Lessons learned from fatal progressive multifocal leukoencephalopathy in a patient with multiple sclerosis treated with natalizumab

Recruitment and Residence of Intestinal T Cells - Lessons for Therapy in Inflammatory Bowel Disease

Targeting leukocyte trafficking in the management of inflammatory bowel disease [IBD] has been a significant therapeutic advance over the past 15 years. However, as with other advanced therapies, phase III clinical trials report response to trafficking inhibitors in only a proportion of patients, with fewer achieving clinical remission or mucosal healing. Additionally, there have been significant side effects, most notably progressive multifocal leukoencephalopathy in association with the α4 inhibitor natalizumab. This article reviews the mechanisms underpinning T cell recruitment and residence, to provide a background from which the strength and limitations of agents that disrupt leukocyte trafficking can be further explored. The therapeutic impact of trafficking inhibitors is underpinned by the complexity and plasticity of the intestinal immune response. Pathways essential for gut homing in health may be bypassed in the inflamed gut, thus providing alternative routes of entry when conventional homing molecules are targeted. Furthermore, there is conservation of trafficking architecture between proinflammatory and regulatory T cells. The persistence of resident memory cells within the gut gives rise to local established pro-inflammatory populations, uninfluenced by inhibition of trafficking. Finally, trafficking inhibitors may give rise to effects beyond the intended response, such as the impact of vedolizumab on innate immunity, as well as on target side effects. With significant research efforts into predictive biomarkers already underway, it is ultimately hoped that a better understanding of trafficking and residence will help us predict which patients are most likely to respond to inhibition of leukocyte trafficking, and how best to combine therapies.

Epidemiology of Ocular Manifestations in Autoimmune Disease

The global prevalence of autoimmune diseases is increasing. As a result, ocular complications, ranging from minor symptoms to sight-threatening scenarios, associated with autoimmune diseases have also risen. These ocular manifestations can result from the disease itself or treatments used to combat the primary autoimmune disease. This review provides detailed insights into the epidemiological factors affecting the increasing prevalence of ocular complications associated with several autoimmune disorders.

Ocular adverse events from pharmacological treatment in patients with multiple sclerosis-A systematic review of the literature

PURPOSE

The aim of this study was to review the scientific evidence and describe the ocular treatment-emergent adverse events (TEAEs) related to pharmacological treatment in patients with multiple sclerosis.

METHODS

A systematic review of literature was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines in the MEDLINE, LILACS, EMBASE, and COCHRANE databases. Articles were filtered based on title and abstract considering the selection criteria and subsequently filtered by full-text reading. The resulting articles were evaluated using the Joanna Briggs Institute Quality Tools. Study characteristics and results were extracted and presented in structured tables to conduct a narrative synthesis.

RESULTS

A total of 2852 published articles were extracted using our strategy. After removing duplicates, 2841 articles were screened based on title and abstract, 102 articles were evaluated using quality tools, and 69 articles were filtered by full-text reading. Through this search strategy, 60 articles met all the inclusion criteria and seven articles, through a search update conducted in the same manner, were included. This resulted in 67 articles meeting the inclusion criteria, of which 11 were experimental and 56 were observational. The therapies related to ocular TEAEs were alemtuzumab, amantadine, fingolimod, steroids, CTLA-4 Ig, estriol, interferon β, natalizumab, hyperbaric oxygen, rituximab, siponimod, teriflunomide, and tovaxin. Fingolimod and siponimod were commonly associated with macular edema, interferon β was associated with retinopathy, alemtuzumab was associated with thyroid eye disease, amantadine was associated with corneal edema, and steroids were associated with acute retinal necrosis. Opportunistic infections were also found, and there was one life-threatening case.

CONCLUSIONS

Our search revealed different methodological assessments of the topic. However, longitudinal studies regarding ocular TEAEs related to multiple sclerosis therapy are necessary to provide evidence-based recommendations, especially in understudied regions such as Latin America and Africa. Physicians should monitor ocular symptoms in patients being treated for multiple sclerosis and consider an interdisciplinary approach.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO ID CRD42020106886.

Progressive Multifocal Leukoencephalopathy in the Absence of Typical Radiological Changes: Can We Make a Diagnosis?

