Successful treatment of non-HIV progressive multifocal leukoencephalopathy: case report and literature review

John Cunningham Virus and Progressive Multifocal Leukoencephalopathy: A Falsely Played Diagnosis

Progressive Multifocal Leukoencephalopathy (PML) is a possibly fatal demyelinating disease and John Cunningham Polyomavirus (JCPyV) is believed to cause this condition. The so-called JCPyV was initially reported in lymphoma and Human Immunodeficiency Virus (HIV) cases, whereas nowadays, its incidence is increasing in Multiple Sclerosis (MS) cases treated with natalizumab (Tysabri). However, there are conflicting literature data on its pathology and diagnosis, whereas some misdiagnosed reports exist, giving rise to further questions towards the topic. In reality, the so-called PML and the supposed JCPyV are not what they seem to be. In addition, novel and more frequent PML-like conditions may be reported, especially after the Coronavirus Disease 2019 (COVID-19) pandemic.

Inflammatory progressive multifocal leukoencephalopathy with human T-cell lymphotropic virus-1 coinfection

A middle-aged man with progressive multifocal leukoencephalopathy (PML) in a human T-cell lymphotropic virus type-1 (HTLV-1) carrier on haemodialysis presented with mild dysarthria and ataxia. Brain MRI revealed asymmetric T2-hyperintense lesions in the cerebral white matter, cerebellum and brainstem. A small amount of JC virus (JCV) genome in cerebrospinal fluid was detected by PCR and cerebellar biopsy demonstrated JCV-DNA presence. Pathological findings showed demyelinating lesions and glial cells with mildly enlarged nuclei, accompanied by T-lymphocytes, neutrophils and plasma cell infiltration. The CD4+/CD8+ratio was 0.83. High-dose corticosteroid therapy was effective for inflammatory PML lesions, and the administration of mefloquine combined with mirtazapine led to favourable outcome. The encephalitis in this case is considered to have occurred secondarily to JCV infection in the presence of HTLV-1 infection. Therefore, it is crucial to investigate the presence of HTLV-1 in order to understand the aetiology of this brain inflammation.

Pathology for severe inflammatory PML with PD1/PD-L1 expression of favorable prognosis: What's a prognostic factor for PML-IRIS?

A 72-year-old woman with dermatomyositis (DM) developed neurological manifestation, and magnetic resonance imaging (MRI) revealed multiple T2/fluid-attenuated inversion recovery (FLAIR)-hyperintense lesions predominantly in the deep white matter of the cerebral hemisphere. Punctate or linear contrast enhancement was observed surrounding the T1-hypointense area. Multiple T2/FLAIR-hyperintense lesions were aligned along with the corona radiata. Malignant lymphoma was first suspected, and a brain biopsy was performed. Pathological investigation suggested the provisional diagnosis of "suspicious of malignant lymphoma." Owing to emergent clinical conditions, high-dose methotrexate (MTX) therapy was conducted, and then T2/FLAIR-hyperintense lesions were dramatically reduced. However, the diagnosis of malignant lymphoma was concerning since multiplex PCR demonstrated clonal restriction of the Ig H gene for B cells and TCR beta genes for T cells. Histopathology revealed the infiltration of both CD4+ and CD8+ T cells, and the CD4+ /CD8+ ratio was 4.0. Moreover, prominent plasma cells were observed, in addition to CD20+ B cells. Atypical cells with enlarged nuclei were present, and they were not hematopoietic but found as glial cells. JC virus (JCV) infection was verified with both immunohistochemistry and in situ hybridization; the final diagnosis was progressive multifocal leukoencephalopathy (PML). The patient was treated with mefloquine and discharged. This case is informative in understanding the host anti-viral response. Variable inflammatory cells were observed, including CD4+ and CD8+ T cells, plasma cells, and a small amount of perivascular CD20+ B cells. PD-1 and PD-L1 expression was observed in lymphoid cells and macrophages, respectively. PML with inflammatory reactions was thought fatal, and autopsy cases of PML with immune reconstitution inflammatory syndrome (IRIS) demonstrated excessive infiltration of only CD8+ T cells. However, this case revealed infiltration of variable inflammatory cells, and a favorable prognosis would be expected under PD-1/PD-L1 immune-checkpoint regulation.

