2021/06/11

DNA changes behind Microscopic Colitis

Spotlight on microscopic colitis research at CIC bioGUNE: publication in Nature Reviews Disease Primers and prize for best basic science communication at the Spanish Society of Gastroenterology (AEG).

Microscopic colitis (MC) is a relatively common condition characterized by chronic diarrhea that affects up to 0.5% of older adults, primarily women. Two major forms of MC are recognized, collagenous colitis (CC) and lymphocytic colitis (LC), which manifest with identical symptoms and are believed to have similar, although poorly characterized etiology.  A team of experts, including Ikerbasque Professor Mauro D’Amato head of Gastrointestinal Genetics Laboratory at CIC bioGUNE, provide a state-of-the-art overview of current understanding of MC pathophysiology now published on Nature Reviews Disease Primers. (https://www.nature.com/articles/s41572-021-00273-2).

On the same line, the Gastrointestinal Genetics Lab now reports important genetic findings suggesting CC and LC are in fact different entities whose predisposition can be distinguished by looking at immune genes called Human Leukocyte Antigens (HLA). The HLA molecules are involved in the activities of the immune system and the defence against pathogens, and vary to a great extent in different individuals (one of the reasons why they need to be matched in transplantation, for example).

The researchers looked at common DNA changes in the whole genome of almost 2,000 MC patients and 13,000 healthy people from Europe and USA and detected increased disease risk in people carrying certain HLA variants, exclusively in CC and not LC. This led them to conclude that CC and LC are distinct conditions possibly caused by diverse pathogenetic mechanisms, including host-pathogen interactions mediated by the HLA molecules in collagenous colitis.

The study (entitled “No más colitis microscópica: la asociación HLA distingue la colitis colágena de la linfocítica”) was recently presented by Dr Yamile Zabana during the plenary session of the at 24ª Reunión Anual de la Asociación Española de Gastroenterología (virtual meeting June 1-4), and won the prize for best communication in the basic research category (https://www.aegastro.es/premios/premiados-y-mejores-comunicaciones-y-posters)