Evolution of antibody titres against Epstein-Barr virus and human herpesvirus 6A/B and expression of multiple sclerosis-associated retrovirus in the serum of pregnant multiple sclerosis patients.

Epstein-Barr virus (EBV), human herpesvirus 6A/B (HHV-6A/B) and multiple sclerosis (MS)-associated retrovirus (MSRV) have been described as possible MS triggers. We analysed antibody titres against EBV and HHV-6, and MSRV envelope (env) mRNA expression, in the serum of pregnant multiple sclerosis patients (P-MS) to study their possible link to the clinical activity of MS during pregnancy and postpartum and their possible role as relapse predictors. For that purpose, serum samples were collected from 71 pregnant women (50 pregnant MS and 21 pregnant healthy controls-P-HC) during pregnancy and postpartum. Relating to antibody titres, IgM antibody titres against HHV-6A/B were significantly higher in P-MS than in P-HC both in each pregnancy trimester and in the postpartum period. Moreover, IgM antibody titres against HHV-6A/B were higher in P-MS who suffered a relapse during the postpartum. Regarding MSRV env mRNA expression, the prevalence in the first trimester of pregnancy was significantly higher in P-MS who suffered relapses during pregnancy. Summing it up, high IgM antibody titres against HHV-6A/B and MSRV env mRNA expression during the first trimester of pregnancy could act as relapse predictors for the gestation/postpartum periods.

Anti-JC virus seroprevalence in a Spanish multiple sclerosis cohort: JC virus seroprevalence in Spain.

OBJECTIVE: To estimate the seroprevalence of anti-JCV antibodies, seroconverting rates and evolution of antibody levels in a multiple sclerosis (MS) Spanish cohort. METHODS: Multicenter, retrospective cross-sectional and longitudinal study. The JCV seroprevalence was analyzed in 711 MS patients by using 1st (STRATIFY-1) and 2nd generation (STRATIFY-2) two-step ELISA over 2.65 (±0.97) years. Seroconversion rate was obtained over 2 samples from 314 patients, and index stability from 301 patients with 3 or more samples available. The effect of each ELISA generation, demographics, clinical characteristics and therapy on seroprevalence was assessed by logistic regression. RESULTS: The overall anti-JCV seroprevalence was 55.3% (51.6-58.9), similar across regions (p=0.073). It increased with age (p<0.000) and when STRATIFY-2 was used (60.5%, p=0.001). Neither sex nor immunosuppressive therapy had any influence. Yearly seroconversion rate was 7% (considering only STRATIFY-2). Serological changes were observed in 24/301 patients, 5.7% initially seropositive reverted to seronegative and 7% initially seronegative changed to seropositive and again to seronegative, all these cases had initial index values around the assay's cut-off. CONCLUSIONS: JCV seroprevalence in Spanish MS patients was similar to that reported in other European populations. Changes in serostatus are not infrequent and should be considered in clinical decisions.