G. Mennini

Human OX40 tunes the function of regulatory T cells in tumor and nontumor areas of hepatitis C virus–infected liver tissue

Regulatory T cells (Tregs) can be considered as a mixed population of distinct subsets, endowed with a diverse extent and quality of adaptation to microenvironmental signals. Here, we uncovered an opposite distribution of Treg expansion, phenotype, and plasticity in different microenvironments in the same organ (liver) derived from patients with chronic hepatitis C: On the one side, cirrhotic and tumor fragments were moderately and highly infiltrated by Tregs, respectively, expressing OX40 and a T‐bethighIFN‐γ– “T‐helper (Th)1‐suppressing” phenotype; on the other side, noncirrhotic liver specimens contained low frequencies of Tregs that expressed low levels of OX40 and highly produced interferon‐gamma (IFN‐γ; T‐bet+IFN‐γ+), thus becoming “Th1‐like” cells. OX40‐expressing and Th1‐suppressing Tregs were enriched in the Helios‐positive subset, carrying highly demethylated Treg cell‐specific demethylated region that configures committed Tregs stably expressing forkhead box protein 3. OX40 ligand, mostly expressed by M2‐like monocytes and macrophages, boosted OX40+ Treg proliferation and antagonized the differentiation of Th1‐like Tregs. However, this signal is counteracted in noncirrhotic liver tissue (showing various levels of inflammation) by high availability of interleukin‐12 and IFN‐γ, ultimately leading to complete, full Th1‐like Treg differentiation. Conclusion: Our data demonstrate that Tregs can finely adapt, or even subvert, their classical inhibitory machinery in distinct microenvironments within the same organ. (Hepatology 2014;60:1494–1507)

Falsely elevated tacrolimus concentrations measured using the ACMIA method due to circulating endogenous antibodies in a kidney transplant recipient

BACKGROUND Therapeutic monitoring of whole-blood concentration of tacrolimus, a potent immunosuppressive drug used after organ transplantation, is essential to avoid toxic effects and to maintain the correct dosage. Although the reference method for the determination of tacrolimus concentrations is LC-MS/MS, several certified immunoassays are widely used for routine examinations. We report falsely elevated blood tacrolimus concentrations using the antibody-conjugated magnetic immunoassay (ACMIA) from Siemens Healthcare Diagnostics for the analysis of a patient who had undergone renal transplantation. METHODS Whole-blood samples from a patient with elevated tacrolimus concentrations not consistent with the clinical picture were analysed with an alternative immunoassay and were investigated for interference by performing double dilution tests, by incubating in heterophilic blocking tubes and by evaluating plasmatic interfering factors. RESULTS Double dilution tests showed a clear nonlinearity, suggesting that antibody interference not related to heterophilic antibodies had occurred; false-positive concentrations of cyclosporin obtained when using an antibody-conjugated to β-galactosidase suggested the presence of endogenous antibodies directed against β-galactosidase. CONCLUSION In patients receiving tacrolimus, continued surveillance by laboratory staff and clinicians is necessary when using a method not requiring external pre-treatment, such as the Siemens ACMIA method.

Pediatric Acute Liver Failure With Molecular Adsorbent Recirculating System Treatment

BACKGROUND The prognosis of pediatric acute liver failure (PALF) has been significantly improved by emergency orthotopic liver transplantation (OLT). Since 2004, the molecular adsorbent recirculating system (MARS) has been proposed as a bridging procedure. The aim of our study was to assess its efficacy in children with PALF. PATIENTS AND METHODS Since 1999 we performed treatment of 39 fulminant hepatic failure (FHF) cases with MARS. Since September 2004 we treated 6 pediatric patients with FHF who were of mean age 10.6 years (range, 3-15 years) including 4 females and 2 males. In 3 cases the cause of FHF was unknown; in 2 cases, it was induced by paracetamol overdose; and in 1, by acute hepatitis B virus. Inclusion criteria were: bilirubin >15 mg/dL; creatinine >or=2 mg/dL; encephalopathy grade >II; and International normalized ratio (INR) >2.5. Other estimated parameters were: AST and ALT serum levels, lactate, and urine volume. Neurological status was monitored using the Glasgow Coma Scale (GCS). Continuous MARS treatment was performed in all patients with a kit change every 8 hours. Intensive care unit (ICU) treatment was applied to optimize regeneration and to prevent cardiovascular complications. RESULTS We observed a significant improvement among levels of bilirubin (P< .009), ammonia (P< .005), creatinine (P< .02), GCS (P< .002), and predictive criteria and as Sequential Organ Failure Assessment (SOFA) and Pediatric End-Stage Liver Disease (PELD). Three children underwent OLT: 1 died after 5 days due to primary nonfunction and 2 children are alive after a median follow-up of 14 months. In 2 children the MARS treatment led to resolution of clinical status without liver transplantation. One child died before OLT due to sepsis and multiorgan failure. CONCLUSIONS We concluded that application of the MARS liver support device in combination with experienced ICU management contributed to improve the clinical status in children with PALF awaiting liver transplantation.

