Transfusion dependency at diagnosis and transfusion intensity during initial chemotherapy are associated with poorer outcomes in adult acute myeloid leukemia.

Blood transfusions can modify host immunity and clinical outcomes in hematological malignancies. One thousand sixty-seven patients with acute myeloid leukemia (AML) were studied for their transfusion dependency at initial presentation and transfusion frequency during induction chemotherapy. Three hundred five patients (29 %) showed initial dependence to red blood cell (RBC) transfusion and 109 (10 %) to platelet transfusion. Transfusion dependency at presentation was associated with a poorer prognosis. Both initial RBC and platelet transfusion needs were associated with lower response rates (P = 0.04 and P = 0.03). Median overall survival (OS) was 10.8 months for patients with RBC need vs 18.8 months for the other patients (P = 0.02) and 6.8 months for patients with platelet transfusion need vs 13.6 months for the others (P = 0.01). Similarly, transfusion intensity during induction therapy influenced negatively treatment outcome. Median transfusion burden per week was 2.5 (range 0-25.7) RBC units and 1.6 (range 0-15.7) platelet concentrates (PCs). Both high RBC and PC transfusion intensities were associated with lower response rates (P = 0.003 and P < 0.0001). Median OS was 9.08 months for patients with RBC transfusions >3/week vs 18.29 months for those with RBC transfusions ≤3/week (P = 0.0003) and 10.75 months for patients with PC transfusions >2/week vs 19.96 months for those with PC ≤2/week (P = 0.0003). RBC and platelet transfusion intensities during induction therapy remained of prognostic value in multivariate analysis. Transfusion need at presentation and the frequency of transfusions during induction chemotherapy appear as strong prognostic factors.

Polymer brush covalently attached to OH-functionalized mica surface via surface-initiated ATRP: control of grafting density and polymer chain length.

The controlled grafting density of poly(tert-butyl acrylate) was studied on OH-activated mica substrates via surface-initiated atom-transfer radical polymerization (ATRP). By properly adjusting parameters such as the immobilization reaction time and the concentration of an ATRP initiator, a wide range of initiator surface coverages and hence polymer densities on mica were possible. The covalently immobilized initiator successfully promoted the polymerization of tert-butyl acrylate on mica surfaces. The resulting polymer layer thickness was measured by AFM using a step-height method. Linear relationships of the polymer thickness with respect to the molecular weight of the free polymer and with respect to the monomer conversion were observed, suggesting that ATRP is well controlled and relatively densely end-grafted layers were obtained. The polymer grafting density controlled by adjusting the initiator surface coverage was confirmed by the polymer layer swelling capacity and film thickness measurements.