Quantifying the genetic risk for the development of axial spondyloarthropathy: could this become a diagnostic tool?

To assess the utility of recent genetic findings in ankylosing spondylitis (AS) and axial spondyloarthropathy (SpA) in relation to diagnostic testing, prognosis and responses to biologic treatment and the development of new therapies.

AS and other forms of SpA are polygenic with more than 100 genes contributing to disease susceptibility. The role of genes in determining the outcome of the disease and response to treatment is less clear. Here, we review some of the progress that has been made over the past decade in understanding the genetic contribution to these diseases and how this may be used to inform the development of new treatments. In those with a high pretest probability of SpA human leukocyte antigen (HLA)-B27 testing can increase the posttest predictive value to almost 100% in some cases. There are currently no reliable genetic predictors of disease severity or response to treatment.

The utility of HLA-B27 as a diagnostic tool when coupled with careful clinical assessment is well established but other genetic markers probably have relatively little to add. In contrast, novel drug targets are likely to be identified from genetic association studies.