P419 Galactomannan enzyme immunoassay in invasive pulmonary aspergillosis: a cross sectional study in 2021 in a New Delhi

POSTER SESSION 3, SEPTEMBER 23, 2022, 12:30 PM - 1:30 PM: OBJECTIVE: This study aims to determine the role of GM EIA in the diagnosis of IPA as per revised EORTC/MSG 2019 criteria. MATERIAL AND METHODS: A prospective cross-sectional study was performed on 87 children (from 1 to 12 years) admitted to pediatric hematology ward from Oct 2020 to February 2022. Serum of these patients was collected and GM EIA was performed using BIO-RAD Platelia™ Aspergillus Ag. Clinical, mycological workup (potassium-hydroxide mount, fungal culture) was done and furthermore, these patients were classified into proven, probable, and possible IA as per EORTC-MSG guidelines, 2019. Galactomannan indices (GMI) measured in terms of sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were validated with revised EORTC -MSG, 2019 of IPA. RESULTS: A total of 53 patients out of 87 were categorized into probable IPA with routine mycological findings. On culture Aspergillus flavus was the most common pathogen, identified in 56% (25), followed by A. fumigatus 31.8% (14), A. niger 9% (4), etc. 44 (50.5%) had GMI value of >0.7, 9 (10.3%) in the range of 0.5-0.7 and 34 (39%) had GMI <0.5. The maximal Youden index ‘J’ [95% confidence interval (CI) of 0.4167-0.6875] was calculated as 0.678 and sensitivity, specificity, PPV, and NPV in IPA were calculated corresponding to a GM index of >1.0, 0.7, 0.5 to determine the best cutoff point. The best cutoff was found to be 0.695 where in the 84.1% and specificity was 83.7% respectively. CONCLUSION: GM EIA can prove as an excellent diagnostic test for IPA when done in addition to culture from nonsterile sites in high-risk populations like pediatric patients with hematological malignancy. This study reinforces the definition of the probable category of EORTC-MSG criteria, 2019 in overall diagnosis, prognosis, and management of IPA in pediatric patients with hematological malignancy.