Several false positive low serum cryptococcal antigen (SCrAg) reports by lateral flow assay (LFA) were identified in late 2016 at our tertiary care hospital. After the recall and correction of the problem in the reagent, we studied the significance of SCrAg LFA ≤ 1:10 from January 2017 to October 2023. Of 20 patients with 31 samples of SCrAg LFA ≤ 1:10, 14 patients (70%) were classified as true positives, four (20%) were indeterminate, and only two (10%) patients were false positives. If a new SCrAg LFA ≤ 1:10 is detected, it should be repeated, and additional workup should be pursued.
Keywords: false positive; lateral flow assay; low titer; serum cryptococcal antigen.
We studied the significance of low serum cryptococcal antigen (SCrAg) titer lateral flow assay (LFA) ≤ 1:10 from January 2017 to October 2023. Of 20 patients with SCrAg LFA ≤ 1:10, only two patients (10%) were false positives. If a new SCrAg ≤ 1:10 is detected, it should be repeated, and additional workup should be done.
© The Author(s) 2024. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology.