Review of the eligible studies == Data extracted from your selected articles are reported in detail in Table1. (95% CI = 0.220.61;P< .001). HBIG + NUC combined treatment reduced HBV reappearance respect to NUC alone (OR = 0.22; 95% CI = 0.160.30;P< .0001). Similarly, HBIG alone was significantly better than NUC alone in preventing HBV recurrence (OR = 0.20; 95% CI = 0.090.44;P< .0001). == Conclusions == Prophylaxis with HBIG is relevant in preventing postLT HBV recurrence. Its combination with NUC gives the best results in terms of protection. The present results should be considered in light of the fact that also aged studies based on lamivudine use were included. Studies exploring in detail high genetic barriertorecurrence NUC and protocols with definite use of HBIG are needed. Keywords:adefovir, entecavir, lamivudine, liver transplantation, nucleos(t)ide analogues, prophylaxis == 1. INTRODUCTION == Hepatitis B computer virus (HBV) represents a major global health problem worldwide.1According to the World Health Organization estimations, approximately 300 million people have been infected Preladenant with chronic HBV, with twothirds being in Asia.2HBVrelated endstage liver disease (ie acute liver failure and cirrhosis) and its complication hepatocellular carcinoma are among the principal indications for liver transplantation (LT).3However, transplanted patients without any prophylaxis may suffer from HBV recurrence in up to 80% of cases.4Hepatitis B immunoglobulin (HBIG) represents an efficient passive immune agent against HBV, and longterm passive immunoprophylaxis after LT results in a 60%80% reduction of HBV recurrence.5Unfortunately, longterm HBIG usage presents some drawbacks, such as relevant costs and the need to repeatedly monitor hepatitis B surface antibody levels.6 In the clinical practice, following the introduction of the nucleoside analogue lamivudine (LAM) combined with HBIG, a further reduction of the HBV recurrence rates has been reported.7However, LAM has a low genetic barriertoresistance.8Currently, more potent drugs with a high genetic barriertoresistancesuch as the nucleos(t)ide analogues (NUC) adefovir (ADV), entecavir (ETV) and tenofovir (TDF)have been introduced to avoid the risk of viral recurrence in transplanted patients.9,10 Due to their potent effect, the exclusive prophylactic Preladenant use of high genetic barriertoresistance NUC without HBIG has been proposed to avoid the problems associated with longterm immunoprophylaxis.11With the intent to gain a better insight into this issue, a metaanalysis has SELP been performed to evaluate the practical necessity of HBIG in the prophylaxis of postLT HBV recurrence. To this end and to explore all the potential clinical settings, the HBV recurrence rates after LT were compared in patients receiving prophylaxis based on (a) HBIG alone vs HBIG+NUC; (b) HBIG alone vs NUC alone; and (c) HBIG+NUC vs NUC alone. We further performed some subanalyses to investigate the role of low and high genetic barriertoresistance NUC. == 2. MATERIALS AND METHODS == == 2.1. Search sources and study design == A systematic review of the published literature focused on the role of HBIG in the prophylaxis of HBV recurrence after LT was undertaken. The search strategy was performed following the Preferred Reporting Items for Systemic Reviews and MetaAnalysis (PRISMA) guidelines.12 The specific research question formulated in the present study includes the following Patients, Intervention, Comparator, Outcome (PICO) components: Patient: patient with endstage acute or chronic HBVrelated liver disease undergoing LT; Intervention: prophylaxis based on HBIG (NUC); Comparison: prophylaxis based on NUC only; Result: HBV recurrence after LT, thought as the detectability of HBsAg or HBV DNA through the scholarly research period. A search from the PubMed and Cochrane Central Register of Managed Trials Directories was carried out using the next conditions: (HBV) AND (liver organ transplant*) AND (recurrence). The search period was from 2000/01/01 to 2020/11/09. The organized qualitative examine included only British research that included human being patients. Published reviews were excluded predicated on many requirements: (a) data on pet versions; (b) lacked plenty of medical information; and (c) got nonprimary resource data (eg review content articles, nonclinical studies, characters towards the editor, professional opinions and meeting summaries). In the entire case of research from the same center, the feasible overlapping of medical instances was examined, as well as the most educational research was regarded as eligible. == 2.2. Data removal and meanings == Carrying out a fulltext overview of the qualified studies, two 3rd party writers (QL and EGG) performed the info removal and crosschecked all results. During selecting content articles and extracting the info, potential discrepancies had been resolved carrying out a consensus having a third reviewer (GM). Collected data included the 1st writer of the publication, season of publication, Preladenant nation and the real amount of treated and recurred instances based on the different treatments adopted. == 2.3. Quality evaluation ==.