Citations

Abstract Background Strongyloides stercoralis is an intestinal parasitic nematode with a 2% - 7% prevalence in the United States. Immunosuppression can predispose to disseminated infection, concurrent bacterial sepsis and significant morbidity and mortality. We sought to review positive Strongyloides serology (PSS) results across 3 academic medical centers. Methods Electronic medical records of patients with PSS were reviewed between 2012 and 2023. Extracted data included demographics, country of origin, travel history, testing indication, clinical presentation, treatment regimen and duration. Patients were classified into chronic infection (PSS without additional clinical manifestations), hyper infection syndrome (cutaneous, gastrointestinal tract, or lung involvement), and disseminated infection (evidence of involvement of distant sites beyond hyper infection such as the brain, liver, kidneys, or bloodstream). Results Overall PSS rate across the 3 sites was 5.5%. A total of 412 patients with PSS were identified with a mean age of 56.7 years (SD ±14.2); 272 (66%) were male. The primary indication for testing was transplant evaluation in 230 (56%), eosinophilia workup in 84 (20%), suspicion of active infection in 74 (18%), travel history in 27 (7%), and pre-immunosuppression screening in 27 (7%). 401 (97.3%) were categorized as chronic infection,10 (2%) as hyper infection, and one patient (0.2%) as disseminated infection. Treatment was administered to 366 (89.3%) patients: 226 (61.7%) received 2 doses of Ivermectin on consecutive days, 94 (25.7%) received a single dose, 26 (7.1%) received 2 doses repeated 2 weeks later, and 20 (5.5%) received alternative regimens. The patient with disseminated infection received 2 weeks of Ivermectin followed by monthly dosing. Conclusion Majority of the patients with PSS were asymptomatic, and treatment regimens were not uniform. Screening should be considered for patients currently receiving or initiating long-term immunosuppression that can potentiate Strongyloides dissemination. Developing a targeted testing algorithm based on epidemiologic factors, clinical suspicion, laboratory parameters and nature of immunosuppression can help identify at-risk patients who can receive pre-emptive therapy if infected. Disclosures All Authors: No reported disclosures

Abstract JAK2 unmutated/wild-type erythrocytosis is a prevalent condition encompassing a wide spectrum of hereditary and acquired entities. It is conventionally defined by the same hemoglobin/hematocrit thresholds as for polycythemia vera. Incidence has been reported to be between 0.13% and 4.1%. The most clinically relevant step in the workup of erythrocytosis is the exclusion of polycythemia vera through JAK2 mutation screening. Consideration of relative polycythemia, normal outliers, and the influence of erythropoietic drugs and comorbidities is also imperative. Distinguishing long-standing from newly acquired erythrocytosis further streamlines the diagnostic process. Hereditary erythrocytosis (HE) is lifelong and typically associated with a positive family history. Subnormal serum erythropoietin (EPO) suggests an EPO receptor mutation. Otherwise, oxygen tension at 50% hemoglobin saturation (p50) discerns between high oxygen-affinity hemoglobin variants, 3-bisphosphoglycerate deficiency, methemoglobinemia, and PIEZO1 mutations (low p50) and germline oxygen-sensing pathway/other rare mutations (normal p50). Acquired erythrocytosis results from hypoxia-driven factors (eg, cardiopulmonary, altitude, renal artery stenosis) and other mechanisms of EPO overproduction (eg, EPO-secreting tumors) or hypersensitivity, as well as EPO-independent mechanisms. Drugs (eg, sodium glucose co-transporter-2 inhibitors, testosterone) are also common causes. Idiopathic erythrocytosis is a diagnosis of exclusion, increasingly attributed to underlying genetic mutations/polymorphisms. There are currently no evidence-based treatment guidelines. Low-dose aspirin and/or phlebotomy (with frequency determined by symptom relief) might be considered on an individualized basis in the presence of hyperviscosity symptoms, cardiovascular comorbidities, and/or a history of thrombosis. Aggressive control of cardiovascular risk factors is recommended in all. A graphic abstract representation is provided in Figure 1.

