Emicizumab versus immunosuppressive therapy for the management of acquired hemophilia A.

BACKGROUND: Acquired hemophilia A (AHA) is an autoimmune bleeding disorder caused by neutralizing antibodies against coagulation factor VIII (FVIII). Immunosuppressive therapy (IST) is standard of care to eradicate autoantibody production and protect from further bleeding but carries a risk of severe infection and mortality in frail patients with AHA. Recently, emicizumab has been studied for its potential to reduce the need for early and aggressive IST. OBJECTIVE: To compare outcomes of two studies that used either IST (GTH-AH 01/2010; n=101) or prophylaxis with emicizumab (GHT-AHA-EMI; n=47) early after diagnosis of AHA. METHODS: Baseline characteristics were balanced by propensity score matching. Primary endpoint was the rate of clinically relevant new bleeds during the first 12 weeks; secondary endpoints were adverse events and overall survival. RESULTS: The negative binominal model-based bleeding rate was 68% lower with emicizumab as compared with IST (incident rate ratio 0.325, 95% confidence interval (CI) 0.182-0.581). No difference was apparent in the overall frequency of infections (emicizumab 21%, IST 29%) during the first 12 weeks, but infections were less often fatal in emicizumab treated patients (0%) compared with IST treated patients (11%). Thromboembolic events occurred less often with emicizumab (2%) than IST (7%). Overall survival after 24 weeks was better with emicizumab (90% versus 76%, HR 0.44; 95% CI 0.24-0.81). CONCLUSION: Using emicizumab instead of IST in the early phase after initial diagnosis of AHA reduced bleeding and fatal infections, and improved overall survival.

Patient perspective on living with mild hemophilia in Germany: results from a nationwide survey.

Introduction: The disease burden and bleeding risk of patients with mild hemophilia may be underestimated. Their health-related quality of life (QoL) may be negatively impacted by insufficient treatment and bleed-related joint damage connected to a potentially delayed diagnosis. Aim: This study aims to gain information on the care reality and QoL of patients aged ≥12 years with mild hemophilia in Germany. Methods: An anonymous cross-sectional patient survey using standardized questionnaires was conducted in a validated electronic patient-reported outcome system. Medical specialists, hemophilia centers, patient organizations, and support groups across Germany invited the patients. Results: A total of 43 patients (35 patients with hemophilia A, 5 patients with hemophilia B, and 3 patients for whom the information was missing) with a median age of 33 years were analyzed. The median age at diagnosis was 6.0 years (interquartile range [IQR] 2.0-15.0), and the median factor activity was 14.0% (IQR 12.0-25.0). Nearly 85% of the patients received factor concentrates in the past, and the most common reasons for the treatment were surgery or joint bleeding (each 65.6%). Half of the patients who provided feedback experienced complications during bleeding episodes. Prophylactic treatment with factor concentrates was rare (10.3%). The patients had minor problems regarding their health status. Conclusion: Bleeding complications and joint bleeding, in particular, may be highly underestimated in patients with mild hemophilia, highlighting a medical need in this population. Patients with a potential benefit from prophylaxis need to be identified. Mild hemophilia has a negative impact on patients' QoL. Hemophilia centers satisfied the patients' needs. Further research is needed to address the current lack of awareness and improve adequate treatment in the future.

Emicizumab for the Treatment of Acquired Hemophilia A: Consensus Recommendations from the GTH-AHA Working Group.

