Clinical usefulness of HCV core antigen assay for the management of patients with chronic hepatitis C.

AIM: The study aimed to evaluate the clinical utility of the chemiluminescent HCV core Ag test compared to viral load assessment in the management of patients with chronic hepatitis C. METHODS: A retrospective study was performed at a tertiary-care infectious diseases hospital on samples collected from anti-HCV positive patients. Seventy-six samples were tested with the Architect HCV core Antigen kit and Cobas AmpliPrep/Cobas Taqman HCV kit. The HCV Ag test accuracy was estimated using data from all the HCV RNA tested samples received between January 2011 and December 2012. RESULTS: The HCV Ag test showed a good correlation between the logarithmic values of HCV RNA and HCV Ag (R=0.98), with a 100% specificity and PPV, but with reduced sensitivity for viral loads lower than 1,000 UI/mL. In a model using data from 2,478 HCV RNA tested samples and a cut-off of the Ag assay corresponding to 1,000 UI/mL HCV RNA, the Ag test would have a sensitivity of 82.4%, a NPV of 80.9% and a high specificity and PPV (100%) compared to the viral load. The sensitivity would be higher for baseline evaluation compared to on-treatment samples (98.5 vs. 50%). The highest NPV (98%) would be obtained at 48 and 72 weeks after the initiation of treatment, with a sensitivity of 88.2% and 96.1%, respectively. CONCLUSION: The Architect HCV core Ag assay might be an alternative for the diagnosis of active HCV infection if molecular tests are not available, and a useful method for the evaluation of sustained virological response in treated patients.

Detection of resistance to second-line antituberculosis drugs by use of the genotype MTBDRsl assay: a multicenter evaluation and feasibility study.

The rate of multidrug-resistant (MDR) and extensively drug-resistant (XDR) tuberculosis (TB) has been steadily increasing in countries of the former USSR. The availability of rapid and reliable methods for the detection of drug resistance to second-line drugs is vital for adequate patient management. We evaluated the performance of the Genotype MTBDRsl assay compared to that of phenotypic drug susceptibility testing (Becton Dickinson Bactec MGIT 960 system) with a test panel of 200 Mycobacterium tuberculosis isolates at four sites in Eastern Europe. The interpretability of the Genotype MTBDRsl assay was over 95%. The sensitivity for the detection of resistance to fluoroquinolones, ethambutol, amikacin, and capreomycin varied between 77.3% and 92.3%; however, it was much lower for kanamycin (42.7%). The sensitivity for the detection of XDR TB was 22.6%. The test specificity was over 82% for all drugs. The assay presents a good screening tool for the rapid detection of resistance to individual second-line drugs and can be recommended for use in countries with a high burden of MDR/XDR TB. The sensitivity for the detection of kanamycin resistance needs improvement.

Polymorphisms and resistance mutations in the protease and reverse transcriptase genes of HIV-1 F subtype Romanian strains.

OBJECTIVE: To evaluate the prevalence of resistance mutations in the genome of HIV-1 F subtype strains isolated from Romanian antiretroviral (ARV) treatment-naïve patients and to assess the phylogenetic relatedness of these strains with other HIV-1 strains. METHODS: Twenty-nine HIV-1 strains isolated from treatment-naïve adolescents (n=15) and adults (n=14) were included in this study. Resistance genotyping was performed by using Big Dye Terminator chemistry provided by the ViroSeq Genotyping System. The sequences of the protease and reverse transcriptase genes were aligned (ClustalW) and a phylogenetic tree was built (MEGA 3 software). For subtyping purposes, all the nucleotide sequences were submitted to the Stanford database. RESULTS: All the studied strains were found to harbor accessory mutations in the protease gene. The most frequent mutation was M36I (29 of 29 strains), followed by L63T, K20R, and L10V. The number of polymorphisms associated with protease inhibitor resistance was different for the two age groups. Intraphylogenetic divergence was greater for adults than for adolescents infected in childhood. All the strains were found to belong to the F1 subtype. The phylogenetic analysis revealed that Romanian strains clustered together, but distinctly from F1 HIV-1 strains isolated in other parts of the world (Brazil, Finland, and Belgium). CONCLUSION: Protease secondary mutations are present with high frequency in the HIV-1 F subtype strains isolated from Romanian ARV treatment-naïve patients, but no major resistance mutations were found.