An Open Label Study of the Effects of Eculizumab in CD59 Deficiency

The investigators have identified patients with CD59 deficiency that suffers from chronic hemolysis and peripheral demyelinating disease. It was shown that complement terminal pathway can cause inflammation in the peripheral nervous system. Complement can greatly increase the immune attack in the nerves. Eculizumab has already been shown to be effective in a rare blood disorder known as paroxysmal nocturnal hemoglobinuria (PNH). Attacks of PNH are also mediated through complement. Therefore, the investigators of this study are investigating whether by 'turning off' complement in CD59 deficiency, further attacks of hemolysis and nerve injury can be avoided and whether the neurological status will ameliorate.