A protein made by plasma cells (a type of white blood cell) in response to an antigen (a substance that causes the body to make a specific immune response).
Arthralgia literally means joint pain; it is a symptom of injury, infection, illnesses (in particular arthritis) or an allergic reaction to medication.
A rare, inherited, progressive, degenerative disease of childhood that causes loss of muscle control, a weakened immune system, and an increased risk of cancer.
For learning, not diagnosis. This glossary provides general educational information and is not a substitute for advice from a qualified healthcare professional. If you may be experiencing a medical emergency, contact local emergency services.