ORIGINAL ARTICLE Should the standard dimethyl sulfoxide concentration be reduced? Results of a European Group for Blood and Marrow Transplantation prospective noninterventional study on usage and side effects of dimethyl sulfoxide Curly Morris,1 Liesbeth de Wreede,2 Marijke Scholten,2 Ronald Brand,2 Anja van Biezen,2 Anna Sureda,3 Ebbe Dickmeiss,4 Marek Trneny,5 Jane Apperley,6 Patrizia Chiusolo,7 Gustaaf W. van Imhoff,8 Stig Lenhoff,9 Giovanni Martinelli,10 Marcus Hentrich,11 Thomas Pabst,12 Francesco Onida,13 Michael Quinn,14 Nicolaus Kroger,15 Theo de Witte,16 and Tapani Ruutu17 on behalf of the Chronic Malignancies and Lymphoma Working Parties of the EBMT
BACKGROUND: Dimethyl sulfoxide (DMSO) is essential for the preservation of liquid nitrogen–frozen stem cells, but is associated with toxicity in the transplant recipient. STUDY DESIGN AND METHODS: In this prospective noninterventional study, we describe the use of DMSO in 64 European Blood and Marrow Transplant Group centers undertaking autologous transplantation on patients with myeloma and lymphoma and analyze side effects after return of DMSO-preserved stem cells. RESULTS: While the majority of centers continue to use 10% DMSO, a significant proportion either use lower concentrations, mostly 5 or 7.5%, or wash cells before infusion (some for selected patients only). In contrast, the median dose of DMSO given (20 mL) was much less than the upper limit set by the same institutions (70 mL). In an accompanying statistical analysis of side effects noted after return of DMSO-preserved stem cells, we show that patients in the highest quartile receiving DMSO (mL and mL/kg body weight) had significantly more side effects attributed to DMSO, although this effect was not observed if DMSO was calculated as mL/min. Dividing the myeloma and lymphoma patients each into two equal groups by age we were able to confirm this result in all but young myeloma patients in whom an inversion of the odds ratio was seen, possibly related to the higher dose of melphalan received by young myeloma patients. CONCLUSION: We suggest better standardization of preservation method with reduced DMSO concentration and attention to the dose of DMSO received by patients could help reduce the toxicity and morbidity of the transplant procedure.
ABBREVIATIONS: BEAM = BCNU, etoposide, ARA-C, and melphalan; CLL = chronic lymphatic leukemia; EBMT = European Blood and Marrow Transplant Group; MM = multiple myeloma. From the 1Centre for Cancer Research and Cell Biology, Queen’s University of Belfast, Belfast, UK; the 2EBMT, Department of Medical Statistics and Bioinformatics, Leiden University Medical Center, Leiden, The Netherlands; the 3Department of Haematology, Addenbrooke’s Hospital, Cambridge University, Cambridge, UK; the 4Cell Therapy Section, Department of Clinical Immunology, Rigshospitalet, Copenhagen, Denmark; the 5Charles University Hospital, Prague, Czech Republic; the 6 Department of Haematology, Hammersmith Hospital, London, UK; the 7Istituto di Ematologia, Universita Cattolica S. Cuore, Rome, Italy; the 8Department of Hematology, University Medical Center Groningen, Groningen, The Netherlands; the 9 Department of Hematology, University Hospital, Lund, Sweden; the 10European Institute of Oncology, Milan, Italy; the 11 Klinikum Harlaching, Munich, Germany; the 12University Hospital Bern, Bern, Switzerland; the 13Department of Hematology and Oncology, University of Milan, Milan, Italy; the 14 Department of Haematology, Belfast City Hospital, Belfast, UK; the 15Department of Stem Cell Transplantation, University Hospital Hamburg-Eppendorf, Hamburg, Germany; the 16 Department of Hematology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands; and the 17 Department of Medicine, Helsinki University Central Hospital, Helsinki, Finland. Address reprint requests to: Curly Morris, Centre for Cancer Research and Cell Biology, Queens University of Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK; e-mail: [email protected]
Received for publication October 2, 2013; revision received February 18, 2014, and accepted February 20, 2014. doi: 10.1111/trf.12759 © 2014 AABB TRANSFUSION **;**:**-**. Volume **, ** **
MORRIS ET AL.
