MELD-35 rule was introduced in the USA in 2013 to allow regional sharing of organs, to reduce the high mortality rates of patients with MELD ≥ 35. Although this change has reduced mortality for patients with high MELD-Na scores, by enabling regional sharing, its impact on patients with ACLF-3 is unknown. Our aims were to determine whether share MELD-35 addresses the high mortality on the waiting list of patients with acute on chronic liver failure grade 3 (ACLF-3). Method: We studied the UNOS database, years 2010–2017. ACLF was identified using the EASL-CLIF definition. We assessed the effect of the share 35 rule according to year of LT, specifically years 2010–2012 considered pre-share 35 and years 2014–2016 designated post-share 35. We evaluated outcomes of 90-day waitlist mortality using competing risks regression analysis. Results: We identified 6,342 candidates at listing with a MELD-Na score > = 35, of which 3,122 patients had ACLF-3. Among those with ACLF-3, extra-hepatic organ failures were significantly more preva- lent in patients with 4–6 organ failures. Competing risks regression, adjusting for age, etiology of liver disease, and MELD-Na score, revealed that candidates listed with ACLF-3 had a significant risk for 90-day waitlist mortality (SHR = 1.76; 95% CI 1.27–2.44), particularly those with four or more organ failures (SHR = 3.01; 95% CI 2.15–4.24). (Figure) ACLF-1 and ACLF-2 were not associated with greater mortality relative to no ACLF. Organ failures with the strongest association for waitlist mortality included mechanical ventilation (SHR = 1.89; 95% CI 1.67–2.15), circulatory failure (SHR= 1.64; 95% CI 1.45–1.86) and brain failure (SHR = 1.16; 95% CI 1.03–1.33). LT occurring post-share 35 was associated with reduced 90-day waitlist mortality among patients listed with ACLF-3 and MELD-Na score ≥ 35 (SHR = 0.58; 95% CI 0.49–0.69). However, among patients with 4–6 organ failures, LT after share 35 implementation was not significantly associated with reduced waitlist mortality (SHR = 0.79; 95% CI 0.60– 1.05). Conclusion: Although regional sharing of organs for patients with MELD ≥ 35 is associated with a significant reduction in waitlist mortality, patients with ACLF-3, particularly those with extra-hepatic organ failures are not fullyaddressed by this scheme. Incorporation of ACLF grading into organ allocation schemes may allow more equitable distribution of organs. AS009 Pretransplant rifaximin administration reduces posttransplant liver injury and early allograft dysfunction in mouse and human liver transplantation Takahiro Ito 1 , Shoichi Kageyama 1 , Kojiro Nakamura 1,2,3 , Hirofumi Hirao 1 , Kentaro Kadono 1 , Hidenobu Kojima 1 , Ronald Busuttil 1 , Fady M. Kaldas 1 , Jerzy Kupiec-Weglinski 1 . 1 The Dumont-UCLATransplant Center, Department of Surgery, Los Angeles, United States; 2 Kyoto University, Department of Surgery, Kyoto, Japan; 3 Nishi-Kobe Medical Center, Department of Surgery Email: jkupiec@mednet.ucla.edu Background and Aims: Rifaximin commonly used to treat hepatic encephalopathy is a minimally absorbed antibiotic. Gut-liver axis is considered to play an important role in hepatic injury, and its microbiota is receiving increased attention in the field of organ transplantation. We examined the effectiveness of rifaximin treat- ment in mice and human liver transplant (LT) recipients on hepatocellular graft injury. Methods: In the experimental arm, livers from C57BL/6 mice were transplanted to allogeneic BALB/c mice after 18 h of cold-storage. To examine the impact of gut microbiota, fecal microbiota transplant (FMT) was performed prior to LT in three major groups (n = 4/grp): Gr. I - control (naïve untreated); Gr. II - rifaximin (7d rifaximin treatment prior to LT); Gr. III - rifaximin + FMT (7d rifaximin treatment + FMT from naïve mice). In the clinical arm, 447 adult primary LT recipients were retrospectively reviewed and classified based on the duration of pre-LTrifaximin therapy: Gr. I - rifaximin ( ≥ 7d); and Gr. II - control (<7d). Results: In mouse LT recipients, rifaximin treatment prevented hepatocellular damage, evidenced by lower serum transaminase levels as compared to control or rifaximin+ FMT groups (control vs rifaximin vs rifaximin + FMT vs control, mean ALT (IU/L): 8132 vs 3197 vs 8897, resp., p< 0.05). In addition, LT in rifaximin group showed significantly lower Suzuki’s histological score of hepatocellular injury; and lower CD68 (macrophage)/Ly6G (neutrophil) infiltration as compared to control or rifaximin + FMT group (p < 0.05). In the clinical arm, 260 LT patients who underwent ≥7d rifaximin treatment were characterized by significantly lower maximum postoperative serum ALT levels within 7 POD (409 vs 571 IU/L, p < 0.001) and depressed occurrence of early allograft dysfunction (EAD; 22.7 vs 31.0%, p =0.048) as compared with controls. Notably, multivariate analysis identified pre-LT rifaximin treatment of <7d as an independ- ent risk factors for development of EAD (Odds ratio: 1.917, p = 0.008), along extended cold ischemia time ( p = 0.003), higher donor age ( p = 0.003), and larger amount of blood transfusions (p = 0.019). Conclusion: We demonstrated the effectiveness of rifaximin therapy prior to LT in mice and humans, assessed by graft hepatocellular damage and EAD. As rifaximin-mediated benefits were negated by concomitant FMT from normal mice, targeting gut microbiota has a therapeutic potential to prevent post-LT injuryand improve clinical outcomes. AS010 Reassessment of the risk of recurrence (R3) after liver transplantation for HCC: validation of the R3 v.2 score and comparison with existing models: results of a multinational analysis in 2,444 patients Charlotte Costentin 1 , Federico Pinero 2 , Helena Degroote 3 , Andrea Notarpaolo 4 , Ilka Boin 5 , Karim Boudjema 6 , Cinzia Baccaro 7 , Luis G. Podestá 2 , Philippe Bachellier 8 , Giuseppe Maria Ettorre 9 , Jaime Poniachik 10 , Fabrice Muscari 11 , Fabrizio Di Benedetto 12 , Sergio Hoyos Duque 13 , Ephrem Salamé 14 , Umberto Cillo 15 , Adrian Gadano 16 , Claire Vanlemmens 17 , Stefano Fagiuoli 18 , Fernando Rubinstein 19 , Patrizia Burra 20 , Hans Van Vlierberghe 3 , Marcelo Silva 2 , Christophe Duvoux 21 . 1 Gastroenterology, Hepatology and Transplant Unit, CHU Grenoble-Alpes, Grenoble, France; 2 Hospital Universitario Austral, School of Medicine, Argentina and Latin American ORAL PRESENTATIONS S9 Journal of Hepatology 2020 vol. 73 | S1–S18