Serum Substance P Concentration in Children With Traumatic Brain Injury: A First Report

To review the clinic value and severity assessment of serum substance P (SP) concentration in children with different degrees of traumatic brain injury (TBI) through analyzing correlations with outcomes.One hundred thirty-nine children with TBI who were diagnosed and treated at Nanjing Medical University for longer than 72 hours between June 2017 and 2019 were analyzed. Blood samples were obtained within 24 hours after TBI to measure SP concentration. The endpoint was discharge mortality. Thirty healthy children composed the control group. Comparative analyses of differences in SP concentration were conducted for the different groups. Both the Sequential Organ Failure Assessment (SOFA) scores and Pediatric Clinical Illness Score (PCIS) were measured on admission and used in univariate and multivariate analyses.The serum SP (89.10 ± 64.32) pmol/L) level in the case group was significantly higher than that in the control group (21.84 ± 2.09) pmol/L (t = 5.71, P0.05). The serum SP (182.81 ± 58.39) pmol/L) level in the deceased group was significantly higher than that in the survival group (59.93 ± 27.90) pmol/L (t = 16.52, P0.05). A negative correlation existed between serum SP concentration and Glasgow Coma Scale score in the severe, moderate, and mild groups (r = -0.72, P0.05). Serum SP concentration was identified as an independent risk factor for mortality (odds ratio1, 95% confidence interval = 1.04-1.28, P0.01). Receiver operating characteristic curve analysis suggested that serum SP concentration had the same calibrating power as SOFA and PCIS in discriminating the risk of death of children.Serum SP concentration was associated with severity in children with TBI, and extremely high levels indicated a poor prognosis.