Renaud Du Pasquier

Cognitive dysfunction in HIV patients despite long-standing suppression of viremia.

Objective:To determine the prevalence of cognitive complaints and HIV-associated neurocognitive disorders (HANDs) in a cohort of aviremic HIV-positive patients. To evaluate the relevance of the HIV dementia scale to detect HANDs. Design:Assessment of HANDs with neuropsychological tests. Methods:Two hundred HIV-infected patients with undetectable HIV-1 RNA concentrations in the plasma, no history of major opportunistic infection of the central nervous system in the past 3 years, no current use of intravenous drugs, and no major depression answered a questionnaire designed to elicit cognitive complaints. Cognitive functions of 50 complaining and 50 noncomplaining HIV-positive patients were assessed. Results:Patients had undetectable HIV-1 RNA concentrations for a median time of 48 months (range 3.2–136.6). The prevalence of cognitive complaints was 27%. The prevalence of HANDs was 84% among patients with cognitive complaints (asymptomatic neurocognitive impairment 24%, mild neurocognitive disorders 52%, and HIV-associated dementia 8%) and 64% among noncomplainers (asymptomatic neurocognitive impairment 60%, mild neurocognitive disorders 4%, and HIV-associated dementia 0%; P < 0.001). A score of 14 points or less on the HIV dementia scale yielded a positive predictive value of HANDs of 92% in complainers and 82% in noncomplainers. Conclusion:The prevalence of HANDs is high even in long-standing aviremic HIV-positive patients. However, HANDs without functional repercussion in daily life (asymptomatic neurocognitive impairment) is the most frequent subtype observed. In this population, the HIV dementia scale with a cutoff of 14 points or less seems to provide a useful tool to screen for the presence of HANDs.

Strong EBV-specific CD8+ T-cell response in patients with early multiple sclerosis

Epstein-Barr virus (EBV) has been associated with multiple sclerosis (MS), however, most studies examining the relationship between the virus and the disease have been based on serologies, and if EBV is linked to MS, CD8+ T cells are likely to be involved as they are important both in MS pathogenesis and in controlling viruses. We hypothesized that valuable information on the link between MS and EBV would be ascertained from the study of frequency and activation levels of EBV-specific CD8+ T cells in different categories of MS patients and control subjects. We investigated EBV-specific cellular immune responses using proliferation and enzyme linked immunospot assays, and humoral immune responses by analysis of anti-EBV antibodies, in a cohort of 164 subjects, including 108 patients with different stages of MS, 35 with other neurological diseases and 21 healthy control subjects. Additionally, the cohort were all tested against cytomegalovirus (CMV), another neurotropic herpes virus not convincingly associated with MS, nor thought to be deleterious to the disease. We corrected all data for age using linear regression analysis over the total cohorts of EBV- and CMV-infected subjects. In the whole cohort, the rate of EBV and CMV infections were 99% and 51%, respectively. The frequency of IFN-gamma secreting EBV-specific CD8+ T cells in patients with clinically isolated syndrome (CIS) was significantly higher than that found in patients with relapsing-remitting MS (RR-MS), secondary-progressive MS, primary-progressive MS, patients with other neurological diseases and healthy controls. The shorter the interval between MS onset and our assays, the more intense was the EBV-specific CD8+ T-cell response. Confirming the above results, we found that EBV-specific CD8+ T-cell responses decreased in 12/13 patients with CIS followed prospectively for 1.0 +/- 0.2 years. In contrast, there was no difference between categories for EBV-specific CD4+ T cell, or for CMV-specific CD4+ and CD8+ T-cell responses. Anti-EBV-encoded nuclear antigen-1 (EBNA-1)-specific antibodies correlated with EBV-specific CD8+ T cells in patients with CIS and RR-MS. However, whereas EBV-specific CD8+ T cells were increased the most in early MS, EBNA-1-specific antibodies were increased in early as well as in progressive forms of MS. Our data show high levels of CD8+ T-cell activation against EBV--but not CMV--early in the course of MS, which support the hypothesis that EBV might be associated with the onset of this disease.

