A randomized double-blind comparative study of mycophenolate mofetil and azathioprine in combination with cyclosporine and corticosteroids in primary liver transplant recipients

Management of long-term complications from immunosuppression

This review discusses long-term complications from immunosuppressants after liver transplantation and the management of these complications. Common complications of calcineurin inhibitors include nephrotoxicity and metabolic diseases. Nephrotoxicity can be managed by targeting a lower drug level and/or adding an immunosuppressant of a different class. Metabolic disorders can be managed by treating the underlying condition and targeting a lower drug level. Gastrointestinal adverse effects and myelosuppression are common complications of antimetabolites that are initially managed with dose reduction or discontinuation if adverse events persist. Mammalian targets of rapamycin inhibitors are associated with myelosuppression, proteinuria, impaired wound healing, and stomatitis, which may require dose reduction or discontinuation. Induction agents and agents used for steroid-refractory rejection or antibody-mediated rejection are reviewed. Other rare complications of immunosuppressants are discussed as well.

Basics and Art of Immunosuppression in Liver Transplantation

Liver transplantation is one of the most challenging areas in the medical field. Despite that, it has already been established as a standard treatment option, especially in decompensated cirrhosis and selected cases of hepatocellular carcinoma and acute liver failure. Complications due to graft rejection, including mortality and morbidity, have greatly improved over time due to better immunosuppressive agents and management protocols. Currently, immunosuppression in liver transplant patients makes use of the best possible combinations of effective agents to achieve optimal immunosuppression for long-term graft survival. Induction agents are no longer used routinely, and the aim is to provide minimal immunosuppression in the maintenance phase. Currently available immunosuppressive agents are mainly classified as biological and pharmacological agents. Though the protocols may vary among the centers and over time, the basics of effective use usually remain similar. Most protocols use the combination of multiple agents with different mechanisms of action to reduce the dose and minimize the side effects. Along with the improvement in operative and perioperative techniques, this art of immunosuppression has contributed to the recent progress made in the outcomes of liver transplants. In this review, we will discuss the various types of immunosuppressive agents currently in use, the different protocols of immunosuppression used, and the art of optimal use for achieving maximum immunosuppression without increasing toxicity. We will also discuss the practical aspects of various immunosuppression regimens, including drug monitoring, and briefly discuss the concepts of immunosuppression minimization and withdrawal.

Asian Pacific Association for the Study of the Liver clinical practice guidelines on liver transplantation

Liver transplantation is a highly complex and challenging field of clinical practice. Although it was originally developed in western countries, it has been further advanced in Asian countries through the use of living donor liver transplantation. This method of transplantation is the only available option in many countries in the Asia-Pacific region due to the lack of deceased organ donation. As a result of this clinical situation, there is a growing need for guidelines that are specific to the Asia-Pacific region. These guidelines provide comprehensive recommendations for evidence-based management throughout the entire process of liver transplantation, covering both deceased and living donor liver transplantation. In addition, the development of these guidelines has been a collaborative effort between medical professionals from various countries in the region. This has allowed for the inclusion of diverse perspectives and experiences, leading to a more comprehensive and effective set of guidelines.

Factors associated with operational tolerance after liver transplantation: a single center retrospective study

Background

Liver transplantation has adverse effects from life-long immunosuppression that limit the improvement of long-term outcomes. Achieving clinical operational tolerance is a major goal in organ transplantation.

Methods

This study analyzed liver transplantation patients at a single institution from 1998 to 2020, excluding those who died within 1-year posttransplant. Operational tolerance was defined as normal liver function even after immunosuppressive drugs were discontinued. Propensity score matching was implemented at a 1:2 ratio for the tolerant group (TG) and the nontolerant group (NTG).

Results

Out of 2,300 recipients, 99 achieved operational tolerance without rejection. No significant differences in sex or body mass index (BMI) were found between the TG and NTG. There was a significantly higher percentage of children in the TG (24.0%) than in the NTG (10.1%). The NTG had more living donor liver transplants. Among 2,054 adult recipients, no significant differences in age, sex, or BMI were found between the TG and the NTG. However, the rate of living donor liver transplantation was 40.3% (29/75) in the TG and 84.8% in the NTG (P<0.001). The propensity score-matched analysis showed higher chronic renal failure rates and a higher graft recipient weight ratio in the TG, along with shorter warm ischemic times during surgery. After immunosuppressant withdrawal, a significant increase in the ratio of CD4+CD25+ T cells to total CD4+ T cells was observed in the TG.

Conclusions

These findings suggest that larger, healthier grafts are more conducive to inducing tolerance, and regulatory T cells are crucial in achieving tolerance.

Immunosuppressive Drugs in Liver Transplant: An Insight

Liver transplantation (LT) is the standard of care for end-stage liver failure and hepatocellular carcinoma. Over the years, immunosuppression regimens have improved, resulting in enhanced graft and patient survival. At present, the side effects of immunosuppressive agents are a significant threat to post-LT quality of life and long-term outcome. The role of personalized immunosuppression is to reach a delicate balance between optimal immunosuppression and minimal side effects. Today, immunosuppression in LT is more of an art than a science. There are no validated markers for overimmunosuppression and underimmunosuppression, only a few drugs have therapeutic drug monitoring and immunosuppression regimens vary from center to center. The immunosuppressive agents are broadly classified into biological agents and pharmacological agents. Most regimens use multiple agents with different modes of action to reduce the dosage and minimize the toxicities. The calcineurin inhibitor (CNI)-related toxicities are reduced by antibody induction or using mTOR inhibitor/antimetabolites as CNI sparing or CNI minimization strategies. Post-liver transplant immunosuppression has an intensive phase in the first three months when alloreactivity is high, followed by a maintenance phase when immunosuppression minimization protocols are implemented. Over time some patients achieve "tolerance," defined as the successful stopping of immunosuppression with good graft function and no indication of rejection. Cell-based therapy using immune cells with tolerogenic potential is the future and may permit complete withdrawal of immunosuppressive agents.

The optimal immunosuppression management to prevent early rejection after liver transplantation: A systematic review of the literature and expert panel recommendations

BACKGROUND

The optimal immunosuppression protocol to prevent early acute cellular rejection (ACR) after liver transplantation (LT) avoiding prolonged hospitalization and early hospital readmission is undefined.

OBJECTIVES

To identify the most suitable immunosuppression regimen for inclusion in ERAS programs in order to minimize early ACR after LT and to provide expert panel recommendations DATA SOURCES: Ovid MEDLINE, Embase, Scopus, Google Scholar, and Cochrane Central.

METHODS

Systematic review following PRISMA guidelines and recommendations using the GRADE approach derived from an international expert panel. Studies from January 2000 onward focusing on early ACR were included. Rates of early renal dysfunction and infection were evaluated. CRD42021245586 RESULTS: Thirty-seven studies met inclusion criteria; 23 randomized controlled trials, 14 retrospective or prospective observational comparative or noncomparative studies. Several sources of biases which potentially confound conclusions were identified: heterogeneity in immunosuppression protocols, higher serum tacrolimus levels than currently used in clinical practice, differences in the definition of ACR.

