Cd 59 Immunohistochemistry Bone Marrow

CD59 is expressed in all organs and in almost all cell types. It is essential to protect cells from self-destruction by complement-mediated lysis. The highest expression in humans has been detected in cardiomyocytes and smooth muscles (Su et al., 2004). Some nucleated blood cells (CD14 monocytes, T cells) either lack CD59 expression or express it very low which makes them highly susceptible to complement lysis. This condition is called paroxysmal nocturnal haemoglobinuria (PNH) and is a clonal disorder of RBCs. As a result of defective PIGA function, affected RBCs lack all GPI-linked membrane proteins, including CD59. The lack of CD59 renders PNH-RBCs susceptible to autologous complement lysis. The major and well-studied role of CD59 protein is to protect cells from self-destruction by our complement system. CD59 is the only membrane-bound inhibitor of the terminal pathway of complement cascade. However, in more recent years, some other functions of CD59 were described. CD59 was found to attenuate angiogenesis by preventing the complement-mediated lysis of newly grown blood vessels.