Why Auto immune Diseases Occurs?
Pathophysiology of autoimmune diseases.
Our body is gifted with a very good protective mechanism that protects our body from invasion of pathogenic bacteria and parasites, foreign antigens and cancer tumors as well. It is done by following a systematic mechanism of cellular and humoral immunity. But sometimes the same mechanism starts working against our own body organs. That’s one of the several reasons why autoimmune Diseases occurs.
1) Identification of the pathogen.
2) Identification of the pathogen is it an outsider, like virus or bacteria or parasite?
3) Presentation of the outside invaders pathogens by Dendritic Cells to body defense system, The B-Lymphocytes cells.
4) B-Lymphocytes and phagocytes get activated and start the mechanism of phagocytosis, and production of antibodies, which help in neutralizing the pathogenic antigen by antigen antibody complex formation.
Why Autoimmune diseases occurs?
Because autoimmune diseases are caused by the attack of the immune system on the self-body tissues and organs. The process of development of autoimmune disease is very complex. Therefore the treatment as well. The body protective mechanism that is supposed to attack on the invading pathogens starts attacking on the once body tissue and organs. Our body falsely recognizing them as foreign invaders.
There are about 80 autoimmune diseases identified so far.
The main defect occurs at step 3. Presentation of the tissue to B-Lymphocytes as foreign matter. This is why autoimmune Diseases Occurs.
Dendritic cells pick up the pathogens by process of pinocytosis, engulf the pathogen, body tissue matter, self-organ proteins and present it to the immune response cells the B-Cells, and Monocytes and Basophils and neutrophils.
B-Lymphocytes produce antibodies against the body organ. After the body organ tissues are falsely presented by dendritic cells to B- Lymphocytes. As foreign harmful matter to B- Lymphocytes. B-Lymphocytes start producing antibodies against the self-tissues and self-body organs.
Example of Autoimmune Disease.
Beta cells in pancreas producing insulin are falsely presented by dendritic cells to B-Lymphocytes and phagocytes monocytes and granulocytes start their defense mechanism against pancreas and damage pancreas. Damage to beta cells in the pancreas causes type 1 Diabetes.
This misrepresentation of the self body organ as harmful antigen along with the actual harmful antigens like foreign matters like pathogen bacteria virus or parasite is because of following reasons.
1)The end product of the digestion by dendritic cells, of the actual antigen and the self-body tissue comes out to be the same.
2.Cross antigenicity: This is one of the main reasons for autoimmune diseases. One antigen when presented as harmful, this antigen is also responsible for developing immune reactions against self-body tissues and body organs.
3.After once the self-body organs are represented as foreign pathogenic harmful antigen by dendritic cells. They are (self-body organs, tissues) forever recognized as foreign harmful antigens.
This is due to B-Lymphocytes which work as memory cells. B-lymphocytes recognise self-body organs, tissues as a foreign harmful antigen. Same mechanism is responsible for producing immunity after vaccination.We tried to answer the question why autoimmune Diseases occurs? In a very short way. Let’s see which are the diseases and disorders caused by Autoimmune Diseases.