Autoimmune Diseases

Autoimmune disease = a condition has to result from an attack of B & T cells.

Autoimmune diseases are multifactorial and chronic, and the term encompasses nearly 100 different conditions (9). They are characterized by an immune system that erroneously attacks healthy host cells; examples include Multiple sclerosis (MS), Type 1 Diabetes (T1D), rheumatoid arthritis, systemic lupus erythematosus (SLE) and Inflammatory Bowel Disease (IBD) (1).

Typically, patients with autoimmune disease exhibit decreased abundances of tolerogenic Interleukin-10 (IL-10)-producing CD4+ CD25+ FOXP3 high Treg (peripherally induced) and an increased abundance of autoreactive, effector T cell subsets such as CD4+ Th1 Cells and CD4+ Th17 cells, which shift the ratio of Treg cells to effector T cells away from a homeostatic state level (2).

During the past century, the incidence of autoimmune diseases has overtaken that of infectious diseases in industrialized countries (3)

Although there appears to be some genetic component, studies of disease discordant twins have found that concordance rates are incomplete and, therefore, environmental factors, including the gut microbiome, likely contribute to disease development (4, 5). MHC-ll strongly correlates to most autoimmune disease (10).

Factors prominent in northern populations - circadian rhythm disruption and vitamin D deficiencies— have also resulted in immune dysregulation via shifts in gut microbiota, leading to autoimmune diseases like Type 1 Diabetes (T1D) (6, 7, 8).

With a few exceptions (e.g., Sardinia, Italy), autoimmune disease incidence follows a north-south trajectory, with higher incidences in Nordic countries, such as Finland, Sweden, and Norway (11, 12).

References:

(1) Wolter et al. 2021 Nat Rev Gastroenterol Hepatol 18(12): 885-902
(2) Ohkura et al. 2020 Immunity 52: 111-1132
(3) Bach 2002 N. Engl. J. Med. 347: 911-920
(4) Berer et al. 2017 Proc. Natl. Acad. Sci. USA 114: 10719-10724
(5) Horta-Baas et al. 2017 J. Immunol. Res. 2017: 4835189
(6) Voigt et al. 2014 PLoS ONE 9: e97500
(7) Liang et al. 2015 Proc Natl Acad Sci USA. 112: 10479-84
(8) Voigt et al. 2016 Int Rev Neurobiol. 131:193-205
(9) Wang et al. 2015 J. Intern. Med. 278: 369-395
(10) van den Hoorn et al., 2011
(11) Maahs et al. 2010 Endocrinol Metab Clin North Am. 39: 481-97
(12) Patterson et al. 2009 Lancet 373: 2027-33

see also:
Self antigens / Autoantigens / Autoimmunity