BACKGROUND: Acquired hemophilia A (AHA) is a severe bleeding disorder caused by autoantibodies against coagulation factor VIII (FVIII). Standard treatment consists of bleeding control with bypassing agents and immunosuppressive therapy. Emicizumab is a bispecific antibody that mimics the function of activated FVIII irrespective of the presence of neutralizing antibodies. Recently, the GTH-AHA-EMI study demonstrated that emicizumab prevents bleeds and allows to postpone immunosuppression, which may influence future treatment strategies. AIM: To provide clinical practice recommendations on the use of emicizumab in AHA. METHODS: A Delphi procedure was conducted among 33 experts from 16 German and Austrian hemophilia care centers. Statements were scored on a scale of 1 to 9, and agreement was defined as a score of ≥7. Consensus was defined as ≥75% agreement among participants, and strong consensus as ≥95% agreement. RESULTS: Strong consensus was reached that emicizumab is effective for bleed prophylaxis and should be considered from the time of diagnosis (100% consensus). A fast-loading regimen of 6 mg/kg on day 1 and 3 mg/kg on day 2 should be used if rapid bleeding prophylaxis is required (94%). Maintenance doses of 1.5 mg/kg once weekly should be given (91%). Immunosuppression should be offered to patients on emicizumab if they are eligible based on physical status (97%). Emicizumab should be discontinued when remission of AHA is achieved (97%). CONCLUSION: These GTH consensus recommendations provide guidance to physicians on the use of emicizumab in AHA and follow the results of clinical trials that have shown emicizumab is effective in preventing bleeding in AHA.

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.

Expression and Release of Tumor Cell Tissue Factor Triggers Recurrent Thromboembolism in a Patient with Endometrial Cancer.

Although cancer-associated thrombosis (CAT) is a frequent complication in patients with malignancies, its treatment remains a challenge in daily practice. Here, we report the clinical course of a 51-year-old woman presenting with a highly thrombogenic paraneoplastic coagulopathy. Despite therapeutic anticoagulation with various agents, including rivaroxaban, fondaparinux, and low-molecular-weight heparin, the patient suffered from recurrent venous and arterial thromboembolism. Locally advanced endometrial cancer was identified. Tumor cells showed strong expression of tissue factor (TF), and significant concentrations of TF-bearing microvesicles were detected in patient plasma. Coagulopathy was controlled only by continuous intravenous anticoagulation with the direct thrombin inhibitor, argatroban. Multimodal antineoplastic treatment, including neoadjuvant chemotherapy followed by surgery and postoperative radiotherapy, resulted in clinical cancer remission, which was paralleled by normalization of tumor markers, CA125 and CA19-9, D-dimer levels, and TF-bearing microvesicles. In summary, continuous anticoagulation with argatroban and multimodal anticancer treatment may be necessary to control TF-driven coagulation activation with recurrent CAT in endometrial cancer.

Synovitis and joint health in patients with haemophilia: Statements from a European e-Delphi consensus study.

INTRODUCTION: Synovitis, a common feature in haemophilia, is triggered by the presence of blood in joints, and represents the first step towards the development of chronic arthropathy. Synovitis may be detected early by means of ultrasound or magnetic resonance imaging scan; clinical joint scores are less sensitive in this setting. Regular long-term prophylaxis with clotting factor concentrates, as primary prophylaxis and tailored to individual needs, has high efficacy in preventing synovitis. In general, higher factor levels lower bleeding risk, but no direct correlation between factor levels and synovitis incidence has been demonstrated. AIM: This study aimed to develop an expert consensus relating to the definition, pathophysiology, diagnosis, prevention, follow-up and treatment of synovitis, recognising its relevance for joint health and taking into account existing knowledge gaps. METHODS: A Delphi consensus study was designed and performed. An expert group prepared 22 statements based on existing literature; a wider expert panel subsequently voted on these. RESULTS: Retention of panellists was high. Four statements required amending and consensus on all statements was achieved after three rounds of voting. CONCLUSION: This e-Delphi consensus study addressed the importance of synovitis in joint health of people with haemophilia and highlighted knowledge gaps in this field. Studies on the natural course of synovitis are lacking and the biological mechanisms underlying this process are not yet fully elucidated. While basic and clinical research proceeds in this field, expert consensus can help guide clinicians in their routine clinical practice, and Delphi methodology is often used to produce best-practice guidelines.

