I NDoye | PubMed Health

PubMed1999

Human immunodeficiency virus type 1 subtypes differ in disease progression.

At least 10 different genetic human immunodeficiency virus type 1 (HIV-1) subtypes (A-J) are responsible for the AIDS pandemic. Much of the understanding of HIV-1 disease progression derives from studies in the developed world where HIV infection is almost exclusively subtype B. This has led many to question whether the properties and consequences of HIV-1 infection can be generalized across subtypes that afflict the majority of infected persons in the developing world. From 1985 to 1997, a prospective study of registered female sex workers in Senegal tracked the introduction and spread of HIV-1 subtypes A, C, D, and G. In clinical follow-up, the AIDS-free survival curves differed by HIV-1 subtype. Women infected with a non-A subtype were 8 times more likely to develop AIDS than were those infected with subtype A (hazard ratio=8.23; P=. 009), the predominant subtype in the study. These data suggest that HIV-1 subtypes may differ in rates of progression to AIDS.

Acquired Immunodeficiency Syndrome↗

PubMed1998

HIV-1 and HIV-2 dual infection: lack of HIV-2 provirus correlates with low CD4+ lymphocyte counts.

OBJECTIVE: We conducted this study to genetically characterize dual infection in individuals demonstrating a dual serological profile. METHODS: All subjects were first evaluated by immunoblot for antibody reactivity to the major viral antigens for HIV-1 and HIV-2. Sera were judged to be dual-seropositive if they reacted with strong and equal intensity with the envelope antigens of both HIV-1 and HIV-2 and were confirmed with type-specific recombinant env peptides. We used nested polymerase chain reaction (PCR) to amplify proviral gag and env sequence from peripheral blood mononuclear cell (PBMC) DNA from HIV-1- and HIV-2-infected individuals. Positive amplification was detected after Southern blot hybridization. RESULTS: Plasmid dilution and mixing showed equivalent sensitivity of HIV-1 and HIV-2 primers that was not altered by heterologous target sequences. The DNA PCR showed 100% sensitivity and specificity for detection of monotypic HIV infection. Serologically defined HIV-dual reactives were evaluated by this assay, with 100% detection in female sex workers (21 out of 21), but only 38.5% detection (five out of 13) in hospitalized patients; all being HIV-1 positive only. The lack of HIV-2 proviral signal was significantly correlated with low CD4+ lymphocyte counts (Pvalue = 0.04). CONCLUSION: The results suggest that HIV dual infection may not be a static condition. Levels of HIV-2 may decrease with disease progression or sequester in tissue reservoirs; our results may also suggest that HIV-1 effectively overgrows HIV-2 in the dually exposed host individual.

Blotting, Southern↗