bone, joint, and muscle disorders
IgG4 Related Disease
Introduction
Immunoglobulin G4-related disease (IgG4-RD) is an uncommon immune disorder that usually affects multiple tissues and organs with tumor-like masses and/or painless enlargement. Symptoms depend on which organs are affected. Most people with IgG4-RD are middle-aged to older men, but the disorder can affect people of any age and sex. The exact cause of IgG4-RD is unknown, but it likely involves a problem with the Overview of the Immune System . IgG4-RD can damage organs before people notice symptoms and seek medical care. Organ enlargement may cause concern about a cancer until the diagnosis is made. Diagnosis generally requires biopsy. Treatment is with corticosteroids andrituximab, medications that modify the immune system's activity, and sometimes surgery. Immunoglobulins are Antibodies , which are proteins that are part of the body's IgG4 is the least common of the 4 subclasses of IgG. It has various normal functions in the body, but in IgG4-related disease, immune cells that produce IgG4, along with other related cells, accumulate abnormally in certain organs and damage them. The affected organs can enlarge and may eventually fill with scar tissue (fibrosis) and the damage can be permanent. One or more organs are affected. Other organs and tissues can be affected, but the 11 organs considered typical of IgG4-RD include Pancreas (organ that secretes digestive juices and hormones such asinsulin) Bile ducts (small tubes that carry bile, a fluid that aids in digestion) Lacrimal (tear) glands Orbital tissues (tissues surrounding the eye) Salivary glands (glands that lie under the side of the jaw and behind the angle of the jaw) Lungs Kidneys Retroperitoneal tissues (at the back of the abdomen) Aorta (the main blood vessel bringing blood from the heart to the body) Meninges (layers of tissue that cover the brain and spinal cord) Thyroid gland (gland in the front of the neck that controls many body activities) 