Tacrolimus (FK506)-induced severe and late encephalopathy in a renal transplant recipient

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.

Immunosuppressant Tacrolimus Treatment Delays Acute Seizure Occurrence, Reduces Elevated Oxidative Stress, and Reverses PGF2α Burst in the Brain of PTZ-Treated Rats

It is still an urgent need to find alternative and effective therapies to combat epileptic seizures. Tacrolimus as a potent immunosuppressant and calcineurin inhibitor is emerging as promising drug to suppress seizures. However, there are few reports applying tacrolimus to epilepsy and providing data for its antiseizure properties. In this study, we investigated the antiseizure effects of 5 and 10 mg/kg doses of tacrolimus treatment priorly to pentylenetetrazol (PTZ) induction of seizures in rats. As an experimental design, we establish two independent rat groups where we observe convulsive seizures following 70 mg/kg PTZ and sub-convulsive seizures detected by electroencephalography (EEG) following 35 mg/kg PTZ. Thereafter, we proceed with biochemical analyses of the brain including assessment of malondialdehyde level as an indicator of lipid peroxidation and detection of superoxide dismutase (SOD) enzyme activity and PGF2α. Tacrolimus pre-treatment dose-dependently resulted in lesser seizure severity according to Racine's scale, delayed start-up latency of the first myoclonic jerk and attenuated the spike percentages detected by EEG in seizure-induced rats. However, only the higher dose of tacrolimus was effective to restore lipid peroxidation. An increase in SOD activity was observed in the PTZ group, mediated by seizure activity per se, however, it was greater in the groups that received treatment with 5 and 10 mg/kg of Tacrolimus. PGF2α bursts following PTZ induction of seizures were reversed by tacrolimus pre-treatment in a dose-dependent manner as well. We report that the well-known immunosuppressant tacrolimus is a promising agent to suppress seizures. Comparative studies are necessary to determine the possible utilization of tacrolimus in clinical cases.

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.

Seizure outcomes of posterior reversible encephalopathy syndrome and correlations with electroencephalographic changes

RATIONALE

Seizures are among the most common clinical presentations of posterior reversible encephalopathy syndrome (PRES). This syndrome has rarely been reported to cause chronic epilepsy or persistent cortical dysfunction. The prognostic value of EEG findings during PRES is unknown. We retrospectively evaluated EEG characteristics in patients with PRES in a single medical center. We also evaluated the long-term outcome regarding seizure occurrence beyond the acute phase in these patients.

METHODS

We searched a radiology database at the University of Minnesota from 1997 to 2012 to identify patients with clinically and radiologically diagnosed PRES. Among the patients with PRES, we reviewed MRI images, EEG findings, clinical manifestations including seizure occurrences, and clinical outcomes beyond the acute phase.

RESULTS

Seventy-five patients were included in the study. Fifty-eight out of seventy-five (77.3%) patients with PRES had seizures. A total of 48 EEG studies were performed in 38 patients. Generalized slowing was the most common EEG pattern. Among the 38 patients who had EEGs, 37 (97.3%) patients had diffuse or focal slowing of the background, and 11 (28.9%) patients had IEDs. Four out of seventy-five (5.3%) patients had seizures later than one month beyond their hospitalization for PRES. None of these 4 patients had seizures before the episode of PRES. Two patients developed chronic epilepsy, with seizures occurring later than one year after the PRES.

CONCLUSION

Most patients who had seizures or who had epileptiform activities in EEG during PRES did not subsequently develop chronic epilepsy. No patient developed chronic epilepsy in the absence of clinical seizures during PRES. Posterior reversible encephalopathy syndrome may infrequently be associated with subsequent development of symptomatic epilepsy.

Cyclosporin A enhances neural precursor cell survival in mice through a calcineurin-independent pathway

