A prospective analysis of the effects of enteric-coated mycophenolate sodium and mycophenolate mofetil co-medicated with a proton pump inhibitor in kidney transplant recipients at a single institute in China

The impact of omeprazole on mycophenolate pharmacokinetics in kidney transplant recipients

Background

The absorption rates of mycophenolate mofetil (MMF) and enteric-coated mycophenolate sodium (EC-MPS) may be influenced by the concomitant use of omeprazole.

Methods

One hundred kidney transplant patients were recruited during their outpatient visits, including 50 on MMF and 50 on EC-MPS. At the clinic, a predose mycophenolic acid (MPA) sample (C0) was collected; subsequently, the participants received the proton-pump inhibitor omeprazole along with either MMF or EC-MPS. Two more blood samples were collected at 1.5 and 3.5 hours and used to estimate an area under the curve (AUC) from zero to 12 hours [AUC (0-12)].

Results

The mean number of months after transplant was 92 months. The median AUC (0-12) and C0 results were 62.2 mg·h/L and 2.0 mg/L for the MMF group and 71.9 mg·h/L and 1.8 mg/L for the EC-MPS group (P = 0.160 and 0.225, respectively). Interestingly, 54% of the MMF group and 62% of the EC-MPS group showed AUCs above the target values. The correlation between MPA C0 and the predicted AUC was poor in both groups.

Conclusion

Omeprazole can be safely co-administered with either MMF or EC-MPS, as it did not compromise the MPA exposure. Unexpectedly, however, a high percentage of patients presented MPA AUCs exceeding the target value, highlighting the importance of periodically assessing MPA level.

The Effect of Proton Pump Inhibitor Use on Renal Function in Kidney Transplanted Patients

Recently, proton pump inhibitor (PPI) intake has been linked to acute kidney injury and chronic kidney disease. The objective of this study was to assess the effect of PPIs on renal function and rejection rate in kidney transplant patients. We performed a single center, retrospective analysis of 455 patients who received a kidney transplant between May 2010 and July 2015. Median follow-up time was 3.3 years. PPI prescription was assessed in half-year intervals. Primary outcome parameters were the estimated glomerular filtration rate (eGFR), change in the eGFR, and >30% and >50% eGFR decline for different time periods (up to four years post-transplantation). Our secondary outcome parameter was occurrence of biopsy proven acute rejection (BPAR) in the first two years after transplantation. Except for >30% eGFR decline from half a year to two years post-transplantation (p = 0.044) and change in the eGFR, >30% and >50% eGFR decline showed no association with PPI intake in our patient cohort (p > 0.05). Similarly, by analyzing 158 rejection episodes, BPAR showed no correspondence with mean daily PPI intake. We conclude that prolonged PPI intake has no relevant adverse effect on kidney transplant function or rejection rates. Polypharmacy, however, remains a problem in renal transplant recipients and it is thus advisable to question the necessity of PPI prescriptions when clear indications are missing.

Proton pump inhibitors and adverse effects in kidney transplant recipients: A meta-analysis

BACKGROUND

The adverse renal effects of proton pump inhibitors (PPIs) are increasingly recognized in both the general population and patients with chronic kidney disease. Several pharmacokinetic studies have also raised concerns regarding the interaction between PPIs and immunosuppressive drugs in transplant patients. Whether the adverse effects of PPIs have a clinical significance in kidney transplant recipients remains unclear. We performed this meta-analysis to assess the risk of adverse effects in kidney transplant recipients on PPI compared with those without PPI exposure.

AIM

To investigate the risk of acute rejection, graft loss, hypomagnesemia, renal dysfunction, and overall mortality in kidney transplant recipients on PPI compared with those without PPI exposure.

METHODS

A systematic review was conducted in MEDLINE, EMBASE, and Cochrane databases from inception through October 2018 to identify studies that evaluated the adverse effects of PPIs in kidney transplant recipients, including biopsy-proven acute rejection, graft loss, hypomagnesemia, renal function, and overall mortality. Effect estimates from the individual studies were extracted and combined using random-effect, generic inverse variance method of DerSimonian and Laird. The protocol for this meta-analysis is registered with PROSPERO, No. CRD42018115676.

