Post Graduate Institute of Child Health (PGICH), Noida, India Delhi, Delhi, India
Background/Case Studies: There is been a growing interest in using Plerixafor for mobilising hematopoietic stem cells (HSC) in sickle cell patients as despite the relative safety of administration of G-CSF in most individuals, including subjects with sickle cell trait, severe and life-threatening complications have been reported when used in individuals with sickle cell disease (SCD). Additionally compared to G-CSF, plerixafor as a single agent mobilizes a more primitive subset of CD34+ cells, including long-term repopulating HSC. There is limited data on the use of plerixafor for mobilising these special groups of patients as well as peripheral HSC harvest.
Study
Design/Methods: We analysed retrospective data on the autologous harvest of sickle cell patients from whom autologous stem cells were collected for salvage transplant in case of rejection as all were planned to undergo Haploidentical Allogeneic HSCTs. Harvest was done after informed consent and the product was cryopreserved for possible use in future.
Results/Findings: Between March and May 2023, four (4) sickle cell disease patients of African descent (mean age 16±6.9 years; 3 females and one male) consented to the plerixafor-based mobilization (240 mg/kg); 4 hours before the harvest) and autologous harvest. The mean weight was 49.9±21.1 Kg and the mean height was 152.2±24.8 cm. The mean pre-mobilization hemoglobin was 10.6±0.64 gm/dl; HbF was 15.5±8.8%; HbA0(non-glycated) was 13.3±18.8; HbA2 was 2.8±0.355; S window was 63.8±18.8 and platelets counts were 557±177x103/µL. Post mobilization (pre-harvest) the mean total WBC was 26.7±7.4 x103/µL; hematocrit 27.1±1.3%, platelets were 429±178 x103/µL, mononuclear cell counts of 9.8±4.7 x103/µL and pre-CD34+ was 29.5±18.5 x103/µL. All harvests were done on the Optia (Terumo BCT) platform with a mean of 2.9±1.1 times the total blood volumes processed with a mean of 973±172 ml of ACD being used and harvested in 235±97 minutes. The mean product volume collected was 235±88 ml with mean total WBC 255±121 x103/µL, mean product hematocrit 2.5±0.7% and mean platelets 1783±909 x103/µL. Out of 4 patients, there was one poor mobilization and collection failure (dose collected less than 2 x106/kg). The overall mean mononuclear cells collected were 9.1±5 x108/kg and the mean CD34+ dose collected was of 2.7±1.73 x106/kg. There were no adverse events reported during the harvest. During the harvest, care was taken to avoid hypoxia or hypothermia in order to avoid a sickling crisis. Conclusions: This is one of the first case series of plerixafor-based mobilization and peripheral blood harvest of hematopoietic stem cells in sickle cell disease patients from India. None of the patients reported any adverse event with regard to the mobilization and harvest showing the safety profile of this mobilization strategy. There is still a need for more studies and data from our region to adopt this as a standard mobilization protocol.
Importance of research: This is one of the first data on plerixafor only based mobilization for hematopoietic stem cell collection in sickle patients in india
