Gene Expression Profiling of Toll-Like Receptor 4 and 5 in Peripheral Blood Mononuclear Cells in Rheumatic Disorders: Ankylosing Spondylitis and Rheumatoid Arthritis

Abstract: Spondyloarthropathies (SpA), defined by inflammatory situations, are a category of rheumatic diseases with mainly involvement of the spine, enthuses, and peripheral joints.1 Ankylosing spondylitis (AS), as the prototype of this category, is an autoimmune disease with a chronic inflammatory arthritis which is characterized by axial skeletal ankylosis, inflammation at the entheses, and arthritis of the peripheral limbs.2 AS shows a strong association with Human Leucocyte Antigen (HLA)-B27 hereditary, and the misfolded HLA-B27 heavy chain homodimer in an animal model has supported the important role of this molecule in the pathogenesis of AS.3 Toll-like receptors (TLRs) are categorized as type I integral membrane glycoproteins which play important roles in the innate immune system. In human, 11 members of TLR family have been identified.4 There is an evidence demonstrating the role of TLR4 in the perforin production by helper T cells in ankylosing spondylitis.5 Nevertheless, it has been demonstrated that the level of TLR4 protein on peripheral-blood leucocytes of AS patients and healthy individuals is Keywords: Ankylosing spondylitis; Gene expression; HLA-B27 antigen; Rheumatoid arthritis; Toll-Like Receptor 4; Toll-Like Receptor 5