RESULTS

Fourteen observational studies with 6786 kidney transplant recipients were enrolled. No significant association was found between PPI exposure and the risk of biopsy-proven acute rejection at ≥ 1 year [pooled odds ratio (OR), 1.25; 95% confidence interval (CI), 0.82-1.91, I² = 55%], graft loss at 1 year (pooled OR = 1.30, 95%CI: 0.75-2.24, I² = 0%) or 1-year mortality (pooled OR = 1.53, 95%CI: 0.90-2.58, I² = 34%). However, PPI exposure was significantly associated with hypomagnesemia (pooled OR = 1.56, 95%CI: 1.19-2.05, I² = 27%). Funnel plots and Egger regression asymmetry test were performed and showed no publication bias.

CONCLUSION

PPI use was not associated with significant risks of higher acute rejection, graft loss, or 1-year mortality. However, the risk of hypomagnesemia was significantly increased with PPI use. Thus, future studies are needed to assess the impact of PPIs on long-term outcomes.

Adverse effects of mycophenolic acid in renal transplant recipients: gender differences

Background Mycophenolic acid is widely used immunosuppressive drug, associated with adverse effects which increase patient morbidity and decrease medication adherence. Objective To evaluate the adverse effects in renal transplant recipients under mycophenolate treatment with respect to gender. Setting University Clinical Centre of Nis, Clinic of Nephrology, Serbia. Method This research included 96 renal transplant recipients, who received immunosuppressive regimen, based on tacrolimus or cyclosporin A, prednisone and mycophenolic acid. The high-performance liquid chromatography method combined with protein precipitation was used for the analysis of mycophelate concentration in human plasma. Drug concentration and dose-adjusted concentration were determined with respect to the patients' gender. An adverse effect scoring system developed by nephrologists within the University of Buffalo Nephrology/Transplant Program was used to monitor adverse effects of therapy. Main outcome measure Individual and scores of adverse effects in relation to the dosing regimen and gender. Results Results showed statistically lower dose and concentrations in men compared to the women in our investigation group. Also, female patients demonstrated higher mean scores (cumulative and subscores) within the same dosing regimens of mycophenolic acid. The gastrointestinal score was significantly higher in women who received a dose greater than 720 mg compared to men (0.20 ± 0.12 vs 0.12 ± 0.12). Women demonstrated higher individual adverse effects such as diarrhea and skin changes (41.7 vs 17.0; p = 0.038 and 62.5 vs 30.2; p = 0.037, respectively). Conclusions The results of our research showed that recipients' gender may play an important role in pharmacokinetic profile of mycophenolic acid, suggesting that women had higher concentration of mycophenolic acid and more serious side effects.

Influence of uridine diphosphate-glucuronosyltransferases (1A9) polymorphisms on mycophenolic acid pharmacokinetics in patients with renal transplant

Background: There are differences in pharmacokinetic of mycophenolic acid among individuals. The UGT1A9 enzyme is of special interest since it is the main enzyme involved in the glucuronidation of MPA. Single nucleotide polymorphisms in the UGT1A9 gene may be responsible for individual differences in the pharmacokinetics of MPA. The aim of this study was to explain MPA pharmacokinetics in UGT1A9 1399 C > T polymorphisms in Turkish renal transplant patients.

Patients and methods: One hundred and twenty-five living-donor transplant recipients and 100 healthy control subjects underwent UGT1A9 1399 C > T genotyping using polymerase chain reaction–restriction fragment length polymorphism. Concentrations of MPA were determined with Cloned Enzyme Donor Immunoassay (CEDIA). Besides that, all the patients were monitored for acute rejection and graft function during the study period.

Results: The UGT1A9 1399 C > T CC, CT, and TT genotype frequencies among patients were, respectively, 68.0%, 23.2%, and 8.8%. The CC, CT, and TT genotype frequencies among controls were, respectively, 63.0%, 23.0%, and 14.0%. There was no significant difference between patients and controls (p = .480, p = .999, p = .286, respectively). At first month, respectively, through blood concentrations of MPA were significantly higher in UGT1A9 1399 C > T TT carriers than in CT and CC carriers (p = .046). The doses for these patients were lower at first month (p = .021). Acute rejection episodes were not associated with the CC vs CT or TT genotypes (p = .064).

