[Anti-MOG associated disease]. / Maladie du spectre des anticorps anti-MOG.

Myelin Oligodendrocyte Glycoprotein Antibody Associated Disease (MOGAD) is an autoimmune disease responsible for demyelination of the central nervous system that can occur in adults or children. Overlapping phenotypes between MOGAD, multiple sclerosis (MS) and neuromyelitis optica spectrum disease (NMOSD) have been described. The diagnostic criteria for MOGAD were proposed by a panel of international experts and published in 2023. Defining clinical, biological and imaging characteristics specific to this entity helps to improve diagnostic specificity. In this article, we present the clinical characteristics suggestive of MOGAD and discuss the importance of the antibody detection method and therapeutic management.

La maladie du spectre des anticorps anti-MOG (glycoprotéine de myéline oligodendrocytaire) (myelin oligodendrocyte glycoprotein antibody-associated disease, MOGAD) est une maladie autoimmune responsable d'une démyélinisation du système nerveux central pouvant survenir chez les adultes ou les enfants. Des phénotypes de chevauchement entre MOGAD, sclérose en plaques et maladie du spectre de la neuromyélite optique ont été décrits. Les critères diagnostiques de MOGAD ont été proposés par un panel d'experts internationaux et publiés en 2023. Ils permettent de définir des caractéristiques cliniques, biologiques et d'imagerie propres à cette entité, afin d'améliorer la spécificité diagnostique. Nous présentons dans cet article les caractéristiques cliniques en faveur de MOGAD, discutons de l'importance de la méthode de détection des anticorps et terminons par une mise au point sur la prise en charge thérapeutique.

[Discontinuing disease-modifying therapies in multiple sclerosis]. / Traitements de la sclérose en plaques : quand les arrêter ?

Aging in multiple sclerosis (MS) leads to altered clinical manifestations, where the pathophysiology shifts towards compartmentalized inflammation that drives clinical progression independent of relapse activity. Consequently, the effectiveness of disease-modifying therapies (DMTs) diminishes in older patients, coinciding with an elevated risk of adverse events. This raises the question of whether MS therapies should be discontinued after a certain age, which is often proposed for patients over 55 years. Studies on treatment discontinuation have shown a slight increase in disease activity, yet without significant disability progression. This suggests that the decision to stop DMTs should be discussed with older patients, considering existing comorbidities. Following the cessation of therapy, meticulous monitoring is essential.

L'avancée en âge modifie la présentation clinique de la sclérose en plaques (SEP). La physiopathologie évolue progressivement au profit d'une inflammation restreinte au système nerveux central entraînant une progression clinique indépendante des poussées. Cette évolution est associée à une baisse d'efficacité des traitements de la SEP, alors qu'en parallèle le risque de complications augmente. Se pose donc la question d'un arrêt des thérapies de la SEP après un certain âge, souvent proposé à 55 ans. Bien que les premières études suggèrent une légère reprise d'activité à l'arrêt des traitements, celle-ci n'est pas associée à une progression du handicap. L'arrêt du traitement chez les patients les plus âgés devrait donc être envisagé en prenant en compte les comorbidités. Par la suite, une surveillance méticuleuse est indispensable.

Neurological side effects and drug interactions of antiviral compounds against SARS-CoV-2.

BACKGROUND AND PURPOSE: The COVID-19 pandemic, caused by severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2), rapidly spread across the globe. Tremendous efforts have been mobilized to create effective antiviral treatment options to reduce the burden of the disease. This article summarizes the available knowledge about the antiviral drugs against SARS-CoV-2 from a neurologist's perspective. METHODS: We summarize neurological aspects of antiviral compounds against SARS-CoV-2 with full, conditional, or previous marketing authorization by the European Medicines Agency (EMA). RESULTS: Nirmatrelvir/ritonavir targets the SARS-CoV-2 3c-like protease using combinatorial chemistry. Nirmatrelvir/ritonavir levels are affected by medications metabolized by or inducing CYP3A4, including those used in neurological diseases. Dysgeusia with a bitter or metallic taste is a common side effect of nirmatrelvir/ritonavir. Molnupiravir is a nucleotide analog developed to inhibit the replication of viruses. No clinically significant interactions with other drugs have been identified, and no specific considerations for people with neurological comorbidity are required. In the meantime, inconsistent results from clinical trials regarding efficacy have led to the withdrawal of marketing authorization by the EMA. Remdesivir is a viral RNA polymerase inhibitor and interferes with the production of viral RNA. The most common side effect in patients with COVID-19 is nausea. Remdesivir is a substrate for CYP3A4. CONCLUSIONS: Neurological side effects and drug interactions must be considered for antiviral compounds against SARS-CoV-2. Further studies are required to better evaluate their efficacy and adverse events in patients with concomitant neurological diseases. Moreover, evidence from real-world studies will complement the current knowledge.

