title: Evaluation of the limiting antigen avidity EIA (LAg) in people who inject drugs in Greece.
abstract: This analysis assessed the utility of the limiting antigen avidity assay (LAg). Samples of people who inject drugs (PWID) in Greece with documented duration of HIV-1 infection were tested by LAg. A LAg-normalized optical density (ODn) ⩽1·5 corresponds to a recency window period of 130 days. The proportion true recent (PTR) and proportion false recent (PFR) were estimated in 28 seroconverters and in 366 samples collected >6 months after HIV diagnosis, respectively. The association between LAg ODn and HIV RNA level was evaluated in 232 persons. The PTR was 85·7%. The PFR was 20·8% but fell to 5·9% in samples from treatment-naive individuals with long-standing infection (>1 year), and to 0 in samples with the circulating recombinant form CRF35 AD. A LAg-based algorithm with a PFR of 3·3% estimated a similar incidence trend to that calculated by analyses based on HIV-1 seroconversions. In recently infected persons indicated by LAg, the median log10 HIV RNA level was high (5·30, interquartile range 4·56-5·90). LAg can help identify highly infectious HIV(+) individuals as it accurately identifies recent infections and is correlated with the HIV RNA level. It can also produce reliable estimates of HIV-1 incidence.
authors: Medical School, University of Cyprus, Nicosia, Cyprus.|National Development and Research Institutes (NDRI), Transmission Reduction Intervention Project (Athens site), New York, USA.|Hellenic Centre for Disease Control and Prevention, Amarousio, Greece.
authors: G K
authors: GK
authors: Nikolopoulos
authors: Department of Hygiene, Epidemiology and Medical Statistics, Medical School, University of Athens, Athens, Greece.
authors: A
authors: A
authors: Katsoulidou
authors: Department of Hygiene, Epidemiology and Medical Statistics, Medical School, University of Athens, Athens, Greece.
authors: M
authors: M
authors: Kantzanou
authors: Department of Hygiene, Epidemiology and Medical Statistics, Medical School, University of Athens, Athens, Greece.
authors: C
authors: C
authors: Rokka
authors: Hellenic Centre for Disease Control and Prevention, Amarousio, Greece.
authors: C
authors: C
authors: Tsiara
authors: Department of Hygiene, Epidemiology and Medical Statistics, Medical School, University of Athens, Athens, Greece.
authors: V
authors: V
authors: Sypsa
authors: Department of Hygiene, Epidemiology and Medical Statistics, Medical School, University of Athens, Athens, Greece.
authors: D
authors: D
authors: Paraskevis
authors: First Department of Internal Medicine, Laiko General Hospital, University of Athens, Athens, Greece.
authors: M
authors: M
authors: Psichogiou
authors: National Development and Research Institutes (NDRI), New York, USA.
authors: S
authors: S
authors: Friedman
authors: Department of Hygiene, Epidemiology and Medical Statistics, Medical School, University of Athens, Athens, Greece.
authors: A
authors: A
authors: Hatzakis
mesh_terms: D000328:Adult; D000915:Antibody Affinity; D003951:Diagnostic Errors; D005260:Female; D006115:Greece; D015483:HIV Antibodies / Q000097:blood*; D015658:HIV Infections / Q000175:diagnosis*; D006801:Humans; D007124:Immunoenzyme Techniques / Q000379:methods*; D008297:Male; D012367:RNA, Viral / Q000097:blood; D015819:Substance Abuse, Intravenous / Q000150:complications*; D019562:Viral Load
chemical_list: D015483:HIV Antibodies; D012367:RNA, Viral
keywords: Drug injectors; HIV; LAg; incidence; recent infection