Proteomic Pathway Analysis of Monocyte-Derived Exosomes during Surgical Sepsis Identifies Immunoregulatory Functions

Background: Patients with sepsis exhibit significant long-term immunosuppressive sequelae. Monocyte dysfunction is a hallmark of this damage. Circulating exosomes are an important mediator of the systemic signaling events that occur during the septic response; thus, we sought to characterize the contribution of circulating exosomes to the inflammatory process induced during sepsis Methods: Monocyte-derived exosomes were isolated from cultured monocytes from healthy adult donors via stimulation with lipopolysaccharide (LPS) or phosphate-buffered saline (PBS). The proteome was determined by capillary-liquid chromatography-nanospray tandem mass spectrometry (capillary-LC/NT/MS). Using pathway analysis, proteomic networks of exosomes derived from LPS-stimulated monocytes were compared with those isolated from patients with surgical sepsis. Naïve monocytes were then treated with these exosomes and stimulated with LPS to determine the effects on recipient-cell immune function. Results: Proteomic analysis demonstrated 18 differentially expressed proteins (17 down-regulated, one up-regulated) in sepsis-derived exosomes, with 15 differentially expressed proteins (14 down-regulated, one up-regulated) in the LPS-stimulated exosomes. Functional enrichment analysis demonstrated several down-regulated processes, including localization, biogenesis, and metabolic and cellular processes in addition to immune system processes. In LPS-stimulated macrophages, similar down-regulated processes were seen, including metabolic and cellular processes, as well as the response to stimulus. Cells treated with sepsis-derived exosomes or exosomes from LPS-stimulated monocytes demonstrated significant reductions in tumor necrosis factor (TNF)-α generation in response to LPS stimulation. Conclusions: Proteomic analysis of sepsis-derived exosomes and LPS-stimulated, macrophage-derived exosomes exhibited down-regulation of several important protein networks, including the immune response. In addition, human monocytes treated with exosomes from patients with sepsis or LPS-stimulated monocytes demonstrated significant reductions in TNF-α generation in response to LPS stimulation. These data suggest the contribution of circulating exosomes to systemic signaling and immunomodulation during sepsis

Patient Factors Associated With Appendectomy Within 30 Days of Initiating Antibiotic Treatment for Appendicitis

Importance: Use of antibiotics for the treatment of appendicitis is safe and has been found to be noninferior to appendectomy based on self-reported health status at 30 days. Identifying patient characteristics associated with a greater likelihood of appendectomy within 30 days in those who initiate antibiotics could support more individualized decision-making. Objective: To assess patient factors associated with undergoing appendectomy within 30 days of initiating antibiotics for appendicitis. Design, Setting, and Participants: In this cohort study using data from the Comparison of Outcomes of Antibiotic Drugs and Appendectomy (CODA) randomized clinical trial, characteristics among patients who initiated antibiotics were compared between those who did and did not undergo appendectomy within 30 days. The study was conducted at 25 US medical centers; participants were enrolled between May 3, 2016, and February 5, 2020. A total of 1552 participants with acute appendicitis were randomized to antibiotics (776 participants) or appendectomy (776 participants). Data were analyzed from September 2020 to July 2021. Exposures: Appendectomy vs antibiotics. Main Outcomes and Measures: Conditional logistic regression models were fit to estimate associations between specific patient factors and the odds of undergoing appendectomy within 30 days after initiating antibiotics. A sensitivity analysis was performed excluding participants who underwent appendectomy within 30 days for nonclinical reasons. Results: Of 776 participants initiating antibiotics (mean [SD] age, 38.3 [13.4] years; 286 [37%] women and 490 [63%] men), 735 participants had 30-day outcomes, including 154 participants (21%) who underwent appendectomy within 30 days. After adjustment for other factors, female sex (odds ratio [OR], 1.53; 95% CI, 1.01-2.31), radiographic finding of wider appendiceal diameter (OR per 1-mm increase, 1.09; 95% CI, 1.00-1.18), and presence of appendicolith (OR, 1.99; 95% CI, 1.28-3.10) were associated with increased odds of undergoing appendectomy within 30 days. Characteristics that are often associated with increased risk of complications (eg, advanced age, comorbid conditions) and those clinicians often use to describe appendicitis severity (eg, fever: OR, 1.28; 95% CI, 0.82-1.98) were not associated with odds of 30-day appendectomy. The sensitivity analysis limited to appendectomies performed for clinical reasons provided similar results regarding appendicolith (adjusted OR, 2.41; 95% CI, 1.49-3.91). Conclusions and Relevance: This cohort study found that presence of an appendicolith was associated with a nearly 2-fold increased risk of undergoing appendectomy within 30 days of initiating antibiotics. Clinical characteristics often used to describe severity of appendicitis were not associated with odds of 30-day appendectomy. This information may help guide more individualized decision-making for people with appendicitis

