Elevated levels of anti-CD9 antibodies in the cerebrospinal fluid of patients with subacute sclerosing panencephalitis.

Subacute sclerosing panencephalitis (SSPE) is a slowly progressive and highly lethal disease of the central nervous system. Although the primary cause of SSPE is believed to be persistent infection of neuron and glial cells by a measles virus, the precise mechanism of the progression of this disease has not yet been elucidated. CD9, a member of the tetraspanin family, is expressed in myelin and other nervous tissues.