Question

An antibody titer was done on a patient and antibodies ___________ were found to be in large numbers compared to IgG. This tells us that the patient had ___________ infection.

Answer 1

Answer:

An antibody titer was done on a patient and antibodies __IgM_________ were found to be in large numbers compared to IgG. This tells us that the patient had __acute_______ infection.

Explanation for the correct answer:

Antibodies are the proteins which are produced by the response of the body immune cells mostly the B lymphocytes in response to antigenic stimulation and are responsible for the immune response of the body on exposure to an antigen.The antibodies bind with the invading antigen and cause the formation of antigen-antibody complexes which are destroyed by the white blood cells /dendritic cells /macrophages thereby protecting the body against the infection/ antigenic invasion.

The antibody titer test is a blood test performed to detect the presence of antibodies in the blood.The antibody level estimation in the antibody titer blood test is performed in cases of infections, post vaccination states to see for presence of antibodies, in autoimmune diseases to check for presence of autoantibodies and to study the response of the disease to the therapy and the progression of the disease.The results of the antibody titer test is generally expressed as a ratio.

The production of the antibodies in response to the antigenic stimulation by the immune system is explained in the flowchart below.

An acute infection ------exposure to pathogenic antigen------- stimulation of the immune response by the immune cells---- generation of immunoglobulin M in acute infection----- persistence of antigenic stimulation----- production of immunoglobulin G----detection of IgG antibodies in antibody titer test  4-6 weeks after the antigenic stimulation by the immune system------ infection control.

Interpretation of the antibody titer in infection

As the antibody IgM first appears in an acute infection,its presence in higher ratio/large numbers  in antibody titer test as compared to IgG indicates acute infection.

Acute infection----- antibody IgM level elevation.

Chronic infection/ late infection/ past infection---- antibody IgG level elevation.

In an acute infection, the immunoglobulin M is the first antibody to rise and increase in the blood which is detectable in large numbers by antibody titer test as early as two to four weeks after exposure to the acute infection.The immunoglobulin G take a longer time to increase in the blood and are detectable in the antibody titer test as late as four to six weeks after the acute infection.

As IgM antibodies are detected in the antibody titer test in large numbers as compared to IgG antibodies in acute infection; hence this is the correct answer.