2567. Diagnosis of Invasive Aspergillosis in Hematological Malignancy Patients Receiving Mold-Active Antifungals: Performance of Interleukin-6 and -8, Asp LFD, and Aspergillus PCR in Same-day Blood and Bronchoalveolar Lavage Fluid Samples

BACKGROUND: Aspergillus spp. induce elevated levels of several cytokines, including Interleukin (IL)-6 and IL-8. It remains unknown whether these cytokines hold value for clinical routine and enhance diagnostic performances of established and novel biomarkers/molecular tests for invasive aspergillosis (IA) in patients receiving mold-active antifungals. METHODS: This cohort study included 106 prospectively enrolled (2014–2017) adult cases with underlying hematological malignancies and suspected pulmonary infection undergoing bronchoscopy. Serum samples were collected within 24 hours of bronchoalveolar lavage fluid (BALF) sampling. Both serum and BALF samples were used to evaluate diagnostic performances of the Aspergillus-specific lateral-flow device test (LFD), Aspergillus PCR, galactomannan, β-d-glucan, and cytokines that have shown significant associations with IA in our previous matched case–control analysis (including IL-6 and IL-8), for IA classified according to the revised EORTC/MSG criteria. RESULTS: Among the 106 cases, 11 had probable IA, 32 possible IA, and 63 no evidence for IA; 80% received mold-active antifungals at the time of sampling. Diagnostic tests and biomarkers showed significantly better performance in BALF compared with blood, with the exception of serum IL-8 which was highly specific for IA and proved to be the most reliable blood biomarkers. Combinations of serum IL-8 with either BALF LFD (sensitivity 100%, specificity 94%) or BALF PCR (sensitivity 91%, specificity 97%) were highly sensitive and specific for differentiating probable IA from no IA. CONCLUSION: High serum IL-8 levels were highly specific, and when combined with either the BALF Aspergillus-specific LFD, or BALF Aspergillus PCR also highly sensitive for diagnosis of IA. [Image: see text] DISCLOSURES: G. Johnson, OLM Diagnostics: Employee, Salary.