Management of Tacrolimus-Induced Toxicity With Normal Serum Levels After Liver Transplant.

Drug-induced liver injury after liver transplant occurs in 1.7% of patients. Tacrolimus is an effective immunosuppressant that is used to treat acute rejection. Although rare, it can cause toxicity, which is demonstrated by cholestatic liver injury. Here, we present a case of a young male patient who was diagnosed with Wilson disease, had penicillaminechelating therapy, and underwent living related liver transplant. Within 1 month posttransplant, he developed deranged, predominantly cholestatic pattern liver function tests. Laboratory parameters showed total bilirubin of 1.12 mg/ dL, alanine aminotransferase of 553 IU/L, gammaglutamyltransferase of 624 IU/L, and tacrolimus level of 10.2 ng/mL. After thorough evaluation, a liver biopsy was performed. Liver biopsy showed hepatocellular necrosis with centrilobular cholestasis without any evidence of graft rejection. However, with normal level of tacrolimus, the biopsy was suggestive of drug-induced liver injury. Thus, tacrolimus dose was reduced, resulting in improved liver function tests and patient discharge from the hospital. Tacrolimus is an effective immunosuppressant after liver transplant and has the ability to treat early acute rejection. The patient's liver biopsy showed hepatocellular necrosis with centrilobular cholestasis without any evidence of graft rejection. Cholestatic liver injury after tacrolimus usually resolves after dose reduction or by switching to another agent. With demonstrated tacrolimus-induced toxicity in liver transplant recipients, despite normal serum levels, transplant physicians should keep high index of suspicion regarding toxicity in the posttransplant setting.

Hydralazine-Induced Fulminant Liver Failure Requiring Urgent Liver Transplant: Common Drug With Rare Complication.

Drug-induced liver injury resulting in fulminant liver failure is a well-known condition, and many drugs have been documented in the literature as possible etiologies. However, hydralazine has seldom been reported as the offending agent. Our case report is about one such rare scenario of fulminant liver failure due to hydralazine use as an antihypertensive. A 65-year-old female patient presented with signs of fulminant liver failure 2 months after starting hydralazine for hypertension. She underwent extensive workup for the cause of acute liver failure. Other possible medications were ruled out, and workup for autoimmune and other etiologies were also negative. The patient underwent a deceased donor liver transplant and has been doing well since then. Her liver was found to be atrophic, with microscopically confirmed drug-induced liver injury. Hydralazine is used orally to treat essential hypertension and intravenously to emergently lower blood pressure. Hydralazineinduced acute liver failure is extremely rare. However, in this rare case where hydralazine-related drug-induced liver injury worsened to the extent of requiring liver transplant, we felt obliged to document and highlight this complication as a form of reminder to our colleagues of this serious outcome.

Liver Transplantation for Metamizole induced Acute Liver Failure.

Metamizole, or dipyrone, is a frequently prescribed analgetic drug that can cause drug-induced liver injury (DILI). Still, there are only a few metamizole-associated DILI cases (n = 61, including our study) described in the literature. So far liver transplantation has been reported in 6 patients with metamizole-induced acute liver failure. In 2020, a German group described a bigger cohort (n = 23) of metamizole-related DILI. Shortly thereafter, this issue gained wider attention as the German Federal Institute for Drugs and Medical Devices published a Direct Healthcare Professional Communication, emphasizing DILI as a potential adverse event caused by metamizole. We herein report 2 patients that were admitted to our liver transplant center due to acute liver failure (ALF) in April and May 2021. Both patients reported intake of metamizole as pain medication over a few weeks. After ruling out alternative reasons for ALF and fulfilling the King's College criteria both patients received emergency liver transplantations in our center. Pathology assessment of both explants were consistent with metamizole-associated DILI. As illustrated by our 2 cases of metamizole-induced liver failure with subsequent liver transplantation, this rare but presumably often overlooked adverse drug effect of metamizole should be considered as differential diagnosis in cases of cryptogenic liver failure.

Liver Transplantation for Acute Liver Injury in Asians Is More Likely Due to Herbal and Dietary Supplements.

