Posting #1 - Increased replication of HIV at TB sites

I realize this is an older article, but I wanted to start here to be able to expound on the theme of the synergy between HIV and TB. Studies over the past dozen years have been exploring the increased replication of HIV that occurs at site of active TB infection.

30 patients with a co-infection of pleural TB and HIV-1 were studied as a higher prevalence of pleural TB has been associated of HIV-1 and is less likely to be resolved in patients with pleural TB.

Several factors were found by this study to indicate that pleural space may be a reservoir for HIV-1 and aid in its replication during a TB infection. First, the study found that HIV-1 viral load and HIV-1 transcriptional elements were higher in both pleural cellular and extracellular spaces as compared to blood cellular and extracellular spaces, respectively. This was independent of plasma CD4 count. TNF-α, which is known to induce HIV-1 replication, was also greatly increased in pleural fluid as compared to plasma. In the pleural space, β-chemokines, a chemoattractant of monocytes, that act as a competitor for attachment site CCR5 were at reduced levels, while MCP-1, a β-chemokine that attaches to CCR-2 instead, was at an elevated level. In addition, CCR5 was upregulated in the mononuclear cells of the pleural space in the presence of TB. All of these findings show an enhanced activation of HIV-1 in the presence of pleural TB.

This study is the one of the baseline studies for research into inner workings of the interaction between these two diseases. This line of research is also giving us valuable information into each of the diseases separately.

Tracy