Unexpected low-level viremia among HIV-infected Ugandan adults with untreated active tuberculosis

Mollicutes/HIV Coinfection and the Development of AIDS: Still Far from a Definitive Response

Background. Mycoplasmas are known to cause various infections in humans, mainly in the respiratory and urogenital tracts. The different species are usually host-specific and cause diseases in well-defined sites. New species have been isolated, including those from HIV-infected persons. Summary. Its in vitro properties, combined with clinical findings, have led to the hypothesis that these microorganisms may act as cofactors of HIV in AIDS development. Even today this point of view is quite polemic among infectious disease specialists and many aspects remain to be clarified, in contrast to what happens, for instance, with HIV/Mycobacterium tuberculosis coinfection. Dozens of papers have been published covering aspects of Mollicutes/HIV coinfection, but they add little to no information about the putative contribution of Mollicutes to the evolution of AIDS. Very few researchers have devoted their efforts to trying to answer this question, which remains open. In this review, we discuss the evidences that may support this statement in the light of current knowledge in the field of mycoplasmology.

Impact of tuberculosis treatment on CD4 cell count, HIV RNA, and p24 antigen in patients with HIV and tuberculosis

OBJECTIVES

To describe HIV RNA levels during tuberculosis (TB) infection in patients co-infected with TB and HIV. Moreover, to examine the p24 antigen profile during TB treatment.

METHODS

We examined the changes in CD4 cell count, HIV RNA, and p24 levels during anti-tuberculous therapy in a group of TB/HIV-1 co-infected and HIV-untreated patients from Guinea-Bissau.

RESULTS

A total of 365 TB patients were enrolled, of whom 76 were co-infected with HIV-1 and 19 were dually infected with HIV-1 + HIV-2. No significant changes in CD4, HIV RNA, or p24 levels were found during 8 months of TB treatment. HIV RNA levels correlated well with p24 (Spearman's R(2)=0.52, p<0.00001) and both markers were strong predictors of mortality. Initial HIV RNA levels correlated with a clinical TB severity index--the TBscore (Spearman's R(2)=0.23, p=0.02)--and the TBscore decreased dramatically during TB treatment although HIV RNA levels remained unchanged.

CONCLUSION

We found no significant changes in CD4, HIV RNA, or p24 antigen levels during 8 months of TB treatment among TB/HIV co-infected individuals, who did not receive antiretroviral treatment. The markers were unaffected by a strong improvement in TBscore and all three markers showed predictive capacity for mortality risk.

Tuberculosis treatment in HIV infected Ugandans with CD4 counts>350 cells/mm reduces immune activation with no effect on HIV load or CD4 count

Background

Both HIV and TB cause a state of heightened immune activation. Immune activation in HIV is associated with progression to AIDS. Prior studies, focusing on persons with advanced HIV, have shown no decline in markers of cellular activation in response to TB therapy alone.

Methodology

This prospective cohort study, composed of participants within a larger phase 3 open-label randomized controlled clinical trial, measured the impact of TB treatment on immune activation in persons with non-advanced HIV infection (CD4>350 cells/mm³) and pulmonary TB. HIV load, CD4 count, and markers of immune activation (CD38 and HLA-DR on CD4 and CD8 T cells) were measured prior to starting, during, and for 6 months after completion of standard 6 month anti-tuberculosis (TB) therapy in 38 HIV infected Ugandans with smear and culture confirmed pulmonary TB.

Results

Expression of CD38, and co-expression of CD38 and HLA-DR, on CD8 cells declined significantly within 3 months of starting standard TB therapy in the absence of anti-retroviral therapy, and remained suppressed for 6 months after completion of therapy. In contrast, HIV load and CD4 count remained unchanged throughout the study period.

Conclusion

TB therapy leads to measurable decreases in immune activation in persons with HIV/TB co-infection and CD4 counts >350 cells/mm³.