Q: I am a 37 years old male. I want to know whether auto-immune system leads to rheumatoid arthritis.

A:The immunopathogenesis of rheumatoid is a complex interaction of genetic factors (large number of genes have been identified, shared-epitope being the best characterised) with some known (smoking has the strongest link) and some unknown environmental factors. This leads to the breakdown in 'self-tolerance' mechanism and leads to the production of anti-cyclic citrullinated peptide antibody and other self-reacting immunological effector cells.

These factors then recruit the effector limb of the body's defense forces including humoral as well as cellular factors that lead to inflammation in the synovium causing formation of invading 'pannus' that starts to destroy the joint. Finally the joints become deformed with loss of joint functions. The same autoimmune forces also cause damage and destruction of several additional extra-articular tissues especially the eyes, lacrimal and salivary glands, haemopoetic system, lungs, skin and subcutaneous tissue, blood vessels, bone (osteoporosis) etc. causing extensive generalised disease that is NOT localised to joint only. In addition, there is increased chance of infection and cancer because the immune system remains 'busy' in self killing and forgets its primary function namely, prevention of the body from infection and cancer.