Transfusion of platelet concentrates cryopreserved with ThromboSol plus low-dose dimethylsulphoxide in patients with severe thrombocytopenia: A pilot study

We have recently reported the possibility of supporting the phase of severe thrombocytopenia after high-dose chemotherapy (HDC) and stem cell transplantation using 5% dimethylsulphoxide (DMSO)-cryopreserved autologous platelet concentrates (PCs). The aim of the present study was to evaluate the therapeutic potential of ThromboSol (a recently developed platelet storage solution) plus PCs cryopreserved in 2% DMSO in patients undergoing myeloablative chemotherapy and autologous transplantation. PCs were collected from 14 women with breast cancer by a single plateletapheresis and cryopreserved in ThromboSol/2% DMSO by either direct insertion in a -80°C freezer or in liquid nitrogen after computer-controlled rate (CR) freezing. When required, PCs were thawed, centrifuged to remove the cryoprotectants and transfused. In vitro studies on thawed platelets showed loss of epitopes of surface glycoproteins and a marked reduction of functional activity compared with fresh platelets. Transfusion of CR-frozen PCs was associated with a mean 1 h corrected count increment (CCI) of 9.2 ± 5.4 x 10⁹/l and only one allogeneic PC was required in this group. In contrast, six out of seven patients required additional allogeneic transfusions in the -80°C group (CCI = 2.7 ± 1.4 x 10⁹/1). ThromboSol-treated PCs have the ability to overcome thrombocytopenia if processed by a CR freezing protocol, but appear ineffective when frozen by direct placing at -80°C.