Tacrolimus-Associated Posterior Reversible Encephalopathy Syndrome after Solid Organ Transplantation

Tacrolimus-associated neurotoxicity isolated to the brainstem: two illustrative cases and a systematic review of the literature

INTRODUCTION

Tacrolimus-associated neurotoxicity (TAN) manifests with wide clinical spectrum, ranging from mild tremors to severe encephalopathy. The isolated involvement of the brainstem is a rarely documented presentation of TAN, and its clinical and diagnostic characteristics are unclear.

METHODS

We report two cases of brainstem-isolated TAN (bi-TAN). Moreover, we performed a systematic review of the literature on bi-TAN and extracted data concerning demographics, clinical characteristics, radiological features, and management. The systematic literature search followed PRISMA guidelines and a pre-defined protocol.

RESULTS

Eleven patients, including our two, were identified (mean age: 41.3 years, ± 18.8; five males, 45%). Speech disturbance was the most common clinical presentation (45%). The mean latency from Tacrolimus initiation to bi-TAN onset was 26 days (± 30.8). Tacrolimus serum level tested above the reference range in three patients (mean: 26.83 ± 5.48). Brain MRI showed T2-FLAIR hyperintensities; three showed restricted diffusion on ADC maps. Neurological symptoms resolved completely in seven patients (63%) after Tacrolimus withdrawal or dose reduction.

CONCLUSIONS

Our findings suggest that bi-TAN could represent a brainstem variant of posterior reversible encephalopathy syndrome. Recognition of bi-TAN as a potential cause of isolated brainstem lesions is crucial to disentangle the diagnostic work-up and ensure prompt withdrawal or reduction of the offending agent.

Tacrolimus-induced posterior reversible encephalopathy syndrome following liver transplantation

In this editorial, we talk about a compelling case focusing on posterior reversible encephalopathy syndrome (PRES) as a complication in patients undergoing liver transplantation and treated with Tacrolimus. Tacrolimus (FK 506), derived from Streptomyces tsukubaensis, is a potent immunosuppressive macrolide. It inhibits T-cell transcription by binding to FK-binding protein, and is able to amplify glucocorticoid and progesterone effects. Tacrolimus effectively prevents allograft rejection in transplant patients but has adverse effects such as Tacrolimus-related PRES. PRES presents with various neurological symptoms alongside elevated blood pressure, and is primarily characterized by vasogenic edema on neuroimaging. While computed tomography detects initial lesions, magnetic resonance imaging, especially the Fluid-Attenuated Inversion Recovery sequence, is superior for diagnosing cortical and subcortical edema. Our discussion centers on the incidence of PRES in solid organ transplant recipients, which ranges between 0.5 to 5 +ACU-, with varying presentations, from seizures to visual disturbances. The case of a 66-year-old male status post liver transplantation highlights the diagnostic and management challenges associated with Tacrolimus-related PRES. Radiographically evident in the parietal and occipital lobes, PRES underlines the need for heightened vigilance among healthcare providers. This editorial emphasizes the importance of early recognition, accurate diagnosis, and effective management of PRES to optimize outcomes in liver transplant patients. The case further explores the balance between the efficacy of immunosuppression with Tacrolimus and its potential neurological risks, underlining the necessity for careful monitoring and intervention strategies in this patient population.

Posterior Reversible Encephalopathy Syndrome With Hemorrhagic Transformation in the Postoperative Period of a Kidney Transplant

Patients with end-stage renal disease (ESRD) who undergo kidney transplantation are at an increased risk of developing surgical and/or medical complications. Posterior reversible encephalopathy syndrome (PRES) is a rare complication that occurs in 0.34% of kidney transplant patients. It is characterized by a combination of neurological manifestations, risk factors, and characteristic radiological findings in neuroimaging studies. The development of PRES has been associated with various medical conditions and factors, including hypertension, the use of cytotoxic and immunosuppressive drugs, acute or chronic kidney disease, pre-eclampsia/eclampsia, autoimmune diseases, and solid organ and bone marrow transplantation. This report presents the case of a 19-year-old woman diagnosed with ESRD on hemodialysis due to lupus nephritis who experienced an episode of PRES with intraparenchymal hemorrhage during the postoperative period of kidney transplantation. The case emphasizes the importance of closely monitoring these patients during this period to enable early diagnosis and timely treatment of complications, ensuring a favorable prognosis.

Heart Transplantation-Postoperative Considerations

Heart transplantation (HT) remains the best treatment of patients with severe heart failure who are deemed to be transplant candidates. The authors discuss postoperative management of the HT recipient by system, emphasizing areas where care might differ from other cardiac surgery patients. Working together, critical care physicians, heart transplant surgeons and cardiologists, advanced practice providers, pharmacists, transplant coordinators, nursing staff, physical therapists, occupational therapists, rehabilitation specialists, nutritionists, health psychologists, social workers, and the patient and their loved ones partner to increase the likelihood of a successful outcome.

Posterior reversible encephalopathy syndrome and autoimmunity

Posterior reversible encephalopathy syndrome (PRES) is a clinical syndrome characterized by acute or subacute onset of neurological symptoms (e.g., headache, seizure, confusion, vomiting, and diminished eyesight) and impaired endothelial barrier function of the cerebral circulation that leads to bilateral subcortical vasogenic edema, while exhibiting a "reversible" feature in most cases. Clinically, various predisposing or precipitating conditions have been identified, such as hypertension, autoimmune diseases, renal dysfunction/failure, preeclampsia/eclampsia, post-transplantation conditions, and certain therapeutic agents. Among several putative mechanisms, the immune activation hypothesis prevails, as up to 50% of patients with PRES harbor abnormalities related to autoimmunity, such as concurrent systemic lupus erythematosus. In this Review, we summarize the clinical and laboratory evidence that places PRES in the context of autoimmunity.

