Central nervous system toxicity after liver transplantation. The role of cyclosporine and cholesterol

Depression proteomic profiling in adolescents with transcriptome analyses in independent cohorts

Introduction

Depression is a major global burden with unclear pathophysiology and poor treatment outcomes. Diagnosis of depression continues to rely primarily on behavioral rather than biological methods. Investigating tools that might aid in diagnosing and treating early-onset depression is essential for improving the prognosis of the disease course. While there is increasing evidence of possible biomarkers in adult depression, studies investigating this subject in adolescents are lacking.

Methods

In the current study, we analyzed protein levels in 461 adolescents assessed for depression using the Development and Well-Being Assessment (DAWBA) questionnaire as part of the domestic Psychiatric Health in Adolescent Study conducted in Uppsala, Sweden. We used the Proseek Multiplex Neuro Exploratory panel with Proximity Extension Assay technology provided by Olink Bioscience, followed by transcriptome analyses for the genes corresponding to the significant proteins, using four publicly available cohorts.

Results

We identified a total of seven proteins showing different levels between DAWBA risk groups at nominal significance, including RBKS, CRADD, ASGR1, HMOX2, PPP3R1, CD63, and PMVK. Transcriptomic analyses for these genes showed nominally significant replication of PPP3R1 in two of four cohorts including whole blood and prefrontal cortex, while ASGR1 and CD63 were replicated in only one cohort.

Discussion

Our study on adolescent depression revealed protein-level and transcriptomic differences, particularly in PPP3R1, pointing to the involvement of the calcineurin pathway in depression. Our findings regarding PPP3R1 also support the role of the prefrontal cortex in depression and reinforce the significance of investigating prefrontal cortex-related mechanisms in depression.

Tacrolimus-induced Central Pontine Myelinolysis in a Pediatric Liver Transplant Recipient

Central pontine myelinolysis (CPM) is a rare neurological complication reported in liver transplant recipients. A 16-year-old boy with Wilson disease underwent a living donor liver transplant for acute-on-chronic liver failure. On postoperative day 7, he was noted to have diplopia, dysphagia, and bilateral lower limb weakness with wide base gait with gradual progression to akinetic mutism. Magnetic resonance imaging (MRI) brain was performed which was suggestive of CPM, and it was attributed to tacrolimus. We stopped tacrolimus, and he was started on ciclosporin. His neurological symptoms started improving after 72 hours and he had a complete clinical recovery by 6 weeks. Repeat MRI brain at 16 weeks after liver transplantation showed complete radiological resolution of the pontine lesion.

Treatment with the calcineurin inhibitor and immunosuppressant cyclosporine A impairs sensorimotor gating in Dark Agouti rats

RATIONALE

Calcineurin is a protein regulating cytokine expression in T lymphocytes and calcineurin inhibitors such as cyclosporine A (CsA) are widely used for immunosuppressive therapy. It also plays a functional role in distinct neuronal processes in the central nervous system. Disturbed information processing as seen in neuropsychiatric disorders is reflected by deficient sensorimotor gating, assessed as prepulse inhibition (PPI) of the acoustic startle response (ASR).

OBJECTIVE

Patients who require treatment with immunosuppressive drugs frequently display neuropsychiatric alterations during treatment with calcineurin inhibitors. Importantly, knockout of calcineurin in the forebrain of mice is associated with cognitive impairments and symptoms of schizophrenia-like psychosis as seen after treatment with stimulants.

METHODS

The present study investigated in rats effects of systemic acute and subchronic administration of CsA on sensorimotor gating. Following a single injection with effective doses of CsA, adult healthy male Dark Agouti rats were tested for PPI. For subchronic treatment, rats were injected daily with the same doses of CsA for 1 week before PPI was assessed. Since calcineurin works as a modulator of the dopamine pathway, activity of the enzyme tyrosine hydroxylase was measured in the prefrontal cortex and striatum after accomplishment of the study.

RESULTS

Acute and subchronic treatment with the calcineurin inhibitor CsA disrupted PPI at a dose of 20 mg/kg. Concomitantly, following acute CsA treatment, tyrosine hydroxylase activity was reduced in the prefrontal cortex, which suggests that dopamine synthesis was downregulated, potentially reflecting a stimulatory impact of CsA on this neurotransmitter system.

CONCLUSIONS

The results support experimental and clinical evidence linking impaired calcineurin signaling in the central nervous system to the pathophysiology of neuropsychiatric symptoms. Moreover, these findings suggest that therapy with calcineurin inhibitors may be a risk factor for developing neurobehavioral alterations as observed after the abuse of psychomotor stimulant drugs.

Genetic Approach to Elucidate the Role of Cyclophilin D in Traumatic Brain Injury Pathology

Cyclophilin D (CypD) has been shown to play a critical role in mitochondrial permeability transition pore (mPTP) opening and the subsequent cell death cascade. Studies consistently demonstrate that mitochondrial dysfunction, including mitochondrial calcium overload and mPTP opening, is essential to the pathobiology of cell death after a traumatic brain injury (TBI). CypD inhibitors, such as cyclosporin A (CsA) or NIM811, administered following TBI, are neuroprotective and quell neurological deficits. However, some pharmacological inhibitors of CypD have multiple biological targets and, as such, do not directly implicate a role for CypD in arbitrating cell death after TBI. Here, we reviewed the current understanding of the role CypD plays in TBI pathobiology. Further, we directly assessed the role of CypD in mediating cell death following TBI by utilizing mice lacking the CypD encoding gene Ppif. Following controlled cortical impact (CCI), the genetic knockout of CypD protected acute mitochondrial bioenergetics at 6 h post-injury and reduced subacute cortical tissue and hippocampal cell loss at 18 d post-injury. The administration of CsA following experimental TBI in Ppif-/- mice improved cortical tissue sparing, highlighting the multiple cellular targets of CsA in the mitigation of TBI pathology. The loss of CypD appeared to desensitize the mitochondrial response to calcium burden induced by TBI; this maintenance of mitochondrial function underlies the observed neuroprotective effect of the CypD knockout. These studies highlight the importance of maintaining mitochondrial homeostasis after injury and validate CypD as a therapeutic target for TBI. Further, these results solidify the beneficial effects of CsA treatment following TBI.

