Beta-thalassaemia major: bone marrow versus peripheral blood stem cell transplantation

To compare PBSCT with BMT in Thalassaemia patients in terms of rejection, non-rejection mortality, disease free survival and overall survival.

Fifty six patients were transplanted from September 2000 - July 2005. Twenty nine underwent BMT and 27 received PBSCT. Most patients were intensely transfused to keep minimum haemoglobin of 12 gm/dl and received desferioxamine, 24 hours infusion, before transplantation. Pesaro class I (n-20) and class II (n-20) received conditioning with standard Bu/Cy. Of class III (n-16), ALG was added to standard Bu/Cy in 9 who received PBSCT and 7, who received BM, were conditioned with Hydrea 20-30 mg / kg (day - 45 to -11), Azathioprin 2-3 mg / kg (day - 45 to day -11), Fludarabine 25 mg / kg (day -17 to -13) followed by Bu14 / Cy 200 started on day - 10. Triple immunosuppression was used for whole PBSC group and class III-BM group. For others, a GvHD prophylaxis comprised of MTX and cyclosporine only. MNC dose infused was > 4 x 10(8)/kg (range 4.8-8.2) recipient weight in PBSC patients and for BM its range was 1.6 - 5.2 MNC / kg. All patients received G-CSF 5mg / kg / day, from day + 5, till ANC > 0.5 x 109 / I. Median age of the donor was 8.6 years. All recipients and donors were genotypically HLA matched except in one. PBSC were harvested on day 5 of G-CSF administration. Follow up ranged from 273 - 2088 days.

Median age for BM and PBSC group was 5.2 and 6.9 years. Engraftment was achieved in all cases. Median time to ANC of 0.5 x 10(9)/ I in BMT / PBSCT patients was 13 / 10 days (range 11-19 / 9 - 15) and for platelets of 20 x 10(9) / I it was 17 / 14 days (range 14 - 28 / 12 - 19). aGvHD (grade II - IV) was seen in 30% / 26% cases in BMT / PBSCT group. Incidence and severity of chronic GvHD was not statistically different in two groups (BM-24% & PBSC -30%). Six patients rejected the graft. Of the four who rejected the graft from class III, 3 were from PBSC group. DFS in risk classes of the two groups was not significant. Overall survival / disease free survival for the BM and PBSC group as on December 2005 was 73% / 65% and 67% / 55%.

This study shows that major outcomes with PBSCT are not statistically different from BMT. Rejection and disease free survival in class 3 patients who received intensified immuno-suppression and large doses of PBSC is comparable to BM group who were conditioned according to newer Lucrali protocol.