Comparison of the Cytotoxicity of 4 Preparations of Anti-T-cell Globulins in Various Hematological Malignancies

Objective: The cytotoxic effects of 4 ATG preparations (Thymoglobulin®, ATG-Fresenius®, Lymphoglobulin® and ATGAM®) in hematological malignancies were compared. Materials and Methods: Myeloma, myeloid leukaemia and lymphoma cell lines as well as primary CLL and T-cell samples were used. Cells were incubated at 1×10 6 /mL with 50-500 μg/mL of various ATG preparations with or without complement. Cell viability was analyzed by flow cytometry. Results: All ATG preparations had potent and similar cytotoxic activity against T-cells, primary CLL cells, NHL cell lines and myeloma cell lines. Resistance of U266 myeloma cells to ATG-induced apoptosis is shared by all 4 ATGs and can be overcome by addition of complement. Conclusion: All 4 ATGs have similar cytotoxic activity against hematological malignancies in vitro. If ATGs are used to target hematological malignancies, the choice of which ATG to use would depend on whether the required ATG concentration can be achieved in vivo.