Soluble intercellular adhesion molecule-1 and procollagen III peptide are reliable markers of disease severity in psoriasis.

Levels of soluble intercellular adhesion molecule-1 (sICAM-1) and procollagen III peptide (PIIIP) were measured respectively by enzyme immunoassay (EIA) and radioimmunoassay (RIA) methods in sera from 14 patients affected with psoriasis. The same determinations were also performed on suction blister fluids (BFs) obtained from lesional and non-lesional skin. Fourteen normal subjects were used as controls. Significant correlations were found between the serum levels and psoriasis area and severity index (PASI), (R = 0.62 for sICAM-1 and R = 0.73 for PIIIp, respectively). Of the PASI components, infiltration and erythema represented the variables most closely related to PIIIP (R = 0.85; R = 0.72 respectively). Differently from PIIIP, whose levels were significantly lower in the sera than in skin BFs (serum: median value 1.05, range 0.7-2.3 vs. lesional skin fluid: 11.8, 4.8-30 U/ml), sICAM-1 molecules were found predominantly in the sera (serum: median 316, range 117-579 vs lesional skin fluid: median 70, range 31-252 ng/ml). These data cannot exclude that sICAM-1 molecules detected in suction BFs may derive from serum contamination.