A patient is producing an antibody isotype that is composed of a dimer held together by J protein and is secreted into his saliva. Which of the following isotypes is being produced by this patient?
A) IgA
B) IgD
C) IgE
D) IgG
E) IgM

Question

Quizplus · Accepted Answer

IgA is the only isotype that forms a dimer held together by a J chain and is secreted into mucosal secretions such as saliva. IgD, IgE, IgG, and IgM do not form dimers held together by J chains.

A Patient Is Producing an Antibody Isotype That Is Composed