Preharvest donor hyperoxia predicts good early graft function and longer graft survival after liver transplantation

A total of 44 donor/recipient perioperative and intraoperative variables were prospectively analyzed in 89 deceased‐donor liver transplantations classified as initial good graft function (IGGF) or initial poor graft function (IPGF) according to a scoring system based on values obtained during the 1st 72 postoperative hours from the serum alanine aminotransferase (ALT) concentration, bile output, and prothrombin activity. The IGGF compared with the IPGF group showed: 1) longer graft (P = .002) and patient (P = .0004) survival; 2) at univariate analysis, a higher (mean [95% confidence interval]) preharvest donor arterial partial pressure of oxygen (PaO2) (152 [136‐168] and 104 [91‐118] mmHg, respectively; P = .0008) and arterial hemoglobin oxygen saturation (97.9 [97.2‐98.7] and 96.7 [95.4‐98.0]%, respectively; P = .0096), a lower percentage of donors older than 65 years (13 and 33%, respectively; P = .024), a lower percentage of donors treated with noradrenaline (16 and 41%, respectively; P = .012). At multivariate analysis, IGGF was associated positively with donor PaO2 and negatively with donor age greater than 65 years and with donor treatment with noradrenaline. Independently from the grouping according to initial graft function, graft survival was longer when donor PaO2 was >150 mmHg than when donor PaO2 was ≤150 mmHg (P = .045). In conclusion, preharvest donor hyperoxia predicts IGGF and longer graft survival. (Liver Transpl 2005;11:140–151.)

Chronic kidney disease after liver transplantation: pretransplantation risk factors and predictors during follow-up.

Background Chronic renal impairment is an emerging problem in the management of patients after liver transplantation (LT). Methods We prospectively analyzed predictors of chronic kidney disease (CKD) after LT in 179 patients followed for a median of 63 months. Diagnosis of CKD was based on an estimated glomerular filtration rate (GFR) of less than 60 mL/min according to the current position statement from the Kidney Disease Improving Global Outcome. Pretransplantation risk factors were evaluated. A Cox regression analysis, with time-dependent variables evaluated during follow-up, was applied to realize a prognostic model for CKD, and a prognostic index was also calculated. The validity of the model was tested in 149 independent LT patients with a median follow-up of 46 months. Results The cumulative incidence of CKD was 45% at 5 years after LT. Estimated GFR at LT was the only pretransplantation independent risk factor (beta, 0.33; standard error (beta), 0.07; 95% confidence interval, 0.95–0.98). Development of arterial hypertension (hazards ratio [HR], 1.83), episodes of severe infection (HR, 2.15), and estimated GFR (HR, 0.89) after LT were identified as independent prognostic factors at the Cox regression time-dependent analysis. The model was able to identify the patients at higher risk for the development of CKD in the validation set. Conclusions Lower renal function at transplantation is associated with a higher risk of CKD after transplantation. A predictive model based on the variation of posttransplantation variables during the course of follow-up can help the clinicians to estimate the probability of CKD in the next 12 months.

Combined Liver-Kidney Transplantation in Polycystic Disease: Case Reports

Polycystic disease causes a progressive decrease in renal function and liver degeneration. The progression of the disease evolves separately between organs and transplantation options vary: simultaneous or sequential liver-kidney transplantation or single-organ transplantation. From September 2006 to June 2007 3 combined liver kidney transplantations (CLKT) were performed for polycystic disease with end-stage renal disease: 2 with polycystic liver disease, and 1 with hepatic failure due to congenital hepatic fibrosis. The widest dimensions of the polycystic liver of 50 and 60 cm diameter were due to extensive cystic degeneration. We performed 1 simultaneous CLKT and 2 sequential transplantations: 1 liver after kidney, and 1 kidney after liver. At present all patients are alive with 100% graft function. Median creatinine level at discharge was 0.9 mg/dL (ranges, +/-0.2). Good liver graft function was reported in all 3 cases. Transplant benefit in polycystic liver-kidney disease has been already demonstrated; conservative surgical options may result in a high incidence of complications in highly involved polycystic livers. Delaying transplantation results in a more difficult surgical technique, a higher rate of postoperative complications, and a disturbance of optimal graft retrieval because of the worse preoperative condition of the patients.

Giant hemangiomas of the liver: surgical strategies and technical aspects

The incidence of hemangiomas is 2-7% in the general population. We evaluated more than 300 patients with hepatic hemangiomas. Surgical removal of hepatic hemangiomas was performed in 48 cases due to uncertain diagnosis (2 cases), intractable symptoms (26 cases), size increase (18 cases), and liver failure in 2 cases that were treated by hepatic transplantation. In all, 26 patients underwent enucleation of hemangiomas or segmentectomies, while the remaining 20 patients underwent right lobectomies or left lateral segmentectomies. Blood transfusions were required in four cases (including two liver transplants); mean post-resection hospital stay was 6.3 days. We observed no perioperative mortality and only two cases of major morbidity (bile leaks not requiring reoperation). Our experience confirms that, after adequate patient selection, surgical treatment of hepatic hemangiomas is a very effective therapeutic choice with no mortality and low morbidity.

