In vitro assays show a dissociation of reverse transcriptase activity and core antigen (p24) production in two HIV-1 isolates from a patient receiving long-term treatment with zidovudine (ZDV)
Article Abstract:
Zidovudine (ZDV or AZT) is the only drug approved for use in treating infection with the human immunodeficiency virus (HIV), the agent that causes AIDS. This drug works by entering infected cells and being incorporated into the viral genetic material, blocking replication of the virus. AZT treatment has helped prolong the lives of patients with AIDS. However, it can have a number of severe side effects which can inhibit its use, and its effectiveness diminishes over time. This decreased effectiveness may be caused by the development of resistant strains of the virus or by dormant virus becoming partially or fully active, or both. When AZT is initially given, signs of HIV infection decrease for about the first six months, then begin to reappear. One indication of HIV replication is increased p24 production. This is a protein produced by the virus that can be detected using antigen tests. This study examined p24 production in an HIV-infected patient who received long-term treatment with AZT, and compared it with reverse transcriptase (RT) activity. RT is an enzyme necessary for full replication of HIV, whereas p24 may be produced without fully infectious viruses being produced. Infected cells were obtained from the patient and cultured. RT activity and p24 production were measured with and without AZT. Results showed that p24 production was high when AZT was present, but the RT activity remained low when AZT was present. These findings indicate that p24 production and full viral replication, as indicated by RT activity, can be independent of each other. This could mean that AZT is still effective in preventing replication of HIV while p24 production is high, and thus p24 production may not always indicate that AZT is no longer effective. (Consumer Summary produced by Reliance Medical Information, Inc.)
Publication Name: Journal of Acquired Immune Deficiency Syndromes
Subject: Health
ISSN: 0894-9255
Year: 1991
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Kinetics of appearance of neutralizing antibodies in 12 patients with primary or recent HIV-1 infection and relationship with plasma and cellular viral loads
Article Abstract:
The drop in blood levels of HIV shortly after infection with the virus does not appear to be a result of neutralizing antibodies. Researchers took blood samples every month from 12 HIV-infected people and tested them for the presence of HIV and neutralizing antibodies against the virus. HIV levels were also measured in mononuclear blood cells. Six of the volunteers had been infected within the past 4 weeks (primary infection) and six between 4 and 24 weeks (recent infection). Only one person with primary infection had neutralizing antibodies at three weeks. Most of the others did not produce neutralizing antibodies until six or eight weeks after infection. Nevertheless, the high blood levels of HIV in most of the volunteers dropped during the first six months. In many cases, blood levels of HIV dropped before neutralizing antibodies were produced. But the viral load in mononuclear blood cells did not drop substantially.
Publication Name: Journal of Acquired Immune Deficiency Syndromes and Human Retrovirology
Subject: Health
ISSN: 1077-9450
Year: 1996
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Mechanism of virologic failure after substitution of a protease inhibitor by nevirapine in patients with suppressed plasma HIV-1 RNA
Article Abstract:
HIV can become resistant to the non-nucleoside reverse transcriptase inhibitor nevirapine if the patient took other AIDS drugs that were not completely suppressing the virus. In a study of 34 patients, none of those who had taken a protease inhibitor developed resistance to nevirapine but 41% of those who had taken other AIDS drugs developed resistance to nevirapine.
Publication Name: Journal of Acquired Immune Deficiency Syndromes (1999)
Subject: Health
ISSN: 1525-4135
Year: 2001
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