Kouides, Peter A.

Abstract Background Despite advances in the diagnosis and treatment of immune thrombotic thrombocytopenic purpura (iTTP), recent mortality estimates remain around 5–10%. Predicting iTTP mortality risk has been of interest, as it may help individualize treatment or potentially guide the use of more intensive or novel therapies based on disease severity. However, prior attempts at mortality prediction have yielded inconsistent results, and no individual variable has demonstrated independent or reliable predictive ability. In a previous analysis utilizing the USTMA iTTP registry, which included 419 patients from 15 TTP referral centers, we reported that mortality due to immune TTP was unpredictable (Blood. 2021;138[Suppl 1]:1047). Neither the French Thrombotic Microangiopathy (TMA) Reference Score (previously validated in the French TMA Registry), nor a previous logistic regression model attempt (developed by USTMA investigators in 2021) demonstrated sufficient accuracy in predicting iTTP mortality in the USTMA dataset (AUC = 0.63 and 0.69, respectively). We subsequently utilized gradient boosted machine, a machine learning approach capable of handling multiple continuous variables and the complex interactions between them in large datasets, and developed a novel prediction tool: the USTMA Mortality Index (Res Pract Thromb Haemost. 2024; 8(3):102388). It demonstrated good performance in predicting iTTP mortality (AUC = 0.77) in repeated 10-fold cross-validation. However, it has not yet undergone external validation. Objectives To externally validate the USTMA Mortality Index to predict mortality due to acute iTTP in a multicenter cohort. Methods We performed an external validation using an independent cohort of iTTP patients from 5 institutions: University of Utah, Case Western Reserve University, Rochester Regional Health, University of Illinois, and Mayo Clinic. Patients in the validation cohort were not part of the development cohort (the USTMA registry). We included patients with confirmed iTTP and defined acute iTTP mortality as death within 30 days of admission. USTMA Mortality Index variables were collected at initial presentation, which included (in order of highest to lowest relative influence): lactate dehydrogenase, serum creatinine, age, hemoglobin, platelet count, presence of stupor/coma, fever. The model's prediction accuracy was assessed using area under the receiver operating characteristic curve (AUC). We calculated sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) based on the previously defined cut-offs of 4.27% and 9.08% mortality risk in the original model, which categorized patients into standard risk, high risk, and very high risk of predicted mortality. Results The external validation cohort included 103 patients with confirmed iTTP and 11 deaths (10.7% mortality rate). The USTMA Mortality Index demonstrated poor performance with AUC of 0.69 (95% CI, 0.55–0.83) in the validation cohort. The wide confidence interval reflects substantial uncertainty in model performance, ranging from poor to excellent, and is likely due to the small number of deaths. At a risk threshold ≥4.27%:Sensitivity = 64%Specificity = 70%PPV = 20%NPV = 94% At a risk threshold ≥9.08%:Sensitivity = 18%Specificity = 87%PPV = 14%NPV = 90% Conclusion The USTMA Mortality Index demonstrated poor performance in the external validation cohort (AUC = 0.69, 95% CI, 0.55–0.83), contrasting with its previously favorable performance in repeated 10-fold cross-validation. This discrepancy likely reflects model overfitting, a known challenge in AI-based clinical modeling. Our study is limited by the small number of deaths, resulting in a wide confidence interval ranging from poor to excellent performance. Given that neither the French TMA Reference Score, nor our group's prior logistic regression model (2021), nor the USTMA Mortality Index (2024) could reliably predict mortality upon external validation in our cohorts, these findings collectively suggest that mortality in acute iTTP remains difficult to predict at this time, regardless of statistical methodology or current machine learning capabilities. Clinical decision-making, including the use of therapies such as caplacizumab, should not be guided solely by mortality risk predictions. Instead, efforts to reduce mortality and improve outcomes should prioritize individualized clinical assessment over model-based stratification at this time.

