Abstract

The cellular and humoral components of the neutrophil chemotactic response were studied in 65 children with acute lymphoblastic leukaemia (ALL). An abnormality in both components was found during relapse. In remission the cellular component only was affected. Although less obvious than during relapse the abnormality persisted while all cytotoxic therapy was given, returning to normal several weeks after treatment had been stopped. The absence of significant infection in relapse in this series could be due to the fact that a remisison was achieved within 3 weeks in all patients. However, a positive correlation between the migration index and incidence of bacterial infection during remission stressed the importance of impaired neutrophil chemotaxis in ALL.