Development of tandem antigen capture ELISAs measuring QSOX1 isoforms in plasma and serum.

QSOX1 is a sulfhydryl oxidase that has been identified as a potential biomarker in multiple cancer types as well as acute decompensated heart failure. Three anti-QSOX1 monoclonal antibodies (mAbs) were generated: 2F1, 3A10, and 56-3. MAbs 2F1 and 3A10 were generated against the short isoform of recombinant QSOX1 (rQSOX1-S), and mAb 56-3 was generated against a peptide (NEQEQPLGQWHLS) from the long isoform of QSOX1 (QSOX1-L). Using these mAbs, tandem antigen capture ELISAs were developed to quantify both short and long isoforms of QSOX1 (Total QSOX1 ELISA) and QSOX1-L (QSOX1-L ELISA) in serum and plasma samples. The Total QSOX1 ELISA pairs mAbs 2F1 and 3A10 and has a limit of detection of 109.5 pM, while the QSOX1-L ELISA pairs mAbs 2F1 and 56-3 and has a limit of detection of 10 pM. The levels of total QSOX1 and QSOX1-L were measured in a cohort of paired sera and plasma from 61 donors ≥40 years old and 15 donors <40 years old. No difference in QSOX1 levels was detected between QSOX1-L and QSOX1-S in serum, but the mean concentration of QSOX1-L was found to be 3.21 nM in serum and 5.63 nM in plasma (**p = 0.006). Our tandem ELISAs demonstrate the wide range of concentrations of QSOX1-L and QSOX1-S among individual serum and plasma samples. Since the epitope of mAb 2F1 was mapped to the first CxxC motif at residues C70 and C73 and mAb 56-3 was generated against NEQEQPLGQWHLS in QSOX1-L, our findings support previous research which suggested that QSOX1-L is secreted from cells despite a putative transmembrane domain. The ELISAs reported here may be a useful tool for investigating QSOX1 isoforms as potential biomarkers in cancer and/or heart failure.

SETD2 loss in renal epithelial cells drives epithelial-to-mesenchymal transition in a TGF-ß-independent manner.

Histone-lysine N-methyltransferase SETD2 (SETD2), the sole histone methyltransferase that catalyzes trimethylation of lysine 36 on histone H3 (H3K36me3), is often mutated in clear cell renal cell carcinoma (ccRCC). SETD2 mutation and/or loss of H3K36me3 is linked to metastasis and poor outcome in ccRCC patients. Epithelial-to-mesenchymal transition (EMT) is a major pathway that drives invasion and metastasis in various cancer types. Here, using novel kidney epithelial cell lines isogenic for SETD2, we discovered that SETD2 inactivation drives EMT and promotes migration, invasion, and stemness in a transforming growth factor-beta-independent manner. This newly identified EMT program is triggered in part through secreted factors, including cytokines and growth factors, and through transcriptional reprogramming. RNA-seq and assay for transposase-accessible chromatin sequencing uncovered key transcription factors upregulated upon SETD2 loss, including SOX2, POU2F2 (OCT2), and PRRX1, that could individually drive EMT and stemness phenotypes in SETD2 wild-type (WT) cells. Public expression data from SETD2 WT/mutant ccRCC support the EMT transcriptional signatures derived from cell line models. In summary, our studies reveal that SETD2 is a key regulator of EMT phenotypes through cell-intrinsic and cell-extrinsic mechanisms that help explain the association between SETD2 loss and ccRCC metastasis.

Cardiorespiratory Monitoring Data to Predict Respiratory Outcomes in Extremely Preterm Infants.