Posterior reversible encephalopathy syndrome after lung transplantation: Risk factors and management

INTRODUCTION

Posterior reversible encephalopathy syndrome is a rare neurologic complication that can occur under immunosuppressive therapy with CNI after organ transplantation.

METHODS

We retrospectively reviewed medical records of 545 patients who underwent lung transplantation between 2012 and 2019. Within this group, we identified 30 patients with neurological symptoms typical of PRES and compared the characteristics of patients who were diagnosed with PRES (n = 11) to those who were not (n = 19).

RESULTS

The incidence of PRES after lung transplantation was 2%. Notably, 73% of the patients with PRES were female and the mean age was 39.2. Seizure (82% vs. 21%, p = .002) was the most common neurological presentation. The risk of developing PRES was significantly associated with age (OR = .92, p < .0001) and having cystic fibrosis (CF) (OP = 10.1, p < .0001). Creatinine level (1.9 vs. 1.1 mg/dl, p = .047) and tacrolimus trough level (19.4 vs. 16.5 ng/ml, p = .048) within 1 week prior to neurological symptoms were significantly higher in patients with PRES.

CONCLUSION

Renal insufficiency and high tacrolimus levels are associated with PRES. A change of immunosuppressive drug should be done after confirmed PRES diagnosis or immediately in case of severe neurological dysfunction to improve neurological outcomes and minimize the risk of early allograft rejection.

Late presentation of posterior reversible encephalopathy syndrome following liver transplantation in the setting of tacrolimus and cannabis use

A 45-year-old female presented to hospital with confusion and visual disturbances. She had undergone a liver transplant 3 years prior for cirrhosis secondary to primary biliary cholangitis. Computed tomography and magnetic resonance imaging of the brain showed features consistent with posterior reversible encephalopathy syndrome. Her medications included tacrolimus, sirolimus, and prednisone. She reported smoking 4 grams of cannabis per day. Following cessation of tacrolimus, the patient's encephalopathy and visual disturbances resolved. To our knowledge, this case represents the longest time elapsed from liver transplantation to the development of tacrolimus-associated posterior reversible encephalopathy syndrome in the literature. This case highlights the potential danger of cannabis use in transplant recipients who are on immunosuppressants such as tacrolimus. Clinicians should have a high index of suspicion for posterior reversible encephalopathy syndrome in post-transplant patients presenting with altered mental status, even years after liver transplantation, and be familiar with potential interactions between cannabis and immunosuppressants.

Posterior Reversible Encephalopathy Syndrome: A Narrative Review for Emergency Clinicians

BACKGROUND

Posterior reversible encephalopathy syndrome (PRES) is a clinicoradiologic disorder characterized by seizures, headache, altered mental status, and visual disturbances, and is often associated with acute hypertension.

OBJECTIVE

This narrative review provides a focused description of the presentation, diagnostic evaluation, and management of PRES.

DISCUSSION

PRES is associated with a variety of factors, including acute rise in blood pressure, renal disease, preeclampsia/eclampsia, and immunosuppressive therapy. The pathophysiology is theorized to involve dysfunction of cerebral autoregulation leading to vascular leak or endothelial dysfunction resulting in vasogenic edema. In the emergency department (ED), clinical findings suggestive of PRES should prompt diagnostic testing focused on confirming the diagnosis and excluding other conditions that may present similarly. Laboratory studies are primarily useful for excluding alternative diagnoses. Computed tomography (CT) and, in particular, magnetic resonance imaging (MRI) are the recommended neuroimaging modalities for diagnosis. CT and MRI may demonstrate cerebral vasogenic edema, most often in the distribution of the posterior circulation. Treatment involves management of seizures, control of blood pressure if elevated, and treatment of any underlying trigger.

CONCLUSION

PRES is a neurological disorder that is typically reversible if recognized on presentation and promptly and appropriately managed. This narrative review characterizes this condition for emergency clinicians.

When Paranoia Comes with the Treatment: Psychosis Associated with Tacrolimus Use

Tacrolimus is an immunosuppressive drug frequently used in solid organ transplant recipients. This drug has well-documented neuropsychiatric side effects in the literature, although emergence of psychotic symptoms is rare, being only described in a very few case reports. We present a case of a renal transplant recipient with no prior psychiatric history, who developed a severe psychosis secondary to supratherapeutic tacrolimus' blood concentrations. This case highlights the importance of clinical awareness to rare but severe neuropsychiatric effects due to tacrolimus use.

Posterior Reversible Encephalopathy Syndrome and Reversible Cerebral Vasoconstriction Syndrome as Syndromes of Cerebrovascular Dysregulation

PURPOSE OF REVIEW

This article describes the causes, clinical and imaging features, management, and prognosis of posterior reversible encephalopathy syndrome (PRES) and reversible cerebral vasoconstriction syndrome (RCVS), in which the underlying pathophysiology is related to reversible dysregulation of the cerebral vasculature.

RECENT FINDINGS

PRES and RCVS are descriptive terms, each bringing together conditions with similar clinical-imaging manifestations. Headache, visual symptoms, seizures, and confusion occur in both syndromes. RCVS is usually heralded by recurrent thunderclap headaches, whereas encephalopathy and seizures are typical in PRES. In PRES, brain imaging shows reversible vasogenic edema that is typically symmetric and located in subcortical regions (mostly posterior predominant). In RCVS, brain imaging is often normal; cerebral angiography shows segmental vasoconstriction-vasodilatation affecting the circle of Willis arteries and their branches. Aside from shared clinical features, significant imaging overlap exists. Both PRES and RCVS can be complicated by ischemic and hemorrhagic brain lesions; angiographic abnormalities frequently occur in PRES and vasogenic edematous lesions in RCVS. Common triggers (eg, eclampsia, vasoconstrictive and chemotherapeutic agents) have been identified. Abnormal cerebrovascular tone and endothelial dysfunction may explain both syndromes. Management of these syndromes includes the removal of identified triggers, symptomatic treatment of headache or seizures, and moderate blood pressure control. Both syndromes are self-limited, with clinical recovery occurring within days to weeks. Long-term deficits and mortality are uncommon.

