Pruthi, Rajiv K.

ABSTRACT Background Platelet factor 4‐polyanion enzyme‐linked immunosorbent assays (ELISAs) are considered highly sensitive for diagnosing heparin‐induced thrombocytopenia (HIT), such that current practice guidelines recommend use of ELISA‐negative results to exclude HIT. Once HIT is ruled out, alternative, non‐heparin‐based anticoagulant treatments are ceased, and heparin reintroduction frequently occurs. Methods Antigen‐based and PF4‐dependent functional testing were used to study PF4/polyvinylsulfonate ELISA‐negative platelet‐activating antibodies in HIT‐suspected patients. Results Three patients with clinical presentations consistent with HIT tested negative in an ELISA using PF4‐polyvinylsulfonate (PF4/PVS), an antigenic target very commonly used for HIT antibody screening. All three patients demonstrated PF4‐dependent platelet activation in functional testing that was sensitive to blockade of platelet FcγRIIa receptors and inhibited by high concentrations of heparin, consistent with pathogenic HIT antibodies. Functional testing‐based screening of 500 ELISA‐negative patients identified three additional patients whose sera activated platelets in a PF4‐ and FcγRIIa‐dependent manner and had clinical histories consistent with HIT. Five of the six ELISA‐negative HIT patients were re‐exposed to heparin, which precipitated a decrease in platelet counts in all re‐exposed patients, and one patient developed a new thrombus. Conclusions Recognition of ELISA‐negative HIT is critical to avoid harm due to the cessation of alternative anticoagulation therapy and re‐exposure of these patients to heparin.

Abstract Background Interpretation of multi-analyte laboratory profiles, such as lupus anticoagulant (LAC) testing, requires integration of numerous test results and clinical information. However, this process is time-consuming, requires domain knowledge, and has limited scalability. Given that rule-based systems are rigid and difficult to maintain and large language models pose risks of “hallucinations,” we developed and evaluated a novel retrieval-based approach to automate LAC profile interpretation to improve efficiency while maintaining fidelity and reliability for clinical use. Methods Our method processes laboratory values through ensemble random forest (RF) models to retrieve the most similar expert interpretation from a curated database of 347 previously interpreted LAC profiles. The system's performance was assessed through technical accuracy metrics, a work flow efficiency timing study, and expert review of interpretation accuracy for held-out cases. Results Technical validation demonstrated high accuracy in retrieving correct interpretative elements (median: 93% accuracy, interquartile range [IQR]: 67% to 100%). Retrieval accuracy was highly correlated with the prevalence of a given element (ρ = 0.8307). In a timing study of 93 consecutive LAC profiles, ensemble-assisted interpretation achieved a median time of 22 s per report (IQR: 16 s to 31 s), representing a 78.6% total reduction compared to manual interpretation (median: 118 s, IQR: 96 s to 172 s; t = 18.61, P < 0.001). Furthermore, 92.5% of AI-assisted interpretations were completed within 60 s, exceeding the target of 85%. Expert review confirmed 100% concordance for LAC presence/absence. Conclusions The proposed approach significantly improves efficiency of complex laboratory interpretation for LAC profiles, while maintaining consistency and high fidelity. Future studies will explore the method’s inherent extensibility to the interpretation of other multi-analyte laboratory profiles.

