Figure 2 | Scientific Reports

Figure 2

From: Assessment and Clinical Relevance of Serum IL-19 Levels in Psoriasis and Atopic Dermatitis Using a Sensitive and Specific Novel Immunoassay

Figure 2The alternative text for this image may have been generated using AI.

Circulating IL-19 levels serve as a leading indicator of PASI improvement in psoriasis patients treated with ixekizumab. (a) We obtained samples from 112 psoriasis patients enrolled in a phase 2 study (NCT01107457) for ixekizumab15. Patients were assigned to five treatment groups and were administered placebo or 10, 25, 75, or 150 mg ixekizumab at 0, 2, 4, 8, 12, and 16 weeks. Circulating IL-19 concentrations were measured at baseline and after ≥16 weeks of treatment. All data from baseline and after 16 weeks of treatment are shown. Collectively, serum IL-19 levels were highly correlated with PASI (Spearman’s r = 0.74, p < 0.0001). (b) IL-19 was measured in psoriasis patients from Fig. 2a at baseline and over 16 weeks of treatment. Data are least square means ± standard error of the mean estimated from a mixed effects model using an unstructured covariance matrix. Model fitting was performed using log10 transformed IL-19 concentrations. The dashed horizontal line indicates the upper limit of normal (21 pg/mL). Week 2 comparisons of ixekizumab (IXE) to placebo (PBO): 10 mg (p = 0.28), 25 mg (p = 0.0015), 75 mg (p < 0.0001), 150 mg (p < 0.0001); Week 16 comparisons: 10 mg (p = 0.71), 25 mg (p < 0.0001), 75 mg (p < 0.0001), 150 mg (p < 0.0001). (c) Representative patient profiles from Fig. 2b for IL-19 (solid) and PASI percent change from baseline (dashed). A patient treated with 75 mg of ixekizumab (IXE) is shown on top and a patient treated with 150 mg of ixekizumab is shown on bottom. The dashed vertical line indicates the baseline time point. In each case, IL-19 decreases prior to PASI improvement. (d) Serum IL-19 levels in psoriasis patients from Fig. 2b after 2 weeks (top) and 16 weeks (bottom) of placebo or doses of ixekizumab are plotted versus PASI at 16 weeks. The dashed horizontal line indicates the upper limit of normal. PASI 100 improvements at 16 weeks were preceded by IL-19 reductions to near normal levels after 2 weeks of treatment. Top panel one-way ANOVA (p < 0.0001). Bottom panel one-way ANOVA (p < 0.0001).

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