Cerebrospinal fluid lens-free microscopy: a new tool for the laboratory diagnosis of meningitis

Robin Delacroix , Sophie Nhu An Morel , Lionel Hervé (1) , Thomas Bordy (2, 3) , Jean-Marc Dinten (2) , Michel Drancourt (4) , Cédric Allier (2, 3)

1 LISA - Laboratoire Imagerie et Systèmes d'Acquisition
2 CEA-LETI - Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information
3 UGA [2016-2019] - Université Grenoble Alpes [2016-2019]
4 URMITE - Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes

Cerebrospinal fluid cytology is performed by operator-dependant light microscopy as part of the routine laboratory work-flow diagnosis of meningitis. We evaluated operator-independent lens-free microscopy numeration of erythrocytes and leukocytes for the cytological diagnosis of meningitis. In a first step, prospective optical microscopy counts of leukocytes done by five different operators yielded an overall 16.7% misclassification of 72 cerebrospinal fluid specimens in meningitis/non-meningitis categories using a 10 leukocyte/mu L cut-off. In a second step, the lens-free microscopy algorithm adapted for counting cerebrospinal fluid cells and discriminating leukocytes from erythrocytes was modified step-by-step in the prospective analysis of 215 cerebrospinal fluid specimens. The definite algorithm yielded a 100% sensitivity and a 86% specificity compared to confirmed diagnostics. In a third step, a blind lens-free microscopic analysis of 116 cerebrospinal fluid specimens, including six cases of microbiology-confirmed infectious meningitis, yielded a 100% sensitivity and a 79% specificity. Adapted lens-free microscopy is thus emerging as an operator-independent technique for the rapid numeration of leukocytes and erythrocytes in cerebrospinal fluid. In particular, this technique is well suited to the rapid diagnosis of meningitis at point-of-care laboratories.

Domaines: Maladies infectieuses

Robin Delacroix, Sophie Nhu An Morel, Lionel Hervé, Thomas Bordy, Jean-Marc Dinten, et al.. Cerebrospinal fluid lens-free microscopy: a new tool for the laboratory diagnosis of meningitis. Scientific Reports, 2017, 7, ⟨10.1038/srep39893⟩. ⟨hal-01489496⟩