Introduction: Calibrated automated thrombogram assay parameters have been shown to assess hypercoagulation state and, therefore, may independently predict posttrauma, symptomatic venous thromboembolism (VTE). Yet, calibrated automated thrombogram lacks high throughput and standardization, limiting diagnostic potential. This study analyzed thrombin generation (TG) profiles in trauma patients using a high-throughput assay, processing up to 10 samples at once, providing batch testing capabilities. We hypothesized that trauma patients who developed VTE would show distinct TG profiles compared with those who did not. Methods: Trauma patients presenting to a Level I Trauma Center had samples collected within 12 hours postinjury prospectively. Follow-up was conducted to 90 days, time to symptomatic VTE diagnosis or death, confirmed via autopsy or imaging. TG profiles were measured from the ST Genesia assay. Data were presented as median (interquartile ranges) or n (%), with the Wilcoxon rank-sum or chi-squared test. Associations between TG parameters and clinical risk factors were assessed using Spearman correlation analysis or the Wilcoxon rank-sum test. Results: Two hundred and fifty-four trauma patients were analyzed [48.5 years (31.0, 62.0), 72.0% male]: 64 patients with VTE (25.2%) to 190 with non-VTE. VTE pts had a median time to VTE of 8 days, with 29 developing deep venous thrombosis, 24 with pulmonary embolism, and 11 with deep venous thrombosis/pulmonary embolism. No significant differences were found in age, sex, or body mass index; significantly more VTE patients underwent surgery and blood transfusions within 24 hours. TG profiles demonstrated accelerated TG in patients who developed VTE compared with non-VTE, with significant differences in peak height ( P = 0.001), time to peak ( P = 0.021), endogenous thrombin potential ( P < 0.001), and velocity index ( P = 0.001). Conclusion: TG profiles using ST Genesia can differentiate trauma patients at high risk of developing VTE. The platform suits clinical labs needing high throughput by providing batch testing capabilities. Study type: Prospective study with less than large effect and no negative criteria. Level of evidence: II.

Abstract Background Congenital hemophilias affect about 30,000 US individuals (0.01% of the population) and atrial fibrillation (AF) about 10.5 million US individuals (4.5% of the population). Stroke prevention in this population is limited to expert opinion with formal guideline development hindered by a lack of clinical trials. Herein, we correlate outcomes of major bleeding and ischemic stroke with CV risk factors and antithrombotic management in our patient cohort. Methods This is a retrospective review (minimal risk study) of patients with hemophilia A, B, or C and concomitant AF diagnosed between 2000 and 2025. Patients were identified through a Mayo Clinic Rochester database using key terms. All cases were manually reviewed in the electronic medical record for appropriateness. Major bleeding was defined per International Society on Thrombosis and Haemostasis (ISTH) criteria. Stroke and bleeding risk were based on CHA₂DS₂-VASc and HAS-BLED scores. Analyses were performed using BlueSky Statistics software, with chi-square tests for categorical variables and Mann-Whitney U tests for continuous variables. Results A total of 21 patients were identified. Of these, 18 (86%) were male. Common comorbidities included type 2 diabetes (T2DM) in 14 (67%), hyperlipidemia in 18 (86%), hypertension in 18 (86%), and coronary artery disease in 12 (57%). Fifteen (71%) were never smokers. One patient (5%) had HIV on antiretroviral therapy, and five (24%) had a history of localized, resected cancer. Congenital hemophilia A was present in 12 patients (57%), hemophilia B in 5 (24%), and hemophilia C in 5 (24%). The median age at hemophilia diagnosis was 55.3 years. Hemophilia severity was mild in 17 (81%) and moderate in 4 (19%). Median factor level was 33% (SD=12.77%). Most were diagnosed with hemophilia from accumulation of minor bleeding events and family history. Six (29%) had major bleeds prior to AF diagnosis. The median age at AF diagnosis was 65.6 years. Paroxysmal AF was the most common subtype (11 patients; 52%), followed by permanent (5; 24%) and persistent (5; 24%). Median CHA₂DS₂-VASc and HAS-BLED scores at AF diagnosis were 2 and 1, respectively. At AF diagnosis, 2 patients (10%) were already on antithrombotic therapy (aspirin 81 mg [ASA]), both for recent transcatheter aortic valve replacement (TAVR). For AF-related stroke prevention, 5 patients (24%) were started on ASA and 5 others (24%) were started on apixaban. Cardioversion was performed in 5 patients (24%) and ablation in 2 (10%)). Five (24%) underwent procedural interventions (3 Watchman devices, 2 Maze procedures). Three patients (14%) had at least one major bleed following AF diagnosis. Bleed locations included traumatic intracranial, severe epistaxis, and spontaneous intracranial (one each). At the time of bleed, one patient was on ASA and two were on no antithrombotic or anticoagulation. One patient (5%) had a second major bleed – a muscle hematoma. He was not on antithrombotic or anticoagulation at the time. Two bleeds were fatal. Patient 1 was an 83-year-old male with moderate hemophilia A, a history of major GI bleed prior to AF diagnosis, a CHA₂DS₂-VASc score of 7 on ASA (taken for 11.5 years), and a HAS-BLED score of 3 who died of complications from severe epistaxis.Patient 2 was a 56-year-old male with moderate hemophilia B, a CHA₂DS₂-VASc score of 1, and a HAS-BLED score of 1 that died from a spontaneous intracranial bleed. One patient experienced an ischemic stroke: a 71 year old male with moderate Hemophilia A, a CHA₂DS₂-VASc score of 7, and a HAS-BLED score of 5 who was anticoagulated on apixaban. Conclusion: Despite the relatively low use of anticoagulation and antithrombotic, nearly 15% of this cohort experienced major bleeding after AF diagnosis, including two fatal events. Ischemic stroke was rare but occurred in a high-risk patient that was anticoagulated with apixaban. These findings demonstrate limitations of existing risk-stratification tools in this unique population, and support the need for larger studies and evidence based guidelines for patients with bleeding disorders and AF.

Abstract Introduction: Monoclonal gammopathy of thrombotic significance (MGTS) is a recently recognized thrombophilia where monoclonal platelet factor 4 (PF4)-specific IgG antibodies initiate a chronic prothrombotic state characterized by recurrent and potentially life-threatening thrombosis. Studies from large data sets demonstrate that patients with monoclonal gammopathy of undetermined significance (MGUS) have a heightened risk of experiencing thromboembolic events without a precise explanatory mechanism. The prevalence of MGTS in MGUS-related thrombosis is unknown; however, the recent identification of MGTS antibodies as a cause of thrombosis suggests a potentially causative mechanism. Emerging evidence indicates that detecting pathogenic MGTS antibodies presents diagnostic challenges due to the insensitivity of FDA-approved diagnostic assays adopted from HIT (HIT ELISAs) and gold-standard functional tests that use heparin-treated platelets, such as the serotonin release assay (SRA). Only PF4-enhanced functional assays, including the PF4-dependent P-selectin expression assay (PEA) and PF4-SRA, have proven sensitive for detecting MGTS antibodies. In this study, the PEA was utilized to better define the incidence of pathogenic anti-PF4 antibodies among a cohort of MGUS patients with a history of thrombosis. Methods: A search of the Mayo Clinic Dysproteinemia Bank was conducted to identify two cohorts of IgG MGUS patients, one with venous thromboembolism-associated diagnosis code(s) and the other without. A diagnosis of multiple myeloma was exclusionary. Each serum sample was assessed using the PEA. Mayo Clinic's Institutional Review Board approved the research study. Results: Among the 134 patients studied in the thrombosis cohort, 17 (13%) stimulated platelet activation in the PEA (positive cut-off ≥19%), some weakly. Of these, four patients (Patients 1-4) were confirmed to have PF4-dependent platelet-activating antibodies inhibitable with high concentrations of heparin and sensitive to blockade of the IgG receptor on platelets, FcGRIIa. The thrombotic complications experienced included recurrent deep venous thrombosis (DVT) over several years (Patient 1), a single DVT (Patient 2), a thrombotic cerebrovascular accident (CVA) (Patient 3), and a series of thrombotic events, including DVTs, left atrial thrombosis, pulmonary embolism, and acute limb ischemia (Patient 4). Notably, longitudinal samples spanning twelve years (Patient 1), six years (Patient 2), three years (Patient 3), and on a single sample date (Patient 4) were confirmed positive by PEA. The prolonged persistence of platelet-activating anti-PF4 antibodies in Patients 1-3 supported a diagnosis of MGTS in these patients. Strikingly, all four patients tested negative in two FDA-approved HIT ELISAs (Immucor PF4 IgG and Zymutest HIA IgG). SRA was negative for Patients 1 and 2, weakly positive for Patient 3 (33%), and positive for Patient 4 (72%). Of the 166 patients in the MGUS minus thrombosis cohort, one patient demonstrated a non-heparin induced HIT-like antibody that was HIT ELISA (Optical Density &gt;1.0) and PEA-positive, and inhibitable using