Alpha-naphthyl-acetate-esterase activity in cerebrospinal fluid cells.

Mono-histiocytes and T-lymphocytes were assessed by the cytochemical alpha-naphthyl-acetate-esterase (ANAE) stain in 50 CSF samples of patients with various neurological diseases. The ANAE-activity of lymphocytes was decreased in multiple sclerosis and subacute sclerosing panencephalitis, while the activity of mono-histiocytes was increased in the group of infarctions and bacterial and viral infections of the central nervous system. In bacterial meningitis and viral meningo-encephalo-radiculitis the number of ANAE-positive lymphocytes increased after treatment and clinical improvement. ANAE staining appears to be a useful additional tool in CSF cytology in these conditions.