Immunosuppressive drugs and the gastrointestinal tract in renal transplant patients. Transplant Rev (Orlando). 2019;33:55-63. [PMID: 30473173 DOI: 10.1016/j.trre.2018.11.001]

The hidden pharmacokinetic challenge: diarrhea's influence on cyclosporine therapy: a case series

Background

Cyclosporine is used as an immunosuppressive drug to improve graft survival rates in the field of organ transplantation. Therapeutic drug monitoring [TDM] of cyclosporine in transplant patients is crucial for optimizing drug dosage and minimizing the risks. Diarrhea is a common gastrointestinal condition, resulting in pharmacokinetic, malabsorption, and clinical consequences for people who rely on cyclosporine medication.

Case presentations

The case series discusses three pediatric patients who underwent therapeutic drug monitoring of cyclosporine to guide their treatment. The first two cases involved post-renal transplant patients with glomerulonephritis, while the third case involved a patient with tubulointerstitial kidney disease. TDM was employed to guide dose adjustments. The first patient initially received 15 mg/kg but showed high trough concentration. The dosage was gradually reduced, while diarrhea was managed. The second and third patients exhibited a similar trend which also necessitated dose adjustments.

Clinical discussion

Diarrhea was identified as a factor impacting cyclosporine levels. This case series evaluated the impact of diarrhea on cyclosporine therapeutic levels in three pediatric renal transplant patients. TDM in cyclosporine therapy is significant due to its narrow therapeutic index and variable pharmacokinetics. Elevated trough concentrations led to a gradual dose reduction to achieve the target levels.

Conclusion

This case series highlights the importance of TDM-guided dosing of cyclosporine, particularly in patients with diarrhea, to maintain target trough concentrations.

Gastrointestinal challenges in nephropathic cystinosis: clinical perspectives

Gastrointestinal (GI) sequelae, such as vomiting, hyperacidity, dysphagia, dysmotility, and diarrhea, are nearly universal among patients with nephropathic cystinosis. These complications result from disease processes (e.g., kidney disease, cystine crystal accumulation in the GI tract) and side effects of treatments (e.g., cysteamine, immunosuppressive therapy). GI involvement can negatively impact patient well-being and jeopardize disease outcomes by compromising drug absorption and patient adherence to the strict treatment regimen required to manage cystinosis. Given improved life expectancy due to advances in kidney transplantation and the transformative impact of cystine-depleting therapy, nephrologists are increasingly focused on addressing extra-renal complications and quality of life in patients with cystinosis. However, there is a lack of clinical data and guidance to inform GI-related monitoring, interventions, and referrals by nephrologists. Various publications have examined the prevalence and pathophysiology of selected GI complications in cystinosis, but none have summarized the full picture or provided guidance based on the literature and expert experience. We aim to comprehensively review GI sequelae associated with cystinosis and its treatments and to discuss approaches for monitoring and managing these complications, including the involvement of gastroenterology and other disciplines.

Sea urchin nanostructured nickel cobaltite modified carbon cloth integrated wearable patches for the on-site detection of the immunosuppressant drug mycophenolate mofetil

Mycophenolate mofetil (MpM) is a medication used to prevent the rejection of transplanted organs, particularly in kidney, heart, and liver transplant surgeries. It is extremely important to be conscious that MpM can raise the risk of severe infections and some cancers if it exceeds the recommended dose while lower doses will result in organ rejections. So, it is essential to monitor the dosage of MpM in real time in the micromolar range. In this work, we have synthesized 3-aminopropyltriethoxysilane (APTES) functionalized nickel cobaltite (NiCo2O4) and this amino functionalization was chosen to enhance the stability and electrochemical activity of NiCo2O4. The enhanced activity of NiCo2O4 was used for developing an electrochemical sensor for the detection of MpM. APTES functionalized NiCo2O4 was coated on carbon cloth and used as the working electrode. Surface functionalization with APTES on NiCo2O4 was aimed at augmenting the adsorption/interaction of MpM due to its binding properties. The developed sensor showed a very low detection limit of 1.23 nM with linear ranges of 10-100 nM and 1-100 μM and its practical applicability was examined using artificial samples of blood serum and cerebrospinal fluid, validating its potential application in real-life scenarios.

