icon-folder.gif   Conference Reports for NATAP  
  52nd ICAAC Interscience Conference on
Antimicrobial Agents and Chemotherapy
September 9-12, 2012, San Francisco
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Persistent Low-level Viraemia in HIV-1-infected Patients: Swiss HIV Cohort Study
  Reported by Jules Levin
52nd ICAAC Sept 9-12 2012 SF
N. Boillat-Blanco1, K.E.A. Darling1, F. Schöni-Affolter2, M. Rougemont3, R. Fulchini4, E. Bernasconi5, D. Vuichard6, M. Aouri7, O. Clerc1, H. Furrer8, H.F. Günthard9, M. Cavassini1 1 Infectious Diseases (ID) Service, Lausanne University Hospital, Switzerland; 2 Data Coordination Centre, Swiss HIV Cohort, Lausanne, Switzerland; 3 Division of ID, Geneva University Hospital, Switzerland; 4 Division of ID, Cantonal Hospital, St. Gallen, Switzerland; 5 Division of Infectious Diseases, Hospital of Lugano, Switzerland; 6 Division of ID and Hospital Epidemiology, University Hospital Basel, Switzerland; 7 Division of Clinical Pharmacology and Toxicology, University Hospital of Lausanne, Switzerland 8 University Clinic of ID, University Hospital Bern, Switzerland; 9 Division of ID and Hospital Epidemiology, University Hospital Zurich, Switzerland.
Program Abstract
Low-level viraemia (LLV) may arise in patients with previously undetectable HIV viral loads (VL) on cART. It is important to know the implications of LLV and the benefit of cART-change.
Methods: Case-control study. Patients enrolled from1 January 2000 to 31 December 2010, undetectable for ≥24 weeks on cART, presenting a persistent LLV (VL 21-400 copies/mL on ≥3 consecutive plasma samples with ≥8 weeks between first and last analyses) without cART-change were compared to controls with ≥3 consecutive VL values ≤20 copies/mL for ≥32 weeks without cART-change.
Results: We studied 179 patients with LLV and 5389 controls. Compared to controls, patients with LLV had worse cART adherence (aOR[95%CI] 1.9[1-3.3]) and were less often on NNRTI cART (aOR 0.5[0.3-0.8]). More patients had LLV after 2008 (aOR 6.4[3.5-11.4)]). Most patients (n=102; 66%) still had LLV at 48 weeks while 19 (12%) presented virological failure (VF=VL>400copies/mL). Predictors of VF were diabetes (aOR 12.6[2-81]) and suboptimal adherence (aOR 5.3[1.5-18.9]). No patient with very LLV (VLLV=21-49 copies/mL; N=26) experienced VF. 48 weeks after last LLV, 51 (28%) patients changed cART; predictors were being on NRTI only regimens (aOR 9.6[1.6-6.7)]), nadir CD4 count ≤200 (aOR 5[1.4-18.3]) and LLV onset after 2008 (aOR 3.8[1.1-12.3]). Of 43 patients with cART-change, 63% had undetectable VLs by 24 weeks compared to 33% without change (P=0.001). VF occurred in 9% post-change and in 12% on unchanged cART (P=0.8).
Conclusions: Progression to VF occurs in a minority of patients up to a year post-LLV and in no patient with VLLV. cART change is driven mainly by cART regimen at LLV onset and availability of new classes of ARV drug. Whilst the majority of changing patients achieved undetectable VLs, change did not affect the rate of VF.