Towards tolerance in liver transplantation

Life-long immunosuppression has always been considered the key in managing liver graft protection from recipient rejection. However, it is associated with severe adverse effects that lead to increased morbidity and mortality, including infections, cardiovascular diseases, kidney failure, metabolic disorders and de novo malignancies. This explains the great interest that has developed in the concept of tolerance in recent years. The liver, thanks to its marked tolerogenicity, is to be considered a privileged organ: up to 60% of selected patients undergoing liver transplantation could safely withdraw immunosuppression.

Circadian Rhythm and Melatonin in Liver Carcinogenesis: Updates on Current Findings

Liver cancer, including hepatocellular carcinoma and cholangiocarcinoma, can be devastating if not treated early. The risk factors of liver cancer include alcoholic liver disease, non-alcoholic fatty liver disease, disruption of melatonin levels, and dysregulated circadian rhythm. The circadian rhythm is a 24-hour biological clock that regulates the physiological activities at both central and peripheral levels. Its molecular mechanism exists in every cell in mammals. Disruption of the circadian rhythm has found in liver cancers as an independent risk factor. This review summarized the most recent findings about the molecular mechanisms of circadian rhythm, the crosstalk between core clock genes and melatonin, as well as the role of circadian rhythm and melatonin played in chronic liver diseases and liver cancer. Finally, we discussed the potential clinical application of circadian rhythm and melatonin for the treatment of liver cancer and discussed future perspectives of how understanding the circadian rhythm in liver cancer progression could provide new clinical applications for liver cancer treatment and diagnosis.

Clinical Operational Tolerance and Immunosuppression Minimization in Kidney Transplantation: Where Do We Stand?

BACKGROUND

The 20th century represents a breakthrough in the transplantation era, since the first kidney transplantation between identical twins was performed. This was the first case of tolerance, since the recipient did not need immunosuppression. However, as transplantation became possible, an immunosuppression-free status became the ultimate goal, since the first tolerance case was a clear exception from the hard reality nowadays represented by rejection.

METHODS

A plethora of studies was described over the past decades to understand the molecular mechanisms responsible for rejection. This review focuses on the most relevant studies found in the literature where renal tolerance cases are claimed. Contrasting, and at the same time, encouraging outcomes are herein discussed and a glimpse on the main renal biomarkers analyzed in this field is provided.

RESULTS

The activation of the immune system has been shown to play a central role in organ failure, but also it seems to induce a tolerance status when an allograft is performed, despite tolerance is still rare to register. Although there are still overwhelming challenges to overcome and various immune pathways remain arcane; the immunosuppression minimization might be more attainable than previously believed.

CONCLUSION

. Multiple biomarkers and tolerance mechanisms suspected to be involved in renal transplantation have been investigated to understand their real role, with still no clear answers on the topic. Thus, the actual knowledge provided necessarily leads to more in-depth investigations, although many questions in the past have been answered, there are still many issues on renal tolerance that need to be addressed.

Pitfalls in the reporting of upper endoscopy features in cirrhotic patients

BACKGROUND

Upper endoscopy is the main tool for the accurate assessment of the risk of bleeding in cirrhotic patients.

AIM

To evaluate the diagnostic accuracy of upper endoscopy, in cirrhotic subjects, during common clinical practice.

METHODS

120 endoscopic reports produced in different hospitals in our region were retrospectively and randomly selected. After a general evaluation, aimed at assessing the description of various endoscopic features, reports were evaluated by four expert endoscopists and four expert hepatologists. Experts were asked to fill in a questionnaire for each single endoscopic procedure, regarding the diagnostic accuracy of the report.

RESULTS

Endoscopic reports lacked descriptions of the size of esophageal varices and red signs in 14% and 29% of cases respectively. Presence (or absence) of gastric varices or portal hypertensive gastropathy were not reported in 62% and 34% of cases respectively. According to expert endoscopists 41% of the reports were incomplete, while, according to hepatologists, reports were incomplete and inadequate for clinical purposes in 36% of cases.