Drug-induced liver injury (DILI) due to medications and herbal and dietary supplements (HDSs) is a major cause of acute liver injury leading to liver transplantation (LT). This study used United Network for Organ Sharing LT data to analyze severe HDS-induced acute liver injury in the United States. By convention, patients with acute DILI are listed as "Acute Hepatic Necrosis" (AHN) under the subheading "AHN: Drug Other Specify." All patients waitlisted from 1994 to 2020 were divided into 3 subgroups: "HDS DILI," "Non-HDS DILI," and "AHN: unknown drug." Analyses were performed to identify epidemiologic differences between patients with HDS DILI and non-HDS DILI. A subanalysis was performed for transplanted patients, including longitudinal changes. Of 1875 patients waitlisted for LT, 736 (39.2%) underwent LT. The proportion of Asian patients in the HDS DILI group was significantly higher compared with that in the non-HDS DILI group (17.4% versus 3.8%; P < 0.001). Excluding acetaminophen cases, the proportion of Black patients in the HDS DILI versus non-HDS group was significantly lower (8.7% versus 25.3%; P < 0.001). Waitlisted patients with HDS DILI were significantly older (median age, 38 years for HDS DILI versus 31 years for non-HDS DILI; P = 0.03). Lastly, the number of patients requiring LT due to HDS DILI increased significantly over time with more than 70% of cases occurring in the last 10 years (2010-2020) compared with the prior 15 years (1994-2009; Ptrend  = 0.001). Ethnicity may help in identifying the cause of severe acute DILI, a growing problem as more patients experiment with HDS.

Prognostic Value of the 13 C-Methacetin Breath Test in Adults with Acute Liver Failure and Non-acetaminophen Acute Liver Injury.

BACKGROUND AND AIMS: The 13 C-methacetin breath test (MBT) is a noninvasive, quantitative hepatic metabolic function test. The aim of this prospective, multicenter study was to determine the utility of initial and serial 13 C-MBT in predicting 21-day outcomes in adults with acute liver failure (ALF) and non-acetaminophen acute liver injury (ALI). APPROACH AND RESULTS: The 13 C-MBT BreathID device (Exalenz Biosciences, Ltd.) provided the percent dose recovery (PDR) for a duration of 60 minutes after administration of 13 C-methacetin solution as the change in exhaled 13 CO2 /12 CO2 compared with pre-ingestion ratio on study days 1, 2, 3, 5, and 7. Results were correlated with 21-day transplant-free survival and other prognostic indices. A total of 280 subjects were screened for enrollment between May 2016 and August 2019. Median age of the 62 enrolled patients with adequate data was 43 years, 79% were Caucasian, 76% had ALF with the remaining 24% having ALI. The mean PDR peak on day 1 or day 2 was significantly lower in nonsurvivors compared with transplant-free survivors (2.3%/hour vs. 9.1%/hour; P < 0.0001). In addition, serial PDR peaks were consistently lower in nonsurvivors versus survivors (P < 0.0001). The area under the receiver operating characteristic curve (AUROC) of the 13 C-MBT in the combined cohort was 0.88 (95% CI: 0.79-0.97) and higher than that provided by King's College (AUROC = 0.70) and Model for End-Stage Liver Disease scores (AUROC = 0.83). The 13 C-MBT was well tolerated with only two gastrointestinal adverse events reported. CONCLUSIONS: The 13 C-MBT is a promising tool to estimate the likelihood of hepatic recovery in patients with ALF and ALI. Use of the PDR peak data from the 13 C-MBT point-of-care test may assist with medical decision making and help avoid unnecessary transplantation in critically ill patients with ALF and ALI.

STAT6 up-regulation amplifies M2 macrophage anti-inflammatory capacity through mesenchymal stem cells.

Extensive infiltration of M2 macrophages plays a crucial role in repairing acute liver failure (ALF), however, the molecular pathways whereby mesenchymal stem cells (MSCs) induce M2 macrophage polarization remains unknown. We investigated the molecular pathways involved in MSC-induced M2 polarization and describe the potential therapeutic effects of M2 macrophages on ALF. The expression of M2 macrophage markers was significantly increased after M0 macrophages were co-cultured with MSCs in vitro. MSCs induced M2 macrophage polarization by activating STAT6, whereas a STAT6 inhibitor significantly inhibited the expression of M2 macrophage polarization markers (IL-4, CD163, TGF-ß, IL-10 and Arg-1). Finally, M2 macrophages significantly reduced the secretion of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) from injured hepatocytes. These results demonstrated that MSCs induced M2 macrophage polarization by activating STAT6, and that M2 macrophages increased the expression of anti-inflammatory factors to alleviate ALF.

Drug induced liver injury: from pathogenesis to liver transplantation.

