I'm not suggesting anything, just trying to explain the little bit about Prof Ebringers theory that I have read. If an hla-b27 negative with AS has one of the similar genes (B39/40, B7, or H8) then the gene could have a less similar surface protein to klebeislla than B27. it could even work the other way and be more similar than B27. I'm not sure how this affects the severity as there are numerous other factors but I can see how the more similar the gene and germ are then the more likely chance of an auto-immune response. Just guessing though.
