BACKGROUND:An earlier analysis of the "My Life, Our Future" Repository indicated the risk of individuals with severe hemophilia A (HA) developing neutralizing antifactor (F)VIII antibodies (inhibitors) was (1) higher in Black and Hispanic cohorts and (2) similar in intron-22 inversion mutations vs other large structural changes in the F8 gene. OBJECTIVES:This study determined whether specific human leukocyte antigen (HLA) alleles or haplotypes indicate either risk of or protection from inhibitor development in severe HA and if such associations correlate with race/ethnicity or F8 variant type. METHODS:HLA haplotypes were obtained from whole genome sequence data for 1841 subjects with severe HA and their racial/ethnic categories verified by principal component analysis. Pairwise and multivariable logistic regression analyses were performed for subcohorts of HLA alleles/haplotypes defined by HA mutation type and race/ethnicity. RESULTS:HLA-DRB1∗15:01, DQB1∗06:02, and DQA1∗01:02 and B∗07:02 were higher-risk alleles for the White/non-Hispanic cohort, while HLA-DRB∗14:01, DQB1∗05:03, DQB1∗03:01, B∗38:01, B∗44:02, and C∗05:01 were lower-risk alleles. HLA-B∗15:03 and B∗58:01 were higher-risk alleles for the Black/non-Hispanic cohort, while HLA-A∗33:03 was a lower-risk allele. Additional alleles were associated with inhibitor risk across the following cohorts: all (N = 1841), intron-22 inversion (n = 836), missense (n = 288), not-missense (n = 1553). No associations of HLA with inhibitor risk were seen for the Hispanic/White cohort. Analysis of subjects carrying both higher-risk and lower-risk alleles revealed combinations affecting the risks associated with individual alleles. CONCLUSION:Our results implicate both innate and adaptive immune mechanisms, possibly including multiallelic HLA-associated effects on FVIII processing/presentation or signaling pathways in the development of inhibitors vs peripheral tolerance to FVIII.

BACKGROUND:Extracorporeal life support (ECLS) can cause bleeding via excessive cleavage of multimeric protein von Willebrand Factor (VWF) by protease ADAMTS-13, a bleeding diathesis termed acquired von Willebrand syndrome. VWF high-molecular-weight multimers (HMWM) are more procoagulant than smaller multimers. Acute-phase responses generate high levels of VWF-HMWM and reduced ADAMTS-13 activity. OBJECTIVES:Assess whether VWF-HMWM degradation is less pronounced and VWF:collagen binding activity (CB)/VWF:antigen (Ag) ratios are lower during ECLS in acute trauma vs noninjury settings. METHODS:Anesthetized, mechanically ventilated swine (45-60 kg) were randomized to polytrauma (INJ CTRL, n = 14) managed with mechanical ventilation, uninjured receiving veno-venous extracorporeal carbon dioxide removal (ECLS CTRL, n = 20), or polytrauma managed with extracorporeal carbon dioxide removal (ECLS INJ, n = 22). In ECLS groups, 50% of animals received heparin anticoagulation, while 50% received no systemic anticoagulation. VWF:Ag, VWF:CB, VWF multimer size distribution, and ADAMTS-13 activity were evaluated at baseline, post-injury/intervention, and at 6, 24, 48, and 72 hours. RESULTS:VWF-HMWM were depleted at 72 hours in ECLS CTRL (-19 ± 3%, P < .0001), but not in ECLS INJ (-10 ± 5%, P = .09). VWF:CB/VWF:Ag ratios relative to baseline were reduced at 48 to 72 hours in ECLS CTRL (0.84 ± 0.04, P = .002) and ECLS INJ (0.69 ± 0.05, P < .001) but not INJ CTRL. ADAMTS-13 activity decreased in all groups. Animals treated with heparin showed less pronounced VWF-HMWM degradation, higher VWF:CB/VWF:Ag ratios, and higher ADAMTS-13 activity vs matched non-anticoagulated animals. CONCLUSION:Trauma managed with ECLS was associated with reduced VWF:CB/VWF:Ag ratios and lower ADAMTS-13 activity, but VWF-HMWM depletion was minimal. Thus, potential for acquired von Willebrand syndrome is a concern for trauma patients undergoing ECLS. Heparin partially countered effects of ECLS on VWF and ADAMTS-13.

