Risk Of Bacterial Infections Research Articles

Effect of minor gallium addition on corrosion, passivity, and antibacterial behaviour of novel β-type Ti–Nb alloys

Metastable Ti–Nb alloys are promising bone-implant materials due to improved mechanical biofunctionality and biocompatibility. To overcome increasing bacterial infection risk, alloying with antibacterial elements is a promising strategy. This study investigates the effect of minor gallium (Ga) additions (4, 8 wt% Ga) to as-cast and solution-treated β-type Ti–45Nb-based alloy (96(Ti–45Nb)-4Ga, 92(Ti–45Nb)-8Ga (wt.%)) on corrosion and passive film properties, as well as cytocompatibility and antibacterial activity. The electrochemical properties were evaluated by potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and Mott-Schottky analyses in phosphate-buffered saline (PBS). X-ray photoelectron spectroscopy (XPS) was performed to analyze the chemical composition of passive films. Early adhesion and viability of macrophages and Staphylococcus aureus were assessed by nucleocounting and colony-forming unit counting, respectively. The results showed that high corrosion resistance and passive film properties of Ti–45Nb are retained and even slightly improved with Ga. EIS results revealed that Ga addition improves the passive film resistance. XPS measurements of 92(Ti–45Nb)-8Ga show that the passive film contains Ti-, Nb- and Ga-based oxides, implying the formation of mixed (Ti–Nb-Ga) oxides. In addition, marginal Ga ion release rate was detected under free corrosion conditions. Therefore, it can be assumed that Ga species may contribute to passive film formation on Ga-containing alloys. The 92(Ti–45Nb)-8Ga elicited an antibacterial effect against S. aureus compared to cp-Ti at 4 h. Moreover, Ga-containing alloys showed good cytocompatibility with THP-1 macrophages at 24 h. In conclusion, it was demonstrated that Ga additions to Ti–45Nb are beneficial to corrosion resistance and showed promising initial host and bacterial interactions.

Infections occurring following IL6 blockade for the management of cytokine release syndrome in onco-hematology patients.

Cytokine release syndrome (CRS) is a common adverse event of CAR T cell or bispecific antibody (bsAb) therapy. Anti-IL6/IL6R drugs are used in the management of auto-immune diseases. Some reports showed increased risk of bacterial infection in this context. In onco-hematology, there are few data about the occurrence of infection after administration of an anti-IL6/IL6R for CRS. We retrospectively reviewed all consecutive patients treated in Gustave Roussy Cancer Campus between 2018 and 2021, who received anti-IL6/IL6R for CRS due to bsAb in phase I clinical trials or adoptive cellular therapy (ACT). We constituted a control group including all the patients treated in the same clinical trials or standard of care ACT, naïve of anti-IL6/IL6R. Fifty-two patients have been included. In the anti-IL6/IL6R group (n = 26), five patients developed a grade 2 to 5 infection within a month after anti-IL6/IL6R treatment, including two grade 5 infections. In the control group (n = 26), only one patient had a grade 3 infection. The two patients who had grade 5 infections were treated for diffuse large B cell lymphoma (DLBCL), one with bsAb and the other with CAR T cell. Fifty percent (3/6) of DLBCL patients who received an anti-IL6/IL6R presented an infection, one of which was a grade 5. In solid tumor patients treated with bsAb and anti-IL6/IL6R, only one patient (/9, 11%) developed a grade 2 viral infection. It seems that the use of anti-IL6/IL6R in CRS secondary to bsAb administration in solid tumors patients does not significantly increase the risk of infection, as opposed to DLBCL patients where secondary infection might be a concern.

Enhanced antibacterial and adhesive properties of chitosan/gelatin hydrogel containing berberine hydrochloride and prepolymerized gallic acid exhibiting aggregation‐induced emission