SUMMARY

PRES and RCVS have been well characterized and acknowledged to have significant overlap. Advances in our understanding of pathophysiology and risk factors for poor outcome are expected to optimize the management of these not uncommon syndromes.

Aberrant TDP-43 phosphorylation: a key wind gap from TDP-43 to TDP-43 proteinopathy

TDP-43 proteinopathy is a kind of neurodegenerative diseases related to the TAR DNA-binding protein of 43-kDa molecular weight (TDP-43). The typical neurodegenerative diseases include amyotrophic lateral sclerosis (ALS), frontotemporal lobar degeneration (FTLD), Alzheimer's disease (AD), Parkinson's disease (PD) and so on. As the disease process cannot be blocked or slowed down, these patients have poor quality of life and poor prognosis, and bring a huge burden to the family and society. So far, the specific pathogenesis of TDP-43 proteinopathy is not clear, and there is no effective preventive measure and treatment program for this kind of disease. TDP-43 plays an important role in triggering or promoting the occurrence and progression of TDP-43 proteinopathy. The hyperphosphorylation of TDP-43 is undoubtedly an important factor in triggering or promoting the process of TDP-43 proteinopathy. Hyperphosphorylation of TDP-43 can inhibit the degradation of TDP-43, aggravate the aggregation of TDP-43 protein, increase the wrong localization of TDP-43 in cells, and enhance the cytotoxicity of TDP-43. More and more evidences show that the hyperphosphorylation of TDP-43 plays an important role in the pathogenesis of TDP-43 proteinopathy. Inhibition of TDP-43 hyperphosphorylation may be one of the important strategies for the treatment of TDP-43 proteinopathy. Therefore, this article reviews the role of TDP-43 phosphorylation in TDP-43 proteinopathy and the related mechanisms.

Immunosuppression-related neurological disorders in kidney transplantation

A large number of neurological disorders can affect renal transplant recipients, potentially leading to disabling or life-threatening complications. Prevention, early diagnosis and appropriate management of these conditions are critical to avoid irreversible lesions. A pivotal role in the pathogenesis of common post-transplant neurological disorders is played by immunosuppressive therapy. The most frequently administered regimen consists of triple immunosuppression, which comprises a calcineurin inhibitor (CNI), a purine synthesis inhibitor and glucocorticoids. Some of these immunosuppressive drugs may lead to neurological signs and symptoms through direct neurotoxic effects, and all of them may be responsible for the development of tumors or opportunistic infections. In this review, after a brief summary of neurotoxic pathogenetic mechanisms encompassing recent advances in the field, we focus on the clinical presentation of more common and severe immunosuppression-related neurological complications, classifying them by characteristics of urgency and anatomic site. Our goal is to provide a general framework that addresses such clinical issues with a multidisciplinary approach, as these conditions require.

Posterior reversible encephalopathy syndrome coexists with acute cerebral infarction: challenges of blood pressure management

Hypertension is the most common cause of posterior reversible encephalopathy syndrome (PRES) and acute cerebral infarction. Due to the lack of randomized controlled clinical trials (RCTs), early antihypertensive methods are diverse, even contradictory. So far, there is no consensus on the method of blood pressure (BP) management when the 2 diseases coexist. Generally, antihypertensive therapy should be initiated quickly in the acute phase of PRES, as most patients have elevated BP. However, various factors must be considered before the administration of early antihypertensive therapy in acute cerebral infarction. The coexistence of PRES and acute cerebral infarction is uncommon clinically, and more complicated subsequent BP management. This article reports a case of PRES coexisting with acute lacunar cerebral infarction, which was caused by hypertension. We have analyzed and summarized the antihypertensive principles in PRES and different phases of acute cerebral ischemic injury. We assert that when PRES and acute cerebral infarction coexist, the antihypertensive treatment should be individualized, and careful consideration should be given to the various influencing factors.

Intracranial Hypertension and Papilledema in a Large Cohort of Pediatric Patients With Alagille Syndrome

AIMS AND BACKGROUND

Ophthalmic abnormalities are amongst the 5 major criteria required for a diagnosis of Alagille syndrome (ALGS), of which embryotoxon, pseudopapilledema, and hypopigmented retinopathy are the most common. Papilledema with or without intracranial hypertension (ICHT) is rarely described. We report 9 pediatric cases of ALGS with bilateral papilledema, 5 of which were diagnosed with ICHT.

METHODS

The ophthalmic data from 85 patients with clinically and/or genetically (n = 37) proven ALGS were reviewed. The study inclusion criteria were a positive diagnosis of ALGS and availability of ophthalmic follow-up data. Ophthalmic data from 40 patients after liver transplantation (LT) for other indications were also analyzed.

RESULTS

Nine (13.0%) of the 69 patients meeting the inclusion criteria had papilledema. The neurological and neuroimaging results in all 9 patients were normal. These 9 patients were categorized into 4 groups: a nontransplant group (n = 1), a group with pretransplant papilledema persistent after LT (n = 2), a group with papilledema occurring after LT with spontaneous resolution (n = 1), and a group with papilledema and signs of ICHT after LT (n = 5). The patients with ICHT were treated with steroids alone (n = 1) or with acetazolamide (n = 4). A ventriculoperitoneal shunt was placed in 2 of the 5 cases because of progressive visual loss. Pseudopapilledema was present in 10 additional patients (14.5%, 10/69). One (2.5%) of the 40 patients without ALGS developed papilledema after LT.

CONCLUSIONS

True ICHT may be underdiagnosed in patients with ALGS. Our findings underscore the need for close ophthalmic follow-up before and after LT in these patients.

Cognitive Function in Kidney Transplantation

Purpose of the review

Cognitive impairment is common in kidney transplant recipients and affects quality of life, graft survival, morbidity, and mortality. In this review article we discuss the epidemiology, diagnosis, pathophysiology and future directions for cognitive impairment in kidney transplantation. We describe the potential role of pre-transplant cognition, immunosuppression and peri-transplant factors in post -transplant cognitive impairment.

