A correlative study of the genomic underpinning of virulence traits and drug tolerance of Candida auris.

Candida auris is an opportunistic fungal pathogen with high mortality rates which presents a clear threat to public health. The risk of C. auris infection is high because it can colonize the body, resist antifungal treatment, and evade the immune system. The genetic mechanisms for these traits are not well known. Identifying them could lead to new targets for new treatments. To this end, we present an analysis of the genetics and gene expression patterns of C. auris carbon metabolism, drug resistance, and macrophage interaction. We chose to study two C. auris isolates simultaneously, one drug sensitive (B11220 from Clade II) and one drug resistant (B11221 from Clade III). Comparing the genomes, we confirm the previously reported finding that B11220 was missing a 12.8 kb region on chromosome VI. This region contains a gene cluster encoding proteins related to alternative sugar utilization. We show that B11221, which has the gene cluster, readily assimilates and utilizes D-galactose and L-rhamnose as compared to B11220, which harbors the deletion. B11221 exhibits increased adherence and drug resistance compared to B11220 when grown in these sugars. Transcriptomic analysis of both isolates grown on glucose or galactose showed that the gene cluster was upregulated when grown on D-galactose. These findings reinforce growing evidence of a link between metabolism and drug tolerance. B11221 resists phagocytosis by macrophages and exhibits decreased ß-1,3-glucan exposure, a key determinant that allows Candida to evade the host immune system, as compared to B11220. In a transcriptomic analysis of both isolates co-cultured with macrophages, we find upregulation of genes associated with transport and transcription factors in B11221. Our studies show a positive correlation between membrane composition and immune evasion, alternate sugar utilization, and drug tolerance in C. auris.

Extra-appendiceal mucinous neoplasms: A tumour with clinicopathologic similarities to low- and high-grade appendiceal counterpart.

AIMS: Appendiceal mucinous neoplasms feature neoplastic mucinous epithelium with pushing borders and densely fibrotic walls. We have identified five examples of analogous colorectal tumours. METHODS AND RESULTS: Slides, pathology reports, and clinical data were reviewed. Whole genome sequencing was performed in two cases. Three were women and the mean age was 70. Associated GI conditions included Crohn's disease [1], diverticulosis [2], and sarcoma of the terminal ileum [1]. Signs/symptoms included obstruction [2], nausea, vomiting, abdominal pain [1], and positive faecal immunohistochemical test [1]. Colonoscopic findings included narrowing [1], "fullness" [1], and caecal lesion concerning for GIST [1]. Tumours involved the rectosigmoid [2], sigmoid [1], transverse colon [1], and cecum [1] and ranged from 1.5 cm to 8.5 cm. All but one tumour arose in the setting of faecal stream abnormalities related to obstruction, diverticulosis, or bowel diversion. All cases showed columnar, variably mucinous epithelium associated with little-to-no lamina propria. All but one case showed fibrosis of the submucosa. Three cases had high-grade areas. Neoplastic glands and/or mucin dissected through the muscularis propria or subserosa in 3 examples. No extracolonic neoplastic cells/mucin, infiltrative invasion, or desmoplastic response were identified. Three patients with available follow-up [5.5-28 months] are alive. Whole genome sequencing identified pathogenic TP53 and ERBB2 variants, as well as ERBB2 copy number amplification in one high-grade example. CONCLUSIONS: Though these tumours share clinicopathologic characteristics with their appendiceal counterparts, our cohort is too small to draw solid conclusions. We propose the term "extra-appendiceal mucinous neoplasm [EAMN]" for these rare lesions.

Ensemble Detection of DNA Engineering Signatures.

Synthetic biology is creating genetically engineered organisms at an increasing rate for many potentially valuable applications, but this potential comes with the risk of misuse or accidental release. To begin to address this issue, we have developed a system called GUARDIAN that can automatically detect signatures of engineering in DNA sequencing data, and we have conducted a blinded test of this system using a curated Test and Evaluation (T&E) data set. GUARDIAN uses an ensemble approach based on the guiding principle that no single approach is likely to be able to detect engineering with perfect accuracy. Critically, ensembling enables GUARDIAN to detect sequence inserts in 13 target organisms with a high degree of specificity that requires no subject matter expert (SME) review.

