Lateral flow devices (LFDs) are self-contained tests that work in a similar to a home pregnancy test. They can be used in a ward/clinic as part of a point-of-care (AKA ‘bedside’) testing programme, or in parts of the world without access to a mycology laboratory. Critical care units may use LFDs detecting Aspergillus cell wall antigens (galactomannan or beta-D-glucan) to help to diagnose invasive aspergillosis, giving a rapid result that can save a life. There is also an LFD for detecting Aspergillus antibodies (IgG/IgM) that is more suitable for diagnosing chronic forms of aspergillosis.

 

 

Researchers in Manchester used an Aspergillus IgG/IgM antibody LFD to test blood serum taken from 106 ABPA patients at NAC and the ManARTS Biobank, and compared them to control patients with asthma or bronchiectasis. The test performed well and was more sensitive for patients with bronchiectasis (94%) than without (79%). While Aspergillus IgG/IgM is only a minor criterion in the ABPA diagnosis guidelines, this LFD could be a very useful tool for screening severe asthma patients to detect signs of ABPA before they develop complications such as bronchiectasis or CPA. It would be particularly useful in remote or low-resource settings (e.g. parts of India) where a mycology laboratory is not easily available.

CPA is common among people who have lung damage caused by a previous tuberculosis (TB) infection, but cases are often missed because of lack of access to fungal diagnostics in the parts of the world where TB is most common. An Indonesian group looked at patients at a respiratory clinic in Jakarta who still had ongoing symptoms (fatigue etc) after being successfully treated for TB. Around 1 in 5 was found to have developed CPA – particularly those with diabetes or a history of smoking. A point-of-care Aspergillus IgG/Igm antibody test (from LDBio) was positive for 80% of patients with CPA, but also for 30% of those without CPA. The authors suggest that this test could be useful in similar clinics for screening for CPA while waiting for the diagnosis to be confirmed by cultures and a CT scan.