šta ko kaže je malo važno, tačno je ono što u udžbenicima piše, a virusloška dijagnostika podrazumeva serološku i molekularnu, koja prema vodiču dobre prakse izgleda ovako:
HIV antibody testing with or without HIV P24 antigen tests
Nucleic acid amplification assays to determine HIV RNA level (viral load)
HIV infection is suspected in patients with persistent, unexplained, generalized adenopathy or any of the AIDS-defining illnesses (see sidebar AIDS-Defining Illnesses). It may also be suspected in high-risk patients with symptoms that could represent acute primary HIV infection.
Diagnostic tests
Detection of antibodies to HIV is sensitive and specific except during the first few weeks after infection (termed the "window period" of acute HIV infection). However, the HIV p24 antigen (a core protein of the virus) is already present in the blood during most of this time and can be detected by assays.
Currently, a fourth-generation antigen/antibody combination immunoassay is recommended; it detects antibodies to both HIV-1 and HIV-2 as well as the p24 HIV antigen. The laboratory version is probably preferred over the point-of-care test for diagnosing early infection, but both can be done quickly (within 30 minutes). If the test result is positive, an assay to differentiate HIV-1 and HIV-2 and an HIV RNA assay are done.
Earlier-generation enzyme-linked immunosorbent assay (ELISA) antibody assays are highly sensitive, but because they do not test for antigen, they are not positive as early as the fourth-generation combination test. Also, results are rarely false-positive. Positive ELISA results are therefore confirmed with a more specific test such as Western blot. However, these tests have drawbacks:
ELISA requires complex equipment.
Western blot requires well-trained technicians, is expensive, and takes several days or weeks for results to be available.
The full testing sequence takes at least a day.
Most settings use an HIV-1/HIV-2 differentiation assay as their preferred confirmatory test, replacing the cumbersome Western blot. Additionally, HIV-1 Western blot assays do not reliably detect subtype O virus prevalent in some African regions; if HIV-2 is being considered, a special HIV-2 Western blot needs to be requested (1). Point-of-care tests using blood or saliva (eg, particle agglutination, immunoconcentration, immunochromatography) can be done quickly (in 15 minutes) and simply, allowing testing in a variety of settings and immediate reporting to patients. Positive results of these rapid tests should be confirmed by standard blood tests (eg, ELISA with or without Western blot) in high-resource countries and repetition with one or more other rapid tests in high HIV burden countries. Negative tests need not be confirmed.
If HIV infection is suspected despite negative antibody test results (eg, during the first few weeks after infection), the plasma HIV RNA level should be measured. The nucleic acid amplification assays used are highly sensitive and specific. HIV RNA assays require advanced technology, such as reverse transcription–polymerase chain reaction (RT-PCR), which is sensitive to extremely low HIV RNA levels. Measuring p24 HIV antigen by ELISA is less sensitive and less specific than directly detecting HIV RNA in blood.
Pitanje broj: #235998
Postovanje doktore,ne znam koja je tacna vise ova informacija,neki doktori kažu 6nedeja za HIV ,neki 3* meseca ,neki 6 meseca...da covek mne poveruje,bas citam načelnik klinike za aids dr Jovan ranin i dalje navodi da ja maksimalni period za HIV 6 meseci,dodatno Jos ako je elisa negativna a postoji cvrsti razlog za infekciju radi se PCR!To Pise i to je on izjavio!Covek ne zna kome da veruje i koliko je sve to tačno ,ako jedan Kaze ovako jedan onako ljudi nece verovati!https://www.google.com/url?sa=t&source=web&rct=j&opi=89978449&url=https://eklinika.telegraf.rs/zdravlje/122749-hiv-moze-godinama-da-tinja-bez-simptoma-koliko-osoba-ima-hiv-a-da-to-i-ne-zna&ved=2ahUKEwiyta7yjbOKAxVs_7sIHe2EAfYQFnoECBUQAQ&usg=AOvVaw3Pit8zT_bwp0WEIyLDwamk(evo linka)
Odgovoreno: 19. 12. 2024.šta ko kaže je malo važno, tačno je ono što u udžbenicima piše, a virusloška dijagnostika podrazumeva serološku i molekularnu, koja prema vodiču dobre prakse izgleda ovako:
HIV antibody testing with or without HIV P24 antigen tests
Nucleic acid amplification assays to determine HIV RNA level (viral load)
HIV infection is suspected in patients with persistent, unexplained, generalized adenopathy or any of the AIDS-defining illnesses (see sidebar AIDS-Defining Illnesses). It may also be suspected in high-risk patients with symptoms that could represent acute primary HIV infection.
Diagnostic tests
Detection of antibodies to HIV is sensitive and specific except during the first few weeks after infection (termed the "window period" of acute HIV infection). However, the HIV p24 antigen (a core protein of the virus) is already present in the blood during most of this time and can be detected by assays.
Currently, a fourth-generation antigen/antibody combination immunoassay is recommended; it detects antibodies to both HIV-1 and HIV-2 as well as the p24 HIV antigen. The laboratory version is probably preferred over the point-of-care test for diagnosing early infection, but both can be done quickly (within 30 minutes). If the test result is positive, an assay to differentiate HIV-1 and HIV-2 and an HIV RNA assay are done.
Earlier-generation enzyme-linked immunosorbent assay (ELISA) antibody assays are highly sensitive, but because they do not test for antigen, they are not positive as early as the fourth-generation combination test. Also, results are rarely false-positive. Positive ELISA results are therefore confirmed with a more specific test such as Western blot. However, these tests have drawbacks:
ELISA requires complex equipment.
Western blot requires well-trained technicians, is expensive, and takes several days or weeks for results to be available.
The full testing sequence takes at least a day.
Most settings use an HIV-1/HIV-2 differentiation assay as their preferred confirmatory test, replacing the cumbersome Western blot. Additionally, HIV-1 Western blot assays do not reliably detect subtype O virus prevalent in some African regions; if HIV-2 is being considered, a special HIV-2 Western blot needs to be requested (1). Point-of-care tests using blood or saliva (eg, particle agglutination, immunoconcentration, immunochromatography) can be done quickly (in 15 minutes) and simply, allowing testing in a variety of settings and immediate reporting to patients. Positive results of these rapid tests should be confirmed by standard blood tests (eg, ELISA with or without Western blot) in high-resource countries and repetition with one or more other rapid tests in high HIV burden countries. Negative tests need not be confirmed.
If HIV infection is suspected despite negative antibody test results (eg, during the first few weeks after infection), the plasma HIV RNA level should be measured. The nucleic acid amplification assays used are highly sensitive and specific. HIV RNA assays require advanced technology, such as reverse transcription–polymerase chain reaction (RT-PCR), which is sensitive to extremely low HIV RNA levels. Measuring p24 HIV antigen by ELISA is less sensitive and less specific than directly detecting HIV RNA in blood.
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