CONCLUSIONS

Tacrolimus is the standard immunosuppression after LT and can be used in combination with other drugs such as corticosteroids and MMF, and in association with anti-IL2 receptor antibody (IL2Ra) induction. (Quality of Evidence; Low | Grade of Recommendation; Strong). Low dose or delayed introduction of tacrolimus in association with corticosteroids and MMF and/or anti-IL2Ra induction can be used to reduce acute kidney injury. (Quality of Evidence; Low | Grade of Recommendation; Strong). Use of tacrolimus in association with corticosteroids and MMF and/or anti-IL2Ra induction does not lead to increased infection rates. (Quality of Evidence; Low | Grade of Recommendation; Weak).

[Update: Immunosuppression in organ transplantation]

Immunosuppression is an essential prerequisite for successful transplantation. In order to reduce the sometimes-considerable side effects, combination therapies with different agents are used. This article aims to provide an up-to-date overview of immunosuppression after liver and kidney transplantation.

The Molecular Quality and Mitochondrial Activity of Porcine Cumulus-Oocyte Complexes Are Affected by Their Exposure to Three Endocrine-Active Compounds under 3D In Vitro Maturation Conditions

Thus far, the potential short- and long-term detrimental effects of a variety of environmental chemicals designated as endocrine-active compounds (EACs) have been found to interfere with histo- and anatomo-physiological functions of the reproductive system in humans and wildlife species. For those reasons, this study sought to examine whether selected EACs, which encompass the fungicide vinclozolin (Vnz), the androgenic anabolic steroid nandrolone (Ndn) and the immunosuppressant cyclosporin A (CsA), affect the developmental competence and molecular quality (MQ) of porcine cumulus–oocyte complexes (COCs) subjected to in vitro maturation (IVM) under 3D culture conditions. The COCs underwent 3D-IVM in the presence of Vnz, Ndn or CsA for 48 h. To explore whether the selected EACs induce internucleosomal DNA fragmentation in cumulus cells (CCs), TUNEL-assisted detection of late apoptotic cells was performed. Additionally, for the detailed evaluation of pro- and antiapoptotic pathways in COCs, apoptosis proteome profiler arrays were used. To determine changes in intracellular metabolism in COCs, comprehensive assessments of mitochondrial ultrastructure and activity were carried out. Moreover, the relative abundances (RAs) of mRNAs transcribed from genes that are involved in scavenging reactive oxygen species (ROS), such as SIRT3 and FOXO3, and intramitochondrial bioenergetic balance, such as ATP synthase subunit (ATP5A1), were ascertained. Finally, to investigate the extent of progression of oocyte maturation, the intraooplasmic levels of cAMP and the RAs of mRNA transcripts encoding regulatory and biocatalytic subunits of a heterodimeric meiosis-promoting factor, termed cyclin B1 (CCNB1) and cyclin-dependent kinase 1 (CDC2), were also estimated. The obtained results provide, for the first time, strong evidence that both Vnz and Ndn decrease the developmental competence of oocytes and stimulate apoptosis processes in CCs. The present study is also the first to highlight that Vnz accelerates the maturation process in immature oocytes due to both increased ROS production and the augmented RA of the CCNB1 gene. Furthermore, Vnz was proven to trigger proapoptotic events in CCs by prompting the activity of the FOXO3 transcription factor, which regulates the mitochondrial apoptosis pathway. In turn, Ndn was shown to inhibit oocyte maturation by inducing molecular events that ultimately lead to an increase in the intraooplasmic cAMP concentration. However, due to the simultaneous enhancement of the expression of TNF-β and HSP27 proteins in CCs, Ndn might be responsible for the onset of their neoplastic transformation. Finally, our current investigation is the first to clearly demonstrate that although CsA did not interfere with the nuclear and cytoplasmic maturation of oocytes, by inducing mitophagy in CCs, it disrupted oocyte metabolism, consequently attenuating the parameters related to the MQ of COCs. Summing up, Vnz, Ndn and CsA reduced not only the processes of growth and IVM but also the MQ of porcine COCs, which might make them unsuitable for assisted reproductive technologies (ARTs) such as in vitro fertilization by either gamete co-incubation or intracytoplasmic sperm injection (ICSI) and cloning by somatic cell nuclear transfer (SCNT).

Differential IgG4-Producing Plasma Cell Infiltration in Non- and Post-Transplant Plasma Cell Hepatitis

Autoimmune hepatitis (AIH), post-transplant recurrent AIH (rAIH), and plasma cell-rich rejection (PCR) are clinical diagnoses with the shared histopathologic hallmark of plasma cell hepatitis (PCH). As these histologically and serologically indistinguishable diagnoses are differentiated by clinical context, it remains uncertain whether they represent distinct immunologic phenomena. Improved understanding of immunoglobulin subclass 4-producing plasma cells (IgG4-PC) has brought attention to IgG4 as an immunophenotypic biomarker. To date, degree and clinical significance of IgG4-PC infiltration in PCH remain elusive. This retrospective, single-center study assessed IgG4-PC infiltration in AIH, rAIH, and PCR via standardized immunohistochemistry analysis. Identified cases from 2005 to 2020 (n = 47) included AIH (treatment-naïve AIH (tnAIH): n = 15 and AIH-flare on treatment (fAIH); n = 10), rAIH (n = 8), and PCR (n = 14) were analyzed and correlated with clinical characteristics. IgG4-Positivity (# IgG4-PC/# pan-IgG-expressing cells) distribution was heterogenous and overlapping [tnAIH: 0.060 (IQR 0.040-0.079), fAIH: 0.000 (0.000-0.033), rAIH: 0.000 (0.000-0.035), PCR: 0.228 (0.039-0.558)]. IgG4-Positivity was inversely correlated with corticosteroid use (p < 0.001). IgG4-Positivity ≥0.500 was associated with rapid AST improvement (p = 0.03). The variable IgG4-Positivity of AIH, rAIH and PCR suggests diverse and overlapping immunopathologic mechanisms and that current diagnostic schemes inadequately capture PCH immunopathology. We propose incorporation of IgG4-Positivity to refine current PCH classification and treatment strategies.

No Influence of Everolimus on Mycophenolic Acid Area Under the Concentration-Time Curve: Limited Sampling Strategy for Mycophenolic Acid in Japanese Kidney Transplant Recipients Treated With Tacrolimus, Mycophenolate Mofetil, Steroid, and Everolimus

BACKGROUND

Despite a growing need for everolimus (EVR) to reduce calcineurin inhibitor toxicity in kidney transplantation (KTx), the influence of EVR on the pharmacokinetics of mycophenolic acid (MPA), a mycophenolate mofetil (MMF) active metabolite, is obscure, and no suitable limited sampling strategy (LSS) for MPA when EVR is concomitantly present exists. We aimed to investigate the influence of EVR on MPA pharmacokinetics in KTx.

