Effect of mycophenolic acid on inosine monophosphate dehydrogenase (IMPDH) activity in liver transplant patients.

BACKGROUND: Due to the development of immunosuppressants, the focus in transplanted patients has shifted from short-term to long-term survival as well as a better adjustment of these drugs in order to prevent over- and under-immunosuppression. Mycophenolic acid (MPA) is a noncompetitive inhibitor of inosine monophosphate dehydrogenase (IMPDH) and approved for prophylaxis of acute rejection after kidney, heart, and liver transplantation, where it has become a part of the standard therapy. Targeting inosine monophosphate IMPDH activity as a surrogate pharmacodynamic marker of MPA-induced immunosuppression may allow a more accurate assessment of efficacy and aid in limiting toxicity in liver transplanted patients. AIM: Assess IMPDH-inhibition in liver transplant recipients and its impact on biliary/infectious complications, acute cellular rejection (ACR) and liver dependent survival. METHODS: This observational cohort study comprises 117 liver transplanted patients that were treated with mycophenolate mofetil (MMF) for at least 3 months. Blood samples (BS) were collected and MPA serum level and IMPDH activity were measured before (t(0)), 30minutes (t(30)) and 2h after (t(120)) MMF morning dose administration. Regarding MPA, we assessed the area under the curve (AUC). Patients were prospectively followed up for one year and assessed for infectious and biliary complications, episodes of ACR and liver dependent survival. RESULTS: The MPA levels showed a broad interindividual variability at t(0) (2.0±1.8ng/ml), t(30) (12.7±9.0ng/ml) and t(120) (7.5±4.3ng/ml). Corresponding IMPDH activity was at t(o) (23.2±9.5 nmol/h/mg), at t(30) (16.3±8.8 nmol/h/mg) and t(120) (18.2±8.7 nmol/h/mg). With regard to MPA level we found no correlation with infectious or biliary complications within the follow-up period. Patients with baseline IMPDH(a) below the median had significant more viral infections (6 (10.2%) vs. 17 (29.3%); P=0.009) with especially more cytomegalovirus (CMV) infections (1 (3.4%) vs. 6 (21.4%); P=0.03)). Furthermore, patients with baseline IMPDH(a) above the median developed more often non-anastomotic biliary strictures (8 (13.6%) vs. 1 (1.7%), P=0.03). We found the group reaching the combined clinical endpoint of death and re-transplantation showing significantly lower MPA baseline values (t(0) 0.9±0.7 vs. 2.1±1.8µg/ml Mann-Whitney-U: P=0.02). We calculated a simplified MPA(AUC) with the MPA level at baseline, 30 and 120minutes after MPA administration. Whereas we found no differences with regard to baseline characteristics at entry into the study patients with MPA (AUC) below the median experienced significantly more often the combined clinical endpoint (12.1% (7/58) vs. 0.0% (0/57); P=0.002) and had a reduced actuarial re-transplantation-free survival (1.0 year vs. 0.58 years; Log-rank: P=0.007) during the prospective one-year follow-up period. In univariate and multivariate analysis including gender, age, BMI, ACR, MPA (AUC) and IMPDH(a) only BMI, MPA (AUC) and IMPDH(a) were independently associated with reduced actuarial re-transplantation-free survival. CONCLUSION: MPA-levels and IMPDH-activity in liver transplanted patients allows individual risk assessment. Patients with higher IMPDH inhibition acquire more often viral infections. Insufficient IMPDH inhibition is associated with development of non-anastomotic bile duct strictures and reduced re-transplantation-free survival.

Pathological features of primary sclerosing cholangitis identified by bile proteomic analysis.

