Research on autoimmune diseases

Autoimmune diseases are a major burden for society and may constitute serious, sometimes incapacitating health problems at the level of the individual patient. Around 5% of the population have an autoimmune disease. At SSI, we conduct a number of epidemiological research projects on the etiology of these diseases, often utilizing nationwide health registry data.

Our research activities aim to shed light on the causes of autoimmune diseases by the use of diverse research methods; sometimes by focusing on particular common autoimmune diseases (such as e.g. multiple sclerosis, inflammatory bowel diseases, rheumatoid arthritis or systemic lupus erythematosus), and sometimes in studies focusing on certain exposures (e.g. operations, pregnancies or vaccines) as possible causal factors involved in a multitude of autoimmune diseases.

Highlighted Research Projects

Multiple Sclerosis: Occurrence, comorbidity and risk factors

Multiple sclerosis (MS) is an invalidating immune-mediated disorder of the central nervous system, which typically begins in early adulthood. The etiology of MS is still not known, but environmental factors, together with genetic susceptibility is believed to have an important role.
SSI has in collaboration with the nation-wide MS registry carried out many register studies addressing MS epidemiology and comorbidity. Right now we are doing a study concerning the MS risk among immigrants in Denmark. The incidence of MS varies considerably world-wide and Denmark is a high incidence country, which could suggest that certain environmental factors in the Danish society might contribute to the etiology of MS. We will compare MS rates among first-generation immigrants in Denmark, and their Danish born children (second-generation immigrants), to that among ethic Danes and to that in their country-of-origin, respectively, in order to evaluate the importance and timing of environmental exposures for the risk of MS.

Selected publications
Bager P, Gørtz S, Feenstra B, Andersen NN, Jess T, Frisch M, Melbye M. Increased risk of inflammatory bowel disease in families with tonsillectomy: A Danish national cohort study. Epidemiology (in press, August 13, 2018) 
Frisch M, Besson A, Clemmensen KKB, Valentiner-Branth P, Mølbak K, Hviid A. Quadrivalent human papillomavirus vaccination in boys and risk of autoimmune diseases, neurologic diseases and venous thromboembolism. Int J Epidemiol 2018;47:634-641  
Nielsen NM, Harpsøe M, Simonsen J, Stenager E, Magyari M, Koch-Henriksen N, Baker JL, Hjalgrim H, Frisch M, Bager P. Age at menarche and risk of multiple sclerosis. A prospective cohort study based on the Danish National Birth Cohort. Am J Epidemiol 2017;185:712-719
Nyboe Andersen N, Görtz S, Frisch M, Jess T. Reduced risk of UC in families affected by appendicitis: a Danish national cohort study. Gut 2017;66:1398-1402 

Morten Frisch


Morten Frisch, Consultant Physician, Epidemiologisk Forskning / Autoimmune sygdomme
T. +45 32683160 @. View profile