Mixed value of TNF-alpha response predictors in AS

Higher CRP values, back pain scores and lower Bath Ankylosing Spondylitis Functional Index scores are predictors of a favourable response to etanercept in patients with ankylosing spondylitis, according to recent findings. However, the researchers note that the predictive value of these factors is insufficient to guide the treatment of individual patients.To identify patient and disease characteristics that influence response to etanercept Dr John Davis and colleagues randomly allocated 277 patients to etanercept (25mg twice-weekly subcutaneous injections; n=138) or placebo (n=139) for 24 weeks.Using logistic regression analysis the investigators found that CRP, back pain score, and BASFI score were associated with a treatment response to etanercept [as measured by the Assessment in Ankylosing Spondylitis Response Criteria (ASAS 20)]. However, lower CRP levels and less pain were associated with a response to placebo.Reflecting on their findings the investigators highlight that the predictive value of these factors was so low that they should not be used to determine treatment in individual patients, "clinicians should not withhold treatment based on these variables alone," the authors comment.Davis's group conclude that higher CRP values and back pain scores and lower BASFI scores are significant predictors of a higher ASAS 20 response in patients with AS receiving etanercept but the predictive value of these factors is insufficient to guide the treatment of individual patients.Reference...