Holistic care and symptom management for pediatric kidney transplant recipients

While many aspects of life may improve substantially for children and young people undergoing kidney transplant, there may be new challenges including symptoms that can be detrimental to health-related quality of life. Addressing symptoms requires attention to patient and family perspectives and a holistic approach grounded in symptom management. The interdisciplinary pediatric nephrology transplant team should be attuned to the prevalence of common symptoms including fatigue, anxiety, depression, post-traumatic stress, pain, and sleep disturbances, as well as poor body image and sexual health. These common symptoms require regular assessment with a focus on appropriate interventions and how care may be impacted by transplant status.

SLCO1B3 T334G polymorphisms and mycophenolate mofetil-related adverse reactions in kidney transplant recipients

Background: The correlation between SLCO1B3 T334G polymorphisms and mycophenolate mofetil (MMF) adverse reactions in kidney recipients is unknown. Methods: A single-center, retrospective study was performed in which 111 patients were divided into four groups according to the type of adverse effect experienced. The clinical data and concentrations of MMF at different months after transplantation were statistically analyzed. Results: The G allele in the gastrointestinal reaction group was significantly higher than that in the no adverse effects group (p < 0.05). Logistic regression model showed that the SLCO1B3 T334G genotype was an independent risk factor for gastrointestinal reactions caused by MMF. Conclusion: Patients with the SLCO1B3 T334G GG genotype were more likely to experience gastrointestinal reactions.

Study on alleviate effect of Wuzhi capsule (Schisandra sphenanthera Rehder & E.H. Wilson extract) against mycophenolate mofetil-induced intestinal injury

ETHNOPHARMACOLOGICAL RELEVANCE

Schisandra sphenanthera Rehder & E.H. Wilson (S. sphenanthera) is a botanical medicine included in the 2020 edition of the ChP that has a variety of medicinal activities, including hepatoprotective, anticancer, antioxidant and anti-inflammatory properties. Wuzhi capsule (WZ) is a proprietary Chinese medicine made from an ethanolic extract of S. sphenanthera that is commonly used to treat drug-induced liver injury. However, there are no research reports exploring the effects of WZ on the prevention of mycophenolate mofetil (MMF)-induced intestinal injury and its underlying mechanisms.

AIM OF THE STUDY

This experiment aimed to evaluate the ameliorative effect of WZ on MMF-induced intestinal injury in mice and its underlying mechanisms.

MATERIALS AND METHODS

A mouse model of MMF-induced intestinal injury was established and treated with WZ during the 21-day experimental period. The pathological characteristics of the mouse ileum were observed. Tight junction (TJ) protein changes were observed after immunofluorescence staining and transmission electron microscopy, and ROS levels were measured by using DHE fluorescent dye and the TUNEL assay for apoptosis. The expression of p65, p-p65, IκBα, p-IκBα, the TJ proteins occludin and ZO-1 and the apoptosis-related proteins Bax, Bcl-2, cleaved caspase-3 and caspase-3 were analysed by Western blot. Levels of DAO, ET, TNF-α, IL-1β, IL-6, IFN-γ, MDA and SOD were analysed by using kits.

RESULTS

MMF activated the NF-κB signaling pathway to cause intestinal inflammation, increased intestinal permeability, changed the expression of TJ protein in the intestinal epithelium, and increased oxidative stress and apoptosis levels. WZ significantly downregulated the expression of p-p65 and p-IκBα to relieve the inflammatory response, reduced intestinal permeability, maintained intestinal TJ protein expression, and reduced intestinal oxidative stress and apoptosis.

CONCLUSION

Our research suggested that MMF can cause intestinal injury; by contrast, WZ may exert anti-inflammatory, antioxidant and apoptosis-reducing effects to alleviate MMF-induced intestinal injury.

