20. Diagnosis & Management of HIV

Question 1

CD4+ T cell, 10 billion viral particles are produced per day, depletes CD4+ T cells with high genetic mutation rate, evades immunity, after 4-8 weeks load peaks, then comes down which is known as the setpoint, viral load will oscillate around the set point for a number of years, CD4 count starts normal around >750ml/mm3 then drops due to the spike in the viral load CD4 count steadily drops overtime

Answer 1

natural history of HIV infection

Question 2

AIDS indicator disease or CD4+ T cells <200

Answer 2

AIDS definition

Question 3

if CD4<200 pneumocystis pneumonia infection can occur, if CD4 <100, toxoplasma encephalitis or cryptococcal meningitis with hydrocephalus due to increased intracranial pressure can occur, esophageal candidiasis may occur, disseminated histoplasmosis infection can also occur since is endemic in the midwest, tends to occur in people with lower CD4 counts, can disseminate to the lungs, liver, bone marrow, gut, meninges, if CD4 count <50, CMV retinitis can occur due to reactivation in the retina, produces oral ulcers, also can have mycobacterium avium complex infection from soil or water, disseminates to liver, spleen, bone marrow, also causes lesions in the GI tract

Answer 3

opportunistic infections of HIV

Question 4

primary CNS lymphoma can be single lesion, multiple lesions, is a B cell type lymphoma, +for CD20, associated with epstein barr virus driving the malignancy, can do EBV DNA PCR or ***, doesn’t always need biopsy, usually happens when CD4 counts <50, kaposi sarcomas is due to human herpesvirus 8, purple lesions on the palate, skin, mucosa in the gut and oral cavity, but can also be in the lungs

Answer 4

AIDS malignancies

Question 5

AIDS indicator diseases can be present even if CD4 >200, for example, kaposi’s sarcoma, lymphoma, tuberculosis, and recurrent bacterial pneumonia can occur at CD4 levels of 400, dementia occurs at CD4 >200, chronic wasting can occur at CD4>100, so the point is CD4 counts don’t have to be ultra low.

Answer 5

AIDS indicator diseases by CD4 cell count

Question 6

Shingles (zoster), thrush, oral hairy leukoplakia associated with EBV, HPV related disease like warts, anemia, low platelets, neurosyphilis, generalized lymphadenopathy

Answer 6

non-AIDS problems associated with HIV

Question 7

1.5 million new infections, 37.7 million people live with HIV, 680 thousand AIDS-related deaths, sub-saharan Africa counts for 2/3rs of the worlds cases of HIV, variably distributed across the country,

Answer 7

HIV/AIDS numbers by the world

Question 8

69% among gay and bisexual men including those that use injection drugs, 24% were among heterosexuals, 7% were among people who inject drugs, number of new HIV cases was highest among people aged 25 to 34, black and hispanic/latino population disproportionately affected

Answer 8

HIV infections by risk group

Question 9

plasma HIV viral load >750,000 cpm, CD4 count 430 (30%), HIV resistance testing shows high level resistance to non-nucleoside reverse transciptase inhibitors (NNRTIs), persons with acute HIV infection are most likely to have?

Question 10

flu or mono-like syndrome in 75%, pharyngitis, rash or headache in 50%, aseptic meningitis in 24%, oral ulcers in 15% and genital ulcers in 10%

Answer 10

acute retroviral syndrome

Question 11

starts with eclipse phase where viral load is not present for 10-12 days, HIV RNA is then present, then HIV-1p24 antigen is present and is part of the viral capsid, was added to combination assay which detects HIV-1p24 antigen and also antibody, if you are too early then RNA may only be present

Answer 11

HIV-1 infection

Question 12

initial screening is the combination Ag/ab test, if positive, order HIV-1/HIV-2 differentiation antibody assay, if negative, order HIV-1 nucleic acid testing, if positive, report as HIV-1 or HIV-2 or both positive, if HIV-1 nucleic acid testing is positive, they are positive for HIV-1

Answer 12

two-step testing for HIV-1

Question 13

endemic in west africa, modes of transmission like HIV-1, less transmission 8-10 fold, less pathogenic than HIV-1, AIDS only in 20-25%, dual infection with HIV-1 and 2 is possible

Answer 13

HIV-2

Question 14

screen all people ages 15-65, risk-based repeated screening, screen all pregnant women

Answer 14

routine HIV testing/opt-out testing

Question 15

predominant sex transmitted HIV R5 tropic uses CCR5 coreceptor, found on T cells in the mucosa of rectal tissue and cervix, all HIV viruses also use CD4 as their receptor, X4 tropic HIV virus uses CXCR4 covirus, however as R5 replicates in a given individual, can become a X4 tropic virus, CCR5 is the major viral subtype which is essential for transmission, and CXCR4 has 80% incidence in AIDS and is associated with more rapid disease progression

Answer 15

HIV strains & chemokine co-receptors

Question 16

CCR5 receptor is a receptor for B chemokines like MIP-1a, therefore delta 32 mutation does not cause human disease, homozygous patterns <1.5% have no infection, if heterozygotic 18% with delayed progression, normal progression in 80% with wild type

Answer 16

Delta 32 CCR5 mutation benefits

Question 17

HIV-1 RNA can be detected 1-3 weeks before detection of HIV antibody, high viral load >50,000 copies/mL

Answer 17

HIV-1 viral load/diagnosis/testing in acute infection