Efficacy and safety of monotherapy with mycophenolate mofetil in liver transplantation

Intraoperative Optic Nerve Sheath Diameter as a Predictor of Early Tacrolimus Neurotoxicity after Living Donor Liver Transplantation

BACKGROUND

During liver transplantation, graft reperfusion triggers cerebral hyperemia, increases intracranial pressure, and disrupts the blood-brain barrier, thereby increasing the risk for immunosuppression neurotoxicity. Therefore, we tested the intraoperative optic nerve sheath diameter (ONSD) for predicting tacrolimus neurotoxicity after liver transplantation.

BASIC PROCEDURES

We prospectively included 100 adult patients who underwent living donor liver transplantation. The ultrasonographic ONSD 5 min after reperfusion was used as the index test, whereas the occurrence of early tacrolimus neurotoxicity was used as the reference. The area under the receiver operating characteristic curve (AUROC) was used to estimate the ONSD prediction accuracy. We reported the specificity and sensitivity of ONSD 5 and 30 min after reperfusion. Cutoffs were derived from the ROC curves. In addition, we used regression to control for confounders while testing the association between the ONSD and tacrolimus neurotoxicity.

MAIN FINDINGS

The AUROC at T3 was 0.74 (95% confidence interval (CI), 0.63-0.85, P < 0.001). An ONSD of ≥6.4 mm at T3 had an 86% sensitivity (95% CI, 68%-96%) and 53% specificity (95% CI, 41%-65%). An ONSD of ≥6.4 mm at T3 had an adjusted odds ratio for tacrolimus neurotoxicity of 6.3 (95% CI, 1.9-21, P = 0.003).

CONCLUSIONS

This data indicates that intraoperative ultrasonic ONSD after reperfusion can predict tacrolimus neurotoxicity after liver transplantation.

TRIAL REGISTRATION

NCT03799770; registered on January 1st, 2019.

Immunosuppressive agents for dermatological indications in the ongoing COVID-19 pandemic: Rationalizing use and clinical applicability

The ongoing COVID-19 epidemic has brought to the fore many concerns related to use of immunosuppressive agents (ISAs) in dermatology. While it is unclear whether the patients on ISAs for skin conditions are more prone to develop COVID-19, and what impact the ISA may have on the clinical outcome if a patient does get infected, rationalizations based on the specific immune effects of each drug, and existing literature on incidence of various infections with each, are possible. In this review, we provide the readers with practically useful insights into these aspects, related to the conventional ISAs, and briefly mention the clinical outcome data available on related scenarios from other patient groups so far. In the end, we have attempted to provide some clinically useful points regarding practical use of each dermatologically relevant conventional ISA in the current scenario.

Systematic review of the evidence on the epidemiology of herpes zoster: incidence in the general population and specific subpopulations in Spain

OBJECTIVES

Herpes zoster (HZ) is an important cause of morbidity around the world, especially among the adult population aged >50 years.

STUDY DESIGN

A systematic review of the literature (up to October 31, 2016) was performed to identify available evidence on incidence of HZ in the general population and in a specific subpopulation in Spain.

METHODS

PubMed and Embase databases were searched, combining the following search terms: 'herpes zoster', 'diabetes mellitus (DM)', 'chronic obstructive pulmonary disease (COPD)', 'chronic heart failure', 'mental disorders' and 'immunocompromised'. Supplements for local scientific congresses, non-indexed Spanish journals and official epidemiological reports, potentially HZ related, were also manually searched. The inclusion criteria were the following: English or Spanish publications reporting incidence of HZ in the Spanish general population and/or specific subpopulations. No restrictions were applied on the study design or population age.

RESULTS

Among 269 references retrieved (48 PubMed, 148 Embase and 73 manual searching), 34 were finally included. Incidence of HZ in the general population ranged from 2.1 to 5.5/1000 person-years. HZ incidence ranged from 9.4 to 15.3/1000 patients with DM and from 11.0 to 11.4/1000 population with COPD or cardiovascular disease. In asthmatic patients, 6.9 HZ cases/1000 subjects were reported. The highest HZ incidence (1.3-400.0/1000 person-years) was in immunocompromised persons (10.0/1000 patients with cancer, 12.5/1000 patients with AIDS, from 5.0 to 240.0/1000 transplanted patients and from 6.6 to 27.0/1000 population with rheumatic diseases). Three studies estimated an increased risk of HZ in comparison with general population, for patients with DM (24%), COPD (39%) and COPD receiving inhaled corticosteroids (61%).

CONCLUSIONS

The results suggest a high risk of HZ in certain age groups and specific subpopulations. This study could contribute to identify target age populations and at-risk groups if implementation of HZ vaccination programmes in Spain would be considered.