Comparison of Renal Responses Between Continuous Mycophenolate Mofetil and Conversion from Mycophenolate Mofetil to Enteric-Coated Mycophenolate Sodium in Lupus Nephritis

BACKGROUND

Mycophenolate mofetil (MMF) is extensively used for induction and maintenance therapy in patients with lupus nephritis (LN). Enteric-coated mycophenolate sodium (EC-MPS) was developed to reduce the adverse gastrointestinal effects of MMF. However, the therapeutic efficacy of MMF and EC-MPS in LN remains unclear. This study aimed to examine the treatment effects of EC-MPS in LN patients with prior MMF exposure.

METHODS

In this medical records review study, we included 54 LN patients, of whom 34 converted from MMF to EC-MPS at equimolar doses in 2016-2018 (nonmedical switching group) and 20 received continuous MMF treatment. Patients achieving complete remission or partial remission before the conversion were categorized as responders, whereas those who had never achieved complete remission or partial remission were categorized as nonresponders.

RESULTS

Baseline proteinuria was higher in the nonmedical switching group. Although elevation in proteinuria was observed after nonmedical switching, the serum creatinine concentration and estimated glomerular filtration rate both improved. Responders in the nonmedical switching group had lower proteinuria and higher complement 3 levels. In the subgroup analysis, albeit the modest increase in daily urine protein, anti-double-stranded DNA antibody levels, estimated glomerular filtration rate, and complements 3 and 4 seemed comparable after conversion.

CONCLUSION

Switching to EC-MPS demonstrated a similar short-term renal response to continuous MMF treatment in LN patients. Prospective randomized trials are required to verify our findings.

Current status of glucocorticoid usage in solid organ transplantation

Glucocorticoids (GCs) have been the mainstay of immunosuppressive therapy in solid organ transplantation (SOT) for decades, due to their potent effects on innate immunity and tissue protective effects. However, some SOT centers are reluctant to administer GCs long-term because of the various related side effects. This review summarizes the advantages and disadvantages of GCs in SOT. PubMed and Scopus databases were searched from 2011 to April 2021 using search syntaxes covering “transplantation” and “glucocorticoids”. GCs are used in transplant recipients, transplant donors, and organ perfusate solution to improve transplant outcomes. In SOT recipients, GCs are administered as induction and maintenance immunosuppressive therapy. GCs are also the cornerstone to treat acute antibody- and T-cell-mediated rejections. Addition of GCs to organ perfusate solution and pretreatment of transplant donors with GCs are recommended by some guidelines and protocols, to reduce ischemia-reperfusion injury peri-transplant. GCs with low bioavailability and high potency for GC receptors, such as budesonide, nanoparticle-mediated targeted delivery of GCs to specific organs, and combination use of dexamethasone with inducers of immune-regulatory cells, are new methods of GC application in SOT patients to reduce side effects or induce immune-tolerance instead of immunosuppression. Various side effects involving different non-targeted organs/tissues, such as bone, cardiovascular, neuromuscular, skin and gastrointestinal tract, have been noted for GCs. There are also potential drug-drug interactions for GCs in SOT patients.

Post-COVID-19 Sydrome and Decrease in Health-Related Quality of Life in Kidney Transplant Recipients after SARS-COV-2 Infection-A Cohort Longitudinal Study from the North of Poland

Introduction: Patients after SARS-CoV-2 infection frequently face “Post-COVID-19 Syndrome”, defined by symptoms that develop during or after COVID-19, continue for more than 12 weeks, and are not explained by an alternative diagnosis. We aimed to evaluate the presence of post-COVID-19 syndrome and its predictors in kidney transplant recipients (KTR) 6 months after the disease. Materials and Methods: A total of 67 KTR (38 m) with a mean age of 53.6 ± 14 years, 7.3 ± 6.4 years post-transplant were included in the cohort longitudinal study. Thirty-nine (58.2%) of them were hospitalized, but not one required invasive ventilation therapy. They were interviewed 6 months after being infected, with a series of standardized questionnaires: a self-reported symptoms questionnaire, the modified British Medical Research Council (mMRC) dyspnea scale, EQ-5D-5L questionnaire, and EQ-VAS scale. Results: Post-COVID-19 syndrome was diagnosed in 70.1% of KTR and 26.9% of them reported at least three persistent symptoms. The most common symptoms were fatigue (43.3%), hair loss (31.3%), memory impairment (11.9%), muscle aches, and headaches (11.9%). Dyspnea with an mMRC scale grade of at least 1 was reported by 34.3% patients vs. 14.9% before infection; 47.8% stated that they still feel worse than before the disease. Mean EQ-VAS scores were 64.83 vs. 73.34 before infection. The persistent symptoms are more frequent in older patients and those with greater comorbidity. Conclusions: Persistent symptoms of post-COVID-19 syndrome are present in the majority of KTR, which highlights the need for long-term follow-up as well as diagnostic and rehabilitation programs.

