Effects of etanercept on C-reactive protein levels in psoriasis and psoriatic arthritis

Background C-reactive protein (CRP), an inflammation biomarker, indicates cardiovascular risk and is elevated in psoriasis. The effect of etanercept on CRP in psoriasis has not been previously examined. Objectives The primary objective was to examine the effect of etanercept on CRP levels from baseline to week 12 compared with placebo. Secondary objectives included assessment of baseline CRP and relationships between CRP and body mass index (BMI), statin drug use, and Psoriasis Area and Severity Index (PASI) scores. Methods A retrospective analysis was conducted of CRP levels from patients with psoriasis who participated in a randomized, double-blind, placebo-controlled, U.S. registrational study. Data were analysed separately if patients self-reported psoriatic arthritis. Results Baseline CRP levels were elevated in patients with psoriasis with and without psoriatic arthritis. CRP was significantly reduced in both groups after 12 weeks of etanercept treatment. Patients with psoriasis with psoriatic arthritis and patients with higher BMIs had higher median baseline CRP values and greater reduction of CRP values compared with those without psoriatic arthritis and those with lower BMIs. Etanercept lowered CRP levels in statin users and nonusers. Regression analyses revealed an association between baseline PASI score and baseline CRP independent of BMI in patients with psoriasis. Conclusions Patients with moderate to severe plaque psoriasis, with or without psoriatic arthritis, have increased systemic inflammation demonstrated by elevated CRP levels. In psoriasis without psoriatic arthritis, skin disease activity is associated significantly with CRP elevation, independent of BMI, age and sex. Etanercept reduced CRP levels in all but the normal weight psoriasis group without psoriatic arthritis.