Kelly, 27, who presents Fashion Police on American TV, had accused the singer of being "disrespectful" by refusing to walk on the red carpet at the Grammy Awards last weekend - which prompted an angry response from some of Gaga's "little monsters".
She listed the sick messages she had receievd from Gaga fans, saying it was "no wonder they get called bullies".
And she tweeted: "Being told to kill myself, having ppl hoping i get raped being called fat/ugly, & being sent death threats IS A BIG DEAL!
"@ladygaga really has created monsters. w/ every nasty unjustified tweet u send me u shame your queen. hate it not what @ladygaga is about!"
Her original comment about Gaga had been: "Being part of the music industry is walking the red carpet. You say hello to your fans and you give back to those reporters and those people who supported you. And when you go to an awards show and you don’t walk the red carpet, I find that disrespectful."
But she insisted she was still a Gaga fan, saying: "I love [her] I'm a huge fan she is amazing… i just gave one opinion and people went nuts!
"I don't label [her] entire fan base as bullies because i know they are not but some really are giving you guys a bad rep!"
Kelly also recently crossed swords with Christina Aguilera fans who had taken exception to her calling the singer a "fat bitch" on fashion police last year.
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