Epstein-Barr Virus and multiple sclerosis in a Spanish cohort: A two-years longitudinal study.

Objectives: 1. To analyze the prevalence and levels of anti-EBNA-1 and anti-VCA IgG antibodies of Epstein-Barr virus (EBV) in a Spanish cohort of multiple sclerosis (MS) patients and their interactions with other environmental and genetic risk factors. 2. To analyze the association of the evolution of these antibodies with the clinical response to different disease modifying therapies (DMTs) after two-years of follow-up. 3. To assess their possible correlation with the class II HLA alleles as well as with several SNPs identified in GWAS related to disease susceptibility. Materials and methods: We recruited 325 MS patients without DMT (serum samples were collected 1-3 months before starting a therapy) and 295 healthy controls (HC). For each patient we also collected serum samples 6, 12, 18 and 24 months after starting the DMT. EBNA-1 and VCA IgG titers were analyzed by ELISA; 25(OH)D levels were analyzed by immunoassay; HLA DRB1*15:01 allelic variant was analyzed by Taqman technology. Results: 1. 97.8% (318/325) vs. 87.1% (257/295) positives for EBNA-1 in MS patients and HC, respectively (p<0.0001; O.R. = 6.7); 99.7% (324/325) vs. 94.6% (279/295) for VCA in MS patients and HC, respectively (p=0.0001; O.R. = 18.6). All MS patients were positive for EBNA-1 and/or VCA IgG antibodies vs. 280/295 (94.9%) HC (p<0.0001). IgG titers were also significantly higher in MS patients than in HC. 2. We did not find any statistical correlation in the variation of the EBNA-1 and VCA IgG titers between baseline and 24 month visits with the number of relapses, progression, clinical response, NEDA-3 condition or therapeutic failure. 3. When we compared different epidemiological and clinical variables between those with genetic factors associated with lower EBNA-1 IgG titers and all other MS patients, we found MS started 3.5 years later among the first. Conclusions: These results confirm that MS occurs rarely in absence of EBV. An intriguing association between genetic burden and lower EBNA-1 IgG titers was associated with an earlier age of disease onset. Similar studies with B-cell-targeted therapies should be performed.

Predictive factors and early biomarkers of response in multiple sclerosis patients treated with natalizumab.

There are an increasing number of treatments available for multiple sclerosis (MS). The early identification of optimal responders to individual treatments is important to achieve individualized therapy. With this aim, we performed a multicenter retrospective longitudinal study including 186 MS patients treated with natalizumab who were followed for 2 years. We analyzed the following variables at recruitment: sex, current age, age at disease onset, disease duration, EDSS, number of T2 and Gd + lesions, IgG and IgM oligoclonal bands, HLA class II (DR, DRB, DQA, DQB, and DRB1*15:01), IgG and IgM antibody titers against human herpesvirus 6 (HHV-6) and the antibody response to Epstein-Barr virus (EBV) through the measurement of the anti-EBNA-1 and anti-VCA IgG titers, in relation to clinical response (no relapses or disability progression), and to NEDA-3 (no evidence of disease activity in terms of clinical response and no changes in MRI scans either) after 2-years follow-up. Baseline EDSS score, baseline EBNA-1 IgG titers and percentage change of HHV6 IgG titers between baseline and 6 month visits were significantly different in clinical responders and in NEDA-3 status (all of them remained significant in the multivariate analysis). We identified three variables for the early identification of natalizumab optimal responders in a rapid and cost-effective approach.

Untreated relapsing remitting multiple sclerosis patients show antibody production against latent Epstein Barr Virus (EBV) antigens mainly in the periphery and innate immune IL-8 responses preferentially in the CNS.

BACKGROUND: Multiple sclerosis (MS) is an inflammatory and neurodegenerative disorder of the central nervous system (CNS). Reliable biomarkers are urgently needed for its diagnosis and management, and as clues to its pathogenesis, in which EBV is implicated. OBJECTIVE: To measure IgG antibodies against EBV nuclear antigen-1 (EBNA-1) and innate inflammation status in paired serum and cerebrospinal fluid (CSF) samples from untreated relapsing-remitting MS (RRMS) patients. MATERIALS AND METHODS: Anti-EBNA-1 IgG titers and IL-8, IL-1ß, IL-6, IL-10, TNF-α and IL-12p70 cytokine levels were measured in 20 untreated RRMS-patients and 17 healthy controls. RESULTS: We found higher serum anti-EBNA-1 IgG and IL-8 levels in RRMS-patients than in healthy controls. Interestingly, levels of IL-8 - relative to total protein - were much higher in the CSF, whereas the anti-EBNA-1 antibodies were significantly higher in the sera. More detailed analysis showed that anti-EBNA-1 antibodies relative to total IgG were also higher in the serum in the majority of RRMS patients compared to CSF. Levels of anti-EBNA-1 IgG and IL-8 showed a strong correlation between serum and CSF. CONCLUSION: These findings in newly diagnosed RRMS-patients imply anti-EBNA-1 antibody production mainly in the periphery and innate immune responses preferentially in the CNS. Both their potential as disease biomarkers and their implications for the pathogenesis of MS warrant further investigation.