Recent Findings

A majority of patients with kidney transplant have cognitive impairment. Cognitive impairment affects both pre-transplant evaluation and post-transplant outcomes. Failure to identify patients with cognitive impairment can withhold appropriate care and timely intervention.

Summary

Cognitive impairment is common in kidney transplant and affects outcomes. Studies addressing modifiable risk factors and possible interventions to slow cognitive decline in patients with kidney disease are needed.

Cerebellar Parieto-occipital Posterior Reversible Encephalopathy Syndrome and Cerebral Metamorphopsia Associated with Asymptomatic Atrial Septum Vegetation and Renal Disease: Case Report

Patient: Female, 25-year-old

Final Diagnosis: Posterior reversible encephalopathy syndrome

Symptoms: Visual disturbances

Medication: —

Clinical Procedure: —

Specialty: Neurology

Posterior reversible encephalopathy syndrome (PRES) after haploidentical haematopoietic stem cell transplantation: incidence, risk factors and outcomes

Posterior reversible encephalopathy syndrome (PRES) is a gradually recognised neurological complication of allogenic haematopoietic stem cell transplantation (allo-HSCT). However, there is a paucity of information on PRES after haploidentical HSCT (haplo-HSCT). We performed a retrospective nested case-control study in patients following haplo-HSCT for malignant and nonmalignant haematologic diseases between January 2009 and December 2018 in our centre. A total of 45 patients were diagnosed with PRES after transplant, accounting for an incidence of 1.17%. Grades II to IV acute graft-versus-host disease (aGVHD) (HR 2.370, 95% CI 1.277-4.397, p = 0.006) and hypertension (HR 14.466, 95% CI 7.107-29.443, p < 0.001) were identified as risk factors for developing PRES after haplo-HSCT. There was no difference in overall survival (OS), disease-free survival (DFS), the cumulative incidence of relapse or nonrelapse mortality (NRM) between patients with PRES and controls without PRES following haplo-HSCT in either adults or children. All but one patient with PRES showed nearly complete clinical and neurologic recovery. In conclusion, PRES is a rare condition with benign outcomes following haplo-HSCT. Further multicentre prospective studies are needed to confirm the results and help to establish the standard therapy for posttransplant PRES.

Catatonia Due to Tacrolimus Toxicity 16 Years After Renal Transplantation: Case Report and Literature Review

Tacrolimus, a potent posttransplant immunosuppressant, has been associated with major neuropsychiatric complications, including catatonia and psychosis. We report a novel case of tacrolimus-induced encephalopathy that developed 16 years after renal transplantation while the drug was at a therapeutic level. Discontinuation of tacrolimus and switching to an alternative immunosuppressant resulted in significant clinical improvement over 1 week. Our experience illustrates the possibility of acute neurotoxicity from tacrolimus even when the patient has tolerated the drug for 16 years and drug levels are within the therapeutic range. This case also highlights the importance of collaboration between psychiatry and transplant clinicians.

Posterior reversible encephalopathy syndrome concurrent with human herpesvirus-6B encephalitis after allogeneic hematopoietic stem cell transplantation

Posterior reversible encephalopathy syndrome (PRES) and human herpesvirus (HHV)-6 encephalitis are both serious neurological complications post hematopoietic stem cell transplantation. Although infection is one of the important causes of PRES, only few cases have reported the relation between PRES and viral infection. Herein, we report the first adult case of PRES concurrent with HHV-6 encephalitis after allogeneic hematopoietic stem cell transplantation for acute myeloid leukemia. This case suggests that HHV-6 reactivation is associated with the pathogenesis of PRES. Also, PRES and HHV-6 encephalitis cause similar symptoms, and switching the immunosuppressant from calcineurin inhibitor to prednisolone for treating PRES may worsen HHV-6 encephalitis. Therefore, we should pay attention to the complication of HHV-6 encephalitis even after PRES is diagnosed.

Posterior Reversible Encephalopathy Syndrome in a Five-Year-Old Child: A Case Report

Posterior reversible encephalopathy syndrome (PRES) is a neuroradiologic syndrome. The etiology of PRES is still unclear. Some factors were described. We present a case of a pediatric patient with liver transplant who developed PRES following blood transfusion while receiving tacrolimus therapy. A 5½-year-old boy who underwent living donor liver transplantation, and PRES developed on the sixth day post transplant under tacrolimus treatment after 6 hours of red blood transfusion. PRES is a rare condition; it should be kept in mind about patients who have received organ transplants and develop sudden neurologic symptoms.

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.

Neurologic complications of kidney transplantation

Renal transplant is the most common organ transplant in the United States, and the frequency of kidney transplants continues to rise as transplant offers improved survival and quality of life compared to dialysis. However, complications are not uncommon and patients frequently encounter issues requiring hospitalization, especially in the first year postoperatively. Complications that arise are typically related to surgical complications, immunosuppressive medications, or infection due to immunosuppression. Neurological complications are fairly common post-operatively, and are associated with increased morbidity and mortality in this population. This review discusses the most common etiologies of neurological complications after kidney transplant, including infection, malignancy, medication related, acute neuropathy, and other neurological pathology.

Complications of Stem Cell Transplantation that Affect Infections in Stem Cell Transplant Recipients, with Analogies to Patients with Hematologic Malignancies

This article discusses the complications of hematopoietic stem cell transplantion (HSCT) that affect infections in HSCT recipients, with analogies to patients with hematologic malignancies. Mucositis, with mucosal barrier disruption, is common and increases the risk of gram-positive and anaerobic bacterial, and fungal infections, and can evolve to typhlitis. Engraftment syndrome; graft-versus-host disease, hepatic sinusoidal obstruction syndrome; and posterior reversible encephalopathy syndrome can affect the infectious potential either directly from organ dysfunction or indirectly from specific treatment. Pulmonary infections can predispose to life threatening complications including diffuse alveolar hemorrhage, idiopathic pulmonary syndrome, bronchiolitis obliterans syndrome, and bronchiolitis obliterans with organizing pneumonia.

