Self antigens are particularly important for which cells?

• A. Neurons
• B. Epithelial cells
• C. Platelets
• D. RBCs

Answer: (D)

Self antigens are markers that identify a person’s own cells and prevent immune attack. On red blood cells, these markers are the ABO and Rh antigens that determine an individual’s blood type. They’re especially important because transfusion safety hinges on matching these antigens; if donor red cells carry antigens not present on the recipient’s cells and the recipient has antibodies against them, the transfused cells can be rapidly destroyed. This makes red blood cells the primary focus for understanding how self antigens guide immune recognition in practical terms. Other cells have surface markers too, but mismatches in RBC antigens most clearly drive transfusion reactions and immune responses.