Procedimiento de validación de un método para cuantificar cobalto en suero por espectroscopia de absorción atómica con atomización electrotérmica / Validation of a method to quantify cobalt in serum by electrothermal atomic absorption spectrometry

El interés en la medida de cromo es debido al problema existente con las prótesis metal-metal. Estas liberan cromo a la circulación sanguínea y a los tejidos produciendo efectos perjudiciales para la salud. El objetivo de este estudio es validar un método para la medida de cromo en suero mediante espectroscopía de absorción atómica con atomización electrotérmica y corrección de fondo por efecto Zeeman longitudinal. Los límites de detección y cuantificación fueron de 0,074 y 0,247 μg/L, respectivamente. La masa característica encontrada fue de 7,1 pg/0,0044 unidades de absorbancia. La curva de calibración es lineal entre 0 y 10 μg/L. La pendiente obtenida con adiciones estándar de cromo está incluida dentro del intervalo de confianza de la curva de calibración con patrones acuosos, por tanto no hay efecto matriz. Se comprobó la exactitud y precisión empleando material de referencia Seronorm Trace Elements Serum. La recuperación media obtenida fue de 99,32%. El método propuesto resultó sensible, robusto, exacto y preciso para el análisis de cromo en suero como indicador de riesgo para la salud (AU)

The interest of measuring chromium in serum is due to the problem with metal-on-metal bearings. They release this metal into tissues and the blood circulation producing harmful effects on health. The aim of this study is to validate a method for chromium determination in serum samples by electrothermal atomization atomic absorption spectrometry technique with longitudinal Zeeman-effect background correction. The features of the method were proved. The detection and quantification limits were 0.074 y 0.247 μg/L, respectively. The characteristic mass was 7.1 pg/0.0044 absorbance units. The calibration curve is linear between 0 and 10 μg/L. The slope of the standard addition curve is included within the confidence interval of the calibration curve using aqueous standards, so that, there is not matrix effect. The precision and accuracy were tested using reference material Seronorm Trace Elements Serum. The mean recovery was 99.32%. The proposed method proves to be sensitive, robust, accurate and precise for biomonitoring the concentration of chromium in serum samples as an indicator of health risk (AU)

Procedimiento de validación de un método para cuantificar cromo en suero por espectroscopía de absorción atómica con atomización electrotérmica / Procedure for validating an electrothermal atomization atomic absorption spectrometry method for quantifying chromium in serum

El interés en la medida de cromo es debido al problema existente con las prótesis metal-metal. Estas liberan cromo a la circulación sanguínea y a los tejidos produciendo efectos perjudiciales para la salud. El objetivo de este estudio es validar un método para la medida de cromo en suero mediante espectroscopía de absorción atómica con atomización electrotérmica y corrección de fondo por efecto Zeeman longitudinal. Los límites de detección y cuantificación fueron de 0,074 y 0,247 μg/L, respectivamente. La masa característica encontrada fue de 7,1 pg/0,0044 unidades de absorbancia. La curva de calibración es lineal entre 0 y 10 μg/L. La pendiente obtenida con adiciones estándar de cromo está incluida dentro del intervalo de confianza de la curva de calibración con patrones acuosos, por tanto no hay efecto matriz. Se comprobó la exactitud y precisión empleando material de referencia Seronorm Trace Elements Serum. La recuperación media obtenida fue de 99,32%. El método propuesto resultó sensible, robusto, exacto y preciso para el análisis de cromo en suero como indicador de riesgo para la salud (AU)

The interest of measuring chromium in serum is due to the problem with metal-on-metal bearings. They release this metal into tissues and the blood circulation producing harmful effects on health. The aim of this study is to validate a method for chromium determination in serum samples by electrothermal atomization atomic absorption spectrometry technique with longitudinal Zeeman-effect background correction. The features of the method were proved. The detection and quantification limits were 0.074 y 0.247 μg/L, respectively. The characteristic mass was 7.1 pg/0.0044 absorbance units. The calibration curve is linear between 0 and 10 μg/L. The slope of the standard addition curve is included within the confidence interval of the calibration curve using aqueous standards, so that, there is not matrix effect. The precision and accuracy were tested using reference material Seronorm Trace Elements Serum. The mean recovery was 99.32%. The proposed method proves to be sensitive, robust, accurate and precise for biomonitoring the concentration of chromium in serum samples as an indicator of health risk (AU)