Conclusions: Our results demonstrated a correlation between the UGT1A9 1399 C > T polymorphism and MPA pharmacokinetics among renal transplant patients. Determination of UGT1A9 polymorphism may help to achieve target of MPA blood concentrations.

Influence of Proton Pump Inhibitors on Mycophenolic Acid Pharmacokinetics in Patients With Renal Transplantation and the Relationship With Cytochrome 2C19 Gene Polymorphism

BACKGROUND

Most patients have serious digestive complications after renal transplantation. Therefore, it is important to protect gastrointestinal function to improve the survival rate of transplant patients. Proton pump inhibitors (PPIs) such as lansoprazole and rabeprazole are widely administered to renal transplant patients with mycophenolic acid (MPA) in the perioperative period. PPIs are metabolized by cytochrome (CYP) 2C19 enzymes. Mycophenolate sodium (MYF) and mycophenolate mofetil (MMF) have been used in immunosuppression. Clinically relevant drug-drug interactions have been described between immunosuppressive drugs. In the present study, we investigated the drug interaction between MPA and lansoparazole or rabeprazole and the impact of CYP2C19 polymorphisms on these drug interactions after renal transplantation.

MATERIALS AND METHODS

A total of 125 renal transplant patients taking MPA derivatives between 2012 and 2016 were included in this study. The 125 patients were divided into 6 groups: MMF/tacrolimus/steroid together with lansoprazole or rabeprazole; MYF/tacrolimus/steroid together with lansoprazole or rabeprazole and without PPI. The single nucleotide polymorphisms of CYP2C19 were determined by the polymerase chain reaction-restriction fragment length polymorphism. Plasma concentrations of MPA were measured by cloned enzyme donor immunoassay. Clinical parameters such as incidence of delayed graft function and acute rejection, the rate of change of serum creatinine, toxicity, and gastrointestinal adverse effects were analyzed retrospectively.

RESULTS

The mean concentrations of MPA in the MYF group were higher than those in the MMF group. The mean dose-adjusted blood concentration of MPA coadministered with lansoprazole was lower than that of MPA with rabeprazole or without PPI in MMF and MYF groups (P < .05). In patients with the CYP2C19*2/*2 genotype, the mean concentrations of MMF with lansoprazole were significantly lower than those with rabeprazole with MMF or without PPI (P < .05). Gastrointestinal side effects were significantly higher in MMF with lansoprazole group than in MYF with lansoprazole group (P < .05). However, no differences were found according to genotype distribution in all groups (P > .05).

CONCLUSION

Polymorphisms in CYP2C19 are related to the metabolic oxidation of drugs to varying degrees. Both genetic and clinical factors in pharmacokinetics may help to make further progress toward individualized therapy to yield maximum efficacy with minimal side effects.

The Diagnosis and Treatment of Systemic Lupus Erythematosus

BACKGROUND

Systemic lupus erythematosus (SLE) is an autoimmune disease with a prevalence of 36.7/100 000 in Germany and a female/male ratio of 4:1. The clinical course is variable, with a broad spectrum of organ manifestations; lupus nephritis develops in about half of all patients.

METHODS

This review is based on a selective search of PubMed and the Cochrane Library, including current guidelines and expert recommendations.

RESULTS

Assessment of clinical symptoms, laboratory findings, and optional biopsy results are the basis for early diagnosis of SLE. All patients should be treated with antimalarials as soon as the diagnosis is confirmed. In particular, hydroxychloroquine is associated with a higher rate of remission, fewer relapses, and reduced damage in the course of the disease, even in lupus nephritis. High-dose glucocorticoids should be given only when acutely indicated; immunosuppressives such as azathioprine, methotrexate, or mycophenolate mofetil may be administered to reduce glucocorticoids, according to the EULAR recommendations. Belimumab was recently approved as add-on therapy in autoantibody-positive SLE patients with high disease activity unresponsive to standard treatment. Short-term induction pulse therapy with low-dose intravenous cyclophosphamide, as well as continued mycophenolate mofetil treatment are advances in lupus nephritis.

