Targeted Therapy with Eculizumab for Inherited CD59 Deficiency

Abstract

Patients with CD59 deficiency have progressive neurologic dysfunction and episodes of hemolytic anemia. Eculizumab, a complement inhibitor, was administered to reverse hemolytic anemia in a patient. After the anemia improved, neurologic improvement was also noted.To the Editor: Inherited CD59 deficiency is a rare disorder that manifests in childhood with recurrent hemolytic episodes and severe neurologic symptoms.(1) No specific treatment exists. We report on a child with inherited CD59 deficiency who had a response to the anti-C5 monoclonal antibody eculizumab. The patient presented at 7 months of age with bulbar symptoms: an inability to swallow and generalized severe muscular hypotonia with absent muscle reflexes. During febrile episodes at 18 and 20 months of age, direct antiglobulin test-negative hemolysis, acute kidney failure, and progressive neurologic impairment occurred (Table 1; further details are provided in the Supplementary Appendix, ...