Citations

Objectives: To date, there are no specific guidelines on antithrombotic therapy (ATT) management, which includes both anticoagulation and antiplatelet medications, for open tracheostomy. The objective of this study was to evaluate whether the use of perioperative antithrombotic medication during open tracheostomy influences the incidence of perioperative or postoperative complications. Methods: A retrospective review was conducted of all patients who underwent open tracheostomies at a tertiary care medical center from January 2015 to December 2019. Charts were reviewed for demographics, comorbidities, indication for tracheostomy, ATT use, operative details, and complications. Results: A total of 217 tracheostomies were evaluated for this study, of which 148 (68.2%) were not on ATT and 69 (31.8%) were on ATT during surgery. No significant difference was observed based on ATT status in perioperative bleeding ( P = .983), postoperative bleeding ( P = .24), or median days to decannulation ( P = .5986). ATT patients were 2.67 times more likely to experience 30-day mortality than those non-ATT patients ( P = .035). There was only one death due to hemorrhage in the ATT group. This was unrelated to the tracheostomy. This compares to 2 hemorrhage-related deaths in those not on ATT. Conclusion: There was no significant difference in perioperative or postoperative bleeding based on ATT use. Patients on ATT were significantly more likely to experience 30-day mortality, however only one death was due to hemorrhage in the ATT group and was unrelated to tracheostomy. Therefore, continued perioperative ATT use appears to be safe when performing open tracheostomy. Level of Evidence: 4

Abstract IL-3, a pleiotropic lymphokine, has been termed mast cell growth factor because it promotes growth and differentiation of murine mast cells. Murine mast cells, in turn, express cell surface receptors for IL-3. Human rIL-3 has been shown to induce proliferation and differentiation of human basophils and to activate basophils via high affinity binding sites. To investigate whether human mast cells express IL-3R, binding studies with 125I-radiolabeled human rIL-3 were performed on HMC-1, a novel human mast cell line, and on pure populations (i.e., 93 to 99% purity) of human tissue mast cells obtained with mAb and C from dispersed lung (n = 2). Unexpectedly, neither enriched human lung mast cells nor HMC-1 cells bound radiolabeled human rIL-3 specifically. Moreover, human rIL-3 failed to promote uptake of [3H]thymidine, synthesis of histamine, histamine releasability, or changes in expression of mast cell differentiation Ag (YB5B8, CD54/ICAM-1, CD9/p24, CD33/gp67) on either human lung mast cells or HMC-1 cells. It is hypothesized that the fundamental difference in the biologic response to IL-3 between human and murine mast cells is due to a loss during evolution of mast cell high affinity IL-3 binding sites.

Abstract The mast cell is one of the major effector cells in inflammatory reactions and can be found in most tissues throughout the body. During inflammation, an increase in the number of mast cells can be seen, e.g., in the intraepithelial cell layer after a provoked allergic reaction. Such accumulation probably requires directed migration of mature mast cells or their precursors. To study the migration of human mast cells we used as a model the human mast cell line, HMC-1, and stem cell factor-dependent (also referred to as mast cell growth factor or Kit ligand) cord blood-derived mast cells. The results show that stem cell factor is a potent chemotactic factor for human mast cells in vitro. The chemotactic response to SCF was found to be dose dependent, reaching a maximum at 50 ng/ml. The activity of SCF could be blocked by anti-SCF Abs. We also tested the effect of different intercrines, i.e., IL-8, MIP-1 alpha, MIP-1 beta, RANTES, and MCAF (also referred to as monocyte chemotactic protein 1), on human mast cell migration. Only RANTES was chemotactic for in vitro-developed mast cells. None of the tested intercrines induced migration of HMC-1 cells. For migration, the mast cells were dependent on binding to an extracellular matrix protein. Thus, coating of the filters with fibronectin was required, whereas collagen or laminin did not promote migration. Adhesion of HMC-1 cells to fibronectin could also be shown in an adhesion assay. In addition, expression of receptors for fibronectin could be detected on the surface of the mast cells. These results show that SCF is not only a growth and differentiation factor for human mast cells in vitro but also a potent chemoattractant for such cells.

