Pathology of Pulmonary Infections

Question 1

What is pneumonia?

Answer 1

Infection involving the distal airspaces usually with inflammatory exudation where fluid filled spaces lead to consolidation

Question 2

Which types of organisms can cause pneumonia? (3)

Answer 2

Viruses
Bacteria
Fungi

Question 3

Which viruses can cause pneumonia?

Answer 3

Influenza
Parainfluenza
measles
Varicella-zoster
Respiratory syncytial virus (RSV)

Question 4

Which bacteria can cause pneumonia?

Answer 4

Chlamydia

Mycoplasma

Question 5

Fungal pneumonia only really occur in _______ patients

Answer 5

Immunocompromised

Question 6

What is lobar pneumonia?

Answer 6

Confluent consolidation involving a complete lung lobe

Question 7

What causes lobar pneumonia (organisms)

Answer 7

Strep pneumoniae or other organisms(Klebsiella/Legionella)

Question 8

What is the clinical setting of lobar pneumonia?

Answer 8

Usually community-acquired

Classically in otherwise healthy young adults

Question 9

What distinguishes between lobar and bronchopneumonia?

Answer 9

Morphology

Question 10

Pathology of lobar pneumonia involves a classical ______ __________ response

Answer 10

acute immune

Question 11

What are the possible complications of lobar pneumonia?

Answer 11

Fibrous scarring
Abscess
Bronchiectasis
Empyema

Question 12

What is bronchopneumonia?

Answer 12

Patches of pus/infection thought the lung

Mostly associated with airways

Question 13

What are the causes of bronchopneumonia?

Answer 13

COPD
Cardiac failure
Complicate not viral infection
Aspiration

Question 14

Which organisms are found in bronchopneumonia?

Answer 14

Strep. pneumoniae
Haemophilus influenza 
Staphylococcus 
Anaerobes 
Coliforms

Question 15

Aspiration-caused bronchopneumonia is associated with which organisms?

Answer 15

Staph
Anaerobes
Conforms

Question 16

What are the possible complications of bronchopneumonia?

Answer 16

Organisation (scarring)
(lung) Abscess
Bronchiectasis
Empyema

Question 17

What is bronchiectasis?

Answer 17

Chronic infection of the bronchi and bronchioles leading to permanent dilation of these airways

Question 18

What are the main organisms associated with bronchiectasis?

Answer 18

Haemophilia influenza
Strep pneumonia
Staph aureus
Pseudomonas aeruginosa

Question 19

What are the congenital causes of Bronchiectasis?

Answer 19

Cystic fibrosis
Young’s syndrome
Primary ciliary dyskinesia
Kartagener’s syndrome

Question 20

What are the post-infection causes of bronchiectasis?

Answer 20

Measles 
Pertussis 
Bronchiolitis
Pneumonia
HIV 
TB

Question 21

What are other other (non-congenital/non-post-infection) causes of bronchiectasis?

Answer 21

Bronchial obstruction
Allergic broncho-pulmonary aspergillosis 
Hypo-gammaglobulinaemia 
Rheumatoid arthritis 
Ulcerative colitis 
Idiopathic

Question 22

Tuberculosis is …

Answer 22

a mycobacterial infection found in many body sites

Question 23

What characterises the pathology of TB?

Answer 23

Delayed (type IV) hypersensitivity leading to granulomas with necrosis

Question 24

Which organisms are the main pathogens in TB?

Answer 24

M. tuberculosis

M. bovis

Question 25

What gives TB-causing-organisms their pathogenicity?

Answer 25

Ability to avoid phagocytosis and simulate a host-T-cell response

Question 26

What constitutes immunity in TB?

Answer 26

T-cell response to organism enhances macrophage ability to kill mycobacteria

Question 27

What constitutes hypersensitivity in TB?

Answer 27

T-cell response causes granulomatous inflammation, tissue necrosis and scarring

Question 28

What is meant by primary tuberculosis?

Answer 28

1st exposure and up to 5 years after

Question 29

What occurs when first exposed to TB?

Answer 29

Inhaled organism > phagocytosed > carried to hilar lymph nodes > immune activation > granulomatous response in nodes + lungs Usually causes killing of organism / sometimes overwhelming and spreads

Question 30

What is meant by secondary tuberculosis?

Answer 30

Reinfection or reactivation of disease in person with some immunity

Question 31

In secondary tuberculosis disease tends to be _______ (often in ___ of lungs) but can progress to spread by ______ or _______

Answer 31

localised apices airways bloodstreams

Question 32

Which tissue changes occur in primary TB?

Answer 32

Small focus (Ghan focus) in periphery / mid zone of lung

Question 33

What tissue changes occur in secondary TB?

Answer 33

Fibrosing and caveating apical vision

Question 34

What causes reactivation of TB?

Answer 34

decreased T-cell function

Question 35

What causes decreased T-cell function?

Answer 35

Age Coincident disease (HIV) Immunosuppressants (steroids/chemotherapy)

Question 36

When does reinfection with TB occur?

Answer 36

At higher dose or with more virulent organism

Question 37

What are opportunistic pathogens?

Answer 37

Pathogens that aren't normally disease causing but cause disease in immunocompromised patients

Question 38

What are examples of opportunistic pathogens that cause infection in the immunocompromised?

Answer 38

Viral (Cytomegalovirus - CMV) Bacteria (Mycobacterium avid intracellulare) Fungi (aspergillus / Candida / Pneumocystis) Protozoa (Cryptosponridia / toxoplasma)

Question 39

How is TB diagnosed?

Answer 39

high index of suspicion MDT Bronchoalveolar lavage Biopsy with stains