Disease of the Immune System Path Lecture

Question 1

What is X-linked agammaglobulinemia (XLA), or Bruton disease?

Answer 1

failure of B cell maturation, absence of antibodies; caused by mutations in BTK, which encodes a tyrosine kinase required for maturation signals from the pre-B cell and B cell receptors

Question 2

What is Selective IgA deficiency?

Answer 2

failure of IgA production; cause unknown

Question 3

When would ferritin levels increase?

Answer 3

acute-phase reactant so it increases during infection

Question 4

What is the seroconversion rate for accidental exposure to HIV?

Answer 4

Seroconversion has been documented with a rate of about 0.3% per accidental exposure

Question 5

What is the seroconversion rate for accidental exposure to Hep-B?

Answer 5

By comparison, the rate of seroconversion after accidental exposure to hepatitis B–infected blood is about 6% to 30%.

Question 6

What glycoproteins does HIV use for binding to host T CD4 cells?

Answer 6

gp120 and gp41

Question 7

What are gp120 and gp41 used for in HIV infection?

Answer 7

gp120- CD4 binding

gp41- membrane penetration

Question 8

What does HIV do to host T cells?

Answer 8

lyse them and kill them

Question 9

Why would subsequent infection in those already infected with HIV promote progression of the disease?

Answer 9

Release of inflammatory mediators like IL-1, TNF-a, and IL-6 that are released following subsequent infection are involved in boosting the infectious nature of HIV somehow

Question 10

Which cell in the mucosal surface is thought to be instrumental in transmitting HIV to CD4 T cells?

Answer 10

Dendritic Cells present the virus to T cells

specifically langerhan’s cells

Question 11

What is another major player in HIV infection?

Answer 11

Macrophages

Question 12

Why are macrophages involved in HIV?

Answer 12

They are resistant to the cytotoxic effects and can harbor the virus for long periods of time.

These are also thought to be responsible for transmitting to the brain (and to microglial cells)

Question 13

What happens to T cell levels and virus levels once an infection is initiated (timeline of 10 or until AIDS progression)?

Answer 13

Acute phase infection which is concurrent with flu-like symptoms with an abrupt rise in virus that begins to kill off T cells. Then the virus goes into a latency period, T cells recover briefly, and slowly the virus begins to kill T cells until AIDS progression

Question 14

What T cell count is used for AIDS diagnosis?

Answer 14

less than 200/ul CD4+ T cells. Common in the South still.

This significantly increases infection risk.

Question 15

Primary HIV infection typically manifests as:

Answer 15

A self-limited illness, with high viremia and only modest T cell reduction

Question 16

What are some common protozoal and helminthic infections associated with HIV?

Answer 16

•Cryptosporidiosis
(enteritis=diarrhea)

•Pneumocystosis
(pneumonia or disseminated infection)

Pneumocystis jirovecii is a yeast- like fungus of the genus Pneumocystis

•Toxoplasmosis (pneumonia or CNS infection)

these are all opportunistic and more common in AIDS than HIV

Question 17

What are some common fungal infections associated with HIV?

Answer 17

• Candidiasis (esophageal, tracheal, or pulmonary)
• Cryptococcosis (CNS infection) •Coccidioidomycosis (disseminated)
• Histoplasmosis (disseminated)

Question 18

What are some common bacterial infections associated with HIV?

Answer 18

•Mycobacteriosis (“atypical,” e.g., Mycobacterium avium-intracellulare,disseminated or extrapulmonary; Mycobacterium
tuberculosis, pulmonary or extrapulmonary)
•Nocardiosis (pneumonia, meningitis, disseminated

Question 19

What are some common viral infections associated with HIV?

Answer 19

• Cytomegalovirus (pulmonary, intestinal, retinitis, or CNS infections)
• Herpes simplex virus (localized or disseminated infection)
• Varicella-zoster virus (localized or disseminated infection)
• Progressive multifocal leukoencephalopathy

Question 20

What are some common neoplasms associated with HIV?

Answer 20

• Kaposi sarcoma
• Primary lymphoma of brain
• Invasive cancer of uterine cervix

Question 21

What are some other complications associated with HIV?

Answer 21

Wasting syndrome, neurological complications, kidney disease

Question 22

What is Wasting syndrome?

Answer 22

Aggressive treatment regimens have reduced the number of cases of wasting syndrome. It’s defined as a loss of at least 10 percent of body weight, often accompanied by diarrhea, chronic weakness and fever.

Question 23

Neurological complications with HIV.

Answer 23

Although AIDS doesn’t appear to infect the nerve cells, it can cause neurological symptoms such as confusion, forgetfulness, depression, anxiety and difficulty walking. One of the most common neurological complications is AIDS dementia complex (less common now with heart therapy), which leads to behavioral changes and diminished mental functioning.

Question 24

Kidney disease associated with HIV.

Answer 24

HIV-associated nephropathy (HIVAN) is an inflammation of the tiny filters in your kidneys that remove excess fluid and wastes from your bloodstream and pass them to your urine. Because of a genetic predisposition, the risk of developing HIVAN is much higher in blacks.

still very common in patients

Question 25

A HIV patient presents with altered mental status. It is determined that they have primary CNS lymphoma. What virus is this most likely related to?

Answer 25

EBV