Preliminary Report for the Development of a Multiparameter Protocol for the Identification of Sinusoidal Obstruction Syndrome including Abdominal Ultrasound before and after Allogeneic Stem Cell Transplantation

Sinusoidal obstruction syndrome (SOS) is a rare complication after allogeneic hematopoietic stem cell transplantation (alloHSCT) caused by endothelial dysfunction. Previous definitions and diagnostic criteria for the presence of SOS include bilirubinemia, hepatomegaly and weight gain, but histological evaluation is still the only way to prove the diagnosis of SOS. However, biopsy remains an invasive technique and is therefore undesirable in the alloHSCT scenario. Hence, a non-invasive diagnostic strategy is critical. Besides thorough clinical assessment and laboratory values, ultrasound examination remains part of the diagnostic workflow in clinical routine. Previous studies defined sonographic abnormalities, which are associated with the occurrence of SOS, but a standardized protocol to perform reliable abdominal ultrasound has not been finally defined. In this study, we evaluated a multi-parameter protocol including laboratory values as well as ultrasound examination pre- and post-alloHSCT. The application of this protocol was feasible in clinical practice and achieved a high inter- and intra-rater reliability. In our population, no case of SOS was identifiable and, in line with previous studies, no changes known to be associated with SOS were detected by ultrasound examination in our cohort. Additionally, we investigated subgroups of patients partly fulfilling SOS diagnostic criteria analyzing correlations between the fulfilled criteria and aberrances in ultrasound measurements pre- and post-alloHSCT. Although statistical examination may be limited by a small sample size and missing SOS cases, hyperbilirubinemia, thrombocytopenia and weight gain showed only a coincidence with selected, enlarged liver dimensions in few patients. This may underline the fact that hepatomegaly occurs as an unspecific finding after alloHSCT. Our protocol, including the ultrasound examination pre- and post-alloHSCT and laboratory parameters, may help to rule out SOS early, but validation in a greater population and different transplantation centers is required to warrant broader appliance. Nevertheless, we aim to contribute to an elaborate and standardized work-flow in peri-alloHSCT patient care.

Relationship between Pneumonia and the Thymus Gland in Children with COVID-19: A Volumetric Computed Tomography Study

Objective Many studies showed that less-severe disease symptoms and fewer mortality rates have been reported in pediatric novel coronavirus disease 2019 (COVID-19) patients. In this study, we aimed to reveal the relationship between the volume of thymus gland, which provides T lymphocyte maturation in children, with the severity of lung involvement and blood laboratory values in pediatric patients with COVID-19 infection. Methods Thymus density and thymus and cardiac volumes were measured in pediatric COVID-19 patients and a control group that underwent thoracic tomography for reasons other than infection. Thymus/heart ratios were calculated to index the thymus volumes of the patients to their body dimensions. The severity of pneumonia was demonstrated by proportioning the involved lung parenchymal volume to the total lung volume in patients with typical involvement in thoracic tomography. The relationship between volumetric and blood laboratory values was statistically evaluated. Results Thymus density (p = 0.015) and thymus/heart ratio (p = 0.04) significantly differed between patients with COVID-19 infection and the control group. A correlation was observed between the pneumonia involvement rate and C-reactive protein (CRP) (k: 0.451, p = 0.08) and white blood cell (WBC; k: 0.419, p = 0.015) values in the thoracic tomography of the COVID-19 group. Conclusion The thymus gland is enlarged as an indicator of activation in COVID-19 infection. We hope that our study will guide new studies on the prognostic value of thymus size in lymphopenic patients with severe disease.