Influenza vaccination induces autoimmunity against orexinergic neurons in a mouse model for narcolepsy.

Narcolepsy with cataplexy or narcolepsy type 1 is a disabling chronic sleep disorder resulting from the destruction of orexinergic neurons in the hypothalamus. The tight association of narcolepsy with HLA-DQB1*06:02 strongly suggest an autoimmune origin to this disease. Furthermore, converging epidemiological studies have identified an increased incidence for narcolepsy in Europe following Pandemrix® vaccination against the 2009-2010 pandemic 'influenza' virus strain. The potential immunological link between the Pandemrix® vaccination and narcolepsy remains, however, unknown. Deciphering these mechanisms may reveal pathways potentially at play in most cases of narcolepsy. Here, we developed a mouse model allowing to track and study the T-cell response against 'influenza' virus haemagglutinin, which was selectively expressed in the orexinergic neurons as a new self-antigen. Pandemrix® vaccination in this mouse model resulted in hypothalamic inflammation and selective destruction of orexin-producing neurons. Further investigations on the relative contribution of T-cell subsets in this process revealed that haemagglutinin-specific CD4 T cells were necessary for the development of hypothalamic inflammation, but insufficient for killing orexinergic neurons. Conversely, haemagglutinin-specific CD8 T cells could not initiate inflammation but were the effectors of the destruction of orexinergic neurons. Additional studies revealed pathways potentially involved in the disease process. Notably, the interferon-γ pathway was proven essential, as interferon-γ-deficient CD8 T cells were unable to elicit the loss of orexinergic neurons. Our work demonstrates that an immunopathological process mimicking narcolepsy can be elicited by immune cross-reactivity between a vaccine antigen and a neuronal self-antigen. This process relies on a synergy between autoreactive CD4 and CD8 T cells for disease development. This work furthers our understanding of the mechanisms and pathways potentially involved in the development of a neurological side effect due to a vaccine and, likely, to narcolepsy in general.

Advances in Treatment of Progressive Multifocal Leukoencephalopathy.

Progressive multifocal encephalopathy (PML) is a severe demyelinating disease of the central nervous system (CNS) caused by JC virus (JCV), which occurs in immunocompromised individuals. Management of PML relies on restoration of immunity within the CNS. However, when this restoration cannot be readily achieved, PML has a grim prognosis. Innovative strategies have shown promise in promoting anti-JCV immune responses, and include T-cell adoptive transfer or immune checkpoint inhibitor therapies. Conversely, management of immune reconstitution inflammatory syndrome, particularly in iatrogenic PML, remains a major challenge. In this paper, we review recent development in the treatment of PML. ANN NEUROL 2021;90:865-873.

[Acute severe neuropathies in the context of SARS-CoV-2 infection]. / Neuropathies aiguës sévères induites par l'infection à SARS-CoV-2.

Various neuromuscular complications have been described in SARS-CoV-2 infection, especially Guillain-Barré syndrome (GBS) and Critical Illness neuromyopathy (CI-NM). Two representative cases are discussed below. It appears that GBS shares most of the characteristics of classical post-infectious GBS, but SARS-CoV-2 may contribute to the increased incidence of CI-NM. Other rare complications have been described, including Tapia Syndrome and Kawasaki-like multiple system inflammatory syndrome. The question of vaccination and the risk of immune-mediated neuropathies remains open, but the lack of reported cases is reassuring as these complications usually occur within 6 weeks after vaccination.

