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Occult HBV infection (OBI) is a threat for the safety of blood-supply, and has been associated with the onset of HBV-related hepatocellular carcinoma and lymphomagenesis. Nevertheless, genetic markers in HBsAg (particularly in D-genotype, the most common in Europe) significantly associated with OBI in vivo are missing. Thus, the goal of this study is to define: (i) prevalence and clinical profile of OBI among blood-donors; (ii) HBsAg-mutations associated with OBI; (iii) their impact on HBsAg-detection. OBI was searched among 422,278 blood-donors screened by Nucleic-Acid-Testing. Following Taormina-OBI-definition, 26 (0.006%) OBI-patients were identified. Despite viremia <50IU/ml, HBsAg-sequences were obtained for 25/26 patients (24/25 genotype-D). OBI-associated mutations were identified by comparing OBI-HBsAg with that of 82 chronically-infected (genotype-D) patients as control. Twenty HBsAg-mutations significantly correlated for the first time with OBI. By structural analysis, they localized in the major HBV B-cell-epitope, and in HBsAg-capsid interaction region. 14/24 OBI-patients (58.8%) carried in median 3 such mutations (IQR:2.0-6.0) against 0 in chronically-infected patients. By co-variation analysis, correlations were observed for R122P+S167L (phi=0.68, P=0.01), T116N+S143L (phi=0.53, P=0.03), and Y100S+S143L (phi=0.67, p<0.001). Mutants (obtained by site-directed mutagenesis) carrying T116N, T116N+S143L, R122P, R122P+Q101R, or R122P+S167L strongly decreased HBsAg-reactivity (54.9±22.6S/CO, 31.2±12.0S/CO, 6.1±2.4S/CO, 3.0±1.0S/CO and 3.9±1.3S/CO, respectively) compared to wild-type (306.8±64.1S/CO). Even more, Y100S and Y100S+S143L supernatants show no detectable-HBsAg (experiments in quadruplicate). In conclusions, unique HBsAg-mutations in genotype-D, different than those described in genotypes B/C (rarely found in western countries), tightly correlate with OBI, and strongly affect HBsAg-detection. By altering HBV-antigenicity and/or viral-particle maturation, they may affect full-reliability of universal diagnostic-assays for HBsAg-detection.

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OBJECTIVE: To investigate lamivudine (LAM)-resistance profiles of hepatitis B virus (HBV) at the early stages of virological breakthrough (serum HBV-DNA 12-345IU/ml) or when HBV-DNA is undetectable. METHODS: Sixty-four HBV-mono-infected patients were enrolled: 25 had virological breakthrough with serum HBV-DNA ranging from 12 to 345IU/ml during first-line LAM-monotherapy; 24 were on LAM-monotherapy, and 15 were on LAM+adefovir dipivoxil (ADV) with undetectable serum HBV-DNA (<12IU/ml). RESULTS: HBV-reverse transcriptase was successfully sequenced in 22 (88.0%) LAM-treated patients with HBV-DNA between 12 and 345IU/ml, and in 12 (30.8%) patients receiving LAM (±ADV) with HBV-DNA<12IU/ml. Drug-resistance mutations were observed in 17 (77.2%) LAM-treated patients with virological breakthrough: 8 M204V, 7 M204I, 1 M204I/V, and 1 A181T. One or ≥2 compensatory mutations were found in 10 (58.8%) and in 4 (23.5%) patients. Drug-resistance mutations were present also in patients with undetectable serum HBV-DNA: M204I was detected in 2 patients receiving LAM-monotherapy, and V84M in 1 patient receiving LAM+ADV. CONCLUSION: Overall findings support the existence of drug-resistance mutations even at very low levels of viral replication. The persistence of low-level HBV replication and consequent drug-resistance emergence should be considered when choosing therapeutic strategies.

