ABSTRACT
Objective:Comparison of commercially available three HIV antibody detection kit for HIV infection,found as early HIV infection provides a reference method.Methods:By using two fourth generation HIV Kit ( Murex HIV Ag/Ab Kit:British Abbott company production numbers for A;Holland Organon company Vironostika HIV Uni-Form II Ag/Ab Kit:No.B;) a third generation HIV Kit ( British Abbott company produced Murex HIV-1.2.O Kit:No.C) and P24 antigen detection kit for 3 863 blood samples and BBI positive blood winding detection,sensitivity analysis,the specificity for the two fourth generation HIV kit for detecting,at the same time analysis of three kinds of antibody detection kit for detection of HIV infection window period of time whether the advance.Results:A kit,B were all positive blood samples from 54 patients with HIV infection,the sensitivity of A detection kit=100%,the specificity =99.61%, the rate of missed diagnosis=0, misdiagnosis rate=0.39%;the sensitivity of B detection kit=100%, the specificity =99.37%,the rate of missed diagnosis=0,misdiagnosis rate=0.63%;reagent A and B detection results are compared,the results did not show significant difference (P>0.05) ;A kit,B kit respectively compared with C reagent detection window period ahead of 5.5 and 3.7 d,but compared with P24 antigen kit detection window period was a lag of 4.25 to 6.05 d.Conclusion:In this study,the ability of two fourth generation HIV kit for detection of HIV infection in the strong sensitivity,reached 100%,but can be HIV infection window period in advance,to ensure the safe use of blood.
ABSTRACT
Se modificó el ELISA DAVIH-Ag P24 con la introducción de la disociación por calor de las muestras de plasma y el empleo de un sistema de amplificación biotina-tiramina/estreptavidina-peroxidasa, para incrementar su sensibilidad. Se determinó la repetibilidad interensayo en el DAVIH-Ag P24 amplificado. Se evaluaron 32 muestras de plasma de individuos infectados por el VIH-1 en 3 categorías clínicas (caso SIDA, asintomßticos y con infecciones oportunistas menores). En la determinación de la repetibilidad interensayo se obtuvo un coeficiente de variación entre 4 y 10,3 por ciento. Con el DAVIH-Ag P24 amplificado se incrementó el nivel de detección de P 24 hasta 0,5 pg/mL. El DAVIH-Ag P24 amplificado alcanzó 66 por ciento de sensibilidad, mientras que el DAVIH-Ag P24 obtuvo 31 por ciento. Este estudio preliminar permitió demostrar que la incorporación de las nuevas modificaciones al sistema DAVIH-Ag P24 amplificado logró aumentar los niveles de detección de P24 y ganar en sensibilidad.
ELISA DAVIH-Ag p24 was modified by introducing heat dissociation of plasma samples and a tyramine/streptavidine-peroxidase amplification system, with the objective of increasing sensitivity. Between-assay repeatability was determined in amplified DAVIH-Ag p24. Thirty two plasma samples from HIV-1-infected individuals classified in three clinical categories (AIDS case, asymptomatic and minor opportunistic infections) were evaluated. The variation coefficient ranged 4-10.3 percent in between-assay repeatability. With the amplified DAVIH-p24 Ag, the p24 antigen detection level increased to 0.5 pg/mL. Amplified DAVIH-p24 Ag reached 66 percent sensitivity whereas standard DAVIH-p24 Ag sensitivity rate was 31 percent. This preliminary study proved that the introduction of new modifications in amplified DAVIH-p24 Ag managed to increase the p24 antigen detection levels and to gain sensitivity.