AbstractMedical devices and human implant materials carry a risk of bacterial infection. Biocompatible and adhesive antibacterial materials that prevent biofilm formation are commonly used to reduce the risk. Herein, a crosslinked chitosan/gelatin (CG) hybrid hydrogel with antibacterial and adhesive properties was developed by introducing berberine hydrochloride (BBR) and adhesive prepolymerized gallic acid (PGA) to the hydrogel. BBR self‐assembles into nanoparticles and imparts AIE function to hydrogels by intermolecular electrostatic interactions and π–π stacking. The hydrogel was used as a stable carrier for BBR. The antibiofilm performance against Escherichia coli and Staphylococcus aureus after light exposure increased from 20% and 30% (CG hydrogel) to 74% and 85% (CGBBRPGA hydrogel), respectively. When used as a photodynamic agent, the hybrid hydrogel exhibited enhanced antibacterial and antibiofilm capabilities against both Gram‐negative (E. coli) and Gram‐positive (S. aureus) bacteria. The CGBBRPGA hydrogel showed strong adhesion to the surfaces of pig skin (9.2 kPa), glass (7.6 kPa), steel sheet (5.8 kPa), and PEEK sheet (5.5 kPa). Furthermore, it exhibits cell adhesion and shows negligible cytotoxicity, which indicates its cytocompatibility. Consequently, the fabricated hybrid hydrogel offers potential applications in biomedicine, particularly in wound dressing and surface modification of medical implants.

Role of Magnesium in the Intensive Care Unit and Immunomodulation: A Literature Review.

Both the role and the importance of magnesium in clinical practice have grown considerably in recent years. Emerging evidence suggests an association between loss of magnesium homeostasis and increased mortality in the critical care setting. The underlying mechanism is still unclear, but an increasing number of in vivo and in vitro studies on magnesium's immunomodulating capabilities may shed some light on the matter. This review aims to discuss the evidence behind magnesium homeostasis in critically ill patients, and its link with intensive care unit mortality via a likely magnesium-induced dysregulation of the immune response. The underlying pathogenetic mechanisms, and their implications for clinical outcomes, are discussed. The available evidence strongly supports the crucial role of magnesium in immune system regulation and inflammatory response. The loss of magnesium homeostasis has been associated with an elevated risk of bacterial infections, exacerbated sepsis progression, and detrimental effects on the cardiac, respiratory, neurological, and renal systems, ultimately leading to increased mortality. However, magnesium supplementation has been shown to be beneficial in these conditions, highlighting the importance of maintaining adequate magnesium levels in the intensive care setting.

Case Report—Escherichia coli Pericarditis after Recent COVID-19 Pneumonia

Before the widespread use of antibiotics, purulent pericarditis was not uncommon and was predominantly a complication of bacterial pneumonia. We present a rare case of Escherichia coli (E. coli) purulent pericarditis without a clear source after a recent COVID-19 infection. Background: COVID-19 has been affecting millions of people worldwide since the outbreak in December 2019, and its involvement in multiple organ systems has been observed and studied. Multiple cardiac complications have been reported, most significantly the virus’ ability to induce acute coronary syndrome and myocarditis. Pericardial disease has also been reported but less frequently. COVID-19 infection is associated with a higher risk of secondary bacterial infection, but it is rare to see purulent pericarditis in the setting of a recent COVID-19 infection. Objective: Our case report depicts a patient who developed E. coli purulent pericarditis in the setting of a recent COVID-19 infection. It indicates a possible association between COVID-19 infection with dysregulation of the immune system.

Recurrent Scedosporium apiospermum Cutaneous Infection in a Patient with Rheumatoid Arthritis: The Potent Role of IL-6 Signaling Pathway Blockade: A Case-Based Review.

Rheumatoid arthritis (RA) patients deal with a higher risk of bacterial and fungal infections compared to the general population because of their dysregulated immune system as well as the immunosuppressive therapy they usually receive. Scedosporium spp. is a fungal pathogen responsible for cutaneous, lung, central nervous system, and eye infections, mostly in immunocompromised patients, leading to death in disseminated cases. We report the case of an 81-year-old woman with rheumatoid arthritis treated with steroids and an IL-6 inhibitor who was diagnosed with scedosporiosis of the upper limb. She was treated with voriconazole for one month, which was discontinued due to adverse events, and when scedosporiosis relapsed, she switched to itraconazole. We also reviewed the current literature on RA patients presenting with Scedosporium infections. Early and accurate diagnosis of scedosporiosis has therapeutic and prognostic implications, as traditionally this fungus is resistant to commonly used antifungals. Clinical alertness regarding uncommon infections, including fungal, in patients with autoimmune diseases on immunomodulatory agents is essential for effective treatment.

