Cerebrospinal fluid monocytes in bacterial meningitis, viral meningitis, and neuroborreliosis.

OBJECTIVE

Cerebrospinal fluid (CSF) leukocytes analysis is commonly used to diagnose meningitis and to differentiate bacterial from viral meningitis. Interpreting CSF monocytes can be difficult for physicians, especially in France where lymphocytes and monocytes results are sometimes pooled.

PATIENTS AND

METHODS

We assessed SF monocytes in patients presenting with microbiologically confirmed meningitis (CSF leukocyte count>10/mm3 for adults or >30/mm3 for children<2 months), i.e. bacterial meningitis (BM), viral meningitis (VM), and neuroborreliosis (NB).

RESULTS

Two-hundred patients (82 BM, 86 VM, and 32 NB) were included. The proportions of monocytes were higher in VM (median 8%; range 0-57%) than in BM (median 5%; range 0-60%, P=0.03) or NB (median 5%; range 0-53%, P=0.46), with a high value overlap between conditions.

CONCLUSION

CSF monocytes should not be used to discriminate BM from VM and NB because of value overlaps.