Mycobiome load highest in patients on steroids, antifungal therapy
Fungal microbiome, also called the mycobiome, appears to be highly variable in patients with well-characterized fungal diseases, a recent study has shown. Moreover, severe asthmatics have the highest fungal loads, along with those receiving steroid and antifungal therapy.
The study included 16 patients with allergic bronchopulmonary aspergillosis (ABPA), 16 with severe asthma with fungal sensitization, nine with severe asthma not sensitized to fungi, seven with mild asthma and 10 healthy controls. Real-time polymerase chain reaction (RT-PCR) was performed after bronchoscopy to determine fungal load.
RT-PCR revealed that a large variability in fungal loads across bronchoalveolar lavage samples, with severe asthmatics showing the greatest fungal levels. Healthy individuals all had low fungal burdens high in Basidiomycete DNA.
In cases where fungal loads were much greater than in healthy controls, Aspergillus fumigatus accounted for the additional burden and formed the largest fungal proportion in patients with disease.
Antifungal therapy with itraconazole appeared to have counterintuitive effects on fungal load in the bronchoalveolar lavage samples. Participants who had never taken the medication had comparable fungal loads to those who were currently on antifungal therapy.
In contrast, those who had prior histories of the medication but had stopped showed the highest burden of fungus. This effect was significant only when compared against participants who were currently on medication (p=0.018). The same was true for A. fumigatus load (p=0.03).
Similarly, ABPA patients receiving corticosteroid therapy also had significantly elevated fungal loads relative to participants not on therapy.