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease of unknown origin. Previous bile proteomic analyses in patients with PSC have revealed changes in disease activity specific to malignant transformation. In this study, we established a reference bile duct-derived bile proteome for PSC that can be used to evaluate biliary pathophysiology. Samples were collected from patients with PSC or with choledocholithiasis (control) (n=6 each). Furthermore, patients with PSC-associated cholangiocarcinoma (CC) and with CC without concomitant PSC were analyzed. None of the patients showed signs of inflammation or infection based on clinical and laboratory examinations. Proteins overexpressed in patients with PSC relative to control patients were detected by two-dimensional difference gel electrophoresis and identified by liquid chromatography-tandem mass spectrometry. Functional proteomic analysis was performed using STRING software. A total of 101 proteins were overexpressed in the bile fluid of patients with PSC but not in those of controls; the majority of these were predicted to be intracellular and related to the ribosomal and proteasomal pathways. On the other hand, 91 proteins were found only in the bile fluid of controls; most were derived from the extracellular space and were linked to cell adhesion, the complement system, and the coagulation cascade. In addition, proteins associated with inflammation and the innate immune response-e.g., cluster of differentiation 14, annexin-2, and components of the complement system-were upregulated in PSC. The most prominent pathways in PSC/CC-patients were inflammation associated cytokine and chemokine pathways, whereas in CC-patients the Wnt signaling pathway was upregulated. In PSC/CC-patients DIGE-analysis revealed biliary CD14 and Annexin-4 expression, among others, as the most prominent protein that discriminates between both cohorts. Thus, the bile-duct bile proteome of patients with PSC shows disease-specific changes associated with inflammation and the innate immune response even in the absence of obvious clinical signs of cholangitis, malignancy, or inflammation. This article is part of a Special Issue entitled: Cholangiocytes in Health and Diseaseedited by Jesus Banales, Marco Marzioni and Peter Jansen.

HLA haplotypes in primary sclerosing cholangitis patients of admixed and non-European ancestry.

Primary sclerosing cholangitis (PSC) is strongly associated with several human leukocyte antigen (HLA) haplotypes. Due to extensive linkage disequilibrium and multiple polymorphic candidate genes in the HLA complex, identifying the alleles responsible for these associations has proven difficult. We aimed to evaluate whether studying populations of admixed or non-European descent could help in defining the causative HLA alleles. When assessing haplotypes carrying HLA-DRB1*13:01 (hypothesized to specifically increase the susceptibility to chronic cholangitis), we observed that every haplotype in the Scandinavian PSC population carried HLA-DQB1*06:03. In contrast, only 65% of HLA-DRB1*13:01 haplotypes in an admixed/non-European PSC population carried this allele, suggesting that further assessments of the PSC-associated haplotype HLA-DRB1*13:01-DQA1*01:03-DQB1*06:03 in admixed or multi-ethnic populations could aid in identifying the causative allele.

[Expert recommendations: Hepatitis C and transplantation]. / Empfehlungen zur antiviralen Therapie der chronischen Hepatitis C bei Patienten auf der Warteliste und nach Transplantation.

With the approval of new direct acting antiviral agents (DAA), therapeutic options for patients with chronic hepatitis C virus (HCV) infection are now generally available before and after liver transplantation (LT). Interferon-free DAA regimens are highly effective therapies and provide a good safety profile. However, the body of clinical evidence in this patient population is limited and the best treatment strategies for patients on the waiting list with (de)compensated cirrhosis and after LT are not well defined. The following recommendations for antiviral therapy in the context of LT are based on the currently available literature and clinical experience of experts in the field, and have been discussed in an expert meeting. The aim of this article is to guide clinicians in the decision making when treating patients before and after LT with DAAs.

Cardiac volume overload and pulmonary hypertension in long-term follow-up of patients with a transjugular intrahepatic portosystemic shunt.

BACKGROUND: Transjugular intrahepatic portosystemic shunt (TIPSS) cause haemodynamic changes in patients with cirrhosis, yet little is known about long-term cardiopulmonary outcomes. AIM: To evaluate the long-term cardiopulmonary outcome after TIPSS. METHODS: We evaluated cardiopulmonary parameters including echocardiography during long-term follow-up after TIPSS. Results at 1-5 years after TIPSS were compared to those of cirrhotic controls. Pulmonary hypertension (PH) diagnoses rates were included. Endothelin 1, thromboxane B2 and serotonin were measured. RESULTS: We found significant differences 1-5 years after TIPSS compared to pre-implantation values: median left atrial diameter (LAD) increased from 37 mm [interquartile range (IQR): 33-43] to 40 mm (IQR: 37-47, P = 0.001), left ventricular end-diastolic diameter (LV-EDD) increased from 45 mm (range: 41-49) to 48 mm (IQR: 45-52, P < 0.001), pulmonary artery systolic pressure (PASP) increased from 25 mmHg (IQR: 22-33) to 30 mmHg (IQR: 25-36, P = 0.038). Comparing results 1-5 years post-implantation to the comparison cohort revealed significantly higher (P < 0.05) LAD, LV-EDD and PASP values in TIPSS patients. PH prevalence was higher in the shunt group (4.43%) compared to controls (0.91%, P = 0.150). Thromboxane B2 levels correlated with PASP in the TIPSS cohort (P = 0.033). There was no transhepatic gradient observed for the vasoactive substances analysed. CONCLUSIONS: TIPSS placement is accompanied by long-term cardiovascular changes, including cardiac volume overload, and is associated with an increased rate of pulmonary hypertension. The need for regular cardiac follow-up after TIPSS requires further evaluation.

[Complication management after liver transplantation. Increasing patient safety by standardized approach and interdisciplinary cooperation]. / Komplikationsmanagement nach Lebertransplantation. Erhöhung der Patientensicherheit durch standardisiertes Vorgehen und interdisziplinäre Kooperation.

The interdisciplinary management of postoperative complications in liver transplantation is of extreme importance. Due to organ shortage and prioritization of the most severely ill recipients in the model for end-stage liver disease (MELD)-based allocation, both donor and recipient associated morbidity are increasing. An interdisciplinary, structured monitoring concept is essential for the timely identification and specific treatment of postoperative complications. Interdisciplinary clinical rounds, laboratory testing and Doppler ultrasound monitoring of the graft perfusion are as important as comprehensive anti-infection prophylaxis and immunosuppression. Arterial perfusion disorders of any kind, biliary complications and postoperative fluid accumulation demand individualized therapeutic concepts. In summary, the success of liver transplantation depends on the communication and coordinated interdisciplinary cooperation of all disciplines involved.

NK cell development in bone marrow and liver: site matters.

The NKp46 protein is found on resting and activated natural killer (NK) cells and is involved in the recognition of malignant and infected cells. The expression of NKp46 is believed to precede that of DX5 in early NK cell development. We show that this is not the case in the bone marrow (BM). Here, NKp46 is predominantly expressed after DX5, whereas the liver harbors a subpopulation that expresses NKp46 but not DX5. NK cell precursors in the liver show much lower levels of Eomesodermin than NK cell precursors in the BM, although they express higher levels of granzymes and unlike the NK cell precursors in the BM are fully able to degranulate and produce interferon gamma (IFN-γ). The development of NK cells thus differs between the two organs. This needs to be considered when using NKp46 and DX5 as NK cell markers and when performing NK cell-specific gene deletion in Ncr1 transgenic mice.

Reduction in alkaline phosphatase is associated with longer survival in primary sclerosing cholangitis, independent of dominant stenosis.