Introduction: Severe hemophilia A (HA) in females is incredibly rare particularly if complicated by a high-titer factor VIII (FVIII) inhibitor. We report, to the best of our knowledge, the first-of-its-kind use of emicizumab (emi) ante/post-partum, its effect on the newborn, and its excretion in breast milk. Baseline details: 29-year-old-female was diagnosed with severe HA at age 1 following prolonged bleeding from a venipuncture site. She had no family history of HA. One stage FVIII activity (OSA) was less than 1%. She was compound heterozygous for F8 type 1 and type 2 intron 22 inversions. At 21 months of age, she developed a high-titer inhibitor (peak: 35 Bethesda unit[BU]). She was not treated with immune tolerance induction and had remained on factor eight inhibitor bypassing activity (FEIBA) as prophylaxis until transferring to our center. She was transitioned to monthly emi prophylaxis and recombinant FVIIa (rFVIIa, NovoSeven) for breakthrough bleeding at age 26. She was medically advised against pregnancy due to unclear safety profile of emi in pregnancy and theoretical concerns for an increased risk of bleeding and thrombotic complications associated with the use of bypassing agents in the peripartum setting. Nevertheless, she desired pregnancy and continued on emi prophylaxis every 4 weeks during her pregnancy. Clinical course in pregnancy: She had an uncomplicated antepartum course and did not require rFVIIa for breakthrough bleeds. Blood emi levels and FVIII inhibitor levels were measured in each trimester of pregnancy (Table 1). Her labor was induced with oxytocin while on rFVIIa and tranexamic acid (TXA) support. She had a spontaneous, unassisted vaginal delivery immediately complicated by post-partum hemorrhage resulting in estimated blood loss of 1100cc. She did not require blood transfusion. She continued on 90 mcg/kg rFVIIa support every 2 hours, gradually prolonging the dosing interval by 2 hours every 24 hours (q2, q4, q6, etc.), and experienced no further in-hospital bleeding. She delivered a healthy female newborn. The infant developed cephalhematoma but transcranial ultrasound was negative for intracranial bleeding. Cord blood was collected at the time of delivery and sent for emi level, FVIII activity and FVIII inhibitor titer (Table 2). FVIII inhibitor assay with bovine reagent (CBU) was performed using chromogenic substrate assay (CSA) after pre-analytical heat-inactivation of patient plasma. The infant's CSA FVIII level was measured using a bovine chromogenic FVIII assay, and FVIII was also assayed using a one-stage APTT-based assay. Mother opted to breast-feed the infant. Emi level was measured in breast milk (Table 1). Conclusion: In this highly unusual case, we demonstrate that emi crossed the placenta and is excreted in breast milk. We also demonstrate that the maternal FVIII inhibitor did not cross the placenta into the newborn. Drawing conclusions on the safety of emi despite placental and breast milk transmission and transmissibility of inhibitor based on a single case would be premature. The conglomeration of several rarities in a single case renders our report unique and insightful and provides a baseline experience for future cases.

Abstract Introduction It is well established that von Willebrand factor (VWF) levels increase with age among healthy adults. Recently, there is emerging research demonstrating this may also occur in patients with von Willebrand disease (VWD), particularly type 1 VWD, and may be related to comorbidities. Despite increasing VWF levels, it remains unclear as to whether or not this alters bleeding phenotype. It is also unclear why this occurs most commonly in patients with type 1 VWD, but VWF mutation status may play a role. Older patients commonly undergo invasive procedures, and all VWD patients require periprocedural VWD-specific therapy to ensure appropriate hemostasis. If older type 1 VWD patients have experienced normalization of VWF levels, and no longer have an increased risk of bleeding, VWD-specific therapy may increase thrombosis risk, especially among patients with underlying cardiovascular disease or related risk factors, subject the patient to other adverse reactions such as hyponatremia, and is unnecessarily costly. For these reasons, investigation into the effect of age on VWF levels and bleeding risk in type 1 VWD patients is sorely needed. Methods This is an NHLBI-funded K23 multicenter, cross-sectional study to determine the effect of age on VWF levels and bleeding risk in patients with type 1 VWD, and to determine if pathogenic VWF mutations alter this effect.Individuals with a new or historical diagnosis of type 1 VWD (defined as clinical symptoms consistent with VWD and VWF antigen level or ristocetin cofactor activity <0.50 IU/mL) and age 18 or older are enrolled during routine clinic visits at participating Hemophilia Treatment Centers (HTCs). Following enrollment, pertinent medical history is obtained; the condensed MCMDM-1 VWD Bleeding Assessment Tool is administered, with bleeding history based on bleeding symptoms during the past 5 years; and blood samples are collected for the following: VWF antigen (VWF:Ag) level, VWF ristocetin cofactor activity, factor VIII activity, blood type, and VWF gene sequencing. We hypothesize age is associated with increased VWF:Ag levels and lower condensed MCMDM-1 VWD bleeding scores in