Sunday, April 19, 2015

Pathophysiology of Rheumatoid Arthritis... or my best try at it

The pathophysiology of rheumatoid arthritis is complicated so I will make this as simple and clear as possible.

The cause of rheumatoid arthritis is still unknown, but there are a few things that we do know. There are both genetic and environmental components. A widely accepted theory says that it begins with a reaction to an antigen, which is known as a trigger. What the antigen is remains unknown, and the best we have in terms of research is identifying some risk factors for RA. Here are a few of the research findings:


  • Women who take oral contraceptives have a lower risk of RA compared to those who never took them or those who previously took them
  • Viral infections are a potential trigger (Epstein-Barr, parvovirus)
  • Bacterial infections (Proteus and Mycoplasma)
  • Heat-shock


The immune response causes formation of an antibody called IgG. The body responds with autoantibodies against IgG, and these are called rheumatoid factor (RF). Then, RF plus IgG form complexes, and these deposit in the body. One place they deposit is in synovial membranes, leading to an inflammatory response. Lots goes on during an inflammatory response (refer to VIDEO), and portions of it are very harmful. The disease passes through 4 stages, listed in the table below.

Lewis, Heitkemper. Medical-Surgical Nursing, 8th Edition. 



Additionally, here are some pictures of damage to joints from RA.

Lewis, Heitkemper. Medical-Surgical Nursing, 8th Edition. 



The beginning of the disease process is not very obvious. Arthritic complaints will come after symptoms like fatigue, anorexia, weight loss and generalized stiffness. Joint manifestations include pain, stiffness, limitation of movement, and signs of inflammation. What is special to RA compared to osteoarthritis is that the joint problems will occur bilaterally, or on both sides of the body, and start with small joints in the hands and feet (though other larger joints may also be involved). Joints become more and more painful, tender, especially with movement. Eventually there will be deformity of joints, leading to disability.


 Resources:
1. Lewis, Heitkemper. Medical-Surgical Nursing, 8th Edition. 

2. Overview of Epidemiology, Pathophysiology, and Diagnosis of Rheumatoid Arthritis - See more at: http://www.ajmc.com/publications/supplement/2012/ace006_12dec_ra/ace006_12dec_gibofsky_s295to302/1#sthash.SeynEPpq.dpuf

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