Researchers have demonstrated that high-dose granulocyte colony stimulating factor (HD-GCSF) mobilization in adult donors with sickle cell disease trait (SCDT) undergoing peripheral blood stem cell (PBSC) collection for familial haploidentical (FHI) stem cell transplantations appears to be safe and well tolerated.

The findings were presented in a poster at the 2022 Tandem Meetings. “Little is known about the safety and efficacy of [HD-GCSF] in adults with SCDT,” the researchers wrote in their abstract.

They hypothesized that HD-GCSF mobilization, followed by CD34+ enrichment with fixed mononuclear cell (CD3+ T-cell) add-back, would be safe and effective in donors with SCDT for PBSC FHI stem cell transplantations ( Identifier: NCT01461837).

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The researchers administered donors subcutaneous injections of GCSF 15mcg/kg/day for 4 days. Beginning on day 5, they performed daily peripheral blood leukapheresis with CD34+ cell enrichment and CD3+ T-cell add-back until the target cryopreserved cell doses were achieved (a minimum of 10 × 106 CD34 cells/kg and 2 × 105 CD3 cells/kg). The team also documented self-reported side effects experienced by donors.

A total of 18 donors with SCDT (83% female and 17% male), who were 31-50 years of age, underwent HD-GCSF mobilization followed by leukapheresis and CD34+ cell enrichment with CD3+ T-cell add-back. The median number of collections per donor was 2 (range, 1-5).

The target number of enriched CD34+ cells for infusion was achieved from 72% of donors. Among the 5 donors for whom the collections did not yield the target cell doses, the counts were between 7.37 and 9.78 × 106 CD34+ cells/kg after 1 to 5 collections.

Following the collections, engraftment was achieved in 100% of haploidentical SCD recipients. The researchers observed rapid myeloid engraftment, with a median of 9 days, and no graft failures.

Self-reported donor side effects secondary to HD-GCSF mobilization included grade 1 bone pain (n=11; 61%), grade 1 nausea (n=3; 16%), grade 1 headache (n=2; 11%), grade 1 fatigue (n=2; 11%), grade 1 abdominal pain (n=2; 11%), grade 1 dizziness (n=1; 5%), grade 1 general pain (n=1; 5%), grade 3 thrombocytopenia (n=1; 5%), and grade 3 bone pain (n=1; 5%).

“This study demonstrates that HD-GCSF mobilization in adult FHI stem cell donors with SCDT undergoing PBSC collection is safe and well-tolerated,” the researchers concluded. “PBSC collection and CD34+ cell enrichment resulted in 100% haploidentical SCD recipient engraftment.”

Read more of Hematology Advisor’s coverage of the 2022 Tandem Meetings by visiting the conference page.


Milner J, Flower A, Schulman S, et al. Safety and efficacy of high dose granulocyte colony stimulating factor mobilization in familial haploidentical adult donors with sickle cell trait followed by CD34+ cell enrichment and mononuclear cell add-back prior to haploidentical allogeneic transplant. Presented at: 2022 Tandem Meetings; April 23-26, 2022. Abstract 320.