M. Paoloni

Hepatitis B surface antigen genetic elements critical for immune escape correlate with hepatitis B virus reactivation upon immunosuppression

Hepatitis B virus (HBV) reactivation during immunosuppression can lead to severe acute hepatitis, fulminant liver failure, and death. Here, we investigated hepatitis B surface antigen (HBsAg) genetic features underlying this phenomenon by analyzing 93 patients: 29 developing HBV reactivation and 64 consecutive patients with chronic HBV infection (as control). HBsAg genetic diversity was analyzed by population‐based and ultradeep sequencing (UDS). Before HBV reactivation, 51.7% of patients were isolated hepatitis B core antibody (anti‐HBc) positive, 31.0% inactive carriers, 6.9% anti‐HBc/anti‐HBs (hepatitis B surface antibody) positive, 6.9% isolated anti‐HBs positive, and 3.4% had an overt HBV infection. Of HBV‐reactivated patients, 51.7% were treated with rituximab, 34.5% with different chemotherapeutics, and 13.8% with corticosteroids only for inflammatory diseases. In total, 75.9% of HBV‐reactivated patients (vs. 3.1% of control patients; P < 0.001) carried HBsAg mutations localized in immune‐active HBsAg regions. Of the 13 HBsAg mutations found in these patients, 8 of 13 (M103I‐L109I‐T118K‐P120A‐Y134H‐S143L‐D144E‐S171F) reside in a major hydrophilic loop (target of neutralizing antibodies [Abs]); some of them are already known to hamper HBsAg recognition by humoral response. The remaining five (C48G‐V96A‐L175S‐G185E‐V190A) are localized in class I/II–restricted T‐cell epitopes, suggesting a role in HBV escape from T‐cell‐mediated responses. By UDS, these mutations occurred in HBV‐reactivated patients with a median intrapatient prevalence of 73.3% (range, 27.6%‐100%) supporting their fixation in the viral population as a predominant species. In control patients carrying such mutations, their median intrapatient prevalence was 4.6% (range, 2.5%‐11.3%; P < 0.001). Finally, additional N‐linked glycosylation (NLG) sites within the major hydrophilic loop were found in 24.1% of HBV‐reactivated patients (vs. 0% of chronic patients; P < 0.001); 5 of 7 patients carrying these sites remained HBsAg negative despite HBV reactivation. NLG can mask immunogenic epitopes, abrogating HBsAg recognition by Abs. Conclusion: HBV reactivation occurs in a wide variety of clinical settings requiring immune‐suppressive therapy, and correlates with HBsAg mutations endowed with enhanced capability to evade immune response. This highlights the need for careful patient monitoring in all immunosuppressive settings at reactivation risk and of establishing a prompt therapy to prevent HBV‐related clinical complications. (Hepatology 2015;61:823–833)

Multiclass HCV resistance to direct-acting antiviral failure in real-life patients advocates for tailored second-line therapies

Despite the excellent efficacy of direct‐acting antivirals (DAA) reported in clinical trials, virological failures can occur, often associated with the development of resistance‐associated substitutions (RASs). This study aimed to characterize the presence of clinically relevant RASs to all classes in real‐life DAA failures.

A recent epidemiological cluster of acute hepatitis B genotype F1b infection in a restricted geographical area of Italy

In this study, by phylogenetic analysis, we identified an epidemiological cluster involving eight individuals diagnosed with acute hepatitis B virus (HBV) infection related to unprotected sexual intercourse in a restricted area of central Italy (time period: 2011-2014). Notably, these patients (six of eight Italians) were infected by subgenotype F1b, which is not commonly found in western countries. Ultra-deep pyrosequencing confirmed a superimposable composition of HBV quasi-species in these patients. Despite the availability of effective vaccination, this study highlights the importance of not underestimating the risk of HBV infection, of continuing to set up surveillance programmes for HBV infection, and of investigating the pathogenetic potential of these atypical genotypes.

Frequent NS5A and multiclass resistance in almost all HCV genotypes at DAA failures: what are the chances for second-line regimens?

Velia Chiara Di Maio, Valeria Cento, Marianna Aragri, Stefania Paolucci, Teresa Pollicino, Nicola Coppola, Bianca Bruzzone, Valeria Ghisetti, Maurizio Zazzi, Maurizia Brunetto, Ada Bertoli, Silvia Barbaliscia, Silvia Galli, William Gennari, Fausto Baldanti, Giovanni Raimondo, Carlo Federico Perno, Francesca Ceccherini-Silberstein, on behalf of treatment team of the HCV Virology Italian Resistance Network (VIRONET-C),

P681 HBsAg MUTATIONS WITH ENHANCED CAPABILITY TO EVADE IMMUNE RESPONSE ARE ASSOCIATED WITH HBV REACTIVATION DURING IMMUNOSUPPRESSION

P681 HBsAg MUTATIONS WITH ENHANCED CAPABILITY TO EVADE IMMUNE RESPONSE ARE ASSOCIATED WITH HBV REACTIVATION DURING IMMUNOSUPPRESSION R. Salpini, C. Alteri, L. Colagrossi, M.-C. Bellocchi, D. Armenia, F. Di Santo, L. Carioti, F. Continenza, A. Bertoli, Y. Louzoun, M. Pollicita, A. Ricciardi, C. Mastroianni, M. Paoloni, A. Marrone, L. Sarmati, C. Sarrecchia, M. Andreoni, M. Angelico, C.-F. Perno, V. Svicher. University of Rome Tor Vergata, I.N.M.I. L. Spallanzani, Rome, Italy; Bar-Ilan University, Ramat Gan, Israel; Sapienza University of Rome, Rome, S.S. Filippo e Nicola Hospital, Avezzano, Second University of Naples, Naples, Tor Vergata University Hospital, Rome, Italy E-mail: valentina.svicher@uniroma2.it