Lecture 31: Fever and Lymphadenopathy

Question 1

Causes of lymphadenopathy?

Answer 1

• Proliferation of lymphocytes in response to local infection
• Proliferation of malignant cells that have metastasised to the node by lymphatic spread (not often associated with fever)
• Proliferation of malignant lymohocytes (not often associated with fever)
• Inflammation within the nodes resulting from killinh of lymphocytes infected by a virus

Question 2

Bacterial and viral infections og lymph nodes?

Answer 2

Bacterial

• Staphylococcus aureus
• Mycobacterium tuberulosis

Viral

• Epstein Barr Virus (EBV)
• Cytomegalovirus (CMV)
• Human immunodeficiency Virus (HIV)

Question 3

Glandular fever is caused by?

Answer 3

Infectious mononucleosis has two causes, both are Herpes viruses. Incubation of 4-6 weeks and illness lasts 1-2 weeks generally = fever, sore throat, cervical adenopathy, malaise, fatigue

EBV - most common causative agent of glandular fever

CMV - less common, less severe glandular fever-like illness

Recovery occurs but persistant salivary excretion of EBV

Question 4

Lab diagnosis of acute EBV infection? (CMV?)

Answer 4

• Lymphocytosis (>50% of WBC)
• Atypical lymphocutes (>10% of lymphocytes)
• Abnormal LFT

BUT, the main test is done is the monospot test - Detects “heterophile” anitbodies which bind to guinea pig/sheep/horse RBC but NOT to EBV!

or can do a specific EBV serology

(for CMV you need to do a specific test for the presence of antibodies IgM/G to CMV)

Question 5

Describe an ELISA test?

Answer 5

Enzyme Linked Immunosorbent Assay

1. HIV antigen stuck to base of ELISA wells
2. Serum sample added - antibody in serum attaches to HIV antigen
3. Anti-human antibody with adherent anzyme added - attaches to serum antibody
4. Reagent added - cleaved by enzyme on anti-human antibody = results in colour change

Question 6

Recap HIV knowledge

Answer 6

Seroconversion illness - looks like glandular fever illness early after infection at 4-6 weeks.