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)