Literature Summary
Major Literature
Ganzel et al, Blood Reviews 2012
Hyperleukocytosis = WBC >100,000
10-30% in ALL
Complications associated w/ hyperleukocytosis
Leukostasis
Increased blood viscosity and/or endothelial activation by blasts secrete cytokines that promote more blast recruitment --> vascular obstruction
CNS and lung most commonly affected
CNS: confusion, dizziness, HA, tinnitus, vision change, delirium, ataxia, somnolence, coma, ICH
Lung: SOB, tachypnea, hypoxemia, infiltrates
Other organs
Acute leg ischemia
Renal vein thrombosis
Priapism
In pediatric ALL, leukostasis most prevalent w/ WBC >400,000
TLS
Due to high cell turnover
HyperUA, hyperPhos, hyperK, hypoCa
DIC
Due to high cell turnover --> exposes endothelium to high levels of tissue factor --> triggers extrinsic coagulation pathway
Why treat?
To prevent above complications
Chemotherapy can further increase risk of above complications if WBC high
How do you treat?
Hydration
Allopurinol (chemical cytoreduction)
Leukapheresis (mechanical cytoreduction)
Indications
Reduce acute sxs from leukostasis
Prevent leukostasis
Avoid/Reduce severity of TLS and DIC
Efficacy
Single cycle can reduce WBC by 20-50%
Most authors suggest WBC <100,000 as the goal
May reduce early death (mortality in the first 2 weeks) but no effect on cancer remission rates or overall survival
Complications
HypoCa from citrate toxicity
RBC or platelet loss during the procedure
Venous access complications (bleed, infection, thrombosis)