[Risk factors of multiple sclerosis in Moscow population. I. Exogenous risk factors]

Descriptive epidemiologic investigations revealed the necessity of the exogenous influence for the development of multiple sclerosis (MS). By means of "case-control" method the relations of MS with exogenous factors were studied. On the first stage there were analysed questionnaire data on 250 "patient-control" pairs matched by age, sex, nationality and birth in Moscow or out of it. The questionnaire was elaborated on the basis of the epidemiologic one recommended for the epidemiologic studies in the countries of South-East Europe. Significant correlations were found between MS and exogenous factors, namely: "tonsillitis at the age under 15 years" and "predominance of meat in the diet at the age under 15 years". These associations were confirmed by the data of both stratificative, discriminative analysis and logic regression. More detailed questionnaire was used on the second stage in 110 "patient-control" pairs. The second study confirmed such associations and found the most significant connection between MS and both tonsillitis at the age of 7-15 years and consumption of smoked meat. The influence of both exogenous factors were probably conditioned by permanent antigenic stimulation of the immune system in predisposed individuals.