[Gene therapy of Hemophilia: Recommendations from the German, Austrian, and Swiss Society for Thrombosis and Haemostasis Research (GTH)]. / Gentherapie der Hämophilie: Empfehlung der Gesellschaft für Thrombose- und Hämostaseforschung (GTH).

Gene therapy has recently become a realistic treatment perspective for patients with hemophilia. Reviewing the literature and our personal experience from clinical trials, we discuss key aspects of hemophilia A and B gene therapy with vectors derived from adeno-associated virus, including predictable results, risks, adverse events, and patient-reported outcomes. Patient selection, informed consent, administration, and monitoring of gene therapy as well as data collection are explained. We also discuss the need for interdisciplinary cooperation with hepatology and other specialties. We emphasize structural and organizational requirements for treatment centers according to the hub-and-spoke model and recommend the use of electronic diaries to ensure safe and timely collection and exchange of data. Electronic diaries will play a key role as a primary source of data for pharmacovigilance, postmarketing clinical studies, national and international registries, as well as health technology and benefit assessment. Reimbursement aspects and the future of gene therapy in adolescents and children are also considered. In a rapidly evolving scientific environment, these recommendations aim to support treatment providers and payers to prepare for the implementation of gene therapy following marketing authorization.

Targets of autoantibodies in acquired hemophilia A are not restricted to factor VIII: data from the GTH-AH 01/2010 study.

The root cause of autoantibody formation against factor VIII (FVIII) in acquired hemophilia A (AHA) remains unclear. We aimed to assess whether AHA is exclusively associated with autoantibodies toward FVIII or whether patients also produce increased levels of autoantibodies against other targets. A case-control study was performed enrolling patients with AHA and age-matched controls. Human epithelial cell (HEp-2) immunofluorescence was applied to screen for antinuclear (ANA) and anticytoplasmic autoantibodies. Screening for autoantibodies against extractable nuclear antigens was performed by enzyme immunoassay detecting SS-A/Ro, SS-B/La, U1RNP, Scl-70, Jo-1, centromere B, Sm, double-stranded DNA, and α-fodrin (AF). Patients with AHA were more often positive for ANA than control patients (64% vs 30%; odds ratio [OR] 4.02, 1.98-8.18) and had higher ANA titers detected than controls. Cytoplasmic autoantibodies and anti-AF immunoglobulin A autoantibodies were also more frequent in patients with AHA compared with controls. Autoantibodies against any target other than FVIII were found in 78% of patients with AHA compared with 46% of controls (OR 4.16, 1.98-8.39). Results were similar preforming sensitivity analyses (excluding either subjects with autoimmune disorders, cancer, pregnancy, or immunosuppressive medication at baseline) and in multivariable binary logistic regression. To exclude that autoantibody staining was merely a result of cross-reactivity of anti-FVIII autoantibodies, we tested a mix of 7 well-characterized monoclonal anti-FVIII antibodies. These antibodies did not stain HEp-2 cells used for ANA detection. In conclusion, a diverse pattern of autoantibodies is associated with AHA, suggesting that a more general breakdown of immune tolerance might be involved in its pathology.

Evaluation of different diagnostic tools for detection of acquired von Willebrand syndrome in patients with polycythemia vera or essential thrombocythemia.

