The current study was carried out on sixty two carbon monoxide (CO) poisoned patients admitted to
Poison Control Center Ain Shams University (PCCA), from January 2008 to June 2009. Patients were divided
into four groups: Group I: twenty patients (mild CO poisoning). Group II: fifteen patients (moderate
CO poisoning). Group III: twenty seven patients (severe CO poisoning). Group IV (control): fifteen
healthy non-smokers. Serum S100B protein, blood CO level, random blood sugar (RBS) and arterial
blood PH were assessed in all groups. Highly significant increase in serum S100B protein was found in
all studied patients in comparison with the control. Patients who developped neurological sequelae had
significantly high S100B protein. Blood CO level was significantly high in all tested groups. There was
also highly significant increase in RBS in group III only. In addition, there was significant increase in the
RBS in patients who died and in those with neurological sequelae. It can be concluded that protein S100B
may be used as a useful biomarker of brain damage in acute CO poisoning and is helpful in assessment of
its severity and prediction of neurological sequelae and mortality.