Red Cell Half Life Determination in Patients With and Without Sickle Cell Disease

Background: Sickle cell disease (SCD) is an inherited blood disorder. It results from a single genetic change (mutation) in red blood cells (RBCs). RBCs are the cells that carry oxygen to the body. In people with SCD, some RBCs are abnormal and die early. This leaves a shortage of healthy RBCs. Researchers want to learn more about how long RBCs live in the human body. Objective: To study how long RBCs live in people with and without SCD. Eligibility: People age 18 and older who either have SCD, had SCD but were cured with a bone marrow transplant, have the sickle cell trait (SCT), or are a healthy volunteer without SCD or SCT Design: Participants will be screened with a medical history and physical exam. They will give a blood sample. Participants will have a small amount of blood drawn from a vein. In the laboratory, the blood will be mixed with a vitamin called biotin. Biotin sticks to the outside of RBCs without changing their function, shape, or overall lifetime. This process is known as biotin labeling of RBCs. The biotin labeled RBCs will be returned to the participant via vein injection. Participants will give frequent blood samples. Their RBCs will be studied to see how many biotin labeled RBCs remain over time. This shows how long the RBCs live. Participants will give blood samples until no biotin labeled RBCs can be detected. During the study visits, participants will report any major changes to their health. Participation lasts for up to 6 months.