Immune responses to JC virus in patients with multiple sclerosis treated with natalizumab: a cross-sectional and longitudinal study

BACKGROUND Natalizumab is used to prevent relapses and progression of disability in patients with multiple sclerosis but has been associated with progressive multifocal leukoencephalopathy (PML). We aimed to better understand the associations between JC virus, which causes PML, and natalizumab treatment. METHODS We prospectively assessed patients with multiple sclerosis who started treatment with natalizumab. Blood and urine samples were tested for the presence of JC virus DNA with quantitative real-time PCR before treatment and at regular intervals after treatment onset for up to 18 months. At the same timepoints, by use of proliferation and enzyme-linked immunospot assays, the cellular immune responses against JC virus, Epstein-Barr virus, cytomegalovirus, myelin oligodendrocyte glycoprotein, and myelin oligodendrocyte basic protein (MOBP) were assessed. Humoral immune response specific to JC virus was assessed with an enzyme immunoassay. The same experiments were done on blood samples from patients with multiple sclerosis before and 10 months after the start of interferon beta treatment. FINDINGS We assessed 24 patients with multiple sclerosis who received natalizumab and 16 who received interferon beta. In patients treated with natalizumab, JC virus DNA was not detected in the blood at any timepoint. However, JC virus DNA was present in the urine of six patients and in most of these patients the concentrations of JC virus DNA were stable over time. Compared with pretreatment values, the cellular immune response was increased to cytomegalovirus at 6 months, to JC virus at 1, 9, and 12 months, and to Epstein-Barr virus and MOBP at 12 months. Humoral responses remained stable. There were no increases in cellular immune responses specific to the viruses or myelin proteins in the 16 patients treated with interferon beta. INTERPRETATION Natalizumab increases cellular immune responses specific to viruses and myelin proteins in the peripheral blood after 1 year, without evidence of viral reactivation. FUNDING Swiss National Foundation, Swiss Society for Multiple Sclerosis, and Biogen Dompé.

Intrathecal immune responses to EBV in early MS

EBV has been consistently associated with MS, but its signature in the CNS has rarely been examined. In this study, we assessed EBV‐specific humoral and cellular immune responses in the cerebrospinal fluid (CSF) of patients with early MS, other inflammatory neurological diseases (OIND) and non‐inflammatory neurological diseases (NIND). The neurotropic herpesvirus CMV served as a control. Virus‐specific humoral immune responses were assessed in 123 consecutive patients and the intrathecal recruitment of virus‐specific antibodies was expressed as antibody indexes. Cellular immune responses tested in the blood of 55/123 patients were positive in 46/55. The CD8+ CTL responses of these 46 patients were assessed in the blood and CSF using a CFSE‐based CTL assay. We found that viral capsid antigen and EBV‐encoded nuclear antigen‐1, but not CMV IgG antibody indexes, were increased in early MS as compared with OIND and NIND patients. There was also intrathecal enrichment in EBV‐, but not CMV‐specific, CD8+ CTL in early MS patients. By contrast, OIND and NIND patients did not recruit EBV‐ nor CMV‐specific CD8+ CTL in the CSF. Our data, showing a high EBV‐, but not CMV‐specific intrathecal immune response, strengthen the association between EBV and MS, in particular at the onset of the disease.

Impairment of JCV-specific T-cell response by corticotherapy Effect on PML-IRIS management?