Drug induced liver injury (DILI) is a necro-inflammatory liver disease caused by several drugs commonly used in clinical practice, herbs and dietary supplements prescribed for medical purposes. Despite its rarity, it represents the major cause of acute liver failure (ALF) requiring liver transplantation in USA and its frequency is increasing in Europe too. Two types of drug induced liver injury have been recognized: intrinsic and idiosyncratic. Predisposing factors may be classified in environmental, drugs- and individual- related risk factors, with the latter further distinguished in genetics and non-genetics. The liver injury can present with a hepatocellular, cholestatic or mixed pattern of disease. A definitive diagnosis of DILI is, nowadays, one of the main challenging issue in the management of these patients. Diagnosis often is based on suspicion derived from clinical history, biochemical exams and eventually on histological examination from liver biopsy. Score system may be helpful in these setting and new markers are gaining more prominence. Evaluation for liver transplantation is indicated when spontaneous resolution does not occur or in cases of ALF. Overall, the 1-year survival rate following liver transplantation is lower than that seen in patients who have been transplanted for chronic liver failure; however long-term survival is higher compared to other indications.

Therapeutic Potential of Bama Pig Adipose-Derived Mesenchymal Stem Cells for the Treatment of Carbon Tetrachloride-Induced Liver Fibrosis.

OBJECTIVES: Liver fibrosis is inevitable in the healing process of liver injury. Liver fibrosis will develop into liver cirrhosis unless the damaging factors are removed. This study investigated the potential therapy of Bama pig adipose-derived mesenchymal stem cells in a carbon tetrachloride-induced liver fibrosis Institute of Cancer Research strain mice model. MATERIALS AND METHODS: Adipose-derived mesenchymal stem cells were injected intravenously into the tails of mice of the Institute of Cancer Research strain that had been treated with carbon tetrachloride for 4 weeks. Survival rate, migration, and proliferation of adipose-derived mesenchymal stem cells in the liver were observed by histochemistry, fluorescent labeling, and serological detection. RESULTS: At 1, 2, and 3 weeks after adipose-derived mesenchymal stem cell injection, liver fibrosis was significantly ameliorated. The injected adipose-derived mesenchymal stem cells had hepatic differentiation potential in vivo, and the survival rate of adipose-derived mesenchymal stem cells declined over time. CONCLUSIONS: The findings in this study confirmed that adipose-derived mesenchymal stem cells derived from the Bama pig can be used in the treatment of liver fibrosis, and the grafted adipose-derived mesenchy-mal stem cells can migrate, survive, and differentiate into hepatic cells in vivo.

Liver Transplant Due to Flupirtine-Induced Acute Liver Failure.

OBJECTIVES: Acute drug-induced liver failure is a rare indication for liver transplant. There is only one case of flupirtine-induced liver failure requiring transplant in the literature. In February 2018, the European Medicines Agency issued a withdrawal of approval for flupirtine medication in European countries as a result of the risk of acute liver failure. MATERIALS AND METHODS: The aim of this study was a German-wide collection of data regarding patients with liver transplant as a result of flupirtine-associated liver failure. RESULTS: A total of 9 patients received transplants. All patients were women with a mean age of 43 years. Indication for flupirtine medication was musculoskeletal symptoms and migraine headache. The medication was taken over a period of approximately 3 months. All patients developed progressive acute liver failure, and no patient had previous chronic liver disease or cirrhosis. The mean laboratory Model for End Stage Liver Disease score for the patients was 31 ± 7 at time of transplant. Eight of the 9 patients were listed as "high urgency" for transplant. After transplant, they had an uneventful course with a prolonged mean intensive care unit stay of 13 ± 8.7 days. The whole hospitalization time was 43 ± 21 days. CONCLUSIONS: This is the largest published series of patients who received liver transplant after a drug-induced acute liver failure from flupirtine medication.

Coronavirus disease 2019 in an orthotopic liver transplant recipient living with human immunodeficiency virus.

Coronavirus disease 2019 (COVID-19), mediated by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), can manifest with flu-like illness and severe pneumonia with acute respiratory distress syndrome (ARDS). Immunocompromised patients merit particular attention as altered host immunity may influence both disease severity and duration of viral shedding as is described with several other ribonucleic acid respiratory viruses. Yet immunocompromised status alone, in the absence of other comorbidities, may not necessarily predict severe illness presentations and poorer clinical outcomes as indicated by recent reports of COVID-19-infected solid organ transplant recipients and people living with human immunodeficiency virus (HIV). Such patients may even be spared the robust inflammatory response that precipitates ARDS associated with COVID-19, complicating the management of iatrogenic immunosuppression in this setting. We present a case of an orthotopic liver transplant recipient with well-controlled HIV who successfully recovered from a mild, flu-like illness attributed to SARS-CoV-2.

