Systemic, immune and specific infections

Question 1

What is Sjogren’s and what is it characterised by?

what is the pathophys?

Answer 1

Autoimmune condition characterised by:
Dry eyes
Dry mouth

Caused by lymphocytic infiltration of salivary and lacrimal glands

May evolve into systemic disorder affecting exocrine function in RESP TRACT and SKIN

Question 2

classic sjogren’s triad?

Answer 2

Dry eyes
Dry mouth -> dysphagia
Arthritis (may be assoc w RA)

Question 3

Who gets Sjogren’s typically?

Answer 3

Females >90% of the time
40-60 at diagnosis.

Secondary is due to :
RA 
SLE
DM
HIV

Question 4

Risk factors for HIV

Answer 4

Multiple concurrent sexual partners

Male-male sex

Anal sex

IVDU

Uncircumscribed penises

Alcohol and drug use (risky behaviour)

Question 5

Pathophys of HIV

Answer 5

HIV binds gp120 envelope glycoprotein to CD4 receptors on helper T lymphocytes, monocytes, macrophages, and glial cells

Infected CD4 T cells migrate to lymphoid tissue where the virus replicates, producing new viruses which are released and go on to infect new CD4+ cells

As infection progresses, CD4+ cell function deteriorates and numbers are depleted, leading to decreased immunity.

Question 6

What predicts progression to AIDS with HIV?

Answer 6

Viral load (number of circulating virus particles)

Question 7

stages of HIV

Answer 7

1. Seroconversion/primary infection: HIV Ab test converts from neg to pos 2-6 weeks post exposure. +/- transient flu-like illness during this time.
2. Period of asymptomatic illness +/- lymphadenopathy: 3 months
3. AIDS-related complex: constitutional SX regarded as prodrome to AIDs (fever, weight loss, night sweats) +/- minor opportunistic infx (oral candida, leukoplakia, HZV, HSV)
4. AIDS= HIV + an indicator disease (CD4+ <200)

Question 8

What tests to diagnose HIV?

Answer 8

Serum or salivary HIV-AB by ELISA, confirmed by western blot (may be negative 1-3 weeks post exposure but should be detectable by a month)

If exposed within a month, check

• HIV-RNA
• or plasma core p24 Ag

Question 9

What cancers are more common with HIV?

Answer 9

Lymphomas
Kaposi’s sarcoma
Anal cancer

Question 10

What is the normal CD4 T cell count? What number defines AIDs?

Answer 10

normal >500

AIDs<200

Question 11

What 2 pulmonary infections can be life threatening with HIV?

Answer 11

Tb
Pneumocystis pneumonia (PCP)

Question 12

Treatment for HIV

Answer 12

Antiretroviral therapy
- suppresses viral replication to prevent viral infection of CD4+ cells and reconstitutes cell-mediated immunity

Immune reconstitution Inflammatory response (HAART) - reconstitutes CD4 counts. Can paradoxically worsen SX initially!

Monitor viral load (should be <200RNA copies/ml)

Question 13

What co-infections do you screen for w HIV?

Answer 13

Anal, throat, vaginal, urethral swabs:

• culture
• PCR (chlamydia trachoma, neisseria gonorrhoea, HSV)

Bloods:

• syphillis
• Hep A,B,C
• HIV

Question 14

Classic opportunistic infections with AIDs

Answer 14

□ Cerebral toxoplasmosis (almost only w HIV)
□ CMV retinitis (almost only w HIV)
□ Cryptococcal meningitis
□ Pneumocystis pneumonia (PCP)
□ Mycobacterium avid complex (MAC) infections (almost only w HIV)