Neurotoxicity of calcineurin inhibitors: impact and clinical management

Differences in the incidence and clinical evolution of early neurotoxicity after liver transplantation based on tacrolimus formulation used in the immunosuppressive induction protocol

INTRODUCTION

Posttransplant early calcineurin inhibitor (CNI)-induced neurotoxicity (ECIIN) was related to high CNI levels, among other factors. Minimizing exposure could modify its incidence or clinical evolution.

OBJECTIVE

To compare the incidence, predisposing factors, and clinical evolution of ECIIN after immunosuppressive induction with low-dose tacrolimus-MR (Advagraf) or conventional dose tacrolimus (Prograf).

PATIENTS AND METHODS

We matched 71 patients treated with an immunosuppression induction schedule with basiliximab and low doses of Advagraf (cases group) 1:1 by recipient age and indication for liver transplantation (OLT) with patients treated with a conventional tacrolimus regimen (control group). Baseline characteristics, liver and kidney function, operative technical characteristics, kidney function, and C0 tacrolimus levels at several time points after liver OLT were analyzed.

RESULTS

There were 31 cases of ECIIN (21%), 14 in the cases group (20%) and 17 in the control group (24%; P < .001). The incidence of ECIIN was higher in alcoholic liver disease (odds ratio [OR], 8.2; 95% CI, 2.3-28.6; P < .001) and past history of encephalopathy (OR, 2.6; 95% CI, 1.16-5.9; P < .02). Among cases, the incidence of ECIIN was higher when encephalopathy signs were present at time of transplantation (36% vs 12%; P < .001). Control of ECIIN required a switch to cyclosporine therapy in all those in the cases group, whereas this was only needed for 9 cases in the control group (47%; P < .001).

CONCLUSION

In this study, although the incidence rate of neurotoxicity induced by Advagraf was lower than the induced by Prograf, it did not respond to routine treatment and required a significantly higher rate of switch to cyclosporine for its control.

Immunosuppression based on everolimus in liver transplant recipients with severe early post-transplantation neurotoxicity

The immunosuppressive management of liver transplant recipients suffering early calcineurin inhibitor-induced neurotoxicity is a challenge in daily clinical practice. We have assessed the use of everolimus as the main immunosuppressant in patients presenting severe neurotoxicity in the early post-transplantation period. From October 1988 to October 2012, 10 patients in our center received everolimus because of severe neurotoxicity in the 1st 3 months after transplantation. We analyzed several variables associated with this treatment, including patient characteristics, time from liver transplantation to conversion to everolimus, immunosuppression regimens before and after conversion, treatment efficacy, adverse events, and discontinuation after conversion. Median follow-up after conversion to everolimus was 27 months (range, 1-63 mo). Neurotoxic events were: akinetic mutism in 4 patients, repeated convulsions in 3, cerebrovascular accident in 1, Guillain-Barré syndrome in 1, and disabling tremor in 1. Treatment with calcineurin inhibitors was discontinued in all patients. Post-conversion regimens consisted of everolimus plus mycophenolate mofetil (MMF) plus steroids in 7 patients, everolimus plus MMF in 1, everolimus plus steroids in 1, and everolimus alone in 1. Liver function was maintained for ≥1 month in all patients except 1, who presented a severe rejection that was treated with steroid bolus and Neoral cyclosporine. Neurologic function was fully recovered in 8 patients. In 1 patient with akinetic mutism and another with convulsions, tacrolimus was reintroduced at 2 months and 1 month, respectively, after resolution of the neurotoxic event. Everolimus is feasible and effective as the main immunosuppressant in patients suffering severe neurotoxicity during the 1st 3 months after transplantation. It allows neurologic function to be recovered while maintaining adequate liver function.

Prevention of recurrent episodes of rhabdomyolysis with tacrolimus in a transplant recipient with myopathy

Genetic muscular disorders are known risk factors for rhabdomyolysis, which may result in acute kidney injury. Recurrent episodes of acute kidney injury can lead to chronic kidney disease and eventually end-stage renal failure. We describe a patient with chronic kidney disease that developed in the setting of recurrent rhabdomyolysis, resulting in the requirement for renal transplantation. After transplantation, the maintenance of tacrolimus trough concentrations above what is typically prescribed for standard renal transplant recipients appeared to confer protection from further episodes of rhabdomyolysis. This is consistent with previous case series that demonstrated a therapeutic benefit of the calcineurin inhibitor cyclosporine in collagen VI myopathies in the nontransplant population. This case report suggests the potential application of higher tacrolimus targets in patients who have undergone renal transplantation in the setting of recurrent rhabdomyolysis leading to end-stage renal failure.