Patient: Female, 32

Final Diagnosis: Progressive multifocal leukoencephalopathy

Symptoms: Progressive behavioral changes • seizures

Medication: —

Clinical Procedure: Management

Specialty: Neurology

HIV-associated opportunistic CNS infections: pathophysiology, diagnosis and treatment

Nearly 30 years after the advent of antiretroviral therapy (ART), CNS opportunistic infections remain a major cause of morbidity and mortality in HIV-positive individuals. Unknown HIV-positive disease status, antiretroviral drug resistance, poor drug compliance, and recreational drug abuse are factors that continue to influence the morbidity and mortality of infections. The clinical and radiographic pattern of CNS opportunistic infections is unique in the setting of HIV infection: opportunistic infections in HIV-positive patients often have characteristic clinical and radiological presentations that can differ from the presentation of opportunistic infections in immunocompetent patients and are often sufficient to establish the diagnosis. ART in the setting of these opportunistic infections can lead to a paradoxical worsening caused by an immune reconstitution inflammatory syndrome (IRIS). In this Review, we discuss several of the most common CNS opportunistic infections: cerebral toxoplasmosis, progressive multifocal leukoencephalopathy (PML), tuberculous meningitis, cryptococcal meningitis and cytomegalovirus infection, with an emphasis on clinical pearls, pathological findings, MRI findings and treatment. Moreover, we discuss the risk factors, pathophysiology and management of IRIS. We also summarize the challenges that remain in management of CNS opportunistic infections, which includes the lack of phase II and III clinical trials, absence of antimicrobials for infections such as PML, and controversy regarding the use of corticosteroids for treatment of IRIS.

Antibody blockade of CLEC12A delays EAE onset and attenuates disease severity by impairing myeloid cell CNS infiltration and restoring positive immunity

The mechanism of dendritic cells (DCs) recruitment across the blood brain barrier (BBB) during neuroinflammation has been the least explored amongst all leukocytes. For cells of myeloid origin, while integrins function at the level of adhesion, the importance of lectins remains unknown. Here, we identified functions of one C-type lectin receptor, CLEC12A, in facilitating DC binding and transmigration across the BBB in response to CCL2 chemotaxis. To test function of CLEC12A in an animal model of multiple sclerosis (MS), we administered blocking antibody to CLEC12A that significantly ameliorated disease scores in MOG_35–55-induced progressive, as well as PLP_138–151-induced relapsing-remitting experimental autoimmune encephalomyelitis (EAE) mice. The decline in both progression and relapse of EAE occurred as a result of reduced demyelination and myeloid cell infiltration into the CNS tissue. DC numbers were restored in the spleen of C57BL/6 and peripheral blood of SJL/J mice along with a decreased TH17 phenotype within CD4⁺ T-cells. The effects of CLEC12A blocking were further validated using CLEC12A knockout (KO) animals wherein EAE disease induction was delayed and reduced disease severity was observed. These studies reveal the utility of a DC-specific mechanism in designing new therapeutics for MS.

The Ocular Manifestations of Drugs Used to Treat Multiple Sclerosis

Recent times have seen an increase in the number of options to treat multiple sclerosis. Ocular manifestations of multiple sclerosis are well known to treating physicians; however, the medications used to treat multiple sclerosis can also have ocular side effects. This review article focuses on the ocular manifestations of corticosteroids and disease-modifying agents such as interferon, fingolomod, natalizumab, alemtuzumab and mitoxantron used to treat the disease. The ocular manifestations of multiple sclerosis treatments can be varied depending on the drug used, and include retinopathy, chronic central serous chorioretinopathy, macular oedema, Graves' ophthalmopathy and cortical blindness. These effects may be specific to the drug or secondary to their immunosuppressive effect. The association of macular oedema with fingolomod is clear and merits ocular screening for toxicity. The immunosuppressive nature of the treatments makes patients prone to acquired infections. Hence, if a patient with multiple sclerosis presents with vision loss, infectious and drug-induced aetiology should be considered alongside relapses of multiple sclerosis itself as a cause.

FLAIRfusion Processing with Contrast Inversion : Improving Detection and Reading Time of New Cerebral MS Lesions

PURPOSE

To evaluate the performance of an innovative image processing approach for detection of T2-weighted hyperintense multiple sclerosis (MS) lesions.