Neurologic Toxicities Associated with Tumor Necrosis Factor Inhibitors and Calcineurin Inhibitors

The calcineurin inhibitors cyclosporine and tacrolimus are used for their immunosuppressive effects. Neurotoxic side effects include tremor, paresthesia, and headache. Rarer neurotoxicities include seizure, posterior reversible encephalopathy syndrome, and encephalopathy. Tacrolimus tends to be more neurotoxic than cyclosporine. Management of toxicities associated with calcineurin inhibitors includes dose reduction, switching between calcineurin inhibitors, or switching to a calcineurin-free regimen. Tumor necrosis factor (TNF) inhibitors are used in autoimmune diseases. Management of demyelinating conditions among patients treated with anti-TNF should follow standard of care and withdrawal of the anti-TNF. This drug class should be avoided in patients with a history of demyelinating conditions.

Noninfectious neurologic complications of hematopoietic cell transplantation: A systematic review

OBJECTIVE/BACKGROUND

Neurological complications occur at a high frequency after hematopoietic cell transplantation (HCT). However, an absence is noted in the published literature as regards the quantification of the exact burden and the outcomes thereof. In this systematic review, we endeavored to detail if the recipients of HCT developed any noninfectious neurological events/complications.

METHODS

According to the PICO criteria, medical literature was searched. Complications that were evaluated included: stroke, peripheral neuropathy, myasthenia gravis, seizures, and posterior reversible encephalopathy syndrome. After strictly defining relevant variables and parameters, data from 173 eligible articles were then extracted accordingly, from the full text for each, for quantitative analysis; additionally, two American Society of Hematology conference abstracts were also subject to data extraction.

RESULTS

As is evident from the results of the data analysis, an increased frequency of these complications was seen in the HCT recipient population in comparison to the general population. The relative risk ranged from 1.33× to 142× depending on the complication studied.

CONCLUSION

These findings demonstrate that the recipients of HCT had a significantly higher risk of neurological complications and that their early recognition can enhance the monitoring of HCT survivors for the early developmental signs of neurological toxicity. This would facilitate timely interventions, thus ensuring a better quality of life.

Recent Topics on The Mechanisms of Immunosuppressive Therapy-Related Neurotoxicities

Although transplantation procedures have been developed for patients with end-stage hepatic insufficiency or other diseases, allograft rejection still threatens patient health and lifespan. Over the last few decades, the emergence of immunosuppressive agents such as calcineurin inhibitors (CNIs) and mammalian target of rapamycin (mTOR) inhibitors have strikingly increased graft survival. Unfortunately, immunosuppressive agent-related neurotoxicity commonly occurs in clinical practice, with the majority of neurotoxicity cases caused by CNIs. The possible mechanisms through which CNIs cause neurotoxicity include increasing the permeability or injury of the blood–brain barrier, alterations of mitochondrial function, and alterations in the electrophysiological state. Other immunosuppressants can also induce neuropsychiatric complications. For example, mTOR inhibitors induce seizures, mycophenolate mofetil induces depression and headaches, methotrexate affects the central nervous system, the mouse monoclonal immunoglobulin G2 antibody (used against the cluster of differentiation 3) also induces headaches, and patients using corticosteroids usually experience cognitive alteration. Therapeutic drug monitoring, individual therapy based on pharmacogenetics, and early recognition of symptoms help reduce neurotoxic events considerably. Once neurotoxicity occurs, a reduction in the drug dosage, switching to other immunosuppressants, combination therapy with drugs used to treat the neuropsychiatric manifestation, or blood purification therapy have proven to be effective against neurotoxicity. In this review, we summarize recent topics on the mechanisms of immunosuppressive drug-related neurotoxicity. In addition, information about the neuroprotective effects of several immunosuppressants is also discussed.

Thrombotic Microangiopathy of the Miscellaneous Secondary Type Responding to Plasma Exchange in a Liver Transplant Recipient

A thrombotic microangiopathy syndrome, clinically and pathologically similar to thrombotic thrombocytopenic purpura (TTP) has been reported in recipients of tissue transplants, including renal and bone marrow allografts. The diagnosis is made only after other causes of microangiopathic hemolytic anemia have been excluded. In this case report we present the outcome of the combination of plasma exchange, dipyridamole and aspirin in the management of a TTP-like syndrome that complicated the post-operative course of liver transplantation.

Repeated Systemic Treatment with Rapamycin Affects Behavior and Amygdala Protein Expression in Rats

BACKGROUND

Clinical data indicate that therapy with small-molecule immunosuppressive drugs is frequently accompanied by an incidence rate of neuropsychiatric symptoms. In the current approach, we investigated in rats whether repeated administration of rapamycin, reflecting clinical conditions of patients undergoing therapy with this mammalian target of rapamycin inhibitor, precipitates changes in neurobehavioral functioning.

METHODS

Male adult Dark Agouti rats were daily treated with i.p. injections of rapamycin (1, 3 mg/kg) or vehicle for 8 days. On days 6 and 7, respectively, behavioral performance in the Elevated Plus-Maze and the Open-Field Test was evaluated. One day later, amygdala tissue and blood samples were taken to analyze protein expression ex vivo.

RESULTS

The results show that animals treated with rapamycin displayed alterations in Elevated Plus-Maze performance with more pronounced effects in the higher dose group. Besides, an increase in glucocorticoid receptor density in the amygdala was seen in both treatment groups even though p-p70 ribosomal S6 kinase alpha, a marker for mammalian target of rapamycin functioning, was not affected. Protein level of the neuronal activity marker c-Fos was again only elevated in the higher dose group. Importantly, effects occurred in the absence of acute peripheral neuroendocrine changes.

CONCLUSIONS

Our findings indicate that anxiety-related behavior following rapamycin treatment was not directly attributed to mTOR-dependent mechanisms or stress but rather due to hyperexcitability of the amygdala together with glucocorticoid receptor-regulated mechanism(s) in this brain region. Together, the present results support the contention that subchronic treatment with rapamycin may induce neurobehavioral alterations in healthy, naive subjects. We here provide novel insights in central effects of systemic rapamycin in otherwise healthy subjects but also raise the question whether therapy with this drug may have detrimental effects on patients' neuropsychological functioning during immune therapy.