Différentes complications neuromusculaires ont été décrites suite à l'infection à SARS-CoV-2, notamment le syndrome de Guillain-Barré (SGB) et la neuromyopathie des soins intensifs (NMSI). Deux cas représentatifs sont discutés ici. Il apparaît que le SGB partage la plupart des caractéristiques du SGB postinfectieux classique, mais le SARS-CoV-2 pourrait participer à la majoration de l'incidence de la NMSI. D'autres complications rares ont été décrites, notamment le syndrome de Tapia et le syndrome inflammatoire multisystémique de type Kawasaki. La question de la vaccination et du risque de neuropathie à médiation immunitaire reste ouverte, mais l'absence de réaction rapportée est rassurante dans la mesure où ces complications surviennent habituellement dans les 6 semaines après la vaccination.

Area postrema syndrome: Another feature of anti-GFAP encephalomyelitis.

Anti-Glial fibrillary acidic protein (GFAP) encephalomyelitis is a recently described entity and while the spectrum of this disease has been explored, further research is needed to fully describe its phenotype. Area postrema syndrome (APS) is usually associated with neuromyelitis optica spectrum disorders (NMOSDs), whereas no case of APS has been previously reported with anti-GFAP encephalomyelitis. In this article, we report a case of APS in a 41-year-old woman in the context of anti-GFAP encephalomyelitis. This case was not associated with additional anti-AQP4 IgG and therefore extends the clinico-radiological spectrum of anti-GFAP encephalomyelitis.

CD8 T cell-mediated killing of orexinergic neurons induces a narcolepsy-like phenotype in mice.

Narcolepsy with cataplexy is a rare and severe sleep disorder caused by the destruction of orexinergic neurons in the lateral hypothalamus. The genetic and environmental factors associated with narcolepsy, together with serologic data, collectively point to an autoimmune origin. The current animal models of narcolepsy, based on either disruption of the orexinergic neurotransmission or neurons, do not allow study of the potential autoimmune etiology. Here, we sought to generate a mouse model that allows deciphering of the immune mechanisms leading to orexin(+) neuron loss and narcolepsy development. We generated mice expressing the hemagglutinin (HA) as a "neo-self-antigen" specifically in hypothalamic orexin(+) neurons (called Orex-HA), which were transferred with effector neo-self-antigen-specific T cells to assess whether an autoimmune process could be at play in narcolepsy. Given the tight association of narcolepsy with the human leukocyte antigen (HLA) HLA-DQB1*06:02 allele, we first tested the pathogenic contribution of CD4 Th1 cells. Although these T cells readily infiltrated the hypothalamus and triggered local inflammation, they did not elicit the loss of orexin(+) neurons or clinical manifestations of narcolepsy. In contrast, the transfer of cytotoxic CD8 T cells (CTLs) led to both T-cell infiltration and specific destruction of orexin(+) neurons. This phenotype was further aggravated upon repeated injections of CTLs. In situ, CTLs interacted directly with MHC class I-expressing orexin(+) neurons, resulting in cytolytic granule polarization toward neurons. Finally, drastic neuronal loss caused manifestations mimicking human narcolepsy, such as cataplexy and sleep attacks. This work demonstrates the potential role of CTLs as final effectors of the immunopathological process in narcolepsy.

[Management of peripheral neuropathy in general internal medicine]. / Prise en charge des neuropathies périphériques en médecine interne générale.

Peripheral neuropathies are frequent in clinical practice and portend severe functional limitations or neuropathic pain. History taking and clinical examination represent key features to trigger investigations and uncover the underlying affection. For general internal medicine practitioners, initial investigation should include search for alcohol consumption, diabetes mellitus, vitamin B12 deficiency and monoclonal gammapathy. Nerve conduction studies should be limited to patients with atypical presentations and/or without a defined etiology. After treatment of specific etiologies, supportive care includes management of neuropathic pain and physical rehabilitation.