Modification of immunosuppressive therapy as risk factor for complications after liver transplantation

Management of complications post-liver transplantation (LT) includes immunosuppressive manipulations with the aim to reduce the overall burden of immunologic suppression and compensate for renal, cardiovascular, metabolic toxicities, and for the increased oncologic risk. Two approaches can be implemented to reduce immunosuppression-related adverse events: upfront schedules tailored to the pretransplant individual patient's risk profile versus downstream modifications in the event of immunosuppression-related complications. Upfront strategies are supported by evidence originating from prospective randomized trials and consist of triple/quadruple schedules whereby calcineurin inhibitors (CNI)-exposure is reduced with combination of anti-CD25 monoclonal antibodies, antimetabolites and corticosteroids. Quadruple regimens allow for staggering of CNI introduction and higher renal function in the early term, but their superiority in the long term has not yet been established. A more recent upfront schedule contemplates early (4 weeks) introduction of mammalian target of rapamycin inhibitor (mTORi) everolimus and allows for reduction of CNI up to 4 years posttransplantation. Incorporation of mTORi has the potential to prolong time to recurrence for patients with hepatocellular carcinoma. However, as suggested by the available evidence, downstream immunosuppressive manipulations are more frequently adopted in clinical practice. These encompass CNI replacement and immunosuppression withdrawal. Switching CNI to mTORi monotherapy is the option most commonly adopted to relieve renal function and compensate for posttransplant malignancies. Its impact is dependent on interval from transplantation and underlying severity of renal impairment. Introduction of mTORi is associated with longer overall survival for patients with extrahepatic posttransplant malignancies, but results are awaited for recurrences of hepatocellular carcinoma. Immunosuppression withdrawal seems feasible (70%) in very long term survivors (>10 years), but is not associated with reversal of immunosuppression-related complications. Awaiting novel immunosuppressive drug categories, integration of upfront strategies with the aim to reduce CNI-exposure and a low threshold for adjustment in the posttransplant course are both advisable to improve long-term outcomes of LT.

Everolimus plus mycophenolate mofetil as initial immunosuppression in liver transplantation

BACKGROUND

The purpose of this study was to assess the efficacy and safety of a de novo immunosuppressive regimen with everolimus (EVL) plus mycophenolate mofetil (MMF) without calcineurin inhibitors (CNI) for liver transplantation. The secondary purpose was to compare the renal function with a control group of patients treated with tacrolimus plus MMF.

METHODS

Sixteen male and 4 female liver transplant patients received immunosuppression with EVL plus MMF without CNI, with induction with steroids and 16 with basiliximab also. In 10 cases it was indicated as induction immunosuppression without CNI as prevention against nephrotoxicity and neurotoxicity or recurrence of hepatocarcinoma in predisposed patients and in another 10 after withdrawing CNI during the immediate post-transplant period, before hospital discharge, as the result of toxicity, mainly nephrotoxicity and neurotoxicity or the presence of hepatocarcinoma with a high risk of recurrence. A control group comprising 31 patients taking tacrolimus plus MMF was included to compare the renal function.

RESULTS

The mean follow-up time was 24 months. One patient had a recurrence of hepatocarcinoma at 8 months after transplant. The cases of nephrotoxicity and neurotoxicity resolved favorably. There were 7 rejections (35%); 2 evolved to chronic rejection with both needing retransplantation, 2 resolved with dose adjustment, and 3 required conversion to CNI. The side effects were hyperlipidemia (25%), wound dehiscence (10%), lymphedema (10%), cytomegalovirus infection (25%), myelotoxicity (25%) and proteinuria >1 g in 1 case (5%). No differences were found in renal function between the two groups.

CONCLUSIONS

This regimen was proven to be efficient to prevent and treat nephrotoxicity and neurotoxicity with an acceptable tolerability profile. However, the high associated rejection rate indicates that great caution is required in its use during the immediate post-transplant period. It is advisable to associate the regimen with low doses of CNI and to have agile methods available to monitor EVL to enable rapid dose adjustment.

Effect of Immunosuppressive Agents on Hepatocyte Apoptosis Post-Liver Transplantation

INTRODUCTION

Immunosuppressants are used ubiquitously post-liver transplantation to prevent allograft rejection. However their effects on hepatocytes are unknown. Experimental data from non-liver cells indicate that immunosuppressants may promote cell death thereby driving an inflammatory response that promotes fibrosis and raises concerns that a similar effect may occur within the liver. We evaluated apoptosis within the liver tissue of post-liver transplant patients and correlated these findings with in vitro experiments investigating the effects of immunosuppressants on apoptosis in primary hepatocytes.

METHODS

Hepatocyte apoptosis was assessed using immunohistochemistry for M30 CytoDEATH and cleaved PARP in human liver tissue. Primary mouse hepatocytes were treated with various combinations of cyclosporine, tacrolimus, sirolimus, or MMF. Cell viability and apoptosis were evaluated using crystal violet assays and Western immunoblots probed for cleaved PARP and cleaved caspase 3.