Subject(s)
Humans , HIV , /analysis , /chemistryABSTRACT
Introducción: La inclusión en las pruebas de detección del VIH de la capacidad de determinar el antígeno p24 ha potenciado su capacidad diagnóstica para infecciones recientes. Objetivos: Evaluar el antígeno p24 como predictor de infección reciente por VIH en pacientes con prueba confirmatoria negativa. Método: Estudio descriptivo de seroconversión en 245 muestras de personas desde los 14 años de edad con resultado confirmatorio negativo para el VIH, en muestras de las serotecas de los laboratorios de Salud Pública Distrital y el Centralizado de VIH en la ciudad de Bogotá, Colombia. Se encontraron en 12 de ellas y se estudió la seroconversión en 6. Resultados: Se confirmó seroconversión en el 60% de pacientes positivos para prueba presuntiva de p24 y en el 75% de los positivos para confirmatoria del mismo antígeno. Conclusiones: Estos resultados sugieren la necesidad de realizar pruebas diagnósticas adicionales a todos los casos con resultado reactivo en prueba presuntiva y negativo para confirmatoria, en los que la reactividad de la primera pueda estar determinada por la presencia del antígeno p24 en a muestra, a fin de establecer una posible infección reciente por este virus.
Background: The inclusion of the capacity to generate p24 antigen in presumptive tests to detect the Human Immunodeficiency Virus (HIV) have enhanced its diagnosing potential in recent infection cases. The absence of this condition in confirmatory tests creates a risk of false negatives. Aims: To assess p24 antigen as a predictor of recent HIV infection in patients with negative confirmation test. Methods and design: Descriptive study of seroconversion of patients with confirmed negative test for HIV. Scenario: A study based on samples taken from the erum banks of the District Public Health Lab and Centralized HIV Lab in Bogotá, D.C., Colombia. Participants: p24 antigen was sought in 245 samples of people aged 14 or older, either reactive for presumptive tests or negative for confirmatory tests. The antigen was found in 12 of them and seroconversion took place in 6 of them. Interventions: 253 blood samples, either reactive for presumptive tests or negative for confirmatory tests were obtained out of 393,247 samples taken between January 2006 and November 2007. Finally, seroconversion was studied in patients with reactive test for p24 antigen. Outcome measurement: Seroconversion took place in patients with reactive tests for p24 antigen test for presumptive test and negative confirmatory test. Results: Seroconversion was confirmed in 60% of the patients tested positive for presumptive p24 antigen and in 75% of the patients tested positive for confirmatory test of the same antigen. Conclusions: These results suggest the need to carry out additional diagnostic tests to all cases with reactive results in presumptive testing and negative confirmatory testing in which the reactivity of the presumptive testing can be determined by the presence of p24 antigen in the sample, in order to establish a possible recent infection by this virus.
Subject(s)
Humans , Male , Female , Probability , HIV Seropositivity , Viruses , Public Health , Diagnosis , Diagnostic Tests, Routine , Seroconversion , Indicators and Reagents , InfectionsABSTRACT
Objective : To evaluate the prediction of HIV-1 RNA viral load (Ampiclor) in log_copies per ml by each level of modified boosted-p24 antigen in log_ fg per ml. , Methods : 283 plasma samples were collected and blindly determined the HIV-1 RNA Amplicor Monitor, Roche as standard test with modified boosted p24 antigen assay. Likelihood ratio positive analyses of multiple levels of p24 were calculated as well as the post-test probability in predicting the amount of virus (log_copies/ ml). Results: Subject were between 18 to 73 years old with the range of virus 1.75 to 5.92 log-copies per ml. By the calculation of likelihood ratio positive and positive predictive value, it was demonstrated that modified boosted p24 antigen (Ag in log-fg per ml) might predict the viral load (VL in log-copies per ml) as follow. Ag 2.0-3.0 log-fg per ml corresponding to 2.0 or lower log-copies per ml VL Ag 3.0-3.5 log-fg per ml corresponding to 2.5 or lower log-copies per ml VL Ag 3.5-4.0 log-fg per ml corresponding to 3.5 or lower log-copies per ml VL Ag 4.0-over log-fg per ml corresponding to 4.5 or lower log-copies per ml VL Conclusions: In countries with limited financial resources, the modified p24 antigen may be clinically applied in antiretroviral management programmes, instead of the HIV-1 RNA Amplicor Monitor, Roche.
