Acquired haemophilia: review and meta-analysis focused on therapy and prognostic factors

[Acquired haemophilia: Update in 2024]

Acquired hemophilia A (AHA) is a rare autoimmune disorder due to autoantibodies against factor VIII, with a high mortality risk. It should be suspected in subjects with abnormal bleedings, especially subcutaneous bleed associated with prolonged activated partial thromboplastin time (aPTT). AHA is often idiopathic but is associated with autoimmune diseases, malignancies, pregnancy and postpartum period or drugs. Treatment is based on haemostatic agents as by-passants agents such as factor VIIa and activated prothrombine concentrate complex or recombinant porcine factor VIII for severe bleeding. Eradication of inhibitor should be established as soon as the diagnosis is confirmed with steroid alone often associated with cytotoxic agents or rituximab, depending on FVIII activity and inhibitor titer. The purpose of this review is to summarize the epidemiology, etiopathogenesis, diagnosis, treatment of AHA and discuss current recommendations.

Acquired Hemophilia A Diagnosed Based on Gross Hematuria: A Case Report and Literature Review

Acquired hemophilia A (AHA) is an acquired bleeding disorder caused by neutralizing antibodies (inhibitors) against Coagulation Factor VIII (FVIII:C), causing sudden hemorrhagic symptoms (i.e., subcutaneous bleeding, intramuscular bleeding, and hematuria). Herein, this study is aimed at presenting a case of AHA diagnosed based on hematuria and reviewing patients who were diagnosed with AHA due to hematuria. A 67-year-old woman was referred to Atsugi City Hospital with painless gross hematuria that began 4 weeks before presentation. Contrast-enhanced computed tomography (eCT) revealed an approximately 2 cm mass in the right renal pelvis, and the patient's activated partial thromboplastin time (APTT) was elevated (61.4 s). The day after the endoscopic biopsy, the patient was in shock due to a large retroperitoneal hematoma. Although her condition stabilized after intravenous radioembolization, she underwent emergency surgeries several times because of rebleeding within the next 3 weeks. At that time, APTT was more prolonged at 106.4 s, and the FVIII:C level was 2%. Mixing tests showed an upwardly convex curve after 2-h incubation, indicating the presence of an inhibitor. Factor VIII inhibitor titer was ≥5.1 Bethesda unit (BU)/mL. A combined product of Plasma-Derived Factors VIIa and X (pd-FVIIa/FX), as second-line hemostatic therapy, as well as cyclophosphamide (CYP), were administered after Recombinant Activated Factor VIIa (rFVIIa) had been ineffective. Following this, the Factor VIII inhibitor titer was undetectable, FVIII:C levels were restored, and APTT decreased to within the normal range. Gross hematuria was significantly alleviated. However, the patient died of cytomegalovirus and fungal infections due to prolonged immunosuppressive therapy. Although AHA diagnosed based on hematuria may have a better prognosis than others, there have been occasional cases with severe outcomes. APTT, detected upon initial hematological testing in patients with hematuria, may be a potential indicator of an existing AHA.

Acquired haemophilia A in Finland: A nationwide study of incidence, treatment and outcomes

INTRODUCTION

Acquired haemophilia A (AHA) is a bleeding disorder caused by autoantibody development against factor VIII (FVIII). Studies on AHA have mainly focused on patients treated at specialist centres.

AIM

To determine the incidence, clinical characteristics and outcomes of AHA in an unselected population-based patient cohort from Finland.

METHODS

This retrospective observational cohort comprised all cases diagnosed with AHA in Finland between 2006 and 2019. Patients were identified by the two central laboratories performing FVIII antibody testing in Finland, the Finnish Red Cross Blood Service and HUSLAB. Clinical details were collected from all hospitals and healthcare units where patients were treated. This study was performed in conjunction with the AHA in the Nordics study.

RESULTS

The median incidence of AHA was 0.65 per million per year (range 0.19-1.27). Fifty-five patients were identified, with a median age of 76 years and an even sex ratio (51% women). When diagnosed, all had bleeding symptoms with severe bleeds in 92%. First-line immunosuppressive treatment regimens included steroid monotherapy in 31% of cases, steroids and a cytotoxic agent in 51% and a rituximab-based regimen in 16%. Clinical remission was achieved in 71% of cases, and 15% had relapses. Mortality was 13% for bleeds and 9% for treatment-related infections. Overall survival was 64% for 1 year and 56% for 2 years after diagnosis.

CONCLUSIONS

In a nationwide population-based cohort study, we discovered a lower incidence of AHA than previously reported. Mortality among patients with AHA was high, calling for the consideration of updated treatment strategies.

Acquired Hemophilia A after SARS-CoV-2 Immunization: A Narrative Review of a Rare Side Effect

Acquired hemophilia A (AHA) is a rare bleeding disorder (1.4 per million inhabitants per year) caused by neutralizing antibodies against factor VIII. Although uncommon, these autoantibodies can cause a high rate of morbidity and mortality. Several conditions are linked with AHA; based on an EACH2 study, 3.8% of AHA could be connected to infection. In the last four years, most humans have contracted the SARS-CoV-2 infection or have been vaccinated against it. Whether or not COVID-19 immunization might induce AHA remains controversial. This review aims to evaluate the evidence about this possible association. Overall, 18 manuscripts (2 case series and 16 case reports) were included. The anti-SARS-CoV-2 vaccination, as also happens with other vaccines, may stimulate an autoimmune response. However, older individuals with various comorbidities are both at risk of developing AHA and of COVID-19-related morbidity and mortality. Therefore, the COVID-19 vaccine must always be administered because the benefits still outweigh the risks. Yet, we should consider the rare possibility that the activation of an immunological response through vaccination may result in AHA. Detailed registries and prospective studies would be necessary to analyze this post-vaccine acquired bleeding disorder, looking for possible markers and underlying risk factors for developing the disease in association with vaccination.

Inhibitor eradication and treatment for acquired hemophilia A

INTRODUCTION

Acquired hemophilia A (AHA) is a rare hemorrhagic autoimmune disorder characterized by autoantibodies against coagulation factor VIII (FVIII). In approximately half of the cases AHA does not recognize any cause (idiopathic form), while in the other cases it may be triggered by autoimmune disorders, cancers, drugs, infections, or pregnancy. Besides treating the underlying disorder, specific AHA treatment includes management of bleeding, if necessary, and inhibitor eradication.

AREAS COVERED

This narrative review summarizes the main epidemiological, clinical, laboratory, and therapeutic characteristics of AHA. In particular, it is focused on the current therapeutic options for the inhibitor eradication, also showing the latest findings on the innovative therapies. A literature search strategy was performed, without temporal limits, through Medline and PubMed electronic databases.

EXPERT OPINION

Various first-line and second-line immunosuppressive agents are currently available for the management of AHA. Among the latter, the anti-CD20 monoclonal antibody rituximab has been the object of intense research during the last years from investigators as innovative promising eradicating therapy for AHA. Preliminary data from the studies support the use of this drug as a first-line option for newly diagnosed AHA cases.

