RESUMO
To further investigate the immunological mechanisms involved, we analyzed the expression of costimulatory molecules in aortic tissue and their counterpart molecules on infiltrating cells of patients with Takayasu's arteritis. We also examined the expression of major histocompatibility complex (MHC) class I chain-related (MIC) A in aortic tissue, which is known to be induced by external stress, and its counterpart NKG2D receptors on infiltrating cells. Among these costimulatory molecules, strong expression of 4-1BBL and Fas was induced in the aortic tissue, and most of the infiltrating cells expressed 4-1BB and FasL, suggesting these pathways play critical roles in T-cell-mediated vascular injury. We also found that MICA was strongly induced in the aortic tissue and that at least part of the infiltrating cells expressed NKG2D receptors. Some infiltrating cells - but not vascular smooth muscle cells - seemed to have undergone apoptosis. Our findings strongly suggest that 4-1BB/4-1BBL and Fas/FasL pathways play important roles in vascular injury in Takayasu's arteritis. We assume that gammadelta T cells infiltrated aortic tissue recognizing MICA, resulting in the induction of MHC antigens and costimulatory molecules, and then alphabeta T-cells infiltrated recognizing some auto-antigens presented by MHC antigens, leading to chronic inflammation.
Assuntos
Antígenos de Histocompatibilidade Classe I/metabolismo , Arterite de Takayasu/imunologia , Arterite de Takayasu/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Receptor fas/metabolismo , Ligante 4-1BB , Idoso , Antígenos CD/metabolismo , Aorta/imunologia , Aorta/metabolismo , Aorta/patologia , Apoptose/imunologia , Antígeno B7-1/metabolismo , Antígeno B7-2 , Ligante CD27 , Ligante CD30 , Antígenos CD40/metabolismo , Feminino , Humanos , Marcação In Situ das Extremidades Cortadas , Linfócitos/metabolismo , Linfócitos/patologia , Masculino , Glicoproteínas de Membrana/metabolismo , Proteínas de Membrana/metabolismo , Pessoa de Meia-Idade , Subfamília K de Receptores Semelhantes a Lectina de Células NK , Ligante OX40 , Receptores Imunológicos/metabolismo , Receptores de Células Matadoras Naturais , Arterite de Takayasu/patologiaRESUMO
A 17-year-old man noted a painful mass on his wrist while fencing (Kendo). An aneurysm of a dorsal superficial antebrachial artery, which is an anomalous branch of the radial artery in the distal forearm, was diagnosed. He was successfully treated by excision with primary anastomosis; pathologic examination revealed a pseudoaneurysm. The anomalous location of this artery placed it at risk for civilian injury as it ran in the subcutaneous tissue of the dorsal forearm.