ABSTRACT Objective: To investigate the impact of corticosteroids (CS) on the viral-specific T-cell response, in particular the JC virus (JCV)–specific one, in an attempt to determine the optimal timing of CS in the management of progressive multifocal leukoencephalopathy–immune reconstitution inflammatory syndrome (PML-IRIS). Methods: A blood draw was performed before and 7 days after the administration of IV CS to 24 patients with relapsing multiple sclerosis (MS). The phenotypic pattern of T cells was determined by CCR7 and CD45RA. To assess the impact of CS treatment on proliferative response of JCV-, influenza-, and Epstein-Barr virus (EBV)–specific T cells, a thymidine incorporation proliferation assay was performed. An intracellular cytokine staining assay was performed to determine the effect of CS treatment on the production of cytokine by virus-specific T cells. JCV T-cell assays were performed only in JCV-infected patients with MS as detected by serologies (Stratify) or detection of JCV DNA in the urine by PCR. Results: CS led T cells, CD4+ and CD8+, toward a less differentiated phenotype. There was a significant decrease of EBV-, influenza-, and JCV-specific T-cell proliferative response upon CS treatment. There was a significant decrease in the frequency of interferon (IFN) γ– and tumor necrosis factor (TNF) α–producing JCV-specific CD8+ T cells, but not EBV- or influenza-specific CD4+ or CD8+ T cells. Conclusions: CS have a profound impact on the virus-specific T-cell response, especially on JCV, suggesting that when CS are considered, they should not be given before the onset of clinical or radiologic signs of IRIS. Studies addressing directly patients with MS with natalizumab-caused PML are warranted. Classification of evidence: This study provides Class III evidence that methylprednisolone treatment decreases the frequency of JCV-specific CD8+ T cells producing IFN-γ and TNFα, impairing control of JCV, suggesting this should be used to treat but not to prevent PML-IRIS. No clinical outcomes were measured.

Serum neurofilament light chain in early relapsing remitting MS is increased and correlates with CSF levels and with MRI measures of disease severity.

Background/objectives: Neurofilament light chain (NfL) levels in the cerebrospinal fluid (CSF) of multiple sclerosis (MS) patients correlate with the degree of neuronal injury. To date, little is known about NfL concentrations in the serum of relapsing remitting multiple sclerosis (RRMS) patients and their relationship with CSF levels and magnetic resonance imaging (MRI) measures of disease severity. We aimed to validate the quantification of NfL in serum samples of RRMS, as a biofluid source easily accessible for longitudinal studies. Methods: A total of 31 RRMS patients underwent CSF and serum sampling. After a median time of 3.6 years, 19 of these RRMS patients, 10 newly recruited RRMS patients and 18 healthy controls had a 3T MRI and serum sampling. NfL concentrations were determined by electrochemiluminescence immunoassay. Results: NfL levels in serum were highly correlated to levels in CSF (r = 0.62, p = 0.0002). Concentrations in serum were higher in patients than in controls at baseline (p = 0.004) and follow-up (p = 0.0009) and did not change over time (p = 0.56). Serum NfL levels correlated with white matter (WM) lesion volume (r = 0.68, p < 0.0001), mean T1 (r = 0.40, p = 0.034) and T2* relaxation time (r = 0.49, p = 0.007) and with magnetization transfer ratio in normal appearing WM (r = −0.41, p = 0.029). Conclusion: CSF and serum NfL levels were highly correlated, and serum concentrations were increased in RRMS. Serum NfL levels correlated with MRI markers of WM disease severity. Our findings further support longitudinal studies of serum NfL as a potential biomarker of on-going disease progression and as a potential surrogate to quantify effects of neuroprotective drugs in clinical trials.

Vitamin D has a direct immunomodulatory effect on CD8+ T cells of patients with early multiple sclerosis and healthy control subjects

Little is known on a putative effect of vitamin D on CD8+ T cells. Yet, these cells are involved in the immmunopathogenesis of MS. We assessed the cytokine profile of EBV-specific CD8+ T cells of 10 early MS patients and 10 healthy control subjects with or without 1,25(OH)(2)D(3) and found that, with 1,25(OH)(2)D(3), these cells secreted less IFN-γ and TNF-α and more IL-5 and TGF-β. CD4+ T cell depletion or even culture with CD8+ T cells only did not abolish the immunomodulatory effect of 1,25(OH)(2)D(3) on CD8+ T cells, suggesting that 1,25(OH)(2)D(3) can act directly on CD8+ T cells.

PML risk stratification using anti-JCV antibody index and L-selectin.