BackgroundSignificant clinical similarities have been observed between the recently described “Long-Haul” COVID-19 (LHC) syndrome, Postural Orthostatic Tachycardia Syndrome (POTS) and Inappropriate Sinus Tachycardia (IST). Shared symptoms include light-headedness, palpitations, tremulousness, generalized weakness, blurred vision, chest pain, dyspnea, “brain-fog,” and fatigue. Ivabradine is a selective sinoatrial node blocker FDA-approved for management of tachycardia associated with stable angina and heart failure not fully managed by beta blockers. In our study we aim to identify risk factors underlying LHC, as well as the effectiveness of ivabradine in controlling heart rate dysregulations and POTS/IST related symptoms.Methods/designA detailed prospective phenotypic evaluation combined with multi-omic analysis of 200 LHC volunteers will be conducted to identify risk factors for autonomic dysfunction. A comparator group of 50 volunteers with documented COVID-19 but without LHC will be enrolled to better understand the risk factors for LHC and autonomic dysfunction. Those in the cohort who meet diagnostic criteria for POTS or IST will be included in a nested prospective, randomized, placebo-controlled trial to assess the impact of ivabradine on symptoms and heart rate, assessed non-invasively based on physiologic response and ambulatory electrocardiogram. Additionally, studies on catecholamine production, mast cell and basophil degranulation, inflammatory biomarkers, and indicators of metabolic dysfunction will be measured to potentially provide molecular classification and mechanistic insights.DiscussionOptimal therapies for dysautonomia, particularly associated with LHC, have yet to be defined. In the present study, ivabradine, one of numerous proposed interventions, will be systematically evaluated for therapeutic potential in LHC-associated POTS and IST. Additionally, this study will further refine the characteristics of the LHC-associated POTS/IST phenotype, genotype and transcriptional profile, including immunologic and multi-omic analysis of persistent immune activation and dysregulation. The study will also explore and identify potential endotheliopathy and abnormalities of the clotting cascade.Clinical trial registrationhttps://clinicaltrials.gov/, identifier NCT05481177.

BACKGROUND:Development of neutralizing anti-factor [F]VIII antibodies (inhibitors) follows recognition by CD4+ T cells of epitopes that are presented on the individual's human leukocyte antigen (HLA) class II. Limited blood volumes have presented a major challenge in mapping T-cell epitopes in FVIII, especially as these immune responses typically develop in early childhood. OBJECTIVES:To determine whether CD4+ T cells from individuals with and without hemophilia A (HA) respond to the same T-cell epitopes. METHODS:We used interferon-γ enzyme-linked immunospot (ELISPOT) assays with added costimulation to test both unmanipulated CD4+ T cells and in vitro-expanded FVIII-specific CD4+ T-cell lines from donors without HA, to identify responses to FVIII protein and to synthetic 15-mer FVIII peptides. RESULTS:Tests of both unmanipulated and in vitro-expanded CD4+ T-cell populations from donors without HA identified immunodominant epitopes in FVIII. However, the protocol using expanded T-cell lines produced higher background interferon-γ secretion, which could mask responses to some FVIII epitopes. Importantly, several HLA-DRB1-restricted epitopes identified using T cells from subjects without HA were reproducibly found using T cells from subjects with HA who carried the same HLA-DRB1 alleles. CONCLUSION:Circulating non-HA CD4+ T cells with self-FVIII specificity, i.e, cells that apparently escaped thymic editing, can respond to the same epitopes recognized by CD4+ T cells from individuals with HA. Therefore, costimulation-enhanced ELISPOT assays can identify clinically relevant T-cell epitopes in FVIII using blood from healthy donors without HA, thereby overcoming blood volume limitations inherent to pediatric patient populations.

