Background: Patients with acute myeloid leukemia (AML) with hyperleukocytosis of at least 100 x 10(9) per L are at high risk of early death due to pulmonary or cerebral leukostasis. Although the efficacy of leukapheresis in terms of prompt cytoreduction is generally accepted, published data regarding the clinical value of immediate therapeutic leukapheresis are limited and conflicting.
Study design and methods: To determine whether leukapheresis has a favorable impact on early mortality, the clinical course of 53 newly diagnosed patients with AML and hyperleukocytosis admitted between 1995 and 2005 was analyzed retrospectively. Before August 2001, 28 patients received chemotherapy without leukoreduction (Cohort A). Thereafter, all AML patients with hyperleukocytosis were scheduled to receive leukapheresis, which was performed in 25 patients (Cohort B).
Results: There were no procedure-related adverse events. By Day 21 of therapy, 13 of 53 patients had died, resulting in an overall early death rate of 25 percent. In a multivariate logistic regression model, patients in Cohort B had a significantly lower risk of early death than patients in Cohort A (16% vs. 32%, respectively; p = 0.015). Dyspnea (p = 0.005), elevated creatinine (p = 0.028), and higher lactate dehydrogenase serum levels (p = 0.021) were independent risk factors for early death. With a median follow-up of 24.2 months, the overall survival was similar in both cohorts (Cohort A, 7.5; Cohort B, 6.5 months). Thus, leukapheresis had no impact on patients' long-term survivals.
Conclusions: Our experience suggests that AML patients with hyperleukocytosis receiving leukapheresis had a significantly lower risk for early death by Day 21 than patients treated without leukapheresis. We therefore have adopted leukapheresis as a standard procedure in our department.