Do we know what causes Castleman disease?
The main feature of Castleman disease is an overgrowth of lymphocytes (immune cells) called B cells. The cause of Castleman disease (CD) is not known for sure, but doctors suspect it is related to problems with the way a person's immune system is working. Many people with CD have abnormally high blood levels of certain substances produced by immune system cells.
Some scientists believe that some cases of CD may be caused by the body making too much of a protein called interleukin-6 (IL-6). IL-6 normally helps regulate immune function. Too much IL-6 seems to cause lymphocytes to grow and divide too quickly. High levels of IL-6 are often seen in the multicentric form of CD. But it’s not clear what causes the high levels of IL-6.
A virus seems to be involved in at least some cases of CD. Human herpes virus type 8 (HHV-8) is found in the lymph node B cells of many people who are HIV-positive and have multicentric CD. This virus is also known as Kaposi sarcoma-related herpes virus (KSHV) because it has also been found in people with Kaposi sarcoma (a rare type of cancer). In fact, some people with CD also have Kaposi sarcoma. HHV-8 has also been shown to cause infected cells to make a form of IL-6.
Last Medical Review: 06/11/2012
Last Revised: 06/11/2012