BACKGROUND: Alkaline phosphatase (ALP) is an important serum marker in primary sclerosing cholangitis (PSC). Patients with obstruction of the large bile ducts due to dominant strictures (DS) are a special, clinically important phenotype. AIM: To determine the impact of ALP reduction on liver transplantation-free survival in PSC patients with DS. METHODS: Prospective cohort study in 215 PSC patients. We performed subgroup analysis for patients without DS (no DS, n = 84), DS at first presentation (DS early, n = 72) and development of DS during the course of the study (DS late, n = 59). We evaluated two scores of ALP reduction. ALP reduction 1 was defined as ALP normalisation, 50% reduction compared with baseline values, or reduction below 1.5 times of upper limit of normal (ULN) within 6 months. ALP reduction 2 was defined as ALP reduction below 1.5 times of ULN within 12 months. RESULTS: Of the patients, 59.5% reached an ALP reduction 1 and 56.7% according to ALP reduction 2. Achievement of each score was associated with longer transplantation-free survival in all three groups (ALP reduction 1: no DS P = 0.001; DS early P < 0.001; DS late P = 0.022; ALP reduction 2: no DS P = 0.014; DS early P = 0.001; DS late P = 0.002). Cox-regression analysis revealed each score as an independent predictor for improved transplantation-free survival (ALP reduction 1 and 2 P < 0.001 each). We further analysed previously published scores of ALP improvement in PSC showing also improved survival in patients with ALP normalisation or a reduction below 1.5 times of ULN (P = 0.003, P = 0.001, respectively), whereas the score determined by 40% reduction did not show significant differences in survival (P = 0.55). CONCLUSIONS: Reduction in alkaline phosphatase values within the first year is associated with improved transplantation-free survival in patients with primary sclerosing cholangitis independent of the presence of dominant strictures. Alkaline phosphatase might be an adequate surrogate marker for outcome assessment in clinical studies both for patients with and without dominant strictures.

Fut2 genotype is a risk factor for dominant stenosis and biliary candida infections in primary sclerosing cholangitis.

BACKGROUND: A recent genome-wide association study identified the FUT2 secretor status and genotype defined by the single-nucleotide polymorphism rs601338 as potential genetic risk factor in primary sclerosing cholangitis (PSC), which significantly influences biliary bacterial composition. AIM: To determine the impact of the rs601338-FUT2 genotype on frequency of biliary infections, development of dominant stenosis and liver-transplantation-free survival in patients with PSC. METHODS: Cohort study of 215 patients with PSC treated at our tertiary care centre with respect to their rs601338-FUT2 genotype. Results of endoscopic retrograde cholangiography and bile culture were analysed; 639 biliary samples were obtained, cultured and subjected to microbial analysis. Clinical and laboratory data were analysed using chart reviews. RESULTS: For the rs601338-FUT2 genotype, 69 patients (32.1%) were found to be wildtype (GG), 97 (45.1%) patients were heterozygous (AG) and 49 patients (22.8%) were homozygous-mutated (AA). In addition to alterations in the bacterial pattern, especially in heterozygous carriers, patients with mutated alleles had a marked increase in the frequency of biliary Candida infections (P = 0.025). Further, patients with mutated alleles showed an increased frequency of episodes of cholangitis (P = 0.0025), development of dominant stenosis (P < 0.002) and a reduced actuarial transplantation-free survival (P = 0.044). Levels of biliary Ca19-9 were significantly elevated in the homozygous-mutated patients. CONCLUSIONS: The rs601338-FUT2 genotype is strongly associated with episodes of cholangitis, fungobilia and the incidence of dominant stenosis, which are three clinical hallmarks of PSC; FUT2 is thus an important genetic risk factor for host-microbial diversity and disease progression in PSC.

Everolimus and early calcineurin inhibitor withdrawal: 3-year results from a randomized trial in liver transplantation.