high concentrations of heparin and FcGRIIa blockade. No follow-up samples were available to assess antibody longevity. The patient had no history of thrombosis, and testing demonstrated that the anti-PF4 antibody was not synonymous with the MGUS antibody.Conclusions: Among a cohort of 134 MGUS patients with thrombosis, the prevalence of MGTS was found to be 2.2% (3 patients with persistent platelet-activating anti-PF4 antibodies). The identification of anti-PF4 antibodies among MGUS patients provides a mechanism contributing to the increased thrombotic risk associated with monoclonal gammopathies. Antibody negativity in HIT ELISA and variable positivity in the SRA highlight the nonclassical serology associated with anti-PF4 antibodies in MGTS and support performing PF4-enhanced functional testing. In addition, some patients appear to produce coincidental (non-monoclonal) platelet-activating anti-PF4 antibodies without evidence of thrombosis, although the longevity of such antibodies could not be examined in the one patient where it was identified. These findings highlight the need for larger, prospective MGUS studies to validate these observations, further define the interplay between monoclonal gammopathies and thrombotic risk, and to better understand the long-term outcomes of patients with MGTS.

Abstract Gentically driven classical hematological disorders have variable prevelance in the general population, sickle cell disease (SCD) being the most common at 30 per 100,000 people, hemophilia (hem) 12 per 100,000 people for hemophilia A, 4 per 100,000 people for hemophilia B, and thalassemia (thal) at 18 per 100,000 people, with regional and racial-ethnic variation across US. There has been a dramatic change in the therapeutic landscape for these diseases in the past decade. Several new drugs and biological therapies including gene therapies have been approved for each of these disorders. Clinicians utilize different information sources to assimilate this rapid influx of knowledge into their practice; in the era of social media, the readership is not limited to original publications. As research visibility influences clinical adoption and patient awareness, it is vital to understand the modalities of engagement of gene therapy studies by clinicians and patients. An altmetric score is a simple and effective way of understanding engagement with research across platforms. It. measures digital attention received by research output, allowing us to gauge the social impact of an article. We sought to compare the impact and scientific dissemination of publications of gene therapy trials in these 3 diseases by capturing the number of traditional citations and Altmetric assessment score. Methods: A PubMed search was conducted for gene therapy trials in SCD, Hem and Thal between 2015 to 2025 and citations were captured using metrics from Google Scholar. The Altmetric assessment score for each article was determined using www.altmetric.com which includes any mention by news outlets, blogs, Twitter (X), Facebook, and Mendeley reader counts. Descriptive statistics are reported for the number of citations as well as the Altmetric assessment score in each of the disease categories. Median and range were reported due to the skewed distribution of the data. Comparison across groups for significance was done using the Kruskal-Wallis test. Results: The number of qualifying studies for SCD (n=7) were lower than hem (n=21) and thal (n=12). Median PubMed citations were highest for SCD (147, range 4-436), followed by hem (26, range 0-828) and thal (42, range 0-801), though the difference was not statistically significant (p=0.4) Altmetric scores demonstrated differences that approached statistical significance with p=0.08: SCD had the highest median (422, range 4-770), driven by exceptional Twitter engagement, while hem and thal medians were 20 (range 0-2038) and 49 (range 0-825) respectively. Twitter/X was the leading social platforms for all diseases. Scholarly interest measured by Mendeley readers was also highest for SCD (median 195, range 11-542), with thal and hem medians at 50 (range 0-773) and 64 (range 8-646) respectively. Conclusion: We observed substantial variability in both academic and social media dissemination of practice-changing SCD, Hem and thal gene therapy studies, though not statistically significant likely due to the limited number of studies overall. Higher citation count and Altmetric score in SCD studies may reflect recent robust dissemination efforts by ASH and patient advocacy groups. Intentional promotion across academic and media platforms increases awareness, helping with early dissemination of updated information that could have significant impact on patient outcomes.

