Flow Cytometry To Assess Cerebrospinal Fluid Fungal Burden in Cryptococcal Meningitis

Abstract

Fungal burden in the cerebrospinal fluid is an important determinant of mortality in cryptococcal meningitis, but its use in aiding clinical decision making is hampered by the time involved to perform quantitative cultures. Here, we demonstrate the potential of flow cytometry as a novel and rapid technique to address this issue.

FIG 1

CSF flow cytometry gating CSF cells (forward scatter [FSC] and side scatter [SCC]), showing a poor definition of cell subsets due to cryptococci (a1), CD45 and LIVE/DEAD stain are used to separate cells (a2), FSC-SSC plot of cryptococci (b), FSC-SSC plot of CSF leukocytes (c), and FSC-SSC plot of dead CD45⁺ cells.

FIG 2

(a) Scatterplot demonstrating association between flow cytometry counting, and quantitative culture. (b) Bland-Altman plot showing good agreement between flow counting and quantitative culture (gray area indicates the 95% limits of agreement). (c) Association between flow counting and quantitative culture among participants who had not received antifungal therapy before CSF sampling. (d) Bland-Altman plot showing agreement between the two techniques, limited to participants who had not received antifungal therapy before CSF sampling (gray area indicates the 95% limits of agreement).