Interfacial Assembly of Bacterial Microcompartment Shell Proteins in Aqueous Multiphase Systems.

Compartments are a fundamental feature of life, based variously on lipid membranes, protein shells, or biopolymer phase separation. Here, this combines self-assembling bacterial microcompartment (BMC) shell proteins and liquid-liquid phase separation (LLPS) to develop new forms of compartmentalization. It is found that BMC shell proteins assemble at the liquid-liquid interfaces between either 1) the dextran-rich droplets and PEG-rich continuous phase of a poly(ethyleneglycol)(PEG)/dextran aqueous two-phase system, or 2) the polypeptide-rich coacervate droplets and continuous dilute phase of a polylysine/polyaspartate complex coacervate system. Interfacial protein assemblies in the coacervate system are sensitive to the ratio of cationic to anionic polypeptides, consistent with electrostatically-driven assembly. In both systems, interfacial protein assembly competes with aggregation, with protein concentration and polycation availability impacting coating. These two LLPS systems are then combined to form a three-phase system wherein coacervate droplets are contained within dextran-rich phase droplets. Interfacial localization of BMC hexameric shell proteins is tunable in a three-phase system by changing the polyelectrolyte charge ratio. The tens-of-micron scale BMC shell protein-coated droplets introduced here can accommodate bioactive cargo such as enzymes or RNA and represent a new synthetic cell strategy for organizing biomimetic functionality.

Integration of Yeast Episomal/Integrative Plasmid Causes Genotypic and Phenotypic Diversity and Improved Sesquiterpene Production in Metabolically Engineered Saccharomyces cerevisiae.

The variability in phenotypic outcomes among biological replicates in engineered microbial factories presents a captivating mystery. Establishing the association between phenotypic variability and genetic drivers is important to solve this intricate puzzle. We applied a previously developed auxin-inducible depletion of hexokinase 2 as a metabolic engineering strategy for improved nerolidol production in Saccharomyces cerevisiae, and biological replicates exhibit a dichotomy in nerolidol production of either 3.5 or 2.5 g L-1 nerolidol. Harnessing Oxford Nanopore's long-read genomic sequencing, we reveal a potential genetic cause─the chromosome integration of a 2µ sequence-based yeast episomal plasmid, encoding the expression cassettes for nerolidol synthetic enzymes. This finding was reinforced through chromosome integration revalidation, engineering nerolidol and valencene production strains, and generating a diverse pool of yeast clones, each uniquely fingerprinted by gene copy numbers, plasmid integrations, other genomic rearrangements, protein expression levels, growth rate, and target product productivities. Τhe best clone in two strains produced 3.5 g L-1 nerolidol and ∼0.96 g L-1 valencene. Comparable genotypic and phenotypic variations were also generated through the integration of a yeast integrative plasmid lacking 2µ sequences. Our work shows that multiple factors, including plasmid integration status, subchromosomal location, gene copy number, sesquiterpene synthase expression level, and genome rearrangement, together play a complicated determinant role on the productivities of sesquiterpene product. Integration of yeast episomal/integrative plasmids may be used as a versatile method for increasing the diversity and optimizing the efficiency of yeast cell factories, thereby uncovering metabolic control mechanisms.

Engaging resident physicians in the design, implementation, and assessment of bedside interdisciplinary rounds.

Bedside interdisciplinary rounds (IDR) improve teamwork, communication, and collaborative culture in inpatient settings. Implementation of bedside IDR in academic settings depends on engagement from resident physicians; however, little is known about their knowledge and preferences related to bedside IDR. The goal of this program was to identify medical resident perceptions about bedside IDR and to engage resident physicians in the design, implementation, and assessment of bedside IDR in an academic setting. This is a pre-post mixed methods survey assessing resident physicians' perceptions surrounding a stakeholder-informed bedside IDR quality improvement project. Resident physicians in the University of Colorado Internal Medicine Residency Program (n = 77 pre-implementation survey responses from 179 eligible participants - response rate 43%) were recruited via e-mail to participate in surveys assessing perceptions surrounding the inclusion of interprofessional team members, timing, and preferred structure of bedside IDR. A bedside IDR structure was created based on input from resident and attending physicians, patients, nurses, care coordinators, pharmacists, social workers, and rehabilitation specialists. This rounding structure was implemented on acute care wards in June 2019 at a large academic regional VA hospital in Aurora, CO. Resident physicians were surveyed post implementation (n = 58 post-implementation responses from 141 eligible participants - response rate 41%) about interprofessional input, timing, and satisfaction with bedside IDR. The pre-implementation survey revealed several important resident needs during bedside IDR. Post-implementation survey results revealed high overall satisfaction with bedside IDR among residents, improved perceived efficiency of rounds, preserved quality of education, and value added by interprofessional input. Results also suggested areas for future improvement including timeliness of rounds and enhanced systems-based teaching. This project successfully engaged residents as stakeholders in system-level interprofessional change by incorporating their values and preferences into a bedside IDR framework.

