Ultrasensitive p24 Antigen Assay for Diagnosis of Perinatal Human Immunodeficiency Virus Type 1 Infection

Fiscus, Susan A.; Wiener, Jeffrey; Abrams, Elaine J.; Bulterys, Marc; Cachafeiro, Ada; Respess, Richard

doi:10.1128/jcm.00813-07

Cited by 32 publications

(20 citation statements)

References 32 publications

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“…Many studies support the use of the Perkin Ultra p24 immunoassay for early diagnosis in infants aged 10 days to 12 months. 30,36,37 p24 immunoassay Policy & practice Low-cost tools for HIV diagnosis and monitoring Grace Wu & Muhammad H Zaman of dried blood spot samples had 94.4% sensitivity and 100% specificity in another study. These findings are promising because dried blood spot analysis is common for infant diagnosis in rural areas.…”

Section: Early Infant Diagnosismentioning

confidence: 99%

“…29 Several reports support the use of the EXAVir Load Version 3 nucleic acid test for HIV load monitoring in the developing world. 14,[29][30][31] In this test, a gel-separation step isolates virions from plasma components. The virions are then lysed and the lysates undergo a modified ELISA to measure the activity of reverse transcriptase.…”

Section: Hiv Load Monitoringmentioning

confidence: 99%

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Low-cost tools for diagnosing and monitoring HIV infection in low-resource settings

Zaman

2012

Bull. World Health Organ.

148

103

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Section: Early Infant Diagnosismentioning

confidence: 99%

Section: Hiv Load Monitoringmentioning

confidence: 99%

Low-cost tools for diagnosing and monitoring HIV infection in low-resource settings

Zaman

2012

Bull. World Health Organ.

148

103

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“…The persistence of maternal antibodies against HIV in exposed infants up to 18 months of age prevents the use of the enzyme-linked immunosorbent assay for the early diagnosis of HIV infection. Thus, approaches to the early diagnosis of infection in infants have included ultrasensitive heat-denatured p24 antigen quantitation (4,16,23) and nucleic acid amplification techniques that target HIV DNA (15), RNA (14), or total nucleic acid (3,10,18), most commonly with samples obtained at 6 weeks of age. It has also been established that the collection of blood as dried blood spots (DBSs) improves access to tests for the early diagnosis of HIV infection among infants in resource-limited settings (2,17).…”

Section: Most Human Immunodeficiency Virus (Hiv)-infected Infants Resmentioning

confidence: 99%

Ultra-High-Throughput, Automated Nucleic Acid Detection of Human Immunodeficiency Virus (HIV) for Infant Infection Diagnosis Using the Gen-Probe Aptima HIV-1 Screening Assay

Stevens

Noble

Berrie³

et al. 2009

J Clin Microbiol

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The early diagnosis of human immunodeficiency virus (HIV) infection in infants is critical to ensure the initiation of treatment before significant immunological compromise. Each year an estimated 300,000 HIVexposed infants in South Africa require access to tests for the diagnosis of HIV infection. Currently, testing is performed at several facilities by using PCR amplification of HIV DNA at 6 weeks of age by the use of dried blood spots (DBSs) and whole blood (WB). The Gen-Probe Aptima HIV type 1 (HIV-1) screening assay (the Aptima assay) is a qualitative nucleic acid test based on transcription-mediated amplification (TMA), a technology routinely used in blood banks in South Africa. The performance characteristics of Gen-Probe's TMA technology compared well to those of the Roche Amplicor HIV-1 DNA (version 1.5) assay. The sensitivity of the assay with WB and DBS samples was 100%, and the specificities were 99.4% and 99.5% for DBSs and WB, respectively. The detection of HIV by the Aptima assay at greater levels of dilution in samples negative by the comparator assay indicates an improvement in sensitivity by the use of the TMA technology. The ability to process 1,900 samples in a 24-h period on the Tigris instrument makes the Aptima assay an attractive option for high-volume, centralized laboratories.

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“…Others have suggested that p24 assays might be less specific in very young infants (24). However, we previously tested plasma samples with the Up24 assay and observed similar specificity in infants 0 to 7 days of age (1 of 109 [99%]) (11). The optimal time to use the Up24 antigen assay for infant diagnosis requires further investigation, especially as prevention of mother-to-child transmission programs in low-resource countries move to more-complex and longer postdelivery antiretroviral regimens.…”

mentioning

confidence: 99%

“…It has been used successfully with plasma for over 12 years for diagnosis of HIV infection in infants (9,11,13,18,19,26,29,32).…”

mentioning

confidence: 99%

Diagnosis of Human Immunodeficiency Virus Type 1 Infection in Infants by Use of Dried Blood Spots and an Ultrasensitive p24 Antigen Assay

et al. 2009

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We tested 617 dried blood spots (DBS) from human immunodeficiency virus-exposed infants from five countries using an ultrasensitive p24 antigen assay (Up24). The sensitivity was 94.4% (67/71) and the specificity was 100% (431/431) for infants with DBS specimens <20 months old; DBS older than 30 months demonstrated only 72.2% sensitivity (39/54) (P < 0.001) but displayed 100% specificity (61/61).Several factors reduce diagnosis of human immunodeficiency virus (HIV) in infancy in resource-limited settings. Simple, rapid antibody assays cannot be used because of the presence of maternal antibodies. As a consequence, viral nucleic acids or proteins must be detected. Nucleic acid assays are technologically complex and subject to contamination and require expensive equipment and highly trained technologists, limiting availability to selected centers of excellence in resource-limited countries (1,8,12,15,28,30).The ultrasensitive p24 antigen assay (Up24), an alternative that overcomes the limitations of antibody assays while using an enzyme-linked immunosorbent assay (ELISA)-based platform, reduces the need for expensive equipment and personnel. It has been used successfully with plasma for over 12 years for diagnosis of HIV infection in infants (9,11,13,18,19,26,29,32).Another factor limiting diagnosis of HIV infection in infants is the need for phlebotomy to collect specimens and cold chain maintenance while the specimen is transported to a central laboratory. These have been addressed by adaptation of nucleic acid (2-7, 10, 16, 20, 21, 27, 31), and now Up24 antigen assays, for use with dried blood spots (DBS) (14,22,23).Other investigators have adapted the Up24 assay for use with DBS. Table 1 compares these different extraction methods used for p24 antigen assays with DBS. Li et al. (17), following the manufacturer's instructions for plasma specimens, reported 0% specificity using DBS. Knuchel et al. (14) improved the sensitivity by modifying the elution buffer (25) and increased specificity to 100% by adding a quenching step using hydrogen peroxide after the first wash. Patton et al. (22,23) improved elution by using the previously described buffer (25) and 0.5% Triton X-100. The reported sensitivity and specificity were 98.3 to 98.8% and 100%, respectively. Our objectives were to develop and optimize a simpler method for HIV infant diagnosis using DBS and reagents found in commercially available Up24 test kits as much as possible and to assess the optimized assay performance.

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Ultrasensitive p24 Antigen Assay for Diagnosis of Perinatal Human Immunodeficiency Virus Type 1 Infection

Cited by 32 publications

References 32 publications

Low-cost tools for diagnosing and monitoring HIV infection in low-resource settings

Low-cost tools for diagnosing and monitoring HIV infection in low-resource settings

Ultra-High-Throughput, Automated Nucleic Acid Detection of Human Immunodeficiency Virus (HIV) for Infant Infection Diagnosis Using the Gen-Probe Aptima HIV-1 Screening Assay

Diagnosis of Human Immunodeficiency Virus Type 1 Infection in Infants by Use of Dried Blood Spots and an Ultrasensitive p24 Antigen Assay

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