Cerebrospinal fluid neopterin analysis in neuropediatric patients: establishment of a new cut off-value for the identification of inflammatory-immune mediated processes.

OBJECTIVE: A high level of cerebrospinal fluid (CSF) neopterin is a marker of central nervous system inflammatory-immune mediated processes. We aimed to assess data from 606 neuropediatric patients, describing the clinical and biochemical features of those neurological disorders presenting CSF neopterin values above a new cut-off value that was defined in our laboratory. METHODS: To establish the new CSF neopterin cut-off value, we studied two groups of patients: Group 1 comprised 68 patients with meningoencephalitis, and Group 2 comprised 52 children with a confirmed peripheral infection and no central nervous system involvement. We studied 606 CSF samples from neuropediatric patients who were classified into 3 groups: genetic diagnosis (A), acquired/unknown etiologic neurologic diseases (B) and inflammatory-immune mediated processes (C). RESULTS: The CSF neopterin cut-off value was 61 nmol/L. Out of 606 cases, 56 presented a CSF neopterin level above this value. Group C had significantly higher CSF neopterin, protein and leukocyte values than the other groups. Sixteen of twenty-three patients in this group had a CSF neopterin level above the cut-off, whereas three and seven patients presented increased leukocyte and protein values, respectively. A significant association was found among CSF neopterin, proteins and leukocytes in the 606 patients. White matter disturbances were associated with high CSF neopterin concentrations. CONCLUSIONS: Although children with inflammatory-immune mediated processes presented higher CSF neopterin values, patients with other neurological disorders also showed increased CSF neopterin concentrations. These results stress the importance of CSF neopterin analysis for the identification of inflammatory-immune mediated processes.

Human Metapneumovirus in the Cerebrospinal Fluid of a Patient With Acute Encephalitis.

OBJECTIVE: To report, to our knowledge, the first case of detection of human metapneumovirus in the cerebrospinal fluid of a patient during acute encephalitis. DESIGN: Case report. SETTING: University hospital. PATIENT: A 10-year-old girl with acute encephalitis. RESULTS: Human metapneumovirus was detected in cerebrospinal fluid and nasal-wash specimens during the initial phase of mild encephalitis. Abrupt clinical deterioration was associated with the presence of multiple areas of demyelination and cortical abnormalities. Demyelinated areas improved after immunomodulatory therapy, but cortical lesions spread in both hemispheres. Surprisingly, clinical worsening occurred when the virus became undetectable in cerebrospinal fluid. CONCLUSIONS: The detection of human metapneumovirus in cerebrospinal fluid strongly suggests its causative role in acute encephalitis. The evolution of the clinical and radiological features provided insight into the pathogenesis of human metapneumovirus encephalitis.