Les neuropathies périphériques sont fréquentes en pratique clinique, avec parfois une limitation fonctionnelle importante ou l'apparition de douleurs. L'anamnèse et l'examen clinique constituent des éléments importants pour établir un plan d'investigation et orienter le diagnostic. Pour l'interniste généraliste, la prise en charge initiale consiste à rechercher la présence d'une consommation d'alcool à risque, d'un diabète, d'un déficit en vitamine B12 ou d'une gammapathie monoclonale. Une étude de la conduction nerveuse est réservée aux présentations atypiques et/ou sans cause claire. Hormis le traitement des étiologies réversibles, le soutien au patient passe par la gestion des douleurs neuropathiques et par une prise en charge rééducative.

Circulating follicular helper T cells exhibit reduced ICOS expression and impaired function in narcolepsy type 1 patients.

Despite genetic and epidemiological evidence strongly supporting an autoimmune basis for narcolepsy type 1, the mechanisms involved have remained largely unknown. Here, we aimed to investigate whether the frequency and function of circulating follicular helper and follicular regulatory T cells are altered in narcolepsy type 1. Peripheral blood mononuclear cells were collected from 32 patients with narcolepsy type 1, including 11 who developed disease after Pandemrix® vaccination, and 32 age-, sex-, and HLA-DQB1*06:02-matched healthy individuals. The frequency and phenotype of the different circulating B cell and follicular T cell subsets were examined by flow cytometry. The function of follicular helper T cells was evaluated by assessing the differentiation of naïve and memory B cells in a co-culture assay. We revealed a notable increase in the frequency of circulating B cells and CD4+CXCR5+ follicular T cells in narcolepsy patients compared to age-, sex- and HLA-matched healthy controls. However, the inducible T-cell costimulator molecule, ICOS, was selectively down-regulated on follicular T cells from patients. Reduced frequency of activated ICOS+ and PD1high blood follicular T cells was also observed in the narcolepsy group. Importantly, follicular T cells isolated from patients with narcolepsy type 1 had a reduced capacity to drive the proliferation/survival and differentiation of memory B cells. Our results provide novel insights into the potential involvement of T cell-dependent B cell responses in the pathogenesis of narcolepsy type 1 in which down-regulation of ICOS expression on follicular helper T cells correlates with their reduced function. We hypothesize that these changes contribute to regulation of the deleterious autoimmune process after disease onset.

Neurons and T cells: Understanding this interaction for inflammatory neurological diseases.

Central nervous system (CNS) inflammation occurs in a large number of neurological diseases. The type and magnitude of CNS inflammation, as well as the T-cell contribution, vary depending on the disease. Different animal models of neurological diseases have shown that T cells play an important role in CNS inflammation. Furthermore, recent studies of human neurological disorders have indicated a significant role for T cells in disease pathology. Nevertheless, how individual T-cell subsets affect neuronal survival, damage and/or loss remains largely unclear. In this review we discuss the processes by which T cells mediate either beneficial or deleterious effects within the CNS, with emphasis on the direct interaction between T cells and neurons, as occurs in multiple sclerosis, paraneoplastic cerebellar degeneration, and viral encephalitis. The therapeutic approaches targeting T cells and their mediators as treatment for neurological diseases are also described here.

Antibodies to myelin oligodendrocyte glycoprotein in aquaporin 4 antibody seronegative longitudinally extensive transverse myelitis: Clinical and prognostic implications.

OBJECTIVE: We aimed to investigate the frequency and clinical significance of antibodies to myelin oligodendrocyte glycoprotein (MOG-abs) in patients who presented with a first episode of seronegative aquaporin 4 antibody (AQP4-ab) longitudinally extensive transverse myelitis (LETM). METHODS: Epidemiological, clinical, and paraclinical data of 56 patients from three European centres were analysed. Patients were retrospectively tested for MOG-abs and AQP4-abs, by cell-based assays. FINDINGS: Thirteen (23.2%) patients were MOG-ab positive. Among the 56 patients, six (10.7%) converted to neuromyelitis optica (NMO), one (1.8%) to multiple sclerosis (MS), nine (16.1%) had recurrent LETM, and 40 (71.4%) remained as monophasic LETM. Compared with seronegative patients, those with MOG-abs were younger (median: 32.5 vs 44 years; p=0.007), had cerebrospinal fluid pleocytosis more frequently (94% vs 45%, p=0.003) and had better outcome (median Expanded Disability Status Scale (EDSS) 2.0 vs 3.0, p=0.027). MOG-ab positive patients also showed an increase risk of optic neuritis relapse and NMO conversion (p=0.010). CONCLUSION: Patients with MOG-abs in AQP4-ab seronegative LETM have clinical distinctive features, higher risk of optic neuritis relapses, and better outcome than patients seronegative.

