Transfusion of platelet concentrates cryopreserved with ThromboSol plus low-dose dimethylsulphoxide in patients with severe thrombocytopenia: a pilot study PAOLO P EDRAZZOLI , 1,2 PATRIZIA N ORIS , 3 C ESARE P EROTTI , 4 ROBERTA S CHIAVO, 2,5 L UISA P ONCHIO, 1 S IMONA B ELLETTI , 3 G IAN A NTONIO DA P RADA , 1 C ARLO L UIGI B ALDUINI , 3 L AURA S ALVANESCHI , 4 G IOACCHINO ROBUSTELLI DELLA C UNA 1 AND S ALVATORE S IENA 2,5 1 Divisione di Oncologia Medica, IRCCS Fondazione `S. Maugeri', Pavia, 2 Divisione di Oncologia Medica Falck, Ospedale Niguarda Ca' Granda, Milano, 3 Medicina Interna e Oncologia Medica, IRCCS Policlinico S. Matteo, Pavia, 4 Servizio di Immunoematologia e Trasfusione, IRCCS Policlinico S. Matteo, Pavia, and 5 Divisione di Oncologia Medica, Istituto Clinico Humanitas, Rozzano, Italy Received 28 July 1999; accepted for publication 13 October 1999 Summary. We have recently reported the possibility of supporting the phase of severe thrombocytopenia after high-dose chemotherapy (HDC) and stem cell transplanta- tion 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 transplanta- tion. PCs were collected from 14 women with breast cancer by a single plateletapheresis and cryopreserved in Thrombo- Sol/2% DMSO by either direct insertion in a 808C 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 glyco- proteins 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 6 5´4 ´ 10 9 /l and only one allogeneic PC was required in this group. In contrast, six out of seven patients required additional allogeneic transfusions in the 808C group (CCI  2´7 6 1´4 ´ 10 9 /l). 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 808C. Keywords: cryopreserved platelet concentrates, platelet transfusion, high-dose chemotherapy, ThromboSol, low- dose DMSO. High-dose chemotherapy (HDC) with stem cell support is effective in the treatment of a variety of poor-prognosis malignancies. Despite the remarkable amelioration of iatro- genic toxicity granted by circulating progenitor cell (CPC) transplantation and haematopoietic growth factors (Siena et al, 1994; Schmitz et al, 1997), severe thrombocytopenia requiring platelet transfusions remains a constant limitation in the management of myeloablated patients. Allogeneic transfusions carry the well-known risks of alloimmunization against HLA class I- and/or platelet-speci®c antigens, trans- mission of infections, graft vs. host disease and febrile non- haemolytic reactions (Dodd, 1994; Schreiber et al, 1996). Several strategies including leucodepletion or HLA-matched platelet transfusions and more ef®cacious viral screening have reduced, but not entirely abolished, the above-mentioned risks (Sniecinski et al, 1988; Goodnough et al, 1999; Roth et al, 1999). In addition, under current blood banking practices, platelets can be stored at 228C for only 5 d because of deterioration of function and because of the potential risk of bacterial contamination (Murphy, 1985; Yomtovian et al, 1993), often causing supply crises for blood banks. Ideally, the transfusion of cryopreserved autologous platelets is the best option, for at least three reasons: (a) avoiding alloimmunization; (b) preventing infections; and (c) amelioration of the logistical problems imposed by ¯uctua- tions in platelet supply and demand. Unfortunately, the currently approved methods for platelet cryopreservation are labour intensive and require high concentrations (5±6%) of British Journal of Haematology , 2000, 108, 653±659 653 q 2000 Blackwell Science Ltd Correspondence: Salvatore Siena, Director, Divisione di Oncologia Medica Falck, Ospedale Niguarda Ca' Granda, Piazza Ospedale Maggiore 3, 20162, Milano, Italy. E-mail: salvatore.siena@tin.it