CONCLUSION

The long-term prognosis for SLE has improved markedly in recent decades because of earlier diagnosis and optimized treatment. Further research and randomized controlled trials are needed for the development of specifically targeted therapies.

Effect of the Prophylactic Use of Proton-Pump Inhibitors on the Pattern of Gastrointestinal Symptoms in Patients Late After Kidney Transplant

OBJECTIVES

Although immunosuppressive drugs have been recognized as leading causes of gastrointestinal symptoms after kidney transplant, other widely used medications such as proton-pump inhibitors recently have been implicated. Our aim was to study the effects of chronic proton-pump inhibitor therapy on gastrointestinal symptoms in clinically stable patients late after kidney transplant.

MATERIALS AND METHODS

The study comprised 100 kidney transplant recipients (66 men and 34 women, mean age of 49 ± 12 y, mean time after transplant of 56 ± 46 mo). All patients completed the Gastrointestinal Symptoms Rating Scale and the Quality of Life Questionnaire SF-8 surveys.

RESULTS

The most commonly reported symptoms included borborygmus (27%), flatulence (23%), abdominal distension (18%), urgent need of defecation (17%), and heartburn, acid reflux, and eructation (13%). Proton-pump inhibitors were chronically used by 50% of patients and sporadically by 33%. Gastrointestinal Symptoms Rating Scale scores were higher in patients who used proton-pump inhibitors (mean score of 7.8 ± 5.5 vs 4.6 ± 3.0; P = .013). Total score of items representing diarrhea in the Gastrointestinal Symptoms Rating Scale (increased passage of stools, loose stools, urgent need of defecation, incomplete evacuation) was higher in patients treated with proton-pump inhibitors than in those not treated (2.3 ± 2.2 vs 1.3 ± 1.9; P = .04).

CONCLUSIONS

Chronic use of proton-pump inhibitors may increase the prevalence of gastrointestinal symptoms, particularly diarrhea, in patients late after kidney transplant.

Enteric-coated mycophenolate sodium containing GvHD prophylaxis reduces GvHD rate after allogeneic HSCT

OBJECTIVES

The aim of this study was to evaluate whether cyclosporine A (CsA)-based Graft vs. Host Disease (GvHD) prophylaxis with enteric-coated mycophenolate sodium (EC-MPS) instead of mycophenolate mofetil (MMF) or methotrexate (MTX) reduces the GvHD incidence and lowers gastrointestinal (GI-) toxicities.

METHODS

In a retrospective analysis of 102 allogeneic hematopoietic stem cell transplant (HSCT) patients, incidences of overall and severe aGvHD (>II°), cGvHD as well as overall and severe (CTC >II°) GI-toxicities were compared between GvHD prophylaxis containing EC-MPS vs. MMF or MTX (control group).

RESULTS

The overall aGvHD rate was significantly lower in the EC-MPS group compared to the control (47% vs. 72%, P = 0.022) with lower rates of severe aGvHD (10% vs. 25%, P = 0.088) and cGvHD (20% vs. 39%, P = 0.065). Prophylaxis with EC-MPS remained significantly associated with a lower aGvHD rate in a multiple logistic regression model. GI-toxicities did not differ between both groups except for severe abdominal pain for which the incidence was increased in the EC-MPS group (17% vs. 3%, P = 0.022).

CONCLUSIONS

This data support the hypothesis that replacement of MMF or MTX by EC-MPS reduces GvHD rates after HSCT. This appears not to be due to a reduced GI-toxicity of EC-MPS.

Immunosuppressant MPA Modulates Tight Junction through Epigenetic Activation of MLCK/MLC-2 Pathway via p38MAPK

BACKGROUND

Mycophenolic acid (MPA) is an important immunosuppressive drug (ISD) prescribed to prevent graft rejection in the organ transplanted patients, however, its use is also associated with adverse side effects like sporadic gastrointestinal (GI) disturbances. Recently, we reported the MPA induced tight junctions (TJs) deregulation which involves MLCK/MLC-2 pathway. Here, we investigated the global histone acetylation as well as gene-specific chromatin signature of several genes associated with TJs regulation in Caco-2 cells after MPA treatment.