Switching STudy of Kidney TRansplant PAtients with Tremor to LCP-TacrO (STRATO): an open-label, multicenter, prospective phase 3b study

Tremor is a common side effect of tacrolimus correlated with peak-dose drug concentration. LCPT, a novel, once-daily, extended-release formulation of tacrolimus, has a reduced Cmax with comparable AUC exposure, requiring a ~30% dose reduction vs. immediate-release tacrolimus. In this phase 3b study, kidney transplant recipients (KTR) on a stable dose of tacrolimus and with a reported clinically significant tremor were offered a switch to LCPT. Tremor pre- and seven d post-conversion was evaluated by independent, blinded movement disorder neurologists using the Fahn-Tolosa-Marin (FTM) scale and by an accelerometry device; patients completed the QUEST (quality of life in essential tremor) and the Patient Global Impression of Change. There were 38 patients in the mITT population. A statistically and clinically significant improvement in tremor (FTM score, amplitude as measured by the accelerometry device and QOL [p-values < 0.05]) resulted post-conversion. Change in QUEST was significantly (p = 0.006) correlated (R = 0.44) with change in FTM; 78.9% of patients reported an improvement after switching to LCPT (p < 0.0005). To our knowledge this is the first trial in KTR that utilizes a sophisticated and reproducible measurement of tremor. Results suggest LCPT is associated with clinically meaningful improvement of hand tremor and may be an alternative management approach in lieu of further dose reduction of immediate-release tacrolimus for patients experiencing tremor.

Once-daily LCP-Tacro MeltDose tacrolimus for the prophylaxis of organ rejection in kidney and liver transplantations

Tacrolimus is a cornerstone of the immunosuppression regimen for prevention of allograft rejection in kidney and liver transplantations, with efficacy proven in many clinical trials. The currently available and extensively used tacrolimus formulations are flawed by large inter- and intra-individual variability, low bioavailability, wide peak-to-trough fluctuations and a narrow therapeutic index. Drug delivery technology can significantly impact the pharmacologic action of a drug, influencing its pharmacokinetic and subsequent therapeutic profile. LCP-Tacro is a novel, prolonged-release, MeltDose(®) formulation of tacrolimus designed for once-daily administration. A hallmark differentiation between this formulation and other once- and twice-daily tacrolimus products is the proprietary MeltDose drug delivery technology which is designed to improve the bioavailability of drugs with low water solubility. Considering the studies conducted to date, once-daily LCP-Tacro has shown improved pharmacokinetic properties, rapid achievement of therapeutic trough levels, consistent exposure, non-inferior efficacy and similar safety, with lower tacrolimus dose than other tacrolimus formulations.

Impaired motor competence in children with transplanted liver

OBJECTIVES

Although reduced cognitive function has been demonstrated after liver transplantation in children, few data are available concerning motor competence.

METHODS

Thirty-five children ages 4 to 12 years were tested using Movement Assessment Battery for Children (M-ABC) test at a median of 5.1 (3.9-6.9) years after liver transplantation and compared with reference material of healthy children.

RESULTS

Children with transplantation had worse M-ABC score 8.0 (interquartile range 5.0-11.5), compared with healthy children 3.5 (1.0-6.0) (P < 0.0001). All of the subscores (manual dexterity [P < 0.0001], ball skills [P = 0.0037], and balance [P = 0.0032]) were significantly worse in the children with liver transplantation compared with the healthy reference group. Twenty-nine percent of the children with liver transplantation had impaired motor competence, compared with 9% of a healthy reference group. Seventeen of the patients with transplantation were retested 1 year later, and 11 were tested 4 years later with no changes in total M-ABC score. Ball skill competence was worse 4 years after first assessment (P = 0.013). For children with transplantation and cholestatic liver disease (n =26), renal function was a significant predictor for total M-ABC score (P = 0.018).

CONCLUSIONS

Children with liver transplantation had impaired motor competence compared with healthy children. Ball skills developed adversely several years after liver transplantation, and motor competence did not improve with time after transplantation. Renal function was a significant predictor for motor competence in children with liver transplantation and cholestatic liver disease.

Genetic findings in obsessive-compulsive disorder connect to brain-derived neutrophic factor and mammalian target of rapamycin pathways: implications for drug development

Traditional pharmacological approaches to the treatment of obsessive-compulsive disorder (OCD) are based on affecting serotonergic and dopaminergic transmission in the central nervous system. However, genetic epidemiology findings are pointing to glutamate pathways and developmental genes as etiological in OCD. A review of recent genetic findings in OCD is conducted, and bioinformatics approaches are used to locate pathways relevant to neuroprotection. The OCD susceptibility genes DLGAP1, RYR3, PBX1-MEIS2, LMX1A and candidate genes BDNF and GRIN2B are components of the neuronal growth, differentiation and neurogenesis pathways BDNF-mTOR. These pathways are emerging as a promising area of research for the development of neuroprotective pharmaceuticals. Emergent genetic epidemiologic data on OCD and repetitive behaviors may support new approaches for pharmacological discovery. Neuroprotective approaches that take into consideration glutamate-mediated BDNF-mTOR pathways are suggested by OCD susceptibility genes.

