Cryptococcal antigen cross-reactivity is associated with fatal trichosporonosis in patients with hematologic diseases.

Purpose: Invasive trichosporonosis is an emerging, life-threatening fungal infection in immunocompromised patients with hematologic diseases. The lack of reliable diagnostic biomarkers makes early diagnosis challenging, hindering prompt and effective management.

Methods: We conducted a retrospective single-center study of 88 patients with positive Trichosporon cultures, identified from a cohort of 6,169 inpatients with hematologic diseases at a tertiary medical center from 2004 to 2023. Trichosporon species were identified using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF). We investigated the risk factors, clinical characteristics, and outcomes of invasive trichosporonosis in the patient population.

Results: Prolonged corticosteroid treatment and broad-spectrum antibiotic use were associated with an increased risk of developing invasive trichosporonosis. Invasive trichosporonosis presented as a breakthrough infection in 58.5% of cases, predominantly during echinocandin therapy. Second-generation triazole therapy, particularly voriconazole, was associated with improved outcomes. Cryptococcal antigen cross-reactivity was significantly associated with fatal outcomes in our cohort.

Conclusion: Invasive trichosporonosis frequently manifests as a breakthrough infection during echinocandin therapy, often leading to fatal outcomes in hematologic patients. Early initiation of second-generation triazole therapy is crucial. Cryptococcal antigen cross-reactivity may be a useful diagnostic tool, as well as a prognostic marker, in invasive trichosporonosis. Although this cross-reactivity poses diagnostic challenges if misinterpreted, it offers an opportunity for early diagnosis and prompt initiation of appropriate antifungal therapy.