RESULTS

The epigenetic analysis shows that MPA treatment increases the global histone acetylation levels as well as the enrichment for transcriptional active histone modification mark (H3K4me3) at promoter regions of p38MAPK, ATF-2, MLCK, and MLC-2. In contrast, the promoter region of occludin was enriched for transcriptional repressive histone modification mark (H3K27me3) after MPA treatment. In line with the chromatin status, MPA treatment increased the expression of p38MAPK, ATF-2, MLCK, and MLC-2 both at transcriptional and translational level, while occludin expression was negatively influenced. Interestingly, the MPA induced gene expression changes and functional properties of Caco-2 cells could be blocked by the inhibition of p38MAPK using a chemical inhibitor (SB203580).

CONCLUSIONS

Collectively, our results highlight that MPA disrupts the structure of TJs via p38MAPK-dependent activation of MLCK/MLC-2 pathway that results in decreased integrity of Caco-2 monolayer. These results led us to suggest that p38MAPK-mediated lose integrity of epithelial monolayer could be the possible cause of GI disturbance (barrier dysfunction) in the intestine, leading to leaky style diarrhea observed in the organ-transplanted patients treated with MPA.

No relevant pharmacokinetic interaction between pantoprazole and mycophenolate in renal transplant patients: a randomized crossover study

AIMS

Mycophenolic acid (MPA) suppresses lymphocyte proliferation through inosine monophosphate dehydrogenase (IMPDH) inhibition. Two formulations have been approved: mycophenolate mofetil (MMF) and enteric-coated mycophenolate sodium (EC-MPS). Pantoprazole (PAN) inhibits gastric acid secretion, which may alter MPA exposure. Data from healthy volunteers suggest a significant drug-drug interaction (DDA) between pantoprazole and MPA. In transplant patients, a decreased MPA area under the concentration-time curve (AUC) may lead to higher IMPDH activity, which may lead to higher acute rejection risk. Therefore this DDA was evaluated in renal transplant patients under maintenance immunosuppressive therapy.

METHODS

In this single-centre, open, randomized, four-sequence, four-treatment crossover study, the influence of PAN 40 mg on MPA pharmacokinetics such as (dose-adjusted) AUC0-12 h (dAUC) was analysed in 20 renal transplant patients (>6 months post-transplantation) receiving MMF (1-2 g day(-1) ) and EC-MPS in combination with ciclosporin. The major metabolite MPA glucuronide (MPAG) and the IMPDH activity were also examined.

RESULTS

MMF + PAN intake led to a lowest mean dAUC for MPA of 41.46 ng h ml(-1) mg(-1) [95% confidence interval (CI) 32.38, 50.54], while MPA exposure was highest for EC-MPS + PAN [dAUC: 46.30 ng h ml(-1) mg(-1) (95% CI 37.11, 55.49)]. Differences in dAUC and dose-adjusted maximum concentration (dCmax) were not significant. Only for MMF [dAUC: 41.46 ng h ml(-1) mg(-1) (95% CI 32.38, 50.54)] and EC-MPS [dAUC: 43.39 ng h ml(-1) mg(-1) (95% CI 33.44, 53.34)] bioequivalence was established for dAUC [geometric mean ratio: 101.25% (90% CI 84.60, 121.17)]. Simultaneous EC-MPS + PAN intake led to an earlier time to Cmax (tmax) [median: 2.0 h (min-max: 0.5-10.0)] than EC-MPS intake alone [3 h (1.5-12.0); P = 0.037]. Tmax was not affected for MMF [1.0 h (0.5-5.0)] ± pantoprazole [1.0 h (0.5-6.0), P = 0.928). No impact on MPAG pharmacokinetics or IMPDH activity was found.

CONCLUSION

Pantoprazole influences EC-MPS and MMF pharmacokinetics but as it had no impact on MPA pharmacodynamics, the immunosuppressive effect of the drug was not impaired.