The safety of non-biological treatments in Ulcerative Colitis

INTRODUCTION

Ulcerative colitis (UC) is a chronic inflammatory bowel disease with a relapsing-remitting course that determines significant morbidity and can associate with local complications and/or extra-intestinal manifestations. Pharmacological therapies are often required for a lifetime with possible risks of toxicity and side effects. Areas covered: Non-biological therapies (i.e. aminosalicylates, corticosteroids and immunosuppressive drugs) are widely used in UC patients for controlling the active phases of the disease and maintaining remission. Expert Opinion: Aminosalycilates have a good safety profile with a low risk of idiosyncrasic reactions. In contrast, the use of corticosteroids and immunosuppressive drugs can associate with unacceptable side effects, some of which are potentially life threatening. Mechanisms underlying the development of these side effects are not fully understood and strategies aimed to prevent them have not yet been standardized. However, clinicians should monitor the patients during therapy to recognize the adverse events at an early stage of the occurrence. New drugs that selectively target molecules involved in the amplification of the ongoing mucosal inflammation are currently under investigation. Preliminary data indicate that such compounds have better overall safety and tolerability than corticosteroids and immunosuppressive drugs.

Posterior Reversible Encephalopathy Syndrome: A Review

Radiologists may be the first to suggest the diagnosis of posterior reversible encephalopathy syndrome (PRES). PRES is associated with many diverse clinical entities, the most common of which are eclampsia, hypertension, and immunosuppressive treatment. Radiologists should be aware of the spectrum of imaging findings in PRES. When promptly recognized and treated, the symptoms and radiological abnormalities can be completely reversed. When unrecognized, patients can progress to ischemia, massive infarction, and death. In this review, we present an overview of the unique signs observed on computed tomography and magnetic resonance images in PRES that can help in the early diagnosis and treatment that is highly effective in this syndrome.

Imaging spectrum of central nervous system complications of hematopoietic stem cell and solid organ transplantation

Neurologic complications are common after hematopoietic stem cell transplantation (HSCT) and solid organ transplantation (SOT) and affect 30-60% of transplant recipients. The aim of this article is to provide a practical imaging approach based on the timeline and etiology of CNS abnormalities, and neurologic complications related to transplantation of specific organs. The lesions will be classified based upon the interval from HSCT procedure: pre-engraftment period <30 days, early post-engraftment period 30-100 days, late post-engraftment period >100 days, and the interval from SOT procedure: postoperative phase 1-4 weeks, early posttransplant syndromes 1-6 months, late posttransplant syndromes >6 months. Further differentiation will be based on etiology: infections, drug toxicity, metabolic derangements, cerebrovascular complications, and posttransplantation malignancies. In addition, differentiation will be based on complications specific to the type of transplantation: allogeneic and autologous hematopoietic stem cells (HSC), heart, lung, kidney, pancreas, and liver. Thus, in this article we emphasize the strategic role of neuroradiology in the diagnosis and response to treatment by utilizing a methodical approach in the work up of patients with neurologic complications after transplantation.

Neurological Complications of Respiratory Disease

The respiratory and central nervous systems are intimately connected. Ventilatory control is strictly regulated by central mechanisms in a complex process that involves central and peripheral chemoreceptors, baroreceptors, the cardiovascular system, and specific areas of the brain responsible for autonomic control. Disorders of the lung and respiratory system can interfere with these mechanisms and temporarily or permanently disrupt this complex network resulting in mild to severe neurological sequelae. This article explores the wide variety of neurological problems resulting from respiratory dysfunction, with emphasis on its pathophysiology, clinical features, prognosis, and long-term outcome.

Neurologic complications of transplantation

Major neurologic morbidity, such as seizures and encephalopathy, complicates 20-30% of organ and stem cell transplantation procedures. The majority of these disorders occur in the early posttransplant period, but recipients remain at risk for opportunistic infections and other nervous system disorders for many years. These long-term risks may be increasing as acute survival increases, and a greater number of "sicker" patients are exposed to long-term immunosuppression. Drug neurotoxicity accounts for a significant proportion of complications, with posterior reversible leukoencephalopathy syndrome, primarily associated with calcineurin inhibitors (i.e., cyclosporine and tacrolimus), being prominent as a cause of seizures and neurologic deficits. A thorough evaluation of any patient who develops neurologic symptoms after transplantation is mandatory, since reversible and treatable conditions could be found, and important prognostic information can be obtained.

Neurologic Complications after Allogeneic Hematopoietic Stem Cell Transplantation

Neurologic complications after hematopoietic stem cell transplantation are frequently life-threatening, and their clinical management can be highly challenging. A wide spectrum of causative factors-including drug-related toxicities; infections sustained by virus, bacteria, or invasive molds; metabolic encephalopathy; cerebrovascular disorders; immune-mediated disorders; and disease recurrence-may lead to potentially lethal complications. Moreover, given that some neurologic complications are not uncommonly diagnosed post mortem, their overall incidence is likely to be underestimated. Their prompt recognition and timely treatment are of paramount importance to reduce the risk for transplantation-related death.