Rationale: Immature control of breathing is associated with apnea, periodic breathing, intermittent hypoxemia, and bradycardia in extremely preterm infants. However, it is not clear if such events independently predict worse respiratory outcome. Objectives: To determine if analysis of cardiorespiratory monitoring data can predict unfavorable respiratory outcomes at 40 weeks postmenstrual age (PMA) and other outcomes, such as bronchopulmonary dysplasia at 36 weeks PMA. Methods: The Prematurity-related Ventilatory Control (Pre-Vent) study was an observational multicenter prospective cohort study including infants born at <29 weeks of gestation with continuous cardiorespiratory monitoring. The primary outcome was either "favorable" (alive and previously discharged or inpatient and off respiratory medications/O2/support at 40 wk PMA) or "unfavorable" (either deceased or inpatient/previously discharged on respiratory medications/O2/support at 40 wk PMA). Measurements and Main Results: A total of 717 infants were evaluated (median birth weight, 850 g; gestation, 26.4 wk), 53.7% of whom had a favorable outcome and 46.3% of whom had an unfavorable outcome. Physiologic data predicted unfavorable outcome, with accuracy improving with advancing age (area under the curve, 0.79 at Day 7, 0.85 at Day 28 and 32 wk PMA). The physiologic variable that contributed most to prediction was intermittent hypoxemia with oxygen saturation as measured by pulse oximetry <90%. Models with clinical data alone or combining physiologic and clinical data also had good accuracy, with areas under the curve of 0.84-0.85 at Days 7 and 14 and 0.86-0.88 at Day 28 and 32 weeks PMA. Intermittent hypoxemia with oxygen saturation as measured by pulse oximetry <80% was the major physiologic predictor of severe bronchopulmonary dysplasia and death or mechanical ventilation at 40 weeks PMA. Conclusions: Physiologic data are independently associated with unfavorable respiratory outcome in extremely preterm infants.

Generation and characterization of a monoclonal antibody that binds to Galectin-1.

Galectin-1 is a ß-galactoside-binding lectin that has been implicated as a suppressive molecule in cancer and autoimmune diseases. Gal-1 has known immunomodulatory activity and was found to be expressed on regulatory T cells, leading to the potential for targeted immunotherapies. Anti-Gal-1 monoclonal antibodies were generated in this study using classical hybridoma techniques. MAb 6F3 was found to bind to Gal-1 by Western blot and ELISA. Flow cytometry was used to determine cell surface and intracellular binding of mAb 6F3 to Gal-1 in PBMC-derived Tregs and tumor cells, including Treg-like cell lines. These results suggest mAb 6F3 may be used to further study Gal-1 protein expression and function.

Humanization and expression of IgG and IgM antibodies in plants as potential diagnostic reagents for Valley Fever.

Monoclonal antibodies (mAbs) are important proteins used in many life science applications, from diagnostics to therapeutics. High demand for mAbs for different applications urges the development of rapid and reliable recombinant production platforms. Plants provide a quick and inexpensive system for producing recombinant mAbs. Moreover, when paired with an established platform for mAb discovery, plants can easily be tailored to produce mAbs of different isotypes against the same target. Here, we demonstrate that a hybridoma-generated mouse mAb against chitinase 1 (CTS1), an antigen from Coccidioides spp., can be biologically engineered for use with serologic diagnostic test kits for coccidioidomycosis (Valley Fever) using plant expression. The original mouse IgG was modified and recombinantly produced in glycoengineered Nicotiana benthamiana plants via transient expression as IgG and IgM isotypes with human kappa, gamma, and mu constant regions. The two mAb isotypes produced in plants were shown to maintain target antigen recognition to CTS1 using similar reagents as the Food and Drug Administration (FDA)-approved Valley Fever diagnostic kits. As none of the currently approved kits provide antibody dilution controls, humanization of antibodies that bind to CTS1, a major component of the diagnostic antigen preparation, may provide a solution to the lack of consistently reactive antibody controls for Valley Fever diagnosis. Furthermore, our work provides a foundation for reproducible and consistent production of recombinant mAbs engineered to have a specific isotype for use in diagnostic assays.

Clinical Laboratory Utility of a Humanized Antibody in Commercially Available Enzyme Immunoassays for Coccidioidomycosis.

