This article is more than 5 years old. Information may no longer be current.
Breath test identified metabolites associated with fungal pneumonia
DENVER — A new diagnostic method using a breath test that detected specific metabolites accurately identified patients with pneumonia caused invasive fungal disease, according to data presented at the 2013 Interscience Conference on Antimicrobial Agents and Chemotherapy.
The test had 93% sensitivity and 96% specificity among a set of 54 cancer and transplant patients who had suspected fungal pneumonia, according to Sophia Koo, MD, of the division of infectious diseases at Brigham and Women’s Hospital.
Sophia Koo
“There is an urgent need for better diagnostic tests for invasive aspergillosis, an infection that commonly develops in patients with compromised immunity,” Koo told Infectious Disease News. “Existing diagnostic tests have significant limitations in their sensitivity and specificity, and the turnaround time of these tests is often at least a few days.”
Koo and colleagues collected tidal breath from 54 patients with suspected invasive fungal disease and concurrent ambient air control samples to analyze for volatile organic compounds using gas chromatography-mass spectrometry. Demographic characteristics and risk factors for invasive fungal disease were similar between the 29 patients who had confirmed invasive aspergillosis and the 25 who had pneumonia of other causes.
Among the 29 patients with aspergillosis, the volatile organic compound combination of sesquiterpenes fernesene, beta-vatirenene and the oxidized farnsene derivative cis-geranylacetone correctly identified 27 of the 29 patients with invasive aspergillosis and 24 of the 25 patients without it. The overall diagnostic accuracy was 94%.
“Since these infections are often rapidly progressive and potentially fatal if not treated early, clinicians often administer costly and potentially toxic antifungal therapy empirically to patients with suspected fungal pneumonia, although many of these pneumonias are actually caused by other infectious or inflammatory processes,” Koo said. “We need more accurate, rapid tests to help us distinguish aspergillosis from these other conditions so that we can better determine which patients should receive antifungal therapy.”
Koo said that she hopes this test can be adapted to a rapid, noninvasive, bedside detection system for real-time surveillance of aspergillosis and other fungal diseases in immunocompromised patients. Her team is also exploring volatile metabolic profile of other fungal and bacterial species, both in vitro and in the breath of patients with pneumonia.
For more information:
Koo S. #M-219. Presented at: ICAAC 2013. Sept. 10-13, 2013; Denver.
Sophia Koo MD, can be reached at: Division of Infectious Diseases, Brigham and Women’s Hospital, 75 Francis Street, PBB-A4, Boston, MA 02115; email: skoo1@partners.org.
Disclosure: Koo reports no relevant financial disclosures.