Week 2, Lecture 4: Hypersensitivity RXNs

Question 1

Hypersensitivity onset depends on:

Answer 1

• original immunologic insult/injury
• hosts genetics
• specific type of immunologic rxn resulting in disease

Question 2

Hypersensitivity Predisposing factors

Answer 2

• age and gender (females>males; adults > children)
• genetics: patients w asthma history etc , develop drug allergies that are more severe than those without reactions
• associated illness
• previous drug exposure
• drug-related factors

Question 3

Drugs associated with allergic-like reactions

Answer 3

• beta lactam antimicrobial agents
• aspirin and NSAIDS
• sulfonamide drugs
• pharmaceutical additives
• cancer chemotherapy agents
• biologics

Question 4

Type 1 Hypersensitivity

Answer 4

• immediate allergy of anaphylaxis; rapidly developing immunologic reaction mediated by IgE antibody release following exposure to antigen
• -> causes atopic allergies
• evaluation and treatment: depends on severity of initial reaction and response to treatment; anaphylaxis=life threatening!
• fatality is greatest in the first few hours, observation for up to 12 hours

Question 5

Type 2 Hypersensitivity

Answer 5

-tissue specific reactions; antigen on target cell bind directly with antibody resulting in cellular destruction or function reduction
1) complement mediated lysis: AG attacks target cells, AB reacts with the AG present on the cell surface –> activates complement system
EX: ABO mismatches transaction RXN

2). macrophage mediated phagocytosis: cell destruction by macrophages once IgG and C3 opsonize target cell
EX: hemolytic anemia of newborn

3) neutrophil mediated immune destruction
4) antibody-dependent cytotoxic hypersensitivity

5) malfunction of target cells: does NOT destroy the cell
EX: hyperthyroid disease (Graves Disease)

Question 6

Type 2: hemolytic anemia of newborn symptoms

Answer 6

• hemolytic anemia (bilirubin rises and jaundice)
• high output heart failure (death)
• enlarged liver and spleen
• generalized swelling