A question about the word 'blood' meaning 'a close relative'?

In an article about a family in Queens, New York, a young man, seventeen years old, who had lost both his father and mother to Coronavirus, and, together with his sister, had contracted the disease yet recovered, stated :

“Because it’s just me and my sister [left], we sort of have to rely on each other," he said. “We were the only blood left.”

MSN News – 22nd September 2020

I had not come across the word ‘blood’ used in this way, but then I am a Brit.

Does it mean, simply, a close relative ?

Is this an American English expression ?

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EDIT : I have a vague recollection of hearing someone address someone else as ‘blood’ but that may be a false memory triggered by association.

P.S. I know my header title is a little ungrammatical but the system did not allow me to put a full stop. I had to add a question mark, for reasons that I fully understand.