Genetics and Epigenetics in Acquired Hemophilia A: From Bench to Bedside

Acquired hemophilia A (AHA) is a bleeding disorder characterized by the immunological inhibition of factor VIII (FVIII) of the hemostatic pathway leading to hemorrhagic events. Different domains of FVIII are the target of autoantibodies (mainly immunoglobulin (Ig) G) leading to the deficiency of FVIII. Several factors have been associated with the activation of the auto-immunity towards FVIII. Emerging evidence implicates CD4+ T cell activation in mediating this autoimmune response, with their involvement like that observed in congenital hemophilia A. Several genes such as HLA II DRB*16, DQB1*0502, and CTLA-4 + 49 are responsible for the pathogenesis of AHA. Epigenetic modifications and mainly long-coding RNAS (lncRNAs) are potentially contributing to the pathogenesis of AHA. The treatment approach of AHA includes the management of acute bleeding events and the administration of immunosuppressive medications. This review aimed to summarize the published data on the genetics and epigenetics of AHA. The severity and the mortality of this disease are creating an emerging need for further research in the field of the genetics and epigenetics of acquired hemorrhagic disorder.

Cyclophosphamide vs rituximab for eradicating inhibitors in acquired hemophilia A: A randomized trial in 108 patients

BACKGROUND

Acquired hemophilia A (AHA) is a rare autoimmune disorder due to autoantibodies against Factor VIII, with a high mortality risk. Treatments aim to control bleeding and eradicate antibodies by immunosuppression. International recommendations rely on registers and international expert panels.

METHODS

CREHA, an open-label randomized trial, compared the efficacy and safety of cyclophosphamide and rituximab in association with steroids in patients with newly diagnosed AHA. Participants were treated with 1 mg/kg prednisone daily and randomly assigned to receive either 1.5-2 mg/kg/day cyclophosphamide orally for 6 weeks, or 375 mg/m2 rituximab once weekly for 4 weeks. The primary endpoint was complete remission over 18 months. Secondary endpoints included time to achieve complete remission, relapse occurrence, mortality, infections and bleeding, and severe adverse events.

RESULTS

Recruitment was interrupted because of new treatment recommendations after 108 patients included (58 cyclophosphamide, 50 rituximab). After 18 months, 39 cyclophosphamide patients (67.2 %) and 31 rituximab patients (62.0 %) were in complete remission (OR 1.26; 95 % CI, 0.57 to 2.78). In the poor prognosis group (FVIII < 1 IU/dL, inhibitor titer > 20 BU mL-1), significantly more remissions were observed with cyclophosphamide (22 patients, 78.6 %) than with rituximab (12 patients, 48.0 %; p = 0.02). Relapse rates, deaths, severe infections, and bleeding were similar in the 2 groups. In patients with severe infection, cumulative doses of steroids were significantly higher than in patients without infection (p = 0.03).

CONCLUSION

Cyclophosphamide and rituximab showed similar efficacy and safety. As first line, cyclophosphamide seems preferable, especially in poor prognosis patients, as administered orally and less expensive.

FUNDING

French Ministry of Health.

CLINICALTRIALS

gov number: NCT01808911.

Acquired Hemophilia: A Rare Complication of Pediatric Idiopathic Multicentric Castleman Disease

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

Severe case of postpartum-acquired haemophilia A after laparoscopic cholecystectomy

Acquired factor VIII inhibitor, also known as acquired haemophilia A, has been associated with the postpartum state in young females. Treatment of acquired haemophilia A is focused on two goals: control of bleeding and eliminating the factor VIII inhibitor. Management requires successful intervention to accomplish both goals. Here, we describe the presentation and management of a case of acquired haemophilia A resulting in particularly severe and protracted intra-abdominal bleeding after routine laparoscopic cholecystectomy in a young and otherwise healthy female at 3 months postpartum. Due to diffuse intra-abdominal bleeding, she required return to the operating room on five occasions for intra-abdominal packing, reassessment of bleeding and ultimate fascial closure. Her abdomen was open for 5 days. She was treated with activated recombinant human factor VIIa to bypass inhibited factor VIII, and with immunosuppression using steroids, cyclophosphamide and anti-CD20 monoclonal antibody rituximab. She achieved remission after 6 weeks of treatment.

Hematological Complications in a COVID-19 Patient: A Case Report

Hemophilia A is a hemorrhagic disorder caused by insufficient or inadequate coagulation factor VIII activity. Two different forms are described: congenital, hereditary X-linked, and acquired. Acquired hemophilia A (AHA) is a rare condition and it is defined by the production of autoantibodies neutralizing factor VIII, known as inhibitors. We report the case of a 72-year-old man with a clinical diagnosis of AHA after SARS-CoV-2 infection, which has been described in association with several hematological complications. SARS-CoV-2 infection could represent the immunological trigger for the development of autoantibodies. In our patient, SARS-CoV-2 infection preceded the hemorrhagic complications by 15 days. This lag time is in line with the other cases reported and compatible with the development of an intense immune response with autoantibody production. It is possible that since our patient was affected by type 1 diabetes mellitus, he was more prone to an immune system pathological response against self-antigens. A prompt, appropriate therapeutic intervention with activated recombinant factor VII administration and cyclophosphamide has led to rapid remission of clinical and laboratory findings.

Immunotherapy of acquired hemophilia A

Acquired hemophilia A (AHA) is an autoimmune disorder characterized by the formation of autoantibodies that neutralize the function of coagulation factor VIII. Immunosuppressive therapy (IST) with glucocorticoids, cyclophosphamide, rituximab, or combinations thereof is the standard of care to suppress autoantibody formation and induce remission of AHA. About 80% of patients achieve remission over the course of a few weeks to several months. However, patients with AHA are often elderly and frail and have adverse events from IST. Therefore, guidelines suggest an individualized approach using caution in elderly and frail patients. Prophylaxis with emicizumab may reduce the need for early and aggressive IST in the future.

Key Genes of the Immune System and Predisposition to Acquired Hemophilia A: Evidence from a Spanish Cohort of 49 Patients Using Next-Generation Sequencing

Acquired hemophilia A (AHA) is a rare bleeding disorder caused by the presence of autoantibodies against factor VIII (FVIII). As with other autoimmune diseases, its etiology is complex and its genetic basis is unknown. The aim of this study was to identify the immunogenetic background that predisposes individuals to AHA. HLA and KIR gene clusters, as well as KLRK1, were sequenced using next-generation sequencing in 49 AHA patients. Associations between candidate genes involved in innate and adaptive immune responses and AHA were addressed by comparing the alleles, genotypes, haplotypes, and gene frequencies in the AHA cohort with those in the donors' samples or Spanish population cohort. Two genes of the HLA cluster, as well as rs1049174 in KLRK1, which tags the natural killer (NK) cytotoxic activity haplotype, were found to be linked to AHA. Specifically, A*03:01 (p = 0.024; odds ratio (OR) = 0.26[0.06-0.85]) and DRB1*13:03 (p = 6.8 × 103, OR = 7.56[1.64-51.40]), as well as rs1049174 (p = 0.012), were significantly associated with AHA. In addition, two AHA patients were found to carry one copy each of the low-frequency allele DQB1*03:09 (nallele = 2, 2.04%), which was completely absent in the donors. To the best of our knowledge, this is the first time that the involvement of these specific alleles in the predisposition to AHA has been proposed. Further molecular and functional studies will be needed to unravel their specific contributions. We believe our findings expand the current knowledge on the genetic factors involved in susceptibility to AHA, which will contribute to improving the diagnosis and prognosis of AHA patients.

Emicizumab prophylaxis in patients with acquired haemophilia A (GTH-AHA-EMI): an open-label, single-arm, multicentre, phase 2 study

BACKGROUND

Acquired haemophilia A is caused by neutralising autoantibodies against coagulation factor VIII, leading to severe bleeding. Standard treatment involves immunosuppressive therapy, which is associated with adverse events and mortality in the frail population of patients with acquired haemophilia A. This study investigated whether emicizumab, a factor VIIIa mimetic antibody, protects patients with acquired haemophilia A from bleeding and allows deferral of immunosuppression during the first 12 weeks after diagnosis.