Bridging the Gap: Immunotherapy in Progressive Multifocal Leukoencephalopathy: A New Hope?

Progressive multifocal leukoencephalopathy (PML) is a severe infection of the CNS occurring in immunocompromised individuals in which large demyelinating lesions are induced by polyomavirus JC (JCV). In the absence of effective antiviral treatment, control of the infection relies on restoring anti-JCV immunity. Thus, particularly in long-standing immunocompromising conditions such as organ transplantation, lymphoproliferative disorders, or idiopathic lymphopenia, new strategies to boost anti-JCV immune responses are needed. Here, we report the case of a patient developing PML in the context of kidney transplantation who received recombinant human interleukin 7 to foster immune responses against JCV. We give an overview of the immunologic mechanisms underlying the development of PML and immune restoration within the CNS after JCV infection. Immunotherapeutic strategies developed based on current understanding of the disease hold promise in managing patients with PML.

Ocrelizumab Impairs the Phenotype and Function of Memory CD8+ T Cells: A 1-Year Longitudinal Study in Patients With Multiple Sclerosis.

BACKGROUND AND OBJECTIVE: Depleting CD20+ B cells is the primary mechanism by which ocrelizumab (OCRE) is efficient in persons with multiple sclerosis (pwMS). However, the exact role of OCRE on other immune cell subsets directly or indirectly remains elusive. The purpose of this study is to characterize the dynamics of peripheral immune cells of pwMS on OCRE. METHODS: We collected blood samples from 38 pwMS before OCRE onset (T0) and at 6 and 12 months (T6, T12) after initiation. To cover the immune cell diversity, using mass cytometry time of flight, we designed a 38-parameter panel to analyze B, T, and innate immune cell markers and CNS migratory markers. In parallel, viral-specific CD8+ T-cell responses were assessed by the quantification of interferon-γ secretion using the enzyme-linked immunospot assay on cytomegalovirus, Epstein-Barr virus, and influenza stimulations. RESULTS: Beside B-cell depletion, we observed a loss in memory CD8+CD20+ and central memory CD8+ T cells but not in CD4+CD20+ T cells already at T6 and T12 (p < 0.001). The loss of memory CD8+ T cells correlated with a lower CXCR3 expression (p < 0.001) and CNS-related LFA-1 integrin expression (p < 0.001) as well as a reduced antiviral cellular immune response observed at both time points (p < 0.001). Of note, we did not observe major changes in the phenotype of the other cell types studied. Seven of 38 (18.4%) patients in our cohort presented with infections while on OCRE; 4 of which were switched from dimethyl fumarate. Finally, using a mixed linear model on mass cytometry data, we demonstrated that the immunomodulation induced by previous disease-modifying therapies (DMTs) was prolonged over the period of the study. DISCUSSION: In addition to its well-known role on B cells, our data suggest that OCRE also acts on CD8+ T cells by depleting the memory compartment. These changes in CD8+ T cells may be an asset in the action of OCRE on MS course but might also contribute to explain the increased occurrence of infections in these patients. Finally, although more data are needed to confirm this observation, it suggests that clinicians should pay a special attention to an increased infection risk in pwMS switched from other DMTs to OCRE.

Significance of Myelin Oligodendrocyte Glycoprotein Antibodies in CSF: A Retrospective Multicenter Study.

