30 Questions
Which type of hypersensitivity reaction involves antibodies that react with antigens on cell surfaces or in the extracellular matrix?
Type II hypersensitivity reaction
In Type II hypersensitivity reaction, what is the main mechanism of destruction that involves the formation of a membrane attack complex (MAC)?
Antibody and Complement-Mediated Destruction
What is the role of IgG and IgM in Type II hypersensitivity reaction?
Activating phagocytosis of target cells
Which condition is associated with Antibody-Dependent Cell-Mediated Cytotoxicity (ADCC) in Type II hypersensitivity reactions?
Erythroblastosis fetalis
In Type II hypersensitivity, which immune effector of the complement terminal pathway is involved in forming the membrane attack complex (MAC)?
C5-C9
Which of the following is NOT a main mechanism in Type II hypersensitivity reactions?
Antigen-Antibody Complex Formation
Which type of hypersensitivity reaction involves mainly T cells and not antibodies?
Type IV
What is the clinical manifestation of systemic lupus erythematosus?
Mistaken immune system attacks on healthy tissues
In which hypersensitivity reaction does macrophages/monocytes cause the damage with the help of CD4 T cells?
Type IV
Which type of reaction involves the deposition of immune complexes and activation of complement leading to a local vasculitis?
Arthus reaction
Which cell type is responsible for direct cell cytotoxicity in Type IV hypersensitivity reactions?
CD8 T cells
Which molecule plays a role in increasing phagocytosis by activating macrophages in Type IV hypersensitivity reactions?
Interferon-gamma (IFN-gamma)
Which type of hypersensitivity reaction involves the immune system mistakenly attacking self antigens?
Type IV
What is a common characteristic of autoimmune diseases?
More common in females
Which autoimmune disease is characterized by the immune system attacking one's own organs?
Rheumatoid arthritis
What may trigger the immune system to produce antibodies that attack the body's tissues in autoimmune diseases?
Unknown triggers
Which of the following is NOT a potential factor contributing to autoimmune diseases?
Food allergies
What is a key difference between Type IV hypersensitivity reactions and Type I hypersensitivity reactions?
Type I involves the immune system attacking self antigens, while Type IV does not.
What are common symptoms of Graves' disease?
Bulging eyes, weight loss, irritability
Which autoimmune disease involves antibodies attacking the thyroid gland?
Hashimoto's thyroiditis
What is a common symptom of hypothyroidism caused by Hashimoto's thyroiditis?
Fatigue
How does Myasthenia gravis affect muscle function?
Weakens muscles
What is the main medicine used to treat Myasthenia gravis?
Mestinon (pyridostigmine)
How is vasculitis treated?
By reducing immune system activity with prednisone
What autoimmune disease is characterized by the immune system attacking the nerves controlling muscles in the legs and sometimes the arms and upper body?
Guillain-Barre syndrome
Which autoimmune disease results in skin cells reproducing rapidly, leading to silvery, scaly plaques on the skin?
Psoriasis
In which autoimmune disease does the immune system produce antibodies that cause excess release of thyroid hormone?
Graves' disease
Which factor is not listed as a genetic risk factor for autoimmune diseases in the provided text?
HLA-C
Which autoimmune disease involves the immune system attacking and destroying insulin-producing cells in the pancreas?
Type 1 diabetes mellitus
What environmental factor is associated with an increased risk of autoimmune diseases based on the information provided?
Smoking
Study Notes
Immune Complexes
- Immune complexes form in circulation or in situ
- Can be generalized (systemic) or localized
Type III: Immune Complex-Mediated Clinical Examples
- Systemic lupus erythematosus: immune system mistakenly attacks healthy tissue, affecting skin, joints, kidneys, brain, and other organs
- Arthus reaction: local vasculitis associated with deposition of immune complexes and activation of complement
Type IV Hypersensitivity
- Delayed type or cell-mediated
- Reactions involve mainly T cells
- T cells release lymphokines and mediate cytotoxicity
- Inflammation and tissue damage occur with T cell action
Type IV Hypersensitivity: T Cell Subtypes
- CD4 T cells (Helper T cells): delayed hypersensitivity, interact with macrophages/monocytes
- CD8 T cells (Cytotoxic T cells): direct cell cytotoxicity
- Cytokines: IFN-γ (macrophage activation), IL-1 (lymphocyte-activating factor), TNFα (pro-inflammatory agent)
Type II Hypersensitivity Reaction
- Antibody-mediated/cytotoxic type
- Antibodies react with antigens on cell surfaces or in extracellular matrix, causing disease by cell destruction, inflammation, or functional interference
- Antigenic determinants: intrinsic or exogenous
Type II: Antibody-Mediated (Cytotoxic Type)
- Reaction involves IgG and IgM binding to antigens on target cell surfaces, leading to phagocytosis or lysis by complement activation
- 3 main mechanisms:
- Antibody and complement-mediated destruction
- Antibody-dependent cell-mediated cytotoxicity (ADCC)
- Opsonization and phagocytosis
Clinical Examples of Type II Hypersensitivity
- Blood transfusion reactions
- Erythroblastosis fetalis
- Autoimmune hemolytic anemia
Autoimmune Diseases
- Condition where the immune system mistakenly attacks the body
- Destruction of self-antigens by the immune system
- Genetic and environmental factors contribute to susceptibility
- Common in females
Examples of Autoimmune Diseases
- Systemic lupus erythematosus (SLE)
- Rheumatoid arthritis (RA)
- Sjogren syndrome
- Hashimoto's thyroiditis
- Type 1 diabetes mellitus
- Multiple sclerosis
- Inflammatory bowel disease
- Hypersensitivity reactions
- Immunodeficiency syndromes
Factors Contributing to Autoimmune Diseases
- Genetic factors: HLA-A, HLA-DRB1, HLA-DQB1, HLA-DRA
- Environmental factors: Epstein-Barr virus infection, smoking, sun exposure
Test your knowledge on Type II hypersensitivity reaction, which involves the production of IgG antibodies that react with antigens on cell surfaces or in the extracellular matrix. Learn about the mechanism where antibodies cause disease by destroying cells, triggering inflammation, or interfering with normal functions.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
