Acute lymphoblastic leukemia with aleukemic prodrome: preleukemic dynamics and possible mechanisms of immunosurveillance
Abstract
The development of acute lymphoblastic leukemia (ALL) typically involves the acquisition of at least two genetic events. The initial mutation leads to the formation of a persistent, but clinically covert, preleukemic clone.
Additional genetic changes then lead, in a stepwise manner, to complete leukemic transformation and promote the clinical onset of the disease.We analyzed eight children with B-cell precursor ALL who had a prodromal period of atypical anemia along with fatigue and infections GREATER-THAN OR EQUAL TO6 weeks before the clinical diagnosis of leukemia (Table 1). As a hematologic disorder was suspected, BM aspirates were investigated by morphology and flow cytometry.
Initially, the diagnostic criteria of ALL were not fulfilled and thus no antileukemic treatment was started except for low doses of corticosteroids in three patients. However, continuous follow-up was indicated and after a premalignant period lasting from 42 days up to 17 months the diagnostic criteria were met and the diagnosis of B-cell precursor ALL was finally confirmed in all eight patients.
Using a combination of several strategies we tried to backtrack leukemia-specific markers and retrospectively follow the kinetics of the (pre)leukemic cells before the clinical manifestation of ALL in these patients.