Variants in ABCB4 (MDR3) across the spectrum of cholestatic liver diseases in adults.

The ATP binding cassette subfamily B member 4 (ABCB4) gene on chromosome 7 encodes the ABCB4 protein (alias multidrug resistance protein 3 [MDR3]), a P-glycoprotein in the canalicular membrane of the hepatocytes that acts as a translocator of phospholipids into bile. Several variants in ABCB4 have been shown to cause ABCB4 deficiency, accounting for a disease spectrum ranging from progressive familial cholestasis type 3 to less severe conditions like low phospholipid-associated cholelithiasis, intrahepatic cholestasis of pregnancy or drug-induced liver injury. Furthermore, whole genome sequencing has shown that ABCB4 variants are associated with an increased incidence of gallstone disease, gallbladder and bile duct carcinoma, liver cirrhosis or elevated liver function tests. Diagnosis of ABCB4 deficiency-related diseases is based on clinical presentation, serum biomarkers, imaging techniques, liver histology and genetic testing. Nevertheless, the clinical presentation can vary widely and clear genotype-phenotype correlations are currently lacking. Ursodeoxycholic acid is the most commonly used medical treatment, but its efficacy has yet to be proven in large controlled clinical studies. Future pharmacological options may include stimulation/restoration of residual function by chaperones (e.g. 4-phenyl butyric acid, curcumin) or induction of ABCB4 transcription by FXR (farnesoid X receptor) agonists or PPARα (peroxisome proliferator-activated receptor-α)-ligands/fibrates. Orthotopic liver transplantation remains the last and often only therapeutic option in cirrhotic patients with end-stage liver disease or patients with intractable pruritus.

Acute Liver Failure Caused by Use of Fat Burner: A Case Report.

Acute liver failure is a rare condition consisting of abrupt and extensive hepatocyte injury, leading to significant liver dysfunction associated with a high mortality. Liver transplantation is the most effective treatment in severe cases. The most common cause of acute liver failure in Western countries is drug-induced liver injury caused by prescription drugs and herbal and dietary supplements. Thermogenics, or fat burners, are a category of dietary supplements that claim to increase the resting metabolic rate, leading to weight loss. There are previous reports of acute liver failure associated with specific thermogenic formulations. We report the case of a 36-year-old male patient who developed jaundice 7 days after he started taking a thermogenic dietary supplement (Thermo Gun), with progressive deterioration of hepatic function and development of hepatic encephalopathy 19 days after the beginning of the symptoms. He had a Model for End-Stage Liver Disease score of 38 and fulfilled 4 of the King's College Criteria for poor prognosis in patients with acute liver failure. He underwent liver transplantation, receiving a graft from a cadaveric donor, and is alive with good liver graft function 2 years after the transplant. No possible causes for acute liver injury were identified other than the use of the supplement, which contained N-acetyl-L-tyrosine; 1,3,7-trimenthylxanthine; white willow; and 1-hydroxypholedrine. We found no previous reports in the literature of acute liver failure associated with those particular substances. This manuscript is compliant with the Helsinki Congress and the Istanbul Declaration.

Comparison of liver regeneration after partial hepatectomy and acetaminophen-induced acute liver failure: A global picture based on transcriptome analysis.

Liver regenerates following surgical removal and after drug-induced liver injury (DILI). However, most of the mechanisms of liver regeneration were identified using partial hepatectomy (PHX) model rather than using DILI models. We compared mechanisms of liver regeneration following PHX and after acetaminophen (APAP) overdose, a DILI model, using transcriptomic approach. Kinetics of hepatocyte proliferation and global gene expression profiles were studied in male C57BL/6J mice either subjected to PHX or following APAP overdose. Liver regeneration was much more synchronized after PHX as compared to APAP overdose. Transcriptomics analysis revealed activation of common upstream regulators in both models including growth factors HGF, EGF and VEGF; and cytokines IL6 and TNFα. However, magnitude of activation and temporality was significantly differed between the two models. HGF and VEGF showed similar activation between PHX and APAP but activation of EGF was significantly stronger in the APAP model. Activation of IL6 and TNFα transcriptional programs was delayed but remarkably higher in APAP. These dissimilarities could be attributed to inherent differences in the two models including significant injury and inflammation exclusively in the APAP model. This study highlights need to study mechanisms of liver regeneration after DILI separately from the mechanisms of regeneration PHX.

