Prophylactic antiepileptic treatment reduces seizure frequency in natalizumab-associated progressive multifocal leukoencephalopathy

Course of neuropsychological impairment during natalizumab-associated progressive multifocal leukoencephalopathy

BACKGROUND AND PURPOSE

Progressive multifocal leukoencephalopathy (PML), an opportunistic infection of the central nervous system from the John Cunningham virus (JCV), is a side effect of natalizumab (NTZ) treatment for relapsing-remitting multiple sclerosis (RRMS), potentially leading to a substantial increase of physical and mental disability. Nevertheless, data of neuropsychological impairment during the NTZ-PML disease course are missing. Our objective was to evaluate the neuropsychological disease course of NTZ-PML patients and to compare neuropsychological deficits of NTZ-PML patients with two different non-PML multiple sclerosis (MS) cohorts.

METHODS

Neuropsychological examinations of 28 NTZ-PML patients performed during different phases of the disease ([i] at PML diagnosis, [ii] during immune reconstitution inflammatory syndrome [IRIS], and [iii] post-IRIS/PML) were retrospectively analyzed and compared to those of NTZ-treated RRMS or secondary progressive MS patients with and without immunotherapy.

RESULTS

Compared to controls, NTZ-PML patients performed worse in neuropsychological examinations during all stages of disease, mainly affecting visuospatial ability and working memory. Furthermore, failure to eliminate the JCV from the central nervous system was associated with a progredient decline of cognition, especially working memory.

CONCLUSIONS

Working memory and visuospatial abilities are the core neuropsychological deficits of NTZ-PML patients in long-term follow-up. Our findings should be implemented in neurorehabilitation strategies.

Management of seizures in patients with multiple sclerosis; an Iranian consensus

PURPOSE

Cooccurrence of a seizure in a patient with multiple sclerosis (MS) may complicate the management process. Questions, which may complicate the management process of a patient with MS and seizure, include "how should we approach to the patient", "how should we treat the patient", "how should we modify the patient's MS treatment strategy", etc. METHODS: We searched the electronic database PubMed on March 30, 2018 for articles in English that included the following search terms: "epilepsy" AND "multiple sclerosis" or "seizure" AND "multiple sclerosis" since 2013, to obtain the best recent relevant scientific evidence on the topic. A working group of 6 epilepsy and 5 MS experts took part in two consensus workshops in Tehran, Iran, in 2018. The final consensus manuscript was prepared and approved by all participants.

RESULTS

The search with words "seizure" and "multiple sclerosis" yielded 121 entries; 10 were relevant to the topic. The search with words "epilepsy" and "multiple sclerosis" yielded 400 entries; 7 were relevant to the topic. We reviewed these 17 articles and also some other references, derived from these articles or relevant to the topic, for the purpose of our review.

CONCLUSION

Cooccurrence of a seizure in a patient with MS may complicate the management process. In this review, we tried to provide answers to the frequently asked questions, considering the best available scientific evidence and expert opinion.

Pathologic Findings of Chronic PML-IRIS in a Patient with Prolonged PML Survival Following Natalizumab Treatment

Immune reconstitution inflammatory syndrome (IRIS) is a common complication during treatment for natalizumab-associated progressive multifocal leukoencephalopathy (PML). Although severe IRIS can result in acute worsening of disability and is associated with poor prognosis, effective immune reconstitution may account for the high survival rate of this cohort of PML patients. We present pathological evidence of chronic IRIS 3.5 years after diagnosis with natalizumab-associated PML. Our case showed that the IRIS initially developed after plasma exchange therapy and resolved clinically and radiologically following a combination treatment with corticosteroids, maraviroc, and cidofovir. Autopsy 3.5 years later revealed evidence of grey-white matter junction demyelinating lesions characteristic of PML and perivascular leukocyte infiltrates predominated by CD8⁺ T-lymphocytes, and polymerase chain reaction analysis demonstrated the presence of JC viral DNA in this tissue, indicative of persistent PML-IRIS. While clinical symptoms of PML-IRIS typically stabilize within 6 months, our case report suggests that prolonged low-grade inflammation may persist in some patients. Better assays are needed to determine the prevalence of prolonged low-grade IRIS among PML survivors.