METHODS

We report final results of an open-label, single-arm, phase 2 clinical trial. Adult patients with acquired haemophilia A from 16 haemophilia treatment centres in Germany and Austria were eligible if they had not previously received immunosuppression. Patients received emicizumab subcutaneously (6 and 3 mg/kg on days 1 and 2, 1·5 mg/kg weekly until week 12), but no immunosuppression. Follow-up was until week 24. The primary endpoint was the number of clinically relevant bleeds per patient-week until week 12. Emicizumab was considered effective if the mean bleeding rate was significantly below 0·15 bleeds per patient-week, the rate observed in a previous study of patients with acquired haemophilia A treated with bypassing agents and immunosuppression but no emicizumab. The study is registered with clinicaltrials.gov, NCT04188639 and is complete.

FINDINGS

Of 49 patients screened from March 25, 2021, to June 10, 2022, 47 were enrolled (23 women, 24 men). Median age was 76 years (IQR 66-80), 46 (98%) of 47 patients were White, median factor VIII activity was 1·4 IU/dL (0·3-5·6), and median inhibitor concentration was 11·4 Bethesda units per mL (3·9-42·7). Mean breakthrough bleeding rate was 0·04 bleeds per patient-week (upper 97·5% CI 0·06). 33 (70%) of 47 patients had no bleeding events, seven patients (15%) had one bleed, six patients (13%) had two bleeds, and one patient (2%) had three bleeds. Adverse events of grade 3 or worse included COVID-19 (n=2), acute kidney injury (n=2), and stroke (n=1). Four of 47 patients died, including two deaths related to bleeding, one from COVID-19, and one from cardiac arrest (none were judged as related to emicizumab).

INTERPRETATION

This study suggests that emicizumab prophylaxis prevents bleeding in patients with acquired haemophilia A and that immunosuppressive therapy can be deferred while patients are receiving this treatment. The low number of thromboembolic events, severe infections, and fatalities observed in this study are promising.

FUNDING

This study was supported by funding from Hoffman-La Roche.

Acquired Hemophilia A: Bleeding Pattern and Hemostatic Therapeutic Strategies

Acquired Hemophilia A (AHA) is a rare autoimmune disorder characterized by the onset of a sudden and unexpected bleeding episode in a patient with no personal or family history of bleeding diathesis, and with a typical laboratory feature, i.e., a prolonged activated partial thromboplastin time that is not otherwise explained. This bleeding disorder is caused by autoantibodies directed against the coagulation factor VIII (FVIII). AHA is idiopathic in 50% of cases and is secondary to well-defined diseases in the remaining 50%. AHA affects elderly patients although it has also been observed in the post-partum period. Bleeding manifestations are heterogeneous, ranging from mild to life-threatening bleeds involving limbs and organs. Severe bleeding with a significant decrease in hemoglobin levels must be promptly and adequately treated in order to avoid a worsening of the hemorrhages and their complications. According to international recommendations, the bypass agents (i.e., activated prothrombin complex concentrate and activated recombinant factor VII) and the replacement therapy with recombinant porcine FVIII are considered as the first-line therapy for bleeding control, due to their proven clinical efficacy. Plasma-derived or recombinant FVIII concentrates could be used as second-line treatments. Emicizumab may represent a valid and interesting therapeutic option for prophylaxis of bleeding recurrences.

Immunogenicity of Therapeutic Biological Modalities - Lessons from Hemophilia A Therapies

The introduction and development of biologics such as therapeutic proteins, gene-, and cell-based therapy have revolutionized the scope of treatment for many diseases. However, a significant portion of the patients develop unwanted immune reactions against these novel biological modalities, referred to as immunogenicity, and no longer benefit from the treatments. In the current review, using Hemophilia A (HA) therapy as an example, we will discuss the immunogenicity issue of multiple biological modalities. Currently, the number of therapeutic modalities that are approved or recently explored to treat HA, a hereditary bleeding disorder, is increasing rapidly. These include, but are not limited to, recombinant factor VIII proteins, PEGylated FVIII, FVIII Fc fusion protein, bispecific monoclonal antibodies, gene replacement therapy, gene editing therapy, and cell-based therapy. They offer the patients a broader range of more advanced and effective treatment options, yet immunogenicity remains the most critical complication in the management of this disorder. Recent advances in strategies to manage and mitigate immunogenicity will also be reviewed.

A case of acquired hemophilia A after pancreaticoduodenectomy for distal cholangiocarcinoma

Acquired hemophilia A (AHA) is a rare disease that results from factor VIII inhibitors causing abnormal coagulation, and certain cases may develop after highly invasive surgery. The present case study reports on a 68-year-old male patient who developed AHA after undergoing a subtotal stomach-preserving pancreatoduodenectomy for distal cholangiocarcinoma. The patient experienced complications after surgery, requiring reoperation on postoperative day (PD) 5 due to rupture of the Braun's enterostomy. On PD 6, angiography was performed after bleeding was detected in the jejunal limb, but hemostasis occurred spontaneously during the examination. Bleeding was observed again on PD 8 and direct surgical ligation was performed. On PD 14, bleeding recurred in the jejunal limb and angiography was performed to embolize the periphery of the second jejunal artery. During the procedure, the prothrombin time was normal, but only the activated partial thromboplastin time was prolonged. A close examination of the coagulation system revealed a decrease in factor VIII levels and the presence of factor VIII inhibitors, resulting in the diagnosis of AHA. Administration of steroids was initiated on PD 15 and, in addition to daily blood transfusions, activated prothrombin complex concentrate was administered to achieve hemostasis. The patient was discharged from the intensive care unit on PD 36 but later developed an intractable labial fistula due to suture failure at the gastrojejunostomy site. As the use of factor VIII inhibitors continued despite the administration of steroids, cyclophosphamide (CPA) pulse therapy was added at PD 58. However, CPA was ineffective and the administration of rituximab was initiated on PD 98. After 12 courses of rituximab, the patient tested negative for factor VIII inhibitors on PD 219. On PD 289, labial fistula closure was performed with continuous replacement of factor VIII and the patient was discharged on PD 342.

How I approach bleeding in hospitalized patients

Excessive bleeding is relatively common in adult inpatients, whether as the primary reason for admission or as a development during the hospital stay. Common causes include structural issues, medication effects, and systemic illnesses; occasionally, unexpected bleeding can develop as a result of an undiagnosed or newly acquired bleeding disorder. The first step in caring for the inpatient who is bleeding is to determine whether the bleeding symptom is truly new or whether the patient has a history of abnormal bleeding. Patients with a history of abnormal bleeding may warrant evaluation for inherited bleeding disorders, such as platelet function disorders, von Willebrand disease, hemophilia, or rare factor deficiencies. Patients with no history of bleeding, for whom other causes, such as liver dysfunction, medication effect, disseminated intravascular coagulation, or certain vitamin deficiencies have been ruled out may require evaluation for acquired coagulopathies, such as acquired hemophilia or acquired von Willebrand disease. Here, we present 3 cases to discuss the diagnosis and management of the 2 most common acquired bleeding disorders as well as a patient with a congenital bleeding disorder with a historical diagnosis.

Acquired hemophilia A developing in the perioperative period of pancreatoduodenectomy: a report of two cases

BACKGROUND

Acquired hemophilia A (AHA) is a rare disease characterized by a prolonged activated partial thromboplastin time (aPTT) and the production of coagulation factor VIII inhibitors. We encountered two cases of AHA in the perioperative period of pancreatoduodenectomy (PD).