Self-selection vs Randomized Assignment of Treatment for Appendicitis.

Importance: For adults with appendicitis, several randomized clinical trials have demonstrated that antibiotics are an effective alternative to appendectomy. However, it remains unknown how the characteristics of patients in such trials compare with those of patients who select their treatment and whether outcomes differ. Objective: To compare participants in the Comparison of Outcomes of Antibiotic Drugs and Appendectomy (CODA) randomized clinical trial (RCT) with a parallel cohort study of participants who declined randomization and self-selected treatment. Design, Setting, and Participants: The CODA trial was conducted in 25 US medical centers. Participants were enrolled between May 3, 2016, and February 5, 2020; all participants were eligible for at least 1 year of follow-up, with all follow-up ending in 2021. The randomized cohort included 1094 adults with appendicitis; the self-selection cohort included patients who declined participation in the randomized group, of whom 253 selected appendectomy and 257 selected antibiotics. In this secondary analysis, characteristics and outcomes in both self-selection and randomized cohorts are described with an exploratory analysis of cohort status and receipt of appendectomy. Interventions: Appendectomy vs antibiotics. Main Outcomes and Measures: Characteristics among participants randomized to either appendectomy or antibiotics were compared with those of participants who selected their own treatment. Results: Clinical characteristics were similar across the self-selection cohort (510 patients; mean age, 35.8 years [95% CI, 34.5-37.1]; 218 female [43%; 95% CI, 39%-47%]) and the randomized group (1094 patients; mean age, 38.2 years [95% CI, 37.4-39.0]; 386 female [35%; 95% CI, 33%-38%]). Compared with the randomized group, those in the self-selection cohort were less often Spanish speaking (n = 99 [19%; 95% CI, 16%-23%] vs n = 336 [31%; 95% CI, 28%-34%]), reported more formal education (some college or more, n = 355 [72%; 95% CI, 68%-76%] vs n = 674 [63%; 95% CI, 60%-65%]), and more often had commercial insurance (n = 259 [53%; 95% CI, 48%-57%] vs n = 486 [45%; 95% CI, 42%-48%]). Most outcomes were similar between the self-selection and randomized cohorts. The number of patients undergoing appendectomy by 30 days was 38 (15.3%; 95% CI, 10.7%-19.7%) among those selecting antibiotics and 155 (19.2%; 95% CI, 15.9%-22.5%) in those who were randomized to antibiotics (difference, 3.9%; 95% CI, -1.7% to 9.5%). Differences in the rate of appendectomy were primarily observed in the non-appendicolith subgroup. Conclusions and Relevance: This secondary analysis of the CODA RCT found substantially similar outcomes across the randomized and self-selection cohorts, suggesting that the randomized trial results are generalizable to the community at large. Trial Registration: ClinicalTrials.gov Identifier: NCT02800785

Analysis of Outcomes Associated With Outpatient Management of Nonoperatively Treated Patients With Appendicitis.