Machine Learning Approach Using Routine Immediate Postoperative Laboratory Values for Predicting Postoperative Mortality

Background: Several prediction models have been proposed for preoperative risk stratification for mortality. However, few studies have investigated postoperative risk factors, which have a significant influence on survival after surgery. This study aimed to develop prediction models using routine immediate postoperative laboratory values for predicting postoperative mortality. Methods: Two tertiary hospital databases were used in this research: one for model development and another for external validation of the resulting models. The following algorithms were utilized for model development: LASSO logistic regression, random forest, deep neural network, and XGBoost. We built the models on the lab values from immediate postoperative blood tests and compared them with the SASA scoring system to demonstrate their efficacy. Results: There were 3817 patients who had immediate postoperative blood test values. All models trained on immediate postoperative lab values outperformed the SASA model. Furthermore, the developed random forest model had the best AUROC of 0.82 and AUPRC of 0.13, and the phosphorus level contributed the most to the random forest model. Conclusions: Machine learning models trained on routine immediate postoperative laboratory values outperformed previously published approaches in predicting 30-day postoperative mortality, indicating that they may be beneficial in identifying patients at increased risk of postoperative death.

Identification of Endotypes of Hospitalized COVID-19 Patients

Background: Characterization of coronavirus disease 2019 (COVID-19) endotypes may help explain variable clinical presentations and response to treatments. While risk factors for COVID-19 have been described, COVID-19 endotypes have not been elucidated.Objectives: We sought to identify and describe COVID-19 endotypes of hospitalized patients.Methods: Consensus clustering (using the ensemble method) of patient age and laboratory values during admission identified endotypes. We analyzed data from 528 patients with COVID-19 who were admitted to telemetry capable beds at Columbia University Irving Medical Center and discharged between March 12 to July 15, 2020.Results: Four unique endotypes were identified and described by laboratory values, demographics, outcomes, and treatments. Endotypes 1 and 2 were comprised of low numbers of intubated patients (1 and 6%) and exhibited low mortality (1 and 6%), whereas endotypes 3 and 4 included high numbers of intubated patients (72 and 85%) with elevated mortality (21 and 43%). Endotypes 2 and 4 had the most comorbidities. Endotype 1 patients had low levels of inflammatory markers (ferritin, IL-6, CRP, LDH), low infectious markers (WBC, procalcitonin), and low degree of coagulopathy (PTT, PT), while endotype 4 had higher levels of those markers.Conclusions: Four unique endotypes of hospitalized patients with COVID-19 were identified, which segregated patients based on inflammatory markers, infectious markers, evidence of end-organ dysfunction, comorbidities, and outcomes. High comorbidities did not associate with poor outcome endotypes. Further work is needed to validate these endotypes in other cohorts and to study endotype differences to treatment responses.

