Abstract
Background
IPA causes high morbidity and mortality in immunocompromised patients, but diagnosis remains challenging. A newly formatted AspLFD targets specific Aspergillus antigen JF5, but reported results for this test are variable. We evaluated the performance characteristics of this new AspLFD in BAL fluid of patients with IPA.
Methods
Samples tested were from patients with classic risk factors for IPA defined by EORTC/MSG criteria and that had been prospectively banked in our BAL repository. Each case of IPA identified was matched to two high-risk control patientst without IPA or other invasive fungal infection. Samples were thawed, vortexed, centrifuged, and 100 μL of supernatant was applied to the AspLFD. Results were interpreted at 15 minutes as +, ++, +++, or negative by three independent, blinded observers. Test characteristics, including sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated.
Results
Samples from 14 patients with proven/probable IPA by EORTC/MSG criteria and 28 control patients without IPA were tested. Median age was 58 (range 22–87); 28 were men. Age and gender distribution were similar between cases and controls. Among IPA cases, 9 were on T cell depleting agents, 4 on high-dose steroids, and 3 had prolonged neutropenia. Among non-IPA controls, risk factors were T-cell depleting agents (17), high-dose steroids (11), and stem cell transplant (2). Of the 14 patients with IPA, AspLFD was positive in 3, negative in 9; in 2, the internal control line did not display and these were considered invalid. Of 6 patients receiving an azole, three had a positive AspLFD test. AspLFD was negative for all 28 BAL in the non-IPA group. AspLFD showed low sensitivity (25%) and high specificity (100%); PPV was 100% and NPV was 75%. Accuracy of the test was 77.5%.
Conclusion
A positive AspLFD test in BAL of patients with classic risk factors for IPA could be useful for ruling in proven/probable IPA because of its high specificity. However, the use of AspLFD as a screening test for IPA is limited by its poor sensitivity.
Disclosures
All authors: No reported disclosures.
Session: 230. Diagnostics: Mycology
Saturday, October 6, 2018: 12:30 PM