CASE PRESENTATION

Case 1: A 76-year-old woman with intraductal papillary mucinous carcinoma developed acute cholecystitis 5 days before PD. Despite immediate improvement in her acute cholecystitis with biliary drainage and antibiotics, her aPTT level was prolonged (55.9 s). PD was performed as scheduled. On postoperative day (POD) 2, she developed intra-abdominal hemorrhaging that required reoperation. However, intra-abdominal bleeding and concomitant anemia persisted after reoperation. On POD 13, she was diagnosed with AHA based on the detection of an inhibitor of coagulation factor VIII. Despite hemostatic and immunosuppressive treatment, including massive blood transfusion, her general condition gradually worsened due to continuous bleeding and secondary infections. She ultimately died of multiple organ failure on POD 71. Case 2: An 82-year-old man received PD for distal cholangiocarcinoma. On POD 3, a small amount of blood via abdominal drainage was observed. On POD 4, his aPTT level was prolonged (61.5 s). On POD 8, subcutaneous hemorrhaging of the median wound was observed, and corticosteroids were administered under suspicion of AHA on POD 9. On POD 15, an inhibitor of FVIII was detected, and he was diagnosed with AHA. On POD 17, the aPTT level had normalized, and an inhibitor of FVIII was undetectable. On POD 41, he was discharged without any serious hemorrhagic events.

CONCLUSIONS

AHA may be more frequent than previously reported. When unexplained prolonged aPTT or bleeding symptoms are observed, it is important to keep AHA in mind during the perioperative period of invasive surgery.

Risk factors, treatment and survival rates of late-onset acquired haemophilia A: A cohort study from the Shizuoka Kokuho Database

INTRODUCTION

Acquired haemophilia A (AHA) is a rare disease. The risk factors have yet to be studied.

AIM

We aimed to identify risk factors for late-onset AHA in Japan.

METHODS

A population-based cohort study was conducted using data from the Shizuoka Kokuho Database. The study population was defined as individuals aged ≥60 years. Cause-specific Cox regression analysis was performed to calculate hazard ratios.

RESULTS

Of 1,160,934 registrants, there were 34 patients with newly diagnosed AHA. The mean follow-up period was 5.6 years, and the incidence of AHA was 5.21 per million person-years. Myocardial infarction, diabetes mellitus, solid tumors, antimicrobial agents, phenytoin and anti-dementia drugs, which showed significant differences in the univariate analysis, were excluded from the multivariable analysis because of the small number of cases. Multivariable regression analysis showed that the presence of Alzheimer's disease (hazard ratio [HR]:4.28, 95% confidence interval [CI]:1.67-10.97) and rheumatic disease (HR:4.65, 95% CI:1.79-12.12) increased the risk of AHA development.

CONCLUSION

We found that comorbid Alzheimer's disease is a risk factor of AHA incidence in the general population. Our findings provide insight into the etiology of AHA, and the proof of the coexistence of Alzheimer's disease may support the recent notion that Alzheimer disease is an autoimmune disease.

A case of refractory bleeding from duodenal angioectasia with acquired hemophilia A

Acquired hemophilia A (AHA) is a coagulation disorder related to the factor VIII inhibitors, which might cause intractable bleeding of gastrointestinal tracts. However, its scarcity makes it difficult to recognize AHA as a pitfall of endoscopic hemostasis failure. An 81-year-old female with a history of endoscopic treatment for colon polyps visited a local hospital with chief compliments of bloody stool and severe anemia. During several examinations for the bleeding origin, esophagogastroduodenoscopy depicted a 5 mm-sized hemorrhagic angioectasia of the duodenum, followed by treatment with argon plasma coagulation. However, hemostasis was not achieved by multiple sessions of endoscopic hemostasis and transcatheter arterial embolization, so blood transfusion was repeatedly done and she was transferred to our hospital. Laboratory data showed severe anemia with coagulation disorder. Based on the results of von Willebrand factor activity, factor VIII activity and factor VIII inhibitor, we diagnosed AHA as a comorbidity. Endoscopic hemostasis was confirmed only after improvement of APTT level and negative for the factor VIII inhibitor by hemostatic bypass treatment with recombinant active factor VII and immunosuppressive therapy with prednisolone and cyclophosphamide. In case of refractory bleeding of gastrointestinal tract, we should suspect of a comorbidity of coagulation disorder like AHA.

Acquired haemophilia A in southern Switzerland from 2013 to 2019: a case series

AIMS OF THE STUDY: Acquired haemophilia A is a rare disease with an annual incidence of 1.48 per million. Based on clinical observations, we suspect a higher incidence in southern Switzerland, and aimed at providing local epidemiological data, and clinical information regarding diagnosis, treatment and outcome in our region. METHODS: All adult patients with acquired haemophilia A treated between 2013 and 2019 in our facility were included in the present retrospective analysis. RESULTS: We treated 11 patients with acquired haemophilia A between 2013 and 2019, resulting in an annual incidence of 4.5 per million (95% confidence interval [CI] 0–9.0). Median delay from first symptoms to diagnosis was 4.5 days, and the median age at diagnosis was 79 years (range 23–87). Possible causative conditions were: pregnancy (n = 1), polyarteritis nodosa (n = 1), myelodysplastic syndrome (n = 1), chronic human immunodeficiency virus (HIV) (n = 1), and HIV postexposure prophylaxis (n = 1). In five patients no underlying or associated condition was identified. Median activated partial thromboplastin time (aPTT)) at baseline was 79 seconds (65–117; ref. value <38 sec), and FVIII:C 2.15% (<1–3.75%). A FVIII:C <1% was present in 4/10 patients. Median FVIII-inhibitor titre was 10.3 BU/ml (2.4–75.0 BU/ml). All patients had bleeding symptoms, 5/10 patients had major bleedings, and 7/10 patients were treated with bypassing agents. All patients received corticosteroids; 7/10 patients received immunosuppressive combination therapy. FVIII levels of ≥50% were achieved after a median of 40 days (8–62). One patient had a severe immunosuppressive therapy-related infection. An 87-years-old woman died for reasons not related to acquired haemophilia A or immunosuppressive therapy. CONCLUSIONS: Acquired haemophilia A is a rare disease, but manageable despite the advanced patient age and comorbidities. Its incidence in Southern Switzerland is higher than previously suspected.

Acquired Hemophilia A: An Update on the Etiopathogenesis, Diagnosis, and Treatment

Acquired haemophilia A (AHA) is a rare bleeding disorder caused by inhibitory autoantibodies against coagulation factor VIII (FVIII). AHA is a disease that most commonly affects the elderly but has also been observed in children and in the postpartum period. AHA is idiopathic in 50% of cases and is associated with autoimmune diseases, malignancies, and infections in the remaining 50%. Recently, cases of association between AHA, COVID-19 vaccination, and infection have been reported in the literature. For diagnoses, determining FVIII levels is crucial to distinguish the different causes of aPTT prolongation. Treatment of AHA is based on bypassing agents (recombinant factor VIIa, activated prothrombin complex concentrate) and porcine FVIII to control the bleeding and immunosuppressive therapy (corticosteroids, rituximab, cyclophosphamide) to suppress autoantibody production. It is important to start a prophylactic regimen to prevent further bleeding episodes until the inhibitor is negative. Recently, the series of cases reported in the literature suggest that emicizumab may provide effective and safe haemorrhage prophylaxis in the outpatient setting.

