Tuberculosis and Sarcoidosis Flashcards
1
Q
How do you diagnose Active tuberculosis
A
- CXR
- sputum smear
- Sputum culture - Gold standard
- NAAT - more specific than a sputum smear
2
Q
How do you treat tuberculosis for active TB and for latent TB
A
Active TB
- Rifampicin - full 6 months (if they have TB of the CNS then 10 months)
- Isoniazid - full 6 months (if they have TB of the CNS then 10 months)
- Pyrazinamide - first 2 months
- Ethambutol - first 2 months
Latent TB
- 3 months of isoniazid and rifampicin or 6 months of isoniazid
3
Q
What would you find in a biopsy of sarcoidosis
A
- non caseating granuloma
4
Q
What is the treatment for sarcoidosis and what are the indications for these treatments
A
If symptomatic:
- steroids
- Anti-TNF
Indications
- parenchymal lung disease on CXR
- uveitis
- hypercalcaemia
- neurological ro cardiac involvement
5
Q
What is the prognosis of sarcoidosis
A
- 80% have no problem
- 20% lung, eye - steroid treatment
- 2% - brain and lung transplant
6
Q
What causes TB
A
- mycobacterium tuberculosis
- M. bovis
- Mycobacterium africanum
7
Q
What stain is used to diagnose TB in a sputum smear
A
Zihel nelson stain
8
Q
What is a microscopic feature of TB
A
Chording - when the M Tuberculosis bacteria stick together
9
Q
What does a CXR look like of tuberculosis
A
- Upper Lobe cavitation
- Bilateral hilar lymphadenopathy (BHL)
10
Q
How many people worldwide are affected by TB
A
- 3 billion infected (latent TB)
- 12 million cases at any one time
- 10.4 million new cases each year
- 2.6 million infectious diagnosed cases
11
Q
What are the risk factors for developing TB
A
- recent contacts
- migrants from high incidence areas
- people who work or reside in homeless shelters and prison
12
Q
What is the risk factor for developing serious problems from TB
A
Immunosuppression
- HIV
- Substance abuse
- silicosis
- kidney disease
- Diabetes
- low body weight
- transplant
- head and neck cancer
13
Q
what are the social risk factors for TB
A
- alcohol misuse (5%)
- homelessness (5%)
- drug use (4.3%)
- imprisonment (3.5%)
14
Q
how does TB affect the most deprived versus the least deprived
A
56% TB cases in the most deprived versus 7.4% in the least deprived
15
Q
how much of TB does multi resistant TB make up
A
3.5% of all TB
16
Q
What is multi resistant TB (MDRTB)
A
TB that is resistant to
- isoniazid
- rifampicin
17
Q
what is XDRTB (extremely drug resistant TB)
A
cases where people are resistant to isoniazid, rifampicin as well as the 2nd line drugs such as
- amikacin
- fluroquinolones
- cure rate is 35%
- historical cure rate without treatment is 33%
18
Q
What is the DOTS strategy (directly observed treatment) and what criteria is needed in order for DOTs to take place
A
- This is whereby a nurse comes every morning to make sure that the person is taking the medication and watches them take it to prevent the development of multi resistant TB
Conditions:
- those who have previously been treated for TB
- history of homelessness, drug or alcohol Misuse,
- in prison
- major psychiatric, memory or cognitive disorder
- in denial of TB diagnosi s
- have multi drug resistant TB
- are too ill to administer medication themselves
19
Q
What TB symptoms do you need to know
A
- cough
- fever
- night sweats
- weight loss
20
Q
What are the common and uncommon symptoms of TB
A
Common
- cough
- sputum
- fever
- malaise
- loss of appetite
Uncommon
- haemoptysis
- night sweats
- weight loss
- lymphadenopathy
21
Q
What do you ask when someone coughs up blood
A
- when did it start
- what time of day
- how much
- bright or dark red
- streak or blob
22
Q
what can cause you to cough up blood
A
- pulmonary embolism
- tuberculosis
- lung cancer
- bronchiectasis
- aspergilloma
- anticoagulation
23
Q
What are the ways in which the body can react to TB
A
- immediate clearance
- latent infection
- primary disease
- reactivation disease
24
Q
describe primary TB
A
- TB with no pre-exsiting immunity
- non infectious
- high mortality in immunocompromised
- often outside the lung
- children and elderly
- HIV co-infection
25
Describe post-primary TB
- TB with pre-existing immunity
- infection
- cavities with TB biofilm
- well tolerated
- young adults
- immunocompetent - CD4, CD8
26
How do you diagnosis of TB
Sputum
- PCR: Mtb and drug resistant
- culture and drug sensitivity testing
CXR
Inflammatory markers
Histology
27
Name ways to diagnosing TB
- CXR
- microscopy ziehl nelson stain - Sputum smear
