SPARTAN is a research and treatment network organization that includes expert clinicians and researchers who care for patients with spondyloarthritis. At this 15th Annual meeting research was presented that increases our understanding of these disorders that affect the spine.
Ankylosing spondylitis (AS) is an inflammatory disease of the spine that has been associated with a genetic predisposition, HLA-B27. HLA-B27 accounts for 80% of the genetic predisposition to developing AS. HLA-B27 proteins attach to degraded proteins and present them on the surface of cells to other immune cells, lymphocytes. Different types of lymphocytes are able to initiate and perpetuate an immune response that may result in the manifestations of AS.
Of interest, is the fact that about 7.5% pf Caucasians in the United States are B27positive but do not develop AS. This fact suggests that other genetic factors need to be present for the disease to appear.
Robert Colbert, MD of the National Institutes of Health presented his data regarding the importance of ERAP-1 in the development of spondyloarthritis. ERAP stands for endoplasmic reticulum aminopeptidases. These proteins work in a specific portion of the cell (endoplasmic reticulum) to cut proteins to a correct size to fit into other proteins like the HLA-B27 molecule. In animal models of a form of spondyloarthritis, the deletion of ERAP 1 from the genetic makeup of the animal prevents the development of components of the illness. However, the removal of ERAP 1 does not decrease the gut inflammation these animals experience.
The therapeutic implications of this model are important. Controlling ERAP effects may control some components of the illness associated with a variety of autoimmune disorders. TH17 pathway produces cell messengers like tumor necrosis factor (TNF), interleukin 17, and interleukin 23. Therapies are available against these factors that have beneficial effects on many of the disorders associated with spondyloarthritis. The hope remains that therapies directed against ERAP will add to the control of this group of spinal disorders.
Colbert R. Session on HLA-B27/ERAP-1 antigen presentation and autophagy in the pathogenesis of SpA. Proceedings from the 2017 Annual Spartan meeting
Navid F, Colbert RA: Causes and consequences of endoplasmic reticulum stress in rheumatic disease. Nature Rev Rheumatol 2017;13:25-40
DAVID BORENSTEIN, MD EXECUTIVE EDITOR THESPINECOMMUNITY.COM