"Ideal" PTH in ESA-Resistant Anemia

Background: Anemia is a nearly universal complication of End Stage Renal Disease (ESRD). Erythropoiesis-stimulating agents (ESAs) have greatly decreased transfusion dependence in the anemia of ESRD. In some cases, ESAs are not effective, indicating ESA-resistance. ESA-resistant anemia is not well characterized and can be difficult to manage. Among the most frequent causes of ESA-resistant anemia is secondary hyperparathyroidism (SHP), which can induce bone marrow remodeling and fibrosis. Treatment protocols in SHP are centered on goal calcium, phosphorus and parathyroid hormone (PTH) levels and not the biologic consequences of high PTH. The hematologic insults secondary to SHP are rarely addressed. Instead, it is common to simply increase ESA dosing, rather than address the cause of ESA-resistance. In this retrospective review, we describe a cohort of patients with ESRD and SHP and highlight in detail one patient with reversible bone marrow changes and transfusion-dependent anemia, as well as descriptive and laboratory findings of bone marrow changes in patients with anemia and ESRD referred to our center. Methods: Using the EMR, the patient's data including demographics, progress notes, laboratory values, and bone marrow findings were extracted. Subsequently, the EMR was interrogated to reveal all patients with anemia and ESRD, who had undergone a bone marrow biopsy at out center over a ten year period from 2010 to 2020, revealing 64 patients. Data including demographics, laboratory values, bone marrow findings, and medications were extracted. Data was presented descriptively. Results: A 67-year-old male with ESRD secondary to hypertension and type 2 diabetes was referred to our Hematology clinic for anemia of ESRD. He was receiving Epoetin 20,000 IU three times weekly but was still transfusion-dependent to maintain a hemoglobin of 6.3 g/dL, with a concomitant PTH of 400.5 pg/mL. Calcium and phosphorus were normal and thus his SHP was not aggressively managed. Bone marrow biopsy revealed focal areas of bone marrow remodeling and reticulin fibrosis. Fluorescence in situ hybridization studies for myelodysplastic syndrome were negative, as were thyroid studies, serum protein electrophoresis, and free light chain ratio. In conjunction with his nephrologist, treatment of his SHP was optimized. His initial regimen was calcitriol 0.25 mcg once daily and calcium acetate 667 mg three times daily. Subsequently, cinacalcet 30 mg twice daily was added and calcium acetate was replaced with sevelamer 1600 mg three times daily. Following these changes, his hemoglobin remained stable in the range of 8-9 g/dL. He was no longer transfusion-dependent, despite only a modest reduction in PTH to 311.2 pg/mL. Repeat bone marrow biopsy revealed no bone marrow remodeling or reticulin fibrosis. Bone marrow findings for all patients referred to our clinic with ESRD and anemia are summarized in Table 1. The range of PTH for patients with bony remodeling was 183-16161.9 pg/mL versus 90.8-3283 pg/mL for those without bony remodeling. The range of PTH for patients with fibrotic changes was 183-2487 pg/mL versus 90.8-16161.9 pg/mL for those without fibrotic changes. ESA dosing varied among the patients. Conclusion: SHP is an increasingly identifiable cause of ESA-resistant anemia, as demonstrated by the reversal of transfusion dependence in our patient once SHP was more adequately treated. The degree of reversible ESA-resistant anemia and transfusion dependence in the setting of a PTH elevation to 400.5 in this case is surprising. The great variability in PTH levels of patients both with and without bone marrow changes presented here indicates the relationship between SHP and anemia is intricate. A single target level for the whole dialysis population is not appropriate; neither is targeting only and the same goal calcium, phosphorus, and PTH levels for the whole dialysis population either. Based on the findings of our institutional cohort, we suggest that it is justified to deviate from "on-size-fits-all" protocols and attempt a trial of aggressive management of SHP in patients with difficult to manage ESA-resistant anemia with what is considered only modest PTH elevation. Figure 1 Figure 1. Disclosures Moe: Allena Pharmaceutical: Consultancy; Janssen: Consultancy; Alnylum: Consultancy; DIcerna: Consultancy; Tricida: Consultancy.

Preoperative evaluation of coagulation status in neuromodulation patients

OBJECTIVE The incidence of hemorrhage in patients who undergo deep brain stimulation (DBS) and spinal cord stimulation (SCS) is between 0.5% and 2.5%. Coagulation status is one of the factors that can predispose patients to the development of these complications. As a routine part of preoperative assessment, the authors obtain prothrombin time (PT), partial thromboplastin time (PTT), and platelet count. However, insurers often cover only PT/PTT laboratory tests if the patient is receiving warfarin/heparin. The authors aimed to examine their experience with abnormal coagulation parameters in patients who underwent neuromodulation. METHODS Patients who underwent neuromodulation (SCS, DBS, or intrathecal pump implantation) over a 9-year period and had preoperative laboratory values available were included. The authors determined abnormal values on the basis of a clinical protocol utilized at their practice, which combined the normal ranges of the laboratory tests and clinical relevance. This protocol had cutoff values of 12 seconds and 39 seconds for PT and PTT, respectively, and < 120,000 platelets/μl. The authors identified risk factors for these abnormalities and described interventions. RESULTS Of the 1767 patients who met the inclusion criteria, 136 had abnormal preoperative laboratory values. Five of these 136 patients had values that were misclassified as abnormal because they were within the normal ranges at the outside facility where they were tested. Fifty-one patients had laboratory values outside the ranges of our protocol, but the surgeons reviewed and approved these patients without further intervention. Of the remaining 80 patients, 8 had known coagulopathies and 24 were receiving warfarin/heparin. The remaining 48 patients were receiving other anticoagulant/antiplatelet medications. These included apixaban/rivaroxaban/dabigatran anticoagulants (n = 22; mean ± SD PT 13.7 ± 2.5 seconds) and aspirin/clopidogrel/other antiplatelet medications (n = 26; mean ± SD PT 14.4 ± 5.8 seconds). Eight new coagulopathies were identified and further investigated with hematological analysis. CONCLUSIONS New anticoagulants and antiplatelet medications are not monitored with PT/PTT, but they affect coagulation status and laboratory values. Although platelet function tests aid in a subset of medications, it is more difficult to assess the coagulation status of patients receiving novel anticoagulants. PT/PTT may provide value preoperatively.

