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 1x10 (6)/mL with 50-500 microg/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.