Auditory Hair Cells and Spiral Ganglion Neurons Regenerate Synapses with Refined Release Properties In Vitro.

Ribbon synapses between inner hair cells (IHCs) and type I spiral ganglion neurons (SGNs) in the inner ear are damaged by noise trauma and with aging, causing 'synaptopathy 'and hearing loss. Co-cultures of neonatal denervated organs of Corti and newly introduced SGNs have been developed to find strategies for improving IHC synapse regeneration, but evidence of the physiological normality of regenerated synapses is missing. This study utilizes IHC optogenetic stimulation and SGN recordings, showing that newly formed IHC synapses are indeed functional, exhibiting glutamatergic excitatory postsynaptic currents. When older organs of Corti were plated, synaptic activity probed by deconvolution, showed more mature release properties, closer to the highly specialized mode of IHC synaptic transmission that is crucial for coding the sound signal. This newly developed functional assessment of regenerated IHC synapses provides a powerful tool for testing approaches to improve synapse regeneration.

Targeted control of supporting pathways in paclitaxel biosynthesis with CRISPR-guided methylation.

Introduction: Plant cell culture biomanufacturing is rapidly becoming an effective strategy for production of high-value plant natural products, such as therapeutic proteins and small molecules, vaccine adjuvants, and nutraceuticals. Many of these plant natural products are synthesized from diverse molecular building blocks sourced from different metabolic pathways. Even so, engineering approaches for increasing plant natural product biosynthesis have typically focused on the core biosynthetic pathway rather than the supporting pathways. Methods: Here, we use both CRISPR-guided DNA methylation and chemical inhibitors to control flux through the phenylpropanoid pathway in Taxus chinensis, which contributes a phenylalanine derivative to the biosynthesis of paclitaxel (Taxol), a potent anticancer drug. To inhibit PAL, the first committed step in phenylpropanoid biosynthesis, we knocked down expression of PAL in Taxus chinensis plant cell cultures using a CRISPR-guided plant DNA methyltransferase (NtDRM). For chemical inhibition of downstream steps in the pathway, we treated Taxus chinensis plant cell cultures with piperonylic acid and caffeic acid, which inhibit the second and third committed steps in phenylpropanoid biosynthesis: cinnamate 4-hydroxylase (C4H) and 4-coumaroyl-CoA ligase (4CL), respectively. Results: Knockdown of PAL through CRISPR-guided DNA methylation resulted in a profound 25-fold increase in paclitaxel accumulation. Further, through the synergistic action of both chemical inhibitors and precursor feeding of exogenous phenylalanine, we achieve a 3.5-fold increase in paclitaxel biosynthesis and a similar reduction in production of total flavonoids and phenolics. We also observed perturbations to both activity and expression of PAL, illustrating the complex transcriptional co-regulation of these first three pathway steps. Discussion: These results highlight the importance of controlling the metabolic flux of supporting pathways in natural product biosynthesis and pioneers CRISPR-guided methylation as an effective method for metabolic engineering in plant cell cultures. Ultimately, this work demonstrates a powerful method for rewiring plant cell culture systems into next-generation chassis for production of societally valuable compounds.

Isolation and sequencing of the spoilage yeast Kregervanrija delftensis.

New sequencing workflows can enable the genomics of microbes isolated from craft beverages. Here, we use hybrid, short, and long-read sequencing to assemble the genome of a yeast isolated from cider, Kregervanrija delftensis NCC-J. The Kregervanrija genus has few genomes available; thus, this contributes to yeast genomics.