Introduction: Novel hemoperfusion systems are emerging for the treatment of sepsis. These devices can directly remove pathogens, pathogen-associated molecular patterns, cytokines, and other inflammatory markers from circulation. However, significant safety concerns such as potential antibiotic clearance need to be addressed prior to these devices being used in large clinical studies. Methods: Prospective, observational study of 34 participants undergoing treatment with the Seraph 100 (R) Microbind Affinity Blood Filter (Seraph 100) device at 6 participating sites in the USA. Patients were included for analysis if they had a record of receiving an antibiotic concurrent with Seraph 100 treatment. Patients were excluded if there was missing information for blood flow rate. Blood samples were drawn pre- and post-filter at 1 h and 4 h after treatment initiation. These average pre- and post-filter time-concentration observations were then used to estimate antibiotic clearance in L/h (CLSeraph) due to the Seraph 100 device. Results: Of the 34 participants in the study, 17 met inclusion and exclusion criteria for the antibiotic analysis. Data were obtained for 7 antibiotics (azithromycin, cefazolin, cefepime, ceftriaxone, linezolid, piperacillin, and vancomycin) and one beta-lactamase inhibitor. Mean CLSeraph for the antibiotics investigated ranged from -0.57 to 0.47 L/h. No antibiotic had a CLSeraph statistically significant from 0. Discussion/Conclusion: The Seraph 100 did not significantly clear any measured antibiotic in clinical samples. These data give further evidence to suggest that these therapies may be safely administered to critically ill patients and will not impact concentrations of administered antibiotics.

Introduction: We report an Intervention/outcome study of 33 severe COVID-19 subjects who received Seraph 100 Microbind Affinity Blood Filter (Seraph 100) hemoperfusion therapy (15 survivors, 18 non-survivors) under emergency authorization from the FDA. Our objective was to determine if Seraph 100 hemoperfusion reduces SARS-CoV-2 RNA titers and/or markers of inflammation and/or epi/endothelial damage. Methods: Viral RNA and 78 protein analytes related to endothelial/epithelial damage and/or inflammation were quantified in systemic blood samples from 33 severe COVID-19 subjects collected upon intensive care unit (ICU) admission and then immediately before and after blood passed through the heparin-based Seraph 100 filter at two time points on the first day of hemoperfusion. Viral RNA titers were quantified using droplet digital PCR. Protein analytes were quantified using multiplex/multianalyte panels on MesoScale Discovery and ProteinSimple Ella platforms. Results: A total of 15/33 subjects had detectable viral RNA in baseline samples (shortly after ICU admission). These initial viremia levels were low, and they did not change uniformly post-perfusion. Five of 55 protein analytes that were upregulated 1.4-120X at ICU admission relative to healthy controls showed significant decreases across the filter during the indicated time points on the first day of hemoperfusion: IP-10/CXCL10, fms-like tyrosine kinase 1, MIG/CXCL9, hepatocyte growth factor (HGF), and receptor for advanced glycosylation end products (RAGE). Paired t tests identified 25 additional analytes that showed significant decreases (p < 0.05) only without Bonferroni correction. Conclusion: Initial freely circulating SARS-CoV-2 RNA levels of ICU-admitted subjects were low or undetectable. The Seraph 100 filter did not significantly reduce viral RNA titers in their plasma. However, multiple circulating proteins with roles in inflammation, endothelial/ epithelial damage, and/or angiogenesis decreased significantly across the filter. Larger prospective trials will be required to determine if such transient reductions translate into improved patient outcomes. However, this study did not demonstrate a direct reduction of free SARS-CoV-2 viral RNA by the Seraph 100. (c) 2024 S. Karger AG, Basel

BACKGROUND:Almost half of severe hemophilia A (HA) cases are caused by an intron 22 inversion (Int22Inv) mutation, which truncates the 26-exon F8 messenger RNA (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 to 26 and is expressed in multiple human cell types. It has been hypothesized that Int22Inv patients have self-tolerance to partial factor (F)VIII proteins expressed from these 2 transcripts. FVIII is expressed in endothelial cells, primarily in the liver and lungs. 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 nonendothelial 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 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 peripheral blood mononuclear cells, B cell or T cell lines, or cell lines expanded from peripheral blood mononuclear cells, whereas FVIII antigen and activity were readily detected in primary nonhemophilic liver sinusoidal endothelial cells. CONCLUSION:If FVIII is expressed in nonendothelial 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.

