Mobilization and collection of peripheral blood CD34(+) cells from patients with Fanconi anemia

A potential therapeutic option for patients with Fanconi anemia is collecti on of peripheral blood stem cells prior to the development of severe pancyt openia. These hematopoletic cells potentially could be infused when symptom atic bone marrow failure develops, as autologous rescue after chemotherapy in the event of leukemic transformation, or as targets for gene therapy. Ei ght patients with Fanconi anemia were mobilized with 10 mug/kg per day of g ranulocyte colony-stimulating factor (median, 10 +/- 4 days) to determine t he feasibility of collecting peripheral blood stem cells for future use. Si x patients achieved a peripheral blood CD34(+) count of greater than or equ al to6/muL and underwent apheresis. The collection goal was 2 x 10(6) CD34 cells/kg based on a predicted weight 5 years from the date of collection. A mean of 2.6 +/- 0.9 x 10(6) CD34(+) cells/kg of the weight at the time of collection were collected, which corresponded to 1.9 +/- 0.4 x 10(6) CD34( +) cells/kg of the target weight. The collections required a mean of 4 +/- 3 days (range, 2-8 days) of apheresis. Six of the 8 subjects had greater th an or equal to 1 x 10(6) CD34(+) cells/kg cryopreserved based on both actua l and target weights, and 4 subjects had greater than or equal to2 x 10(6) CD34(+) cells/kg cryopreserved based on the target weight. These results su ggest that some patients with Fanconi anemia can have adequate numbers of C D34(+) cells mobilized and collected from the peripheral blood prior to the onset of severe bone marrow failure, but they may require an extended mobi lization and multiple days of collection. (C) 2001 by The American Society of Hematology.