Epidemiology of progressive multifocal leukoencephalopathy in Japan and effectiveness of mefloquine: A retrospective analysis of a nationwide inpatient database

INTRODUCTION

Progressive multifocal leukoencephalopathy (PML) is an infrequent yet devastating neurological infection that arises in immunocompromised patients. The epidemiological features of PML in Japan and its evolution in recent years remain unclear. There are no established treatments that directly target PML. Although mefloquine has shown in vitro activity against JC virus, its clinical effectiveness has not been confirmed in population-level studies.

METHODS

We retrospectively analyzed the admission data of patients with PML recorded in the Diagnosis Procedure Combination (DPC) database from fiscal year 2010 to 2020 (11 years). Descriptive statistics were used to illustrate the epidemiological features. Changes in the frequency of PML admission, underlying diseases, and in-hospital mortality over time were also examined. Furthermore, we evaluated the effectiveness of mefloquine in improving activities of daily living at discharge using propensity score matching.

RESULTS

We identified 610 PML cases diagnosed by the treating physicians, which may include possible PML. Among them, 419 were first-time admissions. The median age at admission was 62.0 years, and 62.8% were men. HIV was the most common underlying condition, accounting for 22.9% of cases, followed by hematologic malignancies (18.4%), and autoimmune diseases (17.9%). Over the study period, the frequency of PML admissions showed an increasing trend, whereas the in-hospital mortality rate showed a decreasing trend. The effectiveness of mefloquine was not confirmed.

CONCLUSIONS

The results of this study will help clarify and update the clinical picture of PML in Japan. The DPC database was shown to be useful tool for epidemiological research on rare infectious disease such as PML.

Cerebellar Progressive Multifocal Leukoencephalopathy Mimicking Anti-Yo-Antibody-Associated Rapidly Progressive Cerebellar Syndrome

A 58-year-old woman with a history of systemic lupus erythematosus (SLE) who was taking prednisolone and mycophenolate mofetil presented with gait disturbances that progressively worsened over a period of 3 months. Her blood test and cerebrospinal fluid (CSF) examination results did not indicate active SLE. Initial brain magnetic resonance imaging (MRI) revealed a small spotty lesion in the left cerebellar peduncle. The clinical course was consistent with rapidly progressive cerebellar syndrome (RPCS), which sometimes involves neuronal antibodies. The line blot assay detected anti-Yo antibodies, but no malignancy was found. Immunohistological techniques using rat brain sections yielded a negative result for anti-Yo antibodies. The second MRI revealed a focal lesion and surrounding spotty lesion in the left cerebellar peduncle, which was consistent with the punctate pattern observed in progressive multifocal leukoencephalopathy (PML). The CSF JCV-DNA test indicated the presence of cerebellar PML. Immunosuppressants were reduced, and mefloquine and mirtazapine were initiated. After approximately 2 years and 1 month, the CSF JCV-DNA results became negative. Cerebellar PML may exhibit a clinical course that is consistent with RPCS. The punctate pattern should be recognized as an early manifestation of PML. The CSF JCV-DNA copy number may serve as a useful indicator of PML stabilization.

Nationwide Laboratory Surveillance of Progressive Multifocal Leukoencephalopathy in Japan: Fiscal Years 2011-2020

Progressive multifocal leukoencephalopathy (PML) is a devastating demyelinating disease caused by JC virus (JCV), predominantly affecting patients with impaired cellular immunity. PML is a non-reportable disease with a few exceptions, making national surveillance difficult. In Japan, polymerase chain reaction (PCR) testing for JCV in the cerebrospinal fluid (CSF) is performed at the National Institute of Infectious Diseases to support PML diagnosis. To clarify the overall profile of PML in Japan, patient data provided at the time of CSF-JCV testing over 10 years (FY2011-2020) were analyzed. PCR testing for 1537 new suspected PML cases was conducted, and 288 (18.7%) patients tested positive for CSF-JCV. An analysis of the clinical information on all individuals tested revealed characteristics of PML cases, including the geographic distribution, age and sex patterns, and CSF-JCV-positivity rates among the study subjects for each type of underlying condition. During the last five years of the study period, a surveillance system utilizing ultrasensitive PCR testing and widespread clinical attention to PML led to the detection of CSF-JCV in the earlier stages of the disease. The results of this study will provide valuable information not only for PML diagnosis, but also for the treatment of PML-predisposing conditions.

