Poizot-Martin I 1, Marimoutou C 1, Drogoul-Vey M-P 1, Tamalet C 2, Dignat-George F 3, Colson P 2, Brunnet C 3, Grégoire R 4, Pradel V 4, Gastaut JA1. 1- CISIH-Sud, Département de Recherche Clinique, Hôpital Sainte-Marguerite, Marseille; 2- Laboratoire de Virologie, Hôpital de la Timone, Marseille; 3- Laboratoire d’Hématologie, Hôpital de La  Conception, Marseille; 4- Departement d'Information Médicale, Hôpital Sainte-Marguerite, Marseille (France).

Background: To assess proportion of persistent RNAcell and it association with immune recovery  in  82  HIV-infected patients with sustained undetectable plasma viral load. Material and Methods: Cross-sectional study. Plasma HIV-RNA undetectability was <200 copies/mL (Roche Amplicor Test). Intracellular HIV-RNA level (RNAcell) was measured on peripheral blood mononuclear cells (PBMC, threshold detection: 50 copies per million PBMC). Naive CD4+T cells were characterized by double expression of CD45RA/CD62L and functionality by CD28. Activation markers of CD8 Tcells were HLADR and CD38. Results: Patients were 74% pretreated and 26% naive. The average CD4 cell count, at initiation of the treatment responsible of plasma RNA withdrawal, were 230 and 332 respectively (p=0.01). The average duration of plasma undetectability was 24 (+/-5) months in both groups. Compared to pretreated, naive patients presented more naive cells (p=0.04). The RNAcell was over detection in 34 patients (41.5%). These patients did not differ of others according to initial plasma RNA, plasma RNA undetectability duration, and proportion of pretreated patients. Initial CD4 cell count tended to be lower (236/mm3+/-170 versus 313/mm3+/-233, p=0.09) and proportion of AIDS cases higher (29% vs 12%, p=0.06). Immune characteristics associated with RNA cell detection were a lower proportion of naive (CD45RA: p=0.01) and functional (CD28; p=0.02) CD4+ cells and an increase of the CD8 CD38 marker (p=0.05). Conclusion: RNAcell detection may persist in patients with sustained plasma RNA level. In this case the immune restauration is lower. The lower count of CD4+ at therapy initiation and the higher proportion of AIDS cases may also had influenced restauration in patients with persistent RNAcell.