Immunobiologic analysis of arterial tissue in Buerger's disease

Abstract

Introduction: The cause of thromboangiitis obliterans (TAO) still remains unknown. We have reported that immunologic injury associated with T lymphocytes infiltration might be the initial etiologic mechanism in TAO. The present study was undertaken to examine further the mechanism of immune injury. Methods: Arterial walls affected by TAO were obtained from eight patients with eight non-pulsatile arteries and one patent artery. Immunohistochemical and TUNEL studies were performed for phenotyping of the infiltrating cells with CD4 (helper T cell), CD8 (cytotoxic T cell), CD56 (natural killer cell), and CD68 (macrophage), for identification of cell activation with VCAM-1 and i-NOS, for the presence of cell death with TUNEL analysis, and for inflammatory cytokine detection with RT-PCR. Results: The characteristic features were luminal obliteration, together with a varying degree of recanalization. T cells infiltrated mainly in thrombus, intima, and adventita. Among infiltrating cells, CD4 T cells greatly outnumbered CD8 cells. VCAM-1 and i-NOS were expressed in endothelial cells around the intima (patent segment) or vaso vasorum (occluded segment). Endothelial cells in vaso vasorum stained positive with TUNEL. Interferon-γ mRNA was detected in two specimens. Conclusions: Our results suggest that T cell mediated immune inflammation is a significant event in the development of TAO.