Flashcards in Myeloma Deck (99)
What are B cells derived from?
Derived from pluripotent haematopoietic stem cells in the bone marrow
What system are B cells part of?
The adaptive immune system
B cells have a _____ role.
What is the dual role of B cells?
1. Antibody production.
2. Acting as antigen presenting cells.
What are immunoglobulins?
Antibodies produced by B cells and plasma cells
Describe the structure of immunoglobulins.
Proteins made up of (κ or λ) 2 heavy (μ, α, δ, γ, ε) and 2 light chains
What does each antibody in the body do?
Recognises a specific antigen
The type of antibody is determined by the type of ______ chain used
Of the 5 types of immunoglobulins, which are:
i) IgD, IgE, IgG.
Name the 5 immunoglobulins found in the body.
IgD, IgE, IgG, IgA, IgM
What differentiates immunoglobulins?
The type of heavy chain used
Where does initial production and development of B cells occur?
In the bone marrow
What is B cell development under the control/influence of?
What is the Ig variable element generated from?
V-D-J region recombination early in development
What are removed during B cell development?
What do immature B cells have on their surface?
What happens to immunoglobulins when they leave the surface of B cells?
They exit bone marrow, ready to meet their target
What can B cells undergo once they have left the bone marrow?
Class switching by switching heavy chains
Once B cells leave the bone marrow, and travel tot the periphery, where do they go?
The follicle germinal centre of the lymph node
What do B cells do in the follicle germinal centre of the lymph node?
They identify the antigen and improve the fit by somatic mutation, or be deleted
Lymph nodes are the site where ...
Immature B cells are exposed to antigens
Once B cells have been exposed to antigens in the lymph node, what do they do?
Either return to the marrow as a plasma cell, or circulate as a memory cell.
What is a plasma cell also known as?
A factory cell
What do plasma cells do?
Pump out antibodies
Describe the characteristic features on microscopy, of plasma cells pumping out antibodies.
* Eccentric ‘clock face nucleus’ on H+E.
* Open chromatin
Why does plasma cells pumping out antibodies look like an eccentric clock face nucleus on microscopy?
* Plentiful blue cytoplasm.
- Laden with protein.
* Pale perinuclear area.
- Golgi apparatus.
Describe the appearance of a bone marrow aspirate in multiple myeloma.
Typical ‘fried egg’ appearance, with nucleus off to one side and large, pale cytoplasm.
Healthy individuals will have a POLYCLONAL appearance
Malignancy reveals a monoclonal appearance