses as low as 50–100 U kg⁻¹ every other day have been useful in postsurgical prophylaxis. The risk of developing a myocardial infarction or clinically relevant disseminated intravascular coagulation is linked to total dosages of either PCCs or aPCCs greater than 200 U kg⁻¹ day⁻¹. It is uncertain what anamnestic response would result from prophylaxis, but with typical therapy the aPCCs cause such a response in only a small percentage of patients. Based on these findings, a clinical trial of these products used in doses of 50–100 U kg⁻¹ every other day would appear to be warranted in patients who have permanent inhibitors and frequent joint bleeding.     

Control of bleeding in patients with haemophilia A with inhibitors: a systematic review

This paper reports a systematic review of the best available evidence of clinical effectiveness in the treatment of acute bleeding in haemophilia A patients with inhibitors. Because of the lack of randomized controlled trials (RCTs) on this topic, broad inclusion criteria with regard to study design were applied in order to assess the best available evidence for each intervention. Because of the clinical and methodological heterogeneity of the evidence, it was not appropriate to pool data across studies; instead, data were synthesized using tabulation and qualitative narrative assessment. No evidence was found to support the use of high-dose factor VIII (FVIII) in bleeding episodes. However in surgery it was found to be highly successful (100%) for low-titre, low-responding inhibitors although not reliable for high-responding inhibitors. Porcine FVIII (pFVIII) was effective in the control of severe bleeding episodes with high-titre or high-responding inhibitors (100%) and in 60-90% of surgical procedures. Activated prothrombin complex concentrates (APCCs) appear to be more effective than prothrombin complex concentrates (PCCs) in the control of mild to severe bleeding episodes. There was no good evidence for the use of PCCs in surgery. APCCs controlled bleeding in approximately 90% of surgical episodes. Recombinant factor VIIa (rFVIIa) controlled 70-100% of mild to severe bleeding episodes with high-responding inhibitors, and achieved better results when used early. It was effective in 60-100% of surgical episodes. Doses varied from study to study, and side-effects from mild to infrequent but serious adverse events were reported. The quality of the evidence is variable. Limited evidence relating to other treatment options is also included in the review.     

Elective orthopaedic surgery for haemophilia patients with inhibitors: single centre experience of 40 procedures and review of the literature

Summary. With the introduction of safe and effective factor VIII/IX‐bypassing agents – recombinant activated factor VII (rFVIIa) and plasma‐derived activated prothrombin complex concentrates (pd‐APCC) – elective orthopaedic surgery (EOS) is a viable option for haemophilia patients with inhibitors. We report a series of patients with haemophilia and inhibitors undergoing EOS between 1997 and 2008 using bypassing agents to provide haemostatic cover. All inhibitor patients undergoing EOS and receiving rFVIIa, plasma‐derived prothrombin complex concentrates (pd‐PCC) or pd‐APCC as haemostatic cover were included. Patients were operated on by the same surgeon and were managed by the same haemophilia treatment centre. Forty procedures (25 minor and 15 major) were conducted in 18 patients. Twenty‐one minor cases were covered using rFVIIa, three with pd‐PCC, and one with pd‐APCC; all major cases were covered using rFVIIa. Bleeding was no greater than expected compared with a non‐haemophilic population in all 25 minor procedures. In the major procedure group, there was no excessive bleeding in 40% of cases (6/15) and bleeding completely stopped in response to rFVIIa. For the remaining nine cases, bleeding response to rFVIIa was described as ‘markedly decreased’ or ‘decreased’ in 4/15 cases and ‘unchanged’ in 5/15 cases. Overall, efficacy of rFVIIa, based on final patient outcome, was 85%. One death occurred as a result of sepsis secondary to necrotizing fasciitis. Good control of haemostasis can be achieved with bypassing agents in haemophilia patients with inhibitors undergoing minor EOS; rFVIIa was used as an effective bypassing agent, enabling EOS in patients undergoing minor and major procedures.     

