Stress lysis in childhood leukemia

Area of Science:

• Pediatric Oncology
• Hematology

Background:

• Children with acute lymphoblastic leukemia (ALL) often show a reduced white blood cell (WBC) count before chemotherapy.
• This phenomenon is frequently misattributed to allopurinol and hydration therapies.

Purpose of the Study:

• To investigate the cause of pre-chemotherapy WBC count decrease in newly diagnosed ALL patients.
• To determine if allopurinol or other interventions are responsible for the observed WBC drop.

Main Methods:

• Retrospective review of medical records for 20 children with newly diagnosed ALL.
• Analysis of WBC counts in the interval between referral evaluation and hospital admission, prior to allopurinol administration.

Main Results:

• 80% of patients exhibited a decrease in WBC count before chemotherapy.
• The median WBC decrease was 14,000/mm(3) within 24 hours.
• The observed decrease was statistically significant (P = 0.002).

Conclusions:

• The pre-chemotherapy WBC decrease in ALL is likely due to rapid lysis of leukemic cells.
• Stress-induced release of endogenous corticosteroids is the probable mechanism driving this phenomenon.