MATERIALS AND METHODS

This study complied with all principles of the Declaration of Helsinki. Twenty patients were initially administered tacrolimus, MMF, and methylprednisolone and then received EVR 4 months after KTx. Approximately 4 weeks before and after EVR administration, the estimated value of the area under the concentration-time curve for MPA from 0 to 12 hours (MPA-AUC0-12) was calculated using MPA blood concentration just before and 1, 2, 4, and 6 hours after MMF administration. We compared several MPA pharmacokinetics parameters before and after EVR addition and determined the best estimation equation for LSS of MPA-AUC0-12.

RESULTS

Although MPA-C6 per dose (MPA-C6/D) significantly decreased after EVR addition (from 3.4 [±2.2] ng/mL/g to 2.5 [±0.9] ng/mL/g), MPA-C0/D, -C1/D, -C2/D, -C4/D, and MPA-AUC0-12/D showed no significant change. MPA-AUC0-12/D did not correlate with EVR-AUC0-12/D. The best estimation equation for LSS of MPA-AUC0-12 by 2 time points was [(2.94 × C2) + (5.09 × C4) + 5.32] (R² = 0.73) and [(5.70 × C0) + (1.39 × C1) + 22.45] (R² = 0.72) before and after EVR addition, respectively.

CONCLUSIONS

EVR can be safely combined with MMF after KTx once our results have been reevaluated.

A single-center, open-label, randomized cross-over study to evaluate the pharmacokinetics and bioavailability of once-daily prolonged-release formulations of tacrolimus in de novo liver transplant recipients

BACKGROUND

The narrow therapeutic window of tacrolimus (Tac) requires intense drug monitoring to achieve adequate efficacy while minimizing dose-related toxicities. Once-daily formulations of Tac (LCP-Tac and PR-Tac) have been recently designed for higher bioavailability and a more consistent exposure over time, as opposed to the twice-daily, administered immediate-release formulation of Tac (IR-Tac).

METHODS

This single-center, open-label, randomized cross-over pharmacokinetic (PK) study compares extended-release LCP-Tac with the prolonged-release formulation of tacrolimus (PR-Tac) in adult de novo liver transplant recipients. Eligible patients were screened and randomized 1:1 to the two treatment arms up to 30 days after liver transplantation. Patients were administered either LCP-Tac or PR-Tac for 14 days followed by another 14-day time interval of the other once-daily Tac medication. A 24hr-PK profile was obtained at the end of each time interval.

RESULTS

Nine patients (45%) completed the study resulting in a total of 18 Tac PK profiles. Overall, the profile of the mean concentrations indicated a flattened kinetic of LCP-Tac compared to PR-Tac, especially in the first 3 h after drug intake. The average cumulative dose per day to achieve equivalent trough levels was approximately 25% lower for LCP-Tac (8.7 mg) than for PR-Tac (11.7 mg). LCP-Tac resulted in a longer tmax and fewer peak-to-trough fluctuations compared to PR-Tac.

CONCLUSION

Despite methodological weaknesses that limit the conclusions, we have found a more consistent drug exposure for LCP-Tac in de novo LT recipients. LCP-Tac demonstrated a greater bioavailability compared to PR-Tac.

Antiproliferatives and Transplantation

Antiproliferative agents include Mycophenolic acid and Azathioprine (which is less commonly used unless in certain conditions). They were initially identified for use in autoimmune and cancer research due to their role in disruption of cellular replication. They have now become the cornerstone of antirejection maintenance therapy in solid organ transplant. In this chapter we will describe the major times that lead to discovery, mechanisms of action, side effects, use during pregnancy and the major clinical trials.

Immunosuppression in liver and intestinal transplantation

Immunosuppression handling plays a key role in the early and long-term results of transplantation. The development of multiple immunosuppressive drugs led to numerous clincial trials searching to reach the ideal regimen. Due to heterogeneity of the studied patient cohorts and flaws in many, even randomized controlled, study designs, the answer still stands out. Nowadays triple-drug immunosuppression containing a calcineurin inhibitor (preferentially tacrolimus), an antimetabolite (using mycophenolate moffettil or Azathioprine) and short-term steroids with or without induction therapy (using anti-IL2 receptor blocker or anti-lymphocytic serum) is the preferred option in both liver and intestinal transplantation. This chapter aims, based on a critical review of the definitions of rejection, corticoresistant rejection and standard immunosuppression to give some reflections on how to reach an optimal immunosuppressive status and to conduct trials allowing to draw solid conclusions. Endpoints of future trials should not anymore focus on biopsy proven, acute and chronic, rejection but also on graft and patient survival. Correlation between early- and long-term biologic, immunologic and histopathologic findings will be fundamental to reach in much more patients the status of operational tolerance.

Therapeutic drug monitoring of immunosuppressive drugs in hepatology and gastroenterology

Immunosuppressive drugs have been key to the success of liver transplantation and are essential components of the treatment of inflammatory bowel disease (IBD) and autoimmune hepatitis (AIH). For many but not all immunosuppressants, therapeutic drug monitoring (TDM) is recommended to guide therapy. In this article, the rationale and evidence for TDM of tacrolimus, mycophenolic acid, the mammalian target of rapamycin inhibitors, and azathioprine in liver transplantation, IBD, and AIH is reviewed. New developments, including algorithm-based/computer-assisted immunosuppressant dosing, measurement of immunosuppressants in alternative matrices for whole blood, and pharmacodynamic monitoring of these agents is discussed. It is expected that these novel techniques will be incorporate into the standard TDM in the next few years.

Randomized trial of steroid free immunosuppression with basiliximab induction in adult live donor liver transplantation (LDLT)

BACKGROUND

Corticosteroids are an integral part of immunosuppression following solid organ transplantation, despite their metabolic complications. We conducted a randomized trial to evaluate the efficacy of steroid-free immunosuppression following live donor liver transplantation (LDLT).

METHODS

We randomized 104 patients stratified based on pre-transplant diabetic status to either a steroid-free arm (SF-arm) (Basiliximab + Tacrolimus and Azathioprine,n = 52) or Steroid arm (S-Arm) (Steroid + Tacrolimus + Azathioprine,n = 52). The primary endpoint was the occurrence of metabolic complications (new-onset diabetes after transplant (NODAT), new-onset systemic hypertension after transplant (NOSHT), post-transplant dyslipidemia) within 6 months after transplant. Secondary endpoints included biopsy-proven acute rejection (BPAR) within six months, patient and graft survival at 6 months.

RESULTS

The incidence NODAT was significantly higher in S-arm at 3 months (64.5%vs. 28.1%,p-0.004) and 6 months (51.6% vs. 15.6%,p-0.006). Likewise, the incidence of NOSHT (27.8% vs. 4.8%,p-0.01) and hypertriglyceridemia (26.7% vs. 8%,p-0.03) at six months was significantly higher in S-arm. However, there were no differences in BPAR (19.2% vs. 21.2%, p-0.81), time to first rejection (58 vs. 53 days, p-0.78), patient and graft survival (610 vs. 554 days,p- 0.22).

