We have studied the feasibility of performing haploidentical stem cell transplants in 26 patients aged 1-54 (median 32) using CD34+ cell selection by the Cellpro device which gives approximately 2 logs of T-cell depletion. All patients (pts) received additional acute GVHD prophylaxis with cyclosporin A plus antithymocyte globulin (ATG, Thymoglobulin) 4.5mg/kg (6mg/kg if <30kg) over 3 days pretransplant. The cytoreductive regimens largely included cyclophosphamide 180mg/kg with either thiotepa 15mg/kg and 500cGy TBI (6 pts) or fludarabine 250mg/m5 and TBI 1200cGy (12 pts) with other combinations in the remaining 8. Donors were mismatched by 2 or more A, B and DR antigens. All patients had high-risk disease, 15 AML +/- MDS, 3 ALL, 2 NHL, 2 CML, 2 malignant histiocytosis and one CLL. Median dose of CD 34+ cells was 3.8 x 10"/kg (range 0.4 - 25), of CD3+ cells 8 x 105/kg (range 1 - 220). Of 23 evaluable patients, 5 failed to engraft granulocytes, 2 with persistent disease, 3 attributable to primary graft failure. Six additional pts evaluable for platelet engraftment failed to recover platelets, 2 with viral infection, one multiorgan failure, one persistent disease, one GVHD and one HUS. Of 21 evaluable pts 2 developed grade II and 2 grade III GVHD and 4 patients experienced chronic GVHD. Opportunistic infection contributed to death in 10 patients. There was one fatal case of PTLD in a pt with chronic GVHD. Three pts survive at 39, 40 and 58 months. Actuarial 3 year DPS for leukemic pts <35 years old is 30%. Haploidentical transplants are feasible, at least in younger pts, with partial T-depletion and additional immunosuppresion. This regimen results in no more acute GVHD than unmanipulated transplants from matched donors. Immune reconstitution remains a major challenge but early PTLD was not observed.
|Original language||English (US)|
|Issue number||11 PART II|
|State||Published - 2000|
ASJC Scopus subject areas
- Cell Biology