Cerebrospinal fluid and serum lysozyme activity in bacterial and viral meningitis.

Cerebrospinal fluid (CSF) and serum lysozyme concentrations were determined in infants and children with and without acute infectious disease of the central nervous system. Serum lysozyme values from patients with bacterial and viral meningitis were found within the normal range. Lysozyme activity was absent or very low (below 0.5 microgram/ml) in normal CSF. High levels (4-12 microgram/ml) in patients with viral meningitis. A decrease of the lysozyme activity coincided with the clinical improvement of the bacterial meningitis. The lysozyme activity in CSF should be of significant value in detecting an inflammatory disease of the central nervous system.