Nitric Oxide and Acute Phase Proteins Are Involved in Pathogenesis of Mycophenolate Mofetil–Induced Gastrointestinal Disorders in Rats

Large animal models for cardiac remuscularization studies: A methodological review

Myocardial infarction is the most common cause of heart failure, one of the most fatal non-communicable diseases worldwide. The disease could potentially be treated if the dead, ischemic heart tissues are regenerated and replaced with viable and functional cardiomyocytes. Pluripotent stem cells have proven the ability to derive specific and functional cardiomyocytes in large quantities for therapy. To test the remuscularization hypothesis, the strategy to model the disease in animals must resemble the pathophysiological conditions of myocardial infarction as in humans, to enable thorough testing of the safety and efficacy of the cardiomyocyte therapy before embarking on human trials. Rigorous experiments and in vivo findings using large mammals are increasingly important to simulate clinical reality and increase translatability into clinical practice. Hence, this review focus on large animal models which have been used in cardiac remuscularization studies using cardiomyocytes derived from human pluripotent stem cells. The commonly used methodologies in developing the myocardial infarction model, the choice of animal species, the pre-operative antiarrhythmics prophylaxis, the choice of perioperative sedative, anaesthesia and analgesia, the immunosuppressive strategies in allowing xenotransplantation, the source of cells, number and delivery method are discussed.

Intractable ascites associated with mycophenolate in a simultaneous kidney-pancreas transplant patient: a case report

Background

Mycophenolic acid (MPA), either given as an ester pro-drug or as an enteric-coated sodium salt, is the most commonly prescribed anti-proliferative immunosuppressive agent used following organ transplantation and widely applied in immune-mediated diseases. Clinicians are well aware of common adverse reactions related to MPA treatment, in particular diarrhea, leukopenia and infections. Here we report a case of severe, persistent ascites associated with MPA treatment. The otherwise unexplained and intractable ascites, requiring repeated paracenteses for more than 8 months, rapidly ceased with stopping the MPA treatment. To our knowledge this is the first case of severe ascites associated with MPA treatment reported in the scientific literature.

Case Presentation

A 45-year old female with type 1 diabetes mellitus received a simultaneous kidney-pancreas transplant. The surgery was uneventful. However, post-operatively she developed severe transudative ascites requiring in total more than 40 paracenteses treatments draining in the average 2.8 l of ascites fluid. The ascites formation persisted despite exclusion of a surgical complication, fully functioning kidney and pancreas allografts, lack of any significant proteinuria, normalization of circulating albumin levels, intensive use of diuretics and deliberate attempts to increase the intervals between the paracentesis treatments. Various differential diagnoses, including infectious, hepatic, vascular and cardiac causes were ruled out. Nine months after surgery enteric-coated mycophenolate sodium was switched to azathioprine after which ascites completely resolved. When mycophenolate was recommenced abdominal fullness and weight gain reoccurred. The patient had to be switched to long-term azathioprine treatment. More than 1 year post-conversion the patient remains free of ascites.

Conclusion

MPA is the most widely used antimetabolite immunosuppressive agent. We suggest to consider MPA treatment in the differential diagnosis of severe and unexplained ascites in transplant and non-transplant patients.

Drug-induced inflammatory bowel disease and IBD-like conditions

The pathogenesis of inflammatory bowel disease (IBD) is multifactorial and results from an interaction between genetic, immunologic, microbial, and environmental factors. Certain drugs could act as a trigger for the disease and have been implicated in the development of new onset IBD in a number a studies. These relationships are based on case reports and cohort studies, as proving this in the context of randomized controlled trials would be difficult. Drugs that have been linked to causing or worsening IBD include isotretinoin, antibiotics, nonsteroidal antiinflammatory drugs, oral contraceptives, mycophenolate mofetil, etanercept, ipilimumab, and rituximab. Bowel preparation for colonoscopy has also been associated with aphthoid lesions that may be confused with IBD. However, given the source of these reports we have to be cautious in the interpretation of the data before concluding that these drugs trigger IBD and what is being observed is not related to other confounding factors. Different pathogenic mechanisms have been suggested for the different drugs listed above. In order to clarify the confusion a comprehensive literature review was performed with the goal of advancing the knowledge on this subject.