CONCLUSION

Our study clearly evidenced a significant lack of information in reports on upper endoscopy in cirrhotic patients, and supports the prompt adoption of corrective strategies.

Secondary bile acids and the biliary epithelia: The good and the bad

The biliary tract has been considered for several decades a passive system just leading the hepatic bile to the intestine. Nowadays several researches demonstrated an important role of biliary epithelia (i.e. cholangiocytes) in bile formation. The study of biliary processes therefore maintains a continuous interest since the possible important implications regarding chronic cholestatic human diseases, such as primary biliary cholangitis or primary sclerosing cholangitis. Bile acids (BAs), produced by the liver, are the most represented organic molecules in bile. The physiologic importance of BAs was initially attributed to their behavior as natural detergents but several studies now demonstrate they are also important signaling molecules. In this minireview the effect of BAs on the biliary epithelia are reported focusing in particular on secondary (deriving by bacterial manipulation of primary molecules) ones. This class of BAs is demonstrated to have relevant biological effects, ranging from toxic to therapeutic ones. In this family ursodeoxycholic and lithocholic acid present the most interesting features. The molecular mechanisms linking ursodeoxycholic acid to its beneficial effects on the biliary tract are discussed in details as well as data on the processes leading to lithocholic damage. These findings suggest that expansion of research in the field of BAs/cholangiocytes interaction may increase our understanding of cholestatic diseases and should be helpful in designing more effective therapies for biliary disorders.

Gallstone and Gallbladder Disease: Biliary Tract and Cholangiopathies

Cholestatic liver diseases are named primarily due to the blockage of bile flow and buildup of bile acids in the liver. Cholestasis can occur in cholangiopathies, fatty liver diseases, and during COVID-19 infection. Most literature evaluates damage occurring to the intrahepatic biliary tree during cholestasis; however, there may be associations between liver damage and gallbladder damage. Gallbladder damage can manifest as acute or chronic inflammation, perforation, polyps, cancer, and most commonly gallstones. Considering the gallbladder is an extension of the intrahepatic biliary network, and both tissues are lined by biliary epithelial cells that share common mechanisms and properties, it is worth further evaluation to understand the association between bile duct and gallbladder damage. In this comprehensive article, we discuss background information of the biliary tree and gallbladder, from function, damage, and therapeutic approaches. We then discuss published findings that identify gallbladder disorders in various liver diseases. Lastly, we provide the clinical aspect of gallbladder disorders in liver diseases and ways to enhance diagnostic and therapeutic approaches for congruent diagnosis. © 2023 American Physiological Society. Compr Physiol 13:4909-4943, 2023.

The Effects of Sustained Immunosuppression Withdrawal After Liver Transplantation on Metabolic Syndrome

BACKGROUND

Liver transplant (LT) recipients often experience adverse effects of immunosuppressive (IS) drugs, especially on metabolic profiles. Selected LT recipients can achieve successful IS withdrawal; however, its effects on metabolic syndrome (MS) are unknown.

METHODS

This is a retrospective single-center study investigating the incidence and/or regression of MS in 75 selected LT recipients who were previously enrolled in prospective IS withdrawal trials between 1999 and 2017. Patients who were transplanted due to nonalcoholic steatohepatitis/metabolic-associated fatty liver disease were excluded, as well as those with a follow-up <3 y after IS weaning.

RESULTS

Forty-four patients (58.7%) achieved sustained withdrawal or minimization of immunosuppression (WMIS) and 31 patients (41.3%) required reintroduction of immunosuppression (no-WMIS). Among LT recipients who were metabolically healthy (n = 52, 69.3%) before the start of IS weaning, there was a significantly lower rate of de novo MS in WMIS patients compared with no-WMIS patients after 5 y (8.3% and 47.8%, respectively, P  = 0.034). Of 23 LT recipients (30.7%) who had MS at the time of commencing IS withdrawal, complete regression of MS was observed in 47.1% of WMIS patients and in none (0%) of the no-WMIS patients after 5 y ( P  = 0.054). Furthermore, individual components of MS were better controlled in IS-weaned patients, such as arterial hypertension and abnormal serum lipids.