Discrepancy between self-perceived mycophenolic acid-associated diarrhea and stool water content after kidney transplantation

BACKGROUND

Diarrhea is a well-known side effect of mycophenolic acid (MPA) use in kidney transplant recipients (KTRs). It is unknown whether self-reported diarrhea using the Modified Transplant Symptom Occurrence and Symptom Distress Scale (MTSOSD-59R) corresponds to stool water content and how both relate to MPA usage.

METHODS

MTSOSD-59R questionnaires filled out by 700 KTRs from the TransplantLines Biobank and Cohort Study (NCT03272841) were analyzed and compared with stool water content. Stool samples (N = 345) were freeze-dried, and a water content ≥80% was considered diarrhea.

RESULTS

Self-perceived diarrhea was reported by 46%, while stool water content ≥80% was present in 23% of KTRs. MPA use was not associated with self-perceived diarrhea (odds ratio(OR) 1.32; 95% confidence interval(CI), 0.87-1.99, p = .2), while it was associated with stool water content ≥80% (OR 2.88; 95%CI, 1.41-5.89, p = .004), independent of potential confounders. Adjustment for prior MPA discontinuation because of severe diarrhea, uncovered an association between MPA use and self-perceived diarrhea (OR 1.80; 95%CI, 1.13-2.89, p = .01).

CONCLUSIONS

These results suggest that reporting bias could add to the discrepancy between both methods for diarrhea assessment. We recommend use of objective biomarkers or more extensive questionnaires which assess information on stool frequency and stool consistency, to investigate post-transplantation diarrhea.

Gastrointestinal complications after kidney transplantation

Gastrointestinal complications are common after renal transplantation, and they have a wide clinical spectrum, varying from diarrhoea to post-transplant inflammatory bowel disease (IBD). Chronic immunosuppression may increase the risk of post-transplant infection and medication-related injury and may also be responsible for IBD in kidney transplant re-cipients despite immunosuppression. Differentiating the various forms of post-transplant colitis is challenging, since most have similar clinical and histological features. Drug-related colitis are the most frequently encountered colitis after kidney transplantation, particularly those related to the chronic use of mycophenolate mofetil, while de novo IBDs are quite rare. This review will explore colitis after kidney transplantation, with a particular focus on different clinical and histological features, attempting to clearly identify the right treatment, thereby improving the final outcome of patients.

Uremic and Post-Transplant Gastropathy in Patients With Chronic Kidney Disease and End-Stage Renal Disease

Gastrointestinal (GI) mucosal lesions are common in chronic kidney disease (CKD), end-stage renal disease (ESRD), and in post-renal transplant period. However, etiology of mucosal lesions pre- and post-transplant is very different. Gastropathy in non-transplant ESRD patients usually develops because of uremia, chronic anemia, and fluctuations in the gastric blood supply during hemodialysis, eventually leading to uremic gastritis. Gastropathy in post-transplant patients tends to be associated with immunosuppressive therapies. Helicobacter pylori infection is more prevalent in uremic patients than in post-transplant patients. Uremia can also lead to uremic arteriolopathy and autonomic nervous system dysfunction, which can present with GI symptoms mimicking uremic gastropathy. Post-transplantation immunosuppressive therapies have been linked to GI mucosal lesions as well. These lesions carry a poor prognostic factor disrupting the function of the GI tract, which in turn affects the pharmacokinetics of the immunosuppressive drugs eventually leading to poor graft survival and increased mortality. Mycophenolate mofetil is one of the agents more associated with intestinal erosions. Recognizing uremic gastropathy and intervening early helps prevent post-transplant GI complications. Acid controlling therapies can be an effective prophylaxis against both gastropathies. Using enteric-coated formulation for immunosuppressive agents may slow down the mucosal insult. Treatment of H. pylori in both patient populations may help prevent further mucosal injury. Lastly, timely screening for symptoms may help start treatment early and prevent progression to serious gastropathy.

