In healthy humans, Lysozyme is present in all except:
Lysozyme is an enzyme that acts on the peptidoglycan layer of the bacterial cell wall and destroys it, which results in the leakage of contents from the cells and leads to cell death. It forms the first line of defence. Cerebrospinal fluid (CSF) is usually devoid of lysozyme in normal healthy children but in the case of inflammatory disease involving the central nervous system, lysozyme can be found in CSF. The highest titers (a measurement of the amount or concentration of a substance in a solution) of lysozyme in CSF are found in patients with purulent bacterial meningitis.
Lacrimal secretions, saliva and respiratory tract secretions contain lysozyme as they are the physiological barriers of the first line of defence.