Khloé Kardashian ''fears'' for Rob Kardashian's health after the Kardashian sisters block Blac Chyna's trademark request.

The 'Keeping Up with the Kardashians' stars - Kim, Kourtney, and Khloé Kardashian - recently submitted documents preventing the 28-year-old model from placing a trademark on her full name Angela Renée Kardashian, but now Khloé is reportedly concerned over the affect the feud may have on her brother Rob, who is engaged to Chyna.

An insider reportedly told HollywoodLife.com: ''Khloé loves Rob and fears what a family feud like this could do to his health and so she tried and failed to prevent her sisters from filing legal papers against Blac.

''Khloé is not happy about the situation and wants her family to just get along.''

And the source also claimed that it was older sisters Kim, 36, and Kourtney, 37, who reportedly ''convinced'' their younger sister Khloé, 32, into filing the documents.

They added to the publication: ''Khloe was the lone dissenter in the filing of legal documents to prevent Blac from using the Kardashian name.

''Kim and Kourtney ultimately convinced Khloe to stand by their side in keeping Blac from marketing their name but Khloe was the one sister who was resistant.''

The news comes after it was previously reported that Chyna - who shares newly born daughter Dream with her fiancée Rob, 29, as well as four-year-old King Cairo from a previous relationship with Tyga - had been left ''heartbroken'' by the ordeal.

A source said: ''Blac [Chyna] is really heartbroken over this whole name feud.

''She thinks it's just sad that the Kardashian family can't stop thinking for themselves and just accept her as one of them. Her and Rob [Kardashian] are practically married and she's the mother of his child - why can't they accept that?

''She thinks they are total fakes, pretending to welcome her into the family. It was all bulls**t.''