INTRODUCTION: Patients with myeloproliferative neoplasms (MPNs) are at increased risk of both thromboembolic and hemorrhagic complications. Among the risk factors for bleeding is the development of an acquired qualitative von Willebrand factor defect with loss of larger VWF plasma multimers, resulting in acquired von Willebrand syndrome (aVWS). The diagnosis of aVWS is challenging, because no single automated test is sufficient to prove or exclude aVWS. We aimed to compare different diagnostic tools used for the detection of MPN-associated aVWS in daily practice. METHODS: Patients with polycythemia vera (PV) or essential thrombocythemia (ET), who had been routinely assessed for quantitative and qualitative abnormalities of plasma VWF, were retrospectively studied. RESULTS: Sixty-four patients (37 with PV and 27 with ET) were analyzed. Using multimer analysis of plasma VWF, aVWS with a loss of VWF high-molecular-weight multimers was detected in 51.4 % and 55.6 % of PV and ET patients, respectively. A VWF: GPIbM/Ag threshold of <0.8 was defined as useful screening tool for aVWS, with acceptable sensitivity (88.2 %) and specificity (76.7 %) and good agreement with VWF multimer analysis (κ = 0.653). VWF:GPIbM/Ag showed better performance than VWF:CB/Ag. Regarding hematological parameters, there was no difference in hematocrit between patients with and without aVWS. However, leukocyte and platelet counts were significantly increased in the aVWS cohort. CONCLUSION: For the first time, we identified a VWF:GPIbM/Ag ratio of <0.8 as simple screening tool for aVWS in patients with PV or ET. This observation, however, should be confirmed in a larger patient cohort.

Sixth Åland Island Conference on von Willebrand disease.

INTRODUCTION: The sixth Åland Islands Conference on von Willebrand disease (VWD) on the Åland Islands, Finland, was held from 20 to 22 September 2018. AIM: The meeting brought together experts in the field of VWD from around the world to share the latest advances and knowledge in VWD. RESULTS AND DISCUSSION: The topics covered both clinical aspects of disease management, and biochemical and laboratory insights into the disease. The clinical topics discussed included epidemiology, diagnosis and treatment of VWD in different countries, management of children with VWD, bleeding control during surgery, specific considerations for the management of type 3 VWD and bleeding control in women with VWD. Current approaches to the management of acquired von Willebrand syndrome were also discussed. Despite significant advances in the understanding and therapeutic options for VWD, there remain many challenges to be overcome in order to optimise patient care. In comparison with haemophilia A, there are very few registries of VWD patients, which would be a valuable source of data on the condition and its management. VWD is still underdiagnosed, and many patients suffer recurrent or severe bleeding that could be prevented. Awareness of VWD among healthcare practitioners, including non-haematologists, should be improved to allow timely diagnosis and intervention. Diagnosis remains challenging, and the development of fast, simple assays may help to facilitate accurate and rapid diagnosis of VWD.

Safety of intramuscular COVID-19 vaccination in patients with haemophilia.

BACKGROUND: Guidelines recommend that patients with haemophilia should preferably receive vaccination subcutaneously. COVID-19 and other vaccines, however, are only licenced for intramuscular application. AIMS: To assess the safety of intramuscular COVID-19 vaccination in patients living with haemophilia. METHODS: Part A of this prospective observational study enrolled consecutive patients with haemophilia A (HA) and B (HB) of all ages and severities and assessed injection site bleeding and other complications within 30 days of vaccination. Part B enrolled patients providing informed consent for detailed data collection including medication and prophylaxis around the time of vaccination. Logistic regression was performed to assess potential risk factors for bleeding. RESULTS: Four hundred and sixty-one patients were enrolled into part A. The primary endpoint injection site bleeding occurred in seven patients (1.5%, 95% confidence interval .7-3.1%). Comprehensive analysis of 214 patients (404 vaccinations, part B) revealed that 97% of patients with severe haemophilia had prophylaxis before vaccination, either as part of their routine prophylaxis or using additional doses. 56% and 30% of patients with moderate and mild haemophilia, respectively, received prophylaxis before vaccination. Among the seven bleeds recorded, three occurred when intramuscular vaccination was done without prophylaxis (odds ratio 12). CONCLUSIONS: This is the first prospective study reporting on the safety of intramuscular vaccination in haemophilia. The rate of injection site bleeding was low in mild haemophilia, and in moderate and severe haemophilia if patients received factor prophylaxis.

Quality of life in a large multinational haemophilia B cohort (The B-Natural study) - Unmet needs remain.

