14-3-3 protein detection in the cerebrospinal fluid of patients with influenza-associated encephalopathy.

Influenza-associated encephalopathy is characterized by high fever, convulsions, and loss of consciousness associated with influenza infection in children, but its pathophysiology remains to be clarified. We examined 14-3-3 proteins, which are acidic brain proteins, in cerebrospinal fluid by immunoblotting in four patients with influenza-associated encephalopathy, four patients with influenza without encephalopathy, and four patients with another encephalopathy. Interestingly, we detected 14-3-3 proteins in all four patients with influenza-associated encephalopathy (100%) but not in any of the other patients. 14-3-3 isoforms, including beta, gamma, epsilon, xi, and theta, were found in the cerebrospinal fluid of the patients with influenza-associated encephalopathy, suggesting extensive damage to the brain. We conclude that 14-3-3 proteins in cerebrospinal fluid are highly detectable in influenza-associated encephalopathy and thus can be used as a rapid diagnostic marker.