C reactive protein (CRP) levels may be an effective predictive measure to assess treatment response to anti-tumor necrosis factor (TNF) therapy in patients with ankylosing spondylitis (AS), according to study findings published in Seminars in Arthritis and Rheumatism.
Researchers analyzed post hoc results from 4 randomized controlled trials, which involved determining whether or not baseline and post-baseline CRP levels have predictive value in relation to treatment response of anti-TNF therapies. Investigators analyzed patient data with the anti-TNF biologic etanercept, which has shown efficacy in the treatment of AS. Various responses after 12 weeks of therapy were evaluated with respect to CRP levels.
After statistical analysis, researchers found that baseline CRP levels were considered either very high, high, or normal in 23%, 34%, or 43% of treated patients, respectively. Furthermore, they reported that having a very high baseline CRP strongly predicted treatment outcomes after 12 weeks of anti-TNF therapy.
Primary study limitations included the post hoc design and lack of long-term clinical outcome measures.
“Our results suggest that baseline CRP can be predictive of a patient’s response to treatment, which is consistent with previous reports,” the researchers wrote.
Further studies are needed to fully understand the predicative value of CRP levels in the treatment of patients with ankylosing spondylitis.
Baraliakos X, Szumski A, Koenig AS, Jones H. The role of C-reactive protein as a predictor of treatment response in patients with ankylosing spondylitis [published online November 2, 2018]. Semin Arthritis Rheum. doi: 10.1016/j.semarthrit.2018.10.019