Abstract Introduction: CSF3R mutations (CSF3RMUT), most commonly T618I, represent the defining genomic alteration in chronic neutrophilic leukemia (CNL), present in ~80% of cases. Despite emerging real-world data, information on treatment outcomes and prognostic factors remains limited due to rarity of the disease. In this two-center retrospective study, we examined clinical and molecular predictors of treatment response, overall survival (OS), and blast transformation (BT) and outcome following allogeneic stem cell transplant (ASCT). Methods: The study was approved by the institutional review boards of the Mayo Clinic (USA) and the University of Montreal (Canada). Electronic medical records were reviewed to identify patients with CSF3R mutated CNL at both institutions and extract relevant data. Statistical analyses were conducted using JMP Pro 17.0.0 software (SAS Institute, Cary, NC, USA). Results: Forty-four patients (68% male, median age 68 years [range: 26-93]) were included. At diagnosis, 20 (56%) were asymptomatic, 13 (36%) presented with constitutional/non-specific symptoms, and 20 (50%) had antecedent leukocytosis at a median of 13 months(mo) prior. Splenomegaly (palpable or radiological) was observed in 28 (67%) patients, hepatomegaly in 7 (17%) and lymphadenopathy in 4 (9.8%). Median white blood cell count (WBC) was 52×10⁹/L (range: 17-390). CSF3RMUT/variants included 39 (89%) with T618I (7 of the 39 had additional CSF3RMUT), 2 (5%) with M696T, and 1 (2%) each for I598I, Q739* and T640N. Frequent co-mutations included ASXL1 in 25 (63%) patients, SETBP1 in 14 (36%), and SRSF2 in 8 (31%), with overlapping occurrence; 10 (38%) patients had ≥2 of these 3 mutations. Ten patients (median WBC 29 x10⁹/L [range: 19–58]), were initially observed without treatment for a median of 8.6 mo; 2 remained on observation alone at 46 and 77 mo. Hydroxyurea (HU) alone or in combinations excluding ruxolitinib (Ruxo) was the most common first-line treatment (68%). Second-line therapies included Ruxo (39%), HU (25%), and hypomethylating agents (14%). WBC response (≥50% reduction from baseline) was 78% with HU vs. 60% with Ruxo (p=0.2). WBC response to HU was lower with abnormal karyotype (40% vs. 94%; p=0.02). WBC response to Ruxo was lower with SETBP1MUT (0% vs. 72%; p=0.05) and with male sex (40% vs. 100%; p=0.04). Seven patients underwent ASCT, including 2 after BT; four (57%) of the 7 remain alive, including 2 without evidence of disease (both 45 mo post-ASCT; one harbored ASXL1MUT) and the other 2 with active disease (both harbored ASXL1MUT). Three patients died from veno-occlusive disease (Day+34), CNS relapse with AML (at 105 mo post-ASCT), or unrelated causes (at 44 mo post-ASCT). Median OS was longer in transplanted patients (115 vs 23 mo; p=0.03). At a median follow-up of 44 mo for living patients, disease transformation occurred in 10 patients, including 7 with BT (6 with T618I, 1 T640N) and 3 with chronic myelomonocytic leukemia (2 M696T, 1 T618I). BT rate at 2, 3, and 5 years was 15%, 31%, and 43%, respectively. Univariate analysis (UVA) identified male gender (p<0.01), >5% immature WBCs (p=0.02), platelets <160×10⁹/L (p=0.04), higher WBC (p=0.02), and ASXL1 or SETBP1 mutation (p<0.01) as risk factors for BT. On multivariable analysis (MVA), only the latter remained significant. Median OS was 26 mo (95% CI: 21-43) for the entire cohort; 24 mo for patients with T618I CSF3RMUT vs 53 mo with other CSF3RMUT, p=0.1. In UVA, age >60 years (HR 5.0, p=0.03), platelets <160×10⁹/L (HR 3.4, p=0.006), WBC >50×10⁹/L (HR 2.6, p=0.02), and ASXL1 or SETBP1 mutations (HR 4.2, p=0.01) were associated with shorter OS. In MVA, age >60 (HR 6, p=0.03), WBC >50×10⁹/L (HR 12, p<0.01), and the presence of ASXL1MUT or SETBP1MUT (HR 9.5, p=0.01) remained significant. Based on the HRs on MVA, one adverse point was allocated for age >60 years, and two adverse points each for WBC >50×10⁹/L and presence of ASXL1 or SETBP1 mutations. Patients were accordingly stratified into low (0-2 points), intermediate (3) and high (4-5) risk groups with corresponding median OS of “not reached”, 29 mo, and 16 mo (p<0.01). Causes of death included disease progression (82%), infection/bleeding (9%), and ASCT complications (9%). Conclusion: The current study highlights the prognostic relevance of “SETBP1 or ASXL1” mutation for both overall survival and risk of blast transformation. The study also signifies variable natural history and potential benefit from ASCT.

