Real-world use of recombinant porcine sequence factor VIII in the treatment of acquired hemophilia A: EU PASS.

Background: Recombinant porcine factor VIII (rpFVIII; susoctocog alfa) is indicated for the treatment of bleeding events (BEs) in adults with acquired hemophilia A (AHA). Objectives: To assess the safety, utilization, and effectiveness of rpFVIII in clinical practice. Design: EU post-authorization safety study (PASS) (NCT03199794) was a multicenter, noninterventional, post-authorization safety study conducted in adults with AHA. Methods: Data were collected retrospectively or prospectively for up to 180 days after the last rpFVIII dose. The primary objective was safety, as assessed by adverse events (AEs), serious AEs (SAEs), and AEs of special interest (AESIs) (e.g. immunogenicity, hypersensitivity reactions, thromboembolic events). Secondary endpoints included immunogenicity, rpFVIII hemostatic effectiveness, and rpFVIII utilization. Results: Fifty patients were enrolled; 31 completed the study. The median (range) follow-up for patients who completed or discontinued the study was 178 (26-371) days. The median (range) first dose of rpFVIII was 54.0 (11-200) U/kg. Thirty patients reported 46 SAEs; 5 SAEs were considered probably related to rpFVIII, of which 1 was lack of rpFVIII efficacy, and 4 were AESIs: drug resistance due to FVIII inhibition (one patient), antibody test positive for anti-pFVIII inhibitors (one patient), and de novo anti-pFVIII inhibitors (two patients). No hypersensitivity reactions or thromboembolic events were reported. Of the 50 initial BEs, 37 resolved [in a median (interquartile range) of 8.0 (4.0-16.0) days]. Conclusion: Results from this real-world study support the use of rpFVIII for AHA, aligning with findings from the clinical trial of rpFVIII (NCT01178294) in the treatment of BEs in adults with AHA. Trial registration: EUPAS16055; NCT03199794.

Lack of FVIII detection in humans and dogs with an intron-22 inversion challenges hypothesis regarding inhibitor risk.

BACKGROUND: Almost half of severe hemophilia A (HA) cases are caused by an intron-22 inversion mutation (Int22Inv), which truncates the 26-exon F8 mRNA after exon 22. Another F8 transcript, F8B, is initiated from within F8-intron-22. F8B mRNA consists of a short exon spliced to exons 23-26 and is expressed in multiple human cell types. It has been hypothesized that Int22Inv patients have self-tolerance to partial FVIII proteins expressed from these two transcripts. FVIII is expressed in endothelial cells, primarily in liver and lung. Several studies have reported FVIII expression in other cell types, although this has been controversial. OBJECTIVES: To determine if partial FVIII proteins are expressed from intron 22-inverted and/or F8B mRNA and if FVIII is expressed in non-endothelial cells. METHODS: A panel of FVIII-specific antibodies was validated and employed to label FVIII in cells and tissues, and for immunoprecipitation followed by western blots and mass spectrometry-proteomics analysis. RESULTS: Immunofluorescent (IF) staining localized FVIII to endothelial cells in liver sections from non-HA but not HA-Int22Inv dogs. Neither FVIII nor FVIIIB was detected in human PBMCs, B-cell or T-cell lines, or in cell lines expanded from PBMCs, whereas FVIII antigen and activity were readily detected in primary non-hemophilic liver sinusoidal endothelial cells. CONCLUSIONS: If FVIII is expressed in non-endothelial cells, or if partial FVIII proteins are expressed in HA-Int22Inv, the concentrations are below the detection limits of these sensitive assays. Our results argue against promotion of immune tolerance through expression of partial FVIII proteins in Int-22Inv patients.

Increased Expression Level of Human Blood Clotting Factor VIII Using NS0 Cell Line as a Host Cells.

