ATS 2021 will feature presentations of original research from accepted abstracts. Mini Symposia and Thematic Poster Sessions are abstract based sessions.
Please use the form below to browse scientific abstracts and case reports accepted for ATS 2021. Abstracts presented at the ATS 2021 will be published in the Online Abstract Issue of the American Journal of Respiratory and Critical Care Medicine, Volume 203, May 3, 2021.
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Identification of Sepsis Patient Immune Phenotypes Using a Microfluidic Assay
Session Title
TP53 - TP053 SEPSIS AND MULTIORGAN FAILURE
Abstract
A2725 - Identification of Sepsis Patient Immune Phenotypes Using a Microfluidic Assay
Author Block: R. Prosniak1, Q. Yang2, H. Wijerathne2, N. Marchetti1, M. Kiani2, L. Kilpatrick3; 1Department of Thoracic Medicine and Surgery, Temple University Hospital, Philadelphia, PA, United States, 2Mechanical Engineering, Temple University, Philadelphia, PA, United States, 3Physiology/CILR, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, United States.
Rationale: Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection with over 1.7 million cases/year and >250,000 deaths in the US. Septic patients often die of organ failure and therapies directed against endothelial cell dysfunction are important targets. Neutrophil dysregulation and neutrophil-endothelial cell interactions have a critical role in the early course of organ damage, but the underlying pathophysiology of neutrophil-mediated tissue damage is yet to be delineated. Recent studies have identified specific phenotypes in sepsis patients with different immune-response patterns and response to therapeutics (JAMA 321:2003, 2019). We, therefore, employed our novel biomimetic microfluidic assay (bMFA), that reproduces the entire leukocyte adhesion cascade in a physiologically realistic 3D environment encompassing circulation, rolling, adhesion and migration, to categorize sepsis patients into distinct phenotypes using patient data and microfluidics-based neutrophil function analysis.
Methods: Patients admitted to the ICU for advanced respiratory and hemodynamic support were recruited to the study. Following informed consent, heparinized blood was obtained and neutrophils isolated. Human lung microvascular endothelial cells (HLMVEC) were cultured under shear flow in the bMFA. Confluent endothelial cells were pretreated with buffer (no treatment) or cytomix (TNF-IL-1β-IFNγ, 10 ng/ml) for 4 hrs. Neutrophils were fluorescently labeled and adherence and migration across HLMVEC were measured in response to the chemoattractant fMet-Leu-Phe.
Results: Analysis of 16 ICU patients (n=14 with sepsis, n=2 with SIRS) as compared to age-matched healthy subjects (n=8) demonstrated 2 distinct immune cell phenotypes. A hypoinflammatory phenotype (n=9 patients) was characterized by decreased neutrophil migration across HLMVEC in response to both buffer-treated (0.4±0.2 for septic vs. 7±3 for healthy, P<0.01) and cytomix-treated (8±3 vs. 81±18, P<0.001). Neutrophil adherence to cytomix activated HLMVEC was also decreased compared to controls (627±98 vs. 874±93 P<0.05), but there were no significant differences in neutrophil adherence to buffer treated HLMVEC between the two groups. Conversely, the hyperinflammatory group had significantly increased neutrophil migration across cytomix-activated HLMVEC compared to controls (155±37 vs. 81±18, P<0.04). Preliminary analysis of clinical and laboratory data did not differentiate the two patient populations.
Conclusions: As these ICU patients look similar clinically, identification of patient phenotypes with diverse immune responses (hyperinflammatory vs. hypoinflammatory) may help determine who would benefit from specific treatments such as immunosuppressive therapies and who may be negatively impacted. Emerging technologies, such as microfluidic systems can help identify and personalize treatment for different sepsis patient phenotypes.
Author Block: R. Prosniak1, Q. Yang2, H. Wijerathne2, N. Marchetti1, M. Kiani2, L. Kilpatrick3; 1Department of Thoracic Medicine and Surgery, Temple University Hospital, Philadelphia, PA, United States, 2Mechanical Engineering, Temple University, Philadelphia, PA, United States, 3Physiology/CILR, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, United States.
Rationale: Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection with over 1.7 million cases/year and >250,000 deaths in the US. Septic patients often die of organ failure and therapies directed against endothelial cell dysfunction are important targets. Neutrophil dysregulation and neutrophil-endothelial cell interactions have a critical role in the early course of organ damage, but the underlying pathophysiology of neutrophil-mediated tissue damage is yet to be delineated. Recent studies have identified specific phenotypes in sepsis patients with different immune-response patterns and response to therapeutics (JAMA 321:2003, 2019). We, therefore, employed our novel biomimetic microfluidic assay (bMFA), that reproduces the entire leukocyte adhesion cascade in a physiologically realistic 3D environment encompassing circulation, rolling, adhesion and migration, to categorize sepsis patients into distinct phenotypes using patient data and microfluidics-based neutrophil function analysis.
Methods: Patients admitted to the ICU for advanced respiratory and hemodynamic support were recruited to the study. Following informed consent, heparinized blood was obtained and neutrophils isolated. Human lung microvascular endothelial cells (HLMVEC) were cultured under shear flow in the bMFA. Confluent endothelial cells were pretreated with buffer (no treatment) or cytomix (TNF-IL-1β-IFNγ, 10 ng/ml) for 4 hrs. Neutrophils were fluorescently labeled and adherence and migration across HLMVEC were measured in response to the chemoattractant fMet-Leu-Phe.
Results: Analysis of 16 ICU patients (n=14 with sepsis, n=2 with SIRS) as compared to age-matched healthy subjects (n=8) demonstrated 2 distinct immune cell phenotypes. A hypoinflammatory phenotype (n=9 patients) was characterized by decreased neutrophil migration across HLMVEC in response to both buffer-treated (0.4±0.2 for septic vs. 7±3 for healthy, P<0.01) and cytomix-treated (8±3 vs. 81±18, P<0.001). Neutrophil adherence to cytomix activated HLMVEC was also decreased compared to controls (627±98 vs. 874±93 P<0.05), but there were no significant differences in neutrophil adherence to buffer treated HLMVEC between the two groups. Conversely, the hyperinflammatory group had significantly increased neutrophil migration across cytomix-activated HLMVEC compared to controls (155±37 vs. 81±18, P<0.04). Preliminary analysis of clinical and laboratory data did not differentiate the two patient populations.
Conclusions: As these ICU patients look similar clinically, identification of patient phenotypes with diverse immune responses (hyperinflammatory vs. hypoinflammatory) may help determine who would benefit from specific treatments such as immunosuppressive therapies and who may be negatively impacted. Emerging technologies, such as microfluidic systems can help identify and personalize treatment for different sepsis patient phenotypes.