Acquired Hemophilia A: A Retrospective Multicenter Analysis of 42 Patients

INTRODUCTION

Immunosuppressive therapy (IST) for acquired hemophilia A (AHA) results in remission within days to months in 60% to 80% of patients. However, little is known regarding the predictors of response.

AIM

This study aimed to identify the factors that influence response to treatment.

METHODS

The data of 42 patients with AHA from three hospitals were retrospectively analyzed.

RESULTS

All 42 AHA patients received IST; complete treatment data were available for 34 patients. The response rate was 60% among the 5/34 (14.7%) patients who received steroids alone, 70.8% among the 24/34 (70.6%) patients who received steroids plus cyclophosphamide, and 80% among the 5/34 (14.7%) patients who received steroids plus cyclophosphamide and rituximab. Overall, 29/34 (85.3%) patients achieved CR; 4/34 (13.8%) of them relapsed after a median time of 410 (21-1279) days. Adverse events occurred in 14/34 (41.2%) patients: 13/34 (38.2%) had infections and 1/34 (2.9%) developed pancytopenia. In univariate and multivariate Cox regression analyses, FVIII inhibitor titer ≥20 BU/mL was the only significant prognostic factor affecting time to CR. No variable had significant effect on OS.

CONCLUSION

FVIII inhibitory antibody titer ≥20 BU/mL appears to be an important predictor of time to complete response in patients with acquired hemophilia A treated with immunosuppressive therapy.

High levels of factor VIII activity in patients with acquired hemophilia A in remission are associated with unusually low coagulation potentials

BACKGROUND

Elevated factor VIII activity (FVIII:C) is often observed in patients with acquired hemophilia A (PwAHA) in remission. However, comprehensive coagulation potentials in this patient group remain to be investigated.

AIM

To evaluate comprehensive coagulation potentials in PwAHA.

METHODS

We investigated coagulation function in eleven PwAHA with high FVIII:C (> 150 IU/dL) using thrombin generation assay (TGA) and/or rotational thromboelastometry (ROTEM), and compared findings with results obtained from contrived samples generated by spiking recombinant FVIII.

RESULTS

The median FVIII:C and FVIII inhibitor titers during remission in enrolled PwAHA were 206 IU/dL and 0.44 BU/mL, respectively. In all patients, lag time and time to peak were either prolonged or normal compared to contrived samples corresponding to their FVIII:C. However, higher values of peak thrombin and endogenous thrombin potentials compared to contrived samples were observed in two patients. ROTEM parameters were within normal ranges in all cases. One patient (FVIII:C 171 IU/dL) developed venous thrombosis and pulmonary embolism, but TGA parameters showed low or normal coagulation potential compared to contrived samples corresponding to his FVIII:C.

CONCLUSION

PwAHA with high FVIII:C could exhibit lower coagulation potentials than those corresponding to their FVIII:C.

Acquired Hemophilia A In Adults: A Multicenter Study from Turkey

Acquired hemophilia A (AHA) is a rare disease caused by autoantibodies inhibiting factor VIII (FVIII) activity. Although the conditionis usually idiopathic, there may be other underlying diseases. Treatment consists of two steps: treatment of acute bleeding and immunosuppression. In this multicenter study, we aimed to demonstrate the clinical characteristics, management details, and survival of AHA patients in Turkey. Data was collected from eleven centers in Turkey. aPTT, FVIII, FVIII inhibitor, and hemoglobin (HB) levels, mixing test results, and demographics at diagnosis, treatment information, adverse events, bleeding episodes during follow-up, relapses, and outcome were analyzed. Twenty-nine patients were analyzed (58.6% female). No underlying disorder could be detected in 14 patients. The most prevalent etiologies were pregnancy, malignancy and infections. The median FVIII activity and FVIII inhibitor titer at diagnosis were 0.7% (0.0-29.4%) and 32.6 BU (0.6-135.6 BU) respectively. Bleeding was severe in 44.8% of patients. The HB value was significantly lower in patients with severe bleeding. Most of the patients (n = 25, 86.2%) had only one bleeding episode without relapse, three patients (10.3%) had two bleeding episodes, and one patient had more than three bleedings. 21 (75%) patients received hemostatic therapy. The use of recombinant FVIIa was slightly higher than activated prothrombin complex concentrate (15 versus 10 patients). Immunosuppressive treatment was initiated in 26 (93%) patients. Regimens containing steroid, cyclophosphamide, and rituximab in different combinations were the most preferred. The median follow-up period was 13 months (2-156 months). Median overall survival was 154.97 months. Four and six-year survival were 90.9 ± 0.8% and 77.9 ± 14.1% respectively. This is a unique study that investigated the demographic characteristics, treatment approaches, and patient survival of AHA in Turkey.

Acquired Haemophilia A in four north European countries: survey of 181 patients

Acquired haemophilia A (AHA) is a rare bleeding disorder caused by acquired antibodies against coagulation factor VIII. In the Nordic countries, treatment and outcomes have not been studied in recent times. To collect retrospective data on patients diagnosed with AHA in the Nordic countries between 2006 and 2018 and compare demographic data and clinical outcomes with previously published reports, data were collected by six haemophilia centres: three Swedish, one Finnish, one Danish and one Estonian. The study included 181 patients. Median age at diagnosis was 76 (range 5-99) years, with even gender distribution. Type and severity of bleeding was comparable to that in the large European Acquired Haemophilia Registry study (EACH2). Bleedings were primarily treated with activated prothrombin complex concentrate (aPCC) with a high success rate (91%). For immunosuppressive therapy, corticosteroid monotherapy was used most frequently and this may be the cause of the overall lower clinical remission rate compared to the EACH2 study (57% vs. 72%). Survey data on 181 patients collected from four north European countries showed similar demographic and clinical features as in previous studies on AHA. aPCC was used more frequently than in the EACH2 study and the overall remission rate was lower.

Acquired Haemophilia A: A Review of What We Know

Autoantibodies against plasma coagulation factors could be developed by some individuals inducing severe and sometimes fatal bleedings. This clinical entity is called acquired haemophilia. It should be suspected in subjects with acute abnormal bleedings, without personal or familiar history of congenital bleeding disorders with an unexplained prolonged aPTT. It is rare disease, although its incidence may be underestimated due to the low knowledge about it by many specialists, the frequent use of anticoagulant or antiplatelet therapies in the affected population that can mask the diagnosis and, sometimes, a so withering effect that avoid its confirmation. Mortality ranges between 9% and 33% depending on the series in the first 2 months after diagnosis. This mortality is attributed in up to 40% of the cases to infections in the context of immunosuppressive treatments used to eliminate the inhibitor. Factor VIII levels below 1% and high inhibitor titers are conditions of worse response rates. Advanced age, patient's ECOG, and underlying conditions are key prognostic factors for response to treatment and patient survival. To reduce morbidity and mortality in these patients, it is important to have clinical knowledge and access to guidelines to achieve an early diagnosis and to optimize the haemostatic and immunosuppressive treatment. This review aims to contribute to the dissemination of basic concepts on the epidemiology etiopathogenesis, diagnosis, treatment and management of these patients, as well as risk factors to get remission and the longest overall survival to allow individualized care. Especial awareness will be proposed in patients with some underlying conditions like cancer, autoimmune diseases, children, pregnancy or drugs.