Anorexia nervosa in a pediatric renal transplant recipient and its reversal with cyclosporine

We report a 16-yr-old female who developed AN within a month after renal transplantation and its resolution after switching from tacrolimus to cyclosporine. Her initial maintenance immunosuppressive regimen after renal transplantation consisted of tacrolimus, mycophenolate, and steroid. She had 7 kg weight loss within the first month of transplant with subsequent 10, 12, 17, and 19 kg loss after three, five, seven, and nine months of transplant, respectively. Besides weight loss and disturbances in body image, the patient developed alopecia, bradycardia, and persistent secondary amenorrhea. Upon switching to cyclosporine from tacrolimus nine months after transplant, she started regaining weight with 5 kg gain within two months and 10 kg after four months. She restarted her menstrual cycle, alopecia and bradycardia resolved, and her body image disturbance improved. Here, we describe a very unusual neuropsychiatric side effect of tacrolimus and its resolution with another calcineurin inhibitor, cyclosporine, in an adolescent renal transplant recipient.

Evaluating the Risks of High Altitude Travel in Chronic Liver Disease Patients

Luks, Andrew M., and Erik R. Swenson. Clinician's Corner: Evaluating the risks of high altitude travel in chronic liver disease patients. High Alt Med Biol 16:80-88, 2015.--With improvements in the quality of health care, people with chronic medical conditions are experiencing better quality of life and increasingly participating in a wider array of activities, including travel to high altitude. Whenever people with chronic diseases travel to this environment, it is important to consider whether the physiologic responses to hypobaric hypoxia will interact with the underlying medical condition such that the risk of acute altitude illness is increased or the medical condition itself may worsen. This review considers these questions as they pertain to patients with chronic liver disease. While the limited available evidence suggests there is no evidence of liver injury or dysfunction in normal individuals traveling as high as 5000 m, there is reason to suspect that two groups of cirrhosis patients are at increased risk for problems, hepatopulmonary syndrome patients, who are at risk for severe hypoxemia following ascent, and portopulmonary hypertension patients who may be at risk for high altitude pulmonary edema and acute right ventricular dysfunction. While liver transplant patients may tolerate high altitude exposure without difficulty, no information is available regarding the risks of long-term residence at altitude with chronic liver disease. All travelers with cirrhosis require careful pre-travel evaluation to identify conditions that might predispose to problems at altitude and develop risk mitigation strategies for these issues. Patients also require detailed counseling about recognition, prevention, and treatment of acute altitude illness and may require different medication regimens to prevent or treat altitude illness than used in healthy individuals.

The transferability from rat subacute 4-week oral toxicity study to translational research exemplified by two pharmaceutical immunosuppressants and two environmental pollutants with immunomodulating properties

Exposure to chemicals may have an influence on the immune system. Often, this is an unwanted effect but in some pharmaceuticals, it is the intended mechanism of action. Immune function tests and in depth histopathological investigations of immune organs were integrated in rodent toxicity studies performed according to an extended OECD test guideline 407 protocol. Exemplified by two immunosuppressive drugs, azathioprine and cyclosporine A, and two environmental chemicals, hexachlorobenzene and benzo[a]pyrene, results of subacute rat studies were compared to knowledge in other species particular in humans. Although immune function has a high concordance in mammalian species, regarding the transferability from rodents to humans various factors have to be taken into account. In rats, sensitivity seems to depend on factors such as strain, sex, stress levels as well as metabolism. The two immunosuppressive drugs showed a high similarity of effects in animals and humans as the immune system was the most sensitive target in both. Hexachlorobenzene gave an inconsistent pattern of effects when considering the immune system of different species. In some species pronounced inflammation was observed, whereas in primates liver toxicity seemed more obvious. Generally, the immune system was not the most sensitive target in hexachlorobenzene-treatment. Immune function tests in rats gave evidence of a reaction to systemic inflammation rather than a direct impact on immune cells. Data from humans are likewise equivocal. In the case of benzo[a]pyrene, the immune system was the most sensitive target in rats. In the in vitro plaque forming cell assay (Mishell-Dutton culture) a direct comparison of cells from different species including rat and human was possible and showed similar reactions. The doses in the rat study had, however, no realistic relation to human exposure, which occurs exclusively in mixtures and in a much lower range. In summary, a case by case approach is necessary when testing immunotoxicity. Improvements for the translation from animals to humans related to immune cells can be expected from in vitro tests which offer direct comparison with reactions of human immune cells. This may lead to a better understanding of results and variations seen in animal studies.

Managing psychosis in a renal transplant recipient with bipolar affective disorder and allograft rejection

Management of mental health issues in the post-transplant setting can be difficult given the potential for medication related neurotoxicity. The lack of established guidelines in this area further compounds this difficulty. The current report details the course of patient with stable bipolar affective disorder prior to renal transplantation, who developed de novo psychosis post-transplantation as an adverse effect of her tacrolimus therapy. The patient was unable to take her usual oral immunosuppressants due to the severity of her psychosis and she eventually required alemtuzumab parenterally as rescue therapy from rejection. This case highlights the diagnostic and therapeutic challenges when dealing with transplant recipients with significant psychosis.

Pseudotumor cerebri associated with cyclosporine use in severe atopic dermatitis

Cyclosporine use can cause neurologic complications in 0.5% to 35% of cases, although the appearance of pseudotumor cerebri (PC) is exceptional. PC secondary to the use of cyclosporine is described mainly in individuals who have received a bone marrow transplant. We report the first case, to our knowledge, of PC secondary to the use of cyclosporine in a child with severe atopic dermatitis, with satisfactory resolution and without vision sequelae.