Tacrolimus-induced severe headache associated with diffuse leukoencephalopathy: Evidence for an immune-mediated pathogenesis

Tacrolimus-induced encephalopathy presents with acute neurological symptoms such as headache, seizures, visual disturbances, hemiplegia, and altered mental status. A 60-year-old woman, presented to our clinic with a 4-month history of severe headache. She recently underwent kidney transplantation and was taking tacrolimus. MRI scan showed diffuse and symmetric alterations involving both supratentorial and infratentorial white matter. Cerebral spinal fluid assessment for infectious diseases were negative but elevated total protein level and oligoclonal bands positivity were reported. Treatment with steroid bolus, along with tacrolimus tapering, provided clinico-radiological improvement. This is the first case of tacrolimus-induced neurotoxicity strongly suggestive of an immune-mediated pathogenesis.

Tuberculum sellae meningioma with possible tacrolimus neurotoxicity manifesting as manic-like psychosis after kidney transplantation

BACKGROUND

Although kidney transplantation is the best treatment option for chronic kidney disease, the accompanying immunosuppressive treatment can induce severe neurotoxicity presenting, on rare occasions, as psychosis. However, a brain tumor synchronous with immunosuppressant neurotoxicity has never been reported in a kidney transplant recipient. Herein, we report the first case of possible tacrolimus neurotoxicity with a meningioma manifesting as manic-like psychosis after kidney transplantation.

CASE PRESENTATION

A 63-year-old male presenting with acute psychotic mania was admitted to a psychiatric ward approximately 2 years after kidney transplantation. On brain magnetic resonance imaging, a tuberculum sellae meningioma was found, and hyperintense white matter lesions with possible tacrolimus-induced neurotoxicity were seen on fluid-attenuated inversion recovery images. Interestingly, the patient showed no visual field defects, and his blood tacrolimus concentration was within therapeutic ranges. After 3 weeks of adjunctive treatment with blonanserin, most of the symptoms had abated.

CONCLUSIONS

The present case highlights the fact that neuroimaging studies are necessary to investigate underlying causes, as well as immunosuppressant neurotoxicity, which should all be considered when atypical psychiatric symptoms develop after organ transplantation. Further, this case suggests that the additional use of atypical antipsychotics while maintaining immunosuppressants may be effective for manic-like psychotic symptoms secondary to possible immunosuppressant neurotoxicity synchronous with a meningioma.

Overdose of Tacrolimus as the Trigger Causing Progression of Posterior Reversible Encephalopathy Syndrome and Subsequent Hepatic Infarction After Liver Transplant: A Case Report

Posterior reversible encephalopathy syndrome is a neurotoxic state accompanied by unique brain imaging patterns and neurologic abnormalities, typically associated with several complex clinical conditions such as preeclampsia/eclampsia, solid-organ transplant procedures, autoimmune diseases, and immunosuppressive agents. The detailed mechanism of posterior reversible encephalopathy syndrome is not known, and the current therapy is only supportive care. Here, we present a 33-year-old parturient woman with preeclampsia complicated with hemolysis, elevated liver enzymes, and low platelet syndrome, fulminant hepatitis B, acute fatty liver, and posterior reversible encephalopathy syndrome. The patient developed gross hepatic infarction soon after liver transplant. After several possible causes were excluded, we found that progression of underlying posterior reversible encephalopathy syndrome-induced endothelial damage by overdose of tacrolimus may have been the major cause for deteriorating hypoperfusion of the transplanted liver and fatal graft failure. In liver transplant recipients, severe posttransplant hypoperfusion of the grafted liver may result in loss of the liver allograft and even mortality. Poor control of underlying posterior reversible encephalopathy syndrome-associated endothelial damage because of tacrolimus overdose may lead to severe hypoperfusion of grafted hepatic vessels and subsequent hepatic infarction. This report highlights tacrolimus as a potential trigger of posterior reversible encephalopathy syndrome and may inform clinical decisions regarding tacrolimus administration in liver transplant recipients with preexisting or newly developed posterior reversible encephalopathy syndrome.

Toxic-Metabolic Neurologic Disorders in Children: A Neuroimaging Review

There are multiple causes of neurotoxicity in children including medications, extrinsic toxins and insults, illicit drugs, built up of toxic metabolites due to genetic or acquired disorders, and metabolic abnormalities. The review is centered on causes of neurotoxicity affecting the pediatric brain and producing typical and easily recognized imaging manifestations. Early identification of common and less common imaging findings may point toward the correct direction, and may facilitate early diagnosis and institution of appropriate treatment to reverse or at least limit the injury to the developing brain. Two common imaging patterns of neurotoxicity in children are the posterior reversible encephalopathy syndrome and acute toxic leukoencephalopathy that are usually related to chemotherapy and immunosuppression for common pediatric malignancies. Another well-described imaging pattern of injury in children involves reversible splenial lesions with or without associated white matter abnormalities. Multiple additional extrinsic causes of neurotoxicity are presented including radiation and chemoradiation, various medications and treatment regimens, poisoning, illicit drug use or accidental exposure, and the respective characteristic neuroimaging findings are highlighted. Intrinsic neurotoxicity may occur in the setting of inborn errors of metabolism or acquired progressive organ failure leading to build up of toxic metabolites. Additional intrinsic causes of neurotoxicity include metabolic derangements and characteristic imaging findings in all instances are reviewed. The goal of the article is to enhance familiarity of neurologists and neuroradiologists with the imaging appearance of common and less common toxic insults to the pediatric brain.