488. Comparison of Demographics and Clinical Characteristics of Multisystem Inflammatory Syndrome in Children and Kawasaki Disease

Background Multisystem inflammatory syndrome in children (MIS-C) is an illness associated with recent SARS-CoV-2 infection or exposure. Kawasaki disease (KD), a vasculitis with an unknown etiology, has overlapping clinical presentation with MIS-C, making it difficult to clinicians for distinguish between them. Therefore, we aimed to compare demographic, laboratory, and clinical characteristics between MIS-C and KD in hospitalized children in Nashville, TN. Methods We conducted a single-center retrospective chart review for hospitalized children under 18 years who met American Heart Association criteria for KD and were treated with intravenous immunoglobulin from May 2000 to December 2019, and children meeting the CDC criteria for MIS-C from July 2020 to May 2021. Data abstraction for patients’ demographics, clinical presentation, laboratory values and imaging results was performed. Pearson’s chi-squared test for categorical variables and Wilcoxon rank sum test for continuous variables, with alpha=5%, were used to compare groups. Results A total of 603 KD and 52 MIS-C hospitalized patients were included. Children with MIS-C were older than those with KD. A higher frequency of male sex was noted in both groups, with no significant differences in race and ethnicity (Table). MIS-C children frequently presented with symptoms similar to KD (63.5% rash, 55.8% conjunctivitis, 28.9% mucous membrane changes); however, only one MIS-C patient met criteria for complete KD (Figure). Both MIS-C and KD children presented with elevated CRP and ESR, but the median value of CRP in MIS-C children was significantly higher (Table). In addition, white cell count was lower in MIS-C children, which is primarily driven by the lower absolute lymphocyte count in this group (0.9 vs 2.7, p&lt; 0.001), and echocardiography was more likely to be abnormal at presentation compared to KD (Table). Table. Comparison of Sociodemographic, Clinical, and Laboratory Characteristics among Children with Kawasaki Disease and Multisystem Inflammatory Syndrome in Nashville Figure. Comparison of Kawasaki Criteria Between Children with Multisystem Inflammatory Syndrome and Kawasaki Disease Conclusion MIS-C and KD present similarly in children; however, age, laboratory and echocardiography findings can help differentiate between them. Different laboratory values suggest different pathophysiology and inflammatory mediators behind these two illnesses, warranting further research. Disclosures Natasha B. Halasa, MD, MPH, Genentech (Other Financial or Material Support, I receive an honorarium for lectures - it’s a education grant, supported by genetech)Quidel (Grant/Research Support, Other Financial or Material Support, Donation of supplies/kits)Sanofi (Grant/Research Support, Other Financial or Material Support, HAI/NAI testing) Natasha B. Halasa, MD, MPH, Genentech (Individual(s) Involved: Self): I receive an honorarium for lectures - it’s a education grant, supported by genetech, Other Financial or Material Support, Other Financial or Material Support; Sanofi (Individual(s) Involved: Self): Grant/Research Support, Research Grant or Support