Cyclosporin A (CsA) has direct effects on neural stem and progenitor cells (together termed neural precursor cells; NPCs) in the adult central nervous system. Administration of CsA in vitro or in vivo promotes the survival of NPCs and expands the pools of NPCs in mice. Moreover, CsA administration is effective in promoting NPC activation, tissue repair and functional recovery in a mouse model of cortical stroke. The mechanism(s) by which CsA mediates this cell survival effect remains unknown. Herein, we examined both calcineurin-dependent and calcineurin-independent pathways through which CsA might mediate NPC survival. To examine calcineurin-dependent pathways, we utilized FK506 (Tacrolimus), an immunosuppressive molecule that inhibits calcineurin, as well as drugs that inhibit cyclophilin A-mediated activation of calcineurin. To evaluate the calcineurin-independent pathway, we utilized NIM811, a non-immunosuppressive CsA analog that functions independently of calcineurin by blocking mitochondrial permeability transition pore formation. We found that only NIM811 can entirely account for the pro-survival effects of CsA on NPCs. Indeed, blocking signaling pathways downstream of calcineurin activation using nNOS mice did not inhibit CsA-mediated cell survival, which supports the proposal that the effects are calcinuerin-independent. In vivo studies revealed that NIM811 administration mimics the pro-survival effects of CsA on NPCs and promotes functional recovery in a model of cortical stroke, identical to the effects seen with CsA administration. We conclude that CsA mediates its effect on NPC survival through calcineurin-independent inhibition of mitochondrial permeability transition pore formation and suggest that this pathway has potential therapeutic benefits for developing NPC-mediated cell replacement strategies.

Pharmacotherapy of traumatic brain injury: state of the science and the road forward: report of the Department of Defense Neurotrauma Pharmacology Workgroup

Despite substantial investments by government, philanthropic, and commercial sources over the past several decades, traumatic brain injury (TBI) remains an unmet medical need and a major source of disability and mortality in both developed and developing societies. The U.S. Department of Defense neurotrauma research portfolio contains more than 500 research projects funded at more than $700 million and is aimed at developing interventions that mitigate the effects of trauma to the nervous system and lead to improved quality of life outcomes. A key area of this portfolio focuses on the need for effective pharmacological approaches for treating patients with TBI and its associated symptoms. The Neurotrauma Pharmacology Workgroup was established by the U.S. Army Medical Research and Materiel Command (USAMRMC) with the overarching goal of providing a strategic research plan for developing pharmacological treatments that improve clinical outcomes after TBI. To inform this plan, the Workgroup (a) assessed the current state of the science and ongoing research and (b) identified research gaps to inform future development of research priorities for the neurotrauma research portfolio. The Workgroup identified the six most critical research priority areas in the field of pharmacological treatment for persons with TBI. The priority areas represent parallel efforts needed to advance clinical care; each requires independent effort and sufficient investment. These priority areas will help the USAMRMC and other funding agencies strategically guide their research portfolios to ensure the development of effective pharmacological approaches for treating patients with TBI.

Tacrolimus associated posterior reversible encephalopathy syndrome - a case series and review

Tacrolimus is an immunosuppressive drug mainly used to lower the risk of transplant rejection in individuals who are post solid organ or hematopoietic transplantation. It is a macrolide which reduces peptidyl-propyl isomerase activity and inhibits calcineurin, thus inhibiting T-lymphocyte signal transduction and interleukin-2 (IL-2) transcription. It has been associated with Posterior Reversible Encephalopathy Syndrome (PRES), a disease of sudden onset that can present as a host of different symptoms, depending on the affected area of the brain. While infectious causes of encephalopathy must always be entertained, the differential diagnosis should also include PRES in the appropriate context. We report three cases of PRES in patients with acute myeloid leukemia (AML) placed on tacrolimus after receiving a bone marrow transplant (BMT). The focus of this review is to enhance clinical recognition of PRES as it is related to an adverse effect of Tacrolimus in the setting of hematopoietic transplantation.

Posterior reversible encephalopathy syndrome (PRES): electroencephalographic findings and seizure patterns

To better describe seizure type, frequency, and electroencephalographic (EEG) findings in posterior reversible encephalopathy syndrome (PRES) and correlate these data with clinical and magnetic resonance imaging (MRI) data, we retrospectively assessed medical charts and EEG studies of patients with PRES treated between 2004 and 2011. Data collected included patients' underlying pathology, lesion distribution by MRI, seizure type and frequency, EEG pathologic background activity, focal pathology, and epileptogenic activity. Thirty-eight of 49 adults with PRES suffered from seizures; 17 underwent EEG and were included in the analysis. Perpetuating factors were similar to those reported in the literature. In 15 of 17 patients, MRI showed widespread involvement rather than purely occipital lesions. Nine patients had subcortical and cortical involvement. Seizures were single short grand mal (GM) in 11, serial GM in 2, recurrent GM in 2, and additional focal seizures in 2. No seizures were noted beyond the first day. After discontinuation of antiepileptic medication, no patients experienced seizure recurrence during 6-month follow-up. EEG showed diffuse theta/delta slowing in 13 patients and epileptogenic activity with focal sharp-wave and periodic lateralizing epileptiform discharges in 2 patients. Seizures in PRES are most commonly single GM and are usually of limited duration. EEG shows variable theta/delta slowing. Focal EEG pathology is seen in patients with focal seizures. Seizures occur early after disease onset and terminate spontaneously or under therapy during the first 24 h. Seizure recurrence beyond 24 h and chronic epilepsy were not seen. Seizures in PRES are frequent but appear to be uncomplicated and do not herald worse prognosis. EEG is helpful in evaluating the degree of encephalopathy and monitoring epileptic activity. Long-term antiepileptic medication does not appear to be warranted.

