In efforts to find better treatments, scientists are seeking a better understanding of the complex set of diseases known as arthritis. To do that, many researchers are studying functions of the basic cells and processes that keep the human body in good working order.

Some forms of arthritis are believed to be caused by a defect in the body’s immune system. When the immune system works correctly the body is able to recognize antigens as foreign invaders (such as viruses and bacteria) and fight them off with inflammation. When the system is defective, in addition to recognizing and fighting off the antigens, the body’s defender cells may also attack normal body tissues, causing damage and pain. This knowledge has led researchers to one possible course of action. Understanding how the immune mechanism works will help you understand what they are trying to do.

Soon after an antigen enters the body it meets the recognition cells of the immune system. The monocyte is a cell that transforms the antigen so that it can be identified by the lymphocyte. Lymphocytes distinguish between normal substances in the body and those that are foreign. There are two types of lymphocytes: T and B-lymphocytes. When they work properly, B-lymphocytes change into larger cells known as plasma cells, which manufacture antibodies that attach themselves to the antigen and form a complex.

Complements a series of blood proteins, is activated by this complex. To finish the job of killing off the antigen the activated complement attracts cells called phagocytes. Phagocytes engulf the complex, and their enzymes work to “digest” and destroy the complex. T may directly attack and destroy and antigen and also produce substances that stimulate or suppress other lymphocytes.

Researchers know that the lymphocytes in individuals with rheumatoid arthritis behave differently from normal lymphocytes. Research efforts have demonstrated that some patients with rheumatoid arthritis improve temporarily when large numbers of these lymphocytes are removed from their blood. Because of this knowledge, researchers hope to develop a more direct treatment against the defective lymphocytes.