38: HIV/AIDS - Bennett Flashcards
define AIDS
A secondary immunodeficiency syndrome resulting from HIV infection and characterized by opportunistic infections, malignancies, neurologic dysfunction and a variety of other syndromes
describe the HIV virus
- HIV is a human retro-virus of the lentivirus group
- HIV-1 most common cause of aids in the world (w. hemisphere, europe, central, south, & east africa)
- HIV-2 more related to the simian retro viruses (less common & less pathogenic mostly isolated in west africa)
what part of the immune system is compromised?
the immune defect is quantitative and qualitative deficiency in the thymus derived t-lymphocytes (t4 population)
- this set of cells is defined phenotypically by the presence of cd4 surface molecules, which is the cellular receptor for HIV
- virtually any cell with this receptor can be infected
- HIV binds specifically and with a HIGH AFFINITY
HIV testing options
Elisa first, follow up with western blot and PCR if positive
Elisa
This is the first step of an HIV test. This test detects the presence of HIV antibodies in the blood. If the test is negative then the person is determined not to be HIV infected and testing stops there. If the test is positive the second step of the test is run to confirm the positive results of the first step.
Western Blot
This test is used to confirm the positive Elisa test results. The Western Blot test detects specific protein bands that are present in an HIV infected individual. In combination with a positive Elisa, a positive Western Blot is 99.9 percent accurate in detecting that HIV infection has occurred.
HIV PCR
The HIV PCR test detects specific Deoxyribonucleic Acid (DNA) and Ribonucleic Acid (RNA) sequences that indicate the presence of HIV in the genetic structure of anyone HIV infected. After HIV infection occurs, RNA and DNA from the HIV virus circulates in the blood. The presence of these DNA and RNA “pieces” indicates the presence of HIV virus.
clinical manifestations
group I acute infection = acute mononucleosis like syndrome characterized by fever, macular or papular rash, malaise, and lymphadenopathy
group II asyptomatic infection = chronically infected, serology positive, virus culture positive, no clinical manifestations (latent state)
group III persistent genralized lyphadenopathy = palpable enlarged (lymph nodes >1cm.) at two or more extrainguinal sites persisting for more than 3 months, all test results are positive
group IV other diseases = subgroup a constitutional disease subgroup b neurological disease subgroup c secondary infectious disease subgroup d secondary neoplasm subgroup e other conditions
CD4 count and HIV copies are ______ related
inversely
key CD4 count
under 400 starts to look bad
opportunistic infections at CD4 350 level ***
herpes simplex virus TB oral/vaginal thrush herpes zoster (shingles) non-hodgkins lymphoma KAPOSI SACRCOMA
opportunistic infections at CD4 200 level ***
pneumocystis carinii penumonia (PCP pneumonia/ PNEUMOCYSTIC JIROVECI PNEUMONIA)
candida esophagitis
bacillary angiomatosis
opportunisitic infections at CD4 100 level ***
cryptococcal meningitis AIDS DEMENTIA toxoplasmosis encephalitis progressive multifocal leukoencephalopathy WASTING SYNDROME cryptosporidium diarrhea
opportunistic infections at CD4 50 level
mycobacterium avium
cytomegalovirus infection
primary neutrophic manifestations
Encephalopathy 90% Meningitis 10% Myelopathy 12% Myopathy Neuropathy 10-50%
secondary lymphotrophic manifestations
Metabolic and toxic
Neoplasm’s
Opportunistic
Vascular complications
describe encephalopathy
aka AIDS dementia complex
Loss of concentration, forgetfulness, slow thoughts
Motor symptoms: loss of balance , leg weakness,
Parkinson’s like: tremors, muscle rigidity, slowed movements
Exam (hyperreflexia, babinski’s, gait ataxia)
treatment neuropathies
Desipiramine (25-250mg.) @bedtime
Amytriptyline (25-150mg.) @bedtime
Mexilitine (600 to 1200mg/day)
Gabapentin (300 to 3600 mg/day)
