Toxicities associated with stem cell mobilization utilizing cyclophosphamide and growth factor versus G-CSF alone in primary systemic amyloidosis

Background: Autologous peripheral blood stem cell transplantation (PBSCT) is increasingly being utilized for primary systemic amyloidosis (AL amyloid). Various mobilization regimens have been used at different centers. Methods and Materials: We retrospectively reviewed the medical records of 46 patients who underwent stem cf 11 mobilization in anticipation of PBSCT for primary systemic amyloidosis between February, 1996, and April, 2000. Twenty-seven patients were mobilized with a combination rf cyclophosphamide and either GM-CSF or G-CSF (CTX group), nineteen patients we re mobilized with G-CSF alone (OF group). Results: Median age was 51 years for the CTX group (range 35 to 69) versus 54 years for the OF group (range 40 to 64). Ninety-three and forty-one percent of patients in the CTX group experienced neutropenia (ANC<1 X 10<:9 per liter) or thrombocytopenia (platelets< 50 X 10e9 per liter) respectively. Nausea, vomiting and diarrhea were noted more often in the CTX group (81%, 59% and 41%, respectively) relative to the GF group (11%, 5% and 5%, respectively). Orthostatic symptoms were observed only in the CTX group (37%). Shortness of breath and eder la were more frequent in the CTX group (30% and 44%, respectively) than in the GF groi ip (21% each). Hospitalizations occurred in the CTX group 28% of the time versus 16% in the GF group. Temperature 101.5°F was observed only in the CTX group (19%). Oie patient in the CTX group experienced a gastrointestinal bleed and subsequent pulmonary embolus. One patient in the GF group had fatal pulmonary edema. Stem cell mobilizati m yielded a median CD34+cells/kg of 12.74 x 10e6 for the CTX group (range 2.62 to 50. )3 x 10e6) versus 5.26 x 10e6 for the GF group (range 2.01 to 22.40 x 10e6). Conclusion: Cyclophosphamide plus growth factor appears to be associated with more toxicities compared to G-CSF alone in stem cell mobilization for AL amyloid; however, a prospective trial would be required to confirm these findings.