Lack of type C virus antibodies in systemic lupus erythematosus.

Twelve systemic lupus erythematosus (SLE) and 10 normal sera were similarly reactive in an assay for cytotoxic antibody to type C virus-infected and uninfected cells, but both were less cytotoxic for infected cells. Thus antibodies to type C viruses were not detected in SLE or normal sera, but type C infection may interfere with antibody recognition of other cell membrane antigens.