Central nervous system complications after liver transplantation: common but mostly transient phenomena

Although central nervous system complications (CNSCs) are common after orthotopic liver transplantation (OLT), standardized prospective studies are still lacking. This prospective study was aimed at determining the incidence of CNSCs, describing their clinical presentations, and establishing predicting factors. One hundred thirty-six adult patients who underwent OLT at Hannover Medical School between December 2008 and June 2011 were included. Weekly examinations were performed by a neurologist during the hospital stay after OLT. Patient data, donor data, and operative and postoperative variables were collected. Patients with cerebral dysfunction after OLT underwent a diagnostic work-up, which included brain imaging and, if necessary, cerebrospinal fluid analysis. Patients with central nervous system (CNS) symptoms but negative imaging and cerebrospinal fluid results and patients with pontine myelinolysis or posterior reversible encephalopathy syndrome were placed in a metabolic-toxic CNSC group, and patients with strokes, intracranial hemorrhaging, or CNS infections were placed in a nonmetabolic CNSC group. Multiple regression analysis was used to identify independent risk factors for the development of metabolic-toxic CNSCs. After excluding two patients that died after OLT without regaining consciousness, forty-four (32.8%) patients developed CNSCs: 37 of these patients (27.6%) had metabolic-toxic CNSCs, and 7 (5.2%) had nonmetabolic CNSCs. Acute-on-chronic liver failure, the number of subsequent surgeries, and primary sclerosing cholangitis were identified as independent predictors for the development of metabolic-toxic CNSCs. Metabolic-toxic CNSCs were associated with prolonged hospital stays, and nonmetabolic CNSCs were associated with higher mortality. In conclusion, CNSCs are common and relevant complications after OLT. Patients after OLT, especially with risk factors, should undergo a regular standardized neurological examination that would allow early detection of these complications.

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'.

Predictive factors of neurological complications and one-month mortality after liver transplantation

Background: Neurological complications are common after orthotopic liver transplantation (OLT). We aimed to characterize the risk factors associated with neurological complications and mortality among patients who underwent OLT in the post-model for end-stage liver disease (MELD) era.

Methods: In a retrospective review, we evaluated 227 consecutive patients at the Keck Hospital of the University of Southern California before and after OLT to define the type and frequency of and risk factors for neurological complications and mortality.

Results: Neurological complications were common (n = 98), with encephalopathy being most frequent (56.8%), followed by tremor (26.5%), hallucinations (11.2%), and seizure (8.2%). Factors associated with neurological complications after OLT included preoperative dialysis, hepatorenal syndrome, renal insufficiency, intra-operative dialysis, preoperative encephalopathy, preoperative mechanical ventilation, and infection. Preoperative infection was an independent predictor of neurological complications (OR 2.83, 1.47–5.44). One-month mortality was 8.8% and was independently associated with urgent re-transplant, preoperative intubation, and intra-operative arrhythmia.

Conclusion: Neurological complications are common in patients undergoing OLT in the post-MELD era, with encephalopathy being most frequent. An improved understanding of the risk factors related to both neurological complications and one-month mortality post-transplantation can better guide perioperative care and help improve outcomes among OLT patients.

Drug-induced cerebellar ataxia: a systematic review

BACKGROUND AND OBJECTIVES

Cerebellar ataxia can be induced by a large number of drugs. We here conducted a systemic review of the drugs that can lead to cerebellar ataxia as an adverse drug reaction (ADR).

METHODS

We performed a systematic literature search in Pubmed (1966 to January 2014) and EMBASE (1988 to January 2014) to identify all of the drugs that can have ataxia as an ADR and to assess the frequency of drug-induced ataxia for individual drugs. Furthermore, we collected reports of drug-induced ataxia over the past 20 years in the Netherlands by querying a national register of ADRs.

RESULTS

Drug-induced ataxia was reported in association with 93 individual drugs (57 from the literature, 36 from the Dutch registry). The most common groups were antiepileptic drugs, benzodiazepines, and antineoplastics. For some, the number needed to harm was below 10. Ataxia was commonly reversible, but persistent symptoms were described with lithium and certain antineoplastics.

CONCLUSIONS

It is important to be aware of the possibility that ataxia might be drug-induced, and for some drugs the relative frequency of this particular ADR is high. In most patients, symptoms occur within days or weeks after the introduction of a new drug or an increase in dose. In general, ataxia tends to disappear after discontinuation of the drug, but chronic ataxia has been described for some drugs.

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.

Refractory intracranial hypertension in posterior reversible encephalopathy syndrome

INTRODUCTION

Posterior reversible encephalopathy syndrome (PRES) is a largely reversible disease with long-term favorable outcome. A minority of patients, however, may develop progressive cerebral edema and ischemia resulting in severe disability or death. We report a case of severe intracranial hypertension associated with PRES that was successfully treated according to intracranial pressure (ICP)- and cerebral perfusion pressure (CPP)-driven therapy.

METHODS

Case report.

