Lady Gaga has "tested borderline positive" for lupus, she revealed this week. The singer, who recently complained of heart palpitations, said that she is genetically predisposed to the connective tissue disease but otherwise "shows [no] symptoms".

"[I] have to take good care of myself," Gaga told CNN's Larry King. "Lupus is in my family and it's genetic." She has been examined by doctors and "as of right now, I don't have it", she said. "I don't show any signs, any symptoms of lupus, but I have tested borderline positive."

Lupus, an autoimmune disorder, is treatable but still dangerous. Author Flannery O'Connor died of the disease in 1964, and decades later it continues to claim victims. Gaga's aunt Joanne is thought to have died of the disease when she was just 19.

"I'm connected to my aunt, Joanne, who died of lupus," Lady Gaga told the Times last week. "It's a personal thing." The singer explained that she had recently suffered from "heart palpitations and ... fatigue and other things". At an April concert in Tokyo, the pop star said she had trouble breathing. "I had a little oxygen, then I went on stage," she recalled. "I was OK. I don't want my fans to be worried about me."

Gaga dropped another bombshell in the Larry King interview: she was scheduled to open for Michael Jackson at his O2 Arena residency. "You know, it's always difficult because I don't necessarily like to talk about those personal things," she said. "I guess I can speak about it now. I was asked to open for Michael on his tour."

"We were working on making it happen. And there was talk about the openers doing duets with Michael. But his death was devastating for me regardless of whether I was supposed to go on tour with him ... Some of my fascination with death and the demise of celebrity [comes from] watching people I have admired become destroyed, whether by themselves or by the media."