Point of care tests in the diagnosis of chronic and allergic aspergillosis

Lead Research Organisation: University of Manchester
Department Name: School of Biological Sciences

Abstract

Chronic and allergic forms of aspergillosis are an increasingly recognised global health problem. They are caused by the fungus Aspergillus, a very common environmental mould. We breathe in fungus particles daily, but we are usually able to clear them from the lungs. In some cases though, the fungus can establish itself in the lung and cause disease. This usually happens in people with weak immune systems, such as after chemotherapy for cancer, but can also happen on a background of chronic lung disease, like previous tuberculosis (TB) or chronic obstructive lung disease (COPD). This disease is termed chronic pulmonary aspergillosis (CPA).

One in 5 people is expected to develop CPA after successful treatment of TB: this means that CPA affects 1.2 million people globally as a consequence of TB. The number of new TB cases in Indonesia exceeds 1 million per year, making Indonesia the country with the 2nd largest number of TB cases in the world. As TB and CPA may present with the same symptoms, CPA may be mistaken and treated as TB. If CPA is not diagnosed and treated, it can result in lung destruction, weight loss, cough and blood in the sputum. Treatment exists in the form of antifungal medication. It is difficult to diagnose CPA, as diagnosis relies on specialist laboratory tests not available in most low and middle-income countries. A point-of-care (POC) blood test, performed in clinic without the need to send the sample to a laboratory would make CPA much easier and cheaper to diagnose.

We plan to use a recently developed POC test that detects Aspergillus antibody in blood in patients who present with suspected but not confirmed TB in Indonesia, and to compare with a standard serological test. The results will be made known to the physicians who can then decide on best treatment. So we can assess the importance of the result, we will follow the patients for 12 months for signs of deterioration in their symptoms and chest X-Ray. We will also compare the outcomes in patients who were treated with antifungal medication for CPA. We hope we can prove that the POC test can be used to diagnose CPA in low and middle-income settings.

In high-income settings where TB is less common, such as the UK, CPA mainly affects patients with chronic respiratory disease like COPD or bronchiectasis. The diagnosis is made by bronchoscopy and testing of bronchoalveolar lavage fluid for Aspergillus; however, the tests are neither sensitive nor specific. Turn around time, even for specialised labs, may be long and cost is high. A POC test for diagnosis of Aspergillus from pulmonary secretions would speed up diagnosis in this setting too. We plan to compare two POC tests with the conventional methods for the diagnosis of CPA in patients having bronchoscopies. As the gold-standard, we will use a new technology to analyse the entire population of fungi in the lung (called the mycobiome).

Allergic bronchopulmonary aspergillosis (ABPA) complicates 1-4% of cases of asthma globally. It results in poor control of asthma, frequent admissions to hospital and use of long-term steroids which have several side effects. Diagnosis requires either an allergy skin test or blood test. Treatment with antifungals improves symptoms and leads to reduced steroid use. There are more than 13 million asthmatics in Indonesia, and more than 300 thousand with ABPA according to estimates; the majority would be unrecognised if testing is not undertaken. Due to lack of diagnostic facilities, this is the case in most low and middle-income countries. A POC blood test detecting sensitisation to Aspergillus would be ideal for quickly screening patients with poorly controlled asthma. We will screen patients with uncontrolled asthma in Indonesia with the POC test and compare with the standard-of-care blood test. This will help provide an estimate of the rate of ABPA in Indonesia for the first time, and validate the use of this POC test for use in the screening of ABPA.

Technical Summary

Diagnosis of chronic and allergic forms of Aspergillosis is problematic due the suboptimal performance of diagnostic tests. IgG serology is performed in specialist labs. Fungal culture is insensitive, whereas galactomannan antigen, Aspergillus PCR and Aspergillus serology lack specificity, as they can cross-react with other fungi. Molecular tests are performed in specialised laboratories, are expensive, have long turn around times due to batch testing, and are generally not available in low and middle-income countries (LMIC). POC tests offer a cheaper and more feasible alternative in LMIC and high income settings.
We will assess the performance of POC tests in 3 settings:
Aim 1. A POC Aspergillus IgG test (Aspergillus ICT IgG, LD-Bio) compared with standard-of-care serology testing in patients with presumed smear negative TB in Indonesia. We will enrol patients with presumed smear negative TB according to WHO criteria from 3 respiratory clinics in Indonesia (n=150 over 12 months). We will follow them for 12 months with serial X-Rays and symptom documentation to assess whether positive Aspergillus serology is associated with poor outcomes. We will analyse outcomes separately in patients treated with antifungals.
Aim 2. Two POC Aspergillus antigen tests (IMMY sona Galactomannan LFA and OLM AspLFD) compared with standard of care (fungal culture, Aspergillus PCR, galactomannan) in BAL fluid in patients (n=100 over 12 months) undergoing diagnostic bronchoscopies when aspergillosis is in the differential diagnosis. We will analyse the lung mycobiome as the gold standard. We will record the final diagnosis (chronic pulmonary aspergillosis vs other) and determine the sensitivity, specificity, positive predictive value and negative predictive value of the tests).
Aim 3. Two POC serological tests (Aspergillus IgG and IgE) for screening of patients with uncontrolled asthma in Indonesia (n=100) and in patients with known ABPA in the UK (n=100).