Cyclosporine Treatment in Traumatic Brain Injury: Operation Brain Trauma Therapy

Operation Brain Trauma Therapy (OBTT) is a consortium of investigators using multiple pre-clinical models of traumatic brain injury (TBI) to bring acute therapies to clinical trials. To screen therapies, we used three rat models (parasagittal fluid percussion injury [FPI], controlled cortical impact [CCI], and penetrating ballistic-like brain injury [PBBI]). We report results of the third therapy (cyclosporin-A; cyclosporine; [CsA]) tested by OBTT. At each site, rats were randomized to treatment with an identical regimen (TBI + vehicle, TBI + CsA [10 mg/kg], or TBI + CsA [20 mg/kg] given intravenously at 15 min and 24 h after injury, and sham). We assessed motor and Morris water maze (MWM) tasks over 3 weeks after TBI and lesion volume and hemispheric tissue loss at 21 days. In FPI, CsA (10 mg/kg) produced histological protection, but 20 mg/kg worsened working memory. In CCI, CsA (20 mg/kg) impaired MWM performance; surprisingly, neither dose showed benefit on any outcome. After PBBI, neither dose produced benefit on any outcome, and mortality was increased (20 mg/kg) partly caused by the solvent vehicle. In OBTT, CsA produced complex effects with histological protection at the lowest dose in the least severe model (FPI), but only deleterious effects as model severity increased (CCI and PBBI). Biomarker assessments included measurements of glial fibrillary acidic protein (GFAP) and ubiquitin C-terminal hydrolase-L1 (UCH-L1) in blood at 4 or 24 h after injury. No positive treatment effects were seen on biomarker levels in any of the models, whereas significant increases in 24 h UCH-L1 levels were seen with CsA (20 mg/kg) after CCI and 24 h GFAP levels in both CsA treated groups in the PBBI model. Lack of behavioral protection in any model, indicators of toxicity, and a narrow therapeutic index reduce enthusiasm for clinical translation.

Synaptic Mitochondria Sustain More Damage than Non-Synaptic Mitochondria after Traumatic Brain Injury and Are Protected by Cyclosporine A

Currently, there are no Food and Drug Administration (FDA)-approved pharmacotherapies for the treatment of those with traumatic brain injury (TBI). As central mediators of the secondary injury cascade, mitochondria are promising therapeutic targets for prevention of cellular death and dysfunction after TBI. One of the most promising and extensively studied mitochondrial targeted TBI therapies is inhibition of the mitochondrial permeability transition pore (mPTP) by the FDA-approved drug, cyclosporine A (CsA). A number of studies have evaluated the effects of CsA on total brain mitochondria after TBI; however, no study has investigated the effects of CsA on isolated synaptic and non-synaptic mitochondria. Synaptic mitochondria are considered essential for proper neurotransmission and synaptic plasticity, and their dysfunction has been implicated in neurodegeneration. Synaptic and non-synaptic mitochondria have heterogeneous characteristics, but their heterogeneity can be masked in total mitochondrial (synaptic and non-synaptic) preparations. Therefore, it is essential that mitochondria targeted pharmacotherapies, such as CsA, be evaluated in both populations. This is the first study to examine the effects of CsA on isolated synaptic and non-synaptic mitochondria after experimental TBI. We conclude that synaptic mitochondria sustain more damage than non-synaptic mitochondria 24 h after severe controlled cortical impact injury (CCI), and that intraperitoneal administration of CsA (20 mg/kg) 15 min after injury improves synaptic and non-synaptic respiration, with a significant improvement being seen in the more severely impaired synaptic population. As such, CsA remains a promising neuroprotective candidate for the treatment of those with TBI.

Posterior Reversible Encephalopathy Syndrome: Local Experience From Saudi Arabia

OBJECTIVES

Posterior reversible encephalopathy syndrome (PRES) is a clinicoradiological syndrome characterized by headache, altered mental status, seizures, or loss of vision. In this study, we report the largest series of PRES coming from Saudi Arabia and explore the etiology, clinical presentation, and outcome. We also report new imaging findings associated with this condition.

METHODS

We performed a retrospective study of all cases of PRES admitted to King Abdulaziz Medical City, Jeddah, Saudi Arabia, between the years 2005 and 2015. A neurologist reviewed all charts and analyzed the clinical presentations, etiological factors, and outcomes, and a neuroradiologist reviewed the imaging studies. Only patients with clinical and imaging features consistent with PRES were included in the study.

RESULTS

We collected 31 patients who had clinical and radiological features consistent with PRES. Females were more affected than males (18 females and 13 males), and patients' age ranged from 6 to 95 years, with a mean of 38.3 years. Patients were treated by removing the precipitating causes and treating the underlying conditions. Resolution of neurologic signs occurred within 2 to 3 weeks in all patients.

CONCLUSION

In our opinion, PRES itself is usually a benign condition with complete recovery if the condition is recognized early and managed appropriately. Although clinical signs are nonspecific, the constellation of symptoms including headache, visual problems, seizures, and altered level of consciousness should suggest the possibility of PRES, especially in high-risk group. Abnormalities on magnetic resonance imaging are often characteristic and may be the first clue to the diagnosis.

Neurologic Complications of Commonly Used Drugs in the Hospital Setting

This chapter reviews the neurologic complications of medications administered in the hospital setting, by class, introducing both common and less common side effects. Detail is devoted to the interaction between pain, analgesia, sedation, and their residual consequences. Antimicrobials are given in nearly every hospital setting, and we review their capacity to produce neurologic sequelae with special devotion to cefepime and the antiviral treatment of human immunodeficiency virus. The management of hemorrhagic stroke has become more complex with the introduction of novel oral anticoagulants, and we provide an update on what is known about reversal of the new oral anticoagulants. Both central and peripheral nervous system complications of immunosuppressants and chemotherapies are reviewed. Because diagnosis is generally based on clinical acumen, alone, neurotoxic syndromes resulting from psychotropic medications may be easily overlooked until severe dysautonomia develops. We include a practical approach to the diagnosis of serotonin syndrome and neuroleptic malignant syndrome.

Posterior Reversible Encephalopathy Syndrome in a Bone Marrow Transplant Patient: A Complication of Immunosuppressive Drugs?

Posterior reversible encephalopathy is a complex but well-recognized clinical and radiological entity associated with a variety of benign and malignant conditions including hypertensive encephalopathy, eclampsia, renal failure and immunosuppressive drugs. The pathogenesis is incompletely understood, although it seems to be related to the breakthrough of auto-regulation and endothelial dysfunction. The clinical syndromes typically involve headache, altered mental status, seizures, visual disturbance and other focal neurological signs and radiographically reversible vasogenic subcortical edema without infarction. Here, we report a case of posterior reversible encephalopathy syndrome in a patient with chronic myeloid leukemia who received allogenic bone marrow transplantation (allo-BMT) and immunosuppressive drugs.