A Late Complication Occurring Due to Tacrolimus After Liver Transplant: Posterior Reversible Encephalopathy Syndrome

Posterior reversible encephalopathy syndrome is a rare condition of the central nervous system that may occur in adults as well as in children. Clinically, it presents with mental status changes, visual loss, headaches, seizures, or coma. The diagnosis of posterior reversible encephalopathy syndrome is based on the typical appearance in occipital and parietal lobes in radiologic imaging studies, such as computed tomography or magnetic resonance imaging of the brain, which exhibit the typical appearance due to vasogenic edema. Causative factors include hypertensive encephalopathy, renal failure, preeclampsia, autoimmune conditions, and the use of cytotoxic or immunosuppressive agents. Rare cases of posterior reversible encephalopathy syndrome due to treatment with tacrolimus, an immunosuppressive agent commonly used after organ transplant, have been reported. In these patients, the tacrolimus dose is reduced or discontinued. In transplant patients with neurologic symptoms, the possibility of posterior reversible encephalopathy syndrome should be kept in mind.

High altitude trekking after lung transplantation: a prospective study using lung ultrasound to detect comets tails for interstitial pulmonary edema in lung transplant recipients and healthy volunteers

The intensity of physical activity which can be tolerated after lung transplantation and the tolerance to prolonged exercise at high altitude are poorly investigated. Lung ultrasound comet tails have been used in the diagnosis of interstitial pulmonary edema and high pulmonary altitude edema. The aim was to assess the number of lung ultrasound comet tails and to monitor changes in the optic nerve sheath diameter (ONSD) during a climb to the top of Mount Kilimanjaro in 10 lung transplant recipients and 10 healthy controls at three different altitude levels: 1360, 3505, 4900 m. Lung transplant recipients showed a constant increase in comet tail scores with altitude, whereas control subjects only showed an increase at the highest measurement point. Differences between groups (transplant versus control) reached significance only after the first ascend: 0.9 (95% CI: -0.41; 2.21) vs. 0.1 (95% CI: -0.12; 0.32) (P = 0.2; 1360 m), 2.33 (95% CI: 0.64; 4.02) vs. 0.3 (95% CI: -0.18; 0.78) (P = 0.04; 3505 m), and 4.11 (95% CI: 0.13; 0.34) vs. 2.9 (95% CI: 0.49; 5.31) (P = 0.15; 4900 m); ONSD increased significantly in both groups from 3.53 (95% CI: 0.34; 0.66) at 1360 m to 4.11 (95% CI: 0.36; 0.71) at 4900 m (P < 0.05). Lungs of transplant recipients are able to adapt to altitude and capable of performing prolonged exercise at high altitude after slow ascend.

Posterior reversible leukoencephalopathy syndrome (PRES) after kidney transplantation: a case report

INTRODUCTION

Posterior reversible leukoencephalopathy syndrome (PRES) was first described by Hinchey in 1996. The syndrome is characterized by altered level of consciousness, headache, visual changes, and seizures associated with a vasogenic edema of the white matter that occurs predominantly in the occipital and parietal lobes. Imaging tests such as computed tomography (CT) and especially magnetic resonance imaging (MRI) support the diagnosis.

CASE REPORT

We report a case of a 48-year-old female patient who underwent a deceased donor kidney transplant and received tacrolimus as a part of the immunosuppressive regimen. Five weeks after transplantation she was admitted to the emergency due to sudden onset of confusion, disorientation, visual disturbances, and major headache. PRES was suspected and the diagnosis confirmed by brain MRI. Tacrolimus was withdrawn and rapid improvement of the neurological signs occurred leading to the conclusion that this drug triggered the syndrome.

CONCLUSION

PRES is an unusual complication after organ transplantation and should be considered in the appropriate clinical setting. Physicians must be aware of this condition in order to provide early detection and appropriate treatment since delay in removing the cause may lead to permanent sequelae.

Hyperammonemia Presenting as Refractory Status Epilepticus after Lung Transplant in a Patient Positive for Ureaplasma parvum

Hyperammonemia is a rare complication of lung transplant with a high mortality rate. It presents as encephalopathy and progresses to seizures, status epilepticus, coma, cerebral edema, and brain death. Multiple treatments have been documented including administration of medications, gut decontamination, and dialysis. However, no definitive treatments exist and mortality remains between 67% and 75%. We present the case of a 65-year-old male with idiopathic pulmonary fibrosis who developed refractory status epilepticus secondary to hyperammonemia following lung transplant. The patient presented on postoperative day 7 with super-refractory status epilepticus and normal computed tomography scan of the head. Hyperammonemia was suspected due to refractory seizures and confirmed with peak ammonia level >1000 μmol/L. Despite aggressive treatment, the patient developed global cerebral edema and died. Postmortem investigations revealed that the patient was positive for Ureaplasma parvum. Additional studies are needed to elucidate the exact mechanism of disease and investigate successful treatment options.

Low-dose tacrolimus combined with donor-derived mesenchymal stem cells after renal transplantation: a prospective, non-randomized study

Calcineurin inhibitors, including tacrolimus, are largely responsible for advances in allotransplantation. However, the nephrotoxicity associated with these immunosuppressants impairs patients' long-term survival after renal allograft. Therefore, novel regimens that minimize or even eliminate calcineurin inhibitors could improve transplantation outcomes. In this pilot study, we investigated the use of low-dose tacrolimus in combination with mesenchymal stem cells (MSCs), which are immunosuppressive and prolong allograft survival in experimental organ transplant models. Donor-derived, bone marrow MSCs combined with a sparing dose of tacrolimus (0.04-0.05 mg/kg/day) were administered to 16 de novo living-related kidney transplant recipients; 16 other patients received a standard dose of tacrolimus (0.07-0.08 mg/kg/day). The safety of MSC infusion, acute rejection, graft function, graft survival, and patient survival were evaluated over ≥24 months following kidney transplantation. All patients survived and had stable renal function at the 24 month follow-up. The combination of low-dose tacrolimus and MSCs was as effective as standard dose tacrolimus in maintaining graft survival at least 2 years after transplantation. In addition, both groups had similar urea, urine protein, urinary RBC, urinary WBC, 24-h urine protein, and creatinine clearance rates from 7 days to 24 months after transplantation. Furthermore, no differences in the proportion of lymphocytes, CD19, CD3, CD34, CD38, and natural killer cells were detected between the control and experimental groups. None of the MSC recipients experienced immediate or long-term toxicity from the treatment. This preliminary data suggests that the addition of MSCs permits the use of lower dosages of nephrotoxic calcineurin inhibitors following renal transplantation.