The feasibility of de novo everolimus without calcineurin inhibitor (CNI) therapy following liver transplantation was assessed in a multicenter, prospective, open-label trial. Liver transplant patients were randomized at 4 weeks to start everolimus and discontinue CNI, or continue their current CNI-based regimen. The primary endpoint was adjusted estimated GFR (eGFR; Cockcroft-Gault) at month 11 post randomization. A 24-month extension phase followed 81/114 (71.1%) of eligible patients to month 35 post randomization. The adjusted mean eGFR benefit from randomization to month 35 was 10.1 mL/min (95% confidence interval [CI] -1.3, 21.5 mL/min, p = 0.082) in favor of CNI-free versus CNI using Cockcroft-Gault, 9.4 mL/min/1.73 m(2) (95% CI -0.4, 18.9, p = 0.053) with Modification of Diet in Renal Disease (four-variable) and 9.5 mL/min/1.73 m(2) (95% CI -1.1, 17.9, p = 0.028) using Nankivell. The difference in favor of the CNI-free regimen increased gradually over time due to a small progressive decline in eGFR in the CNI cohort despite a reduction in CNI exposure. Biopsy-proven acute rejection, graft loss and death were similar between groups. Adverse events led to study drug discontinuation in five CNI-free patients and five CNI patients (12.2% vs. 12.5%, p = 1.000) during the extension phase. Everolimus-based CNI-free immunosuppression is feasible following liver transplantation and patients benefit from sustained preservation of renal function versus patients on CNI for at least 3 years.

Temporary placement of fully covered self-expandable metal stents in biliary complications after liver transplantation.

In the present study we prospectively evaluated the safety and efficacy of temporary fully covered, self-expandable metal stents (fcSEMS) to treat biliary strictures (n = 9), leaks (n = 9), and combined lesions (n = 1) occurring after liver transplantation, when standard endoscopic attempts had failed. Placement of fcSEMS and their removal in scheduled patients were successful and without complications. Resolution of the biliary lesion was confirmed in 15 of 19 patients (79 %). Treatment was not successful in two patients and not evaluable in 2 other patients. Complications occurred in 9 /19 patients (47 %): stent migration in 6, stent occlusion in 1, and de novo stricture after successful treatment of a biliary leak in 2. After a median follow-up of 12 months, one recurrent anastomotic stricture was noted. Temporary placement of fcSEMS in biliary strictures and leaks after liver transplantation provides satisfactory results even in patients who have undergone multiple previous conventional endoscopic attempts, and offers an alternative approach to surgical intervention.

In PSC with colitis treated with UDCA, most colonic carcinomas develop in the first years after the start of treatment.

BACKGROUND: Patients with PSC and IBD have a high incidence of colonic carcinomas (CRC), and the annual incidence of CRC increases with duration of disease. UDCA treatment has been suggested to reduce colonic dysplasias and carcinomas. AIMS: The annual incidence of colorectal carcinomas after long-term UDCA treatment was studied. METHODS: Patients included in a prospective study on the outcome after ursodeoxycholic acid (UDCA) treatment were evaluated. RESULTS: A total of 120 of 171 PSC patients included had IBD (108 UC and 12 CD). All patients were treated with UDCA for a median time of 6.7 years. Seven patients with PSC and IBD developed a CRC yielding a prevalence of 5.8%. In years 0-3 (n = 120) after the start of UDCA, the annual incidence rate of CRC was 0.62/100 patient years; in years 3-6 (n = 93) it increased to 1.28 and decreased thereafter in years 6-9 (n = 67) to 1.17, then in years 9-12 (n = 42) to 0 and after >12 years (n = 24) it remained 0. In PSC with IBD, Kaplan-Meier estimate of CRC formation increased with time in the first years of treatment and reached a plateau after 9 years; after treatment for ≥ 9 years, no further CRC were observed. CONCLUSION: After the start of UDCA, the annual incidence of CRC increased up to 6 years and subsequently decreased. In PSC with IBD treated with UDCA, most colonic carcinomas develop in the first years after the start of treatment.

Cytomegalovirus infection after liver transplantation incidence, risks, and benefits of prophylaxis.