Successful liver transplantation for drug-induced vanishing bile duct syndrome.

Drug-induced cholestasis has a wide range of clinical presentations, and in a small number of patients, it can progress to severe ductopenia. A 63-year-old woman was referred to our department with progressive cholestasis and hyperbilirubinaemia following a course of flucloxacillin. Despite the comprehensive laboratory, imaging and genetic investigations, no other cause for the cholestasis was demonstrated. Sequential liver biopsies confirmed the development of vanishing bile duct syndrome. She developed significant cachexia and pruritus that did not respond to medical therapy, and hence she was listed for liver transplantation. She underwent liver transplantation 6 months after the initial drug-induced injury. She has remained well with good graft function at 1-year follow-up. The case highlights an extreme form of drug-induced ductopenia and underscores the need for meticulous hepatology input and consideration of liver transplantation in some patients.

Idiopathic copper toxicosis: is abnormal copper metabolism a primary cause of this disease?

Idiopathic copper toxicosis (ICT) is characterized by marked copper deposition, Mallory-Denk body (MDB) formation and severe hepatic injury. Although the characteristics are apparently different from Wilson disease, large amounts of copper accumulate in the liver of the patients. We extensively treated a patient with ICT to reduce the body copper, however, the patient needed liver transplantation. Previous liver biopsy revealed high copper content. But extirpated liver contained an extremely small amount of copper, although MDBs and severe inflammation remained. These phenomena suggest abnormal copper metabolism is not the principle cause of ICT but some other abnormality must exist.

Severe liver injury due to herbal and dietary supplements and the role of liver transplantation.

Herbal and dietary supplements (HDS) are increasingly used worldwide for numerous, mainly unproven health benefits. The HDS industry is poorly regulated compared to prescription medicines and most products are easily obtainable. Drug induced liver injury (DILI) is a well-recognized entity associated with prescription and over the counter medications and many reports have emerged of potential HDS-related DILI. There is considerable geographic variability in the risk and severity of DILI associated with HDS but the presentation of severe liver injury is similar with a hepatocellular pattern accompanied by jaundice. This type of injury can lead to acute liver failure and the need for liver transplantation. Patients will often fail to mention their use of HDS, considering it natural and therefore harmless. Hence physicians should understand that these products can be associated with DILI and explicitly ask about HDS use in any patient with otherwise unexplained acute liver injury.

Abdominal Compartment Syndrome After Liver Transplant in Drug-Induced Acute Liver Failure: A Case Report.

The incidence of drug-induced acute liver failure (ALF) has been increasing in recent years. Despite the complex intensive treatment, liver transplant should be performed in progressive cases. A systemic inflammatory response syndrome and the burden of surgical intervention promote abdominal compartment syndrome (ACS); observed preoperatively, they are significant negative prognostic factors. THE CASE: We demonstrate a young woman with liver transplant after ALF and a consecutive ACS. We presumed drug toxicity in the background of the rapidly progressive ALF, based on the preoperative hematologic examination and the histology of the removed liver. An ACS has occurred in the postoperative period that must have been resolved with mesh, and later, anatomic segment 2-3 resection had to be performed to further decrease the pressure. The patient left the hospital after 62 days with good graft function. DISCUSSION: A complex intensive care is mandatory in the case of orthotopic liver transplant for ALF. Outcomes are good after orthotopic liver transplant. An ACS might occur after surgery. In these rare cases a delayed abdominal closure or even a liver resection can be the only solution and sometimes an urgent need to resolve the life-threatening problem.

Potentials of Differentiated Human Cord Blood-Derived Unrestricted Somatic Stem Cells in Treatment of Liver Cirrhosis.

