1. Persistent low-level viremia despite clinically successful antiretroviral therapy appears correlated with more frequent resting CD4+ T cell Infection NM Archin 1, J Anderson 1, KS Keedy 1, KM Barton 1, M Cheema 1, R Sackmann 1, A Wiegand 2, JD Kuruc 1, JJ Eron 1, MS Cohen 1, JM Coffin 2, R Swanstrom 1 and DM Margolis 1 Department of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; 2 NCI HIV Drug Resistance Program, Frederick, MD, USA. Poster : WEPDA101

2. Background Persistent infection of resting CD4+ T cells (RCI)remains a barrier to HIV eradication despite antiretrovial therapy (ART). In approximately 75% individuals, low-level viremia is detectable by sensitive PCR assays despite successful ART. Is RCI a potential source of this viremia?

3. Correlation between low-level viremia and resting cell infection All patients with LLV of < 1 copy were assigned an arbitrary value of 0.5. Purple line indicates the single copy limit of detection of this assay

4. env plasma sequences hypervariable V1-V2 loop plasma sequences env sequences from resting cell outgrowth hypervariable V1-V5 loop sequences from resting cell outgrowth (visit A) hypervariable V1-V5 loop sequences from resting cell outgrowth (visit B) Patient M Similarity of plasma and resting cell outgrowth virus sequences from patient M

5. Conclusions Our study supports the hypothesis that resting CD4 positive T cells are a major source of intermittent low-level viremia, and therapies that target RCI are essential in the effort to eradicate HIV Infection. However, our findings do not exclude other potential cellular sources of low level viremia and explicit identification of these cells will be critical in the effort to purge persistent HIV infection

6. University of North Carolina Chapel Hill Acknowledgements Margolis lab: Daniel Parker Noelle Dahl Liguo Niu Shailesh Choudhary Abigail Lees Sarah Palmer Clinical Coordinators: Jenny Scepanski JoAnn Kuruc Alyssa Sugarbaker Linh Ngo UNC Blood Bank and Staff Our patients Support from: amfAR 107168-44-RGRL, R00046, U54RR024383, AI50410 (UNC CFAR), NIH R01 AI045297, T32 AI07001 and AI07151

8. env plasma sequences env sequences from resting cell outgrowth Patient O Similarity of plasma and resting cell outgrowth virus sequences from patient O: up to 99.87% identity