RESULTS

A 42-year-old woman underwent bilateral lung transplantation for severe bronchiectasis. Her immunosuppressive regimen consisted of azathioprine, prednisone, and tacrolimus. She acutely developed an aggressive form of PRES that rapidly resulted in severe refractory intracranial hypertension despite discontinuation of potentially causative medications and adequate supportive therapy. Accordingly, second-tier therapies, including barbiturate infusion, were instituted and immunosuppression was switched to anti-thymocyte globulin followed by mycophenolate mofetil. Within 10 h of barbiturate administration, ICP dropped to 20 mmHg. Thiopental was administered for two days and then rapidly tapered because of severe urosepsis. Six months after discharge from the intensive care unit the patient returned to near-normal life, her only complaint being short-term amnesia.

CONCLUSIONS

The decision to undertake ICP monitoring in medical conditions in which no clear recommendations exist greatly relies on physicians' judgment. This case suggests that ICP monitoring may be considered in the setting of acute PRES among selected patients, when severe intracranial hypertension is suspected, provided that a multidisciplinary team of neurocritical care specialists is readily available.

Acute demyelinating polyneuropathy after lung transplantation: guillain-barré syndrome or tacrolimus toxicity?

Guillain-Barré syndrome (GBS) has been described after solid organ and bone marrow transplantation mostly due to viral infections and possibly calcineurin inhibitors. Incidence after bone marrow transplant is 0.3–0.7%, though incidence in other transplants is not well known. We present the first description of tacrolimus associated GBS in lung transplant recipients in the English language literature. The pathophysiology of tacrolimus-induced polyneuropathy is not known, but some have hypothesized that tacrolimus induces an inflammatory phenomenon by differential effects on T cell subsets. Diagnosis of association may be challenging and requires high index of suspicion. The optimal treatment of GBS-associated with tacrolimus after lung transplantation is unknown, although drug discontinuation may result in improvement in some patients, while some reports suggest that the use of IVIG and/or plasmapheresis may be helpful and safe in organ transplant recipients with severe symptoms.

Rapid Resolution of Tacrolimus Intoxication–Induced AKI With a Corticosteroid and Phenytoin

Objective: To report a novel approach to the management of tacrolimus intoxication that leads to rapid normalization of serum tacrolimus concentrations. Case Summary: A 9-year-old female renal transplant recipient developed a severe tacrolimus intoxication as a result of prolonged diarrhea, which resulted in acute kidney injury, severe dehydration, and neurological symptoms. We used a combination of intravenous steroids and intravenous phenytoin to normalize the tacrolimus level from 32 to 5 ng/mL in less than 24 hours, with complete resolution of symptoms and signs. Discussion: Tacrolimus intoxication is a rare event but may result in life-threatening complications. Treatment recommendations beyond holding the drug and enzyme induction with phenytoin or phenobarbital are elusive. This approach leads to a relatively slow normalization of the tacrolimus level over 72 hours. The authors hypothesized that additional induction of the p-glycoprotein through steroids was synergistic. Conclusions: The combination of phenytoin and a corticosteroid may be an effective approach that leads to rapid normalization of severely elevated tacrolimus levels.

Heterogeneity of radiological spectrum in tacrolimus-associated encephalopathy after lung transplantation

Background. Tacrolimus-associated encephalopathy (TAC-E) is usually described under the term of posterior reversible encephalopathy syndrome (PRES). However, a large amount of data has suggested that TAC-E is not a homogenous entity: indeed, TAC-E which is often presented with atypical and potentially misleading imaging characteristics does not always correspond to PRES. Objective. We aimed to identify the spectrum of brain MR imaging of TAC-E and discuss the underlying pathophysiological features. Methods. From September 2008 to October 2010, the neurological statuses of 45 patients, who underwent lung transplantation with TAC as posttransplantation immunosuppressive therapy, were regularly assessed in a prospective study. MRI was repeatedly performed, until recovery, in patients who developed central neurological symptoms. Results. Symptoms suggestive of encephalopathy occurred in five out of 45 patients (11.1%). According to our MRI study, two patients presented with reversible bilateral and relatively symmetric subcortical white matter edema with proximal vasospasms on MRA; however, three other patients were characterized by coexistence of two different lesions including laminar cortical infarcts with hemorrhagic transformation not typically found in PRES and reversible deep white matter edema, associated with distal vasospasms on MRA. Conclusions. It is considered that the mechanism of TAC-E would be more heterogenous than commonly perceived.

N-Octanoyl dopamine transiently inhibits T cell proliferation via G1 cell-cycle arrest and inhibition of redox-dependent transcription factors

Recently, we developed a nonhemodynamic dopamine derivative, NOD, which has profound anti-inflammatory effects in vitro. As NOD also protects rats from ischemic AKI, the present study tested whether NOD is able to modulate cellular immunity for potential use as a T cell-suppressive agent. To this end, T cells were stimulated by anti-CD3/CD28 or PMA/ionomycin in the presence or absence of different concentrations of NOD. T cell proliferation, activation markers, intracellular cytokine expression, and activation of transcription factors were assessed. Whereas T cell proliferation was inhibited significantly by NOD at Day 3, proliferation was restored at Day 7 or later depending on the NOD concentration used. Inhibition of proliferation was reflected by a diminished CD25 expression and switch from naive to memory T cells. Early TCR activation events were unaffected, yet NF-κB and AP-1 were strongly inhibited by NOD. The inhibitory effect of NOD seemed to be dependent on its redox activity, as NOT, a redox-inactive NOD derivate, did not influence proliferation. NOD displayed synergistic effects with CNIs on T cell proliferation. Our data demonstrate that NOD displays T cell-suppressive activity. In keeping with its anti-inflammatory action and its beneficial effect on ischemia-induced AKI, NOD may be an interesting drug candidate to prevent CNI-related side-effects.