Coccidioidomycosis, also called valley fever (VF), is a fungal infection with endemicity in desert regions of the western United States as well as certain arid regions of Central and South America. Laboratory-based diagnosis of VF often relies on the composite results from three serologic-based diagnostics, complement fixation, immunodiffusion, and enzyme immunoassay (EIA). EIA is commonly performed in clinical laboratories because results can be obtained in a few hours. Two commercially available EIAs, IMMY clarus Coccidioides antibody and Meridian Premier Coccidioides, look for the presence of anticoccidioidal IgG and IgM in patient sera that are diluted 1:441. Per regulatory requirements, this dilution step must be verified with a dilution step control despite not being provided as a reagent in either FDA-approved EIA kit. Therefore, clinical laboratories collect and reuse patient sera in subsequent tests that had a positive result in a previous test. This is a nonstandard process, reinforcing the need for a consistent and reliable dilution control. Here, we evaluate the performance of a humanized IgG and IgM antibody as a dilution control in both EIA kits. Both humanized IgG and IgM work well in each EIA and meet the appropriate threshold for positivity. IMPORTANCE In southwestern and western regions of the United States, at least half a million diagnostic tests for coccidioidomycosis (valley fever) are run annually. Enzyme immunoassays (EIAs) are blood tests which require precise dilution of patient serum prior to testing. To ensure patient serum is properly diluted, there is a regulatory requirement to ensure the dilution step is accurate. Two FDA-approved EIAs used to aid in the diagnosis of coccidioidomycosis do not contain controls for this dilution step, leaving clinical laboratories with the only option of using previously positive patient sera, which may not react in a reliable or predictable manner. Here, we evaluate a humanized monoclonal antibody against a coccidioidal antigen and its utility as a dilution control in both available commercial EIAs. The use of a humanized monoclonal antibody provides a standardized and well-characterized dilution control for use in serological assays that aid in diagnosis of coccidioidomycosis.

Potential for a Plant-Made SARS-CoV-2 Neutralizing Monoclonal Antibody as a Synergetic Cocktail Component.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a public health crisis over the last two years. Monoclonal antibody (mAb)-based therapeutics against the spike (S) protein have been shown to be effective treatments for SARS-CoV-2 infection, especially the original viral strain. However, the current mAbs produced in mammalian cells are expensive and might be unaffordable for many. Furthermore, the emergence of variants of concern demands the development of strategies to prevent mutant escape from mAb treatment. Using a cocktail of mAbs that bind to complementary neutralizing epitopes is one such strategy. In this study, we use Nicotiana benthamiana plants in an effort to expedite the development of efficacious and affordable antibody cocktails against SARS-CoV-2. We show that two mAbs can be highly expressed in plants and are correctly assembled into IgG molecules. Moreover, they retain target epitope recognition and, more importantly, neutralize multiple SARS-CoV-2 variants. We also show that one plant-made mAb has neutralizing synergy with other mAbs that we developed in hybridomas. This is the first report of a plant-made mAb to be assessed as a potential component of a SARS-CoV-2 neutralizing cocktail. This work may offer a strategy for using plants to quickly develop mAb cocktail-based therapeutics against emerging viral diseases with high efficacy and low costs.

Identification of a CD4+ T cell line with Treg-like activity.

Regulatory T cells (Tregs) suppress adaptive immunity and inflammation. Although they play a role in suppressing anti-tumor responses, development of therapeutics that target Tregs is limited by their low abundance, heterogeneity, and lack of specific cell surface markers. We isolated human PBMC-derived CD4+ CD25high Foxp3+ Tregs and demonstrate they suppress stimulated CD4+ PBMCs in a cell contact-dependent manner. Because it is not possible to functionally characterize cells after intracellular Foxp3 staining, we identified a human T cell line, MoT, as a model of human Foxp3+ Tregs. Unlike Jurkat T cells, MoT cells share common surface markers consistent with human PBMC-derived Tregs such as: CD4, CD25, GITR, LAG-3, PD-L1, CCR4. PBMC-derived Tregs and MoT cells, but not Jurkat cells, inhibited proliferation of human CD4+PBMCs in a ratio-dependent manner. Transwell membrane separation prevented suppression of stimulated CD4+PBMC proliferation by MoT cells and Tregs, suggesting cell-cell contact is required for suppressive activity. Blocking antibodies against PD-L1, LAG-3, GITR, CCR4, HLA-DR, or CTLA-4 did not reverse the suppressive activity.We show that human PBMC-derived Tregs and MoT cells suppress stimulated CD4+PBMCs in a cell contact-dependent manner, suggesting that a Foxp3+Treg population suppresses immune responses by an uncharacterized cell contact-dependent mechanism.