PURIFY-OBS-1 is an observational study evaluating the safety and efficacy of Seraph 100® Microbind Affinity Blood Filter (Seraph 100) use for COVID-19 patients with respiratory failure admitted to the intensive care unit (ICU). The Seraph 100 is a hemoperfusion device containing heparin-coated beads that can bind to, and reduce levels of, some circulating pathogens and inflammatory molecules. This study evaluated whether treatment with the Seraph 100 affected circulating and mucosal antibody levels in critically ill COVID-19 subjects. SARS-CoV-2 anti-spike and anti-nucleocapsid IgG and IgA levels in serum were evaluated at enrollment and on days 1, 4, 7, and 28 after Seraph 100 application, while anti-spike and nucleocapsid IgG, IgA, and secretory IgA levels in tracheal aspirates were evaluated at enrollment and on days 1, 2, 3, 7, and 28. Serum samples were also collected from the pre- and post-filter lines at 1 and 4 h following Seraph 100 application to evaluate the direct impact of the filter on circulating antibody levels. Treatment with the Seraph 100 did not alter the levels of circulating or mucosal antibodies in critically ill COVID-19 subjects admitted to the ICU.

The most common complication in hemophilia A (HA) treatment, affecting 25% to 30% of patients with severe HA, is the development of alloimmune inhibitors that foreclose the ability of infused factor VIII (FVIII) to participate in coagulation. Inhibitors confer significant pathology on affected individuals and present major complexities in their management. Inhibitors are more common in African American patients, and it has been hypothesized that this is a consequence of haplotype (H)-treatment product mismatch. F8 haplotypes H1 to H5 are defined by nonsynonymous single-nucleotide polymorphisms encoding sequence variations at FVIII residues 1241, 2238, and 484. Haplotypes H2 to H5 are more prevalent in individuals with Black African ancestry, whereas 80% to 90% of the White population has the H1 haplotype. This study used an established multiplex fluorescence immunoassay to determine anti-FVIII antibody titers in plasma from 394 individuals with HA (188 Black, 206 White), measuring their binding to recombinant full-length H1 and H2 and B-domain-deleted (BDD) H1/H2, H3/H5, and H4 FVIII proteins. Inhibitor titers were determined using a chromogenic assay and linear B-cell epitopes characterized using peptide microarrays. FVIII-reactive antibodies were readily detected in most individuals with HA, with higher titers in those with a current inhibitor, as expected. Neither total nor inhibitory antibody titers correlated with F8 haplotype mismatches, and peptides with D1241E and M2238V polymorphisms did not comprise linear B-cell epitopes. Interestingly, compared with the full-length FVIII products, the BDD-FVIII proteins were markedly more reactive with plasma antibodies. The stronger immunoreactivity of BDD-FVIII suggests that B-domain removal might expose novel B-cell epitopes, perhaps through conformational rearrangements of FVIII domains.

Abstract Background Autoimmune responses to self-FVIII can cause a rare but potentially life-threatening autoimmune bleeding disorder referred to as “acquired hemophilia A”. Objectives (1) To confirm the frequency and specificity of CD4 T cells recognizing factor (F)VIII in the periphery of non-hemophilic individuals; (2) to improve methodology for detecting rare self-reactive CD4 T cells that apparently escaped thymic editing. Methods CD4 T cells were isolated from healthy non-hemophilic blood donors, incubated with autologous irradiated PBMCs, and stimulated with FVIII 15-mer peptides, anti-CD28 and anti-CD49D. Positive interferon-gamma ELISPOT responses were detected, but they were poorly reproducible due to the low frequency of these autoreactive cells. Therefore, pre-expansion of FVIII-specific T-cell lines, followed by ELISPOT assays with added co-stimulation, was carried out to increase sensitivity and accuracy. Results Several immunodominant epitopes in FVIII restricted to H LA-DRB1* 01:01, 07:01 and 15:01 were identified. FVIII-specific T-cell lines generated from individual blood donors showed robust interferon-gamma secretion in response to FVIII, compared to ELISPOT assays with co-stimulation but no FVIII pre-expansion. Conclusions Our optimized protocol, involving generation of antigen-specific T-cell lines followed by ELISPOTs with added co-stimulation, shows promise for detecting, quantifying and characterizing rare autoreactive T cells in the periphery. Intramural funds, Uniformed Services University

