Innate Immune Response and Sepsis Quiz
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Questions and Answers

What role do pathogen-associated molecular patterns (PAMPS) play in the innate immune response?

  • They activate adaptive immunity through T-cell differentiation.
  • They act as signals derived from necrotic cells.
  • They elicit an immune response by binding to specific receptors. (correct)
  • They cause direct tissue damage leading to inflammation.

    • How do superantigens initiate the process leading to sepsis or systemic inflammatory response syndrome (SIRS)?

  • By activating specific cytotoxic T lymphocytes.
  • By promoting selective B-cell activation and antibody production.
  • By causing polyclonal T-cell activation and cytokine release. (correct)
  • By directly damaging endothelial cells in blood vessels.

    • What is a consequence of the intranuclear translocation of nuclear factor kappa B (NF-kB) in the immune response?

  • Direct recruitment of neutrophils to the infection site.
  • Inhibition of inflammatory cytokine production.
  • Activation of complement pathways and cell proliferation. (correct)
  • Downregulation of TLR expression on immune cells.

    • Which of the following are described as danger signal molecules within the immune response?

    <p>DAMPS released from damaged cells.</p> Signup and view all the answers

    What can the concomitant activation of immune suppressive systems lead to during the SIRS response?

    <p>Increased risk of multiorgan dysfunction.</p> Signup and view all the answers

    What is the primary characteristic that distinguishes sepsis from SIRS?

    <p>Infection as the underlying cause</p> Signup and view all the answers

    What condition is classified as septic shock?

    <p>Hypotension despite aggressive fluid resuscitation</p> Signup and view all the answers

    What role do anti-inflammatory forces play in the context of sepsis?

    <p>They can lead to immunosuppression</p> Signup and view all the answers

    Which of the following is a symptom indicating the early stage of SIRS?

    <p>Non-specific symptoms and signs</p> Signup and view all the answers

    What is a critical measurement for diagnosing severe sepsis or septic shock?

    <p>Lactate level &gt; 2 mmol/L and MAP ≥ 65 mmHg</p> Signup and view all the answers

    Which factors can contribute to a dysregulated host response in sepsis?

    <p>Incorrect immune response to infection</p> Signup and view all the answers

    What is a common misconception about SIRS and severe sepsis?

    <p>They are terms still in widespread use</p> Signup and view all the answers

    Which characteristic of Diffuse Alveolar Damage occurs in the early stage of the condition?

    <p>Marked pulmonary edema</p> Signup and view all the answers

    What causes the clinical respiratory failure associated with Diffuse Alveolar Damage?

    <p>Decreased ability to oxygenate blood</p> Signup and view all the answers

    Which of the following is NOT a characteristic of classic Waterhouse-Friderichsen Syndrome?

    <p>Intra-alveolar edema</p> Signup and view all the answers

    What pathological change is typically seen in the intermediate stage of Diffuse Alveolar Damage?

    <p>Hyaline membranes</p> Signup and view all the answers

    Which factors contribute to endothelial and epithelial lung damage in Diffuse Alveolar Damage?

    <p>Cytokine and neutrophil-mediated inflammation</p> Signup and view all the answers

    What does the acronym NEWS stand for in the context of sepsis assessment?

    <p>National Early Warning Score</p> Signup and view all the answers

    Which factor contributes to the complexity of diagnosing sepsis?

    <p>Variability in patient populations, pathogens, and virulence</p> Signup and view all the answers

    What does recent evidence suggest about the use of immunosuppressive therapy for sepsis?

    <p>Their effectiveness varies and has not consistently proven beneficial</p> Signup and view all the answers

    Which statement regarding sepsis statistics is true?

    <p>Over classification can lead to falsely reduced mortality estimates</p> Signup and view all the answers

    What potential harm arises from rushing to diagnose sepsis?

    <p>Increased emergence of antibiotic-resistant organisms</p> Signup and view all the answers

    What does the term 'lacto-biotic reflex' refer to in sepsis diagnosis?

    <p>Adverse effects including overdiagnosis and misdiagnosis</p> Signup and view all the answers

    How does the use of Modified Early Warning Score (MEWS) impact patient outcomes?

    <p>It may lead to overclassification of sepsis cases</p> Signup and view all the answers

    What is a significant challenge in sepsis management related to mortality data?

    <p>Underestimation of true sepsis mortality in low healthcare access areas</p> Signup and view all the answers

    What implication can arise from a failure to consider alternative diagnoses in potential sepsis cases?