INTRODUCTION: The B-Natural study is a multicentre, multinational, observational study of haemophilia B (HB) designed to increase understanding of clinical manifestations, treatment and quality of life (QoL). AIM: To characterise and compare QoL in HB across disease severity groups and individuals with inhibitors to identify gaps in treatment. METHODS: A total of 224 individuals from 107 families were enrolled from a total of 24 centres in North America (n = 16), Europe (n = 7) and Asia (n = 1). Of these, 68 (30.4%) subjects had severe (<1 IU/dL), median age 15.6 years, 114 (50.9%) moderate (1-5 IU/dL), age 13.3 years, and 42 (18.8%) mild (>5-< 40 IU/dL), age 12.1 years, disease. Twenty-nine participants had inhibitors or a history of inhibitors. Three versions of the EQ-5D instrument were used as a measure of QoL: proxy (ages 4-7), youth (ages 8-15) and self (age 16+). Each instrument included a visual analogue scale ranging from 100 (best health) to 0 (worst health) to assess current day's health (EQ VAS). Range-of-motion (ROM) for elbows, knees and ankles was assessed using a four-point scale, from which a composite score was calculated. RESULTS: In all severity groups, a proportion of subjects showed less than optimal QoL. The majority of the mild and moderate severe participants reported a normal EQ-5D health profile (79% and 72%, respectively), whereas about half (47%) of the severe participants and only 13% of the inhibitor participants reported this profile. CONCLUSION: The B-Natural study reveals impacted QoL in all disease severities of HB including those with inhibitors. Unmet needs remain and include nonsevere HB.

Electronic diaries in the management of haemophilia gene therapy: Perspective of an expert group from the German, Austrian and Swiss Society on Thrombosis and Haemostasis (GTH).

INTRODUCTION: Gene therapy (GT) is becoming a realistic treatment option for patients with haemophilia. Outside clinical trials, the complexity and potential complications of GT will pose unprecedented challenges to haemophilia care centres. AIM: To explore the potential use of electronic tools to improve the delivery of GT under real-world conditions. METHODS: Considering the hub-and-spoke model, the GTH working group on GT considered the entire patient pathway and reached consensus on requirements for an integrative software tool to secure documenting and sharing information between treaters, pharmacies and patients. RESULTS: Six steps of the gene therapy process were identified, each requiring completion of the previous step as a prerequisite for entry. The responsibilities of GT dosing and follow-up treatment centres, read/write access rules, and the minimum data set were outlined. Data contributed by patients through mobile devices was also considered. CONCLUSION: Important information needs to be shared between patients and treatment centres in a real-world GT hub-and-spoke model. Collecting and sharing this information in well-organised electronic applications will not only improve patient care but also enable national and international data collection in clinical registries.

The Bone Microarchitecture Deficit in Patients with Hemophilia Is Influenced by Arthropathy, Hepatitis C Infection, and Physical Activity.

Low bone mineral density (BMD) is common in patients with hemophilia (PWHs). The aim of the present study was to describe BMD and microarchitecture in PWHs in Northern Germany and to determine factors contributing to possible skeletal alterations. Demographic characteristics, BMD and microarchitecture, bone metabolism markers, and orthopaedic joint score (OJS) were assessed during routine check-ups. Areal BMD was assessed by dual-energy X-ray absorptiometry (DXA) at the hip and lumbar spine. Volumetric BMD and microarchitecture were quantified by high-resolution peripheral quantitative computed tomography at the distal radius and tibia. Eighty male PWHs (median age, 33 years; range, 18-77) were retrospectively analyzed, of whom 67 (84.0%) and 13 (16.0%) had hemophilia A and B, respectively. Fifty-four (68.0%), six (7.0%), and 20 (25.0%) patients had severe, moderate, or mild hemophilia, and 35 (44.0%) were hepatitis C virus (HCV) positive. DXA analysis revealed low BMD (Z-score ≤ - 2.0) in 27.5% of PWHs, and higher bone turnover values were associated with lower BMD. Bone microarchitecture was dominated by cortical deficits at the radius and trabecular deficits at the tibia. Cortical deficits at the radius were influenced by lower body mass index, low-grade inflammation, and treatment regimen (higher cortical thickness on primary prophylaxis). Trabecular alterations at the tibia were mainly associated with OJS and HCV status. A positive effect of self-reported sportive activity on BMD could be shown. In conclusion, our findings demonstrate that the site-specific microarchitectural deficit observed in PWHs is primarily negatively influenced by poor joint status, inflammation, HCV infection, and high bone turnover.

