Progressive Multifocal Leukoencephalopathy: Recent Advances and a Neuro-Ophthalmological Review

Approach to Neurologic Complications in the Immunocompromised Patient

Neurologic complications are common in immunocompromised patients, including those with advanced human immunodeficiency virus, transplant recipients, and patients on immunomodulatory medications. In addition to the standard differential diagnosis, specific pathogens and other conditions unique to the immunocompromised state should be considered in the evaluation of neurologic complaints in this patient population. A thorough understanding of these considerations is critical to the inpatient neurologist in contemporary practice, as increasing numbers of patients are exposed to immunomodulatory therapies. In this review, we provide a chief complaint-based approach to the clinical presentations and diagnosis of both infectious and noninfectious complications particular to immunocompromised patients.

Neurologic Infections in Patients on Immunomodulatory and Immunosuppressive Therapies

PURPOSE OF REVIEW

Both broadly immunosuppressive medications and selective immunomodulatory agents that act on particular components of the immune system are increasingly used in the treatment of neurologic and non-neurologic diseases. These therapies predispose patients to particular infections, some of which may affect the nervous system. Therefore, familiarity with the clinical and radiologic features of neurologic infections associated with specific immunomodulatory therapies is of importance for the practicing neurologist. This article reviews these neuroinfectious conditions, as well as other neurologic complications unique to transplant recipients and other patients who are immunocompromised.

RECENT FINDINGS

Diagnosis of infectious pathogens in patients who are immunocompromised may be particularly challenging because a decreased immune response can lead to atypical imaging or laboratory findings. Next-generation sequencing and other novel diagnostic modalities may improve the rate of early identification of neurologic infections in patients who are immunocompromised and ultimately ameliorate outcomes in this vulnerable population.

SUMMARY

A broad range of bacterial, viral, fungal, and parasitic infections of the nervous system can complicate solid organ and hematopoietic cell transplantation as well as other forms of immunocompromise. In addition to neurologic infections, such patients are at risk of neurotoxic and neuroinflammatory complications related to immunomodulatory and immunosuppressive therapies. Early recognition of infectious and noninfectious complications of immunocompromise is essential to guide appropriate treatment, which can include antimicrobial therapy and, in some cases, withdrawal of the predisposing medication with a transition to an alternative regimen.

A comparative study of multimodal magnetic resonance in the differential diagnosis of acquired immune deficiency syndrome related primary central nervous system lymphoma and infection

Background

Patients with acquired immune deficiency syndrome (AIDS) often suffer from opportunistic infections and related primary central nervous system lymphoma (AR-PCNSL). Both diseases showed multiple ring enhancement lesions in conventional magnetic resonance (MR). It is very difficult to make the differential diagnosis. We aimed to investigate whether multimodal MR (diffusion weighted imaging (DWI)/ apparent diffusion coefficient (ADC), 3D pseudo-continuous arterial spin labeling (3D-pCASL) and susceptibility-weighted imaging (SWI)) combined with conventional MR can differentiate AR-PCNSL from infections.

Methods

This was a prospective study. We recruited 19 AIDS patients who were divided into AR-PCNSL group (9 cases) and infection group (10 cases) by pathological results. We analyzed whether there was statistical (Fisher’s method) difference in multimodal MR between the two groups. We analyzed whether multimodal MR combined with conventional MR could improve the diagnosis of AR-PCNSL.

Results

The lesions were more likely involved the paraventricular (0.020) and corpus callosum (0.033) in AR-PCNSL group in conventional MR. In multimodal MR, AR-PCNSL group showed low ADC value, with p values of 0.001. Infection group more inclined to high ADC value, with p was 0.003. In multimodal MR, AR-PCNSL group had more low signal intensity (grade 2–3) in the degree of intratumoral susceptibility signal intensity in SWI (SWI-ITSS), with p values of 0.001. The sensitivity, specificity of conventional MR in the diagnosis of AR-PCNSL was 88.9 and 70.0%. The conventional MR sequence combined with DWI/ADC sequence in the diagnosis of AR-PCNSL had a sensitivity of 100.0%, and a specificity of 60.0%. The sensitivity and specificity of the conventional MR sequence combined with the SWI-ITSS sequence in the diagnosis of AR-PCNSL were 100 and 70.0%. The conventional MR combined with ADC or SWI-ITSS improved the diagnosis of AR-PCNSL.

Conclusion

Multimodal MR could distinguish AR-PCNSL from infectious lesions. The multimodal MR (DWI/ADC or SWI-ITSS) combined with conventional MR could improve the diagnosis of AR-PCNSL. The ADC value should be attached importance in clinical work. When distinguishing AR-PCNSL from toxoplasmosis or tuberculoma, SWI should be used to obtain a correct diagnosis.

