Case Study: Immunological Malfunction

CASE STUDY 3

INSTRUCTIONS:

Read the attached Case Study – Immunological Malfunction, follow the instructions provided.

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CASE STUDY 2 QUESTION TEMPLATE

List the different immunoglobulin types and explain where they are found and what their functions are.

IgG- most common immunoglobulin present in the body. It is a vital part in the adaptive immune system because it has a variety of functions including complement activation, neutralization, cytotoxicity, opsonization, and feedback inhibiting of B-cells.

IgM- µ heavy chains. Found on the surface of B cells, function as antigen receptors. Involved in the activation pathway of complement and neutralization of the microbe.

IgA- α heavy chains. Secreted across mucosal layer in order to prevent microbes from entering the body.

IgD- δ heavy chains. Found on surface of B cells, can be found in lymph nodes and spleen. Function as antigen receptors.

IgE- ε heavy chain. Fight off parasites, also bind to allergens. Cen be found on the surface of large parasitic microbes.

Looking over this list, do Daniel’s recurrent lung infections make sense? Why?

Yes, Daniel’s infections are realistic because IgA, IgE, and IgG are responsible for protecting the body from bacterial and fungal infections. IgA protects mucosal surfaces, like the respiratory tract, which explains his numerous respiratory infections. Large parasites and fungi can easily infect the body because Daniel’s low IgE count. The biggest contributor to Daniel’s infections has to be the lack of IgG because it provides the most antibody-based responses.

What is an antigen?

An antigen is anything the body deems foreign.

What is immunoglobulin isotype switching?

It is a biological mechanism that changes a B cell's production of immunoglobulin (antibodies) from one class to another, like IgM to IgG.

How does the failure of immunological isotype switching explain the lack of IgG, IgA, and IgE in

Daniel’s blood?

Normally...