Abstract Introduction: Lutetium-177 DOTATATE peptide receptor radionuclide therapy (PRRT) is an effective treatment for gastroenteropancreatic neuroendocrine tumors (GEP-NETs). While generally well tolerated, PRRT can result in hematologic toxicity ranging from mild cytopenias to therapy-related myeloid neoplasms (t-MNs). Understanding the incidence, severity, and clinical consequences of hematologic toxicity is essential for optimizing treatment decisions and establishing effective monitoring strategies. This study aimed to characterize hematologic toxicity patterns, severity, and recovery profiles in GEP-NET patients treated with Lutetium-177 DOTATATE PRRT and to determine the frequency of cytopenia-related treatment discontinuation. Methods: We conducted a retrospective analysis of 160 consecutive GEP-NET patients who underwent PRRT. Hematologic parameters (hemoglobin, white blood cell count, absolute neutrophil count, platelet count, and lymphocyte count) were assessed at baseline, mid-treatment (post-cycle 2), and post-treatment (post-cycle 4). Cytopenias were graded using Common Terminology Criteria for Adverse Events version 4.03 and categorized as never (grade <2 throughout), transient (grade ≥2 mid-treatment, resolving post-treatment), persistent (grade ≥2 at both timepoints), or late-onset (grade <2 mid-treatment, grade ≥2 post-treatment). Treatment completion rates and discontinuation reasons were documented. Results: Overall, 73% of patients (117/160) completed all planned PRRT cycles. Among the 43 patients who discontinued treatment early, only 4 (2.5% of total cohort) discontinued specifically due to cytopenia, while the remainder discontinued for other reasons. Post-treatment grade ≥2 cytopenias were uncommon: lymphocytes (4.4%), hemoglobin (2.5%), neutrophils (1.9%), white blood cells (1.3%), and platelets (1.3%). The majority of patients (≥85%) never experienced grade ≥2 cytopenia throughout treatment. When cytopenias occurred, they were predominantly transient (8-10% of patients) with complete recovery by treatment completion. Persistent cytopenias were rare (<5% across all cell lines), while late-onset cytopenia occurred most frequently with neutrophils (14%). Conclusion: Lutetium-177 DOTATATE PRRT demonstrates an excellent hematologic safety profile in GEP-NET patients. Severe cytopenias are uncommon, predominantly transient, and rarely necessitate treatment discontinuation. These findings support the continued use of PRRT in appropriate candidates, with cytopenia-related discontinuation occurring in fewer than 3% of cases. Long-term follow-up remains essential to monitor delayed hematologic effects, including t-MNs. Future research should evaluate baseline predictors such as prior chemotherapy, renal function, and marrow reserve to identify patients at higher risk who may benefit from closer hematologic surveillance.