CONCLUSION

Following LDLT, basiliximab induction with tacrolimus and azathioprine maintenance resulted in significantly lower metabolic complications compared to the triple-drug regimen of steroid, tacrolimus, and azathioprine.

Diarrhea in the pediatric solid organ transplantation recipient: A multidisciplinary approach to diagnosis and management

Diarrhea in the pediatric solid organ transplantation (SOT) recipient is a frequent complaint that is associated with significant morbidity and impaired quality of life. There are limited published data regarding the specific epidemiology, diagnostic evaluation, and treatment of diarrhea after SOT in children. Pediatric SOT recipients have an increased risk of developing diarrhea because of a generalized immunosuppressed state, epidemiologic exposures, and polypharmacy. There is a need to standardize the diagnostic evaluation of diarrhea in children after SOT to facilitate an accurate diagnosis and timely treatment. Herein, we review the available published data and propose a systematic, stepwise approach to the evaluation of diarrhea in this high-risk population, focusing on timely diagnosis of both infectious and non-infectious causes, in order to provide focused management. Prospective studies are needed to better assess the true prevalence, risk factors for, etiologies, and complications of diarrhea in pediatric SOT patients that will guide optimal management. Development of effective vaccines and antiviral therapies for enteric viruses may also contribute to improved outcomes.

Update: Immunsuppression bei Organtransplantationen

Die Immunsuppression ist eine wesentliche Grundvoraussetzung für eine erfolgreiche Transplantation. Zur Reduktion der teils beträchtlichen Nebenwirkungen werden Kombinationstherapien mit unterschiedlichen Wirkstoffen durchgeführt. Dieser Beitrag soll einen aktuellen Überblick zur Immunsuppression nach Leber- und Nierentransplantation geben.

Therapeutic potential and molecular mechanisms of mycophenolic acid as an anticancer agent

Mycophenolic acid (MPA) is the active metabolite of mycophenolate mofetil (MMF), an immunosuppressive drug approved for the prophylaxis of allograft rejection in transplant recipients. Recent advances in the role of the type II isoform of inosine-5'-monophosphate dehydrogenase (IMPDH2) in the tumorigenesis of various types of cancer have called for a second look of MPA, the first IMPDH2 inhibitor discovered a hundred years ago, to be repurposed as an anticancer agent. Over a half century, a number of in vitro and in vivo experiments have consistently shown anticancer activity of MPA against several cell lines obtained from different malignancies and murine models. However, a few clinical trials have been conducted to investigate its anticancer activity in humans, and most of which have shown unsatisfactory results. Understanding of available evidence and underlying mechanism of action is a key step to be done so as to facilitate further investigations of MPA to reach its full therapeutic potential as an anticancer agent. This article provides a comprehensive review of non-clinical and clinical evidence available to date, with the emphasis on the molecular mechanism of action in which MPA exerts its anticancer activities: induction of apoptosis, induction of cell cycle arrest, and alteration of tumor microenvironment. Future perspective for further development of MPA to be an anticancer agent is extensively discussed, with the aim of translating the anticancer property of MPA from bench to bedside.

Serum Trough Concentration and Effects of Mycophenolate Mofetil Based on Pathologic Findings in Infants After Liver Transplantation

OBJECTIVES

Mycophenolate mofetil (MMF) is mainly used in conjunction with calcineurin inhibitors as an additional immunosuppressive for renal sparing after liver transplantation. However, few reports about MMF use in infants after living donor liver transplantation (LDLT) are available. The purpose of this study was to examine the efficacy and safety of MMF in infants.

METHODS

This study enrolled infants younger than 1 year of age who received LDLT at our institution. Patients received oral MMF twice daily. The initial dose was 40 to 50 mg/kg/d, which was increased to a target mycophenolic acid (MPA) trough level of 2 mg/L. Body weight, height, MMF dose, MPA trough level, acute cellular rejection (ACR) episodes, pathologic findings, and adverse effects were analyzed. Allograft fibrosis was graded using the Meta-analysis of Histological Data in Viral Hepatitis score.

RESULTS

Patients received MMF for refractory ACR (n = 2), fulminant hepatitis (n = 2), and pre-existing antibodies (n = 1). Original diseases were biliary atresia (n = 3) and fulminant hepatitis (n = 2). Mean age at transplant was 8 months (range 3-10 months). The last available mean trough level was 2.7 mg/L. The mean dose was 66 mg/kg/d or 1429 mg/m²/d at the time of the last available through level. The regression line for MMF dose and MPA trough level was y = 1.8 × 10^-3x. The correlation coefficient was 0.65. All allografts showed F1 to F2 fibrosis. Two patients discontinued MMF because of infection and bone marrow suppression, respectively. Two patients converted to everolimus. One patient continued on MMF.

CONCLUSIONS

After LDLT, infants require a higher MMF dose than older patients based on trough levels, but allograft fibrosis can progress.

Serp-2, a virus-derived apoptosis and inflammasome inhibitor, attenuates liver ischemia-reperfusion injury in mice

BACKGROUND

Ischemia-reperfusion injury (IRI) is an antigen-independent, innate immune response to arterial occlusion and ischemia with subsequent paradoxical exacerbation after reperfusion. IRI remains a critical problem after vessel occlusion and infarction or during harvest and surgery in transplants. After transplant, liver IRI (LIRI) contributes to increased acute and chronic rejection and graft loss. Tissue loss during LIRI has been attributed to local macrophage activation and invasion with excessive inflammation together with hepatocyte apoptosis and necrosis. Inflammatory and apoptotic signaling are key targets for reducing post-ischemic liver injury.Myxomavirus is a rabbit-specific leporipoxvirus that encodes a suite of immune suppressing proteins, often with extensive function in other mammalian species. Serp-2 is a cross-class serine protease inhibitor (serpin) which inhibits the inflammasome effector protease caspase-1 as well as the apoptotic proteases granzyme B and caspases 8 and 10. In prior work, Serp-2 reduced inflammatory cell invasion after angioplasty injury and after aortic transplantation in rodents. In this report, we explore the potential for therapeutic treatment with Serp-2 in a mouse model of LIRI.

METHODS

Wildtype (C57BL/6 J) mice were subjected to warm, partial (70%) hepatic ischemia for 90 min followed by treatment with saline or Serp-2 or M-T7, 100 ng/g/day given by intraperitoneal injection on alternate days for 5 days. M-T7 is a Myxomavirus-derived inhibitor of chemokine-GAG interactions and was used in this study for comparative analysis of an unrelated viral protein with an alternative immunomodulating mechanism of action. Survival, serum ALT levels and histopathology were assessed 24 h and 10 days post-LIRI.