Combined immunosuppression for acquired hemophilia A: CyDRi is a highly effective low-toxicity regimen

Acquired hemophilia A (AHA) is a rare severe autoimmune bleeding disorder with significant morbidity and mortality. Although critical for disease control, there is no consensus for the best immunosuppressive regimen. Most authors use steroids first line, followed by other agents for steroid failures. Upfront combined regimens offer the advantage of reduced steroid exposure and toxicity as well as increased efficacy. We retrospectively analyzed data from 32 patients with AHA treated on an identical such institutional protocol: cyclophosphamide 1000 mg on days 1 and 22, dexamethasone 40 mg on days 1, 8, 15, and 22, and rituximab 100 mg on days 1, 8, 15, and 22 (the regimen was termed CyDRi). All patients received at least 1 cycle of CyDRi. If necessary, CyDRi was repeated until remission, no sooner than day 43 of the previous cycle. Bleeding control was rapidly achieved. The median time for bleeding control was 15.5 days (range, 0-429 days; interquartile range, 2.5-29.5 days). Thirty-one (96.8%) of 32 patients achieved durable complete remission (CR); 29 (90.6%) of 32 patients were alive at last follow-up, all of them in CR. The median time to reach first CR was 77 days (range, 19-939 days; interquartile range, 31-115 days). Toxicity and side effects were acceptable and milder than those of commonly used, prolonged steroid therapies. In conclusion, the CyDRi regimen produced markedly higher CR rates and overall survival than currently used sequential regimens. Taken together, CyDRi proved to be an attractive option for the immunosuppression of elderly patients with AHA.

Diagnosis and treatment of acquired factor VIII deficiency: a case report and literature review

Acquired haemophilia A (AHA) is a rare haemorrhagic disease characterized by spontaneous extensive subcutaneous haemorrhage and soft tissue haematoma. The activated partial thromboplastin time is significantly prolonged and cannot be corrected by normal plasma. Approximately 50% of AHA patients lack a specific aetiology, so this can easily result in a misdiagnosis. This current case report describes a 27-year-old male that presented with gingival bleeding, haematuria and haematochezia with no obvious cause. At first, it was thought that he might have experienced anticoagulant rodenticide poisoning, but the subsequent anticoagulant rodenticide test was negative. At the same time, the patient was screened for mutations associated with bleeding and coagulation diseases. Two mutations were identified: a p.Y471H mutation the plasminogen activator, tissue type (PLAT) gene; and a p.Y244Y mutation the serpin family E member 1 (SERPINE1) gene. It should be noted that patient had no previous history of thrombosis or haemorrhagic disease, which confused the diagnosis. A professional haemophilia research centre provided clarification of the diagnosis when anti-factor VIII antibodies were detected. The patient was treated with 30 mg/day prednisone orally. Multiple follow-up examinations showed continuous complete remission. No factor VIII antibodies were detected in his blood and coagulation factor VIII increased significantly.

A Diagnostic of Acquired Hemophilia Following PD1/PDL1 Inhibitors in Advanced Melanoma: The Experience of Two Patients and a Literature Review

Acquired hemophilia A (AHA) is a rare bleeding disorder caused by the development of specific autoantibodies against factor VIII (FVIII). Immunotherapy is a recent therapeutic option that targets the patient's self-tolerance against tumor cells. Because therapeutic effects of the immune checkpoint inhibitors (ICIs) are mediated by enhancing the immune response to restore antitumor immunity, autoimmune-related adverse effects can be seen in up to 80% of patients during treatment and after treatment. A rare hematologic ICIs-related adverse event is AHA. Hereafter we report two cases of AHA developed during anti-PD-1 immunotherapy for advanced melanoma: one secondary to treatment with nivolumab and one secondary to pembrolizumab. Both patients were treated with activated FVII (Novoseven^®, Novo Nordisk, Bagsværd, Denmark) as hemostatic treatment combined with the eradication of antibodies anti-FVIII obtained with rituximab. In the last few years these drugs have significantly improved the therapeutic armamentarium for the management of AHA. Indeed, while FVIIa has proven to be an effective and safe tool for the treatment of acute bleeding related to FVIII autoantibodies, rituximab is a promising alternative for the autoantibodies' elimination and the restoration of normal hemostasis. Our finding supports the use of this combination even in AHA secondary to ICIs treatment.

Immune complications and their management in inherited and acquired bleeding disorders

Disorders of coagulation, resulting in serious risks for bleeding, may be caused by autoantibody formation or by mutations in genes encoding coagulation factors. In the latter case, antidrug antibodies (ADAs) may form against the clotting factor protein drugs used in replacement therapy, as is well documented in the treatment of the X-linked disease hemophilia. Such neutralizing antibodies against factors VIII or IX substantially complicate treatment. Autoantibody formation against factor VIII leads to acquired hemophilia. Although rare, antibody formation may occur in the treatment of other clotting factor deficiencies (eg, against von Willebrand factor [VWF]). The main strategies that have emerged to address these immune responses include (1) clinical immune tolerance induction (ITI) protocols; (2) immune suppression therapies (ISTs); and (3) the development of drugs that can improve hemostasis while bypassing the antibodies against coagulation factors altogether (some of these nonfactor therapies/NFTs are antibody-based, but they are distinct from traditional immunotherapy as they do not target the immune system). Choice of immune or alternative therapy and criteria for selection of a specific regimen for inherited and autoimmune bleeding disorders are explained. ITI serves as an important proof of principle that antigen-specific immune tolerance can be achieved in humans through repeated antigen administration, even in the absence of immune suppression. Finally, novel immunotherapy approaches that are still in the preclinical phase, such as cellular (for instance, regulatory T cell [Treg]) immunotherapies, gene therapy, and oral antigen administration, are discussed.

Acquired Hemophilia A: Current Guidance and Experience from Clinical Practice

In acquired hemophilia A (AHA), autoantibodies to coagulation factor VIII (FVIII) neutralize FVIII activity leading to a potentially severe bleeding diathesis that carries a high rate of morbidity and mortality. This disorder is rare and occurs mainly in adults over 60 years of age or in the postpartum period. The diagnosis should be suspected in patients with new-onset bleeding without a personal or family history of bleeding and can be confirmed via specific assays for FVIII inhibitors. Treatment involves both hemostatic therapies to decrease bleeding and immune modulation strategies to re-establish immune tolerance to FVIII. There are limited data on treatment for refractory disease, based mostly on small case series. Registry studies have informed consensus guidelines for optimal hemostatic therapies and initial immunosuppressive therapies. Additional studies are needed to evaluate novel hemostatic agents and develop biomarkers to risk-stratify treatment while limiting adverse events.

Acquired Haemophilia A: A 15-Year Single-Centre Experience of Demography, Clinical Features and Outcome

Acquired haemophilia A (AHA) is a rare severe bleeding disorder resulting from the production of autoantibodies directed against coagulation factor VIII. At presentation, bleeding events can be severe, and an early diagnosis and treatment are of major importance. The current study aims to analyse the treated patients who have been diagnosed with AHA for a better understanding of our population and treatment outcome. We conducted a retrospective study with 26 patients who had been diagnosed with AHA and who were treated in our hospital between January 2006 and January 2021. The patients ranged in age from 30 to 85 years old: 46.10% were men, 46.10% had no known underlying condition, 27% had an underlying malignancy, 7.60% presented with other diseases: psoriatic arthritis and Paget's disease, and 19.30% presented with AHA during puerperium. All of the patients had bleeding events and were treated with bypass agents for this as well as with immunosuppressive therapy to eradicate the inhibitor. A total of 53.80% of the patients had major bleeding. Sixty-nine percent of the patients achieved complete remission, but 26.90% died during the follow-up, although bleeding was not the cause of death in any of these cases. Our observations underline the importance of clinical suspicion and early referral to centres with experience and laboratory facilities for managing AHA.