Transient Ischemic Attack After Rizatriptan Administration in a Liver Transplant Recipient: A Case Report

We report the case of a male liver transplant recipient who developed de novo migraine while on tacrolimus therapy. Considering the inadequate control of pain using nonsteroidal antiinflammatory drugs, rizatriptan benzoate (10 mg orally) was administered (double administration). After both administrations a clinically transient ischemic attack (TIA) occurred. Rizatriptan was discontinued, the patient recovered without sequelae from both episodes of TIA. Remission of migraine occurred after discontinuation of tacrolimus and substitution with cyclosporine. We suggest that the association of rizatriptan and tacrolimus could potentially lead to an excessive risk of cerebral vasospasm and should be used with caution. A change in immunosuppressive therapy (from tacrolimus to cyclosporine or sirolimus) may improve migraine and should be the first choice. Further prospective comparative randomized trials are needed to establish the best therapeutic option in this particular subset of patients.

Pleocytosis after hemopoietic stem cell transplantation

Frequency and clinical significance of cerebrospinal fluid (CSF) pleocytosis in hemopoietic stem cell (HSC) transplantation were surveyed. Cyclosporine (CSA)- or tacrolimus (FK506)-based regimens were used as graft-vs-host disease (GVHD) prophylaxis in allogeneic HSC transplantation. CSF pleocytosis with or without neurologic symptoms was detected in 12 of 25 patients receiving allogeneic HSC transplants but in none of 11 patients receiving autologous HSC transplants. Of the 12 patients with CSF pleocytosis, only one patient developed leukoencephalopathy later. There was a correlation between CSF cell numbers and trough levels of CSA but not with those of FK506. In patients receiving allogeneic HSC transplants, CSF pleocytosis may be relatively common and may reflect neurologic damage associated with calcineurin inhibitors.

Electroencephalographic (EEG) findings in posterior reversible encephalopathy associated with immunosuppressants

Posterior reversible encephalopathy has been reported in patients who receive immunosuppressants. Compared with radiologic studies, electroencephalographic (EEG) findings are not well described. We performed EEG serially in three children who suffered from posterior reversible encephalopathy associated with tacrolimus or cyclosporine. EEG showed continuous focal rhythmic activities in the acute period. EEG findings normalized after the clinical manifestations had disappeared. We conclude that EEG is useful for the diagnosis and follow-up of posterior reversible encephalopathy.

Progressive neurological disease induced by tacrolimus in a renal transplant recipient: case presentation

Background

Tacrolimus and cyclosporine, both calcineurin inhibitors, can cause neurological side effects. While mild symptoms such as tremor are well recognised, severe complications including seizures and encephalopathy are poorly documented following renal transplantation.

Case presentation

We report a 42 year old man who received a cadaver renal transplant. He received tacrolimus and prednisolone. The course was uneventful for 6 weeks when he became intermittently confused, with unsteady gait and slurred speech. Following a grand mal convulsion he was admitted. He had no focal neurological signs, cerebrospinal fluid was normal; electroencephalogram was consistent with temporal lobe partial epilepsy. The magnetic resonance imaging of brain showed widespread changes with multiple areas of low signal intensity in brain stem and cerebral hemispheres. He was readmitted 3 weeks later after further fits, despite anti-convulsant therapy. He was psychotic with visual hallucinations, and rapidly became obtunded. Although his tacrolimus blood concentration had been kept in the normal range, his symptoms improved dramatically when the tacrolimus was stopped.

Conclusion

Severe central nervous system toxicity from calcineurin inhibitors has been rarely reported in renal transplantation and we found only one report of tacrolimus-induced toxicity in an adult. We believe the condition is frequently undiagnosed. It is a very important diagnosis not to miss as the remedy is simple and failure may result in unnecessary brain biopsy, as well as irreversible injury.