RESULTS

Serp-2 treatment significantly improved survival to 85.7% percent versus saline-treated wildtype mice (p = 0.0135), while M-T7 treatment did not significantly improve survival (p = 0.2584). Liver viability was preserved by Serp-2 treatment with a significant reduction in serum ALT levels (p = 0.0343) and infarct scar thickness (p = 0.0016), but with no significant improvement with M-T7 treatment. Suzuki scoring by pathologists blinded with respect to treatment group indicated that Serp-2 significantly reduced hepatocyte necrosis (p = 0.0057) and improved overall pathology score (p = 0.0046) compared to saline. Immunohistochemistry revealed that Serp-2 treatment reduced macrophage infiltration into the infarcted liver tissue (p = 0.0197).

CONCLUSIONS

Treatment with Serp-2, a virus-derived inflammasome and apoptotic pathway inhibitor, improves survival after liver ischemia-reperfusion injury in mouse models. Treatment with a cross-class immune modulator provides a promising new approach designed to reduce ischemia-reperfusion injury, improving survival and reducing chronic transplant damage.

National Trends in Liver Transplantation in Older Adults

OBJECTIVES

To explore trends in liver transplantation (LT) and outcomes for older recipients for evaluation, counseling, and appropriate referral of this vulnerable group of older adults.

DESIGN

Prospective national cohort study.

SETTING

Scientific Registry of Transplant Recipients (January 1, 2003-December 31, 2016).

PARTICIPANTS

Older (aged ≥ 65) deceased donor liver-only transplant recipients (n=8,627).

MEASUREMENTS

We evaluated temporal changes in recipient, donor, and transplant characteristics and post-LT length of stay (LOS), acute rejection, graft loss, and mortality using logistic regression and Cox proportional hazards.

RESULTS

LT in older adults almost quadrupled, from 263 in 2003 (9.5% of total LTs that year) to 1,144 in 2016 (20.7% of total LTs). Recent recipients were more likely to be female and African American and have a higher body mass index and Model for End-Stage Liver Disease score. Hepatitis C, nonalcoholic steatohepatitis, and hepatocellular carcinoma were the most common indications for LT in recent recipients. Odds of LOS longer than 2 weeks decreased 34% from 2003-06 to 2013-16 (adjusted odds ratio (aOR)=0.66, 95% confidence interval (CI)=0.57-0.76, P < .001), 1-year acute rejection decreased 30% (aOR=0.70, 95% CI=0.56-0.88, P = .002), all-cause graft loss decreased 54% (adjusted hazard ratio (aHR)=0.46, 95% CI=0.40-0.52, P < .001), and mortality decreased 57% (aHR=0.43, 95% CI=0.38-0.49, P < .001).

CONCLUSION

Despite the substantial increase in the number of older adults undergoing LT and the severity of their condition, LOS, rejection, graft loss, and mortality have significantly decreased over time. These trends can help guide appropriate LT referral and counseling in older adults with end-stage liver disease. J Am Geriatr Soc 66:2321-2326, 2018.

Interaction of immunosuppressants with HCV antivirals daclatasvir and asunaprevir: combined effects with mycophenolic acid

AIM

To investigate the specific effects of immunosuppressants on the antiviral action of daclatasvir and asunaprevir.

METHODS

The antiviral activity of daclatasvir (DCV) and asunaprevir (ASV) combined with immunosuppressants was tested using two in vitro models for hepatitis C virus (HCV) infection.

RESULTS

Tacrolimus, rapamycin and cyclosporine did not negatively affect the antiviral action of DCV or ASV. Mycophenolic acid (MPA) showed additive antiviral effects combined with these direct acting antivirals (DAAs). MPA induces interferon-stimulated genes (ISGs) and is a potent GTP synthesis inhibitor. DCV or ASV did not induce ISGs expression nor affected ISG induction by MPA. Rather, the combined antiviral effect of MPA with DCV and ASV was partly mediated via inhibition of GTP synthesis.

CONCLUSION

Immunosuppressants do not negatively affect the antiviral activity of DAAs. MPA has additive effect on the antiviral action of DCV and ASV. This combined benefit needs to be confirmed in prospective clinical trials.

Immunosuppression for Lung Transplantation: Current and Future

Purpose of the review

The number of lung transplantations performed worldwide continues to increase. There is a growing need in these patients for more effective immunosuppressive medications with less toxicity.

Recent findings

This review article summarizes the recent studies and developments in lung transplant immunosuppression. Novel immunosuppressive medications and strategies used in other solid organ transplantations are being trialed in lung transplantation. This includes the use of co-stimulation blockers like belatacept and mTOR inhibitors like everolimus. Calcineurin sparing regimens have been described in an attempt to minimize nephrotoxicity. Assays to measure the bioactivity of immunosuppressive medications to determine the global immune competence, such as Immuknow assay and Gamma interferon response are gaining traction.

Summary

Immunosuppression in lung transplant is evolving with the development of newer drugs and promising strategies to optimize immunosuppression. Further studies with multicenter randomized trials are required to increase the strength of the evidence.

New frontiers in immunosuppression

Immunosuppressive therapy is arguably the most important component of medical care after lung transplantation. The goal of immunosuppression is to prevent acute and chronic rejection while maximizing patient survival and long-term allograft function. However, the benefits of immunosuppressive therapy must be balanced against the side effects and major toxicities of these medications. Immunosuppressive agents can be classified as induction agents, maintenance therapies, treatments for acute rejection and chronic rejection and antibody directed therapies. Although induction therapy remains an area of controversy in lung transplantation, it is still used in the majority of transplant centers. On the other hand, maintenance immunosuppression is less contentious; but, unfortunately, since the creation of three-drug combination therapy, including a glucocorticoid, calcineurin inhibitor and anti-metabolite, there have been relatively modest improvements in chronic maintenance immunosuppressive regimens. The presence of HLA antibodies in transplant candidates and development of de novo antibodies after transplantation remain a major therapeutic challenge before and after lung transplantation. In this chapter we review the medications used for induction and maintenance immunosuppression along with their efficacy and side effect profiles. We also review strategies and evidence for HLA desensitization prior to lung transplantation and management of de novo antibody formation after transplant. Finally, we review immune tolerance and the future of lung transplantation to limit the toxicities of conventional immunosuppressive therapy.

Usefulness of limited sampling strategy for mycophenolic acid area under the curve considering postoperative days in living-donor renal transplant recipients with concomitant prolonged-release tacrolimus

Background

The optimal dose of mycophenolate mofetil (MMF) in renal transplant patients has been recommended to be decided on the basis of area under the concentration-time curve (AUC_0-12) of mycophenolic acid (MPA). Although meta-analysis has revealed that postoperative day (POD) is an influencing factor in MPA pharmacokinetics, there are no reports regarding a limited sampling strategy (LSS) for MPA AUC in consideration of POD. The aim of this study was to construct of an LSS considering POD that appropriately expresses the MPA AUC following renal transplantation and evaluation of the usefulness.