Heart rate fragmentation gives novel insights into non-autonomic mechanisms governing beat-to-beat control of the heart's rhythm.

To demonstrate how heart rate fragmentation gives novel insights into non-autonomic mechanisms of beat-to-beat variability in cycle length, and predicts survival of cardiology clinic patients, over and above traditional clinical risk factors and measures of heart rate variability. Approach: We studied 2893 patients seen by cardiologists with clinical data including 24-hour Holter monitoring. Novel measures of heart rate fragmentation alongside canonical time and frequency domain measures of heart rate variability, as well as an existing local dynamics score were calculated. A proportional hazards model was utilized to relate the results to survival. Main results: The novel heart rate fragmentation measures were validated and characterized with respect to the effects of age, ectopy and atrial fibrillation. Correlations between parameters were determined. Critically, heart rate fragmentation results could not be accounted for by undersampling respiratory sinus arrhythmia. Increased heart rate fragmentation was associated with poorer survival (p ≪ 0.01 in the univariate model). In multivariable analyses, increased heart rate fragmentation and more abnormal local dynamics (p 0.045), along with increased clinical risk factors (age (p ≪ 0.01), tobacco use (p ≪ 0.01) and history of heart failure (p 0.019)) and lower low- to high-frequency ratio (p 0.022) were all independent predictors of 2-year mortality. Significance: Analysis of continuous ECG data with heart rate fragmentation indices yields information regarding non-autonomic control of beat-to-beat variability in cycle length that is independent of and additive to established parameters for investigating heart rate variability, and predicts mortality in concert with measures of local dynamics, frequency content of heart rate, and clinical risk factors.

Correction: Oxygen desaturations in the early neonatal period predict development of bronchopulmonary dysplasia.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Towards development of alert thresholds for clinical deterioration using continuous predictive analytics monitoring.

Patients who deteriorate while on the acute care ward and are emergently transferred to the Intensive Care Unit (ICU) experience high rates of mortality. To date, risk scores for clinical deterioration applied to the acute care wards rely on static or intermittent inputs of vital sign and assessment parameters. We propose the use of continuous predictive analytics monitoring, or data that relies on real-time physiologic monitoring data captured from ECG, documented vital signs, laboratory results, and other clinical assessments to predict clinical deterioration. A necessary step in translation to practice is understanding how an alert threshold would perform if applied to a continuous predictive analytic that was trained to detect clinical deterioration. The purpose of this study was to evaluate the positive predictive value of 'risk spikes', or large abrupt increases in the output of a statistical model of risk predicting clinical deterioration. We studied 8111 consecutive patient admissions to a cardiovascular medicine and surgery ward with continuous ECG data. We first trained a multivariable logistic regression model for emergent ICU transfer in a test set and tested the characteristics of the model in a validation set of 4059 patient admissions. Then, in a nested analysis we identified large, abrupt spikes in risk (increase by three units over the prior 6 h; a unit is the fold-increase in risk of ICU transfer in the next 24 h) and reviewed hospital records of 91 patients for clinical events such as emergent ICU transfer. We compared results to 59 control patients at times when they were matched for baseline risk including the National Warning Score (NEWS). There was a 3.4-fold higher event rate for patients with risk spikes (positive predictive value 24% compared to 7%, p = 0.006). If we were to use risk spikes as an alert, they would fire about once per day on a 73-bed acute care ward. Risk spikes that were primarily driven by respiratory changes (ECG-derived respiration (EDR) or charted respiratory rate) had highest PPV (30-35%) while risk spikes driven by heart rate had the lowest (7%). Alert thresholds derived from continuous predictive analytics monitoring are able to be operationalized as a degree of change from the person's own baseline rather than arbitrary threshold cut-points, which can likely better account for the individual's own inherent acuity levels. Point of care clinicians in the acute care ward settings need tailored alert strategies that promote a balance in recognition of clinical deterioration and assessment of the utility of the alert approach.

