Does plasma HIV RNA predict outcome in a cohort of treated HIV-infected individuals followed over 3 years?

Background: Despite reductions in AIDS illness and mortality, it is increas ingly apparent that a significant proportion of individuals treated with co mbination antiretroviral (cARV) therapy have continuing or recrudescent HIV RNA in plasma. The predictive value of plasma HIV RNA in treated individua l remains uncertain and rates of and risk factors for adverse outcomes such as hospitalisation, opportunistic infections and deaths are needed. Object ives: The objectives of this study were to establish a retrospective cohort of individuals treated with cARVs, to assess factors associated with detec table HIV RNA and to determine rates of and risk factors for hospitalisatio n, opportunistic infection and mortality over 3 years of follow-up. Study d esign: All individuals treated at The Alfred Hospital, Melbourne, Victoria between January and June 1997 who had had plasma HIV RNA measured were incl uded in the retrospective cohort. Clinical, virological and hospitalisation data were recorded and validated by cross-reference with electronically st ored laboratory, hospital activity and state notification databases. Outcom e was assessed at October 2000. Results: Amongst the 555 individuals tested , 438 (60.7%) had detectable ( > 500 copies/ml) HIV RNA (bDNA assay, versio n 2) at baseline. The overall mortality rate was 5.5 per 100 person years; the AIDS rate 1.99 per 100 person years and hospitalisation rate 16.4 per 1 00 person years. Risk factors for death in this population identified by un ivariate analysis were HIV RNA concentration at baseline and at follow-up O ctober 2000, nadir and most recent CD4 lymphocyte number, not receiving cAR V as initial treatment, total number of ARV agents and number of changes in ARV per year, developing AIDS and being hospitalised during follow-up. In a multivariate model, the most recent CD4 lymphocyte number, the number of different ARVs per year and having more than one hospitalisation remained p redictive of death. Conclusions: HIV RNA remained detectable in the majorit y (60.7%) of this treatment-experienced population over 3 years, yet mortal ity rate remained relatively low at 5.5 per 100 person years. Factors assoc iated with death were immunological (CD4 lymphocyte number) and treatment r elated (numbers of changes of ARV and hospitalisation) rather than virologi cal (HIV RNA) in this cohort. We believe hospitalisation rates may be a use ful marker of HIV disease in cARV treated populations and may identify grou ps at risk of poorer outcome and in need of intervention. (C) 2001 Elsevier Science B.V. All rights reserved.