The influence of cell concentration at cryopreservation on neutrophil engraftment after autologous peripheral blood stem cell transplantation

ABSTRACT Background: Peripheral blood stem cell concentrations are traditionally adjusted to 20-40 × 106 leukocytes/mL prior to freezing. This low cell concentration at cryopreservation implies larger volumes with more dimethyl sulfoxide being used, and higher cost and toxicity at the time of transplant. Higher cell concentrations have been reported but this is not widely accepted. Moreover, the influence of cell concentration on engraftment has not been well documented. Therefore, this study retrospectively analyzed the influence of peripheral blood stem cell concentration at freezing on engraftment after autologous hematopoietic stem cell transplantation. Method: Leukapheresis products were plasma-depleted and cryopreserved with 5% dimethyl sulfoxide, 6% hydroxyethylamide solution and 4% albumin in a −80 °C freezer. Individual patient data from hospital records were reviewed. Results: Fifty consecutive patients with oncological diseases underwent 88 leukaphereses. Median age was six years (range: 1-32 years) and median weight was 19 kg (range: 8-94 kg). Median leukocyte concentration was 109 × 106/mL at collection and 359 × 106 (range: 58-676 × 106) at freezing with 78% viability (range: 53-95%); leukocyte recovery after thawing was 95% (range: 70-100%). In multivariate analysis, cell concentration (p-value = 0.001) had a negative impact on engraftment. Patients infused with bags frozen with <200 × 106 leukocytes/mL engrafted after a median of nine days (range: 8-12 days), 200-400 × 106 leukocytes/mL after 11 days (range: 9-20 days); 400-600 × 106 leukocytes/mL after 12 days (range: 8-19 days) and with cell concentrations >600 × 106 leukocytes/mL, engraftment was after 14 days (range: 13-22 days). Conclusion: In patients with adequate CD34 cell collections, total leukocyte concentrations of 282 × 106/mL, freezing with 5% dimethyl sulfoxide and 6% hydroxyethylamide solution without a controlled-rate freezer, and storing cells at −80 ºC yielded excellent engraftment. Further increases in cell concentration may delay engraftment, without affecting safety.

The influence of cell concentration at cryopreservation on neutrophil engraftment after autologous peripheral blood stem cell transplantation.

BACKGROUND: Peripheral blood stem cell concentrations are traditionally adjusted to 20-40 × 106 leukocytes/mL prior to freezing. This low cell concentration at cryopreservation implies larger volumes with more dimethyl sulfoxide being used, and higher cost and toxicity at the time of transplant. Higher cell concentrations have been reported but this is not widely accepted. Moreover, the influence of cell concentration on engraftment has not been well documented. Therefore, this study retrospectively analyzed the influence of peripheral blood stem cell concentration at freezing on engraftment after autologous hematopoietic stem cell transplantation. METHOD: Leukapheresis products were plasma-depleted and cryopreserved with 5% dimethyl sulfoxide, 6% hydroxyethylamide solution and 4% albumin in a -80 °C freezer. Individual patient data from hospital records were reviewed. RESULTS: Fifty consecutive patients with oncological diseases underwent 88 leukaphereses. Median age was six years (range: 1-32 years) and median weight was 19 kg (range: 8-94 kg). Median leukocyte concentration was 109 × 106/mL at collection and 359 × 106 (range: 58-676 × 106) at freezing with 78% viability (range: 53-95%); leukocyte recovery after thawing was 95% (range: 70-100%). In multivariate analysis, cell concentration (p-value = 0.001) had a negative impact on engraftment. Patients infused with bags frozen with <200 × 106 leukocytes/mL engrafted after a median of nine days (range: 8-12 days), 200-400 × 106 leukocytes/mL after 11 days (range: 9-20 days); 400-600 × 106 leukocytes/mL after 12 days (range: 8-19 days) and with cell concentrations >600 × 106 leukocytes/mL, engraftment was after 14 days (range: 13-22 days). CONCLUSION: In patients with adequate CD34 cell collections, total leukocyte concentrations of 282 × 106/mL, freezing with 5% dimethyl sulfoxide and 6% hydroxyethylamide solution without a controlled-rate freezer, and storing cells at -80 °C yielded excellent engraftment. Further increases in cell concentration may delay engraftment, without affecting safety.

Simultaneous Quantification of the 8 Human Herpesviruses in Allogeneic Hematopoietic Stem Cell Transplantation.

