Tocilizumab Associated With Survival in Patients Hospitalized for COVID-19 Acute Respiratory Distress Syndrome and Low Urine Output.

BACKGROUND: Acute respiratory distress syndrome (ARDS) with oliguria is associated with increased mortality. Interleukin-6 (IL-6) plays an integral role in the pathophysiology of both disease processes. Patients who experience severe COVID-19 have demonstrated higher IL-6 levels compared to baseline, and use of tocilizumab has demonstrated efficacy in such cohorts. We set out to investigate the relationship between tocilizumab use, COVID-19 ARDS, low urine output, and mortality. METHODS: Retrospective cohort review of adult patients aged ≥ 18 years with COVID-19 and moderate or severe ARDS, admitted to the intensive care unit (ICU) of a tertiary referral center in metropolitan Detroit. Patients were analyzed based on presence of oliguria (defined as ≤ 0.7 mL/kg/h) on the day of intubation and exposure to tocilizumab while inpatient. The primary outcome was inpatient mortality. RESULTS: One hundred and twenty-eight patients were analyzed, 103 (80%) with low urine output, of whom 30 (29%) received tocilizumab. In patients with low urine output, risk factors associated with mortality on univariate analysis included Black race (P = .028), lower static compliance (P = .015), and tocilizumab administration (P = .002). Tocilizumab (odds ratio 0.245, 95% confidence interval 0.079-0.764, P = .015) was the only risk factor independently associated with survival on multivariate logistic regression analysis. CONCLUSION: In this retrospective cohort review of patients hospitalized with COVID-19 and moderate or severe ARDS, tocilizumab administration was independently associated with survival in patients with low urine output ≤ 0.7 mL/kg/h on the day of intubation. Prospective studies are needed to investigate the impact of urine output on efficacy of interleukin-targeted therapies in the management of ARDS.

A Case of Acute Liver Failure Due to Artemisinin-Derived Herbal Supplements.

A 49-year-old female presented with malaise, nausea, vomiting, and discolored urine. She was found to have an acute liver failure with labs significant for aspartate aminotransferase (AST) of 2164, alanine aminotransferase (ALT) of 2425, alkaline phosphatase (ALP) of 106, total bilirubin of 3.6, and lactate dehydrogenase (LDH) of 2269. The international normalized ratio (INR) was also elevated at 1.9. All workup for acute liver failure was negative and it was found that she had started taking a new supplement called "Gut Health", which contained artemisinin, for weight loss and menopausal symptoms. After discontinuing the supplements and symptomatically treating her for acute liver failure, her transaminitis resolved.

Oliguria on the Day of Intubation Is Associated With Mortality in Patients With Acute Respiratory Distress Syndrome.

To investigate the relationship between oliguric acute kidney injury (AKI) and mortality in patients with acute respiratory distress syndrome (ARDS). DESIGN: Retrospective cohort study. SETTING: This investigation took place at a single-center, tertiary referral multidisciplinary comprehensive healthcare hospital in metropolitan Detroit, Michigan. PATIENTS: Adult patients 18 years old or older hospitalized in the ICU and diagnosed with ARDS on mechanical ventilation. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Three hundred eight patients were included in the final analysis. Risk factors associated with mortality included advanced age (p < 0.001), increased body mass index (p = 0.008), and a history of chronic kidney disease (p = 0.023). Presence of AKI by day 1 of intubation, with elevated creatinine (p = 0.003) and oliguria (p < 0.001), was significantly associated with mortality. On multivariate analysis, advanced age (relative risk [RR], 1.02), urine output on the day of intubation (RR, 0.388), bicarbonate level (RR, 0.948), and Sequential Organ Failure Assessment severity score (RR, 1.09) were independently associated with mortality. A receiver operating characteristic curve identified a threshold urine output on the day of intubation of 0.7 mL/kg/hr (area under the curve, 0.75; p < 0.001) as most closely associated with inpatient mortality (i.e., urine output < 0.7 mL/kg/hr is associated with mortality). CONCLUSIONS: For patients with ARDS, oliguria on the day of intubation was independently associated with increased mortality. Urine output of less than 0.7 mL/kg/hr predicted 80% of inpatient deaths. These findings herald an augmented understanding of the role of urine output in medical decision-making and prognostication.

Saccharomyces cerevisiae lysophospholipid acyltransferase, Lpt1, requires Asp146 and Glu297 for catalysis.

The esterification of lysophospholipids contributes to phospholipid synthesis, remodeling, and scavenging. Acyl-CoA-dependent lysophospholipid acyltransferase activity with broad substrate use is mediated by Saccharomyces cerevisiae Lpt1p. We sought to identify Lpt1p active site amino acids besides the histidine conserved among homologs and repeatedly found to be required for catalysis. In vitro Lpt1p assays with amino acid modifying agents implicated aspartate, glutamate, and lysine as active site residues. Threonine and tyrosine were not ruled out. Aligning the primary structures of functionally characterized LPT1 homologs from fungi, plants, and animals identified 11 conserved aspartate, glutamate, lysine, threonine, and tyrosine residues. Site-directed mutagenesis of the respective codons showed that changing D146 and E297 abolished activity without abolishing protein expression. The mechanism of Lpt1p was further analyzed using monounsaturated acyl-CoA species with different double bond positions. Delta 6 species showed the highest catalytic efficiency. We propose that D146 and E297 act in conjunction with H382 as nucleophiles that attack the hydroxyl group in lysophospholipids in a general acid/base mechanism. This sequential mechanism provides a precedent for other members of the membrane bound O-acyltransferase family. Also, Lpt1p optimally orients acyl-CoA substrates with 7.5 Å between a double bond and the thioester bond.