Reprint of: Nutrition in the Management of Cirrhosis and its Neurological Complications

Malnutrition is a common feature of chronic liver diseases that is often associated with a poor prognosis including worsening of clinical outcome, neuropsychiatric complications as well as outcome following liver transplantation. Nutritional assessment in patients with cirrhosis is challenging owing to confounding factors related to liver failure. The objectives of nutritional intervention in cirrhotic patients are the support of liver regeneration, the prevention or correction of specific nutritional deficiencies and the prevention and/or treatment of the complications of liver disease per se and of liver transplantation. Nutritional recommendations target the optimal supply of adequate substrates related to requirements linked to energy, protein, carbohydrates, lipids, vitamins and minerals. Some issues relating to malnutrition in chronic liver disease remain to be addressed including the development of an appropriate well-validated nutritional assessment tool, the identification of mechanistic targets or therapy for sarcopenia, the development of nutritional recommendations for obese cirrhotic patients and liver-transplant recipients and the elucidation of the roles of vitamin A hepatotoxicity, as well as the impact of deficiencies in riboflavin and zinc on clinical outcomes. Early identification and treatment of malnutrition in chronic liver disease has the potential to lead to better disease outcome as well as prevention of the complications of chronic liver disease and improved transplant outcomes.

Neurobehavioral consequences of small molecule-drug immunosuppression

60 years after the first successful kidney transplantation in humans, transplant patients have decent survival rates owing to a broad spectrum of immunosuppressive medication available today. Not only transplant patients, but also patients with inflammatory autoimmune diseases or cancer benefit from these life-saving immunosuppressive and anti-proliferative medications. However, this success is gained with the disadvantage of neuropsychological disturbances and mental health problems such as depression, anxiety and impaired quality of life after long-term treatment with immunosuppressive drugs. So far, surprisingly little is known about unwanted neuropsychological side effects of immunosuppressants and anti-proliferative drugs from the group of so called small molecule-drugs. This is partly due to the fact that it is difficult to disentangle whether and to what extent the observed neuropsychiatric disturbances are a direct result of the patient's medical history or of the immunosuppressive treatment. Thus, here we summarize experimental as well as clinical data of mammalian and human studies, with the focus on selected small-molecule drugs that are frequently employed in solid organ transplantation, autoimmune disorders or cancer therapy and their effects on neuropsychological functions, mood, and behavior. These data reveal the necessity to develop immunosuppressive and anti-proliferative drugs inducing fewer or no unwanted neuropsychological side effects, thereby increasing the quality of life in patients requiring long term immunosuppressive treatment. This article is part of a Special Issue entitled 'Neuroimmunology and Synaptic Function'.

Posterior reversible encephalopathy syndrome

Posterior reversible encephalopathy syndrome (PRES) is a complex disorder, our understanding of which continues to evolve. PRES has many clinical associations, many causative factors, a variety of imaging manifestations, and its pathophysiology remains a topic of debate. There are also many other disorders that may mimic PRES. We present a concise review of PRES to enable the radiologist to more readily and easily recognize this treatable disorder with important clinical implications.

Short-term treatment with the calcineurin inhibitor cyclosporine A decreases HPA axis activity and plasma noradrenaline levels in healthy male volunteers

Treatment with the selective calcineurin inhibitor and immunosuppressive drug cyclosporine A (CsA) is associated with neurotoxicity and neurocognitive impairments. Whether and to what extent CsA is inducing alterations of the neuroendocrine status is unknown so far. Therefore, the present study investigated the effect of short-term CsA treatment on hypothalamus-pituitary-adrenal (HPA) axis activity and catecholamine release as well as state anxiety in healthy male subjects. Treatment with CsA significantly reduced plasma concentrations of adrenocorticotropic hormone (ACTH), cortisol, and noradrenaline whereas adrenaline levels and state anxiety remained unaffected. Future studies should analyze the mechanisms of CsA-induced effects on neuroendocrine variables, neurocognitive functions and mood.

Acute systemic rapamycin induces neurobehavioral alterations in rats

Rapamycin is a drug with antiproliferative and immunosuppressive properties, widely used for prevention of acute graft rejection and cancer therapy. It specifically inhibits the activity of the mammalian target of rapamycin (mTOR), a protein kinase known to play an important role in cell growth, proliferation and antibody production. Clinical observations show that patients undergoing therapy with immunosuppressive drugs frequently suffer from affective disorders such as anxiety or depression. However, whether these symptoms are attributed to the action of the distinct compounds remains rather elusive. The present study investigated in rats neurobehavioral consequences of acute rapamycin treatment. Systemic administration of a single low dose rapamycin (3mg/kg) led to enhanced neuronal activity in the amygdala analyzed by intracerebral electroencephalography and FOS protein expression 90min after drug injection. Moreover, behavioral investigations revealed a rapamycin-induced increase in anxiety-related behaviors in the elevated plus-maze and in the open-field. The behavioral alterations correlated to enhanced amygdaloid expression of KLK8 and FKBP51, proteins that have been implicated in the development of anxiety and depression. Together, these results demonstrate that acute blockade of mTOR signaling by acute rapamycin administration not only causes changes in neuronal activity, but also leads to elevated protein expression in protein kinase pathways others than mTOR, contributing to the development of anxiety-like behavior. Given the pivotal role of the amygdala in mood regulation, associative learning, and modulation of cognitive functions, our findings raise the question whether therapy with rapamycin may induce alterations in patients neuropsychological functioning.

Calcineurin downregulation in the amygdala is sufficient to induce anxiety-like and depression-like behaviors in C57BL/6J male mice

BACKGROUND

The calcium-dependent phosphatase calcineurin is highly expressed in the amygdala, a brain area important for behaviors related to mood disorders and anxiety. Organ transplant patients are administered the calcineurin inhibitor cyclosporine A (CsA) chronically and demonstrate an increased incidence of anxiety and mood disorders. It is therefore important to determine whether chronic blockade of calcineurin may contribute to symptoms of anxiety and depression in these patients.

METHODS

Pharmacological (CSA) and viral-mediated gene transfer (adeno-associated viral expression of short hairpin RNA [shRNA]) approaches were used to inhibit calcineurin activity systemically or selectively in the amygdala of the mouse brain to determine the role of calcineurin in behaviors related to anxiety and depression.