ABSTRACT
Current diagnosis of human immunodeficiency virus (HIV) infection relies on the detection of anti-HIV antibodies by enzyme-linked immunosorbent assay (ELISA). Recently, kits detecting both p24 antigenemia and anti-HIV/anti-HIV2 antibodies have been developed. Thus, it is necessary to compare those kits developed as such. The aim of this study was to evaluate the diagnostic efficiency of a simultaneous detection test of p24 antigen and anti-HIV1/2 antibodies in a low prevalence area. Eight hundred and four randomly selected sera proven negative for HIV infection and 110 sera from 54 patients diagnosed as HIV infected, obtained between 1999 and 2000, were used for this study. One commercial lot of panels composed of consecutive sera obtained from known HIV-infected patient was included. Anti-HIV1/2 antibodies were detected by two different commercial ELISA kits, one from Korean and the other from German manufacturer. P24 antigen test was performed by ELISA. The simultaneous HIV antigen and antibody detection test was carried out. In the meantime, HIV RNA PCR and anti-HIV and anti-HIV2 western blot assays were also performed to confirm the test results in cases the test results didn't agree. The simultaneous detection kit showed 100% sensitivity and 99.6% specificity. Furthermore, the test displayed the possibility of earlier diagnosis than conventional anti-HIV1/2 ELISA with the results obtained from a group of consecutive panel sera infected with HIV. From these results, we concluded that the simultaneous HIV antigen and antibody detection test can be applied as a substitute clinical screening test in the place of conventional anti-HIV1/2 ELISA, and there is the probable benefit of early diagnosis.
Subject(s)
Humans , Enzyme-Linked Immunosorbent Assay/standards , Enzyme-Linked Immunosorbent Assay/instrumentation , HIV Antibodies/analysis , HIV Antigens/analysis , Korea , Reagent Kits, Diagnostic/standardsABSTRACT
BACKGROUND: Human immunodeficiency virus(HIV) is the causative agent of acquired immune deficiency syndrome(AIDS). Current diagnosis of HIV infection relies on the detection of anti-HIV antibodies by ELISA. Recently, simultaneous detection kit of p24 antigenemia and anti-HIV1/anti-HIV2 antibodies were developed. The aim of this study was to evaluate the diagnostic kit of simultaneous detection with p24 antigen and anti-HIV1/2 in diagnostic aspect. METHODS: Eight hundred and four sera which were obtained between July 1999 and August 1999 and 110 sera from 54 patients diagnosed as HIV infection were included. One lot of panels composed of consecutive sera obtained from known HIV-infected patients was included. The detection of anti-HIV1/2 antibodies was done by Genedia HIV1/2 ELISA 3.0 kit(Greencross, Seoul, Korea) and Enzygnost anti-HIV1/2 Plus(Behringwerke, Marburg, Germany). The simultaneous detection of p24 antigenemia and anti-HIV1/2 antibodies was done with VIDAS DUO kit(bioMerieux, Lyon, France). The Vironostika HIV-1 antigen kit was used for detection of p24 antigen. The HIV RNA PCR and anti-HIV western blot assay were also performed to confirm the test results in discrepant cases. RESULTS: The simultaneous detection kit showed 100% sensitivity and 99.6% specificity. The possibility of earlier diagnosis than conventional anti-HIV1/2 EIA was also suggested by the results obtained with a group of consecutive panel sera infected with HIV. CONCLUSION: The simultaneous p24 antigen and anti-HIV1/2 detectin kit can be applied as a clinical screening test as a substitution of conventional anti-HIV1/2 EIA, and there is a probable gain especially in early diagnosis.
Subject(s)
Humans , Antibodies , Blotting, Western , Diagnosis , Early Diagnosis , Enzyme-Linked Immunosorbent Assay , HIV , HIV Infections , HIV-1 , Mass Screening , Polymerase Chain Reaction , RNA , Sensitivity and Specificity , SeoulABSTRACT
BACKGROUND: Recently some countries such as U.S.A. and Canada where human immunodeficiency virus(HIV) infection is rather prevalent, included HIV-1 p24 antigen test as a routine donor blood screening. This study was performed to evaluate the advantage of additional p24 antigen testing for the prevention of transfusion-associated AIDS infection in Korea. METHODS: Blood collected from 1726 volunteer blood donors, 16 HIV-positive patients, 39 sera from 4 commercial seroconversion panels, 15 sera included in low titer performance panel were tested with HIV-1 p24 Antigen ELISA Test System(Ortho Diagnostic Systems, U.S.A.). Anti-HIV antibody was also measured in parallel employing commercial kits produced by two world-famous companies. For some sera, western blot testing was additionally done. RESULTS: False-positive rate of p24 antigen testing was 0.06%. In 2 examples from 4 seroconversion panels, the p24 antigen test detected HIV infection 1-25 days and 11-47 days earlier than anti-HIV tests. CONCLUSION: Additional p24 antigen testing was found to have a potential to reduce transfusion-associated HIV infections. Including the p24 antigen testing as a routine donor screening should be considered if the number of transfusion-associated HIV infections continues to grow in Korea.