patients with type 1 VWD, and this association is weaker among those with a pathogenic VWF mutation. In addition, we hypothesize multimorbidity partially explains the association between age and VWF:Ag levels, and VWF:Ag levels partially explain the association between age and condensed MCMDM-1 VWD bleeding scores in patients with type 1 VWD. A sample size of 250 participants provides 90% power to detect an effect size of Beta=±0.032 points per year of age, which is much smaller than the observed effect size, Beta=-0.080, from preliminary data. The primary analyses will be based on multivariable linear regression models with adjustment for blood type O, exogenous estrogen therapy, multimorbidity (defined as 2 or more of the core set of 20 chronic conditions, i.e., cancer, hypertension, stroke, etc., as selected by the United States Department of Health and Human Services), and medications (aspirin, nonsteroidal antiinflammatory drugs, and anticoagulants). In the regression models, two-sided t-tests will be used with an alpha=0.05. Results This multicenter, cross-sectional study consists of seven HTCs: Hemophilia Center of Western Pennsylvania, Children's Hospital of Pennsylvania, Mary M. Gooley Hemophilia Center, Ohio State University, Bleeding & Clotting Disorders Institute, Mayo Clinic, and University of California, San Diego. During the first year of the study, site initiation visits were conducted, regulatory approval obtained, and contracts executed. Delays in these activities occurred in large part due to the COVID-19 pandemic. As the first year of the study concludes, all sites are now active and enrolling participants. Thus far, 43 participants have been enrolled (Table 1). No barriers to enrollment have been encountered and very few patients have declined study participation. Discussion In conclusion, this ongoing multicenter, cross-section study seeks to determine the effect age has on VWF levels and bleeding risk in patients with type 1 VWD while exploring the role of VWF mutations and multimorbidity in this process. The results will be used to justify a longitudinal study, which is the ideal approach to research the effects of aging in this population. Figure 1 Figure 1. Disclosures Seaman: Sanofi: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; HEMA Biologics: Consultancy, Honoraria. Ragni: Bioverativ (Sanofi): Membership on an entity's Board of Directors or advisory committees; Spark Therapeutics: Membership on an entity's Board of Directors or advisory committees; Takeda Therapeutics: Membership on an entity's Board of Directors or advisory committees; Alnylam (Sanofi): Membership on an entity's Board of Directors or advisory committees; University of Pittsburgh: Research Funding; BioMarin Pharmaceutical: Membership on an entity's Board of Directors or advisory committees. Kraut: Uniqure: Consultancy. Pruthi: CSL Behring: Honoraria; Bayer Healthcare AG: Honoraria; Instrumentation Laboratory: Honoraria; Genentech: Honoraria; HEMA Biologics: Honoraria; Merck: Honoraria. Raffini: CSL Behring: Consultancy; HEMA Biologics: Consultancy; Genentech: Consultancy; Bayer: Consultancy; XaTek: Consultancy. Roberts: Takeda; Speakers Bureau: Novo Nordisk, Octapharma, Sanofi, Takeda.: Research Funding; Genentech, Novo Nordisk, Octapharma, Pfizer, Sanofi, Takeda, uniQure: Consultancy. von Drygalski: Genentech: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; uniQure: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sanofi: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Biomarin: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; CSL Behring: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pfizer: Research Funding; Novo Nordisk: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Hematherix, Inc: Membership on an entity's Board of Directors or advisory committees, Patents & Royalties: Super FVa.

Abstract Context. —Systemic mastocytosis is characterized by abnormal growth and accumulation of neoplastic mast cells in various organs. The clinical presentation is varied and may include skin rash, symptoms related to release of mast cell mediators, and/or organopathy from involvement of bone, liver, spleen, bowel, or bone marrow. Objective. —To concisely review pathogenesis, disease classification, clinical features, diagnosis, and treatment of mast cell disorders. Data Sources. —Pertinent literature emerging during the last 20 years in the field of mast cell disorders. Conclusions. —The cornerstone of diagnosis is careful bone marrow histologic examination with appropriate immunohistochemical studies. Ancillary tests such as mast cell immunophenotyping, cytogenetic/molecular studies, and serum tryptase levels assist in confirming the diagnosis. Patients with cutaneous disease or with low systemic mast cell burden are generally managed symptomatically. In the patients requiring mast cell cytoreductive therapy, treatment decisions are increasingly being guided by results of molecular studies. Most patients carry the kit D816V mutation and are predicted to be resistant to imatinib mesylate (Gleevec) therapy. In contrast, patients carrying the FIP1L1-PDGFRA mutation achieve complete responses with low-dose imatinib therapy. Other therapeutic options include use of interferon-α, chemotherapy (2-chlorodeoxyadenosine), or novel small molecule tyrosine kinase inhibitors currently in clinical trials.