Immune tolerance induction in the era of emicizumab - still the first choice for patients with haemophilia A and inhibitors?

INTRODUCTION: The development of inhibitory antibodies is a severe complication of clotting factor replacement therapy in patients with severe haemophilia A (HA). Current World Federation of Hemophilia (WFH) guidelines for haemophilia care indicate that eradication of inhibitors is best achieved through immune tolerance induction (ITI) therapy. AIM: The European Collaborative Haemophilia Network conducted a survey to determine whether ITI is still used in the routine management of patients with HA, and whether the availability of emicizumab prophylaxis has influenced treatment decisions. METHODS: The survey was conducted in late 2020/early 2021 in 18 centres representing 17 countries in the Europe/Middle East region treating a total of 4955 patients, and included sections specific to patient and centre demographics, treatment protocols (both ITI and prophylactic), inhibitor development and initiation of ITI, treatment success, and the incidence of adverse events. RESULTS: While our results indicate that ITI can still be considered a mainstay of treatment for patients with HA with inhibitors, less than daily dosing of ITI in combination with emicizumab prophylaxis is becoming commonplace across the spectrum of disease severity, with initiation being guided by bleeding patterns. The most frequently cited reasons for not initiating emicizumab prophylaxis were availability or reimbursement issues. CONCLUSION: ITI remains a mainstay for haemophilia treatment of patients with HA with inhibitors, but emicizumab has become a preferred first-line approach to protect against bleeds and represents an alternative to burdensome ITI in certain patient groups.

Clinical and patient reported outcome in total ankle replacement compared to ankle fusion in end-stage haemophilic arthropathy.

BACKGROUND: Ankle arthropathy is a frequent complication of haemophilia, reducing the patients' quality of life. Despite intensive conservative therapy, end-stage arthropathy requires surgical treatment, either by ankle fusion (AF) or total ankle replacement (TAR). METHODS: Eleven consecutive AFs were performed in nine patients and 11 TARs were implemented in 10 patients. Outcomes were assessed clinically by AOFAS score and radiologically by the Pettersson and Gilbert scores. RESULTS: The mean age of the patients in these groups were 35.7 years and 49.4 years, respectively. Of the 11 ankles that underwent fusion, 10 showed bony consolidation not later than 12 weeks after surgery, whereas one still showed non-union after 6 months. VAS pain scores decreased significantly in both groups. Mean AOFAS scores also improved significantly, from 28.1 before to 80.3 after AF and from 21.5 before to 68.0 after ankle replacement. No perioperative complications were observed in either group. Late deep infection was observed in two patients that underwent TAR, which required removal of the implant. CONCLUSION: Our data indicate that both AF and TAR result in significantly reduced pain in patients with haemophilia with end-stage haemophilic arthropathy. While TAR is associated with a higher risk of deep infection and minimal persistent pain, it preserves the pre-operative range of motion. AF on the other hand is associated with the risk of non-union and a longer post-operative recovery period but results in greater pain reduction.

Monocyte activation and acquired autoimmune protein S deficiency promote disseminated intravascular coagulation in a patient with primary antiphospholipid syndrome.