Acquired haemophilia A associated to autoimmune thyroiditis and pangastritis

Acquired haemophilia A is a rare condition defined by the presence of coagulation inhibitors, which are autoantibodies directed against factor VIII that interfere with its activity. We report a case of a 69-year-old woman that presented with knee haemarthrosis followed by spontaneous retroperitoneal haematoma. On coagulation studies, she presented normal prothrombin time with prolonged activated partial thromboplastin time non-correcting on mixture test, low titers of factor VIII and was detected factor VIII inhibitor that led to diagnosis of acquired haemophilia A. She was managed with supportive measures to control haemorrhage and immunosuppressive therapy to eradicate inhibitors, initially with corticosteroids, with partial transitory response, after which she developed new spontaneous haematomas. Rituximab was started at that time, with a good outcome. The additional aetiological study identified autoimmune thyroiditis and autoimmune pangastritis, an association rarely described in literature.

Case of acquired haemophilia a in Southeast Asia following COVID-19 vaccine

Acquired haemophilia A (AHA) is a rare bleeding disorder with high morbidity and mortality, but it is eminently treatable if diagnosis and treatment are prompt. We report a case of AHA in Southeast Asia following the administration of the Pfizer-BioNTech COVID-19 vaccine. A man in his 80s developed multiple bruises 2 weeks after his first dose of the COVID-19 vaccine. Diagnosis was delayed due to his cognitive impairment and low clinical suspicion. This led to a representation with worsening ecchymosis, a left thigh haematoma and symptomatic anaemia. Laboratory testing was notable for an isolated prolongation of the activated partial thromboplastin time, which remained uncorrected in the mixing test. Further testing confirmed the presence of factor VIII (FVIII) inhibitors and low FVIII titres of 6.7%. He responded to treatment with intravenous methylprednisolone and recombinant activated FVII. Screening for autoimmune diseases and malignancies was negative.

Acquired Hemophilia A: A Permanent Challenge for All Physicians

Acquired hemophilia A (AHA) is a rare disease with a prevalence in Europe of 1.5 per million. This diagnosis is significantly delayed in about one-third of all cases, leading to deferred treatment. The main signs of AHA are spontaneous bleeding seen in about two-thirds of all patients. AHA can be lethal in 20% of all symptomatic cases. This patient population’s main standard laboratory finding is a prolonged aPTT (activated prothrombin Time) with otherwise normal coagulation results. In addition, antibodies against FVIII (in Bethesda Units) and a quantitative reduction of FVIII activity are necessary to confirm AHA. The therapy of acute bleeding related to AHA is based on the following main principles: Pharmacologic control of the bleeding is of absolute importance. It can be achieved by administering either recombinant activated FVIIa “bypass therapy”; activated prothrombin complex; or Emicizumab, a bispecific monoclonal antibody. Eradication of the FVIII antibodies should be initiated simultaneously. The combination of steroids with cyclophosphamide leads to the highest eradication rates. Causes of AHA may be related to neoplasms, autoimmune diseases, and pregnancy. We report on a patient who underwent four surgical procedures before the diagnosis of AHA was established.

Recombinant porcine factor VIII in acquired hemophilia A: Experience from two patients and literature review

Background

Acquired hemophilia A (AHA) is a disease caused by antibody formation inhibiting the function of factor VIII, causing bleeding. Recombinant porcine factor VIII (rpFVIII) escapes human FVIII antibody recognition and can provide life-saving hemostasis. However, the development of antibodies against pFVIII can limit its use. We report two cases in which loss of response to rpFVIII occurred, likely because of inhibiting antibodies. In case 1, the patient achieved hemostasis but lost response to rpFVIII within a few days. In the second case, rpFVIII controlled bleeding but the patient experienced diminishing half-life of rpFVIII infusions over time, necessitating a switch to emicizumab which provided lasting hemostasis.

Key Clinical Question

Based on our experience with these cases, we reviewed the available literature regarding the use of rpFVIII in AHA. The Key Clinical Question was to determine how often inhibitors were associated with rpFVIII treatment failure.

Clinical approach and conclusions

We identified 43 AHA patients across five studies who were treated with rpFVIII. Twenty-two patients (51%) developed pFVIII inhibitors and seven cases (16%) reported loss of efficacy associated with an inhibitor. In conclusion, rpFVIII can be a life-saving therapy in AHA. However, clinicians should be aware that pFVIII antibody development can reduce the efficacy and duration of response. Recombinant pFVIII's limitations support the utility of further investigation of alternative therapies such as emicizumab in early AHA management.

[Examination of the effect of immunosuppressive therapy on acquired hemophilia A in elderly patients with bloodstream infections]

AIM

Acquired hemophilia A (AHA) is an acquired autoantibody (inhibitor) against blood coagulation factor VIII (FVIII) that significantly reduces FVIII activity and causes a bleeding tendency. Immune acquired coagulation factor deficiency. The peak age of onset is in the 70s. In Japan, which has an aging society, the number of reports has recently been increasing, and it should be noted that AHA is a bleeding disease that can occur in the elderly. Examined 5 cases of AHA that were experienced in our hospital. The FVIII inhibitor level, APTT, underlying disease, treatment history, and outcome were retrospectively examined using medical records.

RESULTS

The age of onset was 76-93 years. At the time of diagnosis, the Hb (mg/dL) value was 6.1-10.3, the APTT was 75.6-203.2 seconds, the FVIII inhibitor value (BU/mL) was 18-686, and the platelet count was within the normal range in all cases. Bleeding control was possible using a bypass hemostatic agent in 4 patients. All patients underwent immunosuppressive therapy. Two patients were discharged alive and 3 patients died. The cause of death was infectious disease in all cases. The total prednisolone-equivalent dose of the deceased patients was 1,240-3,206 mg; one patient was treated with cyclophosphamide and was treated with dexamethasone.

CONCLUSION

Long-term immunosuppressive therapy is expected to increase the risk of infection in elderly patients. The risk assessment of AHA treatment-related bloodstream infections is insufficient, and it will be necessary to accumulate data and consider appropriate assessments and countermeasures.

Could a Haematoma Be Due to an Acquired Phenomenon?

Acquired hemophilia, as opposed to congenital hemophilia, develops in individuals with no previous history of bleeding disorder with almost similar numbers of males and females affected. It is predominantly a disease of the elderly. It is an autoimmune disorder and occurs when the immune system produces antibodies that mistakenly attack healthy tissue, specifically the clotting factors, in particular clotting factor VIII. As a result, affected individuals develop abnormal uncontrolled bleeding into the muscles, soft tissues, and the skin and it can occur spontaneously during surgery, or following trauma, and potentially cause life-threatening bleeding complications in severe cases. The affected individuals may remain undiagnosed or be misdiagnosed, making it difficult to determine the actual frequency of the disorder in the general population. The clinical presentation should suspect it with confirmation by an abnormal coagulation test. Typical laboratory results with a recent onset of abnormal bleeding and an isolated prolongation of the activated partial thromboplastin time (APTT), especially in the elderly and peri- and post-partum women, should raise eyebrows. We present two cases following different symptomatology and emphasize the clinical challenges for junior medical doctors who receive patients on the front end. We hope to emphasize understanding simple coagulation blood results followed by a meaningful discussion with the hematology team towards appropriate and timely management of the bleeding diathesis. We hope this case series report will help junior medical doctors manage patients appropriately and consult with their hematology colleagues.

