Immunology II - Immunologically Mediated Diseases

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What are immunologically mediated diseases?

Diseases caused by an immune response to invading agents or auto immune reactions leading to tissue or organ dysfunction or destruction.

What is an immune response?

A complex sequence of events triggered by stimuli (immunogen or antigen) leading to the elimination of the provoking agent.

What is an immunogen?

A molecule that can induce an immune response.

What is an antigen?

A molecule capable of reacting with antibodies or immune system products. Signup and view all the answers

What types of immunity do our bodies produce?

Both A and B Signup and view all the answers

Which factors are involved in the innate immune system?

Complement proteins Signup and view all the answers

Which cells are part of the adaptive immune system?

B cells Signup and view all the answers

The immune response is the same regardless of whether the antigen is encountered for the first time or subsequently.

False Signup and view all the answers

What are the three main types of immunologically mediated diseases?

Immunodeficiency diseases, allergy diseases, autoimmune diseases. Signup and view all the answers

Immunodeficiency diseases can lead to an increased susceptibility to infections.

True Signup and view all the answers

What might cause immunodeficiency diseases?

All of the above Signup and view all the answers

Which of the following are notable dermatological conditions associated with immunodeficiency disorders?

Eczema Signup and view all the answers

Increased susceptibility to opportunistic infections is a symptom of primary immunodeficiency disorders.

True Signup and view all the answers

Name one genetic defect associated with primary immunodeficiency disorders.

Genetic defects of missing enzymes Signup and view all the answers

The primary immunodeficiency disorder commonly known as X-linked A gammaglobulinaemia is also called ___ disease.

Bruton's Signup and view all the answers

Which of the following is NOT classified under primary T cell immunodeficiency?

Selective IgA deficiency Signup and view all the answers

Match the following primary immunodeficiency disorders with their descriptions:

X-linked A gammaglobulinaemia = Deficiency of B cell tyrosine kinase Di George syndrome = Thymic hypoplasia leading to T cell deficiency Wiskott-Aldrich syndrome = Immunodeficiency with dermatitis and thrombocytopenia Chronic granulomatous disease = Impaired ability to kill certain bacteria Signup and view all the answers

What is a major characteristic of patients with X-linked A gammaglobulinaemia?

Profound hypogammaglobulinaemia Signup and view all the answers

Study Notes

Introduction to Immunologically Mediated Diseases

Immunologically mediated diseases (IMDs) arise from immune responses to invading microorganisms or autoimmune reactions against host tissues.
These diseases can disrupt or destroy the function of organs and systems in the body.

Immune Response and Types

Immune response (IR) involves a sequence of events triggered by antigens (immunogens) that aims to eliminate the invading agents.
Immunogens induce immune responses, while antigens can react with immune products, specifically antibodies, but may not always trigger a response.
There are two primary immune response types:
- Innate Immune Response: Natural immunity, not specific to pathogens.
- Adaptive Immune Response: Specific immunity developed after exposure to pathogens.

Differences Between Innate and Adaptive Immune Systems

Innate Immunity
- Type: Natural
- Physical barriers: Skin and mucous membranes
- Cells: Macrophages, neutrophils, and NK cells
- Specificity: No antigen specificity
- Memory: No memory of previous encounters
Adaptive Immunity
- Type: Acquired
- Cells: T cells and B cells
- Specificity: Yes, highly specific to antigens
- Memory: Yes, retains memory of past infections

Routes of Entry for Immunogens

Immunogens can enter the body via:
- Bloodstream: Targets the spleen as the main immune response site.
- Skin: Travels through lymphatic vessels to lymph nodes.
- Mucosal surfaces: In respiratory or gastrointestinal tracts, affecting tonsils or Peyer's patches.

Mechanism of Immune Response

The immune system distinguishes self from non-self and typically reacts against non-self antigens.
Initial exposure to an antigen elicits a weak immune response, whereas subsequent exposures result in a stronger, enhanced specific response.

Characteristics of Adaptive Immune Response

Features include specificity toward antigens and the ability to retain memory.
Primary cell types: Monocytes, T lymphocytes (T cells), and B lymphocytes (B cells).
Interactions occur directly or via interleukins produced by these cells.

Types of Immunologically Mediated Diseases

IMDs are categorized into three main types:
- Immunodeficiency Diseases: Characterized by insufficient immune response.
- Allergies or Hypersensitivity Diseases: Harmful excessive immune reactions to harmless substances.
- Autoimmune Diseases: The immune system mistakenly attacks its own tissues.

Immunodeficiency Diseases

Result from deficiencies in components of the immune system:
- Antibody-mediated immunity (B cells)
- Cell-mediated immunity (T cells)
- Phagocytosis (macrophages and neutrophils)
- Complement system: Essential for immune responses and cell lysis.

Causes of Immunodeficiency

Deficiencies can be congenital (genetic) or acquired (e.g., viral infections, drug abuse).
Vitamin deficiencies (e.g., B12) and autoantibodies can also lead to immune dysfunction.

Clinical Features of Immunodeficiency

Highly Suspicious Features: Chronic or recurrent infections, unusual pathogens, or poor treatment response.
Moderately Suspicious Features: Skin rash, chronic diarrhea, hepatosplenomegaly, growth failure.
Specific Features: Ataxia, thrombocytopenia, conditions like eczema.

Evaluation of Immunodeficiency

Assessments include measuring immunoglobulin levels and performing skin tests for delayed-type hypersensitivity.
Phagocytic function and complement levels are also evaluated to determine the nature of deficiency.

Primary vs. Secondary Immunodeficiencies

Primary Immunodeficiency (PID): Usually genetic and involves developmental issues in lymphocytes.
Secondary Immunodeficiency: Results from other conditions affecting immune function, such as HIV, malnutrition, or chemotherapy.

Symptoms and Classification of Primary Immunodeficiencies

Recurrent respiratory infections, mucosal infections, and failure to thrive.
Classified into categories based on the type of cell affected:
- B cell deficiencies: e.g., X-linked agammaglobulinemia.
- T cell deficiencies: e.g., DiGeorge syndrome.
- Phagocytic or complement deficiencies.

Understanding these key points about immunologically mediated diseases provides a solid foundation for further study in immunology and its applications in pharmacy and medicine.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

This quiz covers the key concepts of immunologically mediated diseases as introduced in the Immunology II course. Learn about the definitions, classifications, and implications of these diseases. Perfect for students in the Faculty of Pharmacy and anyone interested in microbiology and immunology.