Role of environmental factors in autoimmunity: pearls from the 10th international Congress on autoimmunity, Leipzig, Germany 2016

Excerpt

The astonishing setting of the 10th International Congress on Autoimmunity in Leipzig was the perfect frame for intense and vibrant discussions on the pathogenic mechanisms of autoimmune diseases. Several authors have focused their attention on the role played by environmental factors. The depiction of the autoimmune/inflammatory syndrome induced by adjuvants (ASIA) by Shoenfeld and Agmon-Levin in 2010 has added a piece to the complex mosaic of autoimmunity, and several scientists have put their efforts in deciphering such complex syndrome [1]. The adjuvant is any substance used to enhance a specific immune response [2]. Several effects of adjuvants on the immune system have been suggested: they can deliver antigens to the immune system; activate innate immune cells through Toll-like receptors (TLR), NOD-like receptors, helicases and C-type lectin receptors; promote the attraction of dendritic cells; increase the uptake of the antigen by antigen-presenting cells (APCs); promote the secretion of cytokines with secondary activation of APCs or activate the inflammasome [3]. A number of evidences have associated these substances with the development of autoimmune phenomena. Torres Ruiz et al. [4] have reviewed the animal models of adjuvants induced autoimmunity. These are of extreme importance because they allow a better understanding of the pathogenic mechanisms of autoimmune diseases as well as may be used to find novel potential treatments. What is becoming clearer is the fact that the development of an autoimmune reaction may require a genetically prone individual [5]. Arango et al. [6] have summarized the HLA-DRB1 haplotypes linked with different autoimmune conditions. Moreover, they revised those haplotypes associated with a higher production of antibodies against specific vaccines. It is evident that these interactions are crucial in determining the onset of an autoimmune response [7, 8]. From the clinical point of view, case reports and case series of suspected vaccine-induced autoimmunity are present in the literature. Ruhrman-Shahar et al. [9] reported on four cases of anti-tetanus vaccination and the appearance of dermatomyositis, systemic lupus erythematosus, type 1 diabetes mellitus and anti-phospholipid syndrome. These cases show a strict temporal relationship between vaccine administration and the development of the full-blown autoimmune disease. The pathogenic mechanism may be shared between an alum-induced autoimmune response and the abnormal immune reactions occurring in the course of the autoimmune conditions [10]. Nonetheless, most of the reports have been addressing the possible role of the human papilloma virus (HPV) vaccine and the development of adverse events, which may be of autoimmune origin [11]. …