Draft genome of the Ogataea polymorpha type strain CBS 4732.

The methylotrophic yeast Ogataea polymorpha is of significant biotechnological interest, particularly in high-temperature fermentations and for recombinant protein production. Here, we present a high-quality genome assembly for the O. polymorpha type strain CBS 4732.

Do Intrathecal Opioids Improve Surgical Outcomes After Coronary Artery Bypass Grafting? A Systematic Review and Analysis.

BACKGROUND: Intrathecal opioids have long been used as analgesia for intractable cancer pain or as part of spinal anesthesia during obstetric operations. More recently, they have been used preoperatively as a pain management adjuvant for open cardiac and thoracic procedures. OBJECTIVE: This study aims to analyze the impact of administering intrathecal opioids before cardiac and thoracic surgeries on postoperative pain and mechanical ventilation. STUDY DESIGN: Systematic review and meta-analysis. SETTING: University, School of Medicine, and several university-affiliated hospitals. METHODS: Five outcomes were studied, including the primary outcome of time to extubation, secondary outcomes of analgesia requirements at 24 and 48 hours, resting pain scores at 1 and 24 hours post-extubation, ICU length of stay in hours, and hospital length of stay in days. A search of multiple databases provided 28 studies reporting 4,000 total patients. Outcomes were measured using continuous mean difference with a 95% confidence interval, and the studies were examined for heterogeneity and sensitivity analysis. RESULTS: The primary outcome analysis suggested that time to extubation was 42 minutes shorter in the intrathecal opioid group (ranging from 82 to 1 minute, P = 0.04). There was also a decrease in postoperative analgesia requirements at both 24 hours (mean difference (MD) = -8.95 mg morphine equivalent doses (MED) [-9.4, -8.5], P < 0.001) and 48 hours (MD = -17.7 mg MED [-23.1, -12.4], P < 0.001) with I2 of 94% and 85% respectively, an improvement of pain scores at both 1 hour (MD = -2.24 [-3.16, -1.32], P < 0.001) and 24-hours (MD = -1.64 [-2.48, -0.80], P =< 0.001) I2 of 94% and 85%, no change in both ICU length of stay (MD = -0.27 hours [-0.55, 0.01], P = 0.06) I2 = 77% and hospital length of stay (MD = -0.30 days [-0.66, 0.06], P = 0.11) I2 = 32%. LIMITATIONS: The major limitation of this meta-analysis was the inconsistent dosages of intrathecal opioids utilized. Some used the same dose for each patient, while other studies used weight-based doses. The differences in the outcomes observed may then be a result of the different amounts of opioids administered rather than the technique itself. Another limitation was the inconsistent timing of reports for pain scores and postoperative analgesic requirements. Further studies were analyzed at the 2 time periods for both secondary outcomes, making it difficult to attribute the 2 effects solely to the intervention. CONCLUSIONS: We conclude that preoperative injection of intrathecal opioids is significantly associated with decreased time to extubation, decreased postoperative analgesia requirement, and improved pain scores. In controlled conditions with adequate staff education, this method of analgesia may make it possible to extubate the patients after the surgery in the operating room and fast-track their discharge from the hospital.

Systematic Part Transfer by Extending a Modular Toolkit to Diverse Bacteria.

It is impractical to develop a new parts collection for every potential host organism. It is well-established that gene expression parts, like genes, are qualitatively transferable, but there is little quantitative information defining transferability. Here, we systematically quantified the behavior of a parts set across multiple hosts. To do this, we developed a broad host range (BHR) plasmid system compatible with the large, modular CIDAR parts collection for E. coli, which we named openCIDAR. This enabled testing of a library of DNA constructs across the Pseudomonadota─Escherichia coli, Pseudomonas putida, Cupriavidus necator, and Komagataeibacter nataicola. Part performance was evaluated with a standardized characterization procedure that quantified expression in terms of molecules of equivalent fluorescein (MEFL), an objective unit of measure. The results showed that the CIDAR parts enable graded gene expression across all organisms─meaning that the same parts can be used to program E. coli, P. putida, C. necator, and K. nataicola. Most parts had a similar expression trend across hosts, although each organism had a different average gene expression level. The variability is enough that to achieve the same MEFL in a different organism, a lookup table is required to translate a design from one host to another. To identify truly divergent parts, we applied linear regression to a combinatorial set of promoters and ribosome binding sites, finding that the promoter J23100 behaves very differently in K. nataicola than in the other hosts. Thus, it is now possible to evaluate any CIDAR compatible part in three other hosts of interest, and the diversity of these hosts implies that the collection will also be compatible with many other Proteobacteria (Pseudomonadota). Furthermore, this work defines an approach to generalize modular synthetic biology parts sets beyond a single host, implying that only a few parts sets may be needed to span the tree of life. This will accelerate current efforts to engineer diverse species for environmental, biotechnological, and health applications.