Recombinant VIIa concentrate in the management of bleeding following prothrombin complex concentrate-related myocardial infarction in patients with haemophilia and inhibitors

Prothrombin complex concentrates (PCCs) and, more recently, activated prothrombin complex concentrates (APCCs), are widely used for the treatment of active bleeding in haemophiliacs with inhibitors. Myocardial infarction (MI), associated with the use of these concentrates, is a well-recognized, but uncommon, complication. We review the 14 previous cases published in the literature and describe two additional patients. MI related to the use of activated and non-activated PCCs predominantly affects young patients who often have no preceding history of, or risk factors for, MI and tends to be associated with large cumulative doses of concentrate. The most frequent pathological finding is myocardial haemorrhage, with no evidence of coronary artery atheroma or thrombosis. The management of further bleeding in these patients is difficult. We have safely used recombinant factor VIIa to treat bleeding in the immediate and long-term period following PCC-related MI.     

Sequential therapy with activated prothrombin complex concentrate and recombinant factor VIIa in patients with severe haemophilia and inhibitors

Patients with haemophilia and inhibitors have bleeding episodes that can be refractory to home therapy with either activated prothrombin complex concentrate (APCC) or recombinant factor VIIa (rFVIIa). Sequential therapy with these products has not been widely used because of concern regarding the possibility of thrombosis. This report describes the results of a retrospective chart review of five hospitalized children with severe haemophilia and inhibitors who have been treated with sequential doses of APCC and rFVIIa for refractory bleeding. These patients all had failed home therapy with APCC and rFVIIa alone. A total of 20 admissions were documented covering 170 hospital days, including 91 days of combination therapy. While being closely monitored in the hospital, they received alternating doses of APCC and rFVIIa every 6 h. Anywhere from one to three doses of rFVIIa were given every 2 h between APCC doses. Doses of APCC ranged from 35 to 80 U kg(-1) dose(-1), and doses of rFVIIa ranged from 80 to 225 mcg kg(-1) dose(-1). There was no clinical or laboratory evidence of thrombosis, thrombocytopenia, or disseminated intravascular coagulation (DIC). We found the combination of these factors to be safe and effective for patients with refractory bleeds. However, we recommend this aggressive therapy only in the inpatient setting with careful monitoring of the physical examination and frequent laboratory screening to assess for thrombosis and DIC, and without the concurrent use of antifibrinolytic medications.     

Gene therapy for haemophilia: the end of a ‘royal pathology’ in the third millennium?

Haemophilia is an ideal condition for gene therapy because of its monogenetic character and the fact that it requires only a small amount of the expressed protein to achieve palliation. To date, research in the field of gene therapy for haemophilia has largely relied on retroviruses, adenoviruses and adeno-associated viruses as transfer vectors and the major aims will be to achieve stable longlasting in vivo expression of factors VIII or IX (FVIII or FIX) at therapeutic levels. Two clinical trials have been approved by the US Food and Drug Administration (FDA), using miniadenovirus FVIII and the intrahepatic and intramuscular delivery of adeno-associated virus FIX. In the third millennium, haemophilia treatment should encompass more ambitious goals through gene replacement, to result in permanent and safe haemophilia 'eradication', making haemophilia a part of the history of medicine.     

Gene therapy for haemophilia: prospects and challenges to prevent or reverse inhibitor formation

Monogenic hereditary diseases, such as haemophilia A and B, are ideal targets for gene therapeutic approaches. While these diseases can be treated with protein therapeutics, such as factor VIII (FVIII) or IX (FIX), the notion that permanent transfer of the genes encoding these factors can cure haemophilia is very attractive. An underlying problem with a gene therapy approach, however, is the patient's immune response to the therapeutic protein (as well as to the transmission vector), leading to the formation of inhibitory antibodies. Even more daunting is reversing an existing immune response in patients with pre-existing inhibitors. In this review, we will describe the laboratory and clinical progress, and the challenges met thus far, in achieving the goal of gene therapy efficacy, with a focus on the goal of tolerance induction.     