Subject(s)
Humans , Blood Donors , Blotting, Western , Canada , Donor Selection , Enzyme-Linked Immunosorbent Assay , HIV Infections , HIV-1 , Korea , Mass Screening , Tissue Donors , VolunteersABSTRACT
BACKGROUND: HIV-1 p24 antigen assay is useful for the detection of circulating viruses, and infection prior to seroconversion. However, circulating HIV-1 p24 antigen may be complexed with HIV antibody and prevent it from being detected by antigen capture assay. To detect HIV-1 p24 antigen in the specimen, it is necessary to dissociate immune complexes and confirm the presence of HIV-1 p24 antigen after the neutralization with the specific antibody. METHODS: We tested 32 sera from HIV-1 infected persons who were diagnosed from 1987 tO1996 in Korea for HIV-1 p24 antigen by enzyme linked immunosorbent assay (ELISA.) with or without the dissociation of immune complexes. And we confirmed the antigen assay results by the neutralization with HIV-1 specific antibody as a confirmatory test. We also calculated the concentration of HIV-1 p24 antigen in each specimen. RESULTS: Eleven of 32 sera tested were initially positive for HIV-1 p24 antigen. After the dissociation of immune complexes for 29 sera except two of which signal/cutoff ratios were higher than 7.0 and except one which was not enough for the assay,13 were shown to be positive for HIV-1 p24 antigen and their signal/cutoff ratios were increased by 10 times. Five of antigen negative cases were turned to be positive after the immune complex dissociation. After neutralization with HIV-1specific p24 antibody for sera of 13 which were positive for HIV-1 p24 antigen with or without the immune complex dissociation, all were shown to be neutralized. We have observed more than 90% neutralization reduction for 12 sera and more than 50% less than 90% for one. The average concentration of HIV-1 p24 antigen was8.76pg/ml by antigen assay and was increased to 76.81~g/m~ after immune complex dissociation. CONCLUSION: We concluded that the sensitivity and the specificity of HIV-1 p24 antigen assay could be increased by dissociation of the immune complexes and neutralization with the specific antibody.
Subject(s)
Humans , Antigen-Antibody Complex , Enzyme-Linked Immunosorbent Assay , HIV , HIV-1 , Korea , Sensitivity and SpecificityABSTRACT
Objective To describe a highly sensitive immuno-polymerase chain reaction (immuno-PCR) assay for the detection of human recombinant HIV-p24 antigen. Methods We used gold-magnetic particles as the carriers,mouse anti-p24 monoclonal antibody as the capture antibody and biotinylated goat anti-p24 polyclonal antibody as the detection antibody. The reporter DNA was initially generated by PCR amplification using a biotinylated primer,and was bound with streptavidin to biotinylated polyclonal antibody. Human recombinant p24 antigen sandwiched by antibodies was detected by amplifying the reporter DNA using PCR. The optimal concentration of sreptavidin and DNA label were determined using square titration. The electrophoresis gels were imaged and analyzed by Quantity One software. Results The optimal concentration of sreptavidin and DNA label were determined to be 0.1 mg/ L and 10 ng/ L,respectively. The detection limit of the immuno-PCR assay was 0.1 ng/L,higher than that of the conventional ELISA. Conclusion A highly sensitive immuno-PCR for human recombinant HIV-p24 antigen was indicated to be an available method for early screening of HIV infectors in blood donors.