No one has discovered the cause of this disease, but many doctors suspect a virus is involved. Doctors have found a virus called human herpes virus type 8 (HHV-8) in many people with multicentric Castleman disease (CD). This virus is also known as Kaposi sarcoma--related herpes virus (KSHV), because it has also been found in people with Kaposi sarcoma (formerly called Kaposi's sarcoma). In fact, some people with CD also have Kaposi sarcoma.

Doctors suspect that problems with the way a patient's immune system is working may contribute to development of CD. Many people with CD have abnormally high blood levels of certain substances produced by immune system cells.

Some scientists believe that CD occurs when there is too much of a protein called interleukin-6 (IL-6). IL-6 is a protein the body makes to help regulate immune function. Too much IL-6 seems to cause lymphocytes to reproduce excessively. High levels of IL-6 are seen in CD, and tend to be associated most often with multicentric disease. There is a link between HHV-8 and IL-6.

Last Medical Review: 08/03/2009
Last Revised: 08/03/2009