RESULTS

Post-liver transplant patients had a 4.9-fold and 1.7-fold increase in M30 CytoDEATH and cleaved PARP compared to normal subjects. Cyclosporine and tacrolimus at therapeutic concentrations did not affect hepatocyte apoptosis, however when they were combined with MMF, cell death was significantly enhanced. Cell viability was reduced by 46% and 41%, cleaved PARP was increased 2.6-fold and 2.2-fold, and cleaved caspase 3 increased 2.2-fold and 1.8-fold following treatment with Cyclosporine/MMF and Tacrolimus/MMF respectively. By contrast, the sirolimus/MMF combination did not significantly reduce hepatocyte viability or promote apoptosis.

CONCLUSION

Commonly used immunosuppressive drug regimens employed after liver transplantation enhance hepatocyte cell death and may thus contribute to the increased liver fibrosis that occurs in a proportion of liver transplant recipients.

Immunosuppressant-associated neurotoxicity responding to olanzapine

Immunosuppressants, particularly tacrolimus, can induce neurotoxicity in solid organ transplantation cases. A lower clinical threshold to switch from tacrolimus to another immunosuppressant agent has been a common approach to reverse this neurotoxicity. However, immunosuppressant switch may place the graft at risk, and, in some cases, continuation of the same treatment protocol may be necessary. We report a case of immunosuppressant-associated neurotoxicity with prominent neuropsychiatric manifestation and describe psychiatric intervention with olanzapine that led to clinical improvement while continuing tacrolimus maintenance.

Effect of mycophenolate mofetil on hematological side effects incidence in renal transplant recipients

Mycophenolate mofetil (MMF), an immunosuppressant administered after solid organ transplantation, is generally well tolerated; however, it frequently causes hematological toxicity. In this study, we aimed to assess the relation between the pharmacokinetic parameters of MMF metabolites (mycophenolic acid [MPA] and 7-O-MPA glucuronide [MPAG]) and the adverse effects on the hematopoietic system in renal transplant recipients. The four-h pharmacokinetic profiles of MPA and MPAG were determined using the HPLC method for MMF-treated patients (n = 61) among 106 renal transplant recipients (during the late post-transplant period) participating in the study. Anemia was more frequently observed in the study group compared with the control group (30.7% vs. 20.0%) and although the difference was insignificant, plasma iron concentrations were significantly higher in patients treated with MMF (32.9 ± 9.4 μmol/L vs. 28.7 ± 9.4 μmol/L; p = 0.032). Iron supplementation was more frequently applied to patients with anemia (48.2%) compared with patients with hemoglobin within the norm (20.3%; p = 0.005). As all MPAG pharmacokinetic parameters correlated negatively with hemoglobin and hematocrit, and MPAG pharmacokinetic parameters were higher in patients with anemia, MPAG may be the predicting factor of MMF side effects. In renal transplant recipients, especially with deteriorated renal function, extensive iron supplementation may be ineffective as anemia was associated with declined renal function and was not caused by low iron concentration.

Immunomodulating options for liver transplant patients

Much has changed since the early years of liver transplantation. Improvements in post-transplant survival are largely due to more selective and less toxic immunosuppression regimens and advances in operative and perioperative care. This has allowed liver transplantation to become an extremely successful treatment option for patients with endstage liver disease. Beginning with cyclosporine, a cyclic endecapeptide of fungal origin and the first of the calcineurin inhibitors to find widespread use, immunosuppressive regimens have evolved to include additional calcineurin inhibitors, steroids, mTOR inhibitors, antimetabolites and antibodies, mostly targeting T-cell activation. This review will present currently available immunosuppressive agents used in the perioperative period of liver transplantation, as well as maintenance treatments, tailoring therapeutic strategies for specific populations, and advances in immune monitoring and tolerance.

Pharmacokinetics of free mycophenolic acid and limited sampling strategy for the estimation of area under the curve in liver transplant patients

Mycophenolate Mofetil (MMF) is widely used in preventing acute rejection in liver transplantation. Only free MPA (fMPA) can exert the pharmacological effect. In this study, we aimed to develop the new model which could be best fit to predict the fMPA area under the plasma concentration-time curve (AUC) by limited sampling strategy (LSS) in Chinese liver transplant patients. Fifty patients received MMF with the combination of tacrolimus. Free MPA concentrations were determined around day 7. Optimal subset regression analysis was used to establish the models for estimated fMPA AUC(0-12h). Three excellent better models were validated by Bootstrap analysis. Twenty-four models including four blood time point samplings were established. For the selected four models, 100% were successful and were not significantly different from the original dataset by Bootstrap analysis. The best model for prediction of fMPA AUC(0-12h) was by using C(1h), C(2h), C(4h) and C(6h). This model showed the minimal mean prediction error and the minimal mean absolute prediction error. In conclusion, the models for estimation of the fMPA AUC(0-12h) were established in liver transplant recipients and the best model for prediction of fMPA AUC was: estimated fMPA AUC=34.2+1.12C(1h)+1.29C(2h)+2.28C(4h)+3.95C(6h).

