Abstract
In order to assess the effect of Pegfilgrastim on the duration of neutropenia and clinical outcome of patients after autologous peripheral blood stem cell transplantation (PBSCT), we compared 20 consecutive patients with lymphoma or multiple myeloma receiving a single 6 mg dose of Pegfilgrastim on day 1 posttransplant to a historical control group of 60 patients receiving daily Filgrastim 5 μg/kg starting on day 1 posttransplant. There were 54 M and 26 F, 30 patients with lymphoma and 50 with myeloma, 26 in CR and 54 not in CR. Mean age was 55±10 yrs and 25 had already received a previous autologous transplant. The two groups were matched for disease and disease status, transplant number, age and sex. Cell dose infused tended to be higher in the Pegfilgrastim group (7.16±3.82 vs 10.03±6.25 x106 CD34+ cells/kg, p=0.0575). There were no differences (p>0.05) in time to 0.5 (8 vs 9 days) or 1 (9 vs 9 days) x109/L neutrophils; to 1 % reticulocytes (13 vs 15 days) or 9 (12 vs 14 days) or 10 (30 vs 25 days) g/dL Hb; to 20 (9 vs 9 days) or 100 (20 vs 31 days) x 109/L platelets. The number of days with fever (2.7±2.3 vs 2.3±2.4 days), incidence of infections (all infections; bacteremia; bacterial, fungal or viral infections; FUO), duration of antibiotic therapy (8.7±5.9 vs 8.4±5.9 days), RBC (1.1±1.6 vs 0.9±1.6) and platelet (1.0±1.7 vs 1.2±1.8) transfusions, and time to hospital discharge (14.5±5.3 vs 15.4±5.8 days) were similar in the Pegfilgrastim compared to the Filgrastim group. However, after initial hematopoietic recovery, several differences between the groups became apparent, with the group always showing higher counts compared to the Filgrastim group (p values <0.05 to <0.001). Neutrophils remained significantly higher in the Pegfilgrastim group between days 14–30, lymphocytes between days 56–90, monocytes between days 21–24, reticulocytes between days 17–42 and platelets between days 35–90, respectively. These differences had no impact on clinical outcome after day 30 due to the low incidence of infectious events after engraftment. We conclude that Pegfilgrastim administrated on day 1 posttransplant facilitates early hematopoietic reconstitution comparable to daily Filgrastim. However, despite a trend towards fewer CD34+ cells transplanted, the Pegfilgrastim group enjoyed higher trilineage cell counts for some time after initial engraftment. This should be further tested in prospective randomized trials.
High percentage of CD34-positive cells in autologous AML peripheral blood stem cell products reflects inadequate in vivo purging and low chemotherapeutic toxicity in a subgroup of patients with poor clinical outcome
