Transient neutropenia in normal donors after G-CSF mobilization and stem cell apheresis

Thirteen normal adult donors underwent daily leukapheresis for peripheral blood progenitor cell collection for allografting beginning on day 4 or 5 of G-CSF mobilization (12 μg/kg/d). They had complete blood counts performed 7–10 d after the completion of the procedure. A reduction in the total leucocyte count below baseline levels, accounted for by a decrease in the absolute neutrophil (ANC) and lymphocyte counts, was noted. Neutropenia (ANC < 1.5 × 10⁹/l) occurred in two (15%) of the donors. The lowest ANC observed was 0.6 × 10⁹/l. The neutropenia was asymptomatic and resolved on follow-up evaluation.