Abstract Modulation of expression of the c-kit proto-oncogene product, the receptor for the recently identified stem cell factor, was studied on 12-O-tetradecanoylphorbol-13-acetate (TPA)-stimulated cultures of CD34+ normal bone marrow progenitor cells, blast cells from patients with primary acute myelogenous leukemia, cells from the leukemia cell lines HEL and MO7E, as well as cultured HMC-1 mast cells. Expression of c-kit was assessed on both RNA and protein level employing standard Northern blotting, reverse transcription, and polymerase chain reaction-based Southern blotting, as well as cell surface labeling with anti-c-kit mAb YB5.B8. Treatment of virtually all cell types with nontoxic concentrations of TPA (10(-9) M) for at least 48 h was associated with down-regulation of synthesis of c-kit transcripts and stem cell factor-receptor surface expression. Studies on the mechanism of action of TPA utilizing the HEL erythroleukemia line showed that TPA was primarily acting by accelerating the turnover of c-kit RNA most likely through induction of a destabilizing protein. The effect of TPA on c-kit expression levels was independent of TPA-mediated induction of differentiation since other compounds including IFN-gamma, vitamin D3, retinoic acid, arabinofuranosylcytosine, butyric acid, and camptothecin, which also effectively induced differentiation of HEL cells, failed to alter levels of c-kit expression.

Abstract Background Despite the increasing incidence of neuroinvasive West Nile virus (NiWNV) infection in the US, the spectrum of disease characteristics and neuroimaging findings in immunosuppressed (IS) individuals are not adequately described. We aimed to compare the clinical characteristics and outcomes of NiWNV infection in IS and immunocompetent (IC) patients. Methods We extracted relevant data from all NiWNV patients hospitalized 7/2003-10/2021 at Mayo Clinic hospitals. Cohort was inclusive of patients from the recent historic WNV outbreak in Arizona in 2021. Chi-Square or Kruskal-Wallis and logistic regression were used to compare relevant variables and determine predictors of mortality respectively. Results We included 115 patients (72 IC and 43 IS), mean age 63.5 years; neurologic syndromes included meningoencephalitis (85.2%), encephalomyelitis (8.7%) and myeloradiculitis (6.1%). Presenting symptoms were malaise (72%), fever (66%), altered mentation (64%), gastrointestinal (47%) and myalgia (35.7%). MRI brain was abnormal in 62.8% (49/78), demonstrating T2/FLAIR hyperintensities in 47.4% (brainstem, thalamus, temporal lobes), leptomeningeal enhancement (16.7%) and diffusion restriction (20.5%). Altered mental status (76.7% vs 56.9%), myalgia (44.4% vs. 20.9%), myoclonus (18.6% vs. 4.2%) and thalamic MRI T2 FLAIR abnormalities (11.4% vs 0%) were more common in IS patients. Higher CSF WBC counts were observed in IC vs IS patients (P< 0.05). Immunosuppressed patients were more likely to be treated with intravenous immunoglobulin (44.2% vs 8.3% p=< 0.001) and/or interferon therapy (32.6% vs 6.9%, p=0.0003) and had increased odds of 90-day mortality on multivariable analysis (Adjusted Odds Ratio, AOR 2.22; 95% CI 1.065-4.627, p=0.0334). In the IS subgroup, ICU admission, mechanical ventilation, and Glasgow coma scale of < 8 were associated with reduced overall survival/increased 90-day mortality (p< 0.005). Conclusion Individuals presenting in summer/fall months with the aforementioned symptoms and/or MRI abnormalities should be evaluated for NiWNV infection. Compared to the immunocompetent, immunosuppressed patients with NiWNV are at a significantly greater mortality risk. Novel and effective antiviral therapies aimed at improving outcomes are warranted. Disclosures All Authors: No reported disclosures.

