Cerebrospinal fluid and neutrophil respiratory burst after subarachnoid hemorrhage.

OBJECTIVES

To investigate the effect of cerebrospinal fluid (CSF) from patients with subarachnoid hemorrhage (SAH) on the activation of polymorphonuclear neutrophils (PMN) in response to receptor-dependent stimulation with N-formyl-l-methionyl-l-leucyl-l-phenylalanine and TNFalpha or non-receptor-dependent stimulation with phorbol 12-myristate 13-acetate.

METHODS

CSF from 12 patients with SAH due to ruptured cerebral aneurysm was collected. Samples of CSF were drawn at different time points. CSF from 6 healthy subjects receiving spinal anesthesia served as the control group. After stimulation of PMN the generation of reactive oxygen intermediates was analyzed on a flow cytometer.

RESULTS

In the presence of CSF, PMN showed a significant suppression of the oxidative burst following stimulation compared to stimulation without CSF. The reduction of the oxidative burst following stimulation was higher in the presence of CSF from patients with SAH. After pretreatment at 56 degrees C, the extent of the suppression observed following receptor-dependent stimulation and CSF from patients with SAH was similar to that seen after stimulation with CSF from healthy individuals.

CONCLUSIONS

These data show that the presence of CSF resulted in a suppression of neutrophil oxidative function. A more distinct depression was seen in the presence of CSF from patients with SAH. We suggest a complex physiological inhibitory and protective mechanism against unfavorable activation of PMN by CSF.