Friday, April 19, 2024

What Is Hiv 2 Antibody

What Is The Window Period And What Is The Window Period For The Insti Rapid Hiv Test

INSTI HIV-1 / HIV-2 Antibody Test: Controls Test Procedure (Canada)

After exposure to HIV, it can take from 3 to 12 weeks for an infected persons body to make enough antibodies for a screening test to detect them. This is called the window period. IgM antibodies are the first antibodies to be detected by INSTI and are typically present in the bloodstream approximately 3 weeks after infection. An individual may test positive with the INSTI Test in as little as 21-22 days after infection, however depending on the person it can take as long as 3 months for them to produce sufficient antibodies to generate a positive result. Approximately 97% of people will develop detectable antibodies during this window period.A negative result may not be accurate until 3 months after a possible exposure. If someone has been exposed to HIV and obtains a negative test result during the window period, they should re-test 3 months after possible exposure to HIV.

Current Functional Cure Strategies And The Possibility Of Such Studies In Hiv

As the research field of HIV cure has matured over recent years, it has been necessary to define different concepts of the term cure . Within HIV-1 cure research, the aspect of functional cure has emerged, or lately relapse-free remission to define sustained suppression of virus without the need for ART. This means that a functional cure does not have to result in complete absence of HIV in the body. Several different cure strategies have been suggested, e.g. stimulation of the latently infected cells to reduce the reservoir size gene therapy to reduce the number of target cells and immunotherapy to ameliorate the HIV-specific immune response . An example of naturally occurring functional cure are so-called elite controllers, which has been described in a small minority of HIV-1 patients . Interestingly, this phenomenon seems to be much more frequent among HIV-2 infected individuals, and it is largely unknown why this is the case . Therefore, there are important lessons to be learned from HIV-2 pathogenesis, and HIV-2 may represent a model to study relapse-free remission and open up new avenues towards how to induce relapse-free remission in HIV-1 infection .

Table 1 Strengths and weaknesses of the Bissau HIV and the Guinea-Bissau police cohorts and associated research teams

Why Do I Need An Hiv Test

The Centers for Disease Control and Prevention recommends that everyone between the ages of 13 and 64 get tested for HIV at least once as part of routine health care. You may also need an HIV test if you are at higher risk for infection. HIV is mainly spread through sexual contact and blood, so you may be at a higher risk for HIV if you:

  • Are a man that has had sex with another man
  • Have had sex with an HIV-infected partner
  • Have had multiple sex partners
  • Have injected drugs, such as heroin, or shared drug needles with someone else

HIV can spread from mother to child during birth and through breast milk, so if you are pregnant your doctor may order an HIV test. There are medicines you can take during pregnancy and delivery to greatly reduce your risk of spreading the disease to your baby.

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Cross Type Neutralizing Antibodies Detected In A Unique Hiv

  • 1Division of HIV/AIDS, Department of Clinical Research, National Institute for Research in Tuberculosis , Chennai, India
  • 2Department of Infectious Diseases Laboratory, Y.R. Gaitonde Centre for AIDS Research and Education , Chennai, India

Background: Infection with HIV-2, a retrovirus that is closely related to HIV-1, is characterized by slower disease progression and transmission, longer latency period and low or undetectable viremia. Host immunity, including production of potent neutralizing antibodies, may be one of the possible contributors to the distinction between the two infections. In an attempt to understand whether HIV-2 infection results in production of neutralizing antibodies and to characterize the nature of the neutralization response we screened plasma of 37 HIV-2 infected individuals for the presence of broadly neutralizing antibodies.

Materials and Methods: Thirty seven asymptomatic, ART-naïve, HIV-2 infected individuals were recruited for the study. Plasma obtained from these individuals were screened for the presence of broadly cross reactive neutralizing antibodies using the standard neutralization screening protocol with a panel of HIV-1 and HIV-2 pseudoviruses. Plasma exhibiting broad neutralization activity were assessed for their potency employing a titration assay. Further, an attempt was made to characterize the neutralization specificity of the plasma exhibiting broad and potent neutralization activity.

What Is Hiv 2 Antibody


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. Regarding this, what does HIV antibody positive mean?

