Immune Complexes and Hypersensitivity

The video explains type 3 hypersensitivity reactions, where antibodies bind to soluble antigens forming immune complexes that attach to tissues, activating the complement system and recruiting neutrophils. This can lead to localized reactions like Arthus reaction or systemic reactions seen in autoimmune diseases such as lupus and rheumatoid arthritis. The video concludes with questions to assess understanding.

What triggers a type 3 hypersensitivity reaction?

• Binding of antibodies to soluble antigens

• Direct attack by T-cells

• Binding of antibodies to cell surface antigens

• Activation of mast cells

What is the role of C5a in the complement cascade?

• It inhibits the complement cascade

• It serves as a chemotactic factor for neutrophils

• It forms the membrane attack complex

• It acts as an opsonin

Which of the following is NOT a site where immune complexes can attach?

• Synovium of joints

• Glomeruli of kidneys

• Epithelial lining of alveoli

• Nerve endings

Which of the following is an example of a localized type 3 hypersensitivity reaction?

• Systemic lupus erythematosus

• Serum sickness

• Farmer's lung

• Rheumatoid arthritis

What is the result of immune complexes forming at the site of a tetanus vaccination?

• Systemic inflammation

• Localized inflammation and induration

• Delayed-type hypersensitivity reaction

• Immediate hypersensitivity reaction

What condition is associated with cryoglobulins precipitating in circulation?

• Serum sickness

• Arthus reaction

• Raynaud's phenomenon

• Celiac disease

What is a common symptom of systemic type 3 hypersensitivity reactions?

• Shortness of breath

• Pallor and numbness

• Joint pain

• Localized rash

In lupus, where do large numbers of immune complexes typically attach?

• Epithelial lining of alveoli

• Endothelium of blood vessel walls

• Synovium of joints

• Nerve endings

What is the primary antibody involved in rheumatoid factor?

• IgM

• IgE

• IgD

• IgA

Which autoimmune disease is characterized by immune complexes causing joint damage?

• Celiac disease

• Rheumatoid arthritis

• Multiple sclerosis

• Lupus