Tacrolimus-Related Encephalopathy following Allogeneic Stem Cell Transplantation in Children

Tacrolimus is a potent immunosuppressive drug widely used to prevent and treat graft-versus-host disease (GVHD) in stem cell transplantation (SCT). Among 49 patients receiving tacrolimus who underwent SCT from January 2000 to July 2003, 10 patients (20%) developed encephalopathy. The commonly observed symptoms were convulsions and drowsiness, and most patients complained of signal symptoms such as headache, nausea, and cortical blindness before onset. The most common abnormality on neuroimages was high-intensity lesions in white matter on magnetic resonance imaging T2-weighted or fluid-attenuated inversion recovery images. At onset, all patients were receiving treatment for acute GVHD (grade II/III) or extensive chronic GVHD and demonstrated an abrupt increase in blood pressure from baseline levels. The serum tacrolimus concentration was generally within acceptable levels at onset. Symptoms gradually improved in all patients when the blood pressure was lowered with antihypertensive medication, regardless of continued tacrolimus administration following a short-term suspension. The pathogenesis of tacrolimus-related encephalopathy is multifactorial, although refractory GVHD and a sudden increase in blood pressure seem to be major predisposing factors. Because the withdrawal of tacrolimus or switching to less potent anti-GVHD agents usually worsens the GVHD, the administration of tacrolimus should be managed by closely monitoring serum levels and controlling blood pressure.

Tacrolimus-associated posterior reversible encephalopathy syndrome after allogeneic haematopoietic stem cell transplantation

Neurotoxicity is a significant complication of the use of tacrolimus. From April 1998 to December 2001, we identified 10 patients (six women, four men) who developed 11 episodes of tacrolimus-associated posterior reversible encephalopathy syndrome (PRES) after allogeneic haematopoietic stem cell transplantation for haematological malignancies. The diagnosis was made by characteristic clinical findings (mental status changes, seizures, neurological deficits) with the exclusion of other causes and characteristic imaging findings. The median age was 35.5 years (range 19-57 years). Seven patients received a matched-unrelated donor transplant and three received a cord blood transplant. The overall incidence of PRES was 1.6%, while the incidence in matched-unrelated, mismatched-related and cord blood transplants was 3.5%, 4.9% and 7.1% respectively. Mental status changes, cognitive deficits, seizures and lethargy were the most common clinical findings. Eight of 10 patients had characteristic findings of hyperintensity of the white matter on T2-weighted images and FLAIR (fluid-attenuated inversion recovery) sequence on magnetic resonance imaging of the brain. Serum tacrolimus levels were within the therapeutic range in most patients. Tacrolimus treatment was continued (n = 4) or temporarily withheld (n = 7) for 1-14 d. One patient was changed to cyclosporine. In most patients, subsequent treatment with tacrolimus was well tolerated without recurrence of neurotoxicity.

Neuropsychologic side-effects of tacrolimus in pediatric renal transplantation

Calcineurin inhibition with tacrolimus has been used after renal transplantation (RTPL) as rescue therapy for insufficient immunological control or if cyclosporin A (CSA) toxicity occurred. Neurologic side-effects occur but are rare in children, usually presenting as tremor; however, serious complications, e.g. the posterior leukoencephalopathy syndrome are also documented. Twenty children (10 girls) were switched to tacrolimus: 11 (55%) for immunological reasons (n = 9: steroid-resistant rejection; n = 2: recurrent rejections) and nine for CSA side-effects. Tacrolimus was started at a median of 8 wk (range 10 d to 8.7 yr) after RTPL and was continued for a median of 2.5 yr (range 5 wk to 4.6 yr). Renal function significantly improved over a period of 12 months following conversion to tacrolimus (glomerular filtration rate 56 +/- 19 vs. 66 +/- 16 mL/min/1.73 m2; p < 0.03; n = 13). Fifteen of 20 (75%) patients tolerated tacrolimus well. The most frequent side-effects were neuropsychological and behavioral symptoms in three children, ranging from anorexia nervosa-like symptoms with weight loss, amenorrhea, depression and school problems to severe insomnia and to aggressive and anxious behavior in one child. Only the latter child was exposed to toxic tacrolimus blood levels. All side-effects were fully reversible after discontinuation of tacrolimus. In conclusion, tacrolimus had a beneficial effect on renal function and was well tolerated in the majority of pediatric patients. However, neuropsychologic and behavioral side-effects are important and maybe underrecognized in children.