Preoperative donor scores and postoperative early measures of graft function: relevance to the outcome of liver transplantation.

BACKGROUND Several donor and recipient parameters play a role in the determination of post-liver transplant allograft function. The identification of prognostic indices presents great implications for correct allocation of donors and more targeted recipient management. The aim of our review was to detect the role of preoperative scoring systems and early postoperative measures of graft function as predictive factors for the development of graft failure and recipient death. METHODS We stratified a cohort of 97 patients in two groups according to a 1-year functional (Group A; n = 72) versus non-functional (Group B; n = 25) status of the allograft. RESULTS Patients in group B showed higher preoperative Model for End-stage Liver Disease (MELD) values, longer warm ischemia times, reduced bile outputs and increased peak values of transaminases and INR content within the first 3 days after transplantation. Group B showed 48% of patients with initial poor graft function. The parameters which resulted in a significant prediction of graft loss by multivariate analysis were MELD (P = .012); postoperative day 1 serum alanine aminotransferase (ALT) (P < .0001) and day 3 ALT (P = .003). The predictive factors for patient death were postoperative day 1 serum ALT (P < .0001) and day 3 ALT (P = .001). CONCLUSIONS MELD score was a useful preoperative parameter for the prediction of post-transplant graft survival. Early ALT values predicted both graft and recipient survivals. Minimization of parameters related to their peaks (warm ischemia time) may improve graft and patients survival rates.

Intention-to-treat survival benefit of liver transplantation in patients with hepatocellular cancer

The debate about the best approach to select patients with hepatocellular cancer (HCC) waiting for liver transplantation (LT) is still ongoing. This study aims to identify the best variables allowing to discriminate between “high‐” and “low‐benefit” patients. To do so, the concept of intention‐to‐treat (ITT) survival benefit of LT has been created. Data of 2,103 adult HCC patients consecutively enlisted during the period 1987‐2015 were analyzed. Three rigorous statistical steps were used in order to create the ITT survival benefit of LT: the development of an ITT LT and a non‐LT survival model, and the individual prediction of the ITT survival benefit of LT defined as the difference between the median ITT survival with (based on the first model) and without LT (based on the second model) calculated for each enrolled patient. Four variables (Model for End‐Stage Liver Disease, alpha‐fetoprotein, Milan‐Criteria status, and radiological response) displayed a high effect in terms of delta benefit. According to these risk factors, four benefit groups were identified. Patients with three to four factors (“no‐benefit group”; n = 405 of 2,103; 19.2%) had no benefit of LT compared to alternative treatments. Conversely, patients without any risk factor (“large‐benefit group”; n = 108; 5.1%) yielded the highest benefit from LT reaching 60 months. Conclusion: The ITT transplant survival benefit presented here allows physicians to better select HCC patients waiting for LT. The obtained stratification may lead to an improved and more equitable method of organ allocation. Patients without benefit should be de‐listed, whereas patients with large benefit ratio should be prioritized for LT. (Hepatology 2017;66:1910–1919)

Does Caval Reconstruction Technique Affect Early Graft Function after Liver Transplantation? A Preliminary Analysis

BACKGROUND In the past decades, the inferior vena cava (IVC) reconstruction technique has undergone several evolutions, such as biopump, piggyback technique (PB), and laterolateral approach (LLPB). Several advantages are reported comparing the PB technique to biopump use. However, comparison between PB and LLPB has not been as well investigated. The aim of this study was to compare the results in terms of immediate graft function and intermediate graft survival among 3 subgroups characterized by distinct caval reconstruction techniques. METHODS We retrospectively analyzed a cohort of 200 consecutive adult patients who underwent liver transplantation from January 2001 to December 2009. The patients were stratified according to 3 caval reconstructive techniques: biopump (n=135), PB (n=32) and LLPB (n=33). RESULTS The LLPB group showed the shortest cold and warm ischemia times and the best immediate postoperative graft function. Survival analysis revealed LLPB patients to present the best 1-year graft survival rates: namely, 90.9% versus 75.0% and 74.1% among the PB and biopump groups, respectively (log-rank tests: LLPB vs biopump: P=.03; LLPB vs PB: P=.05). In our experience, LLPB showed the best graft survivals with an evident reduction in both cold and warm ischemia times. However, it is hard to obtain an irrefutable conclusion owing to the retrospective nature of this study, the small sample, and the different periods in which the groups were transplanted. CONCLUSIONS LLPB technique was a safe procedure that minimized the sequelal of ischemia-reperfusion damage. This technique yielded results superior to venovenous bypass. No definitive conclusions can to be obtained in this study comparing classic PB or LLPB.