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    ABSTRACT: HIV-1 and HIV-2 infections have important differences in epidemiology, clinical progression and transmission. Studies of the less transmissible and pathogenic HIV-2 have revealed some intriguing facts, indicating that it is less prone to replicate and perhaps can evoke a more efficient or long-lasting immune response than HIV-1 in the human host. Several crucial aspects of HIV-2 infection are still insufficiently characterised. However, there is now convincing evidence that plasma viral load is considerably lower for HIV-2 than for HIV-1, despite similar proviral (DNA) loads for the two viruses. There are reports on lower levels of apoptosis for HIV-2, possibly indicating a lower level of harmful immune activation. Several studies have also shown that vigorous HIV-2 specific immune responses can be detected, especially during the asymptomatic phase of HIV-2 infection. This includes humoral as well as cell-mediated immunity (CMI). The neutralising antibody response appears to be broader and the CMI may be more efficient for HIV-2 as compared to HIV-1. However, comparative studies in the same population groups on HIV-1 and HIV-2 immunity are scarce and difficult to perform. Nevertheless, by increasing our knowledge about how HIV-2 is contained to a higher degree than HIV-1, clinically as well as epidemiologically, we may gain knowledge that is useful in a wider perspective in our struggle to curb the devastating HIV/AIDS epidemic.
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    AIDS Research and Human Retroviruses 09/1995; 11(8):985-8. DOI:10.1089/aid.1995.11.985 · 2.46 Impact Factor
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    ABSTRACT: Few and inconclusive results have been presented regarding the influence of human T-lymphotropic virus 1 (HTLV-1) infection on the risk of acquiring tuberculosis (TB). In 1994-1997, we performed a prospective study on hospitalized adult patients with pulmonary TB in Guinea-Bissau and compared the clinical outcome in HIV-2 and HIV-negative patients. We determined the prevalence of HTLV-1 in all patients screened and diagnosed with TB in that study and compared the infection rate with a serosurvey of HTLV-1 in a population sample from a community-based study conducted at the same time and in the same city. In the TB group, a total of 32 (11.4%) of 280 patients were positive for HTLV-1. This was significantly higher compared with the population-based group in which 74 (3.5%) of 2117 were HTLV-1 positive [crude odds ratio (OR) = 3.6; 95% confidence interval (CI) 2.2 to 5.6, P < 0.001]. However, in a logistic regression analysis controlling for age, gender, and HIV result, the difference was no longer significant (OR = 1.61; 95% CI 0.95 to 2.70, P = 0.074). In HIV-negative patients, no association was found between HTLV-1 and TB (OR = 1.18; 95% CI 0.48 to 2.89, P = 0.71), whereas a significant association was found in HIV-positive patients (OR = 2.41; 95% CI 1.26 to 4.61, P = 0.008). The immunosuppressive effect of HTLV-1 alone was not enough to increase the risk of TB in a highly endemic country, but HTLV-1 increased the risk of TB among HIV-infected individuals.
    JAIDS Journal of Acquired Immune Deficiency Syndromes 08/2008; 48(5):607-10. DOI:10.1097/QAI.0b013e31817efb83 · 4.39 Impact Factor