#5688 CLINICAL PROFILE AND OUTCOMES OF DENGUE-INDUCED ACUTE KIDNEY INJURY (DAKI): A TERTIARY CENTRE EXPERIENCE FROM SOUTH INDIA

Abstract Background and Aims Dengue is currently the most relevant viral infection transmitted by a mosquito bite that represents a major threat to public health worldwide. While Dengue-Associated Acute Kidney injury (DAKI) is a lethal complication, it remains as one of the least studied complications. Method This is a retrospective observational study amongst adult hospitalized Dengue patients admitted at a tertiary care hospital between January 2019 and December 2019. We estimated the prevalence of Acute Kidney Injury (AKI) using KDIGO AKIN (Acute Kidney Injury Network) criteria. Outcomes were analyzed during the time of discharge. Results Out of the 1550 hospitalized patients, majority of the patients were males – 1005 (64.9%). Most common age group was between 20 to 40 years. 85 (5.48%) of the total study patients developed DAKI. Older age groups were found to be more at risk for concurrent bacterial infections and higher mortality rate. Most patients had stage 1 AKI (70.1%). Overall mortality in patients with AKI was 20.3% and 80.5% in those requiring dialysis. The incidence of DAKI risk was increased by as much as 4.5-fold in the presence of hemoconcentration (or hematocrit > 46.5%). Older age, Male sex, co-existing viral hepatitis, Dengue Hemorrhagic Fever, Dengue Shock Syndrome, Rhabdomyolysis, Multiple Organ Dysfunction Syndrome were found to be independent risk factors for DAKI. Presence of DAKI was associated with higher mortality and longer hospital stay. Conclusion In our study population, we found a low prevalence of AKI but Mortality was high in patients requiring ICU care and dialysis. Prompt recognition and identification of the at-risk population and administration of appropriate supportive treatment should be aimed to reduce the morbidity and mortality associated with this common and very important tropical disease.

Injectable antibacterial Ag-HA/ GelMA hydrogel for bone tissue engineering.

Background: Fracture or bone defect caused by accidental trauma or disease is a growing medical problem that threats to human health.Currently, most orthopedic implant materials must be removed via follow-up surgery, which requires a lengthy recovery period and may result in bacterial infection. Building bone tissue engineering scaffolds with hydrogel as a an efficient therapeutic strategy has outstanding bionic efficiency.By combining some bionic inorganic particles and hydrogels to imitate the organic-inorganic characteristics of natural bone extracellular matrix, developing injectable multifunctional hydrogels with bone tissue repair effects and also displaying excellent antibacterial activity possesses attractive advantages in the field of minimally invasive therapy in clinical. Methods: In the present work, a multifunctional injectable hydrogel formed by photocrosslinking was developed by introducing hydroxyapatite (HA) microspheres to Gelatin Methacryloyl (GelMA) hydrogel. Results: The composite hydrogels exhibited good adhesion and bending resistance properties due to the existence of HA. In addition, when the concentration of GelMA is 10% and the concentration of HA microspheres is 3%, HA/GelMA hydrogel system displayed increased microstructure stability, lower swelling rate, increased viscosity, and improved mechanical properties. Furthermore, the Ag-HA/GelMA demonstrated good antibacterial activity against Staphylococcus aureus and Escherichia coli, which could signifificantly lower the risk of bacterial infection following implantation. According to cell experiment, the Ag-HA/GelMA hydrogel is capable of cytocompatibility and has low toxicity to MC3T3 cell. Conclusion: Therefore, the new photothermal injectable antibacterial hydrogel materials proposed in this study will provide a promising clinical bone repair strategy and is expected to as a minimally invasive treatment biomaterial in bone repair fields.

Risk factors of multidrug-resistant bacteria infection in patients with ventilator-associated pneumonia: A systematic review and meta-analysis

