Safety and effectiveness of mycophenolate mofetil associated with tacrolimus for liver transplantation immunosuppression: a systematic review and meta-analysis of randomized controlled trials

Safety and Efficacy of Mycophenolate Mofetil Associated With Tacrolimus for Kidney-pancreas and Kidney Transplantation: A Systematic Review and Meta-Analysis of Randomized Studies

INTRODUCTION

This study evaluated the efficacy and safety of mycophenolate mofetil (MMF) associated with tacrolimus (TAC) in patients undergoing kidney-pancreas and kidney transplants, in comparison with cyclosporine (CyA), azathioprine (AZA), everolimus (EVL), sirolimus (SRL), manitimus (MAN), mizoribine (MZR), and enteric-coated mycophenolate sodium (ECMPS) in combination or monotherapy.

METHODS

A systematic review and meta-analysis of randomized clinical trials was performed. The outcomes comprised acute rejection, graft loss, and adverse events.

RESULTS

Thirty studies were included. The main adverse events related to the TAC+MMF scheme were infection (36%; 95%CI: 26%-46%), including cytomegalovirus (CMV) (14%; 95%CI: 8%-20%); anemia (20%; 95%CI: 2%-37%); leukopenia (18%; 95%CI: 3%-33%); nausea (20%; 95%CI: 1%-39%); and diarrhea (26%; 95%CI:13%-40%). TAC+MMF was compared to the schemes AZA+TAC, CyA+AZA, CyA+MMF, CyA+SRL, ECMPS, EVL, MAN+TAC, MMF+SRL, MZR, TAC+AZA, TAC+EVR, TAC+MZR, TAC +SRL and TAC. TAC+MMF was associated with a lower risk of rejection than MMF monotherapy (RD: -0.24; 95%CI -0.46; -0.02). Comparing TAC+MMF with the other regimens, no significant difference was found for graft loss. TAC+MMF was associated with a higher risk of infections than MZR (RD: 0.174; 95%CI: 0.25; 0.323) and TAC monotherapy (RD: 0.07; 95%CI 0.003; 0.138).

CONCLUSION

Gastrointestinal and hematological adverse events and infections are the most common with TAC+MMF for kidney-pancreas and kidney. TAC+MMF effectively prevents acute cellular rejection, and alternatives with AZA, CyA, SRL, ECMPS, EVL, MAN, and MSR have similar efficacy and safety profiles. TAC monotherapy and MZR may be associated with a lower risk of infections.

Development of a novel UPLC-MS/MS method for the simultaneous quantification of mycophenolic mofetil, mycophenolic acid, and its major metabolites: Application to pharmacokinetic and tissue distribution study in rats

Mycophenolate mofetil (MMF) is a prodrug of mycophenolic acid (MPA) used to prevent rejection in organ transplant patients. The purpose of this study is to develop a sensitive LC-MS/MS method to simultaneously quantify MMF, MPA, and two major metabolites, mycophenolic acid-glucuronide (MPAG) and Acyl-mycophenolic acid-glucuronide (AcMPAG) and applied this method in a pharmacokinetic (PK) and tissue distribution study. A Shimadzu UHPLC system coupled to an AB Sciex QTrap 4000 mass spectrometer was used for the analysis. Protein precipitation with a mixture of methanol: acetonitrile (2:1, v:v) was used to process the plasma samples and tissue samples. Separation was achieved using an Ultra Biphenyl 5 µm column (100 × 2.1 mm) with 0.1% formic acid in water (A) and acetonitrile (B) as the mobile phases. Quantification analysis was performed under positive ionization mode using the multiple reaction monitoring (MRM) approach. The method was linear in the range of 1.22 - 1250.00 nM for all four analytes with correlation coefficient values > 0.99. The method was reproducible, with intra- and inter-day accuracy ranging from 85.0 ± 11.2-108.3 ± 6.50 for all analytes in both plasma, liver and intestine homogenates. The extraction recovery and matrix effect of plasma sample using a mixture methanol/acetonitrile (2:1, V:V) can achieve an acceptable range (<20%), but extraction recovery and matrix effect of AcMPAG decreased to 64.10 ± 15.42 in the liver and intestine homogenates. The analytes in plasma were found to be stable under bench-top, freeze-thaw, and storage conditions. The validated method was successfully applied to quantify MMF, MPA, MPAG, and AcMPAG in a rat PK study. The PK results showed MPA was the major form exposed in the plasma in rats after oral administration of MMF, but the major metabolites in the rat's tissue disposition were MPAG.

Paradox inflammatory reaction such as appendicitis epiploica and diverticulitis of the sigmoid colon under ongoing immunosuppression after previous liver transplantation (LTx)

Objective

Inflammatory reactions caused by immunosuppression appear a particular interesting disease due to its very specific and partly unclear etiopathogenesis.Based on clinical case-specific management experiences and selective references from the literature, the rare case of an acute intraabdominal inflammation as unusual complication or side effect (at the gastrointestinal [GI] tract) of the ongoing immunosuppressive medication using Mycophenolate mofetil and Tacrolimus after previous liver transplantation is to be illustrated.