Weight Gain, Energy Intake, Energy Expenditure, and Immunosuppressive Therapy in Kidney Transplant Recipients

BACKGROUND

Weight gain after kidney transplantation is a common health problem. The factors in weight gain after kidney transplant include many factors such as age, ethnicity, gender, change in lifestyle (eg, kilocalorie intake and physical activity level), and immunosuppressive therapy.

RESEARCH QUESTIONS

This study aimed to evaluate the relationship between weight gain and energy intake in dietary, energy expenditure in physical activity, and immunosuppressive therapy in kidney transplant recipients.

DESIGN

This prospective, observational study included 51 participants who underwent kidney transplant, during 6 months from the start of the study. Anthropometric measurements were performed at first week, third- and sixth-month follow-ups of transplant recipients. Participants also completed 3-day "Dietary Record Form" and the "Physical Activity Record Form" at each follow-up. Simple frequency, analysis of variance analysis, and correlation analysis were used for data analysis.

RESULTS

Weight gain in sixth month follow-up compared to baseline value was positively related to energy intake in first week (r = 0.59), third month (r = 0.75), and sixth month (r = 0.67) follow-ups, and energy expenditure in first week (r = 0.35) and sixth month (r = 0.34) follow-ups. However, weight gain was negatively related to mycophenolate mofetil dose (mg/d) in sixth month (r = -0.31) follow-up (P < .05).

DISCUSSION

The results of this study provide an opportunity to reflect and discuss on modifiable risk factors such as energy intake and energy expenditure that affect weight gain posttransplantation in participants. It also examines the relationship between immunosuppressive therapy. Additionally, these results can be effective in designing interventions and managing risk factors to achieve weight management goals.

The relationship between Helicobacter pylori and chronic kidney disease: update 2020

A number of studies has confirmed that the epidemiology of Helicobacter pylori is changing worldwide, with a decrease especially in developed countries. Nevertheless, since this gram-negative bacterium infects almost 50% of the world's population, it remains a global problem. Beyond its role in the pathogenesis of the main gastroduodenal diseases, including gastritis, peptic ulcer and gastric cancer, Helicobacter pylori has been suspected to be involved in several extra-gastroduodenal disorders. Patients with chronic kidney disease (CKD) present gastric mucosal injuries and dyspepsia more often than the general population. However, the reported relationship between CKD and Helicobacter pylori infection is conflicting. In fact, in this population these conditions have a multifactorial pathogenesis and Helicobacter pylori infection could play a limited role in their development. Nevertheless, while it seems that the prevalence of the bacterium is lower in patients with CKD than in controls, Helicobacter pylori has been shown to be associated to an increased occurrence of proteinuria in patients with type 2 diabetes mellitus. This narrative review analyzes the results of recent literature in this field with particular focus on data reported by meta-analyses.

Pharmacologic Treatment of Transplant Recipients Infected With SARS-CoV-2: Considerations Regarding Therapeutic Drug Monitoring and Drug-Drug Interactions

COVID-19 is a novel infectious disease caused by the severe acute respiratory distress (SARS)-coronavirus-2 (SARS-CoV-2). Several therapeutic options are currently emerging but none with universal consensus or proven efficacy. Solid organ transplant recipients are perceived to be at increased risk of severe COVID-19 because of their immunosuppressed conditions due to chronic use of immunosuppressive drugs (ISDs). It is therefore likely that solid organ transplant recipients will be treated with these experimental antivirals.