title: Cellular levels of HIV unspliced RNA from patients on combination antiretroviral therapy with undetectable plasma viremia predict the therapy outcome.
abstract: BACKGROUND
  Combination antiretroviral therapy (cART), the standard of care for HIV-1 infection, is considered to be successful when plasma viremia remains below the detection limit of commercial assays. Yet, cART fails in a substantial proportion of patients after the apparent success. No laboratory markers are known that are predictive of cART outcome in initial responders during the period of undetectable plasma viremia.
  
  
  RESULTS
  Here, we report the results of a retrospective longitudinal study of twenty-six HIV-infected individuals who initially responded to cART by having plasma viremia suppressed to <50 copies/ml. Eleven of these patients remained virologically suppressed, whereas fifteen experienced subsequent cART failure. Using sensitive methods based on seminested real-time PCR, we measured the levels of HIV-1 proviral (pr) DNA, unspliced (us) RNA, and multiply spliced RNA in the peripheral blood mononuclear cells (PBMC) of these patients at multiple time points during the period of undetectable plasma viremia on cART. Median under-therapy level of usRNA was significantly higher (0.43 log(10) difference, P = 0.0015) in patients who experienced subsequent cART failure than in successfully treated patients. In multivariate analysis, adjusted for baseline CD4(+) counts, prior ART experience, and particular cART regimens, the maximal usRNA level under therapy was the best independent predictor of subsequent therapy failure (adjusted odds ratio [95% CI], 24.4 [1.5-389.5], P = 0.024). The only other factor significantly associated with cART failure was prior ART experience (adjusted odds ratio [95% CI], 12.3 [1.1-138.4], P = 0.042). Levels of usRNA under cART inversely correlated with baseline CD4(+) counts (P = 0.0003), but did not correlate with either baseline usRNA levels or levels of prDNA under therapy.
  
  
  CONCLUSIONS
  Our data demonstrate that the level of HIV-1 usRNA in PBMC, measured in cART-treated patients with undetectable plasma viremia, is a strong predictive marker for the outcome of therapy.
authors.affiliation: Department of Medical Microbiology, Laboratory of Experimental Virology, Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center of the University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Alexander O
authors.initials: AO
authors.lastname: Pasternak
authors.forename: Suzanne
authors.initials: S
authors.lastname: Jurriaans
authors.forename: Margreet
authors.initials: M
authors.lastname: Bakker
authors.forename: Jan M
authors.initials: JM
authors.lastname: Prins
authors.forename: Ben
authors.initials: B
authors.lastname: Berkhout
authors.forename: Vladimir V
authors.initials: VV
authors.lastname: Lukashov
mesh_terms: D000328:Adult; D023241:Antiretroviral Therapy, Highly Active; D018791:CD4 Lymphocyte Count; D015658:HIV Infections / Q000097:blood / Q000188:drug therapy / Q000821:virology*; D015497:HIV-1 / Q000235:genetics*; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000378:metabolism* / Q000821:virology; D008875:Middle Aged; D012326:RNA Splicing / Q000235:genetics*; D012367:RNA, Viral / Q000235:genetics*; D017211:Treatment Failure; D016896:Treatment Outcome; D014766:Viremia / Q000097:blood*
chemical_list: D012367:RNA, Viral