Pulmonary aspergillus fumigatus Flashcards Preview

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Flashcards in Pulmonary aspergillus fumigatus Deck (46)
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1
Q

what is the most important opportunistic mould pathogen of Immuno-compromised humans

A

aspergillus fumigatus

2
Q

who are particularly vulnerable

A

people with haematological malignancy and allogeneic bone marrow transplant

3
Q

how many cases of invasive pulmonary aspergillosis

A

> 200,000 cases worldwide per year

4
Q

mortality rate of invasive pulmonary aspergillosis

A

30-95%

5
Q

chronic pulmonary aspergillosis

A

3 million cases worldwide in patients with underlying lung diseases

6
Q

allergic bronchopulmonary aspergillosis

A

4 million cases worldwide in patients with asthma and cystic fibrosis

7
Q

aspergilloma

A

a clump of mold which exists in a body cavity such as a paranasal sinus or an organ such as the lung.

8
Q

immunity against aspergilloma

A
  • inactive candida are inhaled
  • candida lodge in lower respiratory tract
  • condida swell

MACROPHAGES (block the candida from germinating to hyphae)

NEUTROPHILS block hype from invading tissue and inviting blood vessels where they can disseminate

9
Q

macrophages

A

block swelled candida from germinating to a hyphae

10
Q

neutrophil

A

stop hyphae from invading tissue

11
Q

if you are immunocompromised (have few macrophages and neutrophils)..

A

candida will be able to turn into hyphae, invade blood vessels and disseminate into the blood

12
Q

diagnosing IPA

A

no single ‘gold standad’

13
Q

what does diagnosis rely on

A

data from clinical, radiological, serological (GM and B-D gluten), molecular, histopathological and microbiological sources

14
Q

diagnosis should conform to what writer for probable or proven detection of IPI

A

EORTC/MSG

15
Q

what is important

A

that diagnosis is made without delay

16
Q

serological detection of aspergillus fumigatus

A

serum shows elevated antibodies against A.fumigatus surface components

17
Q

elevated antibody tigers shown to be due to the presence of abundnant

A

galactomannoprotein in the cell walls of the apthogen

18
Q

which abundant galactomannoprotein is found in the cell walls of the A.fumigatus, that antibodies mount a response against

A

Afmp1p

19
Q

Afmp1p can be detected using

A

western blotting

20
Q

diagnosis using ELISA

A

recombinant Afmp1p protein used to coat wells of microsite plate

  • sera taken from patients with aspergilloma, from patients with Invasive aspergillosis and patients with infections caused by other pathogenic fungi
  • EISa highly specific for A.fumigatus
21
Q

structure of the fungal cell wall

A

B-(1,6)- glucan on the outside and B-(1,3)- glucan makes up chitin (fungal cell wall)

  • Phospholipid bilayer with ergosterol
  • mannans and galactans
22
Q

traditional immunological test for IPA centred around

A

detection of circulating fungal cell wall - galactomannan

23
Q

what used to detect galactomannkn (GM)

A

rat mAb EB-A2 (DAS-ELISA)

24
Q

specificity of GM assay

A

> 85%

25
Q

negatives of GM assay

A

high false positives

26
Q

reasons for GM assay false positive

A

cross-reactivity of EB-A2 with GM from other species

cross reactivity of mAb with galacotoxylomanna from cryptococcus neoformans

detection of GM in B-lactam antibiotics derived from penicillin species

GM found in food products e.g. baby formulas

cross-reactivity of mAb with anti-cancer drug cyclophosphamide

27
Q

which other species have GM

A

Fusarium

28
Q

anti cancer drug

A

cyclophosphamide

29
Q

antibitoic

A

b-lactam

30
Q

GM common in

A

baby milk formulas- crosses the gut into blood stream

31
Q

another method of detection

A

pan-fungal detection

32
Q

pan fungal diagnostic detects

A

(1-3)- B-D- glucans

33
Q

(1-3)- B-D- glucans

A

glucose polymer

34
Q

(1-3)- B-D- glucans is found in

A

most fungi, some bacteria, higher plants

35
Q

(1-3)- B-D- glucans is up to

A

60% dry weight of fungal cell wall

36
Q

(1-3)- B-D- gluons forms the basis of the commerical

A

Fungitell test

37
Q

(1-3)- B-D- gluons - pan fungal diagnostics has a

A

high rate of false positives

38
Q

Mouse mAb JF5 is what type of immunoglobulin

A

IgG3

39
Q

Mouse mAb JF5 recognises

A

extracellular, constitutive, glycoprotein antigen

40
Q

antigen detected by Mouse mAb JF5 is secreted during

A

active growth of hyphae and is not produce by dead or quiescent spores

41
Q

Mouse mAb JF5 displays superior

A

specificity to mAb EB-A2 (Glucomannoproteins)

42
Q

EB-A2 is used in

A

Bio-Rad Platelia GM-ELISA

43
Q

Mouse mAb JF5 has been used to develop a

A

rapid, user-friendly, diagnostic test (lateral flow device) for detection of IPA

44
Q

Immunofluorescence localises

A

JF5 antigens to actively growing hyphae

45
Q

immunogold EM can be used to visualise

A

JF5 antigens released from growing hyphae (little dots around the structure)

46
Q

Mouse mAb JF5 can differentiate between

A

A.fumigatus and S.apiospermum