Molecular Inhibitor of QSOX1 Suppresses Tumor Growth In Vivo.

Quiescin sulfhydryl oxidase 1 (QSOX1) is an enzyme overexpressed by many different tumor types. QSOX1 catalyzes the formation of disulfide bonds in proteins. Because short hairpin knockdowns (KD) of QSOX1 have been shown to suppress tumor growth and invasion in vitro and in vivo, we hypothesized that chemical compounds inhibiting QSOX1 enzymatic activity would also suppress tumor growth, invasion, and metastasis. High throughput screening using a QSOX1-based enzymatic assay revealed multiple potential QSOX1 inhibitors. One of the inhibitors, known as "SBI-183," suppresses tumor cell growth in a Matrigel-based spheroid assay and inhibits invasion in a modified Boyden chamber, but does not affect viability of nonmalignant cells. Oral administration of SBI-183 inhibits tumor growth in 2 independent human xenograft mouse models of renal cell carcinoma. We conclude that SBI-183 warrants further exploration as a useful tool for understanding QSOX1 biology and as a potential novel anticancer agent in tumors that overexpress QSOX1.

Pre-Vent: the prematurity-related ventilatory control study.

BACKGROUND: The increasing incidence of bronchopulmonary dysplasia in premature babies may be due in part to immature ventilatory control, contributing to hypoxemia. The latter responds to ventilation and/or oxygen therapy, treatments associated with adverse sequelae. This is an overview of the Prematurity-Related Ventilatory Control Study which aims to analyze the under-utilized cardiorespiratory continuous waveform monitoring data to delineate mechanisms of immature ventilatory control in preterm infants and identify predictive markers. METHODS: Continuous ECG, heart rate, respiratory, and oxygen saturation data will be collected throughout the NICU stay in 500 infants < 29 wks gestation across 5 centers. Mild permissive hypercapnia, and hyperoxia and/or hypoxia assessments will be conducted in a subcohort of infants along with inpatient questionnaires, urine, serum, and DNA samples. RESULTS: Primary outcomes will be respiratory status at 40 wks and quantitative measures of immature breathing plotted on a standard curve for infants matched at 36-37 wks. Physiologic and/or biologic determinants will be collected to enhance the predictive model linking ventilatory control to outcomes. CONCLUSIONS: By incorporating bedside monitoring variables along with biomarkers that predict respiratory outcomes we aim to elucidate individualized cardiopulmonary phenotypes and mechanisms of ventilatory control contributing to adverse respiratory outcomes in premature infants.

Loss of SETD2 Induces a Metabolic Switch in Renal Cell Carcinoma Cell Lines toward Enhanced Oxidative Phosphorylation.

