Exam 1: HIV Flashcards
Cell Mediated Immunity (5)
- Protect against viruses, fungi, and slowly developing bacterial infections (TB)
- Immune surveillance for malignant cells
- Timing of response in delayed hypersensitivity reactions (PPD)
- Rejections of foreign grafts
- Achieves full function early in life (Helper cells fully developed by 6 yrs. of age)
HIV
Acquired cell-mediated immunodeficiency disorder, affects CD4 helper cells
Etiology
*horizontal transmission: sexual transmission, IV usage, etc.
*vertical transmission: from mother to infant
Vertical transmission is decreased with use of ZDV during pregnancy of HIV infected women; there is only 1% ocurrence of it now
HIV Pathophysiology
Retrovirus composed of RNA and enzyme reverse transcriptase
1st: Virus gains access into CD4+ cell
2nd: With in cell, reverse transcriptase causes synthesis of HIV DNA
3rd: Integrates with CD4+ cell’s DNA & virus causes CD4+ cell to make more of itself
4th: New virus assembles @ host’s cell surface as they bud through cell membrane, viruses mature and are releases, infecting other CD4+ cells
Results in cell death
HIV: Clinical Manifestations (7)
- Lymphadenopathy
- Hepatospleenomegaly
- Oral candidiasis
- Chronic or recurrent diarrhea
- Failure to thrive (not developing or growing normally)
- Developmental delays
- Parotitis (enlarged gland, gets swollen and inflamed and is very painful)
*Mainly occurs because CD4 cells can no longer do their job
HIV: Difference between children and adults (4)
- Shorter time from infection and AIDS diagnosis
- *Children can develop AIDS in less than a year if positive at birth if they don’t receive any treatment (adults can be up to 10 years)
- Signs may be physical and developmental failure to thrive
- Experience earlier opportunistic infections & greater number of bacterial infections from childhood illnesses
- Perinatally acquired – PCP (Pneumocystis Carineri Pneumonia) can occur much earlier than HIV+ adults. As a result, prophylaxis are started as early as 2 months of age.
* Adults have longer time of PCP onset
* Children can get PCP at 4-6 weeks, so start PCP prophylaxis until tests say negative if mother is HIV+!
HIV Diagnosis
ELISA or Western blot is not accurate in infants younger than 18 months
USE: HIV DNA – PCR test
- (+) results on 2 separate blood specimens (at birth, at 1-2 months, and at 4-6 months)
- 95% of infected infants diagnosed by 1-3 months
Testing for HIV exposed infant with HIV(-) screening results
If screening is negative, repeat at 1-2 months and again at 4-6 months of age.
May confirm absence of HIV infection with HIV antibody assay testing at 12-18 months of age
HIV: Clinical Staging (what are the 4 dif stages)
Stage N (infected but not symptomatic)
Stage A (mild symptoms)
Stage B (moderate symptoms)
Stage C (severe symptoms)
HIV: Immunological Staging
Stage 1 (no evidence of suppression)
Stage 2 ( evidence of moderate suppression)
Stage 3 (sever suppression)
Indicators of AIDS in Children under 13 (11)
- LIP (Lymphoid Interstitial Pneumonia); similar symptoms to asthma, a reaction the lungs have to a type of infection
- Serious bacterial infections
- PCP (pneumonia)
- CMV (citomegalovirus); not dangerous in healthy people but can cause mono in young children
* **THIS IS VERY DANGEROUS FOR SOMEONE WHO IS IMMUNOSUPPRESSED - Encephalopathy
- Wasting Syndrome
- Candidal espophagitis (can get it in lungs, GI tract, etc)
- Pulmonary candidiasis
- Herpes simplex disease
- Cryptosporidiosis (type of parasite)
- Mycobacterium Avium-Intracellulare Complex infection
CD4+ counts and HIV RNA
- Assess infected immune system’s response to therapy, risk for disease progression and need for PCP prophylaxis after 1 yr. of age
- Measure when clinically stable
- Normally higher in children than adults
- CD4+% have less measurable variability
HIV Management (4: know by heart)
- Elective Cesarean delivery before onset of labor and before rupture of membranes for women with an HIV viral load of > 1000 copies/ml.
* If less than 1,000 copies/mL then she can have normal vaginal birth - Administration of antiretroviral prophylaxis (ZDV) during pregnancy and labor and to the infant for 6 weeks after birth.
* Highly effective
* If mother is HIV+ and hasn’t been taking ZDV, then give post-exposure prophylaxis/IV infusion of ZDV during labor and delivery to diminish transmission - Complete avoidance of breastfeeding in U.S.
- In third world countries, must strictly breastfeed
- PCP prophylaxis @ 4-6 weeks of age and continues until 1 yr. of age or determined to be HIV (-) (Trimethoprine-sulfamethoxazole)
* PCP prophylaxis= Bactrim
Facts about Adolescent HIV (2)
- Percentage of total HIV/AIDS cases among 13-19 year olds has more than quadrupled from 1985 – 2004.
- More than 50% of HIV infected adolescents in the United States are unaware of their infection.
HIV: Drug Dosing for Adolescents (3)
- Based on tanner stages
* Tanner 1 and 2 – Give pediatric dosing
* Tanner 3-5 – Adult dosing - Know if it is perinatal acquired vs new onset
- -> This is because the longer you have the disease, the higher chance you have of non-adherence and then resistance can arise to all drugs in the category - Pregnancy dosing: know whether or not the medication you are giving is safe for pregnant women
UNSAFE MEDICATION= EFAVIRANEZ (causes congenital abnormalities)
CDC recommendations for HIV testing in all patients 13 to 64 years of age.
BOTTOM LINE= NEW RECOMMENDATION IS THAT EVERYONE GETS TESTED FOR HIV UNLESS THEY SAY THEY DO NOT WANT TO BE TESTED
Goals of HIV Therapy (5)
- Slowing growth of HIV
- Promoting or restoring normal growth and development
- Preventing complicating infections and cancers (there is an increased risk of lymphoma in adolescents with HIV)
- Improving quality of life
- Prolonging survival
*A lot of children with vertical transmitted HIV will be in the hospital not because of the HIV but because of lymphoma they have developed secondary to the HIV
