Derek has been in a coma since entering ICU in March with COVID-19.
Speaking on Good Morning Britain, Piers says Kate is "living in hope".
While interviewing a nurse who battled the virus for 93 days in ICU, Piers mentioned his colleague's ordeal.
He said: "We have one of our own, Kate Garraway, whose husband is in this terrible position.
"We wish them, as always, all the very best, but they’re living in hope."
The dad-of-two has beaten coronavirus, but remains in a coma with many additional health symptoms.
He now has a hole in his heart, requires kidney dialysis and is diabetic.
Kate has spoken of her husband's health on several occasions.
Earlier this month she gave a tear-jerking interview from her North London garden to GMB.
She said that she was holding on to hope, but that coronavirus had ravaged her husband's body.
She explained: "He’s very, very sick. And as time goes on… It’s a virus, it’s like a computer virus I think.
"The doctors manage one bit extraordinarily well and there seems to be a flicker of hope, and then other things emerge and they’re fighting that.
"It’s affected him from the top of his head to the tip of his toes."
She added that she still saw a positive light at the end of the tunnel - as he was now COVID-19 free.
Kate continued: "Let's look at some of the positives.
"He’s now COVID-free so he’s testing negative for the COVID virus.
"The fight with the virus has been won and he’s still here.
"But it’s wreaked extraordinary damage on his body and we don’t know if he can recover from that."
She heartbreakingly revealed that Derek had begged both her and doctors to put him in a coma:
"He couldn't really speak to me because of the mask, but he was begging me, 'I feel like I'm suffocating, please let them put me in a coma.
"But I said 'no we've got to wait' because if his lungs can handle it that's better.
"Then on the Sunday morning they rang me up and said we're going to be him in a coma, and he just said to me 'I love you, I have to leave you', and I said 'it's only for three or four days and you're going to fine this is good and good.'"
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