Serum soluble CD40 Ligand levels are associated with severity and mortality of brain trauma injury patients

Background: Serum soluble CD40 Ligand (sCD40L) levels, which exhibit prothrombotic and proinflammatory properties, have not been studied in patients with traumatic brain injury (TBI). Thus, the objective of this study was to determine whether serum sCD40L levels are associated with severity and mortality in patients with severe TBI.

Methods: This was a prospective, observational and multicenter study carried out in six Spanish Intensive Care Units. Patients with severe TBI defined as Glasgow Coma Scale (GCS) lower than 9 were included, while those with Injury Severity Score (ISS) in non-cranial aspects higher than 9 were excluded. Serum levels of sCD40L were measured on the day of TBI. Endpoint was established in 30-day mortality.

Results: We found higher serum sCD40L levels (P<0.001) in non-surviving TBI patients (N=27) than in survivor ones (N=73). Logistic regression analysis showed that serum sCD40L levels were associated with 30-day mortality (OR=1.58; 95% CI=1.12-2.21; P=0.008) controlling for APACHE-II score and computer tomography findings. The area under the curve (AUC) for serum sCD40L levels as predictor of 30-day mortality was 0.79 (95% CI=0.70-0.86; P<0.001). Survival analysis showed that patients with serum sCD40L levels higher than 2.11 ng/mL presented increased 30-day mortality than patients with lower levels (Hazard ratio=9.0; 95% CI=4.25-19.27; P<0.001). We found an association between serum sCD40L levels and APACHE-II (rho=0.33; P=0.001), and GCS score (rho=-0.21; P=0.04).

Conclusions: To our knowledge, this is the first study reporting data on serum sCD40L levels in patients with severe TBI. The most relevant and newer findings of our study are that serum sCD40L levels in non-surviving patients with severe TBI are higher than in surviving ones, and that there are an association between serum sCD40L levels and TBI severity and mortality.