Immune-escape mutations and stop-codons in HBsAg develop in a large proportion of patients with chronic HBV infection exposed to anti-HBV drugs in Europe

Background: HBsAg immune-escape mutations can favor HBV-transmission also in vaccinated individuals, promote immunosuppression-driven HBV-reactivation, and increase fitness of drug-resistant strains. Stop-codons can enhance HBV oncogenic-properties. Furthermore, as a consequence of the overlapping structure of HBV genome, some immune-escape mutations or stop-codons in HBsAg can derive from drug-resistance mutations in RT. This study is aimed at gaining insight in prevalence and characteristics of immune-associated escape mutations, and stop-codons in HBsAg in chronically HBV-infected patients experiencing nucleos(t)ide analogues (NA) in Europe. Methods: This study analyzed 828 chronically HBV-infected European patients exposed to ≥ 1 NA, with detectable HBV-DNA and with an available HBsAg-sequence. The immune-associated escape mutations and the NA-induced immune-escape mutations sI195M, sI196S, and sE164D (resulting from drug-resistance mutation rtM204 V, rtM204I, and rtV173L) were retrieved from literature and examined. Mutations were defined as an aminoacid substitution with respect to a genotype A or D reference sequence. Results: At least one immune-associated escape mutation was detected in 22.1% of patients with rising temporal-trend. By multivariable-analysis, genotype-D correlated with higher selection of ≥ 1 immune-associated escape mutation (OR[95%CI]:2.20[1.32-3.67], P = 0.002). In genotype-D, the presence of ≥ 1 immune-associated escape mutations was significantly higher in drug-exposed patients with drug-resistant strains than with wild-type virus (29.5% vs 20.3% P = 0.012). Result confirmed by ana

Cytomegalovirus infection management in solid organ transplant recipients across European centers in the time of molecular diagnostics: An ESGICH survey

Background: Scant information is available about how transplant centers are managing their use of quantitative molecular testing (QNAT) assays for active cytomegalovirus (CMV) infection monitoring in solid organ transplant (SOT) recipients. The current study was aimed at gathering information on current practices in the management of CMV infection across European centers in the era of molecular testing assays. Methods: A questionnaire-based cross-sectional survey study was conducted by the European Study Group of Infections in Immunocompromised Hosts (ESGICH) of the Society of Clinical Microbiology and Infectious Diseases (ESCMID). The invitation and a weekly reminder with a personal link to an Internet service provider (https://es.surveymonkey.com/) was sent to transplant physicians, transplant infectious diseases specialists, and clinical virologists working at 340 European transplant centers. Results: Of the 1181 specialists surveyed, a total of 173 responded (14.8%): 73 transplant physicians, 57 transplant infectious diseases specialists, and 43 virologists from 173 institutions located at 23 different countries. The majority of centers used QNAT assays for active CMV infection monitoring. Most centers preferred commercially available real-time polymerase chain reaction (RT-PCR) assays over laboratory-developed procedures for quantifying CMV DNA load in whole blood or plasma. Use of a wide variety of DNA extraction platforms and RT-PCR assays was reported. All programs used antiviral prophylaxis, preemptive therapy, or both, according to current guidelines. However, the centers used different criteria for starting preemptive antiviral treatment, for monitoring systemic CMV DNA load, and for requesting genotypic assays to detect emerging CMV-resistant variants. Conclusions: Significant variation in CMV infection management in SOT recipients still remains across European centers in the era of molecular testing. International multicenter studies are required to achieve commutability of CMV testing and antiviral management procedures