    <p>Delayed accurate diagnosis with potential treatment complications</p> Signup and view all the answers

    What is the primary purpose of conducting a thorough history and physical examination in suspected sepsis cases?

    <p>To use clinical judgement alongside structured scoring systems</p> Signup and view all the answers

    Study Notes

    Innate Immune Response

    • The innate immune system responds to PAMPs (Pathogen-associated molecular patterns) and DAMPS (Damage-associated molecular patterns).
    • PAMPS are molecules derived from microbes or microbial toxins that elicit an innate immune response.
    • DAMPS are danger signal molecules derived from necrotic cells that elicit a response similar to PAMPS.

    Superantigens

    • Superantigens are bacterial proteins, usually toxins, that cause polyclonal T-cell activation resulting in massive cytokine release.
    • Examples of bacteria that release superantigens include:
      • Staphylococcus aureus (Toxic shock syndrome)
      • Streptococcus pyogenes (Group A strep, Streptococcal toxic shock)

    Sepsis and Sepsis 3

    • SIRS (Systemic inflammatory response syndrome) is a systemic inflammatory response to infection or other insults such as trauma, burn, or pancreatitis.
    • Sepsis is SIRS with an infectious etiology.
    • Severe sepsis is sepsis with organ dysfunction.
    • Septic shock is sepsis-induced hypotension despite fluids.
    • Sepsis 3 definition: Life-threatening organ dysfunction caused by a dysregulated host response to infection.
    • Septic shock is a subset of sepsis cases where circulatory and cellular/metabolic abnormalities increase mortality risk, needing elevated mean arterial pressure and lactate levels.

    Sepsis-Induced Coagulopathy (SIC)

    • Sepsis can induce a coagulopathy similar to DIC (Disseminated Intravascular Coagulation) but induced by sepsis.
    • Proinflammatory cytokines like TNF-alpha activate endothelial cells, stimulating coagulation pathways, particularly in smaller vessels.
    • This leads to decreased production of endothelial anticoagulant factors and decreased fibrinolysis, resulting in DIC/SIC.
    • DIC/SIC causes systemic activation of coagulation systems with widespread thrombosis and fibrinolysis.
    • Consumption of coagulation factors and platelets in smaller vessels can lead to bleeding and hemorrhaging in other locations.

    Sepsis, Neutrophils, and NETs

    • Neutrophils are the first line of defense to phagocytize pathogens, but they can also cause some organ damage.
    • NETs (Neutrophil Extracellular Traps) are secreted out to trap and contain microorganisms but can also damage endothelial cells and stimulate coagulation.
    • NETS stimulate both intrinsic and extrinsic coagulation pathways.
    • Damage to red blood cells (RBCs) as they try to pass through fibrin mesh nets results in schistocytes (torn RBCs) and microangiopathic hemolytic anemia.

    Diffuse Alveolar Damage (DAD) and ARDS

    • DAD (Diffuse Alveolar Damage) is the pathological finding of damage to pulmonary endothelium and epithelium caused by neutrophils and cytokines.
    • It leads to:
      • Clinical respiratory failure: decreased PaO2/FiO2 and pulmonary infiltrates
      • Increased vascular permeability and pulmonary edema
      • Hyaline membranes and type 2 pneumocyte hyperplasia
      • Fibrosis in the late stages
    • DAD can cause ARDS (Acute Respiratory Distress Syndrome): inability to oxygenate blood and widespread tissue hypoxia.

    Obfuscating Data Regarding Sepsis

    • Mortality statistics vary with different countries and populations.
    • Overclassification of sepsis due to varied coding, MEWS, and fear of missing cases likely leads to false estimations of reduced mortality.
    • Deaths from sepsis are likely higher than acknowledged in countries with limited healthcare facilities and documentation.

    Potential Harms of Rushing Sepsis Diagnosis

    • Overuse of antibiotics: leads to increased emergence of drug-resistant microorganisms.
    • Failure to consider other diagnoses: leads to overuse of sepsis protocols and delays in making the correct diagnosis.
    • Overestimation of sepsis incidence and underestimation of true sepsis mortality rate.

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    Related Documents

    Sepsis and Shock PDF

    Description

    Test your knowledge on the innate immune response, including the roles of PAMPs and DAMPS. This quiz also covers superantigens and their effects on T-cell activation, along with key concepts related to sepsis and SIRS. Perfect for students studying immunology and infectious diseases.

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