<<Disclaimer: Verify this information before applying it to your situation.>> Hellos again. I'd like to give some information about HLA so that everyone will have a better understanding of it, as it's not a subject that most people are aware of. HLA stands for Human Leukocyte Antigen ans these factors were first found on white cells or leukocytes. HLA antigens are glycoproteins (a combination of proteins and sugars) that are found on every nucleated cell in the body. Mature red blood cells are the only cells that lack HLA antigens as they do not have a nucleus. The HLA antigens are involved in immune regulation. Basicly, your HLA type can be called your body type just as your particular ABO type is your blood type. Because of these HLA markers, your body is able to distinguish between what is from your body and what is not. HLA typing is done using leukocytes as it is a lot easier to take a sample of blood and extract the leukocytes than it so to take a peice of tissue and prepare it for the test. The problem with the change in nomenclature occurs because this field is still developing. The first attempt to standardize HLA nomenclature occurred in 1967. Every so often, the WHO Terminology Committee meets to decide how the nomenclature should be listed. The "w" in some types stands for workshop,meaning that this designation is tenative upon review of future data. So, the results of HLA typing simply shows what HLA factors you have inheritied from your parents. In no way can this information be used to predict whether or not you will get a certain disease, even though it has been shown that there are definite associations between certain HLA types and diseases. The only reason one should go through HLA typing is if they need a bone marrow transplant or they may be a bone marrow donor, as HLA typing is extremely important for the success of a bone marrow transplant. I can't imagine how it would help someone to make the diagnosis of CD when there are more specific ways to determine that. In the case of someone who has a family history of CD, perhaps HLA typing would be useful to warn them of their possibility of CD. Hope this is helpful. Ellen Eagan South San Francisco, CA [log in to unmask]