Rheumatoid arthritis
|
Spondyloarthropathy
|
MHC association—HLA-DR4 | MHC association—HLA-B27 |
CD4 T cells which contribute to inflammation are depleted in advanced HIV | CD8 T cells also diminish but are spared compared with CD4 cells |
|
Primary target tissue | Primary target tissue |
The synovial membrane | Sites of increased biomechanical stress in the joints, especially the enthesis, adjacent marrow, capsules |
|
Triggers—unknown | Triggers—bacteria/virus (including HIV) |
Rheumatoid factors? | Genitourinary and bowel inflammation may be commoner in homosexuals, thus allowing greater access of bacteria to the circulation |
Infection? |