Increased serum S100B levels constitute a valid predictor of unfavourable outcome in severe TBI, regardless of the presence of associated multitrauma.

Severe traumatic brain injury (TBI) is associated with a 35-70% mortality rate. Biochemical markers of cellular stress/injury have been proposed to indicate outcome after head injury. Therefore, our aim was to determine whether Hsp70 could be detected in the serum of patients after severe TBI and whether serum levels of Hsp70 correlate with primary outcome in severe TBI. Twenty consecutive male patients, victims of severe TBI (GCS 3-8), were enrolled in this prospective study. Clinical outcome variables of severe TBI comprised: survival, time for ICU discharge, and neurological assessment using the Glasgow Outcome Scale (GOS) at the ICU discharge. Venous blood samples were taken at admission in the ICU (study entry), 24 h later, and 7 days later. A control group consisting of eight healthy male volunteers was also included. Serum Hsp70 levels were measured by an enzyme-linked immunosorbent assay. Mean serum Hsp70 concentrations were significantly increased in the TBI (97.6, 48.1, and 39.2 ng/mL, at study entry, 24 h later, and 7 days later, respectively) compared with the control group (12.2 ng/mL). Severe TBI was associated with a 50% mortality rate. On study entry (mean time 10.8 h after injury), a higher proportion of patients with fatal outcome had elevated serum Hsp70 (mean 143.5 ng/mL) concentrations when compared with survivors (mean 51.6 ng/mL). There was a significant correlation between higher initial serum Hsp70 concentrations and fatal outcome. The sensitivity of serum Hsp70 predicting mortality according to the cutoff of 62 ng/mL is 70% within 20 h after injury. Increased serum Hsp70 levels may constitute an early predictor of unfavorable outcome in severe TBI in males.

The prediction of outcome is one of the major problems associated with traumatic brain injury. Recently, investigations have been performed on the potential use of circulating cell-free DNA in plasma for clinical diagnosis and prognosis of a variety of conditions. In this study, we investigated DNA plasma concentrations after severe traumatic brain injury (TBI) and its correlation with primary outcome. We studied 41 male victims of TBI, with isolated severe TBI or severe TBI with associated exracranial injuries. Control samples were obtained from 13 healthy male volunteers. Plasma DNA was measured by a real-time PCR assay for the beta-globin gene. The mean time for first sampling (study entry) was 11.7 +/- 5.2 h after injury; subsequent DNA determinations were performed 24 h after study entry. Mean plasma DNA concentrations were significantly increased in TBI patients (366,485 and 131,708 kilogenomes-equivalents/L, at study entry and 24 h later, respectively) compared with the control group (3031 kilogenomes-equivalents/L). Additionally, a significant correlation between higher plasma DNA concentrations, determined 24 h after study entry, and fatal outcome was observed. However, at second sampling, there was no significant correlation between plasma DNA concentrations and the presence of associated extracranial injuries. High plasma DNA concentrations at second sampling time predicted fatal outcome with a sensitivity of 67% and specificity of 76%, considering a cut-off value of 77,883 kilogenomes-equivalents/L. Thus, this study showed that severe TBI is associated with elevated DNA plasma levels and suggests that persistent DNA elevations correlate with mortality.

These data suggest that 5-FU induced Hsp70 synthesis in the HT-29 resistant cell line and that this Hsp70 accumulation could protect against 5-FU-induced apoptosis. Thus, Hsp70 protection against 5-FU-induced apoptosis might underlie colon cancer chemoresistance.

Increased serum sFas and TNFalpha levels following isolated severe TBI did not predict fatal outcome.