Importance: In the Comparison of Outcomes of Antibiotic Drugs and Appendectomy (CODA) trial, which found antibiotics to be noninferior, approximately half of participants randomized to receive antibiotics had outpatient management with hospital discharge within 24 hours. If outpatient management is safe, it could increase convenience and decrease health care use and costs. Objective: To assess the use and safety of outpatient management of acute appendicitis. Design, Setting, and Participants: This cohort study, which is a secondary analysis of the CODA trial, included 776 adults with imaging-confirmed appendicitis who received antibiotics at 25 US hospitals from May 1, 2016, to February 28, 2020. Exposures: Participants randomized to antibiotics (intravenous then oral) could be discharged from the emergency department based on clinician judgment and prespecified criteria (hemodynamically stable, afebrile, oral intake tolerated, pain controlled, and follow-up confirmed). Outpatient management and hospitalization were defined as discharge within or after 24 hours, respectively. Main Outcomes and Measures: Outcomes compared among patients receiving outpatient vs inpatient care included serious adverse events (SAEs), appendectomies, health care encounters, satisfaction, missed workdays at 7 days, and EuroQol 5-dimension (EQ-5D) score at 30 days. In addition, appendectomy incidence among outpatients and inpatients, unadjusted and adjusted for illness severity, was compared. Results: Among 776 antibiotic-randomized participants, 42 (5.4%) underwent appendectomy within 24 hours and 8 (1.0%) did not receive their first antibiotic dose within 24 hours, leaving 726 (93.6%) comprising the study population (median age, 36 years; range, 18-86 years; 462 [63.6%] male; 437 [60.2%] White). Of these participants, 335 (46.1%; site range, 0-89.2%) were discharged within 24 hours, and 391 (53.9%) were discharged after 24 hours. Over 7 days, SAEs occurred in 0.9 (95% CI, 0.2-2.6) per 100 outpatients and 1.3 (95% CI, 0.4-2.9) per 100 inpatients; in the appendicolith subgroup, SAEs occurred in 2.3 (95% CI, 0.3-8.2) per 100 outpatients vs 2.8 (95% CI, 0.6-7.9) per 100 inpatients. During this period, appendectomy occurred in 9.9% (95% CI, 6.9%-13.7%) of outpatients and 14.1% (95% CI, 10.8%-18.0%) of inpatients; adjusted analysis demonstrated a similar difference in incidence (-4.0 percentage points; 95% CI, -8.7 to 0.6). At 30 days, appendectomies occurred in 12.6% (95% CI, 9.1%-16.7%) of outpatients and 19.0% (95% CI, 15.1%-23.4%) of inpatients. Outpatients missed fewer workdays (2.6 days; 95% CI, 2.3-2.9 days) than did inpatients (3.8 days; 95% CI, 3.4-4.3 days) and had similar frequency of return health care visits and high satisfaction and EQ-5D scores. Conclusions and Relevance: These findings support that outpatient antibiotic management is safe for selected adults with acute appendicitis, with no greater risk of complications or appendectomy than hospital care, and should be included in shared decision-making discussions of patient preferences for outcomes associated with nonoperative and operative care. Trial Registration: ClinicalTrials.gov Identifier: NCT02800785

Perception of Treatment Success and Impact on Function with Antibiotics or Appendectomy for Appendicitis

ObjectiveTo compare secondary patient reported outcomes of perceptions of treatment success and function for patients treated for appendicitis with appendectomy vs. antibiotics at 30 days.Summary background dataThe Comparison of Outcomes of antibiotic Drugs and Appendectomy trial found antibiotics noninferior to appendectomy based on 30-day health status. To address questions about outcomes among participants with lower socioeconomic status, we explored the relationship of sociodemographic and clinical factors and outcomes.MethodsWe focused on 4 patient reported outcomes at 30 days: high decisional regret, dissatisfaction with treatment, problems performing usual activities, and missing >10 days of work. The randomized (RCT) and observational cohorts were pooled for exploration of baseline factors. The RCT cohort alone was used for comparison of treatments. Logistic regression was used to assess associations.ResultsThe pooled cohort contained 2062 participants; 1552 from the RCT. Overall, regret and dissatisfaction were low whereas problems with usual activities and prolonged missed work occurred more frequently. In the RCT, those assigned to antibiotics had more regret (Odd ratios (OR) 2.97, 95% Confidence intervals (CI) 2.05-4.31) and dissatisfaction (OR 1.98, 95%CI 1.25-3.12), and reported less missed work (OR 0.39, 95%CI 0.27-0.56). Factors associated with function outcomes included sociodemographic and clinical variables for both treatment arms. Fewer factors were associated with dissatisfaction and regret.ConclusionsOverall, participants reported high satisfaction, low regret, and were frequently able to resume usual activities and return to work. When comparing treatments for appendicitis, no single measure defines success or failure for all people. The reported data may inform discussions regarding the most appropriate treatment for individuals.Trial registrationClinicaltrials.gov Identifier: NCT02800785