INCREASED ACTIVITY OF LYSOSOMAL ACID-HYDROLASES IN THE CELL-FREE CEREBROSPINAL-FLUID OF BACTERIAL-MENINGITIS

Because inflammation could affect lysosomal enzyme trafficking, result ing in increased enzyme release from the cells, tissue necrosis, or al tered blood- and the brain-cerebrospinal fluid (CSF) barrier, the acti vity of four lysosomal enzymes in the cell-free CSF of 34 patients wit h bacterial meningitis, 20 with aseptic meningitis, and 39 control sub jects was measured. Activities are expressed in nanomoles of 4-methylu mbelliferone/mL/h. The median beta-hexosaminidase A activity in bacter ial meningitis was 313, in aseptic meningitis it was 173, and in the c ontrol subjects it was 175; the median beta-hexosaminidase B activity was 417, 165, and 120; the median alpha-mannosidase activity was 171, 124, and 113, and the median beta-glucuronidase activity was 133.7, 14 .3, and 10.0, respectively. The difference of the activities of the fo ur enzymes measured between the bacterial meningitis and the controls is significant (p < 0.000). Also, significant is the difference betwee n bacterial and aseptic meningitis (p = 0.005 to <0.000), but it is no t significant between aseptic and control subjects. Both the sensitivi ty and specificity of the beta-glucuronidase activity between bacteria l meningitis and control subjects were 100%, whereas the corresponding values between bacterial and aseptic meningitis were 100% and 90%, re spectively. No significant correlation was observed between the activi ties of the enzymes measured and the number of the polymorphonuclear l eukocytes or other laboratory characteristics of the CSF. The increase d lysosomal enzyme activities in the CSF of patients with meningitis m ay result from diffusion across the blood-CSF or the brain-CSF barrier or from enzyme leakage through the cell membranes.