Elevated production of radical oxygen species by polymorphonuclear neutrophils in cerebrospinal fluid infection

This study included 30 patients with suspected CSF infection with ventricular hemorrhage requiring external ventricular drainage, and 13 patients after trauma or surgery. Criteria for evaluating CSF infection included positive culture and > 100 leukocytes/mm3. Analysis of PMN phenotype was performed using flow cytometry (CD16, CD11b, and CD62L). ROS production was analyzed through luminometry (luminol).Infected CSF exhibited higher production of ROS compared with noninfected CSF. PMNs in CSF exhibited low CD16 and high annexin V expression, suggesting apoptosis.Measurement of ROS production may discriminate infected from noninfected CSF. This simple test would be easy to employ in clinical practice to improve CSF infection management.Diagnosis of meningeal or intracranial infection remains difficult in post-trauma or neurosurgical patients for several reasons. Clinical symptoms often are mild and nonspecific and sometimes are masked by corticoids or therapeutic hypothermia. Additionally, classical criteria based on cerebrospinal fluid (CSF) analysis, such as pleocytosis with a high proportion of polymorphonuclear neutrophils (PMNs), low glucose, and high protein levels, are difficult to interpret soon after bleeding or surgical procedures. Finally, direct bacteriological examination results may be negative because of concomitant antibiotic therapy for another treated infection [1]. Because such infections can have a major impact on patient evolution and be detrimental to prognosis, clinicians have no choice but to perform repeated CSF analyses and to administer broad-spectrum antibiotics for at least 48 to 72 h while awaiting validation by microbial cultures. Such risk-based care leads to repeated CSF checking and promotes the selection of antibiotic-resistant organisms [2]. A rapid, specific, sensitive test with which to diagnose CSF infection could streamline therapeutic decisions in clinical practice.Ventriculostomy catheterization, or external ventricular draina