Methods

Serum concentration–time profiles (measured AUC_0-12) comprising nine sampling points over 12 h were analyzed in 36 living-donor renal transplant recipients after MMF administration with concomitant once-daily prolonged-release tacrolimus. Two LSSs were developed by stepwise multiple regression analysis (Method A: not classified by PODs; Method B: classified by PODs into POD < 31 and POD ≥ 31). Each LSS comprised four blood-sampling points within 6 h after MMF administration. Precision and reliability were verified by using root-mean-square error (RMSE), correlation coefficient (R²), and coefficient of determination (q²) by using leave-one-out cross-validation. The absolute values of the difference between measured and estimated AUCs (delta AUC) were compared for both estimating equations.

Results

One-hundred samples obtained from 36 recipients for AUC_0-12 comprised POD < 31 (n = 39) and POD ≥ 31 (n = 61). Estimation of AUC_0-12 by Method B resulted in better accuracy and reliability (Method A: RMSE = 5.5, R² = 0.85, q² = 0.83; Method B: POD < 31: RMSE = 5.5, R² = 0.86, q² = 0.83; POD ≥ 31: RMSE = 3.9, R² = 0.92, q² = 0.89) and significantly lower median delta AUC compared with that by Method A (delta AUC: 2.6 (0.0–11.6) v.s. 3.9 (0.1–18.1), p = 0.032).

Conclusion

These results suggest that LSS, classified as POD < 31 or POD > 31, would provide more accurate and reliable estimation of MPA AUC_0-12 in Japanese living-donor renal transplant patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s40780-017-0086-7) contains supplementary material, which is available to authorized users.

Inflammatory bowel disease in liver transplanted patients

Most common hepatobiliary manifestation of inflammatory bowel disease (IBD) are primary sclerosing cholangitis (PSC) and autoimmune hepatitis, ranking them as the main cause of liver transplantation (LT) in IBD setting. Course of pre-existing IBD after LT differs depending on many transplant related factors. Potential risk factors related to IBD deterioration after LT are tacrolimus-based immunosuppressive regimens, active IBD and cessation of 5-aminosalicylates at the time of LT. About 30% patients experience improvement of IBD after LT, while approximately the same percentage of patients worsens. Occurrence of de novo IBD may develop in 14%-30% of patients with PSC. Recommended IBD therapy after LT is equivalent to recommendations to overall IBD patients. Anti-tumor necrosis factor alpha appears to be efficient for refractory IBD. Due to potential side effects it needs to be applied with caution. In average 9% of patients require proctocolectomy due to medically refractory IBD or colorectal carcinoma. The most frequent complication in patients who undergo proctocolectomy with ileal-pouch anal anastomosis is pouchitis. It is still undeterminable if LT adds to risk of developing pouchitis in PSC patients. Annual colonoscopies are recommended as surveillance and precaution of colonic malignancies.

Maintenance immunosuppression for adults undergoing liver transplantation: a network meta-analysis

BACKGROUND

As part of liver transplantation, immunosuppression (suppressing the host immunity) is given to prevent graft rejections resulting from the immune response of the body against transplanted organ or tissues from a different person whose tissue antigens are not compatible with those of the recipient. The optimal maintenance immunosuppressive regimen after liver transplantation remains uncertain.

OBJECTIVES

To assess the comparative benefits and harms of different maintenance immunosuppressive regimens in adults undergoing liver transplantation through a network meta-analysis and to generate rankings of the different immunosuppressive regimens according to their safety and efficacy.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, Science Citation Index Expanded, World Health Organization International Clinical Trials Registry Platform, and trials registers until October 2016 to identify randomised clinical trials on immunosuppression for liver transplantation.

SELECTION CRITERIA

We included only randomised clinical trials (irrespective of language, blinding, or publication status) in adult participants undergoing liver transplantation (or liver retransplantation) for any reason. We excluded trials in which participants had undergone multivisceral transplantation or participants with established graft rejections. We considered any of the various maintenance immunosuppressive regimens compared with each other.

DATA COLLECTION AND ANALYSIS

We performed a network meta-analysis with OpenBUGS using Bayesian methods and calculated the odds ratio, rate ratio, and hazard ratio (HR) with 95% credible intervals (CrI) based on an available-case analysis, according to National Institute of Health and Care Excellence Decision Support Unit guidance.

MAIN RESULTS

We included a total of 26 trials (3842 participants) in the review, and 23 trials (3693 participants) were included in one or more outcomes in the review. The vast majority of the participants underwent primary liver transplantation. All of the trials were at high risk of bias, and all of the evidence was of low or very low quality. In addition, because of sparse data involving trials at high risk of bias, it is not possible to entirely rely on the results of the network meta-analysis. The trials included mainly participants undergoing primary liver transplantation of varied aetiologies. The follow-up in the trials ranged from 3 to 144 months. The most common maintenance immunosuppression used as a control was tacrolimus. There was no evidence of difference in mortality (21 trials; 3492 participants) or graft loss (15 trials; 2961 participants) at maximal follow-up between the different maintenance immunosuppressive regimens based on the network meta-analysis. In the direct comparison, based on a single trial including 222 participants, tacrolimus plus sirolimus had increased mortality (HR 2.76, 95% CrI 1.30 to 6.69) and graft loss (HR 2.34, 95% CrI 1.28 to 4.61) at maximal follow-up compared with tacrolimus. There was no evidence of differences in the proportion of people with serious adverse events (1 trial; 719 participants), proportion of people with any adverse events (2 trials; 940 participants), renal impairment (8 trials; 2233 participants), chronic kidney disease (1 trial; 100 participants), graft rejections (any) (16 trials; 2726 participants), and graft rejections requiring treatment (5 trials; 1025 participants) between the different immunosuppressive regimens. The network meta-analysis showed that the number of adverse events was lower with cyclosporine A than with many other immunosuppressive regimens (12 trials; 1748 participants), and the risk of retransplantation (13 trials; 1994 participants) was higher with cyclosporine A than with tacrolimus (HR 3.08, 95% CrI 1.13 to 9.90). None of the trials reported number of serious adverse events, health-related quality of life, or costs.

FUNDING

14 trials were funded by pharmaceutical companies who would benefit from the results of the trial; two trials were funded by parties who had no vested interest in the results of the trial; and 10 trials did not report the source of funding.

AUTHORS' CONCLUSIONS

Based on low-quality evidence from a single small trial from direct comparison, tacrolimus plus sirolimus increases mortality and graft loss at maximal follow-up compared with tacrolimus. Based on very low-quality evidence from network meta-analysis, we found no evidence of difference between different immunosuppressive regimens. We found very low-quality evidence from network meta-analysis and low-quality evidence from direct comparison that cyclosporine A causes more retransplantation compared with tacrolimus. Future randomised clinical trials should be adequately powered; performed in people who are generally seen in the clinic rather than in highly selected participants; employ blinding; avoid postrandomisation dropouts or planned cross-overs; and use clinically important outcomes such as mortality, graft loss, renal impairment, chronic kidney disease, and retransplantation. Such trials should use tacrolimus as one of the control groups. Moreover, such trials ought to be designed in such a way as to ensure low risk of bias and low risks of random errors.

