We didn't lose friends because we didn't have any as adults. My wife is from another country and I moved around a lot and only contact friends via email. My 7 year old ASD daughter never a had friend as far as I can tell. Her classes are usually with all ASD boys. She doesn't act like she wants friends but other kids steer clear of her because of the autism I guess.

I've lost friends, but I wouldn't say it's due to my brother's Autism. In fact, many of my friends are supportive and love his drawings. Often enjoying hearing about him. If they are treating you and you son this way, they probably aren't your real friends.