BACKGROUND AND OBJECTIVES: Although the diagnosis of myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is based on serum MOG antibodies (MOG-Abs) positivity, patients with coexisting or restricted MOG-Abs in the CSF have been reported. The aim of this study is to characterize the relevance of CSF MOG-Abs positivity in clinical practice. METHODS: Eleven medical centers retrospectively collected clinical and laboratory data of adult and pediatric patients with suspected inflammatory CNS disease and MOG-Abs positivity in serum and/or CSF using live cell-based assays. Comparisons were performed using parametric or nonparametric tests, as appropriate. Potential factors of unfavorable outcomes were explored by Cox proportional hazard models and logistic regression. RESULTS: The cohort included 255 patients: 139 (55%) women and 132 (52%) children (i.e., <18-year-old). Among them, 145 patients (56.8%) had MOG-Abs in both serum and CSF (MOG-Abs seropositive and CSF positive), 79 (31%) only in serum (MOG-Abs seropositive and CSF negative), and 31 (12%) only in CSF (MOG-Abs seronegative and CSF positive). MOG-Abs seronegative and CSF positive predominated in adults (22% vs 3% of children), presented more commonly with motor (n = 14, 45%) and sensory symptoms (n = 13, 42%), and all but 4 (2 multiple sclerosis, 1 polyradiculoneuritis, and 1 Susac syndrome) had a final diagnosis compatible with MOGAD. When comparing seropositive patients according to MOG-Abs CSF status, MOG-Abs seropositive and CSF positive patients had a higher Expanded Disability Status Scale (EDSS) at nadir during the index event (median 4.5, interquartile range [IQR] 3.0-7.5 vs 3.0, IQR 2.0-6.8, p = 0.007) and presented more commonly with sensory (45.5% vs 24%, p = 0.002), motor (33.6% vs 19%, p = 0.021), and sphincter symptoms (26.9% vs 7.8%, p = 0.001) than MOG-Abs seropositive and CSF negative. At the last follow-up, MOG-Abs seropositive and CSF positive cases had more often persistent sphincter dysfunction (17.3% vs 4.3%, p = 0.008). Compared with seropositive patients, those MOG-Abs seronegative and CSF positive had higher disability at the last follow-up (p ≤ 0.001), and MOG-Abs seronegative and CSF positive status were independently associated with an EDSS ≥3.0. DISCUSSION: Paired serum and CSF MOG-Abs positivity are common in MOGAD and are associated with a more severe clinical presentation. CSF-only MOG-Abs positivity can occur in patients with a phenotype suggestive of MOGAD and is associated with a worse outcome. Taken together, these data suggest a clinical interest in assessing CSF MOG-Abs in patients with a phenotype suggestive of MOGAD, regardless of the MOG-Abs serostatus.

La réponse interféron de type I est-elle efficace pour contrôler l'infection par HTLV-1 ?

Innate immunity plays a critical role in the host response to a viral infection. In particular, type I interferons (IFN-I) are major effectors of antiviral innate immunity. Herein, interplays between HTLV-1 and the IFN-I response are reviewed. Particular emphasis is put on virus sensing by innate immunity receptors and on anti-HTLV-1 effects of IFN-I. We also discuss HTLV-1-induced alteration of IFN-I function and how IFN-I/AZT treatment of adult T-cell leukemia/lymphoma patients can lead to complete remission despite virus-induced escape mechanisms.

Delirium in Adults With COVID-19-Related Acute Respiratory Distress Syndrome: Comparison With Other Etiologies.