BACKGROUND: Human herpesviruses may cause severe complications after allogeneic hematopoietic stem cell transplantation (HSCT). However, the impact of some of these infections on transplant outcomes is still unclear. A prospective survey on the incidence and clinical features of herpesviruses infections after HSCT has not yet been conducted in Brazilian patients, and the impact of these infections on HSCT outcome remains unclear. METHODS: We prospectively analyzed the incidence of infection of the eight human herpesviruses simultaneously in 1 045 peripheral blood samples from 98 allogeneic HSCT recipients. Samples were collected weekly starting at the time of transplant until day +100. All herpesviruses were screened and quantified in plasma by quantitative real-time polymerase chain reaction. Median follow up time was 24 months. RESULTS: The incidences of infection for each herpesvirus were as follows: cytomegalovirus (CMV), 44%; human herpesvirus [HHV] 6, 18%; HHV8, 6%; Epstein-Barr virus, 3%; herpes simplex virus 1, 3%; varicella zoster virus, 3%; HHV7, 2%; and herpes simplex virus 2, 1%. The CMV infection was significantly more frequent among adults and was associated with a higher risk of developing acute graft-versus-host disease. The HHV6 infection was significantly more frequent after umbilical cord blood transplant and was associated with an increased risk of platelet engraftment failure. There was no significant impact of these infections on the other transplant outcomes. CONCLUSIONS: Herpesviruses infections were uncommon after HSCT, except for CMV and HHV6, which, although relatively frequent, had no clinically relevant impact on the outcomes.

Low Counts of Plasmacytoid Dendritic Cells after Engraftment Are Associated with High Early Mortality after Allogeneic Stem Cell Transplantation.

Dendritic cells (DCs) are antigen-presenting cells that drive immune responses and tolerance and are divided in different subsets: myeloid DCs (mDCs: lineage-; HLA-DR+, 11c+), plasmacytoid dendritic cells (pDCs: HLA-DR+, CD123+), and monocyte-derived DCs (moDC: lineage-, 11c+, 16+). After hematopoietic stem cell transplantation (HSCT), low DC counts in the recipients' peripheral blood (PB) have been associated with worse outcomes, but the relevance of DC graft content remains unclear, and there are few data in the setting of unrelated donor HSCT. We evaluated the DC graft content and monitored DC recovery in PB from 111 HSCT recipients (median age, 17 years; range 1 to 74), who received bone marrow (46%), umbilical cord blood (32%), or PB (22%) from unrelated (81%) or related donors (19%). In 86 patients with sustained allogeneic recovery, patients with higher counts of all DC subsets (pDC, mDC, and moDC) 3 weeks after engraftment had lower incidence of nonrelapse mortality (NMR) and acute graft-versus-host disease (aGVHD) and better survival. pDC counts were associated with more striking results: patients with higher pDC counts had much lower incidences of NRM (3% versus 47%, P < .0001), lower incidence of aGVHD (24% versus 67%, P < .0001), and better overall survival (92% versus 45%, P < .0001). In contrast, higher pDC counts in the graft was associated with an increased risk of aGVHD (55% versus 26%, P = .02). Our results indicate that DC counts are closely correlated with HSCT outcomes and warrant further prospective evaluation and possible early therapeutic interventions to ameliorate severe aGVHD and decrease mortality.

Changes in the use of the methylprednisolone protocol for traumatic spinal cord injury in Switzerland.

STUDY DESIGN: A retrospective cohort study. OBJECTIVE: To examine the differences in the use of the methylprednisolone protocol for traumatic spinal cord injury before and after the publication of new guidelines in Switzerland. SUMMARY OF BACKGROUND DATA: The use of the methylprednisolone protocol for traumatic spinal cord injury changed after the publication of new guidelines. The rate of physicians prescribing high-dose methylprednisolone for patients with acute spinal cord injury was studied. Two intervals, each comprising 24 months before and after the publication of the consensus article in Switzerland, were compared. As a secondary parameter, the neurological development during the rehabilitation period was compared. METHODS: The charts of all adult patients who were referred for treatment of a spine or spinal cord injury during the periods from April 2001 to March 2003 and from April 2008 to March 2010 were retrospectively reviewed for demographic and medical details, the application of methylprednisolone within the first 48 hours after the injury, the diagnoses at the time of their referral, and the diagnosis at the time of hospital discharge. Classification of traumatic spinal cord injury was made according to the guidelines of the American Spinal Injury Association. Neurological improvement concerning the level of injury was defined as a change of this segment to a more caudal one or a complete normalization of sensory and motor function. RESULTS: During the 2 study periods, 110 patients (2001-2003) and 116 patients (2008-2010) were included. Between 2001 and 2003, 96% of patients with a neurological deficit after spinal cord injury were treated with high-dose methylprednisolone, whereas this rate dropped to 23% during the second time interval. In both treatment periods, neurological improvement during the rehabilitation period (mean: 6 mo) did not differ significantly. Pooled data of all patients with a neurological deficit in both study periods (n = 159) showed improved neurological levels in 32% of patients treated with methylprednisolone and 28% of patients without this therapy, without a statistical difference between the groups. CONCLUSION: In Switzerland, the acceptance of the guidelines for treating traumatic spinal cord injury with high-dose methylprednisolone has been extremely high in the past. The use of high-dose methylprednisolone has decreased to a much lower level in Switzerland after the publication of new guidelines, which is comparable to various other countries. Despite these changes, no differences in the neurological outcome were detected between the observed patient populations.