Paediatric haemophilia with inhibitors: existing management options, treatment gaps and unmet needs

Summary.  Development of inhibitors is a severe complication of haemophilia posing many management challenges. While a long-term goal in inhibitor patients is eradication of inhibitors through immune tolerance induction, bypassing agents such as recombinant activated factor VII (rFVIIa) and activated prothrombin complex concentrate (aPCC) are essential for control of bleeding episodes. Paediatric patients with haemophilia and inhibitors are at particular risk of recurrent haemarthroses, and management of these patients should seek to avoid joint damage and support the child's full social and physical development. Current options for management of bleeding complications include on-demand treatment of acute bleeding episodes, secondary prophylaxis to avoid recurrent bleeds and surgery to treat affected joints. There is also a rationale for adopting prophylactic approaches to prevent bleeding in inhibitor patients, allowing this group similar opportunities for protection against arthropathy development as are given to non-inhibitor patients. This paper, based on a roundtable meeting of haematology experts at the first Zürich Haemophilia Forum in May 2008, reviews the current evidence supporting more intense and prophylactic approaches to manage bleeding risk in paediatric haemophilia patients with inhibitors, and highlights the need for investigations of primary prophylaxis in this vulnerable patient group, to support best long-term outcome.     

Surgery in haemophilic patients with inhibitor: 20 years of experience

Summary.  Surgery in haemophilic patients with inhibitor against factor (F)VIII or FIX is high risk. Surgery may be performed with the administration of sufficiently high dose of FVIII in patients with low-response inhibitor or who, despite having a high response, present a low inhibitor titre at the time of surgery. The use of high doses of FX is more complicated in patients with a low-titre FIX inhibitor, as there is a high risk of anaphylactic reactions. In the case of patients with high-titre inhibitors, several treatments have been proposed, such as porcine FVIII, recombinant FVIIa (rFVIIa), and activated prothrombin complex concentrate (APCC). We present our 20 years' experience in the treatment and subsequent management of haemophilic patients with inhibitor in surgery and evaluate the results obtained with the products available for haemostatic control in 64 surgical procedures. The efficacy we obtained with FVIII is good in 100% of the cases described; we had no haemorrhagic complication (HC) in the 18 procedures in which it was used (three major and 15 minor surgery). With APCC we obtained excellent results with only one HC in a synoviorthesis in the form of bleeding and haematomas out of 32 procedures. Good results were obtained with rFVIIa with few haemorrhagic episodes. Thus, in major surgery there was one HC out of three cases. In minor surgery, greater efficacy was observed using extremely large doses of rFVIIa (≥ 120 mg kg⁻¹ 2h⁻¹) because of the shorter half-life of this factor in this type of patients.     

Acquired haemophilia in the elderly is a severe disease: report of five new cases

Acquired haemophilia is a rare but life-threatening bleeding disease that can be observed in males or females at various ages. In the present study, we report on five cases of acquired factor (F) VIII inhibitors diagnosed in the elderly population over a period of 5 years between 1995 and 1999 in our hospital. The median age of the patients at the time of diagnosis was 76.2 years (66-92 years). In all cases, the diagnosis was suggested by mild to severe bleeding with no previous bleeding history. While the absence of associated conditions is frequently reported especially among the elderly, in our series an underlying disease was found in four out of the five cases: kidney tumour (two cases) and autoimmune disease (two cases). The bleeding was controlled in four patients using porcine FVIII (two cases) or recombinant FVIIa (two cases). The inhibitors were completely resolved in two patients (kidney tumour, GoodPasture syndrome) by treatment of the underlying disease. However, three patients died as direct or indirect consequence of having an inhibitor. Our series confirms and extends previous data reporting the complexity and severity of this disorder. Because bleeding is often severe, a prompt and correct diagnosis is required to provide adequate therapeutic options that take the advanced age of the patients into account.     

Management of haemophilia B patients with inhibitors and anaphylaxis

Summary. The development of inhibitor antibodies is a serious complicaiton of haemophilia in young children. Occurrence of anaphylaxis at the time of inhibitor development is a recently described complication unique to haemophilia B. Management of these inhibitor patients with allergy is complicated due to the absence of any readily available products for treatment of acute bleeding episodes. Clinical experience suggests that recombinant activated factor VII is the most appropriate and logical treatment for acute bleeding episodes in these patients. From the limited information available regarding immune tolerance induction (ITI) in these patients, it appears that ITI regimens have been only minimally successful and are associated with a high rate of complication (nephrotic syndrome).