Hepatitis B e Antigen-Negative Single Hepatocyte Analysis Shows Transcriptional Silencing and Slow Decay of Infected Cells With Treatment.

BACKGROUND: Nucleos(t)ide analogues (NUCs) rarely cure chronic hepatitis B (CHB) because they do not eliminate covalently closed circular deoxyribonucleic acid, the stable replication template. In hepatitis B e antigen (HBeAg)-positive CHB during NUCs, HBV-infected cells decline slowly and are transcriptionally silenced. Whether these occur in HBeAg-negative CHB is unknown. METHODS: Using paired liver biopsies separated by 2.7-3.7 years in 4 males with HIV and HBeAg-negative CHB at both biopsies and 1 male with HIV who underwent HBeAg seroconversion between biopsies, we quantified amounts of viral nucleic acids in hundreds of individual hepatocytes. RESULTS: In the 4 persistently HBeAg-negative participants, HBV-infected hepatocytes ranged from 6.2% to 17.7% (biopsy 1) and significantly declined in 3 of 4 by biopsy 2. In the HBeAg seroconverter, the proportion was 97.4% (biopsy 1) and declined to 81.9% at biopsy 2 (P < .05). We extrapolated that HBV eradication with NUCs would take >100 years. At biopsy 1 in the persistently HBeAg-negative participants, 23%-56.8% of infected hepatocytes were transcriptionally inactive-higher than we observed in HBeAg-positive CHB-and significantly declined in 1 of 4 at biopsy 2. CONCLUSIONS: In HBeAg-negative CHB on NUCs, the negligible decline in infected hepatocytes is similar to HBeAg-positive CHB, supporting the need for more potent therapeutics to achieve functional cure.

Genetic basis for probiotic yeast phenotypes revealed by nanopore sequencing.

Probiotic yeasts are emerging as preventative and therapeutic solutions for disease. Often ingested via cultured foods and beverages, they can survive the harsh conditions of the gastrointestinal tract and adhere to it, where they provide nutrients and inhibit pathogens like Candida albicans. Yet, little is known of the genomic determinants of these beneficial traits. To this end, we have sequenced 2 food-derived probiotic yeast isolates that mitigate fungal infections. We find that the first strain, KTP, is a strain of Saccharomyces cerevisiae within a small clade that lacks any apparent ancestry from common European/wine S. cerevisiae strains. Significantly, we show that S. cerevisiae KTP genes involved in general stress, pH tolerance, and adherence are markedly different from S. cerevisiae S288C but are similar to the commercial probiotic yeast species S. boulardii. This suggests that even though S. cerevisiae KTP and S. boulardii are from different clades, they may achieve probiotic effect through similar genetic mechanisms. We find that the second strain, ApC, is a strain of Issatchenkia occidentalis, one of the few of this family of yeasts to be sequenced. Because of the dissimilarity of its genome structure and gene organization, we infer that I. occidentalis ApC likely achieves a probiotic effect through a different mechanism than the Saccharomyces strains. Therefore, this work establishes a strong genetic link among probiotic Saccharomycetes, advances the genomics of Issatchenkia yeasts, and indicates that probiotic activity is not monophyletic and complimentary mixtures of probiotics could enhance health benefits beyond a single species.

Structural properties of optically clear bacterial cellulose produced by Komagataeibacter hansenii using arabitol.

