Early Detection of Human Immunodeficiency Virus Type 1-Specific B-Lymphocyte-Derived Antibodies in a High-Risk Population |
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| Authors: | Odd Odinsen David Parker Frans Radebe Mikey Guness David A Lewis |
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| Affiliation: | PlasmAcute AS, Bergen, Norway,1. Novel Consulting Ltd., Dartford, United Kingdom,2. Sexually Transmitted Infections Reference Centre, National Institute for Communicable Diseases, Johannesburg, South Africa,3. Department of Internal Medicine, University of the Witwatersrand, Johannesburg, South Africa,4. Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, South Africa5. |
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| Abstract: | Diagnosis of acute human immunodeficiency virus (HIV) infection, a key driver of the HIV epidemic, remains a public health challenge. The PlasmAcute technology offers an opportunity to detect early anti-HIV antibody responses. B lymphocytes (B cells) were isolated from the blood of seronegative miners in South Africa by using the PlasmAcute method. B-cell lysates and paired sera were tested for anti-HIV-1 antibodies by two different enzyme-linked immunosorbent assays; immunoreactivity was confirmed by Western blotting. All volunteers were tested for HIV type 1 (HIV-1) viral load, p24 antigen, and CD4 count. Sera from HIV-seronegative men who had positive viral loads and were positive for p24 antigen were retested for anti-HIV antibodies after immune complex dissociation. Anti-HIV antibodies were detected in lysates from 16/259 subjects without immunoreactivity in paired sera. Four subjects, one of whom had a positive viral load initially, subsequently seroconverted. Six subjects showed transient anti-HIV-1 antibodies in the lysates and tested negative for all markers at the follow-up. Five subjects without follow-up data initially had lysate-positive/serum-negative samples, and these cases were classified as inconclusive. One subject had lysate antibodies and a detectable viral load but was seronegative at follow-up. In conclusion, lysate-derived anti-HIV-1 B-cell antibodies can be detected prior to seroconversion and earlier than or contemporary with HIV-1 RNA detection.According to the 2006 UNAIDS report on the global AIDS epidemic, an estimated 38.6 million people worldwide were living with human immunodeficiency virus (HIV) at the end of 2005 (31). It was also estimated that 4.1 million became newly infected with HIV and that 2.8 million lost their lives to AIDS in that year. Approximately 10% of the world''s population lives in sub-Saharan Africa, which is home to almost 24.5 million people with the virus, or 64% of all people living with HIV. UNAIDS estimates that 2.7 million became newly infected in this region in 2005 (31). A considerable number of new HIV infections are transmitted by recent HIV seroconverters (6, 23, 25, 26).Early diagnosis of HIV infection is important, as it allows appropriate clinical management and counseling of patients in order to prevent further sexual transmission of HIV to partners (11, 24). It is also important in special situations, for example, screening blood for transfusion (10, 19). Access to reliable test systems for diagnosis of HIV infection at the earliest possible stage is necessary for effective prevention of transmission, early intervention, access to antiviral therapy, surveillance, and blood safety.The enzyme-linked immunospot assay is a well-established method for the enumeration of antibody-secreting cells and study of spontaneous secretion of antibodies (4, 7, 8, 12). In this study, we utilized the PlasmAcute technology to detect anti-HIV-1 antibodies in B-cell lysates before they are detected in serum. This technology is based on the observation that B cells from peripheral blood contain functional antibodies elicited by an infectious agent or vaccine, and these antibodies can be measured before they can be detected in plasma (14, 22). This allows a narrowing of the “window period” between immunological stimulation and seroconversion. The technology involves initial capture enrichment and isolation of B cells from a peripheral-whole-blood sample by using paramagnetic polystyrene beads coated with monoclonal anti-CD19 antibodies followed by subsequent lysis and testing of the lysate in an appropriate immunoassay (22).(The data in this paper were presented in put at the joint meeting of the 17th Meeting of the International Society for Sexually Transmitted Diseases Research and the 10th World Congress of the International Society against Sexually Transmitted Infections, Seattle, WA, 29 July to 1 August 2007 [26a].) |
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