Planned Impact

The following groups will benefit from the proposed research in the following ways:

1. Patients with chronic and allergic aspergillosis

There are multiple anticipated benefits with respect to improving health:
- A greater number of patients in Indonesia and other low and middle income countries (LMIC) with hitherto unrecognised CPA will be diagnosed and treated. There are an anticipated 80000 cases of CPA in Indonesia, most of them unrecognised, and more than 1 million globally as a sequela to TB. Antifungal treatment will improve quality of life in these patients.
- Patients misdiagnosed as presumed TB will be diagnosed as CPA, leading to reduction in use of potentially toxic anti-TB drugs and lowering the rates of antimicrobial resistance by reducing antimicrobial use.
- ABPA will be more readily diagnosed in LMICs, leading to timely antifungal treatment, reduction of steroid use and better control of asthma, avoiding admissions to hospitals and unnecessary antimicrobial use, again limiting antimicrobial resistance. There are more than 13 million asthmatics in Indonesia and the results are applicable to most LMICs.
- Better understanding of Aspergillus diagnostic tests in respiratory secretions in the setting of chronic lung disease will lead to diagnosing or ruling out aspergillosis with more confidence in patients who present with usually present with a very challenging differential diagnosis on a background of often severe lung disease. Differential diagnosis in these patients includes lung cancer or mycobacterial infection, therefore accurate and timely diagnosis will enhance patient experience and prevent unnecessary treatments.

2. Low and middle income countries' health systems

- Adoption of point of care (POC) tests will obviate the need for more expensive tests and the need for access to a specialised laboratory.
- LMICs can divert funds to screening and diagnosis of chronic and allergic aspergillosis. This will be achieved by saving on unnecessary antimicrobial and anti-TB treatment and on the cost of frequent admissions and doctor visits.

3. Researchers in the field of Aspergillosis

-We plan to make our results available for researchers following publication. The proposed research will provide novel data on the dynamics of the mycobiome in chronic lung disease, a topic that has not been investigated in detail previously. The comparison of the mycobiome with our current diagnostic tests in Aspergillosis will provide a gold standard for the evaluation of these tests that has not been used before.

4. Industry

-Proof of the usefulness of POC tests will lead to an increased interest by industry to develop new tests for other fungal infections or other infectious diseases.

Publications

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Description We found that a fungal infection of the lung, chronic pulmonary aspergillosis (CPA), may affect up to one in five adults who have symptoms after successful treatment for tuberculosis in Indonesia. We also showed that a point of care test, a test that is easy to perform outside of a specialist laboratory, is useful in the diagnosis of CPA in resource limited settings.

In this study, we recruited patients who presented with chest symptoms in chest clinics in two cities of Indonesia. The patients had to have a negative test for TB, so that recurrence of TB could be ruled out. Patients who fulfilled criteria for CPA, according to published guidelines, were enrolled. Of these patients, 22% were found to fulfil the criteria. The most common symptom was fatigue, affecting almost half of the patients. Fatigue has been already identified as a main symptom of CPA in the UK. All patients, both those with CPA and those without CPA, provided blood for testing with a point of care test that detects antibodies to the fungus aspergillus. These antibodies are supportive of the diagnosis of CPA. In this patient group, this point of care test was found to be sensitive (80%) and specific (70%).

This was the first study to report on the performance of this test in CPA diagnosis in resource limited settings. the point of care test could be an important addition to the efforts to diagnose CPA following TB globally, as it can be performed at a relatively low cost without the need to a specialised laboratory. As low resource settings often have high TB prevalence , CPA is a big burden to health systems and should be better diagnosed and managed early. Heath authorities in resource limited settings should prioritise the use of rapid diagnostics in CPA. This will lead to faster starting of treatment and better outcomes.
Exploitation Route The performance of rapid diagnostics for CPA should be validated in other countries and in other patient populations, such as in areas with lower TB prevalence, in HIV positive patients, or in patients with COPD, another major risk factor for CPA.