BACKGROUND AND OBJECTIVES: Neurologic complications have been associated with COVID-19, including delirium. Such complications have been reported to be frequent among intensive care unit (ICU)-admitted patients. We hypothesized that the rate of neurologic complications would be higher in COVID-19 associated acute respiratory distress syndrome (ARDS) than those who develop ARDS from a different cause. METHODS: We conducted a retrospective cohort study in the adult ICU of Lausanne University Hospital, including all consecutive patients fulfilling the Berlin criteria for ARDS hospitalized between December 2017 and June 2021, stratifying exposure between COVID-19 or not. The primary outcome was delirium onset during ICU stay, defined by the confusion assessment method (CAM-ICU). Exploratory outcomes included development of neurologic complications of the central nervous system (stroke, hemorrhage, and vasculitis), critical illness weakness, and 30- and 180-day all-cause mortality. RESULTS: Three hundred eleven patients were included in the study (253 with COVID-19 and 58 with other causes) and CAM-ICU could be assessed in 231 (74.3% in COVID-19 vs 74.1% in non-COVID-19). The proportion of patients developing delirium was similar in patients with COVID-19 and controls in univariate comparison (69.1% vs 60.5%, p = 0.246). Yet, patients with COVID-19 had a higher body mass index, lower ICU severity, longer mechanical ventilation, and higher sedation doses (propofol and dexmedetomidine). After adjusting for these factors in a multivariable analysis, the risk of delirium remained comparable across groups (adjusted OR [95% CI]: 0.86 [0.35-2.1]). Similarly, COVID-19-related ARDS had no effect on all-cause mortality at 30 days (adjusted OR: 0.87 [0.39-1.92]) and 180 days (adjusted OR: 0.67 [0.33-1.35]). Finally, neurologic complications affecting the CNS (adjusted OR: 1.15 [0.25-5.29]) and critical illness weakness (adjusted OR: 2.99 [0.97-9.1]) were not higher in the COVID-19 group. DISCUSSION: Compared with other etiologies, patients with COVID-19 did not have higher incidence of delirium and other neurologic complications, after accounting for underlying disease severity in patients with ARDS. Management of COVID-19-associated ARDS needed longer invasive ventilation and higher sedation, which could explain higher rates of delirium in uncontrolled studies.

CCR5 Blockade in Inflammatory PML and PML-IRIS Associated With Chronic Inflammatory Diseases' Treatments.

BACKGROUND AND OBJECTIVES: Progressive multifocal leukoencephalopathy (PML) is a disabling neurologic disorder resulting from the infection of the CNS by JC polyomavirus in immunocompromised individuals. For the last 2 decades, increasing use of immunotherapies leads to iatrogenic PML. Iatrogenic PML is often associated with signs of inflammation at onset (inflammatory PML) and/or after treatment withdrawal immune reconstitution inflammatory syndrome (PML-IRIS). Although immune reconstitution is a key element for viral clearance, it may also be harmful and induce clinical worsening. A C-C chemokine receptor type 5 (CCR5) antagonist (maraviroc) has been proposed to prevent and/or limit the deleterious immune responses underlying PML-IRIS. However, the data to support its use remain scarce and disputed. METHODS: We conducted a multicenter retrospective cohort study at 8 university hospitals in France and Switzerland by collecting clinical, biological, and radiologic data of patients who developed inflammatory PML (iPML) or PML-IRIS related to immunosuppressive therapies used for chronic inflammatory diseases between 2010 and 2020. We added to this cohort, a meta-analysis of individual case reports of patients with iPML/PML-IRIS treated with maraviroc published up to 2021. RESULTS: Overall, 27 cases were identified in the cohort and 9 from the literature. Among them, 27 met the inclusion criteria: 16 treated with maraviroc and 11 with standard of care (including corticosteroids use). Most cases were related to MS (92.6%) and natalizumab (88%). Inflammatory features (iPML) were present at onset in 12 patients (44.4%), and most patients (92.6%) received corticosteroids within the course of PML. Aggravation due to PML-IRIS was not prevented by maraviroc compared with patients who received only corticosteroids (adjusted odds ratio: 0.408, 95% CI: 0.06-2.63). Similarly, maraviroc did not influence time to clinical worsening due to PML-IRIS (adjusted hazard ratio = 0.529, 95% CI: 0.14-2.0) or disability at the last follow-up (adjusted odds ratio: 2, 95% CI: 0.23-17.3). DISCUSSION: The use of CCR5 blockade did not help to keep deleterious immune reconstitution in check even when associated with corticosteroids. Despite maraviroc's reassuring safety profile, this study does not support its use in iPML/PML-IRIS. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence showing that adding maraviroc to the management of iatrogenic iPML/PML-IRIS does not improve the outcome.