G-CSF stimulated BM (G-BM) offers a source of stem cells that has been reported to be associated with faster engraftment and decreased risk of GVHD. It is possible that these differences are related to the immunological composition of these grafts. We compared G-BM and unprimed bone marrow as a source of stem cells in 33 consecutive thalassaemia major patients who underwent a matched related allogeneic SCT treated with a similar conditioning and GVHD prophylaxis regimen. Twenty patients received G-BM from HLA matched donors primed with G-CSF 10ug/Kg/day for 2 days prior to BM harvest and the rest received unprimed BM. Lymphocyte subsets and progenitor cells contained in the grafts was assessed using FACSCalibur and monoclonal antibodies directed against B, NK and T cell subsets. The median age of the cohort was 7 years (range: 2–14) and there were 22 (67%) males. All patients received Bu/Cy/ATG as conditioning regimen. Cyclosporine and short course Methotrexate were used as GVHD prophylaxis. 88% of patients achieved sustained engraftment. The mean follow up was 37 months. Patient and graft characteristics were similar in both HSC sources (Table 1). The target cell dose of 3x108 TNC/Kg could be achieved with smaller volume of the graft in the G-BM group. Time to neutrophil engraftment (median: 16 days, p= 0.260) and platelet engraftment (median: 30 Vs 26 days, p= 0.163) was identical in both the groups. The incidence of acute GVHD (grade II–IV, 10% vs. 15%) and chronic GVHD (12% vs. 9%) were similar in both the groups. 9 patients rejected their graft, six (30%) in G-BM and three (23%) in BM. There were 4 transplant-related deaths within the first 100 days (two in each group). Survival curve analysis showed no difference in overall and event free survival between the two groups. In this cohort of patients, G-BM resulted in rates of engraftment, GVHD, rejection and TRM that were similar to those produced by unprimed BM. G-BM as a HSC source may not add selective advantage to patients with thalassaemia major undergoing a matched related allogeneic SCT.

Comparison of Graft Source

CharacteristicsBM (n=13)G-BM (n=20)P
Age (median years: range) 6 (2–14) 8 (2–13) 0.22 
Male (%) 9 (69) 13 (65) 1.00 
Lucarelli Class III (%) 5 (39) 9 (45) 0.71 
Harvest TNC/mm3 23430±9007 39045±13457 0.000 
Harvest Volume 417±173 290±98 0.012 
TNC / 10e8/kg 4 (2.9–7.6) 4.8 (2.4–8.8) 0.083 
CD34 x 10e6/kg 6.89 (3.3–12.9) 8.3 (1.2–16.4) 0.439 
Total CD3 cells x 10e6/kg 45.6 (12.7–120.1) 40.4 (26.2 – 139.8) 0.912 
NK cells x 10e6/kg 4.71 (0.9–49.8) 6.7 (0.1–15.2) 0.580 
Total B cells x 10e6/kg 19 (0.3 – 47.2) 24.3 (0.8 – 62.2) 0.32 
Helper T cells x 10e6/kg 20.8 (7.2 – 48.7) 13.7 (15.4 – 77.8) 0.556 
Cytotoxic T cells x 10e6/kg 24.8 (7 – 91) 10.6 (8.8 – 51.2) 0.39 
CharacteristicsBM (n=13)G-BM (n=20)P
Age (median years: range) 6 (2–14) 8 (2–13) 0.22 
Male (%) 9 (69) 13 (65) 1.00 
Lucarelli Class III (%) 5 (39) 9 (45) 0.71 
Harvest TNC/mm3 23430±9007 39045±13457 0.000 
Harvest Volume 417±173 290±98 0.012 
TNC / 10e8/kg 4 (2.9–7.6) 4.8 (2.4–8.8) 0.083 
CD34 x 10e6/kg 6.89 (3.3–12.9) 8.3 (1.2–16.4) 0.439 
Total CD3 cells x 10e6/kg 45.6 (12.7–120.1) 40.4 (26.2 – 139.8) 0.912 
NK cells x 10e6/kg 4.71 (0.9–49.8) 6.7 (0.1–15.2) 0.580 
Total B cells x 10e6/kg 19 (0.3 – 47.2) 24.3 (0.8 – 62.2) 0.32 
Helper T cells x 10e6/kg 20.8 (7.2 – 48.7) 13.7 (15.4 – 77.8) 0.556 
Cytotoxic T cells x 10e6/kg 24.8 (7 – 91) 10.6 (8.8 – 51.2) 0.39 

Author notes

Disclosure: No relevant conflicts of interest to declare.

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