Can serum GAD65 antibody levels predict neurological disease or cancer?

The clinical relevance of antibodies that bind to glutamic acid decarboxylase 65 (GAD65) is controversial regarding diagnostic utility in screening for neurological disease or cancer. We did a retrospective study of 3152 GAD65 antibody-positive patients to examine whether analysis of the antibody levels could predict neurological disease or cancer. Serum GAD65 antibody levels were not associated with any of the following groups: neurological disease, neurological disease and diabetes, diabetes only, no neurological diagnosis and no diabetes mellitus, or cancer. Analysis of serum GAD65 antibody levels had no prognostic value in neurological disease or cancer. GAD65 antibodies should therefore be measured in selective cases of autoimmune neurological diseases.

Guillain-Barré syndrome and adjuvanted pandemic influenza A (H1N1) 2009 vaccines: a multinational self-controlled case series in Europe.

BACKGROUND: The risk of Guillain-Barré syndrome (GBS) following the United States' 1976 swine flu vaccination campaign in the USA led to enhanced active surveillance during the pandemic influenza (A(H1N1)pdm09) immunization campaign. This study aimed to estimate the risk of GBS following influenza A(H1N1)pdm09 vaccination. METHODS: A self-controlled case series (SCCS) analysis was performed in Denmark, Finland, France, Netherlands, Norway, Sweden, and the United Kingdom. Information was collected according to a common protocol and standardised procedures. Cases classified at levels 1-4a of the Brighton Collaboration case definition were included. The risk window was 42 days starting the day after vaccination. Conditional Poisson regression and pooled random effects models estimated adjusted relative incidences (RI). Pseudo likelihood and vaccinated-only methods addressed the potential contraindication for vaccination following GBS. RESULTS: Three hundred and three (303) GBS and Miller Fisher syndrome cases were included. Ninety-nine (99) were exposed to A(H1N1)pdm09 vaccination, which was most frequently adjuvanted (Pandemrix and Focetria). The unadjusted pooled RI for A(H1N1)pdm09 vaccination and GBS was 3.5 (95% Confidence Interval (CI): 2.2-5.5), based on all countries. This lowered to 2.0 (95% CI: 1.2-3.1) after adjustment for calendartime and to 1.9 (95% CI: 1.1-3.2) when we accounted for contra-indications. In a subset (Netherlands, Norway, and United Kingdom) we further adjusted for other confounders and there the RI decreased from 1.7 (adjusted for calendar month) to 1.4 (95% CI: 0.7-2.8), which is the main finding. CONCLUSION: This study illustrates the potential of conducting European collaborative vaccine safety studies. The main, fully adjusted analysis, showed that the RI of GBS was not significantly elevated after influenza A(H1N1)pdm09 vaccination (RI = 1.4 (95% CI: 0.7-2.8). Based on the upper limits of the pooled estimate we can rule out with 95% certainty that the number of excess GBS cases after influenza A(H1N1)pdm09 vaccination would be more than 3 per million vaccinated.

Immunotherapies influence the influenza vaccination response in multiple sclerosis patients: an explorative study.

BACKGROUND: The immunogenicity of influenza vaccines in MS patients undergoing immunomodulatory treatment is not well studied. OBJECTIVES: This explorative study investigated the influence of immunomodulatory treatment on MS patients receiving pandemic H1N1 (swine flu) vaccination in 2009 and seasonal influenza vaccination in 2010. METHODS: We investigated the immune response to pandemic H1N1 vaccination among 113 MS patients and 216 controls during the pandemic of 2009. We also investigated the serological response to seasonal influenza vaccination (2010 - 2011 season) among 49 vaccinated and 62 non-vaccinated MS patients, versus 73 controls. We evaluated these vaccine responses by haemagglutination inhibition assay. RESULTS: MS patients receiving immunomodulatory treatment had reduced protection (27.4%), compared to controls (43.5%) (p = 0.006), after pandemic H1N1 vaccination (2009). The rates of protection were not influenced by interferon beta treatment (44.4% protected), but were reduced among patients receiving glatiramer acetate (21.6%), natalizumab (23.5%), and mitoxantrone (0.0%). A similar pattern emerged after MS patients received a seasonal influenza vaccination in 2010. CONCLUSIONS: These findings suggest that MS patients receiving immunomodulatory therapies other than interferon beta should be considered for a vaccine response analysis and perhaps be offered a second dose of the vaccine, in cases of insufficient protection.