BackgroundMultidrug-resistant (MDR) bacteria-induced VAP often has high lethality. We present this systematic review and meta-analysis to assess the risk factors for MDR bacterial infection in patients with VAP. MethodsPubMed, EMBASE, Web of Science, and Cochrane Library were searched for studies regarding MDR bacterial infection in VAP patients, from Jan 1996 to Aug 2022. Study selection, data extraction, and quality assessment of included studies were conducted by two reviewers independently, and potential risk factors for MDR bacterial infection were identified. ResultsMeta-analysis showed that the score of the Acute Physiology and Chronic Health Evaluation II (APACHE-II) [OR = 1.009, 95% (CI 0.732, 1.287)], Simplified Acute Physiology Score II (SAPS-II) [OR = 2.805, 95%CI (0.854, 4.755)], length of hospital-stay before VAP onset (days) [OR = 2.639, 95%CI (0.387, 4.892)], in-ICU duration [OR = 3.958, 95%CI (0.894, 7.021)], Charlson index [OR = 1.000, 95%CI (0.889, 1.111)], overall hospital-stay [OR = 20.742, 95%CI (18.894, 22.591)], Medication of Quinolones [OR = 2.017, 95%CI (1.339, 3.038)], medication of carbapenems [OR = 3.527, 95%CI (2.476, 5.024)], combination of more than 2 prior antibiotics [OR = 3.181, 95%CI (2.102, 4.812)], and prior use of antibiotics [OR 2.971, 95%CI (2.001, 4.412)] were independent risk factors of MDR bacterial infection in VAP patients. Diabetes and mechanical ventilation duration before VAP onset showed no association with risk for MDR bacterial infection. ConclusionsThis study has identified 10 risk factors associated with MDR bacterial infection in VAP patients. Identification of these factors would be able to facilitate the treatment and prevention of MDR bacterial infection in clinical practice.

Most hospital patients at risk for bacterial infection undergo an anesthetic: implications for infection control practices related to the anesthesia workspace.

Even with nearly 100% compliance with prophylactic antibiotic protocols, many surgical patients (> 5%) develop surgical site infections, some caused by pathogens transmitted from the anesthesia workspace (e.g., anesthesia machine), including multidrug-resistant Staphylococcus aureus. Reducing contamination of the anesthesia workspace substantively reduces the risk of surgical site infections. We estimated the percentage of hospital patients at risk for health care-associated infections who may benefit from the application of basic preventive measures under the control of anesthesia practitioners (e.g., their hand hygiene). We conducted a retrospective cohort study which included every patient admitted to the University of Miami Health System from April 2021 through March 2022 for hospitalization, surgery, emergency department visits, or outpatient visits. Lists were created for the start date and times of every parenteral antibiotic administered and every anesthetic. Among 28,213 patient encounters including parenteral antibiotic(s), more than half (64.3%) also included an anesthetic (99% confidence interval, 62.2 to 66.6). The hypothesis that most antibiotics were administered during encounters when a patient underwent an anesthetic was accepted (P < 0.001). This observation may seem counterintuitive because parenteral antibiotics were administered for fewer than half of the 53,235 anesthetics (34.2%). The result was a consequence ofmost anesthetics (63.5%) atthe health system being conducted in nonoperating room locations, and only 7.2% of such patients received a parenteral antibiotic. Because approximately two-thirds of patients who receive an intravenous antibiotic also undergo an anesthetic, greater use of effective infection control measures in the anesthesia operating room workspace has the potential to substantively reduce overall rates of hospital infections.

Impact of bacterial infections prior to liver transplantation on post-transplant outcomes in patients with cirrhosis

Bacterial infections are frequent in patients with cirrhosis and increase the risk of death and drop-out from liver transplant (LT) waiting list. In patients with bacterial infections, LT is frequently delayed because of the fear of poor outcomes. We evaluated the impact of pre-LT infections on post-LT complications and survival. From 2012 to 2018, consecutive patients transplanted at the Hospital of Padua were identified and classified in two groups: patients surviving an episode of bacterial infection within 3 months before LT (study group) and patients without infections before LT (control group). Post-LT outcomes (complications, new infections, survival) were collected. A total of 466 LT recipients were identified (study group n= 108; control group n= 358). After LT, the study group had a higher incidence of new bacterial (57% vs. 20%, p <0.001) and fungal infections (14% vs. 5%, p= 0.001) and of septic shock (8% vs. 2%, p= 0.004) than the control group. Along with the model for end-stage liver disease (MELD) score and alcohol-related cirrhosis, bacterial infection pre-LT was an independent predictor of post-LT infections (odds ratio= 3.92; p <0.001). Nevertheless, no significant difference was found in 1-year (88% vs. 89%, p= 0.579) and 5-year survival rates (76% vs. 75%, p= 0.829) between the study group and control group. Within the study group, no association was found between the time elapsed from infection improvement/resolution to LT and post-LT outcomes. Patients with pre-LT infections have a higher risk of new bacterial and fungal infections and of septic shock after LT. However, post-LT survival is excellent. Therefore, as soon as the bacterial infection is improving/resolving, transplant should not be delayed, but patients with pre-transplant bacterial infections require active surveillance for infections after LT. Bacterial infections increase mortality and delay transplant in patients with cirrhosis awaiting liver transplantation (LT). Little is known about the impact of adequately treated infections before LT on post-transplant complications and outcomes. The study highlights that pre-LT infections increase the risk of post-LT infections, but post-LT survival rates are excellent despite the risk. These findings suggest that physicians should not delay LT because of concerns about pre-LT infections, but instead should actively monitor these patients for infections after surgery.