METHODS

In this study 20 consecutive patients with inflammatory demyelinating lesions were retrospectively evaluated of whom 10 patients featured progressive disease and 10 a stable lesion load. 3 mm transversal FLAIRfusion imaging was processed and archived. Image processing was performed through landmark-based 3D co-registration of the previous and current isotropic FLAIR examination followed by inversion of image contrast. Thereby, the hyperintense signals of the unchanged MS plaques extinguish each other, while newly developed lesions appear bright on FLAIRfusion. Diagnostic performance was evaluated by 4 experienced readers. Consensus reading supplied the reference standard. Sensitivity, specificity, NPV (negative predictive value), PPV (positive predictive value), interreader agreement and reading time were the outcome measures analyzed.

RESULTS

Combined sensitivity was 100% at a specificity of 88.2%, with PPV ranging from 83.3% to 90.1% and NPV at 100%. Reading time was nearly 5‑fold faster than conventional side by side comparison (35.6 s vs. 163.7 s, p < 0.001). Cohen's kappa was excellent (>0.75; p < 0.001) and Cronbach's alpha was 0.994.

CONCLUSION

FLAIRfusion provides reliable detection of newly developed MS lesions along with strong interreader agreement across all levels of expertise in 35 s of reading time.

Myelin phagocytosis by astrocytes after myelin damage promotes lesion pathology

Astrocytes are key players in the pathology of multiple sclerosis and can assume beneficial and detrimental roles during lesion development. The triggers and timing of the different astroglial responses in acute lesions remain unclear. Astrocytes in acute multiple sclerosis lesions have been shown previously to contain myelin debris, although its significance has not been examined. We hypothesized that myelin phagocytosis by astrocytes is an early event during lesion formation and leads to astroglial immune responses. We examined multiple sclerosis lesions and other central nervous system pathologies with prominent myelin injury, namely, progressive multifocal leukoencephalopathy, metachromatic leukodystrophy and subacute infarct. In all conditions, we found that myelin debris was present in most astrocytes at sites of acute myelin breakdown, indicating that astroglial myelin phagocytosis is an early and prominent feature. Functionally, myelin debris was taken up by astrocytes through receptor-mediated endocytosis and resulted in astroglial NF-κB activation and secretion of chemokines. These in vitro results in rats were validated in human disease where myelin-positive hypertrophic astrocytes showed increased nuclear localization of NF-κB and elevated chemokine expression compared to myelin-negative, reactive astrocytes. Thus, our data suggest that myelin uptake is an early response of astrocytes in diseases with prominent myelin injury that results in recruitment of immune cells. This first line response of astrocytes to myelin injury may exert beneficial or detrimental effects on the lesion pathology, depending on the inflammatory context. Modulating this response might be of therapeutic relevance in multiple sclerosis and other demyelinating conditions.

Natalizumab-Related Progressive Multifocal Leukoencephalopathy in Multiple Sclerosis: Findings from an Italian Independent Registry

Background

The monoclonal antibody natalizumab (NTZ) is a highly effective treatment for patients with multiple sclerosis (MS). However, this drug is associated with increased risk of developing Progressive Multifocal Leukoencephalopathy (PML), an opportunistic infection of central nervous system (CNS) caused by the John Cunningham polyomavirus (JCV).

Objective

To describe the 12-month clinical course of 39 patients with MS (28 women, 11 men) who developed NTZ-related PML after a mean exposure of 39 infusions.

Methods

An Italian independent collaborative repository initiative collected and analyzed socio-demographic, clinical, magnetic resonance imaging (MRI) data and number of JCV-DNA copies detected on cerebrospinal fluid (CSF) samples of patients diagnosed as affected by NTZ-related PML. The evolution of disability, measured by the Expanded Disability Status Scale, was assessed at NTZ start, at PML diagnosis and after 2, 6 and 12 months from PML diagnosis. The effect of clinical and paraclinical characteristics at PML diagnosis on the final outcome was also investigated.

Results

Ten patients (25.6%) were diagnosed before 24 NTZ infusions. In six cases (15.4%) the PML suspect was made on the basis of highly suggestive MRI findings in absence of any detectable change of clinical conditions (asymptomatic PML). In patients with symptomatic PML, the diagnosis was quicker for those who presented with cognitive symptoms (n = 12) rather than for those with other neurological pictures (n = 21) (p = 0.003). Three patients (7.7%) died during the 12-month observation period, resulting in a survival rate of 92.3%. Asymptomatic PML, more localized brain involvement and gadolinium-enhancement detected at MRI, as well as lower viral load were associated with a better disability outcome (p-values<0.01).