ore than 12,000 autologous transplants are carried out annually in Europe for patients with myeloma or lymphoma.1 With transplant-related mortality improving from 3% to 1% or less,2-4 the incidence of transplantrelated morbidity becomes of increasing importance. Early toxicity of the chemotherapy regimen is predictable but fortunately much of the nausea and vomiting is amenable to modern antiemetic techniques. As a result the toxicity of the aliquots of stored peripheral blood stem cells may contribute significantly to the morbidity related to their infusion. A number of factors may contribute to this toxicity including the total number of cryopreserved cells, the number of non– mononuclear cells (MNCs) and red blood cells (RBCs) cryopreserved. It has also been suggested the volume and duration of the stem cell infusion and even the age, sex, and diagnosis of the patient may be of significance.5-7 Dimethyl sulfoxide (DMSO), vital for cell viability in frozen aliquots, is known to be toxic and has numerous effects on cell differentiation and interactions with cytokines and has a number of well-identified side effects including nausea, vomiting, abdominal cramps, sedation, and headaches.8-10 Additionally DMSO is known to induce histamine release and may result in hypotension, bradycardia, hemolysis, rashes, renal failure, hypertension, heart block, pulmonary edema, cardiac arrest, bronchospasm, and neurologic damage.11,12 Reports of severe and even fatal side effects attributed to DMSO continue to be reported in transplant literature.13-20 Current apheresis techniques have reduced the level of RBC and granulocyte contamination of harvests but there has been little change in the procedure for freezing with respect to the amount of DMSO used. Recommendations for the concentration of MNCs may have increased the total volume (and thus the amount of DMSO in harvest)21 although these findings are subject to some dispute.22 In a previous report23 we have shown considerable variation in the concentration of DMSO that may be used for freezing stem cells successfully (from 2.2% to 20%). The vast majority of centers continue to use the standard of 10% DMSO despite a number of studies showing safe use of lower concentration.24-28 A number of centers remove DMSO before infusion by means of single or multiple washes.29-34 Other centers now limit the amount of DMSO that can be given in a specific period.35 Therefore, we developed a more detailed prospective noninterventional study to examine the strategies employed by the European Blood and Marrow Transplant Group (EBMT) centers to reduce the toxicity at transplantation and, in particular, strategies to reduce the amount of DMSO exposure and its impact on the patient experience. 2
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MATERIALS AND METHODS This noninterventional study was carried out at EBMT centers performing transplantations on patients with myeloma, lymphoma (Hodgkin’s lymphoma and nonHodgkin’s lymphoma), and chronic lymphatic leukemia (CLL; numbers and details in Table 1). In the initial part of the study, centers responded to questions about their use of DMSO including the concentration used in freezing cells and washing before returning to the patient and if there were any strategies utilized to reduce or limit the amount of DMSO given to patients in a specified time period. In the second part of the study the centers were asked to record the details of individual transplants, with particular emphasis on the amount of DMSO administered and the time period over which it was administered. As only 10 patients received DMSO on a third or subsequent day, doses of DMSO were calculated over up to 2 days only, in mL/min and in mL/kg body weight for each patient. At some stage between Day 7 and Day 14 posttransplant the units were asked to record side effects noted in the 24 hours after stem cell infusion with particular respect to nausea; vomiting; hypo- and hypertension (all grades); and other Grade 3, 4, or 5 side effects. For each side effect, it was asked whether it was (probably) attributable to DMSO or not, using the NCI Standard Criteria (Version 3.0). Returns were collated centrally by EBMT data managers.
Statistical analysis Statistical analysis of the clinical impact of the amount of DMSO administered to patients on side effects took place in three stages. In all models, the patient was the unit of analysis and the outcome measure was whether or not the patient experienced side effects (not differentiating between one or more side effects). As side effects from the same drugs may vary greatly between patients we also amalgamated all side effects to increase the power of the analysis. In the first analysis, the outcome was “any side effect assigned to DMSO.” In the current analyses we define the “effect” of DMSO as a comparison of the probability of such side effects occurring among the patients in the highest quartile of DMSO amount (as mL, mL/min, and mL/kg body weight) versus the patients in the lower three quartiles. In the analysis this quantity, the “relative risk,” is replaced by the odds ratio (OR), which compares the odds on side effects in the highest quartile against the odds in the other three quartiles, since the latter has better statistical properties and is the preferred way of quantifying relative risk in epidemiologic studies. Because of the heterogeneity among centers (center effect) with respect to the relationship between DMSO amount and side effects, we must estimate this OR for patients anyhow within each center and then “pool” those
DMSO SIDE EFFECTS IN AUTOLOGOUS TRANSPLANTATION
TABLE 1. Patient characteristics (n = 1651)* Variable All patients Sex (n = 1645) Male Female Age (years) at stem cell transplantation (n = 1628)