p53
Forum Guru
Topics: 51
Posts: 804
|
patients A, B, C - click on attachment - diagnoses?
Attached Files:
HIV.gif (37 KB, 36 downloads)
___________________
"Everything should be made as simple as possible, but not simpler." - Albert Einstein
|
| Isther
Forum Guru
Topics: 39
Posts: 744
|
A.- HIV latent infection
B.- acute or end stage infection
C.- HIV neg
I'm guessing so I'm ready to be embarassed...=D
___________________
Useful information for USMLE and the residency matching process at http://www.usmlematch.com
|
| p53
Forum Guru
Topics: 51
Posts: 804
|
Isther, not all your answers are correct - I will not disclose the correct answers until someone defines all 3 diagnoses correctly.
Edited by p53 on 05/29/06 - 05:13 PM
___________________
"Everything should be made as simple as possible, but not simpler." - Albert Einstein
|
| powerranger
Forum Junior
Topics: 10
Posts: 48
|
B-is HIV positive
c-not infected,
a- need to repeat the test,but I would guess he is infected too.????????????
|
| achilles
Forum Guru
Topics: 90
Posts: 1,228
|
a-not sure about a. is the patient seroconverted or some other viral infection ?
b- recently infected and represents a pt just before seroconversion.
c- negative but cant really say for sure. must do elisa after 3 months to make sure. testing for antigens is not very sensitive.
___________________
" it's not whether you get knocked down, it's whether you get up"
" i have miles to go before i sleep "
|
| achilles
Forum Guru
Topics: 90
Posts: 1,228
|
but i am also not really sure of my answers. i hope someone posts the right answers quickly
___________________
" it's not whether you get knocked down, it's whether you get up"
" i have miles to go before i sleep "
|
| AAAAA
Forum Fanatic
Topics: 156
Posts: 1,991
|
1. HIV infection negative despite p24 antigen protein positive. (Pt in 1 may need to be re-tested in 3-6 months and in next 12 months)
2. Confirmed HIV infection with 3 proteins confirmed on Western blot p24, gp120/160
3. HIV negative
___________________
seeking study partner in USMLE, Canadian MCC OSCE examination
|
| AAAAA
Forum Fanatic
Topics: 156
Posts: 1,991
|
Let me try this agaain according to the CDC gudielines.
(Also Dr. Achilles, this is the confirmatory western blot testing, )
1. HIV indetermine. Reason: CDC stated the the guidelines for interpretation of the Weastern blot testing requires antibodies against any two of the three major viral gene products (p24, gp41 or gp120/gp160)
The patient in A is strongly positive for antibodies against p24 and also p55 (not a major protein) and negative for go41 or gp120/160. SO we need to re-assess his HIV status in three-to-six months
Diagnosis: indetermine HIV status
2. Patient in B has antibodies aginst all three proteins p24, gp 41, gp 120, gp160. This confirms patient B is HIV positive
Patient C is HIV negative !
___________________
seeking study partner in USMLE, Canadian MCC OSCE examination
|
| AAAAA
Forum Fanatic
Topics: 156
Posts: 1,991
|
CDC has set specific guidelines
regarding the interpretation of results. Interpretation of Western blot results
involves reading several bands of reactivity that appear on a test strip. In
order for a result to be considered positive, reactivity to certain bands must
occur. For a result to be negative, it is necessary that no viral-specific bands
show reactivity. In some cases, reactivity will occur, but not to the specific
bands required for a positive reading. This result is called "indeterminate" and
the overall result is called inconclusive. It is possible that this occurrence
could signify early HIV infection or an early stage of seroconversion, or it
could indicate infection with HIV-2 (3). However, quite often when these bands
appear, HIV is not present (7). When a result is inconclusive, a new blood
sample is needed from the client (8). This step is required, for example, by law
in California.
___________________
seeking study partner in USMLE, Canadian MCC OSCE examination
|
| AAAAA
Forum Fanatic
Topics: 156
Posts: 1,991
|
This is the best about western blot !
Attached Files:
wblot.gif (26 KB, 13 downloads)
___________________
seeking study partner in USMLE, Canadian MCC OSCE examination
|
| AAAAA
Forum Fanatic
Topics: 156
Posts: 1,991
|
Pt A indetermine but strongly suggestive of HIV positive
Pt B HIV positive
Pt C negative
Please refer to the western blot explanation ablove
___________________
seeking study partner in USMLE, Canadian MCC OSCE examination
|
| p53
Forum Guru
Topics: 51
Posts: 804
|
yes, AAAAA is correct:
This is a Western blot (WB) assay that depicts the normal control along with three patient samples. Patient B has a positive confirmatory WB assay for HIV infection. Patient C is negative for HIV, and Patient A has an indeterminant WB that requires additional testing to determine HIV status. The WB serves as the confirmatory test for the standard enzyme immunoassay (EIA) test performed as the initial HIV test.
In a population with a low prevalence for HIV-1 (no risk factors), about 6 or 7 positive EIA test results per million tests performed will be false positives. False positive results may also occur in persons with hematologic malignancies, acute DNA viral infections, serum autoantibodies, autoimmune diseases, alcoholic hepatitis, renal failure, cystic fibrosis, multiple pregnancies or transfusions, hemodialysis, anti-HLA-DR4 antibodies, and vaccinations for hepatitis B, rabies, or influenza. Positive specimens should be repeatedly positive, with confirmation by an additional laboratory test, before reporting them as such.
The 'indeterminate' WB assays may result from repeatedly reactive true positive EIA assays on sera that are negative to WB in individuals at the early stage of HIV infection. Up to 10 to 20% of repeatedly reactive EIA assays can have an indeterminate WB assay. Indeterminate WB assays may also result from cross-reaction from infection with HIV-2, loss of core antibodies late in HIV-1 infection with loss of immunologic competence, and nonspecific antibody reactions with conditions similar to those for EIA. Indeterminate WB assays in persons who are truly HIV negative may occur from contaminating proteins in the viral lysate or from reactivity due to prior exposure to similar proteins or other viruses.
Approximately 3% of persons with indeterminate WB tests will subsequently be shown to be infected with HIV, and most of these persons will have identifiable risk factors for infection. Indeterminate results can usually be resolved by retesting the patient by EIA assay and WB. About one-third of persons with an indeterminate WB will not be repeatedly reactive by EIA assay after retesting in one month. After 6 or more months most truly HIV-1 infected persons will be positive.
___________________
"Everything should be made as simple as possible, but not simpler." - Albert Einstein
|
|
| |
| | | | | | | | | | | | |
Similar forum topics