Innate immunity of spondyloarthritis: the role of toll-like receptors.

Amongst the spondyloarthropathies (SpA), the relationship of host susceptibility and environmental triggers is best seen in reactive arthritis (ReA). There are several points from the clinical studies of ReA which highlight important unresolved issues in the pathogenesis. Innate and adaptive immune responses are distinct, but complementary aspects of host defense (Pacheco-Tena et al, 2002, Beutler et al, 2006).Innate immunity is critically dependent upon non-variant, genetically encoded receptors for highly conserved structures known as pathogen-associated molecular patterns (PAMP). The receptors themselves are termed pattern-recognition receptors (PRR). Among the PRR, toll-like receptors (TLR) play a central role.