RESULTS

Systemic inhibition of calcineurin activity with CsA or local downregulation of calcineurin levels in the amygdala using adeno-associated viral-delivered shRNAs targeting calcineurin B increased measures of anxiety-like behavior in the elevated plus maze, the light/dark box, and the open field test. A decrease in locomotor activity was also observed in mice treated systemically with CsA. In the forced swim model of depression-like behavior, both systemic CsA treatment and shRNA-mediated calcineurin blockade in the amygdala significantly increased immobility.

CONCLUSIONS

Taken together, these data demonstrate that decreasing calcineurin activity in the amygdala increases anxiety-like behaviors and to some extent depression-like behaviors. These studies suggest that chronic administration of CsA to organ transplant patients could have significant effects on anxiety and mood and this should be recognized as a potential clinical consequence of treatment to prevent transplant rejection.

Nutrition in the management of cirrhosis and its neurological complications

Malnutrition is a common feature of chronic liver diseases that is often associated with a poor prognosis including worsening of clinical outcome, neuropsychiatric complications as well as outcome following liver transplantation. Nutritional assessment in patients with cirrhosis is challenging owing to confounding factors related to liver failure. The objectives of nutritional intervention in cirrhotic patients are the support of liver regeneration, the prevention or correction of specific nutritional deficiencies and the prevention and/or treatment of the complications of liver disease per se and of liver transplantation. Nutritional recommendations target the optimal supply of adequate substrates related to requirements linked to energy, protein, carbohydrates, lipids, vitamins and minerals. Some issues relating to malnutrition in chronic liver disease remain to be addressed including the development of an appropriate well-validated nutritional assessment tool, the identification of mechanistic targets or therapy for sarcopenia, the development of nutritional recommendations for obese cirrhotic patients and liver-transplant recipients and the elucidation of the roles of vitamin A hepatotoxicity, as well as the impact of deficiencies in riboflavin and zinc on clinical outcomes. Early identification and treatment of malnutrition in chronic liver disease has the potential to lead to better disease outcome as well as prevention of the complications of chronic liver disease and improved transplant outcomes.

Evolution of taxanes in the treatment of metastatic breast cancer

Taxanes have become effective therapies for patients with metastatic breast cancer (MBC); however, understanding the differences among them is important. Each of the taxanes currently approved for treating MBC has a unique formulation, which translates to differences in toxicity profiles and administration considerations. In this article, the rationale for the development of the taxanes paclitaxel, docetaxel, and nab-paclitaxel is reviewed from a historical perspective. The mechanisms of action, formulations, and indications of taxanes also are discussed. The impact of their formulations on clinical practice and patient care, particularly solvent-based versus novel solvent-free formulations, will be reviewed from the nursing perspective.

Neurological complications post-liver transplantation: impact of nutritional status

Nutritional status is significantly altered in patients with end-stage liver disease (cirrhosis). Malnutrition is a common complication of cirrhosis and is known to be associated with a greater risk of post-operative complications and mortality, especially following liver transplantation. Neurological complications occur frequently after transplant and the nature and extent of these complications may relate to nutritional deficits such as protein-calorie malnutrition as well as vitamin and micronutrient deficiencies. A consensus document from the International Society on Hepatic Encephalopathy and Nitrogen metabolism (ISHEN) has been established in order to address these concerns. Careful assessment of nutritional status followed by prompt treatment of nutritional deficits has the potential to impact on transplant outcome and, in particular, on post-transplant neurological disorders in patients with cirrhosis.

Neurologic complications in patients with inflammatory bowel disease: increasing relevance in the era of biologics

Extraintestinal manifestations of inflammatory bowel disease (IBD) can involve almost every organ system. Neurologic complications are not infrequent in patients with IBD, but are poorly recognized and underreported. Pathophysiologically, these may represent immune-mediated phenomenon, nonimmunologic complications due to micronutrient deficiencies, thromboembolism, or be medication-induced. Peripheral neuropathy is the most common neurologic complication of IBD and may be immune-mediated, or caused by therapy with anti-tumor necrosis factor-alpha (TNF-α) therapy or metronidazole. Multiple sclerosis occurs with a greater frequency in patients with IBD. Anti-TNF-α therapy can cause neurologic disease characterized by central demyelination that mimics multiple sclerosis. Hence, patients with a history of demyelinating diseases or with symptoms of polyneuropathy should be carefully evaluated before initiation of anti-TNF-α therapy. Natalizumab has been associated with fatal progressive multifocal leukoencephalopathy due to reactivation of JC virus, and occurs with greater frequency in patients with previous JC virus infection. Stroke secondary to venous or arterial thromboembolism can be seen in patients with active Crohn's disease. It is important for gastroenterologists to be aware of the neurologic complications in patients with IBD. Neurologic symptoms in these patients should be promptly evaluated.

Inhibition of calcineurin in the prefrontal cortex induced depressive-like behavior through mTOR signaling pathway

RATIONAL

Although it has been recognized that inhibition of calcineurin induced depressive-like behavior, the underlying neural mediators have not yet been identified. Mammalian target of rapamycin (mTOR), a serine/threonine protein kinase that regulates protein synthesis in synapses, has been demonstrated to be involved in the rapid antidepressant effects of ketamine.

OBJECTIVE

To investigate a potential role of mTOR signaling pathway which interferes with depressive-like behavior induced by calcineurin blockade and to determine the neurobiological mechanisms underlying mood-related disorders.

METHODS

Calcineurin inhibitor cyclosporine A (CsA) and tacrolimus (FK506) were microinjected into the medial prefrontal cortex (mPFC) in rats, and the depressive-like behavior was measured in sucrose preference test and forced swim test. Additionally, mTOR activity was tested by the levels of phosphorylation of p70s6 kinase (p70s6k) and 40S ribosomal protein S6 (rps6).

RESULTS

Chronic microinjection of CsA or FK506 into mPFC increased depressive-like behaviors and decreased mTOR activity, but acute CsA or FK506 had no effects on both behavioral phenotype and mTOR activity. Furthermore, activation of mTOR by NMDA reversed the depressive-like behavior induced by chronic CsA or FK506 administration. Moreover, inhibition of mTOR by rapamycin reversed the antidepressant effects of ketamine. Finally, traditional antidepressant venlafaxine prevented the depressive-like performance induced by chronic CsA or FK506 treatment.