Abstract Menorrhagia is a common clinical problem among reproductive age women and annually 5% of reproductive age women seek medical attention, usually with gynecologists and other primary care physicians, for this symptom. Since underlying bleeding disorders are common in women presenting with menorrhagia, and referral for comprehensive hemostatic testing of substantial numbers of women with otherwise unexplained menorrhagia is problematic from the public health and cost perspective, a short, easy-to-administer screening tool comprised of 8 questions for identifying women with menorrhagia for hemostatic evaluation was previously developed (Am J Ob Gyn2008;198:e1–163e8). In the present study, the validity of the screening tool was evaluated in a multi-site, prospectively recruited cohort of women with menorrhagia. 232 women with menorrhagia age 18 and older with a pictorial blood assessment chart (PBAC) score > 100 were recruited from 5 US centers as potential subjects for a prospective cross-over study for evaluation of intranasal DDAVP versus tranexamic acid. All subjects underwent comprehensive laboratory testing for bleeding disorders, including VWF, platelet aggregation/ATP release, and factor assays. Study participants were administered a questionnaire which included the 8 screening tool questions in 4 categories, including history of duration and severity of menorrhagia, anemia treatment, excessive bleeding with hemostatic challenges, and family diagnosis of bleeding disorder. A screening tool was considered positive if there was a positive response for any of the questions in the four categories. Sensitivity of the screening tool with 95% confidence interval was calculated for bleeding disorders and also separately for low VWF (ristocetin cofactor < 50%), and platelet function defects.217 women with menorrhagia including 78% white and 16% black women with complete data were evaluated. In this population, a positive screening tool had a sensitivity of 89% (95% CI, 83–93) for bleeding disorders, 89% for platelet function defects (95% CI, 82–94), and 73% for low VWF (95% CI, 39–94). The sensitivity for bleeding disorders was 87% (95% CI, 79–92) among white women and 94% (95% CI, 79–99) among black women. Adding a PBAC score > 185 increased the sensitivity of the screening tool for bleeding disorders to 95% (95% CI, 90–98). Using a multi-site US population of adult women with menorrhagia, this study confirms the benefit of a short screening tool to assist primary care physicians in the selection of women with menorrhagia to refer for comprehensive hemostatic testing and evaluation. population of adult women with menorrhagia, this study confirms the benefit of a short screening tool to assist primary care physicians in the selection of women with menorrhagia to refer for comprehensive hemostatic testing and evaluation.

Introduction: Menorrhagia is a common health problem affecting ∼5-10% of women. The optimal management of menorrhagia among women with abnormal laboratory hemostasis is uncertain. The goal of this study was to determine the effect of intranasal desmopressin (IN-DDAVP) vs. oral tranexamic acid (TA) on menstrual blood loss (MBL) and quality of life (QOL). Methods: In a cross-over study design, 117 consenting women 18–50 years of age with menorrhagia (defined as subjective report of heavy bleeding and a pictorial blood assessment chart [PBAC] score > 100) with a negative gynecological evaluation and abnormal laboratory hemostasis (62% platelet dysfunction, 15% von Willebrand disease, 23% other coagulation defect or combined) were randomly assigned to initial IN-DDAVP or TA therapy each for two menstrual cycles, followed by cross-over to the second study drug for an additional two cycles. MBL by PBAC was measured at baseline and after each menstrual cycle while QOL was assessed by four validated instruments: Health Related Quality of Life (HRQOL), SF-36®, Center for Epidemiologic Studies Depression Scale (CES-D) and the Ruta menorrhagia questionnaire. Results: There was a statistically significant decrease in the PBAC for both treatments. On average, the estimated decrease in the PBAC from baseline for IN-DDAVP was −66.0 (CI = (−89.5, −42.6)) and for TA, −107.8 (CI = (−131.5, −84.1)). The decrease in the PBAC score was larger for TA with a difference of 41.8 (p-value = 0.0002, CI = (20.4, 63.2)) between the two treatments. In the multivariable analysis, the test for treatment-cycle number interaction was not significant, suggesting no carry-over effect. The test for a treatment type effect was significant (p<0.0001) suggesting a greater reduction in PBAC score with TA compared to IN-DDAVP. Both IN-DDAVP and TA generally improved QOL as assessed by each of the four instruments. Over-all, the Ruta Menorrhagia Questionnaire and the Center for Epidemiologic Studies Depression Scale measurements showed the most statistically significant improvements. Conclusion: Both TA and IN-DDDAVP reduce MBL and improve QOL in females with menorrhagia and abnormal laboratory hemostasis.The significance of these findings are underscored by the fact that prior studies of menorrhagia treatment in these patients have not included validated QOL instruments. The marked improvement in MBL and QOL noted with TA and IN-DDAVP appears to justify hemostasis screening in women presenting with menorrhagia for whom no gynecological cause can be found.