Rheumatoid Arthritis pathology in 5 minutes

Here is the narration exactly as it is in the video: Unfortunately, some genetic factors, bacterial or viral infection or smoking can induce mutation in the collagen II. This mutation results in replacement of arginine amino acid with citrulline amino acid. This little change has devastating lifelong sequences on the affected people. The antigen presenting cells APCs such as dendritic cells which patrol our tissues recognize this new mutated collagen. These antigen presenting cells have specific detecting molecules on their outer cell membranes called HLA molecules. Specific types of these HLA molecules which are HLA DR1 and HLA DR4 become confused and deal with the new collagen as foreign body. “phagocyte them now, phagocyte them now” As a result, the antigen presenting cells phagocyte this mutated collagen. After digesting the citrullinated collagens the APCs present some parts of the protein on their outer surface as foreign bodies On the other hand, T helper cells