Serological level of ICAM and ELAM adhesion molecules in allergic vascularitis

A 24-patient lot with hypersensitivity vasculitis was investigated for serological determinations of ICAM and ELAM adhesion molecules. Determinations were made in attack and in remission. Over two thirds of the cases presented elevated serological levels of ICAM and ELAM in attack, with twofold higher values than normal. In remission, in the absence of clinical signs, ICAM and ELAM values were normal in 19 cases (ICAM) and 22 cases (ELAM). Serological level of ICAM and ELAM was concordant with serological level of IL-2, IL-6, circulating immune complexes and clinical status. The increased values of ICAM and ELAM are due to the expression of these molecules both on the surface of endothelial cells and on immune cells. The adherence of leukocytes on the endothelial cells, by adhesion molecules involvement, followed by their extravasation represents an important event in the vascular lesion pathogeny of the hypersensitivity vasculitis.