Autoimmune protein S (PS) deficiency is a highly thrombotic, potentially life-threatening disorder. Its pathophysiological relevance in the context of primary antiphospholipid syndrome (APS) is unclear. Here, we report the case of a 76-year-old woman, who presented with a painful reticular skin erythema caused by microvascular thromboses. Disseminated intravascular coagulation (DIC) with consumptive coagulopathy was controlled only by continuous anticoagulation. While significantly elevated IgM antibodies to cardiolipin and ß2-glycoprotein-I were consistent with primary APS, a function-blocking PS autoantibody of the IgG isotype was detected. Robust microvesicle (MV)-associated tissue factor (TF) procoagulant activity (PCA) was isolated from patient plasma. Moreover, patient IgG, but not IgM, induced expression of TF PCA and release of TF-bearing MVs by peripheral blood mononuclear cells from healthy donors. In primary APS, induction of monocyte TF in combination with an acquired PS inhibitor may provoke a deleterious imbalance of procoagulant and anticoagulant pathways with evolution of thrombotic DIC.

The B-Natural study-The outcome of immune tolerance induction therapy in patients with severe haemophilia B.

INTRODUCTION: Inhibitors develop less frequently in haemophilia B (HB) than haemophilia A (HA). However, when present, the success of tolerization by immune tolerance induction (ITI) therapy is lower and the risk of complications higher. AIM: To evaluate the use and outcome of ITI in patients with HB and inhibitors. METHODS: Subjects include singletons or siblings with a current/history of inhibitors enrolled in B-Natural-an observational study designed to increase understanding of clinical management of patients with HB. Patients were followed for 6 months and information on demographics, medical and social history, and treatment were recorded. RESULTS: Twenty-nine patients with severe HB and inhibitors were enrolled in 24 centres. Twenty-two underwent one or more courses of ITI with or without immune suppression. Eight patients (36.4%) were successfully tolerized after the first course of ITI. One of these successes (12.5%) experienced allergic manifestations, whereas the corresponding number for the 10 treatment failures was five (50%). One of seven (14.2%) patients with large deletions and three of eight (37.5%) with nonsense mutations were tolerized at the first attempt, and all patients experiencing nephrosis either failed or were on-going. At study end, 11 (50%) were considered successfully tolerized after one or more ITI courses, three were unsuccessful, and eight were still undergoing treatment. CONCLUSION: Our data underscore the possibilities and difficulties of achieving tolerization in patients with HB with inhibitors. The type of mutation and complications appear to correlate with ITI outcome, but more accurate definitions of successful ITI are warranted.

Consensus Recommendations for Intramuscular COVID-19 Vaccination in Patients with Hemophilia.

BACKGROUND: Currently available coronavirus disease 2019 (COVID-19) vaccines are approved for intramuscular injection and efficacy may not be ensured when given subcutaneously. For years, subcutaneous vaccination was recommended in patients with hemophilia to avoid intramuscular bleeds. Therefore, recommendations for the application of COVID-19 vaccines are needed. METHODS: The Delphi methodology was used to develop consensus recommendations. An initial list of recommendations was prepared by a steering committee and evaluated by 39 hemophilia experts. Consensus was defined as ≥75% agreement and strong consensus as ≥95% agreement, and agreement as a score ≥7 on a scale of 1 to 9. After four rounds, a final list of statements was compiled. RECOMMENDATIONS: Consensus was achieved that COVID-19 vaccines licensed only for intramuscular injection should be administered intramuscularly in hemophilia patients. Prophylactic factor replacement, given on the day of vaccination with a maximum interval between prophylaxis and vaccination of 24 hours (factor VIII and conventional factor IX concentrates) or 48 hours (half-life extended factor IX), should be provided in patients with moderate or severe hemophilia. Strong consensus was achieved that patients with mild hemophilia and residual factor activity greater than 10% with mild bleeding phenotype or patients on emicizumab usually do not need factor replacement before vaccination. Swelling, erythema, and hyperthermia after vaccination are not always signs of bleeding but should prompt consultation of a hemophilia care center. In case of injection-site hematoma, patients should receive replacement therapy until symptoms disappear. CONCLUSIONS: Consensus was achieved on recommendations for intramuscular COVID-19 vaccination after replacement therapy for hemophilia patients depending on disease severity.