Abstract
OBJECTIVE
To determine the diagnostic accuracy of Glow Aspergillus Galactomannan Ag™ LFA for detection of galactomannan in serum samples keeping Platelia™ Aspergillus Ag ELISA as the reference standard.
STUDY DESIGN
Cross Sectional Study
PLACE AND DURATION OF STUDY
This study was conducted at the Department of microbiology, Armed Forces Institute of Pathology (AFIP), Rawalpindi from 17 December 2024 to 17 June 2025.
METHODOLOGY
A total of 155 Serum samples received in the microbiology laboratory for galactomannan antigen testing were included in the study. All serum samples were tested with two assays, including Glow Aspergillus Galactomannan Ag™ LFA and Platelia™ Aspergillus Ag. The samples were tested simultaneously under standardized protocols as defined in the literature provided by the manufacturer. Data was entered and analyzed using SPSS version 27. Frequencies and percentages were calculated for qualitative variables. The analysis assessed sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall accuracy. The agreement between the test results was measured using the Kappa coefficient.
RESULTS
Out of 155 samples, 20 (12.9%) tested positive on LFA, while 18 (11.6%) tested positive on ELISA. The LFA correctly identified 14 true positives and 113 true negatives, with 4 false negatives and 24 false positives.
The diagnostic performance of the LFA demonstrated a sensitivity of 77.8%, specificity of 82.5%, PPV of 36.8%, NPV of 96.6%, and an overall diagnostic accuracy of 81.9% when compared to ELISA.
CONCLUSION
The Glow Aspergillus Galactomannan Ag™ LFA demonstrated moderate sensitivity and specificity with a high negative predictive value (96.6%), indicating that it is best suited as a rule-out test for galactomannan antigenemia. While the assay offers a rapid screening advantage, its relatively lower positive predictive value necessitates confirmation of positive results by ELISA before clinical decision-making.
Suggestion given was: In the conclusion of the abstract, explicitly state that the LFA is best used as a "rule-out" test due to the high NPV (96.6%), rather than just saying "useful rapid screening tool".