Predictive significance of anti-FVIII immunoglobulin patterns on bleeding phenotype and outcomes in acquired hemophilia A: Results from the Quebec Reference Center for Inhibitors

BACKGROUND

Acquired hemophilia A (AHA) is a potentially life-threatening bleeding disorder caused by factor VIII (FVIII) autoantibodies, involving various immunoglobulin (Ig) isotypes and IgG subclasses.

OBJECTIVES

We analyzed the profile of Ig against FVIII in patients with AHA to identify Ig patterns predictive of bleeding phenotype and outcomes.

PATIENTS/METHODS

Ig detection and titration were determined by enzyme-linked immunosorbent assay (ELISA) at disease presentation in a cohort of 66 subjects from the Quebec Reference Centre for Inhibitors registry.

RESULTS

Most of plasma samples analyzed (97%) contained multiple anti-FVIII Ig isotypes and IgG subclasses, IgG(1,2,3,4) (24.2%), [IgG(1,2,3,4),IgA] (16.7%) and IgG(2.4) (13.6%) being the most prevalent combinations of Ig detected. AHA patients who presented with IgA antibodies were more likely to have an associated auto-immune disease (p = .049). The presence of IgG4-was associated with bleeding symptoms at presentation (p = .002). IgG1-positive patients were more likely to require transfusions with red packed cell (p = .014) whereas IgM detection was associated with a higher probability of death linked to AHA (p = .011).

CONCLUSION

The Ig pattern of AHA patients at diagnosis is widely heterogeneous and is at least partially associated with some underlying conditions. Our data supports the differential predictive significance for IgG1, IgG4 and IgM on bleeding severity and suggests that the early determination of Ig profile may help to identify AHA patients at higher risk of poorer outcomes.

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

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

Management of acquired hemophilia A: results from the Spanish registry

The Spanish Acquired Hemophilia A (AHA) Registry is intended to update the status of AHA in Spain. One hundred and fifty-four patients were included and retrospectively followed for a median of 12 months. Patients were predominantly male (56.3%), with median age at diagnosis of 74 years. AHA was more frequently idiopathic (44.1%) and autoimmune disorder-associated (31.7%). Thirty-four percent of patients were on antithrombotic therapy at diagnosis. Hemostatic treatment was used in 70% of patients. Recombinant activated factor VII was more frequently infused (60.3% vs 20.6% activated prothrombin complex concentrate). Only 1 patient did not achieve control of hemorrhage. Complete remission (CR) was achieved by 84.2% of cases after immunosuppressive therapy. Steroids alone were less efficient than the other strategies (68.2% vs 87.2%, P = .049), whereas no differences existed among these (steroids/cyclophosphamide, 88.5%, vs steroids/calcineurin inhibitors, 81.2%, vs rituximab-based regimens, 87.5%). Female sex and high inhibitor levels influenced CR negatively. Thirty-six deaths (23.8%) were reported. Main causes of death were infection (15 patients, 9.9%) and hemorrhage (5 patients, 3.3%). All hemorrhage-related and half the infection-related deaths occurred within 2 months of diagnosis. Prior antithrombotic therapy was inversely associated with survival, irrespective of age. Median age of nonsurvivors was significantly higher (79 vs 73 years in survivors). Patients dying of infection were older than the other nonsurvivors (85 vs 78 years). In summary, fatal infection in the first months is common in our series. Antithrombotic therapy is associated with mortality. Particular care should be taken to avoid misdiagnosis.

Diagnosis and Management of Acquired Hemophilia A: Case Reports and a Literature Review

Background

Acquired hemophilia A (AHA) is a potentially life-threatening autoimmune hemostatic disorder where autoantibodies that disrupt the functions of factor VIII (FVIII) are present in the circulation. The early diagnosis of AHA is difficult since the symptoms of AHA differ from those of congenital hemophilia A. Furthermore, the management of AHA is also more complex due to the presence of autoantibodies against FVIII (FVIII inhibitors). Here, we present three case reports and conduct a literature review of AHA with the aim to increase awareness and knowledge regarding the diagnosis and treatment of AHA. Case Presentations. We present three patients diagnosed with AHA in these case reports. The first patient was a young female, while the second and third patients were middle-aged and elderly males, respectively. All patients presented with a chief complaint of bruises without hemarthrosis and a history of bleeding. Laboratory examinations of the patients revealed isolated prolonged aPTT, normal PT, and the presence of autoantibodies against factor VIII, which are characteristics of AHA. Patients were then treated with corticosteroids to reduce the titer level of autoantibodies and received factor VIII transfusion to stop bleeding.

Conclusion

AHA can be suspected in patients presenting with symptoms of bruises without hemarthrosis and without the history of bleeding. Isolated aPTT elevation with normal PT should raise high suspicion of AHA. The presence of FVIII inhibitors can help to confirm the diagnosis of AHA. Treatment consists of factor VIII transfusion and corticosteroid therapy. Bypassing agents are recommended as an alternative to FVIII transfusion.

Newly acquired factor VIII deficiency in a male Ex-smoker - A case report

Introduction

Acquired hemophilia A (AHA) also known as acquired factor VIII (FVIII) deficiency is an acquired inhibition of coagulation by antibodies that either inhibit the activity or increase the clearance of a clotting factor (FVIII). Mortality in patients presenting with AHA is related to bleeding and hemorrhage, therefore rapid diagnosis and effective treatment are needed.

Case presentation

We present a case of a 59-year-old male with acquired VIII deficiency presenting with diffuse ecchymosis and bleeding diathesis. The patient was treated successfully with steroids and rituximab.

Clinical discussion

It is a rare autoimmune disorder caused by neutralization of Factor VIII by IgG antibodies. This can lead to severe, life threatening bleeding. Treatment involves replacement of FVIII and immunosuppression.

Conclusion

A key point to successfully treating AHA is to remove inhibitors and stop bleeding. Mortality in patients presenting with AHA is related to the bleeding and hemorrhage, therefore rapid diagnosis and effective treatment are needed.

Acquired Hemophilia A

Acquired hemophilia A is a potentially severe bleeding disorder caused by antibodies against the patient's own factor VIII. Acquired hemophilia A is rare. It is most commonly diagnosed in older individuals; about one-half of cases of acquired hemophilia are associated with underlying conditions, including autoimmune disease, cancer, and pregnancy. The diagnosis of acquired hemophilia A can be suspect with an isolated activated partial thromboplastin time elevation, and confirmed with demonstration of reduced factor VIII activity and the presence of a specific factor VIII inhibitor. Treatment of acquired hemophilia A involves control of bleeding, and eradication of the inhibitor.

Acute Compartment Syndrome of the Upper Extremity in Acquired Hemophilia A: A Case Report and Literature Review

CASE

Acute compartment syndrome (ACS) with acquired hemophilia A (AHA) is rare and has no established treatment strategy. A 64-year-old woman presented with a giant hematoma in the rectus abdominis. Laboratory findings included decreased hemoglobin and increased activated partial thromboplastin time. Arterial embolization was performed for hemostasis. After catheter removal, she developed severe arm pain and numbness with blistering. Fasciotomy was performed to decrease intracompartmental pressure. Laboratory investigations revealed decreased factor VIII (FVIII) activity and increased FVIII inhibitor. AHA was diagnosed and treated with immunosuppressive and FVIII inhibitor-bypassing agents.

CONCLUSIONS

Fasciotomy should be performed promptly if ACS with AHA is suspected.