3 - Immune Disease Flashcards
Virulence refers to:
the capacity of a virus to cause severe disease
Endemic refers to:
disease with relatively high but constant rates of infection in a particular population
Epidemic refers to:
the number of new infections in a particular population greatly exceeds the number usually observed
Define the following:
Direct Transmission
Vertical Transmission
Indirect Transmission
Direct: human to human via contact
Vertical: mother to child in utero
Indirect: via vector
What are the four stages of infection?
Incubation
Prodromal
Invasion
Convalescence
Bacteria are prokaryotes, meaning:
They are unicellular organisms
They have no nuclei, mitochondria or other membrane bound organelles
Gram negative bacteria (do/do not) retain violet dye in a gram stain
Do not
Gram ______ bacteria contain a lipopolysaccharide coat that is also known as _____
Negative
Endotoxin
What’s the difference between endotoxin and exotoxin?
Exotoxins are produced during bacterial proliferation
Endotoxins are contained in the cell walls of GRAM NEGATIVE bacteria and are released during lysis or destruction of the bacteria
Bacteria that produce endotoxins are called _______
pyrogenic bacteria
What are some of the potential actions of endotoxins?
- diffuse vasodilation with hypotension
- activation of the coagulation cascade, leading to DIC
- release of TNF-A, resulting in wide spread inflammation
Most bacteria secrete a variety of proteases. Why?
Defend the pathogen from the immune system by digesting components of plasma systems (including clotting, complement, fibrinolysis)
Weaken surrounding connective tissue, allowing invasion
Infection with a fungus is called:
mycosis
Some viruses have a protective envelope over their capsid. Where does this envelope come from?
The plasma membrane from the previously infected cell!
Which types of bacteria have a phospholipid bilayer outer membrane?
Gram negative ONLY
The primary surface receptor on HIV is the envelope glycoprotein _____, which binds to _____ molecules found mostly on the surface of _____ cells
gp120
CD4
T-helper
The major immunologic finding in AIDS is the a striking decrease in the number of ______ cells
CD4+ Th cells
Children with HIV are at increased risk of _______
coronary artery disease
What is infectious mononucleosis?
an acute viral infection of B cells
What is the incubation period of IM?
30-50 days!
What is the classic triad of mono symptoms?
fever
pharyngitis
lymphadenopathy of cervical lymph nodes
The common feature of all forms of leukemia is:
uncontrolled proliferation of leukocytes, causing overcrowded bone marrow and a decrease in functional normal hematopoietic cells
Leukemia is a _____ and _____ disorder
accumulation
proliferation
What is the difference between precursor and peripheral lymphocytes?
precursor = immature
peripheral = mature
What is the most common form of leukemia in children?
Acute Lymphocytic Leukemia (ALL)
What are the most common types of leukemia in adults?
chronic lymphocitic leukemia (CLL)
Acute myelogenous leukemia (AML)
90% of lymphoid neoplasms originate from _____
B cell progenitor disorder
In a patient with ALL, you would expect an increase in which kinds of white blood cells?
lymphoblasts
(T-cell, B-cell)
In a patient with AML, you would expect an increase in which white blood cells?
Non-lymphoblast
(everything but T and B cell)
Why does treatment for one cancer often lead to AML?
Drugs that cause bone marrow depression predispose individuals to leukemia
Why is CNS involvement common in leukemia?
Either from leukemic infiltration or cerebral bleeding
What is the 5-year survival rate for adult leukemia?
38%
What is the most common adult cancer?
Chronic Lymphocytic Leukemia
The _____ chromosome is present in ____% of CLL patients
Philadelphia
95
CLL involves malignant transformation and progressive accumulation of _____
monoclonal B cells
(rarely t cells)
What is it about CLL that makes it chronic, and not acute?
the cells that accumulate in the marrow don’t interfere with normal blood cell production that much
The major pathophysiologic deficit in CLL is:
the failure of B cells to mature into plasma cells that synthesize immunoglobulins
The most significant effect of CLL is
suppression of humoral immunity and increased infection with encapsulated bacteria
Lymphadenopathy is caused by four kinds of disease:
- Neoplastic
- Immune/Inflammatory
- Endocrine
- Lipid storage
There are two types of lymphoma:
Hodgkins
Non-Hodgkins
There are three types of non-Hodgkin lymphoma:
B-cell neoplasms
T-cell neoplasms
NK neoplasms
Hodgkin Lymphoma is indicated by the presence of which cells?
Reed-Sternberg B cells
Discovery of an ______ is often the initial sign of HL
asymptomatic mediastinal mass
What causes the symptoms associated with Hodkins?
the Reed-Sternberg cells secrete cytokines and growth factors that induce infiltration and proliferation of inflammatory cells
What is the cure rate for Hodgkins?
75%
What age range is associated with Hodkins?
Non-Hodgkins?
Early 20s and 60s
Middle Age
What is Burkitt Lymphoma?
B-cell non-Hodgkin lymphoma
fastest growing human tumor
Which virus is associated with almost all cases of Burkitt Lymphoma?
EBV
Lymphoblastic lymphomas are _____ lymphomas arising from _____ cells
NHL
T cells
It’s easy to mistake a disease process for a lymphoma. When differentiating, an important distinction is:
lymphomas usually involve localized lymphadenopathy
What has to happen for a plasma cell to be made?
A B cell has to be presented with an antigen and stimulated with cytokines from T helper cells
undergoes proliferation and differentiation into an antibody-producing plasma cell
When do plasma cells become malignant?
During development, plasma cells are designed to secrete IgM, or are rearranged to irreversibly switch to IgG, IgA or IgE
This rearrangement is when some cells may become malignant
A common characteristic of plasma cell tumors is:
secretion of complete or partial immunoglobulin molecules
What is multiple myeloma?
clonal plasma cell cancer causing tumor cell masses in the bone marrow
Multiple Myeloma causes malignant plasma cells that:
produce abnormal amounts of one class of immunoglobulin
USUALLY IgG!
Why does Multiple Myeloma cause bone lesions?
Malignant plasma cells return to the bone marrow and adhere
they result in osteoclast activation, and osteoclasts begin reabsorbing bone
Multiple myeloma results in ____ and _____
bone lesions
hypercalcemia
What is amyloidosis?
When antibody proteins stick together and deposit in peripheral nerves and organs
Why does multiple myeloma cause renal failure?
Produces an intense amount of abnormal protein in the blood, which puts strain on the kidneys and causes increased viscosity
What is the leading cause of death from MM?
Infection
How does the pathogenesis of Waldenstrom macroglobulinemia differ from MM?
WM arises from plasma cells that have undergone rearrangement, but NOT class switch. So they still primarily secrete IgM
What is hypersplenism?
When splenomegaly leads to overactivity of the spleen
Splenic rupture is a complication associated with which disease?
Mono
Beta Thalassemia results in both hypochromic-microcytic anemia and iron overload. How?
Reduced beta globin synthesis leads to abnormal erythroblasts, most of which die in the bone marrow
the ones that do survive are released into the blood stream and don’t live very long, lysing and releasing iron
The body can sense that Hgb levels are low, so it starts absorbing more iron, but the marrow isn’t producing enough cells to use that iron, so it builds up in the body
Why is B thalassemia more common?
Depending on which trait is inherited, alpha thalassemia is usually either extremely mild or lethal enough to cause stillbirth
What is usually the cause of death for people with B thalassemia?
Hemochromatosis
There are two reasons kids with leukemia may run a fever:
- Infection
- Hypermetabolism from rapid growth and destruction of leukemic cells
What is the most common cause of non-hodgkins lymphoma in children?
Burkitt’s
