Virological studies in amyotrophic lateral sclerosis.

Complement-fixing antibody response to eleven different viruses were measured in amyotrophic lateral sclerosis (ALS) patients, contacts of ALS patients, neurological controls, and normal controls. The normal controls showed a decreased response to adeno-associated virus and an increased response to adenovirus when compared to the other groups. Levels of interferon-like substances also were investigated in sera and cerebrospinal fluids of ALS patients and neurological controls. Responses were of a low titer and were not increased in the ALS group. Explant cultures were established from tissues of 24 ALS autopsy cases. Cultures were investigated directly or following fusion to various indicator cell lines for viral-like agents. Techniques such as interference assays, 5-bromodeoxyuridine (BudR) induction, hemadsorption, and fluorescent antibody staining failed to detect virus. By addition of helper adenovirus to primary explant cultures, adeno-associated virus was isolated from 2 of 11 ALS cases.