Overview of Immunosuppressive Therapy in Solid Organ Transplantation

Mechanisms of rejection, new pharmacologic approaches, and genomic medicine are major foci for current research in transplantation. It is hoped that these new agents and personalized immunosuppression will provide for less toxic regimens that are effective in preventing both acute and chronic allograft rejection. Until new agents are available, practitioners must use various combinations of currently approved agents to find the best regimens for improved long-term outcomes.

Ocular Dysfunctions Presenting in Tacrolimus-Induced Posterior Reversible Encephalopathy Syndrome: A Case Presentation

The constellation of ocular symptoms known as Balint syndrome is a rare disorder seen in bilateral parieto-occipital lesions and is most frequently due to arterial occlusive disease or acute hypertension. Here we present the case of a patient with tacrolimus-induced posterior reversible encephalopathy syndrome (PRES) who presented with optic ataxia, simultanagnosia, and ocular apraxia. These ocular findings, consistent with Balint syndrome, are rarely the initial presentation of PRES. This case highlights the importance of early recognition of this unusual phenomenon, as well as the importance of an individualized rehabilitation plan to maximize functional independence in these patients.

LEVEL OF EVIDENCE

V.

Posterior Reversible Encephalopathy Syndrome After Orthotopic Heart Transplantation: A Case Report

BACKGROUND Calcineurin inhibitor-induced posterior reversible encephalopathy syndrome (PRES) is well described in liver and kidney transplant patients, but there is a paucity of data in heart transplant patients. PRES syndrome in the setting of heart transplantation can occur as early as 5 days following transplantation. CASE REPORT A 32-year-old woman who had recently undergone orthotopic heart transplantation developed headaches, visual disturbances, and generalized tonic clonic seizures 5 days after initiating anti-rejection therapy (tacrolimus, mycophenolate, and prednisone). No focal neurological deficits were noted on physical exam. Multifocal subcortical fluid attenuation inversion recovery (FLAIR) hyperintensity signals and areas of diffusion restriction with postcontrast enhancement, diagnostic of PRES, were found on MRI brain. Her symptoms resolved 2 days after tacrolimus was switched to cyclosporine. A follow-up MRI after 6 weeks demonstrated complete resolution of areas of flair hyperintensity signal. She was sent home on a short course of seizure prophylaxis, which was discontinued after the resolution of radiological findings. She had no further episodes of seizures for 6 months following discontinuation of her anti-epileptic regimen. CONCLUSIONS Tacrolimus-induced PRES can occur as early as 5 days after orthotopic heart transplantation. Early recognition of symptoms and management can prevent permanent neurological sequelae.

Posterior reversible encephalopathy syndrome

The posterior reversible encephalopathy syndrome (PRES) is a neurological disorder of (sub)acute onset characterized by varied neurological symptoms, which may include headache, impaired visual acuity or visual field deficits, disorders of consciousness, confusion, seizures, and focal neurological deficits. In a majority of patients the clinical presentation includes elevated arterial blood pressure up to hypertensive emergencies. Neuroimaging, in particular magnetic resonance imaging, frequently shows a distinctive parieto-occipital pattern with a symmetric distribution of changes reflecting vasogenic edema. PRES frequently develops in the context of cytotoxic medication, (pre)eclampsia, sepsis, renal disease or autoimmune disorders. The treatment is symptomatic and is determined by the underlying condition. The overall prognosis is favorable, since clinical symptoms as well as imaging lesions are reversible in most patients. However, neurological sequelae including long-term epilepsy may persist in individual cases.

Posterior reversible encephalopathy in the intensive care unit

Posterior reversible encephalopathy syndrome (PRES) is increasingly diagnosed in the emergency department, and medical and surgical intensive care units. PRES is characterized by acute onset of neurologic symptoms in the setting of blood pressure fluctuations, eclampsia, autoimmune disease, transplantation, renal failure, or exposure to immunosuppressive or cytotoxic drugs, triggers known to admit patients to the intensive care unit (ICU). Although the exact pathophysiology remains unknown, there is growing consensus that PRES results from endothelial dysfunction. Because of the heterogeneous nature of the disorder, it is probable that different mechanisms of endothelial injury are etiologically important in different clinical situations. The presence of bilateral vasogenic edema on brain imaging, particularly in parieto-occipital regions, is of great diagnostic utility but PRES remains a clinical diagnosis. Although largely reversible, PRES can result in irreversible neurologic injury and even death. The range of clinical and radiographic manifestations of the syndrome is probably broader than previously thought, and it is imperative that clinicians become familiar with the full spectrum of the disorder, as prompt recognition and elimination of an inciting factor improve outcome. PRES may be the most frequent toxic-metabolic encephalopathy seen in the ICU.

New perspectives on the use of mTOR inhibitors in allogeneic haematopoietic stem cell transplantation and graft-versus-host disease

Inhibition of the mechanistic target of rapamycin (mTOR) has been exploited largely both in solid tumour oncology and solid organ transplantation. More recently mTOR inhibitors such as sirolimus and everolimus have been introduced to the field of allogeneic haematopoietic stem cell transplantation where their unique combination of immunosuppressive purposes offering reduced nephrotoxicity and potential antimalignant effects reflect a unique drug profile that has led to their widespread use in both prophylaxis and therapy of graft-versus-host disease (GVHD). On the other hand haematological insufficiency, infectious complications as well as vasculopathies, have been frequently reported as limiting toxicities. Here, we review both the retrospective and prospective experience available to date and stress the need for prospective registration trials to reduce off label use and improve patient safety by optimizing dosing and enhancing pharmacovigilance. Furthermore, we speculate on the future role of mTOR inhibitors in allogeneic haematopoietic stem cell transplantation.

