Many HLA antigens exist, but some are of special interest because they are more common in certain autoimmune diseases . HLA antigens are also measured to determine relationships between children and parents when such relationships are in question. Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others. A photomicrograph of bone tissue.
Bone tissue is obtained from a bone biopsy and examined under a microscope.
This is a picture of how normal tissue appears when magnified.