LOS ANGELES — Antifungal therapy relieves symptoms in patients with severe asthma, chronic sinusitis, or both whose sputum tests positive for fungal cultures, new research shows.
The approach even worked in patients who weren't particularly sensitive or allergic to fungi, said Evan Li, MD, a resident at the Baylor College of Medicine in Houston.
Previous studies of antifungal therapy in patients with asthma and chronic sinusitis have produced mixed results, Dr Li explained during a poster session here at the American Academy of Allergy, Asthma and Immunology 2016 Annual Meeting.
But the study by Dr Li and his colleagues differed from previous studies in a number of ways. They used a more reliable method of fungal culture, which allowed for the careful selection of patients. And patients were treated more aggressively. About two-thirds required more than one course of the 3-month treatment regimen to achieve improvement.
The retrospective analysis involved 134 patients treated at the Michael E. DeBakey VA Medical Center in Houston from 2012 to 2015. All had been referred to the allergy clinic because of uncontrolled asthma, and all provided sputum samples that were tested for fungi.
Method of Fungal Culture "Critical"
The method of fungal culture is critical, Dr Li explained. Existing methods are unreliable, in part because sputum contains immune cells and antifungal compounds that can impede growth in culture.
His team treated the sputum samples with dithiothreitol (300 mg/mL of sputum) and vortexed and centrifuged them until pellets were produced, which were then resuspended and applied to growth plates.
With this method, "we have probably near 100% specificity and sensitivity," Dr Li reported.
Of the 134 patients, 112 (83.5%) tested positive, defined as the formation of at least six colonies within 2 weeks. Seventy-five were treated with voriconazole, terbinafine, or fluconazole, alone or in combination.
Voriconazole was the drug of choice, but because of its contraindication profile, another drug was often used, Dr Li said.
There was a significant improvement in symptoms in more than 90% of the patients treated with voriconazole and in about half of the patients treated with terbinafine. "Terbinafine is not as effective but it is much safer and a lot easier to tolerate," he told Medscape Medical News.
However, relatively few patients stopped taking voriconazole. "I can probably count them on one hand," Dr Li said.
Follow-up data were available for 62 patients — 23 with asthma, 17 with chronic sinusitis, and 22 with both. They experienced a range of benefits from the antifungal therapy.
Table: Benefits of Antifungal Therapy
Benefit Percent (n = 62)
Subjective benefit 87.1
Less sputum production 50.0
Improved breathing 38.7
Less cough 32.2
Less rescue inhaler use 14.5
A lot of data support the use of antifungal agents, "they just haven't caught on in the asthma and pulmonology community," Dr Li reported.
Other attempts to use antifungal rinses have failed to produce an effect, likely because the patients were not properly selected, said Daniel Hamilos, MD, from Harvard Medical School in Boston.
"To me, that's the extremely critical point," he told Medscape Medical News. "There's really nothing unusual or fancy about the protocol. Any microbiology lab could do it."
Dr Li said his team has no intention of patenting the process.
The next step is to conduct a prospective clinical trial, which the researchers are pursuing through grant proposals and, potentially, an industry partner.
"Once that gets going, I think we'll undoubtedly prove that antifungals are very effective," Dr Li said.