Successful treatment of HIV-associated progressive multifocal leukoencephalopathy (PML) with mirtazapine, mefloquine, and IVIG combination therapy: a case report

Progressive multifocal leukoencephalopathy (PML) is a severe demyelinating disease of the central nervous system caused by reactivation of the polyomavirus JC (JCV). Human immunodeficiency virus (HIV) infection is one of the leading causes of PML which has high morbidity and mortality due to the lack of a proven standard treatment. We found clinical and radiological improvement with the combination of high-dose methylprednisolone, mirtazapine, mefloquine, and IVIG in our patient who presented with neurological symptoms and had diagnosed concurrent acquired immunodeficiency syndrome (AIDS) and PML. To our knowledge, our case is the first HIV-associated PML which responded to this combination therapy.

JC virus-induced progressive multifocal leukoencephalopathy in a presumably healthy patient

BACKGROUND

JC virus (JCV) is common among healthy individuals and remains latent but may be reactivated under immunosuppressive conditions, resulting in progressive multifocal leukoencephalopathy (PML). Here, we present a rare case of PML caused by JC virus infection in a previously healthy and immunocompetent patient.

CASE PRESENTATION

A 67-year-old female without any disease history was admitted after presenting with rapidly progressive dementia. The preoperative diagnosis was progressive multifocal leukoencephalopathy, and corticosteroid treatment did not improve the symptoms. Brain lesions were surgically sampled, and JCV infection was confirmed by high-throughput DNA gene detection. This patient received a combined treatment of mirtazapine, mefloquine, and traditional Chinese herbs, and had stabilization of the disease on followed-up.

CONCLUSIONS

Although it is a rare, this case demonstrates that JC virus infection within the brain occurs in apparently healthy people. This case may increase our understanding of virus infection when facing the coronavirus epidemic in recent years, considering that similar medications were used.

[The phenomenon of pseudotumorous cross immunohistochemical reactivity of glia in progressive multifocal leukoencephalopathy]

Progressive multifocal leukoencephalopathy (PML) is a subacute demyelinating brain damage caused by infection of oligodendrocytes and astrocytes with the lytic JC virus on the background of immunosuppression. A case report of PML with a tumor-like course is presented. Morphological diagnostics revealed non-specific staining of antibodies to Ki-67, p53, IDH1, NF and Vim in the nuclei of gliocytes affected by the JC virus. Histological examination and microscopic evaluation of the changes in the brain for the diagnosis of PML is a priority. The recommended intravital biopsy does not always help in clear verification of PML due to the limited volume of tissue fragments presented for research. For the correct interpretation of changes during an intravital pathological examination and verification of PML, it is important to take material during a stereotaxic biopsy, not only from the center, but from the edges and perifocal zone of the altered tissues for the possibility of a spatial histological assessment of the pathological process.

Progressive multifocal leukoencephalopathy successfully treated with mefloquine and literature review

Progressive multifocal leukoencephalopathy (PML) is an opportunistic infection due to reactivation of John Cunningham virus (JCV). The diagnosis depends on evidence from clinical, imaging, and virologic studies. When the cerebrospinal fluid shows a negative polymerase chain reaction result, brain biopsy is required to confirm the diagnosis. PML has no standard treatment except for immune reconstitution. The anti-JCV effect of mefloquine, however, is supported by some studies, and if brain biopsy is difficult, a mefloquine trial can be considered. We describe a case of possible PML successfully treated with mefloquine.

