Elevated Serum Levels of Soluble Adhesion Molecules ICAM-1 and ELAM-1 in Patients with Severe Atopic Eczema and Influence of UVA1 Treatment

Abstract

ICAM-1 is known to be strongly expressed on keratinocytes in lesional atopic eczema correlating with the degree of inflammation. ELAM-1 was found to be expressed on dermal vascular endothelium in lesional atopic eczematous skin. The present study was performed to investigate whether elevated serum levels of soluble forms of these molecules are detectable in patients with severe atopic eczema and whether these parameters could be useful markers for disease activity. Serum levels of soluble ICAM-1 (sICAM-1) and ELAM-1 (sELAM-1) were measured by ELISA in 18 patients with severe atopic eczema before and after UVA1 therapy. Before onset of treatment, serum sICAM-1 (565 +/- 99 ng/ml) and sELAM-1 (89.7 +/- 29.9 ng/ml) levels were significantly (p < 0.001) elevated compared to 22 healthy control persons (296 +/- 46 and 48.8 +/- 22.7 ng/ml). After achievement of significant clinical improvement after 3 weeks of UVA1 therapy, there was neither a decrease in serum sICAM-1 nor in sELAM-1 levels. The posttherapeutic serum sICAM-1 and sELAM-1 values remained elevated (p < 0.001) above the normal range. Based on these data we suggest that (1) serum sICAM-1 and sELAM-1 are elevated in patients with severe atopic eczema, (2) sICAM-1 does not decrease together with reduction of ICAM-1-positive keratinocytes in atopic eczema following clinical improvement and might therefore be mainly of a different origin, i.e. leukocytes/endothelial cells, and that (3) sICAM-1 and sELAM-1 seem not to be suitable markers of actual disease activity in severe atopic eczema.