Evaluation of a cryopreservation procedure to set up a new bone marrow transplant unit using lymphocyte proliferation test.

A bone marrow transplant (BMT) is one kind of standard treatment modality in advanced hemato-oncology. In order to set up a BMT unit, one of the important steps before starting a clinical program is to evaluate the cryopreservation procedure for stem cell storage. Twenty one bags of buffy coat were used to be the testing specimens. They were processed and frozen according to cryopreservation protocol and kept in liquid nitrogen for 2 weeks. The evaluation process was carried out with a lymphocyte proliferation test together with trypan blue staining. By measuring the optical density of each lymphocyte containing well after stimulation, the lymphocyte proliferation value (LPV) could be obtained. When comparing them before and after cryopreservation, the LPV was 2.064 ± 0.379 (mean ± SD) and 1.913 ± 0.546, (p = 0.314), respectively. At 2 weeks after cryopreservation, comparing between the frozen group and the unfrozen control, the LPV was 1.913 ± 0.546 and 0.486 ± 0.453, (p < 0.05), respectively. The LPV showed clear efficacy of the procedure, especially for preserving the cellular proliferation function. Our model of the cryopreservation procedure evaluation at pre-clinical phase by use of a buffy coat and lymphocyte proliferation test seems feasible for newly-established small BMT units. With these results, clinical transplantations can be performed with more confidence.