What are macromolecules that elicit the formation of immunoglobulins called?

The macromolecules that elicit the formation of immunoglobulins are best described as immunogens. Immunogens are specific types of antigens that are capable of inducing an immune response and triggering the synthesis of antibodies.

While antigens refer to any substance that can be recognized by the immune system and bind to specific antibodies, not all antigens are necessarily immunogenic. For example, haptens are small molecules that can become immunogenic only when they are attached to a larger carrier molecule. Therefore, while the term "antigen" is broadly applicable, immunogens specifically emphasize the capability of a substance to provoke an immune response resulting in the production of immunoglobulins.

Pathogens, on the other hand, are microorganisms that can cause disease, and while many pathogens can act as immunogens, the term does not specifically encompass macromolecules in a general sense.

Thus, immunogens are the most precise choice for describing those macromolecules that lead to the production of immunoglobulins.