SETD2, a histone H3 lysine trimethyltransferase, is frequently inactivated and associated with recurrence of clear cell renal cell carcinoma (ccRCC). However, the impact of SETD2 loss on metabolic alterations in ccRCC is still unclear. In this study, SETD2 null isogenic 38E/38F clones derived from 786-O cells were generated by zinc finger nucleases, and subsequent metabolic, genomic, and cellular phenotypic changes were analyzed by targeted metabolomics, RNA sequencing, and biological methods, respectively. Our results showed that compared with parental 786-O cells, 38E/38F cells had elevated levels of MTT/Alamar blue levels, ATP, glycolytic/mitochondrial respiratory capacity, citrate synthase (CS) activity, and TCA metabolites such as aspartate, malate, succinate, fumarate, and α-ketoglutarate. The 38E/38F cells also utilized alternative sources beyond pyruvate to generate acetyl-CoA for the TCA cycle. Moreover, 38E/38F cells showed disturbed gene networks mainly related to mitochondrial metabolism and the oxidation of fatty acids and glucose, which was associated with increased PGC1α, mitochondrial mass, and cellular size/complexity. Our results indicate that SETD2 deficiency induces a metabolic switch toward enhanced oxidative phosphorylation in ccRCC, which can be related to PGC1α-mediated metabolic networks. Therefore, this current study lays the foundation for the further development of a global metabolic analysis of cancer cells in individual patients, which ultimately will have significant potential for the discovery of novel therapeutics and precision medicine in SETD2-inactivated ccRCC.

Oxygen desaturations in the early neonatal period predict development of bronchopulmonary dysplasia.

BACKGROUND: Bradycardia and oxygen desaturation episodes are common among preterm very low birth weight (VLBW) infants in the Neonatal Intensive Care Unit (NICU), and their association with adverse outcomes such as bronchopulmonary dysplasia (BPD) is unclear. METHODS: For 502 VLBW infants we quantified bradycardias (HR < 100 for ≥ 4 s) and desaturations (SpO2 < 80% for ≥ 10 s), combined bradycardia and desaturation (BD) events, and percent time in events in the first 4 weeks after birth (32 infant-years of data). We tested logistic regression models of clinical risks (including a respiratory acuity score incorporating FiO2 and level of respiratory support) to estimate the risks of BPD or death and secondary outcomes. We then tested the additive value of the bradycardia and desaturation metrics for outcomes prediction. RESULTS: BPD occurred in 187 infants (37%). The clinical risk model had ROC area for BPD of 0.874. Measures of desaturation, but not bradycardia, significantly added to the predictive model. Desaturation metrics also added to clinical risks for prediction of severe intraventricular hemorrhage, retinopathy of prematurity and prolonged length of stay in the NICU. CONCLUSIONS: Oxygen desaturations in the first month of the NICU course are associated with risk of BPD and other morbidities in VLBW infants.

Correction to: Expression of quiescin sulfhydryl oxidase 1 is associated with a highly invasive phenotype and correlates with a poor prognosis in luminal B breast cancer.

After the publication of this work [1], an error was noticed in Fig. 4a. The micrograph image sh528 was accidentally duplicated.

Identifying the low risk patient in surgical intensive and intermediate care units using continuous monitoring.

BACKGROUND: Continuous predictive monitoring has been employed successfully to predict subclinical adverse events. Should low values on these models, however, reassure us that a patient will not have an adverse outcome? Negative predictive values of such models could help predict safe patient discharge. The goal of this study was to validate the negative predictive value of an ensemble model for critical illness (using previously developed models for respiratory instability, hemorrhage, and sepsis) based on bedside monitoring data in the intensive care units and intermediate care unit. METHODS: We calculated the relative risk of 3 critical illnesses for all patients every 15 minutes (n= 124,588) for 2,924 patients downgraded from the surgical intensive care units and intermediate care unit between May 2014 to May 2016. We constructed an ensemble model to estimate at the time of intensive care units or intermediate care unit discharge the probability of favorable outcome after downgrade. RESULTS: Outputs form the ensemble model stratified patients by risk of favorable and bad outcomes in both intensive care units/intermediate care unit; area under the receiver operating characteristic curve = .639/.629 respectively for favorable outcomes and .645/.641 for adverse events. These performance characteristics are commensurate with published models for predicting readmission. The ensemble model remained a statistically significant predictor after adjusting for hospital duration of stay and admitting service. The rate of favorable outcome in the highest and lowest deciles in the intensive care units were 76.2% and 27.3% (2.8-fold decrease) and 88.3% and 33.2% in the intermediate care unit (2.7-fold decrease), respectively. CONCLUSION: An ensemble model for critical illness predicts favorable outcome after downgrade and safe patient discharge (hospital stay <7 days, no readmission, upgrade, or death).

