Asthma, Cystic fibrosis and COPD

Question 1

What cells is asthma mediated by?

Answer 1

Mediated by:
• T-cell: TH2 type
• B- cells, produce IgE
• Mast cells, basophils and eosinophils

Question 2

Detail how asthma occurs, including first and second exposure in your response.

Answer 2

First step:
• First step is priming: you have first exposure to allergen, but with no response
• Antigen presenting cell to TH2 cell
• TH2 cell produces cytokines (IL4, IL-5)
• B-cells produce IgE
• IgE bins to mast cell

Second exposure to allergen
• IgE binds to mast cells and mast cells degranulate
• Histamine, prostaglandins and leukotrienes are released
• Histamine = bronchoconstriction, increased vascular permeability and increased mucous

Question 3

Describe the genetic causes of cystic fibrosis and the mode of inheritance

Answer 3

Cystic fibrosis
• Occurs due to genetic abnormality in exocrine gland secretion (affects glands that excrete)

Causes
• Mutation to the Cystic Fibrosis Transmembrane Regulator Gene
• Autosomal recessive
• CFTR: it forms a chloride channel on epithelial cell

Question 4

Describe the pathophysiology of CF.

Answer 4

• In a healthy situation, goblet cells produce mucous
• The mucous requires water to be rather liquidy
• In a healthy situation, chloride from CFTR channel goes from the cell and into the mucous, while some Na+ and H20 go from the mucous and into the cell
• If the chloride channel doesn’t work, there is a huge accumulation of chloride in the cell. To balance this, copious amount of Na+ and H20 exit the mucous and enter the cell
• This results in really dehydrated mucous
• The tracts can no longer move the mucous along
• This becomes a breading site for pathogens
• GI tract cannot absorb the food
• Sweat and salivary glands have a lot of chlorine and sodium = salty

Question 5

Describe the dental implications for a patient with cystic fibrosis

Answer 5

Respiratory infections

• Cough
• Physio, antibiotics, bronchodilators mgt.
• Caries

GIT problems

• Poor weight gain, greasy stools
• Vitamin supplements and calorie rich diet
• Delayed dental development

Salivary gland blockage

• Dry mouth
• Salivary supplements
• Caries and infections

Question 6

Identify in which age groups COPD is most common

Answer 6

40 and older

Question 7

Describe the pathophysiology of COPD

Answer 7

• Smoking causes epithelial cell damage
• Activates innate immune response: neutrophils
• Neutrophils release ROS which ends up destroying cells
• Adaptive immune response is activated: T cells (TH1) creates further damage

Question 8

Detail histological effects of COPD in airways.

Answer 8

• Airway clogged with neutrophils
• Increased mucous
• Narrowed airways
• Eventually alveoli disintegrate