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Occult hepatitis B virus infection (OBI) is characterized by the presence of ongoing viral replication with very low levels of viremia (<200 IU/ml), and negativity for HBsAg, while the so-called 'false' OBI with higher levels of HBV-DNA that are negative for HBsAg are usually due to the occurrence of mutations of the HBsAg sequence that may alter the recognition by some immunoassays. We describe here a case of occult HBV infection that combines both aspects. A male patient with severe systemic diseases, positive for anti-HBc and anti-HBs and negative for all other HBV markers, including HBsAg, since at least 4 years, showed a positivity for HBeAg at a follow-up control in November 2008; HBV-DNA testing by real-time PCR evidenced very low levels of viremia (<40 IU/ml), direct sequencing of the surface antigen-coding and Pol/RT coding regions allowed the identification of genotype D, serotype adw2, one immune escape mutation (G145R) and no drug resistance mutations. The positivity for HBeAg could be attributed to a superinfection in a naturally immune subject or to reactivation of a latent infection; the mutated virus had a reduced fitness and was therefore able to replicate only at low levels, resulting in a mild form of occult HBV infection.

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BACKGROUND: The Roche cobas TaqScreen test, an automated, multiplex nucleic acid test for blood screening for hepatitis B virus (HBV) DNA, hepatitis C virus (HCV) RNA, human immunodeficiency virus type 1 (HIV-1) groups M and O, and HIV-2 RNA, on the cobas s 201 platform, was evaluated by six European blood screening laboratories. STUDY DESIGN AND METHODS: The 95 percent limit of detection (LOD) of the cobas TaqScreen test for HBV, HCV, and HIV-1, using dilutions of the WHO International Standards, were evaluated. The clinical performance was determined by testing between 2000 to 6000 routine donor samples. Some laboratories evaluated the robustness, cross-contamination, and workflow. RESULTS: The mean 95 percent LOD (95% lower and upper confidence intervals) for HBV, HCV, and HIV-1 across all the laboratories were 3.8 (range, 3.0-5.2), 10.8 (range, 8.4-14.4), and 56.7 (range, 43.0-79.2) IU/mL, respectively. A total of 23,716 donors were tested in pools of 6. Fourteen initially reactive pools were detected, of which 6 contained a reactive donation, giving a positive predictive value of the pool results of 43 percent. One of the reactive donations was a HBV yield case (hepatitis B surface antigen-negative/anti-HBc-positive). Evaluation of the workflow for the system showed that an optimized batch loading in which a pipettor (Hamilton Microlab Star IVD) was utilized to half capacity was better than a full batch loading. CONCLUSION: The 95 percent LOD for the three viruses were comparable to those obtained by Roche. The test and platform were shown to be sensitive, specific, flexible, and robust.

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Cell membrane protein (CMP) profile of HIV-1 from cerebrospinal fluid (CSF) and plasma of five AIDS patients with neurologic disorders was analyzed and compared with viral quasispecies composition in these body compartments. To this aim, paired CSF and plasma samples from AIDS subjects with HIV-related neurological diseases (three HIV-1 encephalopaty (HIVE) and two primary CNS lymphoma (PCNSL)) underwent immobilized antibody capture (IAC) assay to determine the profile of CMP acquired by HIV-1. The considered CMPs were CD45RO, CD26, CD36, glut-R, N-CAM, VCAM-1, ELAM-1, CD44 and CD58, representing lymphomonocyte, neuronal and adhesion molecules. Cloning and sequencing of env and gag regions was performed to predict coreceptor usage and to analyze quasispecies compartmentalization. The results indicated that CD44 and CD58 were the most represented molecules on HIV-1 from CSF, whereas CD36 was the most abundant molecule on plasma HIV-1. V3 env aminoacidic sequences and net charge were consistent with M-R5 phenotype in all CSF and in most plasma clones. The degree of genetic heterogeneity (both complexity and diversity) in p17 gag was significantly lower in CSF-HIV than that in plasma-HIV for three patients, higher for one patient, and not significantly different for one patient, suggesting compartmentalization for all but the latter patient. When considering the pattern of CMP, the most abundant CMP observed in HIV from plasma and CSF was different in patients showing compartmentalization, while was the same in the patient without significant differences in CSF and plasma quasispecies. In conclusion, the present data on CMP pattern, V3 loop aminoacidic signature and genetic heterogeneity of HIV-1 quasispecies from CSF and plasma of HIVE patients, are consistent with a compartmentalized virus replication, at least in some patients, and with a possible different source of HIV in the two body sites, even though in a context of a largely prevalent M-R5 phenotype.

