Select the best statement from the following choices to describe the pathogenesis of PNH.
A) Increased hemolytic episodes are produced as a result of complement binding to erythrocytes via IgG antibodies in cold temperatures.
B) Increased hemolytic episodes are produced as a result of missing cell membrane proteins that regulate complement activation.
C) Increased hemolytic episodes are produced as a result of missing enzymes necessary for ATP production in erythrocytes.
D) Increased hemolytic episodes are produced as a result of initiation of an immune response against erythrocytes.

Question

Quizplus · Accepted Answer

PNH is caused by a deficiency or absence of cell membrane proteins, specifically CD55 and CD59, which regulate complement activation by preventing the formation of the membrane attack complex (MAC). Without these proteins, the MAC can form on erythrocytes, leading to increased hemolysis. This is not due to IgG antibodies in cold temperatures or missing enzymes for ATP production. Though there may be some immune response involved, the primary cause is the missing cell membrane proteins.

Select the Best Statement from the Following Choices to Describe