Mycophenolate mofetil monotherapy in liver transplant recipients

INTRODUCTION

Complete conversion of calcineurin inhibitor (CNI) immunosuppressant therapy to non-nephrotoxic agents such as mycophenolate mofetil (MMF) is controversial, but may be safe in selected patients, although appropriate protocols and long-term benefits of conversion are not well reported.

METHODS

We analyzed all liver transplant (LT) recipients at our institution who were converted from CNI-based therapy to MMF monotherapy because of renal dysfunction (n = 23) and compared them with patients remaining on CNI-based therapy (n = 23). Renal function, rejection episodes, and markers of CNI-related comorbidities (lipid profile, blood pressure, and glycosylated hemoglobin) were noted.

RESULTS

Overall, serum creatinine (SCr) and calculated glomerular filtration rate improved on MMF monotherapy. This improvement was significant when compared with patients who remained on CNI-based therapy. Improvement was most pronounced in patients with milder renal dysfunction (SCr <2.2 mg/dL prior to conversion) (n = 14) with decrease in SCr from 1.63 ± 0.29 to 1.34 ± 0.26 mg/dL (p = 0.02) at last follow-up. Five patients on MMF monotherapy (21.7%) progressed to end-stage renal disease (ESRD), while only two (8.7%) had rejection episodes following conversion. Clinical markers of CNI-related comorbidities also improved. MMF monotherapy was well tolerated.

CONCLUSION

In summary, our data support the safety and efficacy of CNI to MMF monotherapy conversion.

Cyclosporine monotherapy in cardiac transplantation: review of the literature

The immunosuppressive therapy after organ transplantation should be tailored to balance the tolerance and the reaction of the recipient against the graft to avoid lack of immunosuppression or an excess of drugs. The drugs currently used may induce serious side effects with negative impact on recipient's survival and quality of life even if lack of immunosuppression may induce acute graft rejection and patient's death. The introduction of new drugs as mammalian target of rapamycin (mTOR) inhibitors allows tailoring of the immunosuppressive therapy on patient characteristics, by the use of drug association and the reduction of the overall dose. There are few cases where the necessity of reduction of the immunosuppressive therapy should be considered, as what happens in cases of severe systemic infections. Some anecdotal reports of the use of cyclosporine monotherapy (CM) in heart transplantation have been presented many years ago: the main limitations of these reports were the reasons of the switch to CM and the limited number of patients that did not allow clarification of the indications and the applicability of the CM. The aim of our review is to offer an up-to-date research of the use of CM after heart transplantation for physicians enrolled in the management of such complicated patients. The discussion will start from the kidney and liver transplantation and will arrive to the heart transplantation. However, we suggest a very careful selection of patients to be treated with CM because the use must be restricted to cases of severe side effects caused by multiple therapies because the multiple approaches has the main advantage of the synergistic action of the drugs. In conclusion, CM must be use for selected low-immunologic-risk patients, and it could be carefully used for stable patients over the long-term follow-up when the risk of acute rejection has nearly disappeared. Our article is of historical interest since we do not use anymore cyclosporine monotherapy.

Neurologic complications after solid organ transplantation

Neurologic complications are common after solid organ transplantation and are associated with significant morbidity. Approximately one-third of transplant recipients experiences neurologic alterations with incidence ranging from 10% to 59%. The complications can be divided into such of those common to all types of transplant and others of those specific to transplanted organ. The most common complication seen with all types of transplanted organ is neurotoxicity attributable to immunosuppressive drugs, followed by seizures, opportunistic central nervous system (CNS) infections, cardiovascular events, encephalopathy and de novo CNS neoplasms. Amongst immunosuppressants, calcineurin inhibitors are the main drugs involved in neurotoxicity, leading to complications which ranges from mild symptoms, such as tremors and paresthesia to severe symptoms, such as disabling pain syndrome and leukoencephalopathy. Neurologic complications of liver transplantation are more common than that of other solid organ transplants (13-47%); encephalopathy is the most common CNS complication, followed by seizures; however, central pontine myelinolysis can appear in 1-8% of the patients leading to permanent disabilities or death. In kidney transplanted patients, stroke is the most common neurologic complication, whereas cerebral infarction and bleeding are more typical after heart transplantation. Metabolic, electrolyte and infectious anomalies represent common risk factors; however, identification of specific causes and early diagnosis are still difficult, because of patient's poor clinical status and concomitant systemic and metabolic disorders, which may obscure symptoms.