Peripheral Blood Stem Cell Transplantation in Children with Thalassemia.

Although improvements in conventional treatment have enhanced the prognosis of thalassaemia, stem cell transplantation remains the only cure. Studies have shown that peripheral blood stem cell transplantation (PBSCT) results in rapid hematological and immunological recovery but increased risk for graft versus host disease (GVHD). We report the PBSCT experience of Akdeniz University School of Medicine Pediatric Hematology&Oncology department concerning 54 patients with beta-thalessemia. Median age was 6 years (1–18 years), 26 were girls, 28 were boys. Thirteen were Class I, twenty-two were Class II, nineteen were Class III according to Pesaro criteria. 12 patients were given BU+CY and 39 BU+CY plus ATG as conditioning regimen. Three Class III patients were conditioned with Pesaro protocol 26. BU dosage was 16 mg/kg for Class I and Class II patients followed by CY 200 mg/kg totally. Class III patients received 14 mg/kg BU and 160 mg/kg CY. All patients received MTX (+1, +3, +6) and CsA for GVHD prophylaxis. All of the donors were HLA identical (51 sibling, 3 parents). Median age of the donors was 7 years (range: 2–40 years). G-CSF was given for 5 days with the dosage of 5 μgr/kg/day to child and 10 μgr/kg/day to adult donors for peripheral blood stem cell mobilization. Stem cell apheresis was performed on fifth day, but continued to day 7 if adequate cell count was not achieved. In older children and parents if appropriate, antecubital veins were used for harvesting but for younger donors, femoral dual lumen catheters were emplaced. Fresenius AS. TEC204 or Haemonetics MCS+ cell separators were used for apheresis. The median apheresis count was 1 (range 1–3). Median transfused MNC and CD34 cell counts were 10.1×10⁸/kg (range:5.3–27.7×10⁸/kg) and 4,65×10⁶/kg (range:1.1–29.4×10⁶ /kg) respectively. Median neutrophil and platelet engraftment times were day 14 and day 15, respectively. Grade II–IV acute GVHD were observed in five patients, chronic GVHD were in four of two were extensive. One patient died on posttransplant day 32 because of acute GVHD. Death because of chronic GVHD was not observed. At a median follow-up of 26 months (1–92 months), overall survival for the whole group is 92.6 % and evet-free survival is %80.4. Autologous reconstitution developed in six patients and graft failure in two.