Immunity - Midterm 1 Flashcards
What does the term Virulence refer to?
The capacity to cause severe disease – how hard is it to treat microorganism, how likely is someone to die from this disease.
Type 1 allergy anaphlactic?
-Emergency situation (2 - 3 min to develop)
Difficulty breathing
Wheezing, stridor
↑ heart rate - ↓ blood pressure
*corticosteroids- decrease swelling
T-cell deficiency can be associated with?
Viruses (varicella herpes, cytomegalovirus)
o Fungi
o Yeasts (Candida, Histoplasma)
o Atypical microorganisms (Pneumocystis carinii - now known as Pneumocystis jirovecii)
What kind of deficiency is ADA, and what does it result in?
Is a combined deficiency (affecting both B + T cells)
-Results in the accumulation of toxic purines
What are the developmental stages of AIDS? What occurs during each phase?
Stage 1 – Acute
Occurs about 1 to 2 weeks after initial infection. During this stage, the virus undergoes massive replication. Patients may be asymptomatic or have a flu-like symptoms
2.) Stage 2 – Asymptomatic HIV
During this stage, chronic signs or symptoms are not present. T-cell count may be used to monitor progression of the disease. With the patient’s own resistance and drug therapy, this stage can last for 10 to 12 years or longer. - person feels asymptomatic, but virus is proliferating in lymph nodes
3.) Stage 3 – Symptomatic HIV
This stage has two phases: early and late. When the T-cell count falls below 200 cells per cubic millimeter of blood, it is the late phase. This stage of HIV is defined mainly by the emergence of opportunistic infections and cancers to which the immune system normally helps maintain resistance.
Stage 4 – Advanced HIV
A T-cell count of 50 cells per cubic millimeter or less represents advanced HIV. With the onset of this stage, patients are at the highest risk for opportunistic infections and malignancies - Parasitic, fungal, bacterial, viral infections, and neoplasms
-Treated with “cocktail” (3 or more drugs)
Endotoxins (when are these released) Vs Exotoxins?
Exotoxins – secreted toxins - elicit the production of antitoxins - a toxin released by a living bacterial cell into its surroundings.
Endotoxins - also known as pyrogens - cell wall released during cell death– can’t prevent the toxic effects – causes the inflammatory process to be activated
Type 3 hypersensitivity ? (immune complex)
-Reaction from antigen-antibody complexes (Not organ specific)
- Type III antibody binds to antigen in body or in fluid, then complex is deposited onto tissue
- IgG or IgM bind to antigen – form complexes deposited in various tissues = target tissues and destroys them
- =arthritis, Lupus, serum sickness
- 1- 3 weeks
Primary (congenital) immune deficiency Vs Secondary (acquired) immune deficiency?
Primary (congenital) immune deficiency – a genetic defect
Secondary (acquired) immune deficiency – caused by another condition (ie. Cancer, aging)
Autoimmunity Vs Alloimmunity?
Autoimmunity – disturbance in the immunological tolerance of self-antigens T-cells damages tissues in self
Alloimmunity – immunological reactions to transfusions, transplants, or fetus during pregnancy
Type 4 hypersensitivity? What do the antigens do here?
-Delayed response
-Antigen sensitizes cell to release cytokines that activate macrophages, the macrophages remove cells, because of this the reaction is delayed
-Continued exposure to the irritant makes the reaction worse each time the person is exposed
-Reaction occurs 1 - 3 days after exposure
Ex. latex, Nickle, poison ivey
Primary Vs Secondary Immunodeficiency?
-Primary – born with it – congenital – defect – part of the immune system is either absent or not functioning properly
-Secondary or acquired deficiencies more common - immune system is compromised due to an environmental factor (HIV, severe burns, chemotherapy, radiation, diabetes, malnutrition)
What is the window period for the AIDS infection to appear as antibodies?
4-7wks
What are the normal rates of infection for adults and children?
Preschool-age children: 6-12 infections a year
Adults: 2-4 infections a year
Portal of entery?
How the disease enters the body
Inhalation – ingestion – bites
What are community and nosocomial infections?
Community-acquired – influenza – (Hospital acquired, Health care acquired)
Nosocomial – infection exists in a hospital - central lines, catheters, pneumonia – interchangeable with hospital acquired
What is Type 4 hypersensitivity?
-It is mediated by T - cells and don’t involve antibodies - takes days to weeks for oneset to occur
Tc cells – attack and destroy cells directly. Damage happens from cell being destroyed.
o Th1 and Th17 cells – produce cytokines that recruit and activate phagocytic cells (macrophages).
What is serum sickness? What are some symptoms? Potential cause?
-Type 3 hypersensitivity
-Immune complexes formed in blood and deposited on tissue this typically affects blood vessels, joints, and kidneys causing damage
Symptoms include:
* Fever
* Enlarged lymph nodes
* Rash
* Pain at sites of inflammation
Can be caused by IV administration of other antigens like medication