The authors regret the need to update the acknowledgements and change the below paragraphs as follows: Original Introduction, paragraph 3: The "My Life Our Future" (MLOF) Research Repository is the result of a collaboration between the hemophilia community in the United States, their respective hemophilia treatment centers (HTCs), the Bloodworks Northwest Research Institute (BWNW), and the American Thrombosis and Hemostasis Network (ATHN), carried out with initial funding from Biogen (now Bioverativ/Sanofi, Inc) [4,5]. Under this program, individuals were able to submit (through their HTC) a blood sample, from which DNA was extracted and analyzed to determine whether the participant carried a genetic mutation associated with a bleeding disorder, e.g., hemophilia A or B, von Willebrand disease, etc. Participation in research by donating DNA and plasma fractions of these blood samples and making their clinically relevant data available to researchers was offered, but not required, as part of this initiative. Through a competitive application process, access to the MLOF and ATHN databases was granted to several research groups, each of which proposed research questions that could be uniquely addressed using data and/or samples from this Repository. The ATHN/MLOF Repository currently contains the largest dataset in the world containing F8 DNA sequences linked to clinical data for HA subjects. Revised Introduction, paragraph 3: The "My Life Our Future" (MLOF) Research Repository is the result of a collaboration between the hemophilia community in the United States, their respective hemophilia treatment centers (HTCs), Bloodworks Northwest (BWNW), the National Hemophilia Foundation, and the American Thrombosis and Hemostasis Network (ATHN), carried out with initial funding from Biogen/Bioverativ [4,5]. Under this program, individuals were able to submit (through their HTC) a blood sample, from which DNA was extracted and analyzed to determine whether the participant carried a genetic variant associated with hemophilia A or B. Participation in research by donating DNA and blood samples and making their clinically relevant data available to researchers was offered, but not required, as part of this initiative. Through a competitive application process, access to the MLOF and ATHN databases was granted to several research groups, each of which proposed research questions that could be uniquely addressed using data and/or samples from this Repository. The ATHN/MLOF Repository currently contains the largest dataset in the world containing F8 DNA sequences linked to clinical data for HA subjects. Original Acknowledgments: We are grateful to the My Life Our Future Executive Committee that approved this project and to ATHN for providing the data. Special thanks to Ms Shelley Fletcher and Dr Jill Johnsen (BWNW) for assistance with data cleaning of the original ATHN/MLOF datasets. Revised Acknowledgments: The My Life, Our Future Research Repository is a collection of genetic and phenotypic data and samples developed from the My Life, Our Future (MLOF) national genotyping program, which was a partnership with the American Thrombosis Hemostasis Network, Bloodworks Northwest, and the National Hemophilia Foundation with financial support from Biogen/Bioverativ. The MLOF Research Repository was established through engagement with the blood disorders community to co-create a repository of genotypic data about people with hemophilia, which can be used to support research. More than 9,000 participants in MLOF consented to contribute their genetic data and biological samples to create the MLOF Research Repository. The MLOF Research Repository acknowledges the dedicated efforts all of the participants in MLOF, and the hemophilia treatment centers for their significant contributions to the MLOF Research Repository. Special thanks to Ms Shelley Fletcher and Dr Jill Johnsen (BWNW) for assistance with data cleaning of the original ATHN/MLOF datasets. The MLOF Research Repository has received financial support from the American Thrombosis and Hemostasis Network, the National Hemophilia Foundation, Bloodworks Northwest, the Washington Center for Bleeding Disorders, and Sanofi. The content of this manuscript is solely the responsibility of the authors and does not necessarily represent the views of the My Life, Our Future Research Repository project, or its partners. The authors would like to apologise for any inconvenience caused. Race, ethnicity, F8 variants, and inhibitor risk: analysis of the "My Life Our Future" hemophilia A databaseJournal of Thrombosis and HaemostasisVol. 21Issue 4PreviewSeveral studies have suggested Black and Hispanic hemophilia A (HA) patients in the United States suffer higher incidences of neutralizing anti-FVIII antibodies (inhibitors) than their White counterparts. The possible influence of nonsynonymous single-nucleotide polymorphisms (ns-SNPs) in the F8 gene sequence has been proposed as a possible race-associated contributing factor. Some earlier studies indicated that intron-22 inversion mutations carry a lower inhibitor risk than other mutations resulting in large F8 gene disruptions. Full-Text PDF

