HIV and ID Observations

The single case of HIV cure following allogeneic bone marrow transplant is in the news again, this time because of data just presented at “The International Workshop on HIV and Hepatitis Virus Drug Resistance and Curative Strategies” (formerly known as the “HIV Resistance Workshop” — how’s that for rebranding?).

I’m not at the meeting, which is too bad since they often have it in splendid locations.

But from what I gather based on the report, here are the key findings in the study:

• The patient remains off antiretroviral therapy, with a normal CD4 cell count
• He has generously submitted multiple specimens for research analyses at multiple different time points
• Highly sensitive assays of various sorts have been performed at several labs
• HIV RNA has been detected in plasma in 2 (of 4) labs from 3 different time points; levels are lower than those typically seen in virologically suppressed patients on ART
• HIV DNA was detected in a rectal biopsy sample by one lab
• No HIV has been detected in CSF or peripheral blood mononuclear cells
• No replication-competent HIV has been isolated

My gut feeling is that the findings are potentially real, but unlikely to be of much clinical significance if virus can only be detected intermittently by special assays, especially since he’s been off all HIV treatment for more than 5 years.

But they may not be real — we need to remember that a false positive test result is more likely when the test’s sensitivity is cranked up and it’s performed multiple times.

Or as more colorfully put by Doug Richman:

If you do enough cycles of PCR, you can get a signal in water for pink elephants.

And if this interesting presentation tells us anything, it’s that defining success in any study of an HIV cure strategy is going to be very, very difficult.