Background: Coagulation factor VIII (FVIII) is applied for spontaneous hemorrhaging inhibition and excessive bleeding after trauma in patients with hemophilia A. High-quality human recombinant factor VIII (rFVIII) has been produced relatively in large quantities in cultured mammalian cells. NS0 is one of the most common mammalian cell lines for therapeutic protein production. Production of rFVIII has increased due to low FVIII expression levels and rising demand for hemophilia A prophylactic treatment. Several methods have been developed to prevent cell cycle progression in mammalian cells for increased recombinant protein yields. Objective: The aim of the study was to investigate the level of recombinant BDD-FVIII expression in NS0 mouse myeloma cells. Additionally, the study aimed to determine the effects of chemical drugs, Mitomycin C, Lovastatin, and Metformin on the secretion of FVIII through cell cycle arrest. Materials and Methods: We cultured NS0 cells and transfected them with the 2 µg pcDNA3-hBDDFVIII plasmid by Lipofectamine 3000. The cells were treated with 10 µg.mL-1 Mitomycin C, 20 µM Lovastatin, and 20 mM Metformin separately. After 24 and 48 hours, the samples were collected and, protein expression was analyzed using RT-PCR, Dot blot, and ELISA. Results: A higher protein expression level was observed in treated cells 24h and 48h after treatment with all three drugs. According to real-time PCR, Metformin treatment resulted in the highest expression level within 24 h (P=0.0026), followed by Mitomycin C treatment within 48 h (P=0.0030). Conclusion: The NS0 cell line can be regarded as a suitable host for FVIII production. FVIII protein expression level was increased by using Lovastatin, Metformin, and Mitomycin C drugs. Further investigations are suggested, and the potential application of these drugs to increase recombinant protein yield can be used to produce therapeutic proteins in the industry.

Reduce energy consumption in your laboratory - switch ultra-low temperature freezers from - 80 °C to -70 °C. A pilot study on short term storage of plasma samples for coagulation testing.

It is common practice in laboratories to store biological samples in ultra-low temperature (ULT) freezers. There is growing interest in raising the temperature of ULT freezers in order to save energy and reduce expenses, as energy conservation becomes increasingly important and sustainable laboratory practices gain popularity. In our laboratory, plasma samples are stored for three months for diagnostic purposes. We therefore took the opportunity to investigate the effect of two different storage temperatures (-70 °C vs -80 °C), on activated partial thromboplastin time (APTT), factor VIII (FVIII), international normalized ratio (INR) and factor VII (FVII) measurements on paired plasma samples collected from 26 individuals after three months of storage. Automated coagulation analysers CS-5100 and ACL TOP were used to perform the tests. We found no consistent difference between the two storage temperatures for any of the four coagulation parameters (all p-values > 0.05). We conclude that the temperature of ULT freezers used to store plasma samples for APTT, FVIII, INR, and FVII measurements can be safely increased from -80 to -70 °C without affecting the stability of the samples.

Clinical and Humanistic Burden of Non-inhibitor Haemophilia A in Five European Countries: Insights from the CHESS II Study.

INTRODUCTION: Haemophilia A (HA) is a congenital bleeding disorder caused by a deficiency/absence of factor VIII (FVIII) and characterised by frequent, acute and prolonged spontaneous or traumatic bleeding events, often leading to haemophilic arthropathy and progressive joint deterioration. HA severity is characterized by endogenous FVIII activity: mild (> 5-40%), moderate (1-5%), or severe (< 1%). HA poses a substantial clinical and socioeconomic burden on people with HA (PWHA), their caregivers, and society. This analysis evaluates clinical and patient-centric outcomes of a cohort of individuals with non-inhibitor HA sampled from France, Germany, Italy, Spain, and the UK in the 'Cost of Haemophilia in Europe: A Socioeconomic Survey II' (CHESS II) study. METHODS: CHESS II was a cross-sectional burden-of-illness study collecting clinical and socioeconomic data on adult (≥ 18 years) individuals with haemophilia A or B of any severity with or without inhibitors from eight European countries. Descriptive analyses were conducted examining physician-reported demographics, clinical and health resource utilisation information. PWHA-reported health-related quality of life (HRQoL) using the EQ-5D-5L and Work Productivity and Activity Impairment (WPAI) were also examined. Outcomes were stratified by HA severity and reported at country level. RESULTS: Demographics and clinical characteristics of the cohort (N = 880) were generally consistent across countries. Individuals with severe HA experienced more frequent bleeding events and joint disease despite broad use of factor replacement therapy long-term prophylaxis. A minority of those with mild or moderate HA also experienced such challenges. HRQoL and workforce participation diminished, and chronic pain increased, with increasing HA severity. CONCLUSION: This analysis provides up-to-date insights on the impact of HA across five European countries. Increasing HA severity was generally associated with worse clinical outcomes, HRQoL and workforce participation. These findings suggest a place for continued evidence-based tailored treatment and clinical management approaches in addressing the residual burden of HA.