ABSTRACT Background Critically ill patients may be overexposed to valproate because altered protein binding leads to a disproportionate free valproate fraction. The Fraser equation was derived and internally validated to estimate critically ill patients' free valproate concentrations, but it requires external validation. Methods Adult intensive care unit (ICU) patients at two academic centers with concurrently measured free and total valproate concentrations were included. Free valproate concentrations were estimated using the Fraser equation which includes total valproate, albumin and BUN concentration, and whether the patient received propofol or aspirin. The primary outcome was Fraser equation performance, assessed using Bland–Altman methods. Comparative performance against estimates from the Doré equation (an alternative predictive equation), therapeutic concordance using a target free valproate range of 5–15 mg/L, and equation improvements were explored. Results Overall, 315 patients and 556 free‐total valproate concentration pairs were included. The mean (±SD) age was 58 (±17) years and 90 (29%) patients were on valproate prior to hospital admission. The Fraser equation estimated free valproate concentrations were correlated with measured concentrations ( r = 0.728) with a negative bias (mean bias −2.77 mg/L, 95% LOA –18.9, 13.4). The Fraser equation increasingly underestimated measured concentrations as measured concentrations increased. 71% of Fraser equation estimates were therapeutically concordant (e.g., estimate and measured both within reference range) compared to 61.9% of Doré estimates ( p = 0.001). Fraser equation modifications led to minor performance improvements but did not overcome worsening underestimation with higher measured free valproate concentrations. Conclusion The Fraser equation was moderately accurate and corresponded with an appropriate interpretation for 71% of free valproate concentrations. Worse underestimation with higher measured free valproate concentrations suggests direct measurement of free valproate concentrations is warranted. While the Fraser equation could complement therapeutic decision making at centers where direct free valproate measurements are unavailable or slow to return, its accuracy is currently insufficient to replace direct measurement.

Abstract This brief report details the initial findings from a Phase 1b/2 trial of TN-201, an adeno-associated virus serotype 9 (AAV9) gene therapy for MYBPC3-associated hypertrophic cardiomyopathy (HCM), a condition with significant morbidity, increased risk of mortality, and no approved therapy for the majority of patients. TN-201 was well tolerated, and changes to the management of potential immune responses resulted in a shorter period of immunosuppression. These results show consistent transduction and expression of TN-201 in cardiomyocytes, corresponding with increases in MyBP-C levels, reductions or stabilization of cardiac biomarkers, and reductions in key measures of left ventricular (LV) hypertrophy.

ABSTRACT Disease Overview JAK2 unmutated erythrocytosis encompasses a heterogeneous spectrum of hereditary and acquired entities. Diagnosis The foremost step is excluding polycythemia vera (PV) with JAK2 mutation screening (exons 12–15). Apparent polycythemia such as physiological outliers or relative polycythemia secondary to volume contraction should be considered. A historical overview of hematocrit (Hct) and hemoglobin (Hgb) levels helps distinguish longstanding from acquired erythrocytosis. Serum erythropoietin (Epo) levels are variably informative. Hereditary Erythrocytosis Hereditary erythrocytosis should be considered in longstanding erythrocytosis with a positive family history; causes include EPOR mutations (subnormal Epo), high oxygen affinity hemoglobin variants, PIEZO1 mutations, 2,3‐bisphosphoglycerate deficiency, methemoglobinemia, and germline oxygen sensing pathway mutations ( HIF2A ‐ PHD2 ‐ VHL ). Acquired Erythrocytosis Acquired erythrocytosis results from central (cardiopulmonary disease) or peripheral (renal artery stenosis) hypoxia, Epo‐producing tumors (renal cell carcinoma) or drugs (testosterone, sodium glucose co‐transporter‐2 inhibitors (SGLT2‐i), erythropoiesis stimulating agents). Idiopathic Erythrocytosis Idiopathic erythrocytosis is an ill‐defined terminology that presumes the existence of an increased Hgb/Hct level without an identifiable etiology. Management Cytoreductive therapy should be avoided. Phlebotomy should be considered for symptom control. Cardiovascular risk optimization and low‐dose aspirin are advised, while the role of HIF2A inhibitors remains unclear. Recent Advances EPO mutations which produce hyperactive, hepatic‐like Epo were identified. In cases with negative workup but high clinical suspicion, an expanded next generation sequencing panel for hereditary erythrocytosis is recommended. Among drugs, SGLT2‐i‐associated erythrocytosis is increasingly recognized. Future Directions Advances in molecular hematology are expected to improve the characterization of “idiopathic erythrocytosis”. Results from prospective studies are needed to elucidate the underlying pathology and guide management.

Stereotactic radiosurgery was associated with a higher obliteration rate compared with embolization in patients with eloquent brain arteriovenous malformations, whereas there was no evidence of a difference in functional outcomes or complications after adjustment.