AbstractBackgroundNecrobiosis lipoidica (NL) is complicated by ulceration in up to 35% of cases.MethodsRetrospective study of patients with NL seen at our institution between January 1, 1992, and May 25, 2021, was conducted. Ulcerated NL (UNL, n = 83) and non‐ulcerated NL (NUNL, n = 233) groups were compared.ResultsTwenty‐six percent (83/316) of patients with NL experienced ulceration. UNL was significantly more likely to be painful (52% vs. 36%, P = 0.01), was more likely to have a lesion‐associated cutaneous malignancy (7% vs. 0%, P < 0.001), and had a larger median size (7 vs. 5 cm, P = 0.004) compared to NUNL. Vascular studies were performed on a subset of patients and revealed transcutaneous oxygen pressure (TcPO2) < 40 mm Hg in 53% and venous insufficiency in 62% with no significant differences between UNL and NUNL groups. In patients with unilateral ulceration, mean TcPO2 values (39.7 vs. 46.6 mm Hg), regional perfusion index <0.6 (29% vs. 14%), and TcPO2 < 40 mm Hg (43% vs. 14%) were worse in the ulcerated leg compared to the non‐ulcerated leg, but these differences were not statistically significant.ConclusionsUNL was more likely to be painful, develop lesion‐associated malignancy, and be larger in size compared to NUNL. There were no statistically significant differences in venous insufficiency, arterial Doppler/ankle brachial index, or TcPO2 values between UNL and NUNL patients, however, a significant portion of the cohort demonstrated abnormal vascular studies, particularly on TcPO2 and venous insufficiency testing.

Abstract Eosinophilia and eosinophil activation are recurrent features in various reactive states and certain hematologic malignancies. In patients with hypereosinophilia (HE), HE‐induced organ damage is often encountered and may lead to the diagnosis of a hypereosinophilic syndrome (HES). A number of known mechanisms and etiologies contribute to the development of HE and HES. Based on these etiologies and the origin of eosinophils, HE and HES are divided into primary forms where eosinophils are clonal cells, reactive forms where an underlying reactive or neoplastic condition is detected and eosinophils are considered to be “non‐clonal” cells, and idiopathic HE and HES in which neither a clonal nor a reactive underlying pathology is detected. Since 2012, this classification and the related criteria have been widely accepted and regarded as standard. However, during the past few years, new developments in the field and an increasing number of markers and targets have created a need to update these criteria and the classification of HE and HES. To address this challenge, a Working Conference on eosinophil disorders was organized in 2021. In this conference, a panel of experts representing the relevant fields, including allergy, dermatology, hematology, immunology, laboratory medicine, and pathology, met and discussed new markers and concepts as well as refinements in definitions, criteria and classifications of HE and HES. The outcomes of this conference are presented in this article and should assist in the diagnosis and management of patients with HE and HES in daily practice and in the preparation and conduct of clinical trials.

This cohort study examines factors that may contribute to whether patients address physicians differently through electronic messaging

Abstract Minimal residual disease (MRD) assays allow response assessment in patients with multiple myeloma (MM), and negativity is associated with improved survival outcomes. The role of highly sensitive next generation sequencing (NGS) MRD in combination with functional imaging remains to be validated. We performed a retrospective analysis on MM patients who underwent frontline autologous stem cell transplant (ASCT). Patients were evaluated at day 100 post-ASCT with NGS MRD and positron emission tomography (PET-CT). Patients with ≥ 2 MRD measurements were included in a secondary analysis for sequential measurements. 186 patients were included in the analysis. At day 100, 45 (24.2%) patients achieved MRD negativity at a sensitivity threshold of 10− 6. MRD negativity was the most predictive factor for longer time to next treatment (TTNT). Negativity rates did not differ according to MM subtype, R-ISS Stage nor cytogenetic risk. PET-CT and MRD positivity had poor agreement. Patients with sustained MRD negativity had longer TTNT, regardless of baseline risk characteristics. Our results show that the “real world” ability to measure deeper and sustainable responses distinguishes a subpopulation of patients with better outcomes. Achieving MRD negativity was the strongest prognostic marker and could help guide therapy-related decisions and serve as a response marker for clinical trials.