OBJECTIVES: Liver transplantation is the well-known treatment for chronic liver diseases; however, postoperative complications and lack of donors continue to be limitations with this treatment. Investigating new modalities for treatment of chronic liver illness is a must. In the present study, we aimed to clarify the effects of an in vitro hepatocyte-differentiated human unrestricted somatic stem cell transplant as a new cell-based therapy in an experimental model of chronic liver failure. MATERIALS AND METHODS: Human umbilical cord blood-derived unrestricted somatic stem cells were isolated, cultured, propagated, and characterized. Cells were directed to differentiate into hepatocyte-like cells. An animal model of carbon tetrachloride cirrhotic liver failure was prepared, and the human in vitro differentiated unrestricted somatic stem cells were transplanted into the experimental model. Animals that did not receive transplant served as the pathologic control group. Animals were euthanized 12 weeks after transplant, and liver functions and histopathology were assessed. RESULTS: Compared with the pathologic control group, the transplant group showed improvements in levels of alanine aminotransferase, aspartate aminotransferase, albumin, and bilirubin. Histopathologic examination of the transplant group also showed improvements in hydropic degeneration and fibrosis. CONCLUSIONS: The use of unrestricted somatic stem cells, isolated and propagated from cord blood and then differentiated into hepatocyte-like cells, improved both fibrosis and normal function of cirrhotic livers. These cells could be considered as a line of cell-based therapy in cases of chronic liver disease.

Effect of Stem Cell Treatment on Acute Liver Failure Model Using Scaffold.

BACKGROUND: Injecting MSCs via blood vessel is most commonly used method, which has a major drawback of safety. The aim of our study was to evaluate efficacy using scaffold-loaded MSCs in acute liver failure model. METHOD: Acute liver failure was induced in mice using thioacetamide (TAA) (200 mg/kg, i.p) once a day for two consecutive days. The animals were divided in four acute liver failure groups: (1) TAA; (2) empty scaffold; (3) MSCs injected through tail vein; (4) MSC + Scaffold, scaffold loaded with MSCs, to evaluate the mortality and changes in liver function. Polylactic-co-glycolic acid scaffold alone and loaded with human MSCs was implanted on mice dorsum. RESULTS: TAA dose was titrated until one-third mortality rate was achieved. TAA (200 mg/kg) once daily for two consecutive days was injected to establish the acute liver failure model. The mortality of TAA and scaffold groups was 55.9% and 63.2%, respectively. Although, mortality of MSC-TV group decreased 14.7% as compared to TAA group (p = 0.200), MSC + Scaffold group had the lowest mortality (31.4%) (p = 0.013). Cells implanted in PLGA biomaterial were survived until 3 weeks, and their function was increased. Area of hepatic inflammation and necrosis was significantly reduced in MSC-TV and MSC + Scaffold groups; but there was no difference between the two groups. Gene expressions related to inflammation were significantly decreased in MSC-TV and MSC + Scaffold groups compared to TAA group. In MSC + Scaffold group, no migration of stem cells to liver tissue was observed. Although, not all cells in scaffold were stained, some of them were differentiated into hepatocyte-like cells which stained positive for PAS and CYP2E1 antibody. CONCLUSION: Scaffold loaded with MSCs showed protective effects via paracrine signaling on acute liver failure model.

Enhanced Regeneration and Hepatoprotective Effects of Interleukin 22 Fusion Protein on a Predamaged Liver Undergoing Partial Hepatectomy.

Liver ischemia-reperfusion injury (IRI) and regeneration deficiency are two major challenges for surgery patients with chronic liver disease. As a survival factor for hepatocytes, interleukin 22 (IL-22) plays an important role in hepatoprotection and the promotion of regeneration after hepatectomy. In this study, we aim to investigate the roles of an interleukin 22 fusion protein (IL-22-FP) in mice with a predamaged liver after a two-third partial hepatectomy (PHx). Predamaged livers in mice were induced by concanavalin A (ConA)/carbon tetrachloride (CCl4) following PHx with or without IL-22-FP treatment. A hepatic IRI mouse model was also used to determine the hepatoprotective effects of IL-22-FP. In the ConA/CCl4 model, IL-22-FP treatment alleviated liver injury and accelerated hepatocyte proliferation. Administration of IL-22-FP activated the hepatic signal transducer and activator of transcription 3 (STAT3) and upregulated the expression of many mitogenic proteins. IL-22-FP treatment prior to IRI effectively reduced liver damage through decreased aminotransferase and improved liver histology. In conclusion, IL-22-FP promotes liver regeneration in mice with predamaged livers following PHx and alleviates IRI-induced liver injury. Our study suggests that IL-22-FP may represent a promising therapeutic drug against regeneration deficiency and liver IRI in patients who have undergone PHx.