Ankylosing Spondylitis                                  Ankylosing => stiffening Spondylitis => inflammed vertebrae  Note: Hovering mouse over images will give addtional information.                     Ankylosing Spondylitis (A.S.) is chronic arthritis of the spine, and over time, fusion of vertebrae occur. Considered autoimmune due to a strong link of the HLA-B27 gene (an MHC-1 molecule) in > 90% cases. [Remember MHC-1 is a Intracellular antigen presenting molecule on surface of all Cells.] The scientific cause of the disease is Unknown, however A.S. is thought to be T cytotoxic mediated due to MHC-1. Another theory is Cross-reactivity of Klebsiella antigens with HLA-B27 molecule.  Young males are mostly likely to have A.S. Symptoms include: Lower back Pain, limited motion of spine A clinical Sign: Sarcoiliac joint inflammation and pain. Diagnosis: X-ray, Medical History, HLA-27 test Treatment is supportive Improve quality of life, control pain Surgery to correct spine   Credit: Brian Lee