Adverse symptoms of immunosuppressants: A survey of Canadian transplant clinicians

Adverse symptoms of immunosuppressants (ASI) impact quality of life (QOL) in solid organ transplant recipients; however, standardized approaches for active ASI surveillance and intervention are lacking. While management is highly clinician dependent, clinician views remain largely unexplored. We surveyed Canadian Society of Transplantation members on their perceptions of ASI including frequency, perceived QOL impact, causal attribution, management strategies, and success. Sixty-one clinicians participated in the survey of 12 ASI (tremor, diarrhea, nausea, constipation, dyspepsia, insomnia, edema, dyspnea, arthralgia, acne, mouth sores, paresthesias), for a 22% response rate. Forty-nine completed the survey (80% completion rate). Diarrhea, dyspepsia, and insomnia were most frequent, requiring management in ≥ 2% of patients by 96%, 90%, and 82% of respondents, respectively. Diarrhea, insomnia, and dyspnea were deemed to have an important QOL impact by 92%, 82%, and 69%. Immunosuppressants were universally implicated as causative of tremor, diarrhea, acne, and mouth sores. Over 80% reported success in managing mouth sores, dyspepsia, and constipation. Management strategies included adjustment of immunosuppressant or other medications, drug therapy, and nonpharmacologic approaches and varied according to perceived causal attribution. More study is needed to compare clinician and patient views. These results will be used to establish priorities for further investigation of ASI.

Systemic Immunomodulatory Strategies in High-risk Corneal Transplantation

The cornea is the most commonly transplanted tissue in the body. Although corneal grafts generally have high success rates, transplantation onto inflamed and vascularized host beds, or so-called high-risk corneal transplantation, has a high rate of graft rejection. The management of this high-risk corneal transplantation is challenging and involves numerous measures. One of the key measures to prevent graft rejection in these cases is the use of systemic immunosuppressive agents. In this article, we will review the systemic immunosuppressive agents most commonly used for high-risk corneal transplantation, which include corticosteroids, cysclosporine A, tacrolimus, mycophenolate mofetil, and rapamycin. Benefits, risks, and published data on the use of these medications for high-risk corneal transplantation will be detailed. We will also summarize novel immunoregulatory approaches that may be used to prevent graft rejection in high-risk corneal transplantation.

Mycophenolate mofetil in patients with hepatitis C virus infection

Diagnosis and treatment of hepatitis C virus (HCV) -related autoimmune features has become a clinical challenge in HCV-infected patients, in whom chronic liver disease associated with severe autoimmune features may contribute to a very poor prognosis. Both antiviral and immunosuppressive therapies, either alone or in combination, seem likely to have a key role. Based on the experience of mycophenolate mofetil (MMF) use in HCV patients receiving organ transplantation, this new immunosuppressive agent might represent a safe and effective therapeutic option to treat HCV-related extrahepatic features. Recent data are available for the use of MMF in HCV patients with autoimmune manifestations, mainly for autoimmune cytopenias and vasculitic features. MMF may be used as monotherapy or in association with other drugs for cases of HCV-related autoimmune diseases refractory or intolerant to common immunosuppressive treatments, allowing the reduction of the drug dosage and avoiding serious side effects.

Mycophenolate mofetil in patients with hepatitis C virus infection

Diagnosis and treatment of hepatitis C virus (HCV) -related autoimmune features has become a clinical challenge in HCV-infected patients, in whom chronic liver disease associated with severe autoimmune features may contribute to a very poor prognosis. Both antiviral and immunosuppressive therapies, either alone or in combination, seem likely to have a key role. Based on the experience of mycophenolate mofetil (MMF) use in HCV patients receiving organ transplantation, this new immunosuppressive agent might represent a safe and effective therapeutic option to treat HCV-related extrahepatic features. Recent data are available for the use of MMF in HCV patients with autoimmune manifestations, mainly for autoimmune cytopenias and vasculitic features. MMF may be used as monotherapy or in association with other drugs for cases of HCV-related autoimmune diseases refractory or intolerant to common immunosuppressive treatments, allowing the reduction of the drug dosage and avoiding serious side effects.

Overview of Infections in the Immunocompromised Host

Understanding the components of the immune system that contribute to host defense against infection is key to recognizing infections that are more likely to occur in an immunocompromised patient. In this review, we discuss the integrated system of physical barriers and of innate and adaptive immunity that contributes to host defense. Specific defects in the components of this system that predispose to particular infections are presented. This is followed by a review of primary immunodeficiency diseases and secondary immunodeficiencies, the latter of which develop because of a specific illness or condition or are treatment-related. The effects of treatment for neoplasia, autoimmune diseases, solid organ and stem cell transplants on host defenses are reviewed and associated with susceptibility to particular infections. In conclusion, an approach to laboratory screening for a suspected immunodeficiency is presented. Knowledge of which host defects predispose to specific infections allows clinicians to prevent, diagnose, and manage infections in their immunocompromised patients most effectively.

Trends in the use of maintenance immunosuppressive drugs among liver transplant recipients in Taiwan: a nationwide population-based study

PURPOSE

During the past two decades, many novel immunosuppressive drugs have been approved for transplant recipients. Trends in the use of maintenance immunosuppressants after liver transplantation in Asia are unclear. Thus, we aimed to analyze the prescription trends in maintenance immunosuppressive drugs among liver transplant recipients in Taiwan and compare the results with the trends reported from western countries.

METHODS

We conducted a retrospective nationwide population-based study utilizing the National Health Insurance Research Database (NHIRD) to analyze the prescribing patterns of immunosuppressants used in Taiwanese liver transplant recipients from 2000 to 2009.

RESULTS

A total of 1686 liver transplant patients and their prescriptions of immunosuppressants were analyzed. The 5-year survival rate of liver transplant recipients was 79.6%. In 2009, the major immunosuppressive therapy among liver transplant recipients was a dual-drug regimen with tacrolimus and mycophenolic acid (57.3%). Among the calcineurin inhibitors (CNI), the use of cyclosporine decreased from 58.9% to 12.5%, while the use of tacrolimus notably increased from 23.3% to 77.5%. The use of azathioprine decreased from 21.3% to 0.4%, while the use of mycophenolic acid increased from 56.1% to 76.5%. Among the mammalian target of rapamycin (mTOR) inhibitors, sirolimus was approved in 2002, and its use increased to 8.7% in 2009. In the first 3 months after liver transplantation, a total of 17 different regimens were used in 2009, compared with seven regimens in 2000.

CONCLUSIONS

Although the CNI-based combination obviously remains the major regimen, our results reveal a trend toward individualized immunosuppressive regimens among Taiwanese liver transplant recipients. Copyright © 2016 John Wiley & Sons, Ltd.