BACKGROUND: Cytomegalovirus (CMV) infection and related disease is a feared complication after liver transplantation. Antiviral prophylaxis is recommended in clinical practice guidelines depending on the CMV status of both donor and recipient as well as the individual risk profile. METHODS: We retrospectively analyzed 211 liver transplant recipients with respect to the incidence of CMV infection after transplantation, the influence of donor and recipient CMV status, and the effect of antiviral prophylaxis. In addition, the underlying liver disease and immunosuppressive regimen were compared with the incidence of CMV infection. Patients were divided into 4 groups according to CMV donor/recipient (D/R) profile: group A (D-/R-) 28 patients (13.3%), group B (D-/R+) 64 patients (30.3%), group C (D+/R+) 79 patients (37.4%), and group D (D+/R-) 40 patients (19.0%). RESULTS: CMV infection was observed in 17.9%, 29.7%, 24.1%, and 22.5% of the patients, respectively, with no significant difference in infection rates between the groups. CMV infection occurred in 5 patients (17.9%) in the presumed low-risk profile (group A), despite an antiviral prophylaxis in 4 out of these 5 patients. In contrast, CMV infection occurred in only 9/40 patients (22.5%) in the presumed high-risk profile (group D). The most frequent infection rates were found in groups B and C (R+ groups). After successful treatment of CMV infection, no recurrence was detected. Underlying liver disease or immunosuppressive protocol had no influence on CMV infection. CONCLUSION: Approximately one fourth of patients will acquire CMV infection after liver transplantation independent of donor/recipient status. Surprisingly, antiviral prophylaxis does not seem to be sufficient to reduce this proportion of patients, either in presumed high-risk or in presumed low-risk situations.

Management and outcomes after multiple corneal and solid organ transplantations from a donor infected with rabies virus.

BACKGROUND: This article describes multiple transmissions of rabies via transplanted solid organ from a single infected donor. The empirical Milwaukee treatment regimen was used in the recipients. METHODS: Symptomatic patients were treated by deep sedation (ketamine, midazolam, and phenobarbital), ribavirin, interferon, and active and passive vaccination. Viral loads and antibodies were continuously monitored. RESULTS: Recipients of both cornea and liver transplants developed no symptoms. The recipient of the liver transplant had been vaccinated approximately 20 years before transplantation. Two recipients of kidney and lung transplants developed rabies and died within days of symptomatic disease. Another kidney recipient was treated 7 weeks before he died. The cerebrospinal fluid viral load remained at constant low levels (<10,000 copies/mL) for approximately 5 weeks; it increased suddenly by almost 5 orders of magnitude thereafter. After death, no virus was found in peripheral compartments (nerve tissue, heart, liver, or the small intestine) in this patient, in contrast to in patients in the same cohort who died early. CONCLUSIONS: Our report includes, to our knowledge, the longest documented treatment course of symptomatic rabies and the first time that the virus concentration was measured over time and in different body compartments. The postmortem virus concentration in the periphery was low, but there was no evidence of a reduction of virus in the brain.

An early increase in gamma glutamyltranspeptidase and low aspartate aminotransferase peak values are associated with superior outcomes after orthotopic liver transplantation.

BACKGROUND: Prediction of prognosis after liver transplantation (OLT) remains difficult. The present study determines if standard laboratory parameters measured within the first week after OLT correlate with outcome. PATIENTS AND METHODS: Laboratory parameters measured within the first weak after OLT of 328 patients were grouped either graft loss or death within 90 days after (group 1: graft loss; group 2: death; group 3: neither graft loss nor death within 90 days). RESULTS: Peak AST and ALT were significantly lower in group 3 (1867 and 1252 U/L) than in group 1 (4474 and 2077 U/L) or 2 (3121 and 1865 U/L). Bilirubin was significantly lower and gamma-GT significantly higher in group 3 compared to groups 1 and 2. In multivariate analysis, high AST peaks were independently associated with death or graft loss within 90 days. An increase in gamma-GT and low bilirubin early after transplantation were found to be independently associated with superior outcome. DISCUSSION: Unexpectedly, a disproportionate rise in gamma-GT was associated with graft and patient survival of more than 90 days. This might be explained by regeneration phenomena in the liver indicative of a well functioning graft.