Temporal relationship between environmental influenza A and Epstein-Barr viral infections and high multiple sclerosis relapse occurrence.

BACKGROUND: Multiple sclerosis (MS) relapses have been associated with viral and bacterial infection epidemics in MS patients who have not used interferon. OBJECTIVES: We studied whether environmental viral infections in the general population can be associated with increased MS relapse occurrence using retrospective data from 1986 to 1995 when interferons were not yet available. METHODS: Logistic regression modelling was used to compare retrospectively the monthly relapse occurrence from 407 MS patients in Turku University hospital archives and data on ten different specifically diagnosed viral infection epidemics in the general population of Southwestern Finland from 1986 to 1995. The outcome was the odds ratio (OR) of very high relapse occurrence versus low relapse occurrence, or moderate versus low relapse occurrence. RESULTS: After a peak in diagnosed influenza A cases in the general population, the MS relapse occurrence was 6.5 times more likely to be very high (95% CI 1.8-24.0) and 7.1 times more likely to be moderately high (95% CI 1.5-33.2). An increase in MS relapse counts also followed Epstein-Barr virus (EBV) infections (OR 4.4, 95% CI 1.3-15.1), but we found no significant association with adenovirus infections and MS relapses. The MS relapse occurrence was lowest in the summer months July-August (Chi-square test, p<0.01). CONCLUSIONS: Our findings suggest that influenza A and EBV viral infections in the general population are associated with a higher occurrence of exacerbations in MS patients, and thus environmental infection data should be included in epidemiological models on MS relapses.

Downregulation of VLA-4 on T cells as a marker of long term treatment response to interferon beta-1a in MS.

We determined longitudinally the expression of a panel of adhesion molecules on T cells and soluble ICAM-1, VCAM-1 and tumor necrosis factor apoptosis inducing ligand (TRAIL) in serum during first year of the PRISMS Study with IFNbeta1a in MS. Clinical data and quantitative MRI data were available for 4 years. VLA-4 was down-regulated on T cells and VCAM-1 was up-regulated in serum during the first 3 to 6 months of therapy in patients with favorable long-term treatment response (EDSS progression

HLA class II associated risk and protection against multiple sclerosis-a Finnish family study.

We analyzed the HLA class II haplotypes in 249 Finnish nuclear families and compared the frequencies of parental haplotypes transmitted or non-transmitted to multiple sclerosis (MS) patients. The most important predisposing haplotype was DRB1*15-DQB1*0602 (P<10(-6)) as expected and a weak predisposing effect of DRB1*04-DQB1*0302 was revealed after the elimination of DRB1*15-DQB1*0602. HLA-DRB1*01-DQB1*0501 and DRB1*13-DQB1*0603 were negatively associated with MS in transmission disequilibrium test, but only the DRB1*13-DQB1*0603 association remained significant (P=0.008) after the elimination of DRB1*15-DQB1*0602 haplotypes. Based on this study HLA class II haplotypes exhibit both predisposing and protective effects in MS.