Tina Turner is gearing up to release her autobiography, Tina Turner: My Love Story, in which she reveals that husband, German music executive Erwin Bach, donated one of his kidneys to her when she desperately needed a transplant to save her life.

Excerpts obtained by The Jasmine Brand indicate Turner’s kidneys were functioning at “20 percent and plunging rapidly.” When Bach offered to give up a kidney to save Turner, she was “shocked” by the lifesaving gesture.

“[He] shocked me by saying that he wanted to give me one of his kidneys…[I was] overwhelmed by the enormity of his offer.”

Once all was said and done, Turner shared her excitement about the successful procedure.

“[I felt] happy, overwhelmed and relieved that we’d come through this alive.”

Turner, 78, married Bach, 72, in a private ceremony in 2013, and she is now a Swiss citizen.