Beyond calcineurin inhibitors: emerging agents in kidney transplantation

PURPOSE OF REVIEW

Despite their effectiveness, calcineurin inhibitors (CNIs) represent a major obstacle in the improvement of long-term graft survival in transplantation. The identification of new agents to implement CNI-free regimens is the focus of current transplant research. The purpose of this review is to summarize the novel immunosuppressive agents, including details about their mechanisms of action, stages of development, potential benefits and challenges.

RECENT FINDINGS

Targeting costimulation with belatacept is now an option for controlling the alloimmune response and has proved to be more effective in preserving long-term allograft function than CNIs despite an increased rate of acute rejection in some studies. mTOR inhibitors are also promising with their remarkable antineoplastic properties, though frequent side-effects may limit their broader use. Other agents under development include JAK inhibitors, CD40 blockade and leukocyte adhesion blockers, with unique potential benefits and side-effects in transplantation.

SUMMARY

Novel immunosuppressive agents are now available for use in CNI-free regimens in solid organ transplantation. Timing of initiation as well as long-term efficacy and safety are questions that remain to be answered in future clinical trials.

Life-long diseases need life-long treatment: long-term safety of ciclosporin in canine atopic dermatitis

Ciclosporin (Atopica; Novartis Animal Health) has been licensed for canine atopic dermatitis (AD) since 2002. Adverse events (AEs) have been reported in 55 per cent of 759 dogs in 15 clinical trials, but are rare in pharmacovigilance data (71.81 AEs/million capsules sold). Gastrointestinal reactions were most common, but were mild and rarely required intervention. Other AEs were rare (≤1 per cent in clinical trials; <10/million capsules sold). Hirsutism, gingival hyperplasia and hyperplastic dermatitis were rarely significant and resolved on dose reduction. Ciclosporin decreases staphylococcal and Malassezia infections in AD, and at the recommended dose is not a risk factor for other infections, neoplasia, renal failure or hypertension. The impact on glucose and calcium metabolism is not clinically significant for normal dogs. Concomitant treatment with most drugs is safe. Effects on cytochrome P450 and MDR1 P-glycoprotein activity may elevate plasma ciclosporin concentrations, but short-term changes are not clinically significant. Monitoring of complete blood counts, urinalysis or ciclosporin levels is not justified except with higher than recommended doses and/or long-term concurrent immunosuppressive drugs. Ciclosporin is not a contraindication for killed (including rabies) vaccines, but the licensed recommendation is that live vaccination is avoided during treatment. In conclusion, ciclosporin has a positive risk-benefit profile for the long-term management of canine AD.

Risk factors for neurological complications and their correlation with survival following pediatric liver transplantation

Despite the improved outcomes of LT, post-operative NCs remain a significant cause of morbidity and mortality. The aim of the study was to identify the incidence of and risk factors for NCs in children who underwent LT. The medical records of pediatric patients who underwent LT at Asan Medical Center Children's Hospital between January 1994 and December 2010 were retrospectively analyzed. The onset and types of NC and pretransplant variables associated with NC were evaluated. We identified 190 children (85 boys [44.7%], 105 girls [55.3%]) of mean age 4.1 ± 4.7 yr, who underwent LT. Forty-six NCs occurred in 41 (21.6%) patients after LT, the most common being seizures (n = 13, 28.3%) and encephalopathy (n = 10, 21.7%). Of the 46 NCs, 24 (52.2%) occurred within three months after LT. Multivariate analysis showed that primary liver disease, preoperative neurological problems, preoperatively higher serum creatinine concentration, and graft failure were significant risk factors for NCs. The survival rate was significantly lower for patients with NCs than for those without (p < 0.001). NCs after pediatric LTs were common and associated with a higher mortality rate in our study. Close monitoring and appropriate risk management may improve the long-term outcomes of pediatric patients who undergo LT.

Tacrolimus-related seizure after pediatric liver transplantation--a single-center experience

To identify the risk factors for new-onset seizures after pediatric LT and to assess their clinical implications and long-term prognosis. The clinical and laboratory data of 27 consecutive children who underwent LT from January 2007 to December 2010 in our center were analyzed retrospectively. Patients were divided into seizures group and a non-seizures group. Pre-operative, intra-operative, and post-operative data were collected. Seizures occurred in four children, an incidence of 14.8%. All exhibited generalized tonic-clonic seizures within the first two wk after LT. Univariate analysis showed that the risk factors associated with seizures after pediatric LT included gender, pediatric end-stage liver disease score before surgery, Child-Pugh score before surgery, serum total bilirubin after surgery, and trough TAC level. Multivariate analysis showed that trough TAC level was the only independent risk factor associated with the seizures. All children who experienced seizures survived with good graft function and remained seizure-free without anti-epileptic drugs over a mean follow-up period of 33.7 ± 14.6 months. High trough TAC level was the predominant factor that contributed to seizures in the early post-operative period after pediatric LT. High PELD and Child-Pugh scores before LT and high post-operative serum Tbil may be contributory risk factors for TAC-related seizures.