Background Almost half of severe hemophilia A (HA) is caused by an intron 22 inversion mutation (Int22Inv), which disrupts the 26-exon F8 gene. Inverted F8 mRNA exons 1-22 are transcribed, while F8B mRNA, containing F8 exons 23-26, is transcribed from a promoter within intron 22. Neither FVIII activity nor FVIII antigen (cross-reacting material, CRM) are detectable in plasma of patients with an intron-22 inversion. Objectives To test the hypothesis that (putative) intracellular synthesis of FVIII proteins encoded by inverted F8 and F8B mRNAs confers T-cell tolerance to almost the entire FVIII sequence, and to evaluate the immunogenicity of the region encoded by the F8 exon 22-23 junction sequence. Patients/Methods Peripheral blood mononuclear cells (PBMCs) from 30 severe or moderate HA subjects (17 with an Int22Inv mutation) were tested by ELISPOT assays to detect cytokine secretion in response to FVIII proteins and peptides and to map immunodominant T-cell epitopes. Potential immunogenicity of FVIII sequences encoded by the F8 exon 22-23 junction region was also tested using peptide-MHCII binding assays. Results Eight of the Int22Inv subjects showed robust cytokine secretion from PBMCs stimulated with FVIII proteins and/or peptides, consistent with earlier publications from the Conti-Fine group. Peptide ELISPOT assays identified immunogenic regions of FVIII. Specificity for sequences encoded within F8 mRNA exons 1-22 and F8B mRNA was confirmed by staining Int22Inv CD4+ T cells with peptide-loaded HLA-Class II tetramers. FVIII peptides spanning the F8 exon 22-23 junction (encoding M2124-V2125) showed limited binding to MHCII proteins and low immunogenicity, with cytokine secretion from only one Int22Inv subject. Conclusions PBMCs from multiple subjects with an Int22Inv mutation, with and without a current FVIII inhibitor, responded to FVIII epitopes. Furthermore, the FVIII region encoded by the exon 22-23 junction sequence was not remarkably immunoreactive and is therefore unlikely to contain an immunodominant, promiscuous CD4+ T-cell epitope. Our results indicate that putative intracellular expression of partial FVIII proteins does not confer T-cell tolerance to FVIII regions encoded by inverted F8 mRNA or F8B mRNA.

problematic. 4That should not stop us from developing and testing more potent and selective STAT5B inhibitors, as kinase inhibitors were initially also received with skepticism.