Background: Natalizumab treatment is associated with progressive multifocal leukoencephalopathy (PML) development. Treatment duration, prior immunosuppressant use, and JCV serostatus are currently used for risk stratification, but PML incidence stays high. Anti-JCV antibody index and L-selectin (CD62L) have been proposed as additional risk stratification parameters. Objective: This study aimed at verifying and integrating both parameters into one algorithm for risk stratification. Methods: Multicentric, international cohorts of natalizumab-treated MS patients were assessed for JCV index (1921 control patients and nine pre-PML patients) and CD62L (1410 control patients and 17 pre-PML patients). Results: CD62L values correlate with JCV serostatus, as well as JCV index values. Low CD62L in natalizumab-treated patients was confirmed and validated as a biomarker for PML risk with the risk factor “CD62L low” increasing a patient’s relative risk 55-fold (p < 0.0001). Validation efforts established 86% sensitivity/91% specificity for CD62L and 100% sensitivity/59% specificity for JCV index as predictors of PML. Using both parameters identified 1.9% of natalizumab-treated patients in the reference center as the risk group. Conclusions: Both JCV index and CD62L have merit for risk stratification and share a potential biological relationship with implications for general PML etiology. A risk algorithm incorporating both biomarkers could strongly reduce PML incidence.

Status epilepticus of inflammatory etiology: a cohort study.

Objective: Inflammation-related epilepsy is increasingly recognized; however, studies on status epilepticus (SE) are very infrequent. We therefore aimed to determine the frequency of inflammatory etiologies in adult SE, and to assess related demographic features and outcomes. Methods: This was a retrospective analysis of a prospective registry of adult patients with SE treated in our center, from January 2008 to June 2014, excluding postanoxic causes. We classified SE episodes into 3 etiologic categories: infectious, autoimmune, and noninflammatory. Demographic and clinical variables were analyzed regarding their relationship to etiologies and functional outcome. Results: Among the 570 SE consecutive episodes, 33 (6%) were inflammatory (2.5% autoimmune; 3.3% infectious), without any change in frequency over the study period. Inflammatory SE episodes involved younger patients (mean age 53 vs 61 years, p = 0.015) and were more often refractory to initial antiepileptic treatment (58% vs 38%, odds ratio = 2.19, 95% confidence interval = 1.07–4.47, p = 0.041), despite similar clinical outcome. Subgroup analysis showed that, compared with infectious SE episodes, autoimmune SE involved younger adults (mean age 44 vs 60 years, p = 0.017) and was associated with lower morbidity (return to baseline conditions in 71% vs 32%, odds ratio = 5.41, 95% confidence interval = 1.19–24.52, p = 0.043) without any difference in mortality. Conclusions: Despite increasing awareness, inflammatory SE etiologies were relatively rare; their occurrence in younger individuals and higher refractoriness to treatment did not have any effect on outcome. Autoimmune SE episodes also occurred in younger patients, but tended to have better outcomes in survivors than infectious SE.

HLA-B7–Restricted EBV-Specific CD8+ T Cells Are Dysregulated in Multiple Sclerosis

It was hypothesized that the EBV-specific CD8+ T cell response may be dysregulated in multiple sclerosis (MS) patients, possibly leading to a suboptimal control of this virus. To examine the CD8+ T cell response in greater detail, we analyzed the HLA-A2–, HLA-B7–, and HLA-B8–restricted EBV- and CMV-specific CD8+ T cell responses in a high number of MS patients and control subjects using tetramers. Content in cytolytic granules, as well as cytotoxic activity, of EBV- and CMV-specific CD8+ T cells was assessed. We found that MS patients had a lower or a higher prevalence of HLA-A2 and HLA-B7, respectively. Using HLA class I tetramers in HLA-B7+ MS patients, there was a higher prevalence of MS patients with HLA-B*0702/EBVRPP-specific CD8+ T cells ex vivo. However, the magnitude of the HLA-B*0702/EBVRPP-specific and HLA-B*0702/CMVTPR-specific CD8+ T cell response (i.e., the percentage of tetramer+ CD8+ T cells in a study subject harboring CD8+ T cells specific for the given epitope) was lower in MS patients. No differences were found using other tetramers. After stimulation with the HLA-B*0702/EBVRPP peptide, the production of IL-2, perforin, and granzyme B and the cytotoxicity of HLA-B*0702/EBVRPP-specific CD8+ T cells were decreased. Altogether, our findings suggest that the HLA-B*0702–restricted viral (in particular the EBV one)-specific CD8+ T cell response is dysregulated in MS patients. This observation is particularly interesting knowing that the HLA-B7 allele is more frequently expressed in MS patients and considering that EBV is associated with MS.