CONCLUSION

These findings indicate that calcineurin-inhibition-induced depressive-like behavior is mediated by blockade of the mTOR signaling pathway and raise the possibility that stimulation of specific brain mTOR may be sufficient to decrease risk of affective disorders in patients treated with calcineurin inhibitor.

Drug choices in autoimmune hepatitis: part B--Nonsteroids

Nonsteroidal medications, previously unfamiliar in the management of autoimmune hepatitis, can supplement or replace conventional corticosteroid regimens, especially in problematic patients. Mycophenolate mofetil is a next-generation purine antagonist that has been useful in treating patients with azathioprine intolerance. It has been less effective in salvaging patients with steroid-refractory disease. Azathioprine is the choice as a corticosteroid-sparing agent in treatment-naive patients and in individuals with corticosteroid intolerance, incomplete response and relapse after drug withdrawal. Tacrolimus is preferred over cyclosporine for recalcitrant disease because of its established preference in organ transplantation, but replacement with cyclosporine should be considered if the disease worsens on treatment. Rapamycin has antiproliferative and proapoptotic actions that warrant further study in autoimmune hepatitis. The nonstandard, nonsteroidal medications are mainly salvage therapies with off-label indications that must be used in highly individualized and well-monitored clinical situations.

Catatonia as a manifestation of tacrolimus-induced neurotoxicity in organ transplant patients: a case series

Tacrolimus has been associated with severe neurotoxicity in organ transplant patients. Catatonia can be a rare manifestation of tacrolimus-induced neurotoxicity as we report two cases of catatonia in solid organ transplant patients on tacrolimus. Catatonic symptoms completely resolved in these patients after reducing the tacrolimus dosage or switching it to alternative immunosuppressants. Catatonia symptoms in organ transplant patients should alert clinicians to look for tacrolimus-induced neurotoxicity despite normal serum tacrolimus levels and neuroimaging findings.

Changing picture of central nervous system complications in liver transplant recipients

Central nervous system (CNS) complications are common after liver transplantation (LT). According to the literature, the most common causes are infections and the neurotoxicity of immunosuppressive drugs (cyclosporine and tacrolimus). The aim of this study was to evaluate the incidence, clinical presentations, etiologies, and outcomes of CNS complications in a series of 395 consecutive LT recipients whose immunosuppression regimen was designed for low tacrolimus blood levels. An analysis of the 12-hour trough concentrations of tacrolimus in the study population showed that the target drug levels, which were designed to maintain minimal immunosuppression, were usually achieved. In all, 64 patients (16.2%) developed major neurological symptoms (37 within 30 days of LT). None of the observed CNS complications were caused by infections (viral, bacterial, or fungal), and only 3 of the 395 patients (0.8%) received a diagnosis of tacrolimus-related leukoencephalopathy. Cerebrovascular disease was identified in 15 patients (3.8%; 8 had cerebral hemorrhages, 5 had ischemic strokes, and 2 had subdural hemorrhages). Pontine myelinolysis was found in 2 patients (0.5%). Notably, no clear cause was identified for the remaining 44 cases (11.1%): brain imaging was negative for 22 cases, and diffuse hypoxic changes were present for the other 22. CNS complications were significantly associated with a reduction in 3-month patient survival (88.8% versus 95.4%) and 5-year patient survival (57.3% versus 84.1%). Among the pretransplant variables that were analyzed, the incidence of portosystemic encephalopathy, the peak serum bilirubin levels, and the lowest serum total cholesterol levels were significantly different between the 64-patient group with CNS complications and the asymptomatic group of 331 patients.

Reversible posterior leukoencephalopathy syndrome: diagnosis and management in the setting of lung transplantation

Reversible posterior leukoencephalopathy syndrome (RPLS) is a potentially devastating early complication of calcineurin inhibitor (CNI) therapy in solid organ transplantation. Management centres on cessation of CNI therapy; however, this strategy is complicated in lung transplantation because of the threat of allograft rejection, or, if CNI is replaced with mammalian target of rapamycin-based immunosuppression, poor wound healing and bronchial dehiscence. We describe four cases of RPLS after lung transplantation, emphasizing the diagnostic and management approach required to maintain a healthy allograft and ensure that RPLS is, as the name suggests, reversible.

Analytic Review: Neurological Complications of Transplantation

Recipients of solid organ or hematopoietic cell transplants are at risk of life-threatening neurological disorders including encephalopathy, seizures, infections and tumors of the central nervous system, stroke, central pontine myelinolysis, and neuromuscular disorders—often requiring admission to, or occurring in, the intensive care unit (ICU). Many of these complications are linked directly or indirectly to immunosuppressive therapy. However, neurological disorders may also result from graft versus host disease, or be an expression of the underlying disease which prompted transplantation, as well as injury induced during radiation, chemotherapy, surgery, and ICU stay. In rare cases, neuroinfectious pathogens may be transmitted with the transplanted tissue or organ. Diagnosis may be a challenge because clinical symptoms and findings on neuroimaging lack specificity, and a biological specimen or tissue diagnosis is often needed for definitive diagnosis. Management is centered on preventing further neurological injury, etiology-targeted therapy, and balancing the benefits and toxicities of specific immunosuppressive agents.

Adverse drug reaction profile of nanoparticle versus conventional formulation of paclitaxel: An observational study

Objectives:

Conventional polyethoxylated castor oil (PCO)-based paclitaxel is associated with major adverse drug reactions (ADRs). Nanoxel, a nanoparticle-based formulation, may improve its tolerability by removing the need for PCO vehicle, and also permit its use in a higher dose. We conducted intensive monitoring of the ADR profile of Nanoxel in comparison with conventional paclitaxel in a public tertiary care set-up.

Materials and Methods:

ADR data were collected from 10 patients receiving Nanoxel and 10 age-matched controls receiving conventional paclitaxel in this longitudinal observational study, conducted in a medical oncology ward over 18 months. Severity was graded as per US National Cancer Institute Common Terminology Criteria for Adverse Events.

