MicroBio 160 1st Edition Lecture 25Outline of Last Lecture I. Transmission of HIVII. How HIV enters the bodyIII. HIV Transmission TrendsIV. Modes of Transmission in AdultsV. Documented Cases VI. Routes of ExposureVII. Condom Use and HIV TransmissionVIII. Drug Use, Alcohol and HIV InfectionIX. Criminal, Deliberate and Reckless HIV TransmissionX. People who attempt to contract HIVXI. HIV Transmission Risk and Sexual behaviorsOutline of Current Lecture I. Testing for HIVII. What do CD4+ Cell Counts MeanIII. Purpose of Viral Load TestsIV. Routine TestsV. Interventions Against HIVVI. Goals of HIV TreatmentVII. Major Classes of Anti-retroviral DrugsVIII. Combination TherapyThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.IX. HAART CombinationsX. AtriplaXI. Mother to Child Transmission (MTCT)XII. Goals/ Quality of Life IssuesXIII. When is it time to Change Therapies?Current LectureTesting for HIV: Get physical exam (women: Gyn& Pap) Get key tests: CD4+ cell count & viral load Get other blood tests as needed Maximize your health support. Consider your treatment options- Early Stage: CD4+ cell counts: above 500 (Viral load: below 5,000)- Middle Stage: CD4+ cell counts: 200-500 (Viral load: 5,000-100,000)- Advanced Stage: CD4+ cell counts: below 200 (Viral load: above 100,000)- Get CD4+ cell and viral load test done every three months o Starting HIV medicines is recommended for everyone with HIV, regardless of CD4 count—talk with your healthcare provider about all the factors to consider before startingHIV medicines o In addition to CD4+ and viral load tests, general health evaluative tests are performed, such as CBC, Chemistry panel, liver and kidney function testsWhat do CD4+ Cell Counts Mean? :- Above 500 CD4+ cells: No unusual conditions likely—Emphasize good health habits andhealth care maintenance, including vaccines and nutrition- 200-500 CD4+ cells: Increased risk for shingles (zoster), thrush (candida), skin infections, bacterial sinus and lung infections, and TBo Life-threatening OIs (such as PCP (pneumocystis pneumonia, MAC (micobacteriumavium), and CMV (cytomegalovirus) are rareo Anti-HIV therapy is generally recommended when CD4+ cell counts are in the 200 to 350 range- 50-200 CD4+ cells: Increased risk for PCP and other opportunistic infectionso Preventive treatment for PCP is indicatedo If counts are below 100, consider preventive treatment for MAC, CMV and invasive fungal infections- Below 50 CD4+ cells: Increased risk for opportunistic infections, including MAC and CMVo Continue preventive medicationPurpose of Viral Load Tests:• Establish baseline: 2 tests should be taken ~ 2-4 weeks apart, then every 3-4 months. Avoid viral load tests during active infection (a cold), after a vaccination, or during flare-ups of infections (like a cold sore)—Can cause HIV levels to briefly increase, but return to normal in a few weeks• Test 3-4 weeks after starting or changing therapies—Trend of viral loads over time is the most important and not an individual result• Low, stable and decreasing viral load = good—High or increasing levels call for attentionas it may point to the failure of a regimen. Women may have a "naturally" lower viral load than men, especially in early HIV infection—Therefore, women should be aware that a viral load above 30,000 or even 60,000 might indicate a "high" viral load for them• People with "undetectable" viral load should remember that it does not mean that their HIV is gone—HIV may actually be there, but just in too small of a quantity to detectThese are routine in people living with HIV, but do not need to be done as often as CD4+ cell counts and viral load tests:- PPD Skin Test and Chest X-Rayso Tuberculosis: If you've been exposed, the PPD causes a bump to appear within several days at the site of the test—A positive or inconclusive PPD is followed up by a chest x-ray and sputum culture to determine active TB disease- Pap Smears: Women living with HIV may need to get a Pap test done more often than every 3 years based upon your health and risk factors- Anal Pap: This test can be done in the anus to look for damage caused by HPV (human papillomavirus)—High rates of anal HPV occur in HIV-positive men and women, including those who do not report having anal intercourse- Hepatitis Serology: Liver function tests can show hepatitis infectiono Other tests can be done to find antibodies to hepatitis B (HBV) and C (HCV) -- diseases that affect the liver—These tests should be done after first learning your HIV status, if you have not been tested before- Toxoplasmosis Serology: This test may be done to detect antibodies to the toxoplasmosis (toxo, cat-scratch) organism—Toxo can cause problems in the brain and central nervous system—A positive test result may help to decide on preventive therapy. Interventions Against HIV: - General Health Maintenance (lab work, eat healthy, exercise)- Supportive Therapies (complementary and alternative therapies)- Anti-HIV Treatment Strategy (meds, specialists)- Immune Therapies (enhance or inhibit immune function)- Opportunistic Infection Strategy (safe sex, food prep, good hygiene)Goals of HIV treatment: to reduce your viral load and increase your T-cell countHIV therapy should: - Prolong life and improve quality of life- Suppress HIV levels (viral load) below the limit of detection (<50 copied HIV RNA) or as low as possible for as long as possible - Optimize and extend the use of current therapy- Minimize drug toxicity, and manage side effects and drug interactionsMajor Classes of Anti-retroviral Drugs:• Reverse transcriptase (RT) inhibitors interfere with the critical step during the HIV life cycle known as reverse transcription—During this step, RT, an HIV enzyme, converts HIV RNA to HIV DNA o There are two main types of RT inhibitors- Nucleoside/nucleotide RT inhibitors or analogues (NRTIs) are faulty DNAbuilding blocks—When these faulty pieces are incorporated into the HIV DNA (during the process when the HIV RNA is converted to HIV DNA), the DNA chain cannot be completed, thereby blocking HIV from replicating in a cell- Non-nucleoside RT inhibitors (NNRTIs) bind to RT, interfering with its ability to convert the HIV RNA into HIV DNA• Protease inhibitors(PI) interfere with the protease enzyme that HIV uses to produce infectious viral particles•
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