Efficacy and safety of recombinant porcine factor VIII in Japanese patients with acquired hemophilia A.

Acquired hemophilia A (AHA) is a rare bleeding disorder caused by autoantibodies inhibiting human factor VIII (hFVIII). This phase II/III open-label study evaluated the safety and efficacy of recombinant porcine factor VIII (rpFVIII, susoctocog alfa) in adults with AHA and severe bleeding episodes in Japan (NCT04580407). The initial rpFVIII dose was 200 U/kg, with subsequent doses based on clinical measures including plasma FVIII activity. The primary efficacy endpoint was the proportion of severe bleeding episodes with a positive response to rpFVIII therapy 24 h after treatment initiation. Five patients were eligible for, and completed, rpFVIII treatment (age group: 60s-80s; median hFVIII inhibitor: 52 BU/mL; porcine FVIII [pFVIII] inhibitor: 3/5 patients). The median (range) total dose/patient was 548.4 (198-1803) U/kg with a median 3.0 infusions/patient. All patients responded positively to rpFVIII therapy at 24 h regardless of baseline pFVIII inhibitor status. rpFVIII treatment was well tolerated with no adverse events of special interest such as thromboembolic events or de novo pFVIII inhibitors. This study supports the use of rpFVIII as a novel therapy in the clinical management of patients with AHA in Japan. rpFVIII was approved for treating bleeding episodes in adults with AHA in Japan in 2024.

Peripheral Blood Lymphocyte Subsets in Factor VIII Inhibitor-Positive Patients with Severe Hemophilia A: A Case-Control Study.

INTRODUCTION AND OBJECTIVES: The present study aimed to investigate different peripheral lymphocyte subsets in patients with severe hemophilia A (HA) and factor VIII (FVIII) inhibitor production. For this, age-matched cases of 19 FVIII inhibitor-positive (IP), 21 FVIII inhibitor-negative (IN) and 45 healthy controls were selected for study. METHODS: Flow cytometry was used to analyze the peripheral lymphocyte subsets, including T, B, natural killer (NK) and NKT cells. The T cell subsets included CD3 + CD4-CD8- [double negative T (DNT)], CD3 + CD4 + CD8+ [double-positive T (DPT)], CD3 + CD4 + CD8- and CD3 + CD4-CD8+ T cells. Pairwise comparisons of absolute lymphocyte subset values were conducted among the three groups. The cut-off value for absolute lymphocyte counts was determined using receiver operating characteristic curve analysis. RESULTS: The results demonstrated that the absolute values of DPT cells in the IN and IP groups were significantly lower than those in the healthy control group (P = 0.007). The DNT values were also lower in severe HA patients with or without inhibitor than those in healthy subjects, but these differences were not statistically significant (P = 0.053). In addition, the absolute value of CD4+ Th cells in the IP group was lower than that in the healthy controls (P = 0.013). Although not statistically significant (P = 0.064), the absolute values of NKT cells were higher in the IN group compared with the IP group, and higher in the IP group compared with the healthy control group. There were no statistically significant differences in total T, B, CD8 + and NK cells among the IN, IP and healthy control groups. The cut-off value for absolute CD4+ Th cells in the IN group was < 598/µl. CONCLUSION: The decrease in absolute values of CD4+ Th cells in severe HA patients may contribute to the establishment of infused FVIII immune tolerance. If the CD4+ Th value remains > 598/µl, clinicians should be vigilant for possible FVIII inhibitor production, especially on days prior to FVIII exposure.

Activated protein C resistance in the copresence of emicizumab and activated prothrombin complex concentrates.