Results:

The groups had comparable demography at baseline. The median disease duration and per cycle median dose of paclitaxel were greater in the Nanoxel arm. Total 119 ADRs were noted with Nanoxel and 123 with conventional paclitaxel. Of these, 25 (21.0%, 95% CI 13.69–28.33%) in the Nanoxel and 20 (16.2%, 95% CI 9.74–22.78%) in paclitaxel group were of grade 3/4 severity. Common events included myalgia, nausea, anemia, paresthesia, alopecia, diarrhea, and vomiting with Nanoxel, and paresthesia, anemia, myalgia, anorexia, alopecia, vomiting, diarrhea, stomatitis, and nausea with paclitaxel. Of the less common events (<5%), grade 2 or 3 arthralgia was seen exclusively with Nanoxel while motor neuropathy with muscular weakness was more frequent and severe with conventional paclitaxel. Hypersensitivity reactions were not encountered in either arm, although no antiallergy premedication was employed for Nanoxel.

Conclusions:

Despite its ADR profile being statistically comparable to conventional paclitaxel, this observational study suggests that Nanoxel tolerability could be better, considering that a significantly higher dose was employed. This hypothesis needs confirmation through an interventional study.

Cyclosporin A--a review on fermentative production, downstream processing and pharmacological applications

In present times, the immunosuppressants have gained considerable importance in the world market. Cyclosporin A (CyA) is a cyclic undecapeptide with a variety of biological activities including immunosuppressive, anti-inflammatory, antifungal and antiparasitic properties. CyA is produced by various types of fermentation techniques using Tolypocladium inflatum. In the present review, we discuss the biosynthetic pathway, fermentative production, downstream processing and pharmacological activities of CyA.

Therapeutic window analysis of the neuroprotective effects of cyclosporine A after traumatic brain injury

Mitochondrial dysfunction plays a pivotal role in secondary cell death mechanisms following traumatic brain injury (TBI). Several reports have demonstrated that inhibition of the mitochondrial permeability transition pore with the immunosuppressant drug cyclosporine A (CsA) is efficacious. Accordingly, CsA is being moved forward into late-stage clinical trials for the treatment of moderate and severe TBI. However, several unknowns exist concerning the optimal therapeutic window for administering CsA at the proposed dosages to be used in human studies. The present study utilized a moderate (1.75 mm) unilateral controlled cortical impact model of TBI to determine the most efficacious therapeutic window for initiating CsA therapy. Rats were administered an IP dose of CsA (20 mg/kg) or vehicle at 1, 3, 4, 5, 6, and 8 h post-injury. Immediately following the initial IP dose, osmotic mini-pumps were implanted at these time points to deliver 10 mg/kg/d of CsA or vehicle. Seventy-two hours following the initiation of treatment the pumps were removed to stop CsA administration. Quantitative analysis of cortical tissue sparing 7 days post-injury revealed that CsA treatment initiated at any of the post-injury initiation times out to 8 h resulted in significantly less cortical damage compared to animals receiving vehicle treatment. However, earlier treatment begun in the first 3 h was significantly more protective than that begun at 4 and 8 h. Treatment initiated at 1 h post-injury (∼68% decrease) was not significantly different than that seen at 3 h (∼46% decrease), but resulted in significantly greater cortical tissue sparing compared to CsA treatment initiated at least 4 h post-injury (28% decrease). Together these results illustrate the importance of initiating therapeutic interventions such as CsA as soon as possible following TBI, preferably within 4 h post-injury, to achieve the best possible neuroprotective effect. However, the drug appears to retain some protective efficacy even when initiated as late as 8 h post-injury.

Posterior reversible encephalopathy syndrome

Posterior reversible encephalopathy syndrome (PRES) is characterized by headache, altered mental status, visual disturbances, and seizures. Radiological features typically include edema of the posterior cerebral regions, especially of the parietooccipital lobes. Atypical imaging features, such as involvement of anterior cerebral regions, deep white matter, and the brain stem are also frequently seen. Vasoconstriction is common in vascular imaging. Different conditions have been associated with PRES, but toxemia of pregnancy, solid organ or bone marrow transplantation, immunosuppressive treatment, cancer chemotherapy, autoimmune diseases, and hypertension are most commonly described. The pathophysiology of PRES is unclear and different hypotheses are being discussed. Posterior reversible encephalopathy syndrome is best managed by monitoring and treatment in the setting of a neurointensive care unit. The prognosis is usually benign with complete reversal of clinical symptoms within several days, when adequate treatment is immediately initiated. Treatment of severe hypertension, seizures, and withdrawal of causative agents represent the hallmarks of specific therapy in PRES. Delay in diagnosis and treatment may lead to permanent neurological sequelae. Therefore, awareness of PRES is of crucial importance for the intensivist.

Modulation of voltage-gated ion channels on SH-SY5Y neuroblastoma by non-ionic surfactant, Cremophor EL

Cremophor EL (CrEL) is a non-ionic surfactant widely used as a vehicle for insoluble drugs, including immunosuppressive and anticancer agents. Although CrEL has often been reported to induce sensory neuropathies, its action on voltage-gated ion channels remains unknown. We show here that CrEL modulates voltage-gated sodium current (INa) and potassium current (IK) of human neuroblastoma cells (SH-SY5Y). First, CrEL suppressed the amplitude of INa and that of IK. The suppression-concentration curve for INa was gradual but that for IK was steeper, indicating that INa remains incompletely blocked by high concentrations of CrEL, which greatly reduce IK. Thus, it is possible that CrEL paradoxically increases neuronal excitability at higher concentrations. Next, CrEL accelerated IK's inactivation process. The voltage-dependent inactivation of IK showed two time constants, τ(f) of 322±49 ms and τ(s) of 2925±184 ms, under the control condition. By applying 1000 ppm CrEL, three time constants-τ(u) of 23±2 ms, τ(f) of 196±19 ms, and τ(s) of 1396±127 ms-appeared in the inactivation process. This modified inactivation of IK probably disturbs the repolarizing phases of action potentials. These modulations of voltage-gated ion channels by CrEL may cause abnormal excitability involved in neuropathies.