TY - JOUR AU - J Golay, AU - C Cortiana, AU - M Manganini, AU - G Cazzaniga, AU - A Salvi, AU - O Spinelli, AU - R Bassan, AU - T Barbui, AU - A Biondi, AU - A Rambaldi, AU - M Introna, PY - 2006/03/01 Y2 - 2024/03/28 TI - The sensitivity of acute lymphoblastic leukemia cells carrying the t(12;21) translocation to campath-1H-mediated cell lysis JF - Haematologica JA - haematol VL - 91 IS - 3 SE - Comparative Studies DO - 10.3324/%x UR - https://haematologica.org/article/view/3882 SP - 322-330 AB - BACKGROUND AND OBJECTIVES: Campath-1H is used in conditioning regimens and more recently as an anti-leukemic therapy in acute lymphoblastic leukemias (ALL). We therefore investigated CD52 expression and campath-1H-mediated lysis of ALL cells in vitro. DESIGN AND METHODS: Complement-mediated cytotoxicity assays were performed on freshly isolated neoplastic cells and cell lines using human serum. Antibody-dependent cellular cytotoxicity (ADCC) was performed by calcein-AM release assays. RESULTS: CD52 was expressed in four out of eight ALL cell lines studied. Among 61 freshly isolated ALL samples CD52 was expressed at varying levels in 87% of cases. Whereas ADCC was equivalent in different CD52+ lines, complement-dependent cytotoxicity (CDC) was variable. The REH cell line bearing the t(12;21) translocation showed 47-60% lysis when treated with 10 microg/mL campath-1H compared to 0-6% for the other cell lines expressing equivalent amounts of CD52. Furthermore all nine ALL samples with t(12;21) showed very high CDC (mean 97%) compared to the other 24 CD52+cases (mean 24%)(p