Gallic acid-grafted chitosan antibacterial hydrogel incorporated with polydopamine-modified hydroxyapatite for enhancing bone healing.

An open critical-size bone defect is a major medical problem because of the difficulty in self-healing, leading to an increased risk of bacterial infection owing to wound exposure, resulting in treatment failure. Herein, a composite hydrogel was synthesized by chitosan, gallic acid, and hyaluronic acid, termed "CGH." Hydroxyapatite was modified with polydopamine (PDA@HAP) and introduced to CGH to obtain a mussel-inspired mineralized hydrogel (CGH/PDA@HAP). The CGH/PDA@HAP hydrogel exhibited excellent mechanical performances, including self-healing and injectable properties. Owing to its three-dimensional porous structure and polydopamine modifications, the cellular affinity of the hydrogel was enhanced. When adding PDA@HAP into CGH, Ca2+ and PO4 3- could release and then promoted differentiation of BMSCs into osteoblasts. Without any osteogenic agent or stem cells, the area of new bone at the site of defect was enhanced and the newly formed bone had a dense trabecular structure after implanting of the CGH/PDA@HAP hydrogel for 4 and 8 weeks. Moreover, the growth of Staphylococcus aureus and Escherichia coli was effectively inhibited through the grafting of gallic acid onto chitosan. Above, this study provides a reasonable alternative strategy to manage open bone defects.

TOP-079 - Risk of bacterial infections in non-alcoholic fatty liver disease: a nationwide population-based cohort study

TOP-079 - Risk of bacterial infections in non-alcoholic fatty liver disease: a nationwide population-based cohort study

WED-368 - Impact of allelic HLA divergence on the risk of bacterial infections in cirrhotic patients awaiting liver transplantation

WED-368 - Impact of allelic HLA divergence on the risk of bacterial infections in cirrhotic patients awaiting liver transplantation

FRI-551 - Lower free and total serum cortisol levels are associated with higher risk of bacterial infection and acute-on-chronic liver failure in stable outpatients with advanced chronic liver disease

FRI-551 - Lower free and total serum cortisol levels are associated with higher risk of bacterial infection and acute-on-chronic liver failure in stable outpatients with advanced chronic liver disease

WED-343 - Serum PDL1 levels are associated with increased risk of bacterial infections in non-hospitalised patients with cirrhosis

WED-343 - Serum PDL1 levels are associated with increased risk of bacterial infections in non-hospitalised patients with cirrhosis

Development and In Vitro Analysis of Layer-by-Layer Assembled Membranes for Potential Wound Dressing: Electrospun Curcumin/Gelatin as Middle Layer and Gentamicin/Polyvinyl Alcohol as Outer Layers.

Nanofibrous membranes made of hydrogels have high specific surface areas and are suitable as drug carriers. Multilayer membranes fabricated by continuous electrospinning could delay drug release by increasing diffusion pathways, which is beneficial for long-term wound care. In this experiment, polyvinyl alcohol (PVA) and gelatin were used as membrane substrates, and a sandwich PVA/gelatin/PVA structure of layer-by-layer membranes was prepared by electrospinning under different drug loading concentrations and spinning times. The outer layers on both sides were citric-acid-crosslinked PVA membranes loaded with gentamicin as an electrospinning solution, and the middle layer was a curcumin-loaded gelatin membrane for the study of release behavior, antibacterial activity, and biocompatibility. According to the in vitro release results, the multilayer membrane could release curcumin slowly; the release amount was about 55% less than that of the single layer within 4 days. Most of the prepared membranes showed no significant degradation during immersion, and the phosphonate-buffered saline absorption rate of the multilayer membrane was about five to six times its weight. The results of the antibacterial test showed that the multilayer membrane loaded with gentamicin had a good inhibitory effect on Staphylococcus aureus and Escherichia coli. In addition, the layer-by-layer assembled membrane was non-cytotoxic but detrimental to cell attachment at all gentamicin-carrying concentrations. This feature could be used as a wound dressing to reduce secondary damage to the wound when changing the dressing. This multilayer wound dressing could be applied to wounds in the future to reduce the risk of bacterial infection and help wounds heal.

