HIV AIDS diagnostic study of choice: Difference between revisions
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===Screening Immunoassays=== | ===Screening Immunoassays=== | ||
There have been five generations of enzyme immunoassays(EIAs) that use different [[antigen] compositions and detection chemistries to give precise and high volume samples for laboratories. | There have been five generations of enzyme immunoassays(EIAs) that use different [[antigen] compositions and detection chemistries to give precise and high volume samples for laboratories.<ref name="pmid30487166">{{cite journal| author=Parekh BS, Ou CY, Fonjungo PN, Kalou MB, Rottinghaus E, Puren A | display-authors=etal| title=Diagnosis of Human Immunodeficiency Virus Infection. | journal=Clin Microbiol Rev | year= 2019 | volume= 32 | issue= 1 | pages= | pmid=30487166 | doi=10.1128/CMR.00064-18 | pmc=6302353 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=30487166 }} </ref> | ||
*First Generation Assay: It used antigen [[lysate]] preparations to detect [[antibodies]]; however due to high false positivity it was replaced by highly specific immunoassays and [[western blot]] techniques. | *First Generation Assay: It used antigen [[lysate]] preparations to detect [[antibodies]]; however due to high false positivity it was replaced by highly specific immunoassays and [[western blot]] techniques. | ||
*Second Generation Assay: Proteins derived from [[Immunodominant regions]](IDR) of HIV-1 [[proteins]] and gp36 of HIV-2 were used to increase [[sensitivity]] and decrease false positivity. | *Second Generation Assay: Proteins derived from [[Immunodominant regions]](IDR) of HIV-1 [[proteins]] and gp36 of HIV-2 were used to increase [[sensitivity]] and decrease false positivity. | ||
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief:
Overview
Diagnostic Study of Choice
Study of choice
Fourth generation test(ELISA/ELI/MEIA/ELFA/ECLIA) have high sensitivity; therefore they are used as confirmatory test. These test can detect both p24 antigen as well as HIV antibodies.
Screening Immunoassays
There have been five generations of enzyme immunoassays(EIAs) that use different [[antigen] compositions and detection chemistries to give precise and high volume samples for laboratories.[1]
- First Generation Assay: It used antigen lysate preparations to detect antibodies; however due to high false positivity it was replaced by highly specific immunoassays and western blot techniques.
- Second Generation Assay: Proteins derived from Immunodominant regions(IDR) of HIV-1 proteins and gp36 of HIV-2 were used to increase sensitivity and decrease false positivity.
- Third Generation Assay: Detection of Ig G antibodies by using antigens such as gp160 derived from HIV-1 group M, recombinant p24, recombinant peptide from HIV-2 gp36 IDR and synthetic peptide from HIV-1 group O. It also detected HIV-1 IgM to further reduce window period.
- Fourth Generation: It detected both antigen and antibodies at the same time using fully automated chemiluminescent microparticle.
- Fifth Generation: It used multiplex format to detect distinguished p24 antigen of HIV-1 and HIV-2.
Confirmatory Immunoassays
The specimens that were reactive with EIAs need to be retested with more specific confirmatory test which is Western Blot using a gradient purified HIV lysate, electrophorese and suffused onto nitrocellulose strips. For WB to be considered positive, it has to contain antibodies reactive to p24 antigen and envelope glycoproteins.
Rapid Testing Assays
The rapid tests is completed in about 20-30 mins making it ideal in primary care and mobile clinics. Non-laboratory staff can perform these test as it require finger prick blood sample or oral fluid. Although these are less sensitive than EIAs; however, their specificity is higher.
The comparison of various diagnostic studies for [disease name]
| Test | Sensitivity | Specificity |
|---|---|---|
| Test 1 | ...% | ...% |
| Test 2 | ...% | ...% |
[Name of test with higher sensitivity and specificity] is the preferred investigation based on the sensitivity and specificity
Diagnostic results
The following finding(s) on performing [investigation name] is(are) confirmatory for [disease name]:
- [Finding 1]
- [Finding 2]
Sequence of Diagnostic Studies
The [name of investigation] must be performed when:
- The patient presented with symptoms/signs 1, 2, and 3 as the first step of diagnosis.
- A positive [test] is detected in the patient, to confirm the diagnosis.
OR
The various investigations must be performed in the following order:
- [Initial investigation]
- [2nd investigation]
Name of Diagnostic Criteria
It is recommended that you include the criteria in a table. Make sure you always cite the source of the content and whether the table has been adapted from another source.
[Disease name] is primarily diagnosed based on clinical presentation. There are no established criteria for the diagnosis of [disease name].
OR
There is no single diagnostic study of choice for [disease name], though [disease name] may be diagnosed based on [name of criteria] established by [...].
OR
The diagnosis of [disease name] is made when at least [number] of the following [number] diagnostic criteria are met: [criterion 1], [criterion 2], [criterion 3], and [criterion 4].
OR
The diagnosis of [disease name] is based on the [criteria name] criteria, which includes [criterion 1], [criterion 2], and [criterion 3].
OR
[Disease name] may be diagnosed at any time if one or more of the following criteria are met:
- Criteria 1
- Criteria 2
- Criteria 3
OR
IF there are clear, established diagnostic criteria
The diagnosis of [disease name] is made when at least [number] of the following [number] diagnostic criteria are met: [criterion 1], [criterion 2], [criterion 3], and [criterion 4].
OR
The diagnosis of [disease name] is based on the [criteria name] criteria, which include [criterion 1], [criterion 2], and [criterion 3].
OR
The diagnosis of [disease name] is based on the [definition name] definition, which includes [criterion 1], [criterion 2], and [criterion 3].
OR
IF there are no established diagnostic criteria
There are no established criteria for the diagnosis of [disease name].
References
- ↑ Parekh BS, Ou CY, Fonjungo PN, Kalou MB, Rottinghaus E, Puren A; et al. (2019). "Diagnosis of Human Immunodeficiency Virus Infection". Clin Microbiol Rev. 32 (1). doi:10.1128/CMR.00064-18. PMC 6302353. PMID 30487166.