CONCLUSIONS

Achievement of sustained IS withdrawal reduces the incidence of de novo MS development in metabolically healthy patients and increases the likelihood of MS regression in patients with established MS. The foreseeable long-term beneficial effects of these favorable metabolic changes on morbidity and mortality of LT recipients require further investigation.

Safety and efficacy of simultaneous liver transplantation and sleeve gastrectomy in morbid obese patients with end-stage liver disease: The LT-SG study

In obese patients, metabolic dysfunction-associated steatotic liver disease is becoming a leading etiology of end-stage liver disease and HCC. Simultaneous liver transplantation and sleeve gastrectomy (LT-SG) have been proposed in the United States, but the safety and efficacy of the procedure have not been widely explored in Europe. Between January 2016 and December 2022, morbidly obese patients listed for liver transplantation at Tor Vergata University were enrolled in the LT-SG study. Primary outcomes were (1) safety expressed as 30- and 90-day overall survival and (2) major postoperative complications (Clavien-Dindo >IIIa). The secondary outcome was efficacy expressed as a 3-year %excess body mass index (BMI) loss. Eleven patients were enrolled in the study. The median BMI at transplantation was 42 (IQR 38-48). Indications of LT-SG were HCC (63.6%) and cirrhosis (36.4%). In 54% of cases, donors had high-risk characteristics (eurotransplant donor risk index >1.6). The 30- and 90-day overall survival were 63.6% and 54.5%, respectively. All deaths occurred in patients with P-SOFT >15 or in patients who had at least 3 of the following characteristics: >60 years, BMI >45, metabolic syndrome, MELD >25 or eurotransplant donor risk index >1.6. The 6 months, 1, 2, and 3 years %excess BMI loss was 73%, 60%, 50%, and 43%, respectively. LT-SG is a complex procedure that may carry excess risk in an unselected population. It should be considered only in highly selected patients. Standard donors are recommended, and prioritization of severely obese patients on the waiting list should be considered.

Results of a fast-track referral system for urgent outpatient hepatology visits

OBJECTIVE

In 2011, our regional district adopted an experimental system for fast referral (within 72 h) by general practitioners to several outpatient specialist evaluations including hepatology. The aim of this study was to assess the characteristics and appropriateness of urgent hepatology visits.

DESIGN

Retrospective study.

SETTING

Hospital-based study in Italy.

PARTICIPANTS

A total of 192 subjects referred to our outpatient hepatology clinic classified as 'urgent' were compared with 397 patients evaluated with standard referral. A comparison with 200 patients visited just before the adoption of the new system was also included.

MAIN OUTCOME MEASURES

Patients' features and appropriateness of referral in urgent and non-urgent groups using the new system.

RESULTS

Increase in liver enzymes was the main factor that leads to specialist hepatology consultation and was more frequent in the urgent group (37% vs. 27.1%, P < 0.001). Liver malignancies were identified in 2.6% of patients in the urgent group, whereas this percentage was 10 times lower in the non-urgent group (P = 0.01). Urgent patients required inpatient admission more frequently compared with non-urgent patients (4.2% vs. 0.5%; P = 0.003). Inappropriate referral was recorded in 41% of cases in the urgent group (no reason for urgency 27%; condition not attributable to liver 13.5%). In the non-urgent group, consultations were inappropriate in 20.1% of cases (condition not attributable to liver). In comparison with the old system, the new one allocated >85% of patients with serious illness to urgent group.

CONCLUSIONS

This strategy is helpful in selecting patients with more serious hepatic conditions. Appropriateness of referral represents a crucial issue.

One-year pilot study on tauroursodeoxycholic acid as an adjuvant treatment after liver transplantation

BACKGROUND

The usefulness of ursodeoxycholic acid after liver transplantation is controversial. Tauroursodeoxycholic acid, the natural taurine-amidate, is a highly hydrophilic and cytoprotective bile salt currently under investigation.