SARS-CoV-2 Immunity in Hematopoietic Stem Cell Transplant and Cell Therapy Recipients: What Do We Know, and What Remains to Be Determined?

Hematopoietic stem cell transplantation (HSCT) results in profound immunosuppression for the first few months after the procedure, requiring patients to be revaccinated against childhood vaccine-preventable infectious diseases. Patients who undergo allo-HSCT are at high risk of bacterial, fungal, and viral infections, with infectious complications responsible for at least one third of deaths. Even before the COVID-19 pandemic, respiratory virus infections were known to be more severe in HSCT recipients. The pandemic has highlighted the vulnerability of HSCT recipients, who experience an increased risk of morbidity and mortality after COVID-19 compared with healthy populations due to their severe immunodeficiency status. However, the current pandemic has also provided an exceptional scenario to better understand the immune response to SARS-CoV-2 cases and mRNA vaccines in HSCT recipients, including those receiving CD19-directed chimeric antigen receptor T cell (CAR-T) therapy. Researchers have focused on the role of the immune system in protecting against severe SARS-CoV-2 in patients with hematologic malignancies, including HSCT recipients. Insights gained during the pandemic will likely soon be used to improve preventive strategies in this population against viral infections in the near future. This narrative review summarizes the current knowledge on SARS-CoV-2 immunity in HSCT and cell therapy recipients following SARS-CoV-2 cases or vaccination.

A smart coating with integrated physical antimicrobial and strain-mapping functionalities for orthopedic implants.

The prevalence of orthopedic implants is increasing with an aging population. These patients are vulnerable to risks from periprosthetic infections and instrument failures. Here, we present a dual-functional smart polymer foil coating compatible with commercial orthopedic implants to address both septic and aseptic failures. Its outer surface features optimum bioinspired mechano-bactericidal nanostructures, capable of killing a wide spectrum of attached pathogens through a physical process to reduce the risk of bacterial infection, without directly releasing any chemicals or harming mammalian cells. On its inner surface in contact with the implant, an array of strain gauges with multiplexing transistors, built on single-crystalline silicon nanomembranes, is incorporated to map the strain experienced by the implant with high sensitivity and spatial resolution, providing information about bone-implant biomechanics for early diagnosis to minimize the probability of catastrophic instrument failures. Their multimodal functionalities, performance, biocompatibility, and stability are authenticated in sheep posterolateral fusion model and rodent implant infection model.

B1 B cells contribute to inflammation and metabolic dysfunction in aged adipose tissue during endotoxemia.

Abstract The elderly are at the greatest risk for severe endotoxemia and bacterial infections. The increase in low grade chronic inflammation and the decline of the immune response during aging contributes to this disease severity. Visceral adipose tissue (vWAT) exhibits immune recruitment and activation during pathogen challenge and metabolic diseases. Immune cells regulate lipolysis in vWAT which is required for the regulation of inflammation, but the intersection of bacterial inflammation and metabolism during aging is not clear. We investigated the contribution of B cells to metabolic dysfunction and inflammation during endotoxemia in vWAT. Old vWAT exhibited elevated inflammation and altered activation of resident B cells during LPS-induced endotoxemia. LPS also induced vWAT lipolysis in young mice but not in old mice. Diet induced obesity resulted in elevated LPS-induced inflammatory cytokines and B cells that failed to become activated by LPS. Deficiency of total B cells improved the homeostatic balance of immune cells within vWAT microenvironment, resulting in increased lipolysis and reduced Tnfα during endotoxemia in old mice. In contrast, B2 B cell depletion was insufficient to increase LPS-induced lipolysis or reduce inflammatory cytokines in vWAT from old mice, suggesting a driving role for B1 cells. B1 B cells from young and old vWAT were differentially activated by LPS indicating age-associated dysfunction. Our results demonstrate that endotoxemia results in immune and metabolic activation within the vWAT, both of which are dysfunctional during aging. These data reveal B cell subsets may differentially impair lipolysis and exacerbate the inflammatory response in vWAT following pathogenic challenge. Supported by grants from NIH (R00 AG058800, R01 AG079913)