Bacterial cellulose (BC) exhibits beneficial properties for use in biomedical applications but is limited by its lack of tunable transparency capabilities. To overcome this deficiency, a novel method to synthesize transparent BC materials using an alternative carbon source, namely arabitol, was developed. Characterization of the BC pellicles was performed for yield, transparency, surface morphology, and molecular assembly. Transparent BC was produced using mixtures of glucose and arabitol. Zero percent arabitol pellicles exhibited 25% light transmittance, which increased with increasing arabitol concentration through to 75% light transmittance. While transparency increased, overall BC yield was maintained indicating that the altered transparency may be induced on a micro-scale rather than a macro-scale. Significant differences in fiber diameter and the presence of aromatic signatures were observed. Overall, this research outlines methods for producing BC with tunable optical transparency, while also bringing new insight to insoluble components of exopolymers produced by Komagataeibacter hansenii.

Mortality Risk of Patients Treated in Dialysis Facilities with Payment Reductions under ESRD Quality Incentive Program.

BACKGROUND: The Centers for Medicare & Medicaid Services End-Stage Renal Disease Quality Incentive Program (ESRD QIP) measures quality of care delivered by dialysis facilities and imposes Medicare payment reductions for quality lapses. We assessed the association between payment reductions and patient mortality, a quality indicator not included in the ESRD QIP measure set. METHODS: Association between mortality and ESRD QIP facility payment reduction based on the year of performance was expressed as the unadjusted rate and patient case-mix-adjusted hazard ratio. We also measured association between mortality and 1-year changes in payment reductions. Retrospective patient cohorts were defined by their treating dialysis facility on the first day of each year (2010-2018). RESULTS: Facility performance resulted in payment reductions for 5%-42% of dialysis facilities over the 9 study years. Patients experienced progressively higher mortality at each payment reduction level. Across all years, unadjusted mortality was 17.3, 18.1, 18.9, 20.3, and 23.9 deaths per 100 patient-years for patients in facilities that received 0%, 0.5%, 1%, 1.5%, and 2% payment reductions, respectively. The adjusted hazard ratio showed a similar stepwise pattern by the level of payment reduction: 1.0 (reference), 1.08 (95% confidence interval [CI], 1.07 to 1.09), 1.15 (95% CI, 1.13 to 1.16), 1.19 (95% CI, 1.16 to 1.21), and 1.34 (95% CI, 1.29 to 1.39). Strength of the association increased from 2010 to 2016. Patients treated in facilities that improved over 1 year generally experienced lower mortality; patients in facilities that performed worse on ESRD QIP measures generally experienced higher mortality. CONCLUSIONS: Patient mortality was associated with ESRD QIP facility payment reductions in dose-response and temporal patterns.

Hemoglobin and Clinical Outcomes in Hemodialysis: An Analysis of US Medicare Data From 2018 to 2020.

Rationale & Objective: Anemia management in patients treated with maintenance dialysis remains a challenge. We sought to update information in this area by evaluating the association between hemoglobin and various outcome and utilization measures using data-rich Medicare sources. Study Design: Observational cohort study using data from the Consolidated Renal Operations in a Web-enabled Network and Medicare claims. Setting & Participants: We studied 371,250 prevalent patients treated with hemodialysis, covering 3,326,072 patient-months in 2019. Exposure: Monthly patient hemoglobin concentrations. Outcomes: We examined several outcomes, including mortality, all-cause hospitalization, cause-specific hospitalization, and emergency department utilization in the month following the exposure measurement. Analytical Approach: For each monthly observation period, we calculated unadjusted and adjusted (for demographics and comorbid condition) hazard ratios using Cox regression. Results: The hemoglobin concentration was <10.5 g/dL for 40% of observations. We found an inverse association between mortality and hemoglobin measured over a range from <9 g/dL (HR, 2.53; 95% CI, 2.45-2.61; P < 0.0001, reference = 10.5-11 g/dL) to 11-11.5 g/dL (HR, 0.92; 95% CI, 0.89-0.96; P < 0.0001). Mortality risk started to increase at hemoglobin levels >11.5 g/dL. All-cause hospitalization, cause-specific hospitalization (including cardiovascular, infection, and several subcategories including coronavirus disease 2019 hospitalization), and emergency department utilization were inversely associated with hemoglobin concentration, with risk reduction stabilizing at hemoglobin levels of approximately 11.5-12 g/dL and higher. Limitations: As with prior observational studies, the observed associations are not necessarily causal. Conclusions: In a large US hemodialysis population, there were better clinical outcomes at higher hemoglobin concentrations over short exposure and follow-up periods, consistent with other observational studies that generally used longer exposure and follow-up times. Mortality risk increased at hemoglobin concentrations >11.5 g/dL, consistent with findings from erythropoiesis-stimulating agent clinical trials. The apparently beneficial short-term effects associated with higher hemoglobin concentrations suggest that hemoglobin measurements capture unmeasured elements of patient risk.

