Which statement correctly describes immune antibodies?

Which statement correctly describes immune antibodies?

• A. Mainly IgG
• B. Cross the placenta
• C. React best with antiglobulin
• D. All of the above

Answer: (A)

Immune antibodies are formed after exposure to an antigen, and the class most commonly involved is IgG. This is the hallmark that underpins their behavior in transfusion medicine: IgG antibodies are detected with antiglobulin (AHG) testing rather than by immediate spin, and their IgG nature allows them to cross the placenta in many cases. Among the statements, that immune antibodies are mainly IgG best captures the most consistent feature across clinically significant antibodies. The other points—crossing the placenta and reacting best with antiglobulin—are true for many IgG antibodies, but the primary, defining description is that immune antibodies are predominantly IgG.

Immune antibodies are formed after exposure to an antigen, and the class most commonly involved is IgG. This is the hallmark that underpins their behavior in transfusion medicine: IgG antibodies are detected with antiglobulin (AHG) testing rather than by immediate spin, and their IgG nature allows them to cross the placenta in many cases. Among the statements, that immune antibodies are mainly IgG best captures the most consistent feature across clinically significant antibodies. The other points—crossing the placenta and reacting best with antiglobulin—are true for many IgG antibodies, but the primary, defining description is that immune antibodies are predominantly IgG.