14800-DvRappard

86 Chapter 5 function could not be immediately correlated. Especially the predictive validity of the BSID-II-NL for later cognitive function in terms of Wechsler IQs is poor and should therefore be interpreted with care. 5 MRI evolution: For all patients, brain magnetic resonance imaging (MRI) was available at the time of diagnosis. Transplanted patients underwent an MRI at 6 months after HCT, thereafter every 1 year or on indication. Axial T2-weighted images were scored using the MLD Loes score. 6 Statistical analyses Kaplan-Meier estimates were used to depict outcome probabilities for the main and other outcomes of interest. Descriptive statistics were used to describe primary and secondary endpoints, using SPSS version 22.0. HCT procedure All patients received amyeloablative conditioning regimenof busulfan (75 to 90mg*h/L) and antithymocyte globulin (ATG) (10 to 2.5 mg/kg/day, day -8 till -4) combined with either cyclofosfamide (200 mg/kg total) or fludarabine (160 mg/m2 or 40 mg/m2 from day -5 till -1). All patients received cyclosporine (target range 200–250 mg/L,) as Graft versus Host Disease (GvHD) prophylaxis. Prednisone was given to cord blood recipients from day 0 until day 28, 1 mg/kg per day, as well as methotrexate 10 mg/m2 at days +1, +3 and +6. The average total nucleated cell dose was 2.26 x 10 5 cells/kg, with a median of 2 x 10 5 /kg CD34+ dose (range 0.2–3.3 x 10 5 /kg). Engraftment Median interval to neutrophil engraftment was 19 days (range 14–45 days). Median time to platelet engraftment was 45 days (range 28–91 days). Neutrophil engraftment was defined as the first of three consecutive days with an absolute neutrophil count > 500. Platelet engraftment was defined as the first of three consecutive days of an absolute thrombocyte count of > 50. Chimerism analysis was done by variable number of tandem repeats (VNTR) by polymerase chain reaction (PCR) after engraftment, at day 60, and subsequently every year post HCT. Full donor chimerismwas defined as ≥ 95%donor derived hematopoietic stem cells, mixed chimerism if 10% to 94% donor derived hematopoietic cells were of donor origin, and autologous recovery if ≤ 10% of hematopoietic cells were donor derived. GvHD was scored according to standard criteria. 7 ASA activity was measured at