Therapeutic leukapheresis involves removal of white blood cells in patients with acute or chronic leukemia.
Hyperleukocytosis is defined as a white blood cell count greater than 100,000 per µL. Very high white blood cell counts can result in leukostasis in the microvasculature. Patients with an excess of myeloid or monocytoid cells tend to be become symptomatic sooner than with an excess of lymphocytes since they tend to aggregate.
Leukemias requiring leukapheresis: AML, CML, ALL, CLL
Complications of leukocytosis:
(1) leukostasis and hyperviscosity, which may result in renal, pulmonary and CNS dysfunction
(2) tumor lysis syndrome, hyperuricemia and electrolyte abnormalities
(3) diffuse intravascular coagulation (DIC)
(4) expansion of the intravascular blood volume
Leukapheresis alone provides only temporary relief. It has to be performed in conjunction with pharmacotherapy (hydroxyurea, chemotherapy).
collection efficiency in percent =
= (WBC count of collected product per µL) * (volume of product in mL) / ((white blood cell count in peripheral blood per µL) * (total blood volume in mL)) * 100%
where:
• Since there is an expansion of blood volume the standard equations for total blood volume may not be accurate.
Complications of leukapheresis:
(1) thrombocytopenia
(2) problems of vascular access