OBJECTIVES:. The Seraph100 Microbind Affinity Blood Filter (Seraph 100) (ExThera Medical, Martinez, CA) is an extracorporeal therapy that can remove pathogens from blood, including severe acute respiratory syndrome coronavirus 2. The aim of this study was to evaluate safety and efficacy of Seraph 100 treatment for COVID-19. DESIGN:. Retrospective cohort study. SETTING:. Nine participating ICUs. PATIENTS:. COVID-19 patients treated with Seraph 100 (n = 53) and control patients matched by study site (n = 53). INTERVENTION:. Treatment with Seraph 100. MEASUREMENTS AND MAIN RESULTS:. At baseline, there were no differences between the groups in terms of sex, race/ethnicity, body mass index, and need for mechanical ventilation. However, patients in the Seraph 100 group were younger (median age, 54 yr; interquartile range [IQR], 41–65) compared with controls (median age, 64 yr; IQR, 56–69; p = 0.009). Charlson comorbidity index scores were lower in the Seraph 100 group (2; IQR, 0–3) compared with the control group (3; IQR, 2–4; p = 0.006). Acute Physiology and Chronic Health Evaluation II scores were also lower in Seraph 100 subjects (12; IQR, 9–17) compared with controls (16; IQR, 12–21; p = 0.011). The Seraph 100 group had higher vasopressor-free days with an incidence rate ratio of 1.30 on univariate analysis. This difference was not significant after adjustment. Seraph 100-treated subjects were less likely to die compared with controls (32.1% vs 64.2%; p = 0.001), a difference that remained significant after adjustment. However, no difference in mortality was observed in a post hoc analysis utilizing an external control group. In the full cohort of 86 treated patients, there were 177 total treatments, in which only three serious adverse events were recorded. CONCLUSIONS:. Although this study did not demonstrate consistently significant clinical benefit across all endpoints and comparisons, the findings suggest that broad spectrum, pathogen agnostic, blood purification can be safely deployed to meet new pathogen threats while awaiting targeted therapies and vaccines.

BACKGROUND:Several studies have suggested Black and Hispanic hemophilia A (HA) patients in the United States suffer higher incidences of neutralizing anti-FVIII antibodies (inhibitors) than their White counterparts. The possible influence of nonsynonymous single-nucleotide polymorphisms (ns-SNPs) in the F8 gene sequence has been proposed as a possible race-associated contributing factor. Some earlier studies indicated that intron-22 inversion mutations carry a lower inhibitor risk than other mutations resulting in large F8 gene disruptions. OBJECTIVES:The objectives of the study were to test the following hypotheses: (1) The risk of developing an inhibitor differs among racial/ethnic groups in the United States, (2) specific non-HA-causing ns-SNPs in the F8 gene are correlated with inhibitor risk, and (3) inhibitor risk associated with intron-22 inversions mutations is similar to that associated with other large structural changes in the F8 gene. METHODS:Adjusted logistic regression analysis of the "My Life Our Future" database containing demographic, clinical, and F8 sequence data from >6000 mild, moderate, and severe HA participants. RESULTS:Black and Hispanic severe HA subjects had a higher inhibitor risk than non-Hispanic Whites (adjusted odds ratio = 1.65, 95% CI: 1.22-2.21 and adjusted odds ratio = 1.88, 95% CI: 1.43-2.48), confirming this racial/ethnic/medical disparity; however, F8 ns-SNPs were not associated with inhibitor development. There was no difference in inhibitor risk among severe HA subjects with an intron-22 inversion vs other large structural changes in the F8 gene. CONCLUSIONS:Nonpathogenic ns-SNPs in the F8 gene are not correlated with inhibitor risk. Inhibitor risk associated with intron-22 inversion mutations is similar to that of other large structural changes in F8 that preclude intact FVIII expression.

We report the first Human Immune System (HIS)-humanized mouse model (“DRAGA”: HLA-A2.HLA-DR4.Rag1KO.IL-2RγcKO.NOD) for COVID-19 research. This mouse is reconstituted with human cord blood-derived, HLA-matched hematopoietic stem cells. It engrafts human epi/endothelial cells expressing the human ACE2 receptor for SARS-CoV-2 and TMPRSS2 serine protease co-localized on lung epithelia. HIS-DRAGA mice sustained SARS-CoV-2 infection, showing deteriorated clinical condition, replicating virus in the lungs, and human-like lung immunopathology including T-cell infiltrates, microthrombi and pulmonary sequelae. Among T-cell infiltrates, lung-resident (CD103+) CD8+ T cells were sequestered in epithelial (CD326+) lung niches and secreted granzyme B and perforin, indicating cytotoxic potential. Infected mice also developed antibodies against the SARS-CoV-2 viral proteins. Hence, HIS-DRAGA mice showed unique advantages as a surrogate in vivo human model for studying SARS-CoV-2 immunopathology and for testing the safety and efficacy of candidate vaccines and therapeutics.