The process of removing a specific component from blood temporarily. Also known as hemapheresis and pheresis. Forms of apheresis include plasmapheresis, harvesting plasma or liquid part of the blood; leukapheresis, harvesting leuko- cytes or white blood cells; granulocytapheresis, har- vesting granulocytes; lymphocytapheresis, harvesting lymphocytes; lymphoplasmapheresis, harvesting lymphocytes and plasma; and platelet- pheresis, harvesting platelets.