The phosphatase calcineurin regulates pathological TDP-43 phosphorylation

Detergent insoluble inclusions of TDP-43 protein are hallmarks of the neuropathology in over 90 % of amyotrophic lateral sclerosis (ALS) cases and approximately half of frontotemporal dementia (FTLD-TDP) cases. In TDP-43 proteinopathy disorders, lesions containing aggregated TDP-43 protein are extensively post-translationally modified, with phosphorylated TDP-43 (pTDP) being the most consistent and robust marker of pathological TDP-43 deposition. Abnormally phosphorylated TDP-43 has been hypothesized to mediate TDP-43 toxicity in many neurodegenerative disease models. To date, several different kinases have been implicated in the genesis of pTDP, but no phosphatases have been shown to reverse pathological TDP-43 phosphorylation. We have identified the phosphatase calcineurin as an enzyme binding to and catalyzing the removal of pathological C-terminal phosphorylation of TDP-43 in vitro. In C. elegans models of TDP-43 proteinopathy, genetic elimination of calcineurin results in accumulation of excess pTDP, exacerbated motor dysfunction, and accelerated neurodegenerative changes. In cultured human cells, treatment with FK506 (tacrolimus), a calcineurin inhibitor, results in accumulation of pTDP species. Lastly, calcineurin co-localizes with pTDP in degenerating areas of the central nervous system in subjects with FTLD-TDP and ALS. Taken together, these findings suggest calcineurin acts on pTDP as a phosphatase in neurons. Furthermore, patient treatment with calcineurin inhibitors may have unappreciated adverse neuropathological consequences.

Cognitive Changes in Chronic Kidney Disease and After Transplantation

Cognitive impairment is very common in chronic kidney disease (CKD) and is strongly associated with increased mortality. This review article will discuss the pathophysiology of cognitive impairment in CKD, as well as the effect of dialysis and transplantation on cognitive function. In CKD, uremic toxins, hyperparathyroidism and Klotho deficiency lead to chronic inflammation, endothelial dysfunction and vascular calcifications. This results in an increased burden of cerebrovascular disease in CKD patients, who consistently have more white matter hyperintensities, microbleeds, microinfarctions and cerebral atrophy on magnetic resonance imaging scans. Hemodialysis, although beneficial in terms of uremic toxin clearance, also contributes to cognitive decline by causing rapid fluid and osmotic shifts. Decreasing the dialysate temperature and increasing total dialysis time limits these shifts and helps maintain cognitive function in hemodialysis patients. For many patients, kidney transplantation is the preferred treatment modality, because it reverses the underlying mechanisms causing cognitive impairment in CKD. These positive effects have to be balanced against the possible neurotoxicity of infections and immunosuppressive medications, especially glucocorticosteroids and calcineurin inhibitors. A limited number of studies have addressed the overall effect of transplantation on cognitive function. These have mostly found an improvement after transplantation, but have a limited applicability to daily practice because they have only included relatively young patients.

Practice Guidelines for the Diagnosis and Management of Aspergillosis: 2016 Update by the Infectious Diseases Society of America

It is important to realize that guidelines cannot always account for individual variation among patients. They are not intended to supplant physician judgment with respect to particular patients or special clinical situations. IDSA considers adherence to these guidelines to be voluntary, with the ultimate determination regarding their application to be made by the physician in the light of each patient's individual circumstances.

Acute Respiratory Distress Syndrome and Posterior Reversible Encephalopathy Syndrome following Rituximab Therapy

The anti-CD20 monoclonal antibody rituximab is associated with rare but significant adverse events, notably posterior reversible encephalopathy syndrome (PRES) and acute respiratory distress syndrome (ARDS). We report a case of concomitant ARDS and PRES developing after rituximab therapy for treatment of cryoglobulinaemic vasculitis. There are 7 reported cases of PRES complicating rituximab use. PRES onset varied from immediate to 21 days after administration. All patients recovered completely, and rituximab was reintroduced in half of the cases. The occurrence of ARDS in association with rituximab is rarer. Only 3 confirmed cases exist, and ARDS may occur as a delayed reaction.

[Posterior reversible encephalopathy syndrome]

Posterior reversible encephalopathy syndrome refers to a neurological disorder characterized by headache, disorders of consciousness, visual disturbances, epileptic seizures, and subcortical vasogenic edema. About two thirds of patients develop neurological symptoms, which are associated with blood pressure fluctuations. One hypothesis is that hypertensive episodes cause autoregulatory failure, and values above the upper limit of cerebral autoregulation result in a breakthrough followed by hyperperfusion and blood-brain barrier dysfunction. In another hypothesis, endothelial dysfunction triggered by numerous factors including preeclampsia, immunosuppressive agents, chemotherapeutics, sepsis, or autoimmune disorders is thought to be the key pathomechanism. Endo- or exogenic toxic agents including pharmacological substances, cytokines, or bacterial toxins are supposed to trigger endothelial activation and dysfunction resulting in the release of vasoconstrictors, pro-inflammatory mediators, and vascular leakage. Diagnosis is usually based on clinical and neuroimaging findings that frequently show a bilateral, symmetric, and parietooccipital pattern. However, the diagnosis can often only be confirmed during the course of disease after excluding important differential diagnoses. Currently, there is no specific treatment available. Lowering of arterial blood pressure and eliminating the underlying cause usually leads to an improvement of clinical and neuroradiological findings. Admission to a critical care unit is required in about 40 % of patients due to complicating conditions including status epilepticus, cerebral vasoconstriction, ischemia, or intracerebral hemorrhage. Prognosis is favorable; in the majority of patients neurological deficits and imaging findings resolve completely.