Case presentation

Medical history (hx): 1) Current: A 68-years old male patient underwent abdominal CT scan because of pain in the left lower abdomen with the suspicious diagnosis of diverticulitis leading to initiation of antibiotic therapy 24 h prior to the transferral to the own hospital for adequate liver transplantation (LTx) follow-up investigation. 2) Medication contained Sitagliptin 1 × 100 mg, Omeprazol 1 × 40 mg, Mesalazin 500 mg 3 × 2, Movicol 1 (on demand), Mycophenolate mofetil 2 × 500 mg, Tacrolimus 2 × 1 mg and Hydrochlorothiazid 1 × 2.5 mg. 3) Additional diagnoses included arterial hypertension, diabetes mellitus and urinary bladder diverticle. 4) Previous surgical intervention profile comprises resection of liver segments IV/V due to HCC (2011), orthotopic liver transplantation because of HCC caused by alcohol-induced liver cirrhosis (2013) and an intervertebral disc operation (2018). Physical examination of the abdomen revealed marked tenderness in the lower left quadrant. The abdominal wall was soft and there were no defensive tension and no peritonism. The patient was in good general condition and nutritional status. He was cardiopulmonarily stable and oriented to all qualities. Diagnostic measures showed a CRP of 38.0 (normal range, < 5) mg/L and a white blood cell count within normal range. Leading diagnoses were found using abdominal CT scan, which demonstrated an extended diverticulosis and an appendicitis epiploica within the immediate subperitoneal region of the left lower abdomen with an oval fat isodense structure in the region of the sigmoid colon with surrounding inflammatory imbibition and pronounced intestinal wall. Suspicious diagnosis was the 1st episode of an uncomplicated diverticulitis of the sigmoid colon associated with an appendicitis epiploica. Therapeutic approach was given by conservative therapy with infusion therapy, analgesia as well as inital "n. p. o." and following initiation of oral nutrition. In addition, calculated antibiotic therapy with Cefuroxime and Clont was initiated. Clinical course was uneventful, with discharge on the eighth day of hospital stay with no pathological findings and substantial improvement in clinical and laboratory findings. Further advice consisted of clinical and laboratory follow-up control investigations by the family practitioner and nutritional counselling. In addition, a colonoscopy should be performed within four months.

Conclusions

The described case i) is either one of the many side effects of the immunosuppressive medication Mycophenolate mofetil and Tacrolimus listed as "colonic inflammation" and "gastrointestinal inflammation", respectively, or ii) can be considered an inflammatory response of a susceptible (gastro-)intestinal mucosa or the whole intestinal wall to microbes or microbial particles or agents caused by transplantation-associated immunosuppressive medication.

Multiple Shades of Gray-Macrophages in Acute Allograft Rejection

Long-term results following solid organ transplantation do not mirror the excellent short-term results achieved in recent decades. It is therefore clear that current immunosuppressive maintenance protocols primarily addressing the adaptive immune system no longer meet the required clinical need. Identification of novel targets addressing this shortcoming is urgently needed. There is a growing interest in better understanding the role of the innate immune system in this context. In this review, we focus on macrophages, which are known to prominently infiltrate allografts and, during allograft rejection, to be involved in the surge of the adaptive immune response by expression of pro-inflammatory cytokines and direct cytotoxicity. However, this active participation is janus-faced and unspecific targeting of macrophages may not consider the different subtypes involved. Under this premise, we give an overview on macrophages, including their origins, plasticity, and important markers. We then briefly describe their role in acute allograft rejection, which ranges from sustaining injury to promoting tolerance, as well as the impact of maintenance immunosuppressants on macrophages. Finally, we discuss the observed immunosuppressive role of the vitamin-like compound tetrahydrobiopterin and the recent findings that suggest the innate immune system, particularly macrophages, as its target.

Impact of COVID-19 Infection on Liver Transplant Recipients: Does It Make Any Difference?

The first case of coronavirus disease 2019 (COVID-19) was diagnosed in December 2019 in Wuhan, China. Since then, this novel infectious disease, caused by the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2), has grown into a pandemic with over 330 million infected individuals worldwide, many of them with innate or acquired immunosuppression.

Liver transplantation (LT) is offered as a curative therapy for end-stage liver disease as well as for acute liver failure cases. Advances in immunosuppressive therapy decreased the rates of acute and chronic graft rejection, significantly improving the quality of life.

Liver transplant recipients are considered at particularly high risk for developing critical COVID-19 infection because of their chronic immunosuppressed state. Available data are heterogeneous, and the mortality rate is variably reported in the literature. There is controversy regarding whether their immunosuppressive status is a risk or a protective factor for developing severe respiratory disease. Moreover, the mechanism of action is still unclear.

We report the clinical outcome of three liver transplant recipients who had COVID-19 pneumonia at different moments following liver transplantation. All patients received a standard immunosuppression regimen and specific antiviral therapy, requiring no invasive mechanical ventilation. They were discharged from the hospital with no long-term COVID-19 complications.