Long Term Survival in Refractory Leukemia Patient Treated with Related HLA Haploidentical Stem Cell Transplantation

Objective: To assess the long term survival of patients with refractory leukemia treated by HLA haploidentical stem cell transplantation.

Methods To analysis the outcomes of 48 cases patients with refractory leukemia underwent HLA haploidentical stem cell transplantations from August, 1998 to May, 2008. The median age was 16 years old (7–52 years old). Patients received stem cells from their parants, daughter, son, and sibling donors. Twelve patients received three HLA locus mismatched stem cells and twenty patients received two HLA locus mismatched donors stem cells. Sixteen patients were grafted one HLA mismatched donors stem cells. The conditioning regime consisted of fludara (25mg/m² × 5d), busulfan (4mg/kg × 4d) and cyclophosphamide (60mg/kg × 2d). Median dose of rabbit anti-human lymphocyte globulin (5mg/kg × 5d) was added. CSA combined with short course of MTX were used for prophylaxis GVHD. A median dose of 6.0 × 10⁸/kg(3–9 ×10⁸/kg) mono-nucleated cells was grafted. The mean CD34⁺ cells number was 5.5 × 10⁶/kg (3–6.5 × 10⁶/kg)

Results Forty-seven patients were successfully to be engraftment and one failed to be engraftment. The median time of white cells and platelet reconstitution was 14 days (11–20 days) and 18 days (14–20) respectively. Severe acute graft versus host disease occurred in seven patients, and six died. Seven patients suffered from intensive chronic graft versus host disease and four died with fungus infection. Seven patients relapsed and died. The median relapse time was 6 months (3 months to 24 months). Three patients died from severe diarrhea with CMV infection. Four patients died from intensive chronic graft versus host disease. Twenty patients are still survival and disease free with high karnofsky performance scores. The disease free survival is 45 percent as follow up 3 years (1 to 7 years).

Conclusion: HLA haploidentical peripheral blood stem cell transplantation may be an effect therapy to refractory leukemia. And some refractory leukemia patients could benefit from HLA haploidentical peripheral blood stem cell transplantation.