Conclusion

Our findings support that early PML diagnosis, limited CNS involvement and initial signs of immune restoration are associated with a better outcome and higher survival rate, and confirm the utility of MRI as a surveillance tool for NTZ-treated patients.

Drug-associated progressive multifocal leukoencephalopathy: a clinical, radiological, and cerebrospinal fluid analysis of 326 cases

The implementation of a variety of immunosuppressive therapies has made drug-associated progressive multifocal leukoencephalopathy (PML) an increasingly prevalent clinical entity. The purpose of this study was to investigate its diagnostic characteristics and to determine whether differences herein exist between the multiple sclerosis (MS), neoplasm, post-transplantation, and autoimmune disease subgroups. Reports of possible, probable, and definite PML according to the current diagnostic criteria were obtained by a systematic search of PubMed and the Dutch pharmacovigilance database. Demographic, epidemiologic, clinical, radiological, cerebrospinal fluid (CSF), and histopathological features were extracted from each report and differences were compared between the disease categories. In the 326 identified reports, PML onset occurred on average 29.5 months after drug introduction, varying from 14.2 to 37.8 months in the neoplasm and MS subgroups, respectively. The most common overall symptoms were motor weakness (48.6 %), cognitive deficits (43.2 %), dysarthria (26.3 %), and ataxia (24.1 %). The former two also constituted the most prevalent manifestations in each subgroup. Lesions were more often localized supratentorially (87.7 %) than infratentorially (27.4 %), especially in the frontal (64.1 %) and parietal lobes (46.6 %), and revealed enhancement in 27.6 % of cases, particularly in the MS (42.9 %) subgroup. Positive JC virus results in the first CSF sample were obtained in 63.5 %, while conversion after one or more negative outcomes occurred in 13.7 % of cases. 52.2 % of patients died, ranging from 12.0 to 83.3 % in the MS and neoplasm subgroups, respectively. In conclusion, despite the heterogeneous nature of the underlying diseases, motor weakness and cognitive changes were the two most common manifestations of drug-associated PML in all subgroups. The frontal and parietal lobes invariably constituted the predilection sites of drug-related PML lesions.

Simian Virus 40 Infection in the Spinal Cord of Simian Immunodeficiency Virus-Immunosuppressed Rhesus Macaques

Progressive multifocal leukoencephalopathy (PML) is an often-fatal demyelinating disease of the CNS that usually develops in immunocompromised individuals because of reactivation of quiescent JC virus (JCV). There are only a few reports of JCV infection in the human spinal cord. Progressive multifocal leukoencephalopathy-like demyelinating lesions have been documented in the brains of simian immunodeficiency virus-infected macaques. To determine whether simian virus 40 (SV40) can infect and cause PML lesions in spinal cords of immunosuppressed macaques, we examined archival spinal cord samples from 15 simian immunodeficiency virus-infected rhesus monkeys with acquired immunodeficiency syndrome and SV40 infection of the brain. Among those, 6 (40%) had SV40-infected cells in the spinal cord, including 1 with PML-like lesions, 1 with PML-like lesions and meningoencephalitis, 2 with meningoencephalitis, 1 with gray matter gliosis, and 1 with no lesions. One animal with a large PML-like lesion had extensive demyelination and SV40 infection of astrocytes, oligodendrocytes, and meningeal cells. None of the 6 animals had SV40-infected spinal cord neurons. These observations indicate that, like JCV in immunosuppressed humans, SV40 can infect glial cells and cause PML-like lesions in the spinal cord of immunosuppressed rhesus macaques. Rhesus macaques could serve as an animal model to study polyomavirus infection and pathogenesis in the spinal cord.

Non-Hodgkin Lymphoma of the Stomach in a Patient Treated with Natalizumab

A 61-year-old man with relapsing-remitting multiple sclerosis developed extranodal large B-cell lymphoma of the stomach following monthly natalizumab infusions for 6 years. Development of lymphoproliferative disorders increases with chronic use of immunosuppression. Cases of primary central nervous system lymphoma as well as one case of peripheral T-cell lymphoma have previously been reported with natalizumab use. Given the absence of a known association between multiple sclerosis and extranodal presentations of diffuse large B-cell lymphoma, a causal association with natalizumab administration cannot be excluded.