Central nervous system infections in cancer patients and hematopoietic stem cell transplant recipients

Central nervous system (CNS) infections in cancer patients present a diagnostic and therapeutic challenge for clinicians. While CNS infections are not frequent complications of cancer, its therapies, or hematopoietic stem cell transplantation, the importance of CNS infections lies in their propensity to result in profound morbidity and substantial mortality in this vulnerable patient population. With an expanding population of patients with malignant disease undergoing more potent and aggressive therapies and with the advent of newer immunomodulatory agents, the incidence of CNS infectious complications is likely to rise. This chapter will summarize the clinical and diagnostic evaluation of potential infections of the CNS in these patients and will discuss particular pathogens of interest with regard to this at-risk patient population.

Neurotoxicity of commonly used hepatic drugs

Neurologic complications are common side-effects of immunosuppressive medications used in the prevention of graft rejection after organ transplantation. The medications most commonly encountered include the calcineurin inhibitors and mycophenolate mofetil. Depression is the most commonly encountered neurotoxicity; however, severe but rare adverse neurological effects related to these therapies have been reported. Interferons, ribavirin, and protease inhibitors are therapeutic options commonly encountered in the treatment of hepatitis. Nucleoside analogs such as adefovir dipivoxil and entecavir carry significant risks for the development of lactic acidosis and hepatic dysfunction; however, most common adverse effects to these therapies in general are mild. While the mechanisms of action are poorly elucidated, they are discussed along with treatment strategies.

Neurologic aspects of heart transplantation

Cardiac transplantation remains the best treatment option for patients with end-stage, NYHA class IV heart failure who have failed conventional therapy. However, transplant rates have remained static largely due to limited organ donor supplies. Therefore, appropriate allocation of this precious resource is critical to maximize benefit, both at a patient level and at a societal level. Neurologic diseases, such as cerebrovascular disease and peripheral neuropathy, are prevalent in this patient population, as the major risk factors for heart disease place patients at risk for neurologic disease as well. Examples include hypertension, smoking, hypercholesterolemia, obesity, and diabetes. Pretransplant neurologic evaluation is very important to identify conditions that may limit survival after cardiac transplantation. In general, systemic diseases exacerbated by immunosuppression, conditions limiting ability to rehabilitate, and dementias are considered contraindications. Post-transplant neurologic complications are divided into central versus peripheral, and early versus late. The most common early complication is ischemic stroke. Other serious complications include hemorrhagic stroke, encephalopathy, and critical illness neuropathy. Over the long term, post-transplant immunosuppressive regimens are considered "a double edged sword." Although immunosuppressive medications are critical to preventing rejection and allograft dysfunction, they do have significant risk of morbidity and mortality associated with them, including neurologic side-effects. These include: (1) drug toxicities, such as lowering of seizure thresholds; (2) encephalopathy, such as posterior reversible encephalopathy syndrome (PRES); (3) infections; (4) malignancies, such as post-transplant lymphoproliferative disorder (PTLD). Many of the same considerations discussed in adult heart transplant recipients apply to pediatric heart transplant recipients as well. In children, seizures are the most common neurologic complication, although other neurologic complication rates are comparable.

Neurologic complications in renal transplantation

Neurologic complications following kidney transplant are more common than in the general population with the reported incidence around 10-21%. Need for multiple drugs, decreased cellular immunity, accelerated atherosclerotic disease, and frequency of metabolic abnormalities are the most common predisposing factors for neurologic abnormalities. Neurologic side-effects of calcineurin inhibitors range from mild tremors to paraplegia or posterior reversible encephalopathy syndrome (PRES) and are generally reversible by lowering the dose or complete discontinuation of the drug when possible. Clinical presentation of central nervous system infection in transplant recipients can be different from the normal population as the anti-inflammatory effects of immunosuppressive therapy may obscure signs of meningeal inflammation and changes in the level of consciousness may be subtle. Bacterial infections remain the most common infections but unusual pathogens figure prominently in the differential diagnosis. The most frequent malignancies of the brain are lymphomas and metastatic tumors which are for the most part, de novo malignancies from immunosuppression. Decreasing immunosuppression is almost always a part of treating malignancy. The prevalence of stroke is reported to be around 8% with age>40 years, diabetic nephropathy as the underlying cause of end-stage kidney disease, and peripheral vascular disease being the strongest predictors.