Progressive multifocal leukoencephalopathy and immune reconstitution inflammatory syndrome (IRIS)

Progressive multifocal leukoencephalopathy is a viral encephalitis induced by the John Cunningham (JC) virus, an ubiquitous neurotropic papovavirus of the genus polyomavirus that in healthy people in latency resides in kidney and bone marrow cells. Activation and entry into the CNS were first seen in patients with malignancies of the hematopoietic system and an impaired immune system. During the 1980 and the 1990s with the appearance of human immunodeficiency virus infection in humans, PML was found to be the most important opportunistic infection of the central nervous system. As a result of highly efficient immunosuppressive and immunomodulatory treatments, in recent years, the number of PML cases again increased. PML is prevented by an intact cellular immune response and accordingly immune reconstitution can terminate established disease in the CNS. However, forced immune reconstitution can lead to massive destruction of virus-infected cells. This may result in clinical exacerbation associated with high morbidity and mortality and referred to as PML with immune reconstitution inflammatory syndrome (PML-IRIS). In the present review, we discuss virological properties and routes of infection in the CNS, but mostly focus on the pathology of PML and PML-IRIS and on the role of the immune system in these disorders. We show that PML and PML-IRIS result from predominant JC virus infection of oligodendrocytes and, to a lesser extent, of infected neurons. Inflammation in these encephalitides seems to be driven by a dominant cytotoxic T cell response which is massively exaggerated during IRIS.

Management of disease-modifying treatments in neurological autoimmune diseases of the central nervous system

The therapeutic armamentarium for autoimmune diseases of the central nervous system, specifically multiple sclerosis and neuromyelitis optica, is steadily increasing, with a large spectrum of immunomodulatory and immunosuppressive agents targeting different mechanisms of the immune system. However, increasingly efficacious treatment options also entail higher potential for severe adverse drug reactions. Especially in cases failing first-line treatment, thorough evaluation of the risk-benefit profile of treatment alternatives is necessary. This argues for the need of algorithms to identify patients more likely to benefit from a specific treatment. Moreover, paradigms to stratify the risk for severe adverse drug reactions need to be established. In addition to clinical/paraclinical measures, biomarkers may aid in individualized risk-benefit assessment. A recent example is the routine testing for anti-John Cunningham virus antibodies in natalizumab-treated multiple sclerosis patients to assess the risk for the development of progressive multi-focal leucoencephalopathy. Refined algorithms for individualized risk assessment may also facilitate early initiation of induction treatment schemes in patient groups with high disease activity rather than classical escalation concepts. In this review, we will discuss approaches for individiualized risk-benefit assessment both for newly introduced agents as well as medications with established side-effect profiles. In addition to clinical parameters, we will also focus on biomarkers that may assist in patient selection.

Efficacy and side effects of natalizumab therapy in patients with multiple sclerosis

Natalizumab (Nat) is a humanized monoclonal antibody used for the treatment of relapsing multiple sclerosis (MS). Nat inhibits lymphocyte migration via the blood brain barrier (BBB) by blockage of an integrin adhesion molecule, very late antigen 4. During the phase III clinical trials, it was shown that Nat reduces disease activity and prevents disability progression. In addition, several smaller studies indicate a positive influence of Nat on cognition, depression, fatigue, and quality of life (Qol). Therapeutic efficacy has to be weighed against the risk of developing potentially fatal progressive multifocal leukoencephalopathy (PML), an opportunistic infection by JC-virus (JCV) with an incidence of 3.4/1000 (95% CI 3.08–3.74) in Nat treated MS patients. In this review article, we will review data on the presumed mechanism of Nat action, clinical and paraclinical efficacy parameters, and adverse drug reactions with a special focus on PML.