Infratentorial onset of progressive multifocal leukoencephalopathy in a patient with systematic lupus erythematosus complicated with lymphoma: a case report

Progressive multifocal leukoencephalopathy (PML) is a rare opportunistic infection of the central nervous system caused by reactivation of JC virus (JCV). Typical PML shows confluent, bilateral but asymmetric, subcortical lesions in the supratentorial white matter on magnetic resonance imaging (MRI). We report here a 50-year-old woman with systemic lupus erythematosus complicated with lymphoma who developed PML with atypical brain MRI findings limited to the infratentorial area at presentation. She presented with numbness on the right side of the face, including her tongue, clumsiness of the right hand, and gait disturbance, after completion of remission induction therapy for lymphoma, including rituximab. Brain MRI demonstrated a solitary lesion limited to the cerebellum and brainstem, but a definitive diagnosis could not be made from cerebrospinal fluid study or tentative histologic evaluation of brain biopsy specimens. Despite methylprednisolone pulse therapy, her neurological deficits progressively worsened. One month later, in-depth analysis of her cerebrospinal fluid and brain biopsy specimens confirmed the presence of JCV. Eventually, the localised unilateral crescent-shaped cerebellar lesions on MRI expanded to the contralateral cerebellum, middle cerebellar hemisphere, pons, and midbrain and finally developed multifocal invasion into the white matter of the cerebral hemispheres. Our case suggests that PML could first present with a solitary infratentorial lesion in immunocompromised patients.

Oleate-induced aggregation of LC3 at the trans-Golgi network is linked to a protein trafficking blockade

Oleate, the most abundant endogenous and dietary cis-unsaturated fatty acid, has the atypical property to cause the redistribution of microtubule-associated proteins 1A/1B light chain 3B (referred to as LC3) to the trans-Golgi network (TGN), as shown here. A genome-wide screen identified multiple, mostly Golgi transport-related genes specifically involved in the oleate-induced relocation of LC3 to the Golgi apparatus. Follow-up analyses revealed that oleate also caused the retention of secreted proteins in the TGN, as determined in two assays in which the secretion of proteins was synchronized, (i) an assay involving a thermosensitive vesicular stomatitis virus G (VSVG) protein that is retained in the endoplasmic reticulum (ER) until the temperature is lowered, and (ii) an isothermic assay involving the reversible retention of the protein of interest in the ER lumen and that was used both in vitro and in vivo. A pharmacological screen searching for agents that induce LC3 aggregation at the Golgi apparatus led to the identification of "oleate mimetics" that share the capacity to block conventional protein secretion. In conclusion, oleate represents a class of molecules that act on the Golgi apparatus to cause the recruitment of LC3 and to stall protein secretion.

Pharmacokinetic Profile of Oral Administration of Mefloquine to Clinically Normal Cats: A Preliminary In-Vivo Study of a Potential Treatment for Feline Infectious Peritonitis (FIP)

Simple Summary

In searching for antiviral agents against feline coronaviruses and feline caliciviruses, mefloquine, a human anti-malarial drug, has been demonstrated to reduce viral load of feline coronaviruses and feline calicivirus in infected cells. In this study, mefloquine was administered orally to seven clinically healthy cats twice weekly for four doses and mefloquine concentrations in blood were measured to investigate the pharmacokinetic profile—the movement of drug in the body. The maximum blood concentration of mefloquine was 2.71 ug/mL and was reached 15 h after a single oral dose was administered. Mefloquine side effects included vomiting following administration without food in some cats, and mild increases in symmetric dimethylarginine (SDMA), an early kidney biomarker. This study provides valuable information on mefloquine’s profile in cats as an introductory step towards investigating it as a potential treatment for feline coronavirus and feline calicivirus infection in cats.

Abstract

The pharmacokinetic profile of mefloquine was investigated as a preliminary study towards a potential treatment for feline coronavirus infections (such as feline infectious peritonitis) or feline calicivirus infections. Mefloquine was administered at 62.5 mg orally to seven clinically healthy cats twice weekly for four doses and mefloquine plasma concentrations over 336 h were measured using high pressure liquid chromatography (HPLC). The peak plasma concentration (Cmax) after a single oral dose of mefloquine was 2.71 ug/mL and time to reach Cmax (Tmax) was 15 h. The elimination half-life was 224 h. The plasma concentration reached a higher level at 4.06 ug/mL when mefloquine was administered with food. Adverse effects of dosing included vomiting following administration without food in some cats. Mild increases in serum symmetric dimethylarginine (SDMA), but not creatinine, concentrations were observed. Mefloquine may provide a safe effective treatment for feline coronavirus and feline calicivirus infections in cats.