A positive HIV antibody test means that the body has been exposed to HIV . A person with a positive HIV test will need to have further testing done to confirm this diagnosis.

Also, what is HIV 2 infection? One of the two types of HIV, the virus that causes AIDS. AIDS is the most advanced stage of HIV infection. HIV2 infection is endemic to West Africa. HIV2 infection generally takes longer to progress to symptomatic HIV/AIDS than HIV-1.

Subsequently, one may also ask, what is HIV 2 test?

HIV2 is usually diagnosed by detecting HIV2 specific antibodies with specialized tests known as HIV-1/HIV2 differentiation immunoassays. HIV2 infection can also be diagnosed by detecting HIV2 nucleic acid .

What are the symptoms of HIV 2?

Symptoms can include:

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What Do The Test Results Mean

It may take up to 2 weeks to get the test results. Results are only given to you. Some states have to report results to the health department. Talk to your caregiver if you have concerns about how the test is reported in your area.

  • A positive test means that you may have the HIV virus. It does not necessarily mean you have AIDS. Once a person is infected with this virus, you will remain infected for life. Some people infected with HIV seem healthy and show no symptoms for several years. Others may get sick with AIDS or have symptoms of an HIV infection. You cannot get rid of the virus and it will not go away. There is no cure for HIV infection. There are medicines to help slow down the infection. There are also medicines to help fight other infections that HIV positive people may get.
  • A negative test means that you probably do not have the HIV virus. However, you may need to follow up with repeat tests. These tests are especially important if you have done things during the last year that put you at high-risk to get HIV. Your body takes from 6 to 8 weeks to develop the antibodies to HIV.

Viruses And Env Targets Of Neutralization Infectious Stocks Of Primary Hiv

Infectious stocks of primary HIV-2 strains were produced in 293T cells by transfection with molecular clones of HIV-27312A, HIV-2ST, and HIV-2UC1 and by infection and productive replication in CD4+ T cells. To generate 293T-grown virus stocks, HIV-2 proviral clones pJK7312A and pSTsxb1 were transfected into 293T cells using Fugene 6 as described previously . The HIV-2UC1env expression construct pSM-UC1 was cotransfected into 293T cells with HIV-2 backbone construct pJK7312AEnv. To generate PBMC-grown virus stocks, human CD4+ lymphocytes were isolated, activated, and cultured as described above. Within 3 to 4 days after SEB activation, 10 × 106 cells were incubated with 293T-grown HIV-27312A and HIV-2ST at a high MOI in a small volume for 2 h at 37°C, washed three times to remove inocula, and then cultured in complete medium at a concentration of 1 × 106 cells/ml. Starting from 3 dpi, medium was changed by low-speed centrifugation every 2 days until 12 dpi. The supernatants were collected, centrifuged at 3,000 rpm for 20 min, aliquoted, and stored at 80°C for future titration and infection. For CD4+ T-cell-based multicycle infectivity assay, the supernatants were concentrated up to 100-fold by sucrose gradient ultracentrifugation.

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Discusses Physiology Pathophysiology And General Clinical Aspects As They Relate To A Laboratory Test

Human immunodeficiency virus type 2 is a lentivirus, a retrovirus in the same genus as HIV-1. It was first isolated in 1986 in West Africa, where it is currently endemic. As of June 2010, CDC has reported a total of 166 cases that met the CDC case definition of HIV-2 infection in the United States. Most of these cases were found in the northeastern United States, and the majority had a West African origin or connection.

Compared to HIV-1 infection, HIV-2 infection is associated with slower rate of progression, low viral load , slower rates of decline in CD4 cell count, and lower rates of transmission . Up to 95% of HIV-2-infected individuals are long-term nonprogressors, and individuals with undetectable HIV-2 viral load have similar survival rates as that of the uninfected population. However, HIV-2 does cause immunosuppression as well as AIDS with the same signs, symptoms, and opportunistic infections seen in HIV-1. Due to the rarity of HIV-2, there are scant data from controlled trials to inform management decisions.

Although there are several FDA-approved screening assays to detect combined HIV-1 and HIV-2 antibodies or HIV-2 antibodies alone, currently there is only one FDA-approved supplemental HIV-2 serologic assay for clinical use in the United States.