Background: Venous thromboembolic events have been reported in persons with hemophilia A who received emicizumab and activated prothrombin complex concentrate (APCC) concomitantly, but the relevant mechanism(s) remains unclear. We speculated that activated protein C (APC) and antithrombin (AT) resistance might be associated with these adverse events. Objectives: To investigate APC and AT resistance in factor (F)VIII-deficient (FVIIIdef) plasma in the presence of emicizumab and APCC. Methods: In pooled normal plasma or FVIIIdef plasma samples mixed with emicizumab (50 µg/mL) and FVIII-bypassing agents, including recombinant FVIIa (2.2 µg/mL), APCC (1.3 IU/mL), or plasma-derived FVIIa/FX (1.5 µg/mL), the suppression effect of AT (0-2.4 µM) and APC (0-16 nM) was assessed by tissue factor-triggered thrombin generation assay. The APC effects in FVIIIdef plasma with the copresence of emicizumab, FII (1.3 µM), and/or FIXa (280 pM) were also examined. Results: The AT resistance in emicizumab and each bypassing agent was not observed. Moreover, APC dose-dependent suppression effect was observed in pooled normal plasma or FVIIIdef plasma mixed with emicizumab and recombinant FVIIa or plasma-derived FVIIa/FX. However, APC-catalyzed inactivation had little effect on thrombin generation assay potential in FVIIIdef plasma spiked with emicizumab and APCC. The addition of FIXa to emicizumab in FVIIIdef plasma could lead to partial APC resistance. Furthermore, FVIIIdef plasma spiked with emicizumab, FIXa, and FII was markedly resistant to APC-mediated inactivation. Conclusion: FII and FIXa in APCCs were key clotting factors for APC resistance in FVIIIdef plasma supplemented with emicizumab and APCCs. The APC resistance in persons with hemophilia A receiving emicizumab and APCC may contribute to venous thromboembolic events.

An Electrochemical Biosensor for the Detection of Pulmonary Embolism and Myocardial Infarction.

Due to the clinical similarities between pulmonary embolism (PE) and myocardial infarction (MI), physicians often encounter challenges in promptly distinguishing between them, potentially missing the critical window for the correct emergency response. This paper presents a biosensor, termed the PEMI biosensor, which is designed for the identification and quantitative detection of pulmonary embolism or myocardial infarction. The surface of the working electrode of the PEMI biosensor was modified with graphene oxide and silk fibroin to immobilize the mixture of antibodies. Linear sweep voltammetry was employed to measure the current-to-potential mapping of analytes, with the calculated curvature serving as a judgment index. Experimental results showed that the curvature exhibited a linear correlation with the concentration of antigen FVIII, and a linear inverse correlation with the concentration of antigen cTnI. Given that FVIII and cTnI coexist in humans, the upper and lower limits were determined from the curvatures of a set of normal concentrations of FVIII and cTnI. An analyte with a curvature exceeding the upper limit can be identified as pulmonary embolism, while a curvature falling below the lower limit indicates myocardial infarction. Additionally, the further the curvature deviates from the upper or lower limits, the more severe the condition. The PEMI biosensor can serve as an effective detection platform for physicians.

[Hemophilia: is a revolution in treatment options taking place?] / Hämophilie ­ Revolution der Therapiemöglichkeiten?

Prophylactic replacement therapy for hemophilia A (hereditary factor VIII deficiency) is a success story of the production of coagulation factor concentrates from donor plasma. Recombinant factor concentrates, which are also produced with modified gene constructs for coagulation factor VIII in order to improve pharmacological properties, have since proven their worth. This successful development over many years of factor concentrates for the successful treatment of hemophilia patients has now been followed by the innovation of a factor VIII mimetic in the form of a monoclonal antibody, which was developed in Japan already some years back. Emicizumab is a humanized, bispecific monoclonal antibody for therapeutic use in hemophilia A. With this therapeutic agent, the treatment of the hereditary coagulation defect is based, for the first time, on a completely new active principle. The specific antibody simulates the properties of coagulation factor VIII as a cofactor for the formation of the tenase complex with the coagulation factors IX and X. As a result under steady state conditions almost normal thrombin and thus fibrin formation can be achieved.

Large deletions and small insertions and deletions in the factor VIII gene predict unfavorable immune tolerance induction outcome in people with severe hemophilia A and high-responding inhibitors.