Coeliac-like duodenal pathology in orthotopic liver transplant patients on mycophenolic acid therapy

AIMS

Diarrhoea following orthotopic liver transplantation (OLT) is a significant clinical problem associated with mycophenolic acid (MPA). The histological injury pattern associated with MPA in the large bowel is well documented in the literature; however, that in the duodenum is less extensively documented. The aim of this study was to investigate the histological spectrum of duodenal injury specifically in symptomatic OLT patients on MPA, and to compare this with the spectrum in patients with coeliac disease and in normal controls.

METHODS AND RESULTS

We reviewed our pathology database for all duodenal biopsies from patients on the OLT list over a period of 19 years. Medical records, anti-tissue transglutaminase IgA serology and histology were reviewed. Of the 667 patients who underwent endoscopy, 127 had duodenal biopsies (152 biopsies). Of these, 87.5% were normal. Sixteen showed abnormal histology, and seven (43.8%) of these were on MPA at the time of biopsy. Significant features included coeliac-like changes (shortened villi and increased intraepithelial lymphocyte counts), and novel findings included increased endocrine cell counts, apoptotic counts and lamina propria eosinophil counts in comparison with normal duodenal biopsies.

CONCLUSIONS

Pathologists should be aware of the features of MPA-associated duodenal injury, including coeliac-like changes and increased apoptotic counts. In those with abnormal histology, discontinuation or a reduction in the dose of MPA should be discussed.

Is there such a thing as protocol immunosuppression in liver transplantation?

Protocol immunosuppression in liver transplantation is largely an outdated concept. Immunosuppression is now personalized to the individual patient on the basis of several factors including underlying etiology of original liver disease (e.g., HCV, hepatocellular carcinoma), renal function, metabolic co-morbidities and the patient's immunological state. These include omission of corticosteroids in HCV infection and those with major metabolic risk factors, the minimization of calcineurin inhibitors in the presence of renal dysfunction and the use of mTOR inhibitors in patients with malignancy. The basis for such decision-making is discussed in this editorial.

Clinical mycophenolic acid monitoring in liver transplant recipients

In liver transplantation, the efficacy of mycophenolate mofetil (MMF) has been confirmed in clinical trials and studies. However, therapeutic drug monitoring for mycophenolic acid (MPA) has not been fully accepted in liver transplantation as no long-term prospective study of concentration controlled vs fixed-dose prescribing of MMF has been done. This review addressed MPA measurement, pharmacokinetic variability and reasons of this variation, exposure related to acute rejection and MMF-associated side effects in liver transplant recipients. Limited sampling strategies to predict MPA area under the concentration-time curve have also been described, and the value of clinical use needs to be investigated in future. The published data suggested that a fixed-dosage MMF regimen might not be suitable and monitoring of MPA exposure seems helpful in various clinical settings of liver transplantation.

Belatacept-based immunosuppression in de novo liver transplant recipients: 1-year experience from a phase II randomized study

This exploratory phase II study evaluated the safety and efficacy of belatacept in de novo adult liver transplant recipients. Patients were randomized (N = 260) to one of the following immunosuppressive regimens: (i) basiliximab + belatacept high dose [HD] + mycophenolate mofetil (MMF), (ii) belatacept HD + MMF, (iii) belatacept low dose [LD] + MMF, (iv) tacrolimus + MMF, or (v) tacrolimus alone. All received corticosteroids. Demographic characteristics were similar among groups. The proportion of patients who met the primary end point (composite of acute rejection, graft loss, death by month 6) was higher in the belatacept groups (42–48%) versus tacrolimus groups (15–38%), with the highest number of deaths and grafts losses in the belatacept LD group. By month 12, the proportion surviving with a functioning graft was higher with tacrolimus + MMF (93%) and lower with belatacept LD (67%) versus other groups (90%: basiliximab + belatacept HD; 83%: belatacept HD; 88%: tacrolimus). Mean calculated GFR was 15–34 mL/min higher in belatacept-treated patients at 1 year. Two cases of posttransplant lymphoproliferative disease and one case of progressive multifocal leukoencephalopathy occurred in belatacept-treated patients. Follow-up beyond month 12 revealed an increase in death and graft loss in another belatacept group (belatacept HD), after which the study was terminated.

Transplantation of allograft transforming growth factor-β1 transfected CD103⁺ lamina propria dendritic cells could effectively induce antigen-specific regulatory T cells in vivo

Organ transplantation is the best treatment of some end-stage diseases such as renal failure. Unfortunately, not every transplant is successful due to rejection or dysfunction of the transplanted organ. Induction of allograft tolerance is the most important goal of clinical transplantation. Regulatory T cells (Tregs) have opened up exciting opportunities for this enterprise. Because Tregs can be induced from naïve CD4 T cells (induced Tregs [iTregs]) by lamina propria dendritic cells (LpDCs) via transforming growth factor-β (TGF-β) and retinoic acid (RA) iTregs show in vitro and in vivo functions similar to those of natural Tregs (nTregs), we sought to convert naive CD4 T cells to iTregs using mTGF-β1-modified allograft LpDCs in vivo. Adoptive transfer of mTGF-β1-modified LpDCs of BALB/c mice into C57BL/6 mice induced higher levels of mTGF-β1 and mIL-10 in sera as well as a greater proportion of antigen-specific Tregs. These data support the role of mTGF-β1-modified allograft LpDCs to induce high levels of antigen-specific Tregs in vivo.

Pharmacokinetics, electrophysiological, and morphological effects of the intravitreal injection of mycophenolic acid in rabbits

PURPOSE

To determine the half-life of mycophenolic acid (MPA) in the vitreous of New Zealand albino rabbits after intravitreal injection and the retinal toxicity of different doses of MPA.

METHODS

Ten micrograms of MPA (Roche Bioscience, Palo Alto, CA) was injected in the vitreous of 16 rabbits, animals were sacrificed at different time-points, and vitreous samples underwent high-performance liquid chromatography. For functional and morphological studies, 5 doses of MPA (0.05, 0.5, 2, 10, and 100 μg) were injected in the vitreous of 20 rabbits. As control, contralateral eyes were injected with aqueous vehicle. Electroretinograms (ERGs) were recorded before injection and at days 7, 15, and 30. Animals were sacrificed on day 30 and retinas were analyzed under light microscopy.

RESULTS

MPA half-life in the vitreous was 5.0±0.3 days. ERG revealed photoreceptor functional impairment in eyes injected with 0.5 μg and higher on day 30, while eyes injected with 100 μg presented the same changes already from day 15. No morphological change was found.

CONCLUSIONS

MPA vitreous half-life is 5.0 days. Intravitreal injection of 0.5 μg MPA and higher causes dose- and time-related photoreceptor sensitivity decrease in rabbits. The MPA dose of 0.05 μg may be safe for intravitreal use in rabbits.