The accuracy of cerebrospinal fluid and serum S100B protein to diagnose bacterial meningitis in children at pediatric ward Department of child's Health Sanglah Hospital Denpasar Bali

Background: The diagnosis of bacterial meningitis is challenging because of the vague clinical presentation primarily in infants and children. The S100B protein is a biomarker of the inflammatory process in the brain. It is thought to have a relationship with neuron damage and oxidative stress in bacterial meningitis. Methods: In this study, we measured the levels of S100B protein in cerebrospinal fluid (CSF) and serum by using ELISA method, in children with suspected bacterial meningitis. The diagnosis of proven bacterial meningitis is based on a positive culture that confirmed the causing bacteria. We analyzed the data by using MedCalc-version 17.6 programme. Results: Eighty patients suspected of bacterial meningitis included in this study. As many as 47 (58.8%) are males. The mean of age was 29.8 months (SD ± 32.1). Prevalence of proven bacterial meningitis was 21 out of 80 (26.25%). The primary clinical symptoms were seizures, decreased consciousness, clinically sepsis, positive meningeal sign, vomiting and focal neurologic deficits. The comparison of CSF S100B levels between a positive culture and negative culture were 31.4 (SD ± 32.81) and 29.2 (SD ± 27.13). The serum S100B level in a positive culture was 114.1 (SD ± 95.67) and in a negative culture was 74.9 (SD ± 75.84). The area under the curve (AUC) of CSF S100B and serum S100B were 0.523 and 0.655, respectively. For diagnosing bacterial meningitis, the optimal level of CSF S100B protein is ? 54 ng/L (sensitivity 29%, specificity 98%), while the optimal level of serum S100B is ? 177 ng/L (sensitivity 19%, specificity 98%). Conclusion: CSF S100B and serum S100B protein have prospective value with high specificity to confirm the diagnosis of bacterial meningitis in children. Serum S100B may be used as an additional test for diagnosing bacterial meningitis in children when there is a contraindication for lumbar puncture.