INTRODUCTION: Hemophilia A is an inherited bleeding disorder caused by pathogenic variants in the factor VIII gene (F8), which leads to factor VIII (FVIII) deficiency. Immune tolerance induction (ITI) is a therapeutic approach to eradicate alloantibodies (inhibitors) against exogenous FVIII in people with inherited hemophilia A. Few studies have evaluated the role of F8 variants on ITI outcome. MATERIAL AND METHODS: We included people with severe hemophilia A (FVIII ˂ 1 international units/dL) and high-responding inhibitors (≥ 5 Bethesda units/mL lifelong) who underwent a first course of ITI. Socio-demographic, clinical and laboratory data were collected. ITI outcomes were defined as total, partial successes, and failure. Detection of intron 1 and 22 inversions was performed by polymerase-chain reaction, followed by F8 sequencing. RESULTS: We included 168 people with inherited hemophilia A and high-responding inhibitors, median age 6 years at ITI start. Intron 22 inversion was the most prevalent variant (53.6 %), followed by nonsense (16.1 %), small insertion/deletion (11.3 %), and large deletion (10.7 %). In comparison with intron 22 inversion, the odds of ITI failure were 15.5 times higher (odds ratio [OR] 15.50; 95 % confidence interval [95 % CI] 4.59-71.30) and 4.25 times higher (95 % CI, 1.53-12.3) among carriers of F8 large deletions and small insertions and deletions, respectively. CONCLUSION: F8 large deletions and small insertions/deletions predicted ITI failure after a first course of ITI in patients with severe hemophilia A and high-responding inhibitors. This is the first study to show F8 large deletions and small insertions/deletions as predictors of ITI failure.

A Rare Case of Life-Threatening Hemorrhage.

Acquired hemophilia A is a rare but severe autoimmune bleeding disorder that results from autoantibodies against clotting factor VIII (FVIII). Distinguishing acquired hemophilia from other more common causes of bleeding, such as chronic liver disease, disseminated intravascular coagulation, or sepsis-induced coagulopathies, is crucial in guiding the management of life-threatening hemorrhage. This study describes a patient with primary biliary cholangitis who was found to have acquired hemophilia A, a unique cause of life-threatening bleeding that was especially challenging to diagnose and manage with her underlying liver disease. Identifying acquired hemophilia A allowed an avenue of treatment options that would not have otherwise been available.

Inhibitor development according to concentrate after 50 exposure days in severe hemophilia: data from the European HAemophilia Safety Surveillance (EUHASS).

Background: Patients with hemophilia have a life-long risk of developing neutralizing antibodies (inhibitors) against clotting factor concentrates. After the first 50 exposure days (EDs), ie, in previously treated patients (PTPs), data on inhibitor development are limited. Objectives: To report inhibitor development according to factor (F)VIII or FIX concentrate use in PTPs with severe hemophilia A and B. Methods: Inhibitor development in PTPs was collected since 2008 from 97 centers participating in European HAemophilia Safety Surveillance. Per concentrate, inhibitors were reported quarterly and the number of PTPs treated annually. Incidence rates (IRs)/1000 treatment years with 95% CIs were compared between concentrate types (plasma derived FVIII/FIX, standard half-life recombinant FVIII/FIX, and extended half-life recombinant (EHL-rFVIII/IX) concentrates using IR ratios with CI. Medians and IQRs were calculated for inhibitor characteristics. Results: For severe haemophilia A, inhibitor rate was 66/65,200 treatment years, IR 1.00/1000 years (CI 0.80-1.30), occurring at median 13.5 years (2.7-31.5) and 150 EDs (80-773). IR on plasma-derived pdFVIII (IR, 1.13) and standard half-life recombinant FVIII (IR, 1.12) were similar, whereas IR on EHL-rFVIII was lower at 0.13 (incidence rate ratio, 0.12; 95% CI, <0.01-0.70; P < .01).For severe hemophilia B, inhibitor rate was 5/11,160 treatment years and IR was 0.45/1000 years (95% CI, 0.15-1.04), at median 3.7 years (95% CI, 2.1-42.4) and 260 EDs (95% CI, 130 to >1000). Data were insufficient to compare by type of FIX concentrates. Conclusion: Low inhibitor rates were observed for PTPs with severe hemophilia A and B. Data suggested reduced inhibitor development on EHL-rFVIII, but no significant difference between plasma-derived FVIII and standard half-life recombinant FVIII. FIX inhibitor rates were too low for robust statistical analysis.

