[Smoking as a risk factor of development and progression of multiple sclerosis (a review and experimental data)].

Epidemiological data on smoking influence on the development and course of multiple sclerosis (MS) are presented. The relative risk (RR) of MS for smokers was calculated as 1.3-1.8 in various cohort studies. Smoking was positively correlated with MS progression. The RR of the transition of remitting-relapsing MS to secondary progressive MS was in the range of 2.5-3.6. The RR of the transition to clinically isolated syndrome authentic MS was 1.8. Results of the MRI study of 239 MS patients (102 smokers and 137 non-smokers) revealed the higher level of disability on EDSS, higher rate of disease progression and lesser cases with remitting course in the group of smokers. The primary progressive MS course was more often observed in the group of smoking patients. The more favorable prognosis in terms of sensitivity and visual symptoms of disease onset were found in nonsmokers.Forms with a late onset prevailed in smokers.