Plasma concentration of selected neuropeptides in patients suffering from psoriasis

The aim of this study was to evaluate plasma levels of substance P (SP), calcitonin gene-related peptide (CGRP), vasoactive intestinal peptide (VIP) and neuropeptide Y (NPY) during psoriasis course.

Seventy-three patients with psoriasis and 32 healthy volunteers were included. Detailed demographic and disease anamnesis was obtained from every patient. The disease severity was assessed using the Psoriasis Area and Severity Index score. Plasma levels of SP, CGRP, VIP and NPY were measured radioimmunologically.

Plasma levels of SP and NPY did not significantly differ between patients with psoriasis and controls (median SP: 52.8 and 57.9 pg/ml, respectively; P = 0.32; median NPY: 8.5 and 8.2 pg/ml, respectively; P = 0.67). CGRP plasma concentration was significantly elevated in psoriatic individuals both before (median 43.1 pg/ml) and after treatment (median 45.4 pg/ml), in comparison with healthy donors (median 13.5 pg/ml; P < 0.01 and P = 0.03, respectively). Treatment did not significantly influence plasma CGRP levels (P = 0.3). Median VIP plasma concentration in psoriatics before treatment was significantly higher compared with healthy controls (medians 66.9 and 60.1 pg/ml, respectively; P = 0.04), but the therapy resulted in significant decrease in VIP plasma level (median 19.0 pg/ml; P < 0.001). In psoriatic patients significant correlations were noted between NPY and VIP (R = 0.34; P < 0.01), and VIP and CGRP plasma levels, both before (R = 0.28; P = 0.03) and after the treatment (R = 0.44; P < 0.01).

Based on our results and previous literature data it could be suggested that neuropeptides may be involved in the development of psoriatic lesions.