I've read this post several times, but I'm not sure I fully understand the science behind it.
If I try and explain to you what I think it means, I'd be really grateful if you could point out where I've got it wrong:
An antibody normally has one type of protein, (or peptide chain), on its surface, so that it binds to one specific antigen.
If the protein on an antibody's surface matches the body's own tissue, it will be destroyed.
Some B-cells have two types of protein on the surface -- one for self tissue, the other for "foreign" tissue.
Because they are not exclusively aimed at self tissue, they are not destroyed.
They can attach to self tissue and trigger an attack, or even act as the glue between foreign and self tissue.
That's my interpretation of this finding but I'm really not confident about my understanding... any help would be greatly appreciated!