Leukapheresis is a procedure to separate and collect white blood cells from the blood.

When there are too many leukemic cells in the blood, it can cause problems with normal circulation and can crowd out healthy cells. While chemotherapy is the standard treatment for leukemia and can help reduce the number of leukemic cells, it can take several days after the first treatment for this effect to occur. Leukapheresis may be used as a temporary treatment prior to chemotherapy to lower the number of leukemic cells.