Provides Information To Assist In Interpretation Of The Test Results

INSTI HIV-1 / HIV-2 Antibody Test: Controls Test Procedure

Negative results for HIV-2 antibodies usually indicate the absence of HIV-2 infection. However, in patients with reactive initial combined HIV-1/-2 antigen and antibody test results, such negative results do not rule-out acute or early HIV-2 infection. If acute or early HIV-2 infection is suspected, detection of HIV-2 DNA/RNA is recommended, based on the patient’s clinical and epidemiologic exposure history.

Positive HIV-2 antibody results indicate the presence of HIV-2 infection. Additional testing with a new whole blood specimen for HIV-2 DNA/RNA is recommended to verify and confirm the diagnosis of HIV-2 infection prior to initiating antiretroviral treatment.

Indeterminate HIV-2 antibody results may be due to acute HIV-1 infection or very early HIV-2 infection . If acute HIV-1 infection or early HIV-2 infection is suspected, detection of HIV-1 RNA and/or HIV-2 DNA/RNA is recommended, depending on the epidemiologic exposure history.

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When Can You Get A 4th Generation Hiv Test

Currently there no HIV tests that can detect the presence of HIV immediately.

Once someone is exposed to the virus, the body starts producing antibodies, this is called seroconversion. HIV tests cant reliably detect the virus during the window period the time from when a person gets the infection to when tests can detect the virus.

This time can vary from person to person. Testing too early will give false negative results, meaning you have the virus, but you test negative.

In some people, the virus can be detected within 2 weeks of exposure, depending on the type of test. The fourth generation test can detect p24 within 1 month of exposure. If you test before the average window period of 18 days, you may get a false negative test.

If you think youve been exposed to HIV, its important to contact your healthcare provider or visit a health clinic to get tested and begin prevention treatment if needed. If you receive a negative test, be sure to do a follow-up test.

Your healthcare provider may start you on the pre-exposure prophylaxis medication protocol as a prevention measure. PrEP medications can reduce the risk for infection, if started within 72 hours of high risk exposure.

The fourth generation test is reliable and highly accurate.

The reliability of tests depends on:

  • when you get tested
  • which test is used
  • the individual

Both Intratype And Intertype Neutralizing Activity Identified In One Hiv

To assess the neutralizing activity, plasma samples of all 37 individuals were tested against a 293 T cell derived HIV-2 enveloped pseudovirus HIV-2 7312A and a PBMC derived primary virus HIV-2 NIRT010. All plasma samples showed potent heterologous neutralization against both the viruses. The neutralization titers of all the plasma samples are represented in Table 2. Geometric mean titer was calculated for each plasma against the HIV-2 viruses . GMT of the plasma samples ranged from 80 to 23053.

Table 2. Neutralization titers of 37 HIV-2 plasma aganist HIV-2 viruses ID50.

Table 3. Neutralization breadth of BCN plasma against HIV-1 pseudoviruses.

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How Is It Used

HIV antibody and HIV antigen testing is used to screen for and diagnose HIV infections. Early detection and treatment of HIV infection and immune system monitoring can greatly improve long-term health and survival. Also, if a person knows his or her HIV status, it may help change behaviors that can put him or her and others at risk.


Different types of tests may be used for HIV screening:

  • Combination HIV antibody and HIV antigen testthis is the recommended screening test for HIV. It is available only as a blood test. It detects the HIV antigen called p24 plus antibodies to HIV-1 and HIV-2. The level of p24 antigen and the amount of virus increase significantly soon after initial infection. Testing for p24 allows for detection of early infections, before HIV antibody is produced. A few weeks after exposure, antibodies to HIV are produced in response to the infection and remain detectable in the blood thereafter, making the antibody test useful for detecting infections weeks after exposure. By detecting both antibody and antigen, the combination test increases the likelihood that an infection is detected soon after exposure. These tests can detect HIV infections in most people by 2-6 weeks after exposure.
  • p24 antigen testingthis is used alone without the antibody test only in rare cases when there is a question about interference with an HIV antibody test.
  • There are a few different ways a person can get access to HIV screening:


    Evidence For N Linked Glycan Dependent Neutralizing Activity In The Bcn Plasma

    Core Concepts

    Figure 4. Identification of Glycan dependent antibodies. Neutralization curves of BCN plasma sample aganist HIV-1 subtype C tier-2 pseudoviruses DU156 WT and mutant with substitutions at glycan position 160 and 332. Neuralization titration assay was performed with BCN plasma sample in duplicates at dilutions ranging from 1:10 to 1:100,000 on two independent occasions.