Reconstruction of the historic time course of blood-borne virus contamination of clotting factor concentrates, 1974-1992.

Factor VIII and IX clotting factor concentrates manufactured from pooled plasma have been identified as potent sources of virus infection in persons with hemophilia (PWHs) in the 1970s and 1980s. To investigate the range and diversity of viruses over this period, we analysed 24 clotting factor concentrates for several blood-borne viruses. Nucleic acid was extracted from 14 commercially produced clotting factors and 10 from nonremunerated donors, preserved in lyophilized form (expiry dates: 1974-1992). Clotting factors were tested by commercial and in-house quantitative PCRs for blood-borne viruses hepatitis A, B, C and E viruses (HAV, HBV, HCV, HEV), HIV- types 1/2, parvoviruses B19V and PARV4, and human pegiviruses types 1 and 2 (HPgV-1,-2). HCV and HPgV-1 were the most frequently detected viruses (both 14/24 tested) primarily in commercial clotting factors, with frequently extremely high viral loads in the late 1970s-1985 and a diverse range of HCV genotypes. Detection frequencies sharply declined following introduction of virus inactivation. HIV-1, HBV, and HAV were less frequently detected (3/24, 1/24, and 1/24 respectively); none were positive for HEV. Contrastingly, B19V and PARV4 were detected throughout the study period, even after introduction of dry heat treatment, consistent with ongoing documented transmission to PWHs into the early 1990s. While hemophilia treatment is now largely based on recombinant factor VIII/IX in the UK and elsewhere, the comprehensive screen of historical plasma-derived clotting factors reveals extensive exposure of PWHs to blood-borne viruses throughout 1970s-early 1990s, and the epidemiological and manufacturing parameters that influenced clotting factor contamination.

A Rare Case of Acquired Factor VIII Inhibition in an Elderly Female.

Acquired hemophilia A is a rare condition characterized by the development of autoantibodies against coagulation factor VIII. It often initially presents as serious bleeding in the absence of risk factors and carries high morbidity and mortality if not diagnosed early. Due to its rare nature, data is limited, and guidelines are primarily based on expert opinion. Here we present a case of an elderly patient with severe gastrointestinal bleeding found to have activated partial thromboplastin times, plasma mixing studies, and coagulation factor activity levels consistent with acquired hemophilia A. We hope to bring awareness of this rare disease and promote its consideration in the differential of unexpected bleeding to improve safety outcomes.

Valoctocogene roxaparvovec gene therapy provides durable haemostatic control for up to 7 years for haemophilia A.

INTRODUCTION: Valoctocogene roxaparvovec is an adeno-associated virus vector serotype 5 (AAV5)-mediated gene therapy approved for severe haemophilia A (HA). AIM: To report the safety and efficacy of valoctocogene roxaparvovec 7 years after dosing in a phase 1/2 clinical study (NCT02576795). METHODS: Males ≥18 years with severe HA (factor VIII [FVIII] ≤1 international unit [IU]/dL) who were previously receiving exogenous FVIII and had no history of FVIII inhibitors or anti-AAV5 antibodies received valoctocogene roxaparvovec treatment and were followed for 7 (6 × 1013 vg/kg; n = 7) and 6 (4 × 1013 vg/kg; n = 6) years. RESULTS: In the last year, one participant in each cohort reported treatment-related adverse events (AEs): grade 1 (G1) hepatomegaly (6 × 1013), and G1 splenomegaly and G1 hepatic steatosis (4 × 1013). During all follow-up, mean annualized treated bleeds and exogenous FVIII infusion rates were ≥88% lower than baseline values. At years 7 and 6, mean (median) FVIII activity (chromogenic assay) was 16.2 (10.3) and 6.7 (7.2) IU/dL in the 6 × 1013 (n = 5) and 4 × 1013 (n = 4) cohorts, respectively, corresponding to mild haemophilia. Regression analyses of the last year estimated rate of change in FVIII activity was -0.001 and -0.07 IU/dL/week for the 6 × 1013 and 4 × 1013 cohorts, respectively. Two participants (6 × 1013) resumed prophylaxis in year 7: one after a non-treatment-related G4 serious AE of spontaneous internal carotid artery bleed, and the other to manage bleeds and FVIII activity. CONCLUSIONS: The safety and efficacy of valoctocogene roxaparvovec remain generally consistent with previous reports, with good haemostatic control for most participants. Two participants returned to prophylaxis.

