A case‐control study of multiple sclerosis

Abstract

We conducted a study of 145 persons with multiple sclerosis who had been identified in a 1970 survey and 145 friend controls, to investigate whether the development of MS was associated with exposure to uncommon viruses or an older age at infection with 1 or more common viruses. The most striking finding was a strong positive association for history of infectious mononucleosis (IM), suggesting older age at exposure to Epstein-Barr virus, the most common etiologic agent of IM. We also found significant positive associations for number of different domiciles before adulthood and for visits outside the United States; both would be compatible with an increased likelihood among cases of exposures to uncommon viruses or to multiple strains of a common agent. Cases were younger at menarche, increasing the probability of viral exposure after puberty.

Environmental triggers of multiple sclerosis

“…Interestingly, compelling evidence support the association of IM with elevated risk of MS occurrence [11][12][13][14]. Based on a recent updated meta-analysis evaluating a total of 18 clinical studies, the combined relative risk for development of MS after IM was estimated at 2.17 (95% CI 1.97-2.39; P < 10 À54 ) [15], while when analyzed in HLA-DRB1Ã15 carriers individuals with history of IM had a sevenfold increased risk of developing the disease [16].…”

Epstein-Barr Virus: Environmental Trigger of Multiple Sclerosis?

“…Epidemiological studies first reported a positive association between a history of IM and the occurrence of MS (50,56,58). A recent cohort study consisting of more than 25,000 Scandinavian patients with IM who were followed up for the occurrence of MS (56) and a meta-analysis of smaller previous studies on the association of IM and MS pointed out that individuals with a history of IM have a more-than-twofoldincreased risk of developing MS compared to subjects who acquired the virus without symptoms (74).…”

Multiple Sclerosis and Epstein-Barr Virus

“…The studies frequently failed to blind laboratory procedures or describe their sources of cases and controls. Case-control studies Nine case-control studies were identified (25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35). One 'A', four 'B', two 'C' and two 'D' ratings were assigned (Tables 3, 4).…”

“…There were two 'D' studies (30,32). Operskalski et al (32) found that cases were much more likely than controls to report a history of IM (OR 17.0, 95% CI 2.0 to 81.8).…”

“…Operskalski et al (32) found that cases were much more likely than controls to report a history of IM (OR 17.0, 95% CI 2.0 to 81.8). This study used prevalent cases without stating diagnostic criteria, and a study collaborator interviewed all subjects.…”