Peritoneal Dialysis-Associated Peritonitis Trends Using Medicare Claims Data, 2013-2017.

RATIONALE & OBJECTIVE: The occurrence and consequences of peritoneal dialysis (PD)-associated peritonitis limit its use in populations with kidney failure. Studies of large clinical populations may enhance our understanding of peritonitis. To facilitate these studies we developed an approach to measuring peritonitis rates using Medicare claims data to characterize peritonitis trends and identify its clinical risk factors. STUDY DESIGN: Retrospective cohort study of PD-associated peritonitis. SETTING & PARTICIPANTS: US Renal Data System standard analysis files were used for claims, eligibility, modality, and demographic information. The sample consisted of patients receiving PD treated at some time between 2013 and 2017 who were covered by Medicare fee-for-service (FFS) insurance with paid claims for dialysis or hospital services. EXPOSURES/PREDICTORS: Peritonitis risk was characterized by year, age, sex, race, ethnicity, vintage of kidney replacement therapy, cause of kidney failure, and prior peritonitis episodes. OUTCOME: The major outcome was peritonitis, identified using ICD-9 and ICD-10 diagnosis codes. Closely spaced peritonitis claims (30 days) were aggregated into 1 peritonitis episode. ANALYTICAL APPROACH: Patient-level risk factors for peritonitis were modeled using Poisson regression. RESULTS: We identified 70,271 peritonitis episodes from 396,289 peritonitis claims. Although various codes were used to record an episode of peritonitis, none was used predominantly. Peritonitis episodes were often identified by multiple aggregated claims, with the mean and median claims per episode being 5.6 and 2, respectively. We found 40% of episodes were exclusively outpatient, 9% exclusively inpatient, and 16% were exclusively based on codes that do not clearly distinguish peritonitis from catheter infections/inflammation ("catheter codes"). The overall peritonitis rate was 0.54 episodes per patient-year (EPPY). The rate was 0.45 EPPY after excluding catheter codes and 0.35 EPPY when limited to episodes that only included claims from nephrologists or dialysis providers. The peritonitis rate declined by 5%/year and varied by patient factors including age (lower rates at higher ages), race (Black > White>Asian), and prior peritonitis episodes (higher rate with each prior episode). LIMITATIONS: Coding heterogeneity indicates a lack of standardization. Episodes based exclusively on catheter codes could represent false positives. Peritonitis episodes were not validated against symptoms or microbiologic data. CONCLUSIONS: PD-associated peritonitis rates decline over time and were lower among older patients. A claims-based approach offers a promising framework for the study of PD-associated peritonitis.

Hemostatic Efficacy and Safety of 4-Factor Prothrombin Complex Concentrate in Doac-Associated Intracranial Hemorrhage.

Background: Factor Xa (FXa) inhibitor use has increased over the last decade and though associated rates of major bleeding are lower compared to warfarin, outcomes from intracranial hemorrhage (ICH) are still significant. Targeted FXa inhibitor reversal agent became available in 2018, however use of 4-factor prothrombin complex concentrate (4F-PCC) for FXa inhibitor-associated ICH continues at many institutions. Objective: Evaluate the safety and hemostatic efficacy of 4F-PCC for FXa inhibitor-associated ICH. Methods: Single-center, retrospective study of patients who received 4F-PCC for FXa inhibitor-associated ICH. The primary efficacy endpoint was hemostasis and thrombosis was the main safety endpoint. Secondary endpoints included in-hospital mortality and discharge disposition. Results: 76 patients on apixaban or rivaroxaban were included. Good or excellent hemostasis was achieved in 80.3% of patients. Five patients experienced a thrombotic event. Favorable discharge disposition and lower in-hospital mortality was more likely in patients who achieved excellent hemostasis. Conclusion: 4F-PCC is safe and effective for FXa inhibitor associated ICH.