Insights on the HLA-Binding Peptidome in Cancer.

The intracellular compartments for proteolytic antigen processing in tumor cells produce peptides that are presented by MHC molecules to T cells. But first, the ubiquitin ligase system tags defective, misfolded, aged, and unstable proteins for degradation through the proteasome. Ubiqitinated proteins are unfolded and fed into the barrel-shaped core of the proteasome where a collection of multiple different proteases cleave proteins into oligopeptides. After exiting the proteasome, these oligopeptides are either completely degraded into amino acids or trimmed at the N- and C-termini so that they bind to transporter associated with antigen processing (TAP). TAP translocates oligopeptides into the ER where they are further trimmed and may bind to MHC molecules. Resulting peptide-MHC complexes then travel to the cell surface for T cell recognition. Many defects or anomalies in the proteolytic processing of tumor-derived proteins may suppress the expression of peptide-MHC complexes, which plays a role in escape of tumors from the immune system. However, due to the general dysregulated intracellular machinery of tumors, many proteins are translated from unconventional RNA transcripts including noncoding RNA, exon-intron retentions, and alternative splicing. These products of translation can serve as novel peptides for T cells as they recognize and kill tumors.

Hemorrhage Prediction Models in Surgical Intensive Care: Bedside Monitoring Data Adds Information to Lab Values.

Hemorrhage is a frequent complication in surgery patients; its identification and management have received increasing attention as a target for quality improvement in patient care in the Intensive Care Unit (ICU). The purposes of this work were 1) to find an early detection model for hemorrhage by exploring the range of data mining methods that are currently available, and 2) to compare prediction models utilizing continuously measured physiological data from bedside monitors to those using commonly obtained laboratory tests. We studied 3766 patients admitted to the University of Virginia Health System Surgical Trauma Burn ICU. Hemorrhage was defined as three or more units of red blood cells transfused within 24 h without red blood cell transfusion in the preceding 24 h. 222 patients (5.9%) experienced a hemorrhage, and multivariate models based on vital signs and their trends showed good results (AUC = 76.1%). The hematocrit, not surprisingly, had excellent performance (AUC = 87.7%). Models that included both continuous monitoring and laboratory tests had the best performance (AUC = 92.2%). The results point to a combined strategy of continuous monitoring and intermittent lab tests as a reasonable clinical approach to the early detection of hemorrhage in the surgical ICU.

External validation in an intermediate unit of a respiratory decompensation model trained in an intensive care unit.

BACKGROUND: Preventing urgent intubation and upgrade in level of care in patients with subclinical deterioration could be of great utility in hospitalized patients. Early detection should result in decreased mortality, duration of stay, and/or resource use. The goal of this study was to externally validate a previously developed, vital sign-based, intensive care unit, respiratory instability model on a separate population, intermediate care patients. METHODS: From May 2014 to May 2016, the model calculated relative risk of adverse events every 15 minutes (n = 373,271 observations) for 2,050 patients in a surgical intermediate care unit. RESULTS: We identified 167 upgrades and 57 intubations. The performance of the model for predicting upgrades within 12 hours was highly significant with an area under the curve of 0.693 (95% confidence interval, 0.658-0.724). The model was well calibrated with relative risks in the highest and lowest deciles of 2.99 and 0.45, respectively (a 6.6-fold increase). The model was effective at predicting intubation, with a demonstrated area under the curve within 12 hours of the event of 0.748 (95% confidence interval, 0.685-0.800). The highest and lowest deciles of observed relative risk were 3.91 and 0.39, respectively (a 10.1-fold increase). Univariate analysis of vital signs showed that transfer upgrades were associated, in order of importance, with rising respiration rate, rising heart rate, and falling pulse-oxygen saturation level. CONCLUSION: The respiratory instability model developed previously is valid in intermediate care patients to predict both urgent intubations and requirements for upgrade in level of care to an intensive care unit.