Detection and significance of blood neutrophil CD64 expression as a diagnostic marker in bacterial meningitis in children.

Appropriate, rapid and reliable laboratory tests are essential for the diagnosis and therapy of acute bacterial meningitis especially in children. The purpose of this study was to evaluate the diagnostic value of flowcytometric detection of CD64 surface marker on blood neutrophils in diagnosis of acute bacterial meningitis. Our work included 132 (74 males and 58 females) patients with suspected meningitis, whose ages ranged from 2 months to 11 year. Patients were subjected to full clinical examination, complete blood count (CBC), cerebrospinal fluid (CSF) chemical and bacteriological analysis and detection of CD64 surface marker on blood neutrophils (CD64+ leucocytes). Based on the microbial culture results, patients were classified into bacterial meningitis group I (44) and non bacterial meningitis group II (88). The most prevalent isolates were Streptococcus pneumoniae (23) followed by H. influenzae (9) and N. meningitidis (6). Flowcytometry results indicated that the mean percentage of neutrophil CD64+ expression in bacterial meningitis (71.38 +/- 7.11) was significantly higher compared to culture negative meningitis (48.63 +/- 14.55) and controls (4.37 +/- 13.5). Flowcytometric assessment of neutrophil CD64 expression could serve as a reliable laboratory tool for detection of bacterial meningitis and may be a useful adjunct in differentiating bacterial and non bacterial meningitis.