Progressive multifocal leukoencephalopathy in a patient with occult hypogammaglobulinemia experiencing bilateral visual impairment

INTRODUCTION

Progressive multifocal leukoencephalopathy (PML) is a rare, lethal, demyelinating disease classically seen in profoundly immunosuppressed individuals. It is caused by intracerebral infection by John Cunningham polyomavirus (JCV). We report a rare case of PML in a man with presumed immunocompetence at presentation experiencing bilateral painless visual impairment.

CASE DESCRIPTION

A 60-year-old man with a 3-week history of bilateral painless visual impairment attended our ophthalmology department. Unusually, he navigated around the room well and was able to read 4 of 13 Ishihara test plates in spite of a best-corrected visual acuity of counting fingers at 1 m bilaterally. Slit lamp examination, routine blood tests and optical coherence tomography (OCT) of the maculae and discs were unremarkable. Diffuse hyperintense white matter lesions on T2-weighted magnetic resonance imaging of the brain and detection of JCV within the parietal lobe tissue obtained by biopsy confirmed PML. Additional investigations identified an underlying hypogammaglobulinaemia, which may have initiated PML. He received intravenous immunoglobulin but passed away 2 months after diagnosis.

CONCLUSIONS

To our knowledge this case is one of only a handful worldwide to describe PML developing in a patient with presumed immunocompetence at presentation - there was no previous history of recurrent, chronic, or atypical infections. There has only been one other report of visual symptoms presenting as the primary complaint. The case illustrates the importance of ruling out organic, central nervous system pathology in patients presenting with visual loss and normal objective visual function tests such as slit lamp examination and OCT.

Multiple sclerosis in ophthalmology: beyond optic neuritis

Disorders of the visual system are one of the main features of multiple sclerosis (MS), and have a great impact on the quality of life of patients. Although optic neuritis is the most frequent manifestation, there are other ophthalmological processes not related to neuritis, a knowledge of which is very useful in the management of patients with MS. These abnormalities are described, grouped into impairments of the afferent pathway, efferent pathway, or upper cerebral areas. Additionally, the main ophthalmological side effects of the drugs currently used in the control of MS are described.

Progressive multifocal leukoencephalopathy during ixazomib-based chemotherapy

Progressive multifocal leukoencephalopathy (pml) is a rare demyelinating disease of the central nervous system that most often affects immunocompromised individuals. It is caused by the reactivation of the John Cunningham virus (jcv), which is found in latent form in the majority of adults. We describe a 59-year-old man with multiple myeloma who developed severe neurological deficits during treatment with ixazomib-based chemotherapy. A diagnosis of pml was established with gadolinium-enhanced magnetic resonance imaging (mri) and by detection of jcv in the cerebrospinal fluid. Despite cessation of chemotherapy and treatment with mirtazapine, he had an inexorable neurological decline and died two months after presenting to hospital. Multiple myeloma and its treatments can predispose patients to opportunistic infections including pml. Although there have been case reports of pml in patients with multiple myeloma treated with bortezomib (a different proteosome inhibitor), this is, to our knowledge, the first documented case of pml in a patient treated with a regimen that includes ixazomib.

Long-term safety evaluation of natalizumab for the treatment of multiple sclerosis

INTRODUCTION

Natalizumab is a humanized monoclonal antibody highly effective in relapsing-remitting multiple sclerosis (MS). Important concerns about its safety have been pointed out mainly because of the risk of progressive multifocal leukoencephalopathy (PML), caused by the opportunistic John-Cunningham virus (JCV). Areas covered: This review analyzes all the safety aspects related to the use and safety of natalizumab in MS patients. Other than PML, post-marketing, safety red-flags have been reported, as liver or haematological serious adverse events. Pregnancy evidences will be pointed out. The risk of PML depends on: concomitant or previous immunosuppression, exposure duration, anti-JCV antibody level. In natalizumab-related PML the average survival is 77%; prognostic features and information for the earliest identification of PML have been identified to maximally reduce its incidence, mortality and morbidity. Expert opinion: Natalizumab is a highly effective drug for MS patients but its safety issues represent a relevant limitation and impose strict clinical surveillance of treated patients. Some post-marketing safety red-flags have been pointed out, with higher attention to severe liver failures and limphoma cases. If PML and its consequences are considered the most relevant issues, a continuous surveillance must be maintained also regarding other possible SAEs like liver diseases and malignancies.

Visual consequences of medications for multiple sclerosis: the good, the bad, the ugly, and the unknown

Multiple sclerosis (MS) is associated with vision changes both due to MS effects on visual pathways and due to medication effects on the visual pathways. Distinguishing the causes of vision change are critical to appropriate diagnosis and management. The incidence, presentation, and treatment of fingolimod-associated macular edema, alemtuzumab-associated thyroid orbitopathy, and progressive multifocal leukoencephalopathy in MS patients are reviewed. Evidence for beneficial effects of acute, chronic, and symptomatic MS medications on vision is presented.

