Type C oncornavirus isolation studies in systemic lupus erythematosus. II. Attempted detection by viral RNA-dependent DNA polymerase assay.

Isolation of type C oncornavirus was attempted from 20 tissues and cell cultures of patients with systemic lupus erythematosus. Chemical inducers, cocultivation and fusion with cells from multiple other species, prolonged subculturing, and the RNA-dependent DNA polymerase assay for virus detection were used. A type C virus was isolated, but was shown to be the endogenous rat virus. Thus the methods, although generally appropriate, were not specifically permissive for replication of a human type C virus. This agrees with the failure of other investigators to isolate a virus of undisputed human origin. Combining available evidence, a fundamental role for type C viruses in lupus erythematosus remains an attractive hypothesis.