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Liquid storage of stem cell harvest at 4 degree C upto 8 days results in timely engraftment
- Pankaj Malhotra, Neelam Varma, Subhash Varma (17 July 2007)
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Pankaj Malhotra, Assistant Professor PGIMER, Chandigarh, India 160012, Neelam Varma, Subhash Varma
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Wannesson L et al. [1] in their systemic review on feasibility and safety of autotransplants with noncryopreserved marrow or peripheral blood stem cells mentioned “the sooner the better approach” and reinfusion of stem cells within 3-5 days of harvest. We have been carrying out stem cell transplant at our centre using liquid storage of stem cells at 40C in multiple myeloma since 2003. Our experience of extended storage of liquid preserved stem cells for multiple myeloma had already been published [2]. Studies done at our centre shows that viability of liquid preserved stem cells remain more than 90% for almost 10 days from the day of harvest. Consequently we carried out our first autologous peripheral blood stem cell transplant for refractory Hodgkin lymphoma in a 28-year old man using LACE-conditioned protocol [3]. The LACE chemotherapy regimen consisted of oral lomustine (CCNU) 200 mg/m2 on day-7, intravenous etoposide 1000 mg/m2 infused over 10 h on day -7, intravenous cytarabine (Ara-C) 2000 mg/m2 infused over 12 h on days -6 and -5 and intravenous cyclophosphamide 1800 mg/m2 infused over 1 h on days -4, -3 and -2. Patients also received intravenous MESNA 1800 mg/m2 twice daily over 12 h on days -4,-3 and -2. Two peripheral blood stem cell collections were done on day -8 and -7 after mobilization with granulocyte colony stimulating factor (G-CSF) and CD34+ count of 1.05x106/kg and 3.03x106/kg were obtained respectively. Both harvests were stored at 40C. High dose chemotherapy was then initiated on the day of second harvest (day -7). Both autologous stem cells were infused on day 0, 48 h after the end of the last cyclophosphamide infusion. The viability of stem cells of both harvests on the day of reinfusion was more than 90%. Neutrophil engraftment (absolute neutrophil count >500/µl) took place on day+12 and platelet engraftment (unsupported platelet count of >20,000/µl) took place on day+20 which is comparable with large published series on this protocol [3]. We use G- CSF from day+5 onwards. We have been carrying out stem cell transplants at our centre using liquid storage of stem cells at 40C for last 4 years and stem cell engraftment had taken place in all patients with no case of graft failure. We could not agree more than with the authors who must be complimented for doing a systemic review of all studies where noncryopreserved stem cells had been used with high dose chemotherapy followed by autologous transplants. However, we disagree with the authors that stem cell transplants using noncryopreserved stem cells have limitation in the setting of applying high dose chemotherapy schedule and successful autologous transplant in Hodgkin’s lymphoma with LACE conditioned protocol illustrated above is an example of that. We have been conducting viability studies with trypan blue dye exclusion on autologous stem cell collections from the day of harvest till 10 days and our results on last 8 collections show that viability of stem cells more than 90% upto 10 days of harvest in 5 collections. In three harvests, stem cell viability by trypan blue dye exclusion fell down to 80% by 10th day. Hence we feel that high dose chemotherapy and rescue with noncryopreserved stem cells may not be a limitation as stem cell harvests can be safely stored in liquid medium at 40C for a minimum of 8 days and possibly upto 10 days. The liquid preservation would also decrease the cost associated with cryopreservation of stem cells. The only disadvantage may be difficulty in carrying out elective transplants at a later date or when more than one transplant is planned. References 1. Wannesson L, Panzarella T, Mikhael J, Keating A. Feasibility and safety of autotransplants with noncryopreserved marrow or peripheral blood stem cells: a systemic review. Ann Oncol 2007; 18:623-32. 2. Thakral B, Saluja K, Sharma RR et al. Extended storage of liquid- preserved stem cells at 40C results in good engraftment in patients of multiple myeloma undergoing autologous stem cell transplantation. Lab Med 2005; 36: 650-51. 3. Perz JB, Giles C, Szydlo R et al. LACE-conditioned autologous stem cell transplantation for relapsed or refractory Hodgkin’s lymphoma: treatment outcome and risk factor analysis in 67 patients from a single centre. Bone marrow transplant 2007;39: 41-47 *Pankaj Malhotra, Neelam Varma, Subhash Varma Department of Internal Medicine and Haematology Post Graduate Institute of Medical Education and Research Chandigarh 160012 India *Corresponding author Email: malhotrapankaj@yahoo.com Fax: +91-172-2747124 Conflict of Interest:None declared |
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