AIMS

To investigate the clinical usefulness of tauroursodeoxycholic acid after liver transplantation.

PATIENTS

Thirty-three patients undergoing liver transplantation entered the study.

METHODS

Sixteen patients were randomized to receive tauroursodeoxycholic acid (250 b.i.d. for 12 months) and 17 served as controls. Tauroursodeoxycholic acid was given from day 5 after transplantation for one year.

RESULTS

Tauroursodeoxycholic acid treatment was safe and well tolerated. No drop outs occurred. Among the 29 patients undergoing long-term follow-up, five deaths occurred (3 of whom in the tauroursodeoxycholic acid group), none of which was related to treatment. The one-year actuarial survival was 78.6% in patients treated with tauroursodeoxycholic acid and 86.7% in controls (n.s.). No differences were observed with respect to early or late graft function and survival, nor to acute cellular rejection. Tauroursodeoxycholic acid therapy was associated with lower serum cholesterol levels (p < 0.02) during the early postoperative months; with milder cholestasis; with a drop in biliary cholates but no changes in endogenous hydrophobic bile salts.

CONCLUSIONS

Long-term treatment with low dose tauroursodeoxycholic acid after liver transplantation is safe but does not affect graft function and survival.

Renal Function, Adherence and Quality of Life Improvement After Conversion From Immediate to Prolonged-Release Tacrolimus in Liver Transplantation: Prospective Ten-Year Follow-Up Study

Immunosuppression non-adherence is a major cause of graft failure after liver transplantation. The aim of this study was to evaluate practice surrounding conversion from immediate-release to prolonged-release Tacrolimus formulation and to assess patient adherence and quality of life (QoL). One hundred and seven adult liver transplant recipients, receiving immediate-release Tacrolimus for a minimum of 6 months, were converted to prolonged-release formulation, based on a dose ratio of one (1:1). The median follow-up was 120 [IQR, 120-123] months. Tacrolimus dosage and blood level, liver and renal function, lipid and glucose profiles were recorded. In addition, questionnaires were submitted to evaluate adherence and QoL following conversion. No rejection was recorded. The median serum Tacrolimus blood level decreased over 1 month (5.80, [IQR, 2.0-10.8] vs. 3.8 [IQR, 1.4-8.7]; p < 0.0005). Significant improvement in renal function was noted (median GFR was 81.7 [IQR, 43.4-128.6] vs. 73.9 [IQR, 27.1-130.2]; p = 0.0002). At the end of the follow-up, conversion resulted in an overall decrease in non-adherence of 53.3% (p = 0.0001) and an improvement in QoL was reported by 76.2% of patients. Thus, 1:1 conversion from immediate to prolonged-release Tacrolimus is safe, feasible and efficient, avoiding under-therapeutic and toxic peak concentrations, improving renal function, adherence to immunosuppression and overall patient QoL.

Gastrointestinal endoscopy in cirrhotic patient: Issues on the table

Patients with liver cirrhosis are fragile and present specific clinical hallmarks. When undergoing to gastrointestinal (GI) endoscopy, these subjects require an individual pre evaluation, taking into account: Level of haemostasis impairment, the individual risk of infection, the impact of sedation on hepatic encephalopathy and other factors. The overall assessment of liver function, employing common scoring systems, should be also assessed in the preprocedural phase. Beside some common general problems, regarding GI endoscopy in cirrhotic subjects, also specific issues are present for some frequent indications or procedures. For instance, despite an increased incidence of adenomas in cirrhosis, colon cancer screening remains suboptimal in subjects with this disease. Several studies in fact demonstrated liver cirrhosis as a negative factor for an adequate colon cleansing before colonoscopy. On the other hand, also the routine assessment of gastroesophageal varices during upper GI endoscopy presents some concern, since important inter-observer variability or incomplete description of endoscopic findings has been reported in some studies. In this review we discussed in details the most relevant issues that may be considered while performing general GI endoscopic practice, in patient with cirrhosis. For most of these issues there are no guidelines or clear indications. Moreover until now, few studies focused on these aspects. We believe that targeting these issues with corrective measures may be helpful to develop a tailored endoscopic approach for cirrhosis, in the future.

