"As of right now I do not have it," Gaga told King in a show that airs Tuesday night. "But I have to take good care of myself.
The 24-year-old pop superstar, who nearly collapsed on stage last month, said lupus runs in her family, and killed her aunt Joanne. But she reassured fans that she has not yet shown any symptoms.
A borderline positive lupus test result antibody tests are at the upper limit of what is considered normal.
Lupus is a chronic autoimmune disease that affects connective tissue. It primarily affects women and kills by attacking the heart, lungs liver, kidneys and nervous system. With treatment, victims can live for decades.