ADHESION MOLECULE EXPRESSION AND ENDOTHELIAL-CELL ACTIVATION IN CUTANEOUS LEUKOCYTOCLASTIC VASCULITIS - AN IMMUNOHISTOLOGIC AND CLINICAL-STUDY IN 42 PATIENTS

Objective: To investigate the sequential expression of adhesion molecu les on endothelium and inflammatory cells in cutaneous leukocytoclasti c vasculitis, and the relation of these adhesive molecules with clinic al and histologic variables. Design: An immunohistochemical analysis ( streptavidin-biotin-peroxidase technique) of 42 vasculitic lesions of up to 96 hours was performed using a panel of monoclonal antibodies sp ecific for different adhesion molecules. Twenty normal skin samples an d 3 perilesional specimens served as control samples. A clinical proto col was also performed, and patients were followed up for 1 to 5 years . Setting: A clinicopathologic research unit of a university hospital. Patients: Forty-two patients, 21 women and 21 men, aged 22 to 79 year s, with cutaneous leukocytoclastic vasculitis. Interventions: Three sk in biopsy specimens of vasculitic lesions from each patient were obtai ned for histopathologic examination on paraffin, direct immunofluoresc ence, and immunohistochemical analysis on cryostatic tissue sections. Main Outcome Measures: The histologic characteristics and the immunohi stochemical-stained specimens were evaluated by 3 independent investig ators, using a semiquantitative method. Results: Increased endothelial expression of very late activation antigen-1, HLA-DR, and intercellul ar adhesion molecule-1 was observed. The induction of E-selectin expre ssion was more marked in recent lesions (P<.001) and correlated with t he proportion of infiltrating neutrophils (P=.03). Endothelial express ion of vascular cell adhesion molecule-1 was restricted to developed l esions. Most infiltrating cells were neutrophils expressing Mac-1. In 1 patient, lymphocyte function associated antigen-1 expression was als o up-regulated. No significant increase in CD3, CD8, or CD71 immunorea ctivity was found. An up-regulation of perivascular cells expressing H LA-DR and vascular cell adhesion molecule-1 was observed in vasculitic lesions. This cellular staining correlated with long-term evolution o f the disease (P=.04). Conclusions: Adhesion molecules are sequentiall y upregulated in cutaneous leukocytoclastic vasculitis. The results of this study support the possible involvement of E-selectin inmediating recruitment of neutrophils expressing Mac-1.