Serological differences in monozygotic twin pairs discordant for multiple sclerosis

Objectives - The etiology of MS is unknown but genetic factors are supporte d by a high concordance in twins. Geographic distribution and migration stu dies indicate, however, the importance of environmental factors. Material a nd methods - We studied 3 pairs of genetically identical twins who had shar ed the same environment but were discordant for MS. Serum samples were assa yed for antibodies against 21 viruses, 4 bacteria and Toxoplasma gondii. Re sults and conclusion No common factor present only in the affected twins wa s identified but differences were found in serum titers against some neurot ropic microorganisms. In general the serum titers were strikingly similar i n the twins, indicating no major disturbances of the humoral immune system in MS.