Kelly Osbourne ''couldn't be more proud'' of Jack Osbourne for the way he deals with his multiple sclerosis.

The 'Fashion Police' co-host admits her brother's MS diagnosis left the entire Osbourne family in shock and worried for him because of the debilitating effects the degenerative nerve condition can have on sufferers.

Kelly - whose parents are stars Sharon and Ozzy - said: ''If it's not my mom with cancer or dad in a coma or me in rehab - there's always something going on in my family. But we didn't know what to do or where to turn when Jack was diagnosed with multiple sclerosis ... He's my baby brother. I sit there and my lips quiver if I'm looking at Jack and he's having a flare-up. But he looks at me and says, 'Stop it!' I would do anything to take it away from him, but I can't.

''People have no idea how brave Jack is and what he has to go through every day while still having a smile on his face. I couldn't be more proud of him.''

Kelly started working with the charity Race to Erase MS shortly after Jack - who has a two-year-old daughter Pearl with his wife Lisa - was diagnosed with the disease two years ago.

The outspoken star was inspired to do so by her brother's commitment to the charity.

She said: ''I see first-hand what that charity does for people. And having the constant remind of my brother saying, 'It's not just me who has MS, Kelly,' I'll do anything for the cause.''