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Management of HCV infection and related liver disease with treatment currently available lead to a sustained virological response in 20% of patients using interferon (IFN)-alpha mono-therapy and approximately 40-45% in those on combination therapy with ribavirin.The aim of the present investigation was to compare the effect of consensus interferon alphacon-1 (C-IFN), and IFN-alpha 2b plus ribavirin, in patients relapsing after treatment with interferon alone. A total of 112 randomised patients with relapsing HCV infection (M/F=53/59), were treated for 24 weeks with: (A) IFN-alpha 2b starting with 5/6MU/day till negativity of HCV-RNA followed by 3MU every other day, plus ribavirin 15mg/kg/day (n=34); (B) C-IFN 9microg/day (n=40); (C) ursodeoxycholic acid (UDCA; sodium salt) 450mg/day (n=37). At the end of treatment, patients were observed at follow-up for 24 weeks.Clearance of HCV-RNA was achieved by the end of treatment in 23 patients (68%) in Group A and 21 also showed a biochemical response with normal ALT; in Group B, 33 patients (82%) had both a virological and a biochemical response; in Group C, one patient cleared HCV-RNA. At the end of follow-up (sustained-response), 29% of patients in Group A (n=10/34) had negative PCR (seven patients relapsed at the 4th week, six at the 12th); in Group B, a sustained response was achieved in 58% (p<0.03; two patients relapsed at the 4th week, three at the 12th and five at the 24th).MAJOR SIDE EFFECTS COMPRISED: neutropenia (n=17) and decrease in Hb>1.5g/dl (n=33) in Group A, recurrence of psoriasis in two patients in Group B and abdominal discomfort and diarrhoea in 11 patients in Group C.Rapid clearance of circulating HCV-RNA was induced by C-IFN (66% at three weeks, 71% at six weeks): this was a good prognostic index both for end of treatment and sustained response. Treatment with C-IFN lead to a higher response rate compared to that of recombinant IFN-alpha 2b in association with ribavirin. The action of C-IFN is superior in the time taken to reach the maximal response rate during treatment and in the lower prevalence of relapse of the infection.

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Background: Treatment of hepatitis C virus (HCV) infection with interferon (IFN) in older patients may not be feasible on account of side effects: we, therefore, attempted combined treatment with amantadine hydrochloride (AH) in order to improve not only the flu-like symptoms associated with IFN but also the anti-viral effect. Methods: Patients over 65 years of age, (n=165), who had failed to eradicate HCV infection after previous treatment with IFN were randomized into three groups and treated for 12 months, group A received AH 100 mg twice per day; group B received IFNalpha-n(3) 6 M units every other day for 3 months followed by 3 MU and group C the same dose of IFNalpha-n(3), as in B, and AH 200 mg per day. Results: Group A, 42 patients agreed to undergo treatment (genotype 1b n=39); at the end of treatment 21 patients (50%) had normal ALT and seven (17%) negative polymerase chain reaction (PCR). HCV-RNA was not detectable in seven patients at the sixth month follow-up and in six (14%) after 23plus minus2 months. Group B, 39 patients accepted the treatment (genotype 1b n=31); at the end of treatment, 17 patients (44%) had normal ALT and 13 negative PCR (13%). HCV-RNA was not detectable in nine patients (23%) at the sixth month of follow-up and in eight (21%) after 22plus minus4 months. Group C, 38 patients accepted the treatment (genotype 1b n=32); at the end of treatment, 20 (53%) patients had normal ALT and 15 negative PCR (39%). HCV-RNA was not detectable in 15 patients at the sixth month follow-up and in 11 after 21plus minus4 months (29%). Forty-six patients did not accept the scheme of treatment and 26 of them had a follow-up of 20plus minus3 months. HCV-RNA copies and prevalence of genotype 1b were comparable to the treated groups: HCV-RNA was fluctuating or unchanged during the entire follow-up. Conclusions: AH associated with IFN was able to improve the negativization of HCV-RNA and sustained response to IFN and decreased the malaise associated with IFN; an increase in viral copies was observed under AH in about 40%.