Cyclic adenosine-3',5-monophosphate concentration and enzyme activities of cerebrospinal fluid in meningitis of children.

The concentration of cyclic adenosine-3',5'-monophosphate (cAMP) and the activities of some enzymes of 29 children were measured from cerebrospinal fluid (CSF) and plasma at various stages of meningitis. The CSF cAMP values in acute untreated phase of aseptic and purulent meningitis were equal, but significantly higher than those of convalescent children with no pathological clinical or laboratory findings. During the whole course (up to 2 weeks) of antimicrobial treatment of the purulent meningitis CSF cAMP concentration was higher than in the convalescent phase. Of the CSF enzymes studied, the lactic dehydrogenase activity seemed to be the best indicator of changing stages of meningitis. It was clearly elevated in the acute, untreated phase of purulent meningitis then decreasing during the course of treatment. In aseptic meningitis this activity was at the normal level and the activities of creatine kinase and acid phosphatase behaved similarly. The plasma cAMP concentrations in the acute phase of purulent meningitis were in the same range as in the CSF. During the treatment no significant changes were seen. The enzyme activities in the plasma were normal. The CSF cAMP level seems to be a sensitive indicator of metabolic disturbances in meningitis and may serve as a diagnostic aid.