LFD-AsPaeds

Evaluating the test performance of Aspergillus antigen detection using a lateral-flow device (LFD) on broncho-alveolar lavage (BAL) fluid for the diagnosis of invasive pulmonary Aspergillosis in Paediatrics: A Pilot Study.

In Set-up

Aims of the study

Primary

  • To assess the sensitivity and specificity of LFD on BAL fluid to diagnose pulmonary IA

Secondary

  • To establish the additional benefit of combining LFD on BAL fluid with standardised fungal diagnostics (PCR and galactomannan) in identifying pulmonary IA.
  • To set the bases of future long scale studies on fungal diagnostics in the paediatric population.

Inclusion Criteria

  • Paediatric patients aged less than 18 years who are clinically identified as requiring investigation for pulmonary IA/IFD and hence are undergoing a BAL as part of clinical care
  • Written Informed Consent

Exclusion Criteria:

  • Patients who are undergoing a BAL for other indications than suspected invasive fungal lung disease
  • Patients ≥ 18 years of age

The following data will be collected:

a) High resolution CT chest

CT chest imaging forms part of the routine investigations which patients will have already undergone for suspected invasive fungal disease prior to consent and an BAL being carried out.

b) Blood samples

Routine investigations carried out on blood samples will already have been obtained by the medical/nursing team responsible for the clinical care as part of the standard investigations for invasive fungal disease. This will include: GM, PCR, blood culture, FBC and will be carried out prior to the BAL as part of routine investigations.

c) LFD carried out on BAL fluid

Following the confirmation of consent, BAL fluid will be obtained by MLB (volume required for LFD is 70 uL). For the purposes of the study the BAL fluid will be added to the port of the LFD device and incubated at room temperature for 15 min. There are two points at which to read the LFD. The first is the test zone (T) where the antibody is bound. A red line at the test zone indicates a positive test- meaning the Aspergillus-specific antigen window is red within 15 minutes. This indicates antigen level of equal to or greater than 30ng/ml. This will be recorded as: 0 (absent, negative test) +1 (weakly positive) or 2++ (strongly positive) as indicated. The second place to read the LFD strip is the control zone. A red C line indicates the test has been performed correctly(1).

d) PCR on BAL fluid

This will be carried out in the laboratory as part of standard care.

e) GM on BAL fluid

This will be carried out in the laboratory as part of standard care. The cut off for GM in BAL fluid will be >1.0.

f) Follow up

Routine follow up will be carried out (the same standard of care as would occur if participants were not in the study). There will be no extra follow up required. Data will be collected at 2 weeks after the LFD was carried out and after 3 months. This will include: clinical status, microbiological results and treatments. The information will be recorded by delegated members of the Principal Investigators team.