Evaluation of the limiting antigen avidity EIA (LAg) in people who inject drugs in Greece.

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.

Development and assessment of a novel real-time PCR assay for quantitation of hepatitis D virus RNA to study viral kinetics in chronic hepatitis D.

Hepatitis delta virus (HDV) infection is a usually severe type of viral hepatitis associated with increased mortality and rapid evolution to cirrhosis. Currently, treatment is limited to extended interferon administration and measurement of HDV RNA blood levels is essential to judge the response. The aim of this study was to develop a highly sensitive and reproducible real-time reverse transcriptase-polymerase chain reaction (real-time RT-PCR) for the quantitation of circulating HDV RNA of all clades (1-8), and assess its usefulness in the follow-up of patients. The amplification was combined with molecular beacon technology using the LightCycler 2.0 system. The assay was specific and showed linearity over a wide range from 13 to 13 × 10(10) copies/mL. The 95% detection limit was 43.2 copies/mL. Intra-assay reproducibility, as expressed by the coefficient of variation, ranged from 1.84 to 18.61%, whereas the corresponding estimates for the inter-assay variability ranged from 0.57 to 10.18%. Finally, the dynamic profiles of six patients regarding virological (HDV RNA, HBV DNA), biochemical and serological data were constructed. We were able to observe that most patients who were treated with an interferon-based regime showed a significant reduction in delta viremia. In conclusion, our real-time RT-PCR for HDV RNA quantification combines high sensitivity and reproducibility in a high dynamic range, can provide important information for patient management and can be a useful tool for monitoring the response to antiviral therapies.

Seroepidemiology of human herpesvirus 8 (HHV-8) infection in injecting drug users.

A cross-sectional study was carried out in injecting drug users (IDUs) from Greece to assess the seroprevalence of human herpesvirus 8 (HHV-8) and to identify potentially associated risk factors. A total of 288 IDUs were tested for K8.1 antibodies to HHV-8 lytic antigen. Associations between HHV-8 serostatus and potential risk factors were examined using univariate and multivariate logistic regression analysis. Seroprevalence of HHV-8 was 24.3% (95% CI 19.5-29.7), increasing with age from 19.4% in those aged <30 years to 52.9% in those aged 40 years (P for trend=0.003). No statistically significant associations between HHV-8-positive status and gender, educational level, age at first drug injection, needle sharing, number of imprisonments, complications from drug overdose, HIV and HCV were observed. In the multivariate logistic regression analysis, older age (40 vs. <40 years, OR 3.30, 95% CI 1.14-9.56) and report of septicaemia/abscess (yes vs. no, OR 1.80, 95% CI 1.01-3.18) were each independently associated with higher HHV-8 seroprevalence. HHV-8 is highly prevalent in the IDU population in Greece. The independent association between HHV-8 and reported abscess or septicaemia supports the hypothesis that poor hygiene conditions in the setting of drug injection may contribute to HHV-8 transmission.