Patients with paroxysmal nocturnal hemoglobinuria lack which complement regulatory components on the host cell surfaces?
A) Factor H and Factor I
B) Decay accelerating factor (DAF) and CD59
C) Membrane cofactor protein (MCP) and C1INH
D) Homologous restriction factor (HRF) and properdin

Question

Quizplus · Accepted Answer

Patients with paroxysmal nocturnal hemoglobinuria have a mutation in the PIG-A gene of hematopoietic cells. This defect leads to a mutant version of the glycosylphosphatidylinositol protein (GPI), which serves as a membrane anchor for surface proteins. As a result, blood cells lack the surface proteins DAF and CD59 that inhibit complement activation on host cells, and cells are lysed inappropriately, leading to red cell hemolysis and anemia.

Patients with Paroxysmal Nocturnal Hemoglobinuria Lack Which Complement Regulatory Components