Immunosuppressive therapy in immune-mediated liver disease in the non-transplanted patient

Autoimmune liver disease management goals are primarily slowing disease progression and symptomatic treatment. There are few options for curative medical management other than transplant for a spectrum of autoimmune liver disease that encompasses autoimmune hepatitis, primary biliary cirrhosis, primary sclerosing cholangitis as well as their overlap syndromes. These diseases are managed primarily with immunosuppressive therapy. Herein, we review the current literature, detailing the promise and pitfalls of the recommended immunosuppressive therapy for these challenging diseases.

Posterior reversible encephalopathy syndrome in pediatric patients undergoing treatment for hemophagocytic lymphohistiocytosis: clinical outcomes and putative risk factors

Background

Hemophagocytic lymphohistiocytosis (HLH) is a rare multiorgan disease of toxic immune activation caused by the interaction of cytotoxic T cells and innate immune cells and frequently involves the central nervous system (CNS). Posterior reversible encephalopathy syndrome (PRES) might develop during treatment with the HLH-2004 protocol from the Histiocyte Society. The aims of this study were to evaluate clinical outcomes and putative risk factors for prediction of PRES related to HLH.

Methods

We reviewed the medical records of 28 patients with HLH who were treated between April 2005 and April 2012. We compared various clinical and laboratory parameters in patients without or with PRES to evaluate putative risk factors related to development of PRES.

Results

Six (21.4%) of the patients experienced PRES during treatment with the HLH-2004 protocol. Clinical and laboratory manifestations were not different compared with other conditions causing PRES. The main mechanism of PRES may be related to the HLH-2004 protocol and a high pro-inflammatory state. Most patients recovered quickly from neurologic manifestations without significant long-term sequelae. Preceding hypertension, an increase in ferritin level >50% compared with 1 week before development of PRES and hyponatremia were statistically significant factors.

Conclusion

PRES is clinically reversible and has a favorable outcome in patients with HLH. Awareness of PRES and a differential diagnosis of other causes of neurologic complications, including CNS involvement of HLH, can help avoid unnecessary treatment or delayed management. Patients with preceding hypertension, hyponatremia, and rising ferritin levels during HLH treatment should be closely monitored for PRES.

Analysis of seizure risk factors after allogeneic hematopoietic stem cell transplantation: a 8 case report and literature review

The clinical characteristics of patients with seizures after allogeneic hematopoietic stem cell transplantation (allo-HSCT) were analyzed. A total of 8 cases of seizures after allo-HSCT were investigated. Clinical data of these cases were studied retrospectively. Of 159 cases subjected to allo-HSCT, seizure occurred in 8 cases during 29-760 days after transplantation, median survival time was 46 days, and there were 6 cases of tonic-clonic seizure. The incidence of seizure after matched unrelated HSCT was higher than that after related HSCT (P=0.017). Of 7 cases treated with cyclosporine A (CsA), 4 cases obtained high blood levels of CsA. In addition, hyponatremia was diagnosed in 5 cases. Abnormal electroencephalogram and brain MRI findings were found in some cases. During 20 days after seizure, 2 cases died due to infection and graft-versus-host disease (GVHD), respectively. It was suggested that multiple factors are associated with seizures after allo-HSCT. Rapid identification and correction of the causative factors are very important to prevent permanent central nervous system damage and reduce the mortality.

Systemic use of non-biologic agents in orofacial diseases: other immunomodulatory agents

Systemic non-biologic agents have long been in clinical use in medicine--often with considerable efficacy, albeit with some adverse effects--as with all medications. With the advent of biologic agents, all of which currently are restricted to systemic use, there is a growing need to ensure which agents have the better therapeutic ratio. The non-biologic agents (NBAs) include a range of agents, most importantly the corticosteroids (steroids). Previous articles by us in this series have discussed systemic use of corticosteroids and purine synthesis inhibitors; the other immunomodulating agents (calcineurin inhibitors, thalidomide, dapsone, colchicine and cyclophosphamide) are reviewed in this final article.

Association between calcineurin inhibitor treatment and peripheral nerve dysfunction in renal transplant recipients

Neurotoxicity is a significant clinical side effect of immunosuppressive treatment used in prophylaxis for rejection in solid organ transplants. This study aimed to provide insights into the mechanisms underlying neurotoxicity in patients receiving immunosuppressive treatment following renal transplantation. Clinical and neurophysiological assessments were undertaken in 38 patients receiving immunosuppression following renal transplantation, 19 receiving calcineurin inhibitor (CNI) therapy and 19 receiving a calcineurin-free (CNI-free) regimen. Groups were matched for age, gender, time since transplant and renal function and compared to normal controls (n = 20). The CNI group demonstrated marked differences in nerve excitability parameters, suggestive of nerve membrane depolarization (p < 0.05). Importantly, there were no differences between the two CNIs (cyclosporine A or tacrolimus). In contrast, CNI-free patients showed no differences to normal controls. The CNI-treated patients had a higher prevalence of clinical neuropathy and higher neuropathy severity scores. Longitudinal studies were undertaken in a cohort of subjects within 12 months of transplantation (n = 10). These studies demonstrated persistence of abnormalities in patients maintained on CNI-treatment and improvement noted in those who were switched to a CNI-free regimen. The results of this study have significant implications for selection, or continuation, of immunosuppressive therapy in renal transplant recipients, especially those with pre-existing neurological disability.