Question

There are infections in which antibodies directed against the infectious agent react with normal host cells. For example, in atypical pneumonia caused by Mycoplasma pneumoniae, antibodies to heart, lung, brain, and red blood cells may be formed. The antibodies to red blood cells (called cold agglutinins) can cause autoimmune hemolytic anemia. What is this phenomenon called?

Anergy
Apoptosis
Molecular pathogenesis
Molecular mimicry
Antigenic variation

Answer 1

The phenomenon described is called molecular mimicry, where antibodies cross-react with self-antigens due to structural similarities with pathogen antigens. An example is the formation of antibodies to red blood cells in atypical pneumonia caused by Mycoplasma pneumoniae, leading to autoimmune hemolytic anemia.

Step-by-step explanation:

The phenomenon described, in which antibodies react with normal host cells, is called molecular mimicry. In this process, antibodies or T-cell receptors that are initially raised against the nucleic acids or proteins of microorganisms later cross-react with self-antigens due to structural similarities between pathogen antigens and self antigens. For example, in atypical pneumonia caused by Mycoplasma pneumoniae, the antibodies to red blood cells can cause autoimmune hemolytic anemia.