Abstract Introduction A 2017 survey by the American Society of Hematology found a widespread perceived shortage of classical hematologists in the US, which was compounded by a low trainee interest in the field (&lt;5%) (Masselink LE, Blood Adv 2019). Recently, we reported that among hematologist/oncologists at the 64 National Cancer Institute (NCI)-designated cancer centers with clinical programs, only ~5% identify as classical hematologists, despite 15% of them including classic hematology (CH) patients in their practice (Go LT, Blood Adv, in press). However, there remains limited data on CH consult volumes at NCI-designated cancer centers (West CV, JCO Oncol Pract 2023). This study aimed to evaluate the volume and nature of CH outpatient consults at the Mayo Clinic Comprehensive Cancer Center (MCCC). Methods We reviewed electronic medical records to identify all completed outpatient consults in CH, malignant hematology (MH), and solid tumor oncology at MCCC in Rochester, Minnesota from January 1 to December 31, 2024. Consults were defined as either external or internal referrals for new patients seen in CH outpatient clinic. CH consults were further categorized by referral reasons and the type of physician (CH, MH, or fellow) performing the consultations. CH physicians were defined as those whose clinical practice primarily focuses on non-malignant hematologic conditions; one advanced practice provider (APP) was included in this group. Inpatient consults, electronic consults, and return visits were excluded. Results In 2024, a total of 17,153 outpatient consults were completed. Of these, 13.4% were CH, 30.5% were MH and 56.1% were solid tumor oncology. Among CH consults, the most common referral reasons were abnormal blood counts (68.3%), bleeding disorders (10.6%), thrombosis (11.8%), and other hematologic diagnoses (9.3%). Within abnormal blood counts, the leading indications were anemia (50.7%), thrombocytopenia (15.3%), leukopenia (11.0%), leukocytosis (9.1%), and pancytopenia (7.0%). Among bleeding disorders, the top reasons included suspected bleeding diathesis (49.4%), von Willebrand disease (24.5%), Hemophilia A (4.1%), Factor VII deficiency (3.7%), and platelet qualitative defect (3.4%). Thrombosis-related consults were most often for pulmonary embolism or deep vein thrombosis (43.2%), antiphospholipid syndrome (17.7%), thrombophilia (16.2%), portal vein thrombosis (4.1%), and splenic infarct (2.6%). The top ten referrals for a specific hematologic diagnosis were iron deficiency anemia (29.2%), pulmonary embolism or DVT (13.5%), immune thrombocytopenic purpura (10.3%), von Willebrand disease (6.9%), hemoglobinopathy (5.5%), antiphospholipid syndrome (5.5%), thrombophilia (5.1%), anemia of chronic kidney disease (2.4%), aplastic anemia (1.5%), and hereditary spherocytosis (1.4%). Of the 114 physicians at MCCC during the study period, 55 (48.2%) were medical oncologists, 54 (47.4%) primarily practiced MH, and only 5 (4.4%) were dedicated CH physicians. Despite comprising only 4.4% of the hematology/oncology workforce, CH physicians or fellows completed the majority (86.1%) of CH consults; MH physicians completed 13.8%. Conclusion CH consults represent a substantial portion of outpatient hematology referrals at MCCC, primarily for diagnostic evaluation of cytopenias or thrombotic/bleeding symptoms. However, a striking mismatch exists between CH physician representation (4.4%) and CH consult volume (13.4%). This imbalance has implications for quality, timeliness, and continuity of care for patients with non-malignant hematologic conditions. Our findings underscore the urgent need to expand recruitment and career development pathways in CH to address a huge clinical demand.