Plasma IP-10 as a Predictor of Serious Bacterial Infection in Infants Less than 4 Months of Age

Abstract

Early diagnosis of serious bacterial infection (SBI) in young infants is a difficult problem by clinical symptoms and signs. The goal of this study is to evaluate the predictive value of plasma IP-10 levels for early diagnosis of SBI in young infants <4 months of age. We enrolled pediatric patients who were <4 months of age with a clinical suspicion to have SBI admitted in neonatal intensive care unit or complete nursing unit of Pediatric Department of Kaohsiung Medical University Hospital. Blood was drawn for measurement of complete blood counts, C-reactive protein (CRP) and plasma IP-10 levels and microbiological cultures were obtained at the time of admission. There were 60 patients enrolled in this study. The SBI group (n = 21) have higher plasma IP-10 levels than those infants without SBI (n = 39) [median 104.8 (range 0-1457.1) versus 0 (range 0-129.3) ng ml(-1), P = 0.0161 after adjusting age]. A plasma IP-10 level >48.2 ng ml(-1) had the best diagnostic accuracy for indicating SBI [sensitivity 81.0% [95% confidence interval (CI) 71.1-90.1%]; specificity 94.9% [95% CI 65.4-87.0%]; positive likelihood ratio 15.9, negative likelihood ratio 0.2}. In infants who were <4 months of age with suspicion of SBI, IP-10 assay might be a good predictor.