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

A potential therapeutic option for patients with Fanconi anemia is collection of peripheral blood stem cells prior to the development of severe pancytopenia. These hematopoletic cells potentially could be infused when symptomatic bone marrow failure develops, as autologous rescue after chemotherapy in the event of leukemic transformation, or as targets for gene therapy. Eight patients with Fanconi anemia were mobilized with 10 mug/kg per day of granulocyte colony-stimulating factor (median, 10 +/- 4 days) to determine the feasibility of collecting peripheral blood stem cells for future use. Six patients achieved a peripheral blood CD34(+) count of greater than or equal 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 than or equal to 1 x 10(6) CD34(+) cells/kg cryopreserved based on both actual 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 suggest that some patients with Fanconi anemia can have adequate numbers of CD34(+) cells mobilized and collected from the peripheral blood prior to the onset of severe bone marrow failure, but they may require an extended mobilization and multiple days of collection. (C) 2001 by The American Society of Hematology.