ICAM-1 expression on endothelium and systemic cytokine production in cutaneous neutrophilic leukocytoclastic vasculitis in NZBxNZWF₁ mice

T. Hayashi, K. Hasegawa and N. Ichinohe

Laboratory of Veterinary Pathology, Faculty of Agriculture, Yamaguchi University, Yoshida, Yamaguchi, Japan

Offprint requests to: Dr. T. Hayashi, Laboratory of Veterinary Pathology, Faculty of Agriculture, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8515, Japan. Fax: +81 83 933 5890. e-mail: hayasi@yamaguchi-u.ac.jp


Summary. The present study has examined relationship between cutaneous microvessel injury and adhesion molecule expression on the endothelium by cytokines in NZBxNZWF₁ (B/WF₁) mice, a model for human systemic lupus erythematosus. In advanced ages associated with overt clinical manifestation, but not in early ages, neutrophils with a minor proportion of monocytes and lymphocytes mainly adhered to the endothelium of capillary and the venule with fragmentation (leukocytoclasis), leading to the vascular injury (leukocytoclastic vasculitis). This was confirmed by the leak of monstral blue from the blood vessel. At this stage LFA-1⁺ leukocytes adhered to intensely expressed ICAM-1 on the endothelium, and this was paralleled with a significant rise in IL-1alpha and TNF-a in the circulation. The present study suggests that IL-1alpha and TNF-alpha may, at least in part, be responsible for the increased ICAM-1 expression on endothelium in cutaneous microvessels, resulting in the vascular injury characterized by neutrophilic leukocytoclasis in B/WF₁ mice. Histol Histopathol 20, 45-52 (2005)

Key words: B/WF₁ mouse, Microvessel, Adhesion molecule, Neutrophil, Cytokines, Vasculitis, Endothelium, Leukocytoclasis