Lecture 31 - fever

Question 1

Causes of lymphadenopathy

Answer 1

• Proliferation of lymphocytes in response to a local infection
• proliferation of malignant cells that have metastasised to the node by lymphatic spread
• proliferation of malignant lymphocytes
• inflammation within nodes resulting from killing of lymphocytes infected by a virus (e.g HIV)

(bacteria dont infect lymphocytes)

Question 2

Herpes Viruses

Answer 2

Dna virus
-cause acute infection, and then get a persistent infection for rest of life (chronic infection) and a latent infection with reactivation

• Cold sores
• Varicella zoster virus (chicken pox)
• EBV - glandular fever

Question 3

Glandular fever

Answer 3

• Epsinibar virus
• causes infection in lymphocytes and enlarged lymph nodes
• then infection becomes under control, but not eliminated
• virus replicates in lymph nodes, and are released in lymph nodes in mouth and into saliva
• then spreads to next person, gets into their tonsils and then spreads
• when you acquire this as a child is not too bad, but when get this as an adult is worse - are unwell for a while

-incubation for about a month

Symptoms - fever, sore throat, cervical adenopathy, malaise, fatigue.

Take blood sample - white cells - lots of cytotoxic lymphocytes going to the site of infection to kill the viral producing cells

• abnormal liver function tests
• also have monospot test (antibodies stick to the virus)
• also have a test that detects antibodies sticking to other stuff e.g it binds to guinea pig, sheep, horse RBCs - something on the surface of these RBCs that will stic to these - heterophile antibodies (dont actually attatch to EPV).

Question 4

Acute HIV infection

Answer 4

3-6 weeks previous exposure to HIV infection

• glandular fever like illness
• can look for antibodies in blood against HIV infection

Question 5

HIV pathogenesis

Answer 5

Helper T cells get infected by HIV, and a then t killer cells kill the t cells

• however if not controlled then lots of HIV will be produced
• can never be fully cured because the only cells the immune system can recognise are the ones that have replicating virus in them and there are many more cells that are effected
• no proof reading errors so does lots of erros made to generate a wide range of mutant viruses
• HIV also evolves to evade a persons immune system
• Lots of t helper cells die, and cannot make enough so people are very immune defficient

Question 6

Testing HIV

Answer 6

Elisa test - tests for HIV in blood (uses test tubes with hiv antigen, then serum sample is added, then an anti-human antibody with adherent enzyme added and if this attatches to serum antibody , then reagent added adn if this cleaves the enzyme then results in colour change)

• detect antibodies in blood against HIV
• detect HIV genome in blood - with PCR

Question 7

Other illnesses you can get with AIDS

Answer 7

-pneumonia, oral canditis,

Kaposis sarcoma

Question 8

no vaccines yet

Answer 8

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