    Table 5. Identification of glycan dependent antibodies in BCN sample.

    Figure 5. Neutralization sensitivity assay to detect Glycan-dependent antibodies. Dose response curve of BCN plasma with JR-FL wild type and E168K mutant for recognzing glycan depend antibodies. Neutralization activity against glycan positions at N156 and N160 in the JR-FL E168K mutated strain for the confirmation of glycan dependent bNAbs.

    Table 6a. Neutralization activity of the BCN plasma sample against HIV-1 JR-FL and E168K mutant pseudoviruses.

    Table 6b. Neutralization activity against HIV-1 JR-FL E168K and double mutated pseudoviruses JR-FL E168K N156K JR-FL E168K N160K and JR-FL E168K N332A.

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    What Are Hiv Tests Used For

    An HIV test kit is used to determine if you have contracted HIV. HIV is the virus that causes AIDS . Most people with HIV do not have AIDS. Cells and are at risk for life-threatening diseases, including dangerous infections, severe pneumonia, and certain cancers. If HIV is detected early, you can get medications that will help you protect your immune system. HIV medication can prevent you from getting AIDS.

    Study Shows That Some Tests Fall Short In Early Infection

    As the United States aims to increase early diagnosis and treatment of people with HIV, a greater focus has been placed on determining the accuracy of HIV tests in real-world settingsnot only to minimize the number of false positive or negative test results but to better identify people during the early stages of infection when the risk of transmission is especially high.

    In order to do this, researchers from the University of California, San Francisco conducted a review of over 21,000 HIV tests performed between the years 2003 and 2008 in some of the citys high prevalence populations.

    Of four types of tests used during this periodfrom first generation antibody tests to rapid oral tests761 people were diagnosed with HIV , while 58 were identified during acute infection.

    The study also aimed to compare the accuracy of newer testing assaysincluding 4th generation antigen/antibody testsby retesting the blood from the 58 people previously diagnosed with acute HIV infection.

    The accuracy was measured both in terms of sensitivity and specificity .

    Test Type

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    What Is Hiv 1 And 2 Antibody

    This test is done to confirm the HIV-1 and HIV-2 antibodies present in the blood. It also helps in differentiating HIV-1 and HIV-2 antibodies in specimens of serum which show reactive results with third and fourth generation HIV serologic assays. This test is not a screening test to detect HIV infection.

    What Is The Hiv Antibody Test Window Period

    INSTI HIV-1 / HIV-2 Antibody Test: Serum and Plasma Test Procedure

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    Hiv 1 And 2 Antibodies Test

    The HIV 1 and 2 Antibodies test is used to detect the presence of HIV infection. The test can be performed post 3 to 12 weeks of exposure. In the test, a blood sample or an oral sample is collected. In case of oral sample testing, the result can be obtained within 20 minutes. This can be done at home as well. The test is suggested in cases where the individual has consumed drugs through un-sanitized syringe, or has had unprotected sex with unknown partner. Early testing in above cases can help control sexual activity and help long term survival.

    The blood sample is to be taken from a visible vein near the elbow joint. So it is recommended to wear half sleeve shirt. Full sleeve shirt if could be rolled over would be fine too. Sample can also be obtained from the finger if the attendant feels so would be helpful In case oral sample is to be obtained, then avoid eating just before the test or rinsing the mouth is recommended.

    The HIV 1 and 2 Antibody is used to test presence of HIV infection. The test is conducted after 3 to 12 weeks after suspected exposure to the HIV causing scenarios mentioned above. Early detection and diagnosis could help in controlling sexual activity. This also helps in monitoring the immune system functioning and can thereby help in long term survival is detected early. HIV 1 type infection is mainly detected in patients across the USA. However, HIV2 is mainly found in African countries.

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