Work

3: Reduced Intensity (RI) aLlogeneic Cord Blood Hematopoietic Cell Transplantation (Allo-CBHCT) in Pediatric Patients with Malignant and Non-Malignant Diseases

Year: 2006

Type: article

Abstract: There is a significant amount of morbidity and mortality following myeloablative CBHCT (Gluckman et al, NEJM 1997). RI conditioning may reduce regimen-related mortality (RRM) and the late effects associated with myeloablative regimens without increasing the risk of graft failure in children and adolescents (Del Toro et al, BMT 2004). We report the results in 22 pediatric recipients, 6F:16M, median age 6.5 years (0.4-21 yrs). Twenty one received unrelated CBHCT, with HLA matching of 4/6 (n = 14), 5/6 (n = 5), 6/6 (n = 2); 1 sibling CBHCT (6/6). Seventeen had malignant [HD (5), NHL (2), NBL (4), AML (2), MDS(3), CML (1)], and 5 had non-malignant [β-thal (1), HLH (2), WAS (1), SCD (1)] diseases. RI conditioning was fludarabine-based (150-180 mg/m2) with busulfan (8 mg/kg) ± rabbit ATG (n = 17) and fludarabine ± cyclophosphamide ± etoposide+ATG (n = 5). GHVD prophylaxis: tacrolimus and MMF (Osunkwo et al, BBMT 2004). Median TNC count was 3.8 × 107/kg (0.92-10.82) and CD34 count was 2.2 × 105/kg (0.34-7.0). The median day to WBC engraftment was 19.5 (1-47) and to platelet engraftment was 40 (6-170) days. There were 6 primary graft failures (1 CML, 1 β-Thal, 2 HLH, 1 MDS, 1 AML).The probability of developing grade II-IV and III-IV aGVHD was 33.3% and 15%, respectively, and probability of chronic GVHD was 20%. The probability of 3-year overall OS in all patients was 63%. Despite a log less nucleated cells/kg with CB vs PB or BM HCT, the 3-yr OS in standard-risk malignancy patients was 90%. The 1-yr OS in poor-risk malignancy patients was 21%. In conclusion, RI Allo CBHCT may result in more rapid hematopoietic reconstitution while decreasing RRM compared to myeloablative CBHCT and may be associated with high mixed-donor chimerism. Patients with non-malignant diseases may require increased intensity of conditioning. Further follow-up is required to evaluate the long-term effects following RI Allo-CBHCT.

Source: Transplantation and Cellular Therapy

DOI: 10.1016/j.bbmt.2006.08.005