Development and Validation of a Scoring System to Predict Response to Obeticholic Acid in Primary Biliary Cholangitis

BACKGROUND & AIMS

Obeticholic acid (OCA) is the only licensed second-line therapy for primary biliary cholangitis (PBC). With novel therapeutics in advanced development, clinical tools are needed to tailor the treatment algorithm. We aimed to derive and externally validate the OCA response score (ORS) for predicting the response probability of individuals with PBC to OCA.

METHODS

We used data from the Italian RECAPITULATE (N = 441) and the IBER-PBC (N = 244) OCA real-world prospective cohorts to derive/validate a score including widely available variables obtained either pre-treatment (ORS) or also after 6 months of treatment (ORS+). Multivariable Cox regressions with backward selection were applied to obtain parsimonious predictive models. The predicted outcomes were biochemical response according to POISE (alkaline phosphatase [ALP]/upper limit of normal [ULN]<1.67 with a reduction of at least 15%, and normal bilirubin), or ALP/ULN<1.67, or normal range criteria (NR: normal ALP, alanine aminotransferase [ALT], and bilirubin) up to 24 months.

RESULTS

Depending on the response criteria, ORS included age, pruritus, cirrhosis, ALP/ULN, ALT/ULN, GGT/ULN, and bilirubin. ORS+ also included ALP/ULN and bilirubin after 6 months of OCA therapy. Internally validated c-statistics for ORS were 0.75, 0.78, and 0.72 for POISE, ALP/ULN<1.67, and NR response, which raised to 0.83, 0.88, and 0.81 with ORS+, respectively. The respective performances in validation were 0.70, 0.72, and 0.71 for ORS and 0.80, 0.84, and 0.78 for ORS+. Results were consistent across groups with mild/severe disease.

CONCLUSIONS

We developed and externally validated a scoring system capable to predict OCA response according to different criteria. This tool will enhance a stratified second-line therapy model to streamline standard care and trial delivery in PBC.

Serum Levels of Granulocyte-Macrophage-colony-stimulating Factor and Stem-cell Factor During Liver Regeneration after Partial Hepatectomy in Humans

BACKGROUND

Multiple biological functions have been recognized regarding Granulocyte Macrophage-Colony Stimulating Factor (GM-CSF) and Stem Cell Factor (SCF).

AIM

To evaluate the serum changes of GM-CSF and SCF in patients undergoing surgical resection for liver tumor, in the regenerative phase after surgery in order to identify the possible relationship with the patient, tumor or surgical variables.

METHODS

Thirty-two consecutive patients (50% male, median age 66), undergoing hepatic resection of liver neoplasm, were evaluated. The liver tumor was Hepatocellular Carcinoma (HCC) in 44% of cases. Other tumors were cholangiocarcinoma and metastasis. Serum levels of GM-CSF and SCF were assessed at baseline and 2 days, 7 days and 4 weeks after surgery. Personal and clinical patient data were also recorded. The statistical analysis was carried out using t-test for unpaired data or ANOVA (repeated measure) for continuous variables and Fisher test for discrete variables.

RESULTS

GM-CSF levels remained constant after surgery and were compared to baseline values. SCF levels, on the other hand, increased during the time, after surgery. The evaluation of SCF levels (fold increase) according to surgical, patient and tumor variables evidenced some differences. At day 7 and week 4, SCF levels were statistically increased: i) in patients undergoing a large resection in comparison with others (p<0.05); ii) in patients non-cirrhotic in comparison with cirrhotic ones (p=0.02) and finally; iii) in patients with non-HCC tumor in comparison with HCC ones (p=0.02).

CONCLUSION

During liver regeneration in humans, SCF serum levels are increased allowing to hypothesize a possible role of this chemokine during tissue growth and remodeling.