Keeping it in check: chronic viral infection and antiviral immunity in the brain

It is becoming clear that the manner by which the immune response resolves or contains infection by a pathogen varies according to the tissue that is affected. Unlike many peripheral cell types, CNS neurons are generally non-renewable. Thus, the cytolytic and inflammatory strategies that are effective in controlling infections in the periphery could be damaging if deployed in the CNS. Perhaps for this reason, the immune response to some CNS viral infections favours maintenance of neuronal integrity and non-neurolytic viral control. This modified immune response - when combined with the unique anatomy and physiology of the CNS - provides an ideal environment for the maintenance of viral genomes, including those of RNA viruses. Therefore, it is possible that such viruses can reactivate long after initial viral exposure, contributing to CNS disease.

Progressive Multifocal Leukoencephalopathy in HIV-Uninfected Individuals

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system (CNS) caused by the human neurotropic polyomavirus JC (JCV). The disease occurs virtually exclusively in immunocompromised individuals, and, prior to the introduction of antiretroviral therapy, was seen most commonly in the setting of HIV/AIDS. More recently, however, the incidence of PML in HIV-uninfected persons has increased with broader use of immunosuppressive and immunomodulatory medications utilized in a variety of systemic and neurologic autoimmune disorders. In this review, we discuss the epidemiology and clinical characteristics of PML in HIV-uninfected individuals, as well as diagnostic modalities and the limited treatment options. Moreover, we describe recent findings regarding the neuropathogenesis of PML, with specific focus on the unique association between PML and natalizumab, a monoclonal antibody that prevents trafficking of activated leukocytes into the CNS that is used for the treatment of multiple sclerosis.

Neurobehavioral Manifestations of Human Immunodeficiency Virus/AIDS: Diagnosis and Treatment

Behavioral disorders are common in persons infected with human immunodeficiency virus (HIV). The differential includes preexisting psychiatric diseases, substance abuse, direct effects of HIV infection, opportunistic infection, and the adverse effects of medical therapies. Many patients have more than one contributing or comorbid problem to explain these behavioral changes. The differential should always include consideration of psychosocial, genetic, and medical causes of disease. Treatment strategies must take into account the coadministration of antiretroviral therapy and the specific neurologic problems common in patients infected with HIV.

Progressive Multifocal Leukoencephalopathy with Negative JC Virus PCR following Treatment of Follicular Lymphoma: Implications for Biologics in the Era of Targeted Cancer Therapy

Anticancer therapy predisposes patients to infections by the immunosuppression that results from treatment. Although 85% of patients with progressive multifocal leukoencephalopathy (PML) have concurrent HIV/AIDS, PML can also develop in patients after they receive chemotherapy for cancer. The case herein describes a 69-year-old man with history of follicular lymphoma who presented with progressive dysarthria and right-sided paralysis. He received rituximab one year prior to presentation. PET scan suggested no recurrence of lymphoma. Cerebrospinal fluid (CSF) analysis was negative and showed fewer than 500 copies/mL of JC virus. However, brain biopsy showed chromatin margination and viropathic change within oligodendrocytes, confirming PML. He was started on mirtazapine and mefloquine with some clinical improvement. To our knowledge, this is the first case of rituximab-associated PML in a patient with negative JC virus PCR from the CSF. Recognition of PML in the differential of oncology patients with CNS symptoms is an important consideration as we enter the era of targeted therapy and personalized cancer medicine involving biologics. Furthermore, screening of patients for presence of subclinical JC viremia prior to the use of biologics may be an important component of assessing patient candidacy for these agents.

Progressive Multifocal Leukoencephalopathy

Progressive multifocal leukoencephalopathy (PML) is a devastating demyelinating disease with significant morbidity and mortality and no effective, targeted therapies. It is most often observed in association with abnormalities of cell-mediated immunity, in particular human immunodeficiency virus (HIV) infection, but also occurs in association with lymphoproliferative diseases, certain immunosuppressive and immunomodulatory regimens, and other conditions. The etiologic agent of PML is a small, ubiquitous polyomavirus, the JC virus (JCV, also known as JCPyV), for which at least 50% of the adult general population is seropositive. PML results when JCV replicates within cerebral oligodendrocytes and astrocytes, leading to oligodendrocyte death and demyelination. Unfortunately, no treatments have been convincingly demonstrated to be effective, though some have been employed in desperation; treatment otherwise includes attempts to restore any immune system defect, such as the withdrawal of the causative agent if possible, and general supportive care.