To translate these findings to tangible patient benefit, health authorities should adopt aspergillus testing as a component of TB programmes and include itraconazole and voriconazole (agents used for treatment for CPA) as essential medicines for CPA.

A large scale interventional study on CPA treatment in resource limited settings has never been performed, apart from a small study in India. As a result of the data now available on the use of point of care testing in aspergillosis, this can now be undertaken, as it will simplify the eligibility criteria for participants of such a study, In Indonesia or elsewhere in resourse limited settings.
Sectors Healthcare

 
Description Collaboration between researchers in the University of Manchester and Universitas Indonesia on aspergillosis research 
Organisation Universitas Indonesia
Country Indonesia 
Sector Academic/University 
PI Contribution As part of the MRC Newton Fund on Infection Diseases in UK/Indonesia, we have started the UK part of the research. We have recruited patients with chronic or allergic aspergillosis at the Northwest Lung Centre, Manchester University NHS Foundation Trust. Due to slowing of the recruitment during covid, we do not yet have any results from the UK work. We are testing three point of care tests for the diagnosis of aspergillosis in blood and pulmonary secretions from these patients. A research fellow appointed at the start of the grant is still actively involved, until September 2021. We expect to finish all data collection by September 2021. We (Chris Kosmidis and David Denning) have contributed along with the Indonesian collaborators to a review on chronic pulmonary histoplasmosis which has been published (see publications section). I have contributed to the paper published in Journal of Fungi on the Indonesian side of the work, the assessment of the role of the aspergillus point of care test in the diagnosis of chronic pulmonary aspergillosis (see publications section). Together with the Indonesian colleagues, we delivered a webinar on lung fungal disease, with a focus of chronic aspergillosis on 19 December 2020. It was attended by >500 people, mainly health care professionals from Indonesia. (see engagement activities section).
Collaborator Contribution The collaborators from Universitas Indonesia have recruited more than 250 patients with tuberculosis and performed a point of care test for rapid diagnosis of aspergillosis in blood. They have already followed up to 50 of them after one year. Work on the point of care testing for aspergillosis and the role in diagnosis of chronic pulmonary aspergillosis (the main aim of the collaboration) has been published in Journal of Fungi (see publications section). Another manuscript (on the comparison of this point of care test with another serological test) is being prepared for submission. The collaborators have contributed to a review on chronic pulmonary histoplasmosis which has been published (see publications section).
Impact Two publications: 1. Rozaliyani A, Rosianawati H, Handayani D, Agustin H, Zaini J, Syam R, Adawiyah R, Tugiran M, Setianingrum F, Burhan E, Kosmidis C, Wahyuningsih R. Chronic Pulmonary Aspergillosis in Post Tuberculosis Patients in Indonesia and the Role of LDBio Aspergillus ICT as Part of the Diagnosis Scheme. J Fungi (Basel). 2020 Nov 27;6(4):318. doi: 10.3390/jof6040318. PMID: 33260909; PMCID: PMC7712371. 2. Baker J, Kosmidis C, Rozaliyani A, Wahyuningsih R, Denning DW. Chronic Pulmonary Histoplasmosis-A Scoping Literature Review. Open Forum Infect Dis. 2020 Apr 6;7(5):ofaa119. doi: 10.1093/ofid/ofaa119. PMID: 32411810; PMCID: PMC7210804.
Start Year 2019
 
Description 2nd Pulmonary Mycoses Webinar Series: Chronic Pulmonary Aspergillosis 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact On the 19th December 2020, a webinar was organised by the Indonesia Society of Respirology (ISR) to promote knowledge on chronic pulmonary aspergillosis and to present our research findings to an audience of mainly health care professionals from Indonesia. The event was broadcast live on youtube, and the attendance was estimated to be more than 500. As the event was also advertised in English and several talks were in English, we expect it reached audiences outside Indonesia too.
Among other speakers, Chris Kosmidis spoke about current treatment strategies in chronic pulmonary aspergillosis, David Denning spoke about diagnostic challenges, and Anna Rozaliyani (Indonesia PI for the Newton grant) spoke about our research findings so far on point of care testing in chronic and allergic aspergillosis. The event was attended by the Indonesia's Ministry of Health director for direct infectious diseases who also delivered a talk on the priority of infectious diseases in Indonesia. The event raised awareness of chronic aspergillosis among health care workers in Indonesia.
Year(s) Of Engagement Activity 2020
URL https://www.youtube.com/watch?v=hRViYoKU65Q