Role of Biomarker (Protein S100β) in Clinical Neurological Assay in Pediatric Patients with Congenital Heart Disease

This chapter aimed to determine whether a correlation exists between S100B serum levels and clinical background variables at the pre-operative period of pediatric patients with congenital heart disease. S100B is a calcium-binding protein, belonging to the S100 family proteins which are characterized by their high solubility and, currently, comprises 21 members which are expressed in a cell-specific manner. S100B protein has been proposed as a brain injury biomarker in several clinical scenarios. We designed a prospective case-control study that included all pediatric patients (one month to 18 years old), with congenital heart disease, admitted at our institution for surgical treatment, in a 3 month period of time.

We studied 44 patients at the pre-operative period and divided them in two groups: 20 with clinical neurological background and 24 without them. Clinical pediatric neurological background variables were obtained, and serum levels of S100B protein were measured using the ELISA “sandwich” technique.

The cut-off for S100B serum level in patients with clinical neurological background variables was 16 pg/ml, with sensibility and specificity values of 70% and 70.8%, respectively. S100B protein levels greater than 16 pg/ ml correlated with clinical neurological background variables (p=0.014, OR=2.556, and 95% CI=1.205 - 5.418). Neurological clinical background variables before operation may modify operative resilience and the risk of neurological complications. S100B protein appears to be the potential biomarker that we are looking for establishing neurological morbidity risk at the preoperative period of surgery for congenital heart disease, due its correlation with clinical neurological background, as shown in this study.

Despite the need of more evidences, our results support a strong trend to consider S100B protein as a potential biomarker of clinical neurological background in pediatric patients with congenital heart disease at the pre-operative period, because its serum levels > 16pg/ml may predict neurological damage at a reliably and costless way before surgery, allowing the clinicians for a more accurate neurological support postoperatively in order to improve results.