title: Significance and clinical management of persistent low-level viremia and very-low-level viremia in HIV-1-infected patients.
abstract: A goal of HIV therapy is to sustain suppression of the plasma viral load below the detection limits of clinical assays. However, widely followed treatment guidelines diverge in their interpretation and recommended management of persistent viremia of low magnitude, reflecting the limited evidence base for this common clinical finding. Here, we review the incidence, risk factors, and potential consequences of low-level HIV viremia (LLV; defined in this review as a viremia level of 50 to 500 copies/ml) and very-low-level viremia (VLLV; defined as a viremia level of <50 copies/ml detected by clinical assays that have quantification cutoffs of <50 copies/ml). Using this framework, we discuss practical issues related to the diagnosis and management of patients experiencing persistent LLV and VLLV. Compared to viral suppression at <50 or 40 copies/ml, persistent LLV is associated with increased risk of antiretroviral drug resistance and overt virologic failure. Higher immune activation and HIV transmission may be additional undesirable consequences in this population. It is uncertain whether LLV of <200 copies/ml confers independent risks, as this level of viremia may reflect assay-dependent artifacts or biologically meaningful events during suppression. Resistance genotyping should be considered in patients with persistent LLV when feasible, and treatment should be modified if resistance is detected. There is a dearth of clinical evidence to guide management when genotyping is not feasible. Increased availability of genotypic assays for samples with viral loads of <400 copies/ml is needed.
authors.affiliation: Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland, USA pryscavage@ihv.umaryland.edu.
authors.forename: Patrick
authors.initials: P
authors.lastname: Ryscavage
authors.affiliation: Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA.
authors.forename: Sean
authors.initials: S
authors.lastname: Kelly
authors.affiliation: Division of Infectious Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Jonathan Z
authors.initials: JZ
authors.lastname: Li
authors.affiliation: Division of AIDS, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: P Richard
authors.initials: PR
authors.lastname: Harrigan
authors.affiliation: Division of Infectious Diseases, Northwestern University School of Medicine, Chicago, Illinois, USA.
authors.forename: Babafemi
authors.initials: B
authors.lastname: Taiwo
mesh_terms: D019380:Anti-HIV Agents / Q000493:pharmacokinetics / Q000627:therapeutic use*; D023241:Antiretroviral Therapy, Highly Active; D018988:Bacterial Translocation; D004338:Drug Combinations; D024882:Drug Resistance, Viral; D005838:Genotype; D015658:HIV Infections / Q000188:drug therapy* / Q000473:pathology / Q000821:virology; D015497:HIV-1; D006801:Humans; D012367:RNA, Viral / Q000032:analysis; D012307:Risk Factors; D019562:Viral Load; D014766:Viremia / Q000188:drug therapy* / Q000821:virology
chemical_list: D019380:Anti-HIV Agents; D004338:Drug Combinations; D012367:RNA, Viral
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