Bleeding Mystery Unveiled: A Case of Acquired Hemophilia A in the Shadow of Multiple Myeloma.

This case report is of a 50-year-old woman who had a working diagnosis of von Willebrand disease (vWD) due to a history of bleeding complications and continued to experience recurrent bleeding incidents and hematoma. A workup revealed multiple lytic lesions, and a bone marrow biopsy yielded the diagnosis of multiple myeloma. After stem cell transplantation, the patient's factor VIII levels normalized, supporting acquired factor VIII deficiency due to an autoimmune phenomenon. This case highlights the rare occurrence of acquired factor VIII deficiency secondary to multiple myeloma. It also emphasizes the importance of considering secondary causes in patients with a working diagnosis of vWD and recurrent bleeding incidents.

Anti-mCD20 in combination with α-mCXCL13 monoclonal antibody inhibits anti-FVIII antibody development in hemophilia A mice.

Anti-factor VIII (FVIII) antibody development poses a significant challenge in hemophilia A (HA) patients receiving FVIII protein replacement therapy. There is an urgent need for novel therapeutic strategies to inhibit the production of anti-FVIII inhibitory antibodies (inhibitors) in HA. This study aimed to investigate a combination monoclonal antibody (mAb) therapy targeting CXCL13 and CD20 on the development of anti-FVIII antibodies in a HA murine model, along with the underlying mechanisms involved. Specifically, mAbs targeting mouse CD20 (18B12) with an IgG2a backbone and mouse CXCL13 (2C4) with an IgG1 backbone were synthesized. HA mice with FVIII inhibitors were established, and the results revealed that the combination therapy of anti-mCD20 with α-mCXCL13 significantly suppressed anti-FVIII antibody development and induced FVIII tolerance. Furthermore, this combination therapy led to a marked reduction of peripheral and splenic follicular helper T cells and an enhancement of regulatory T cell induction, along with sustained depletion of bone marrow and splenic plasma cells in HA mice with preexisting FVIII immunity. Thus, the concurrence of blockage of CD20 and neutralization of CXCL13 hold promise as a therapeutic strategy for HA patients with inhibitors.

Factor VIII Levels and ISTH Disseminated Intravascular Coagulation Scores Do Not Distinguish Disseminated Intravascular Coagulation from the Coagulopathy of Liver Disease.

INTRODUCTION: Distinguishing disseminated intravascular coagulation (DIC) from the coagulopathy of liver disease represents a common clinical challenge. Here, we evaluated the utility of two diagnostic tools frequently used to differentiate between these conditions: factor VIII (FVIII) levels and the International Society on Thrombosis and Hemostasis (ISTH) DIC score. METHODS: To this end, we conducted a retrospective chart review of patients with DIC, liver disease, or both. Multiple logistic regression was performed, and receiver operating characteristic curves were generated to calculate the area under curve (AUC) for distinguishing DIC in the setting of liver disease. RESULTS: Among 123 patients with DIC, liver disease, or liver disease plus DIC, FVIII levels did not differ significantly. ISTH scores were lower in patients with DIC than in liver disease with or without DIC. Addition of several laboratory parameters to the ISTH score, including mean platelet volume, FV, FVIII, international normalized ratio, and activated partial thromboplastin time, improved AUC for distinguishing DIC in liver disease from liver disease alone (AUC = 0.76; p < 0.0001). CONCLUSION: We conclude that FVIII levels do not distinguish DIC from liver disease, and ISTH DIC scores are not predictive of DIC in patients with liver disease. Inclusion of additional lab variables within the ISTH DIC score may aid in identifying DIC in patients with liver disease.