- sputum culture - GOLD STANDARD
- interferon gamma release assay
- manntoux test
- gene Xpert MTB/RIF
- genotype MDRTBPlus
28
Isoniazid
- action
- site of action
- adverse effects
Action
- Bactericidal
Site of action
- cell wall - Inhibits mycolic acid synthesis
Adverse effects
- Liver damage
- peripheral neuropathy
- nausea
- tiredness
29
Rifampicin
- action
- site of action
- adverse effects
Action
- Bacteriostatic
Site of action
- Ribosome - inhibits bacterial DNA dependent RNA polymerase preventing the transcription of DNA into mRNA
Adverse effects
- liver damage
- flu like symptoms
- low platelets
- makes urine go orange
30
Pyrazinamide
- action
- site of action
- adverse effects
Action
- Bacteriostatic
Site of action
- converts into pryazinamic acid which makes the pH of the bacteria acidic and inhibits fatty acid synthase
Adverse effects
- flushing
- arthritis
- liver damage
- gout
31
Ethambutol
- action
- site of action
- adverse effects
Action
- Bacteriostatic
Site of action
- cell wall - inhibits the enzyme arabinosyl transferase which polymerises arabinose into Arabinan
Adverse effects
- Optic neuritis
32
how many people can a TB patient affect
- 10-15 people
Depends on
- smear positive - 10000 organisms/ml of sputum
- how many people they met t
33
describe the management of TB
Stage 1
- If they have symptoms
Stage 2
- Mantoux if under 65 years
- chest x ray if over 65 years
Investigations
- send sputum early
- chest x ray (if not done)
- inflammatory markers
- immunological test
34
What happens in the Mantoux test
- purified protein derviative - collection of TB antigens injected
- the hard area is then measured in 48 hours
- can be positive in people who have BCG
- greater than 15mm suggests TB infection
35
What is the gold standard for diagnosing latent TB
- QuantiFERON - TB gold - used with the ELISA
36
What does BCG vaccine do
- Attenuated M.bovis
- cell mediated response
- destroys the surrounding tissue
- forms memory cells
- forms scar
- some protection against active disease
37
What does BCG stand for
- Bacillus Calmette- Guerin
38
why do they think sarcoidosis occurs
- exaggerated immune response
39
What is the incidence of sarcoidosis
- 1 - 35.5 per 100,000 (5% of TB)
- Less than 64 per 100,000
- age 25-45 (2nd peak in 50-70 in females)
40
What are the symptoms of sarcoidosis
Acute symptoms
- erythema nodosum
- BHL
- swinging fever
- polyarthralgia
Insidious symptoms
- dysnpneoa
- non productive cough
- malaise
- weight loss
Skin
- lupus pernio
Hypercalameia
Other
- breathlessness
- thirst/polyuria
- neurological
- uveitis
41
What happens in sarcoidosis to
- FBC
- calcium
- CRP
- SACE
- CXR
- IGRA
- FBC = normal
- calcium = raised
- CRP = normal
- SACE = raised
- CXR = Bilateral Hilar Lymphadenopathy, midzones
- IGRA = 5% are positive
42
Describe the diagnosis pathway of sarcoidosis
```
Diagnosis and Investigations
First line
CXR
- Stage 0 – normal
- Stage 1 – BHL
- Stage 2 – BHL and intersitial infiltrates
- Stage 3 – diffuse intersitital infiltrates
- Stage 4 – diffuse fibrosis
```
Others
- Spirometry – restrictive defect
- Tissue biopsy – non caseating granuloma
Biopsy
- Exclude other causes of granuloma
- Greater than in 1 organ – exclude other causes of multi system granulomatous diseases
43
What syndromes are associated with sarcoidosis
Lofgrens Syndrome
- An acute form of the disease characterised by bilateral hilar lymphadenopathy, Erythema nodosum, fever and polyarthralgia
Heerfordt’s syndrome
- Parotid enlargement, fever, uveitis secondary to sarcoidosis
44
What is the treatment of sarcoidosis
- Most of the time it goes away on its own - monitor lung function and SACE
Symptomatic
- Steroids
other indications for treatment
- hypercalaemia
- eye disease
- neurological disease
- worsening lung function
45
What investigations can be used to confirm the diagnosis of extra-pulmonary sarcoidosis
- bronchoalveolar lavage
- ultrasound - hepatosplenomeagly
- bone x rays
- CT/MRI
46
What are the indication for corticosteroid treatment in sarcoidosis
- parenchymal lung disease
- uveitis
- hypercalacaemia
- neurological or cardiac involvement
47
What else can cause a bilateral hilar lymphadenopathy
- Sarcoidosis
• Infection, eg tb, mycoplasma
• Malignancy, eg lymphoma, carcinoma, mediastinal tumours
• Organic dust disease, eg silicosis, berylliosis
• Hypersensitivity pneumonitis
• Histocytosis x (Langerhan’s cell histiocytosis).