Patients characteristics influencing the longitudinal utilization of steroids in multiple sclerosis--an observational study

BACKGROUND

Multiple Sclerosis is the most common disease in young adults affecting the central nervous system. Disease may progress with acute attacks (relapsing MS) or continuously (progressive MS). Glucocorticosteroids are used in the treatment of acute attacks. The aim of this study was to analyse characteristics of patients with MS, and their influence on current treatment patterns of relapses with glucocorticosteroids.

DESIGN

In 2001, the German National MS Society initiated the German MS-Registry. Patients with relapsing MS were included (n = 5106) from this registry. Logistic regression models were used to detect trends over time. The likelihood of administration of steroids is modelled in dependence of calendar year and in dependence to confounders in treatment conditions. The sample size allows that odds ratios can be detected with a power of 90% (alpha = 0.05).

RESULTS

Administration of glucocorticosteroids was influenced by EDSS (P < 0.0001), age (P < 0.0001) and disease duration (P < 0.0001). Therapy administration in an outpatient setting was more likely in patients with higher EDSS (P < 0.0001) and longer disease duration (P < 0.0001). The utilization of glucocorticosteroids increased with higher EDSS for all relapsing patients. Interestingly, all overutilization of glucocorticosteroids decreased over time and was accompanied by a steadily increased administration of emergent therapeutics. Although there are about 70% of registered patients with relapsing MS on immune-modulatory treatment, almost 60% of them received glucocorticosteroids for treatment of relapses.

CONCLUSIONS

Treatment patterns with glucocorticosteroids in patients with MS are influenced mainly by EDSS and disease duration. The decline in the utilization of glucocorticosteroids is accompanied by an increase in natalizumab treatment.

Natalizumab: risk stratification of individual patients with multiple sclerosis

At present, three risk factors for the development of progressive multifocal leukoencephalopathy (PML) in natalizumab-treated patients have been identified: the presence of antibodies against JC virus (JCV); the duration of natalizumab treatment, especially if longer than 2 years; and the use of immunosuppressants prior to receiving natalizumab. The most commonly used strategy to assess the individual PML risk includes serum anti-JCV antibody testing. Based on the knowledge on all known risk factors, an algorithm for PML risk stratification has been proposed, where patients with the highest PML risk are those with positive anti-JCV antibodies, treatment duration longer than 2 years, with or without prior history of immunosuppression. These patients would have an approximate incidence of PML of 11.1 (with prior immunosuppression) or 4.6 (without prior immunosuppression) cases per 1,000 patients treated with natalizumab (and treatment duration longer than 2 years). In this review, new data on PML risk factors and possible new strategies for PML risk stratification are discussed.

The chameleon of neuroinflammation: magnetic resonance imaging characteristics of natalizumab-associated progressive multifocal leukoencephalopathy

Natalizumab is a monoclonal antibody against α4-integrin approved for the treatment of multiple sclerosis (MS) due to a positive effect on clinical and magnetic resonance imaging (MRI) outcome measures. However, one relatively rare but serious side effect of this drug is a higher risk of developing progressive multifocal leukoencephalopathy (PML). Since the FDA approval, more than 300 natalizumab-associated PML cases have been documented among more than 100,000 treated MS patients. MRI is a crucial tool in the surveillance of patients treated with natalizumab in order to detect possible signs of PML in the asymptomatic stage. Although classical imaging characteristics of PML are well established, MRI findings in natalizumab-associated PML, particularly in early disease stages, show rather new and heterogeneous imaging findings including different patterns of inflammation with contrast enhancement. This review provides a comprehensive overview of the heterogeneous imaging findings in natalizumab-associated PML in the context of the underlying pathophysiology, histopathology, and the diagnostic procedure. We describe the MRI patterns of PML lesion evolution and complications including immune reconstitution inflammatory syndrome (IRIS). Finally, we present guidelines to differentiate MRI findings in PML from inflammatory demyelinating lesions, to facilitate the early diagnosis of PML in patients treated with natalizumab.