Umbilical Cord Mesenchymal Stromal Cells for Steroid-Refractory Acute Graft-versus-Host Disease.

BACKGROUND: Steroid-refractory acute graft-vs.-host disease (SR-aGVHD) is a complication of allogeneic hematopoietic stem cell transplantation with a dismal prognosis and for which there is no consensus-based second-line therapy. Ruxolitinib is not easily accessible in many countries. A possible therapy is the administration of mesenchymal stromal cells (MSCs). METHODS: In this retrospective study, 52 patients with severe SR-aGVHD were treated with MSCs from umbilical cord (UC-MSCs) in nine institutions. RESULTS: The median (range) age was 12.5 (0.3-65) years and the mean ± SD dose (×106/kg) was 4.73 ± 1.3 per infusion (median of four infusions). Overall (OR) and complete response (CR) rates on day 28 were 63.5% and 36.6%, respectively. Children (n = 35) had better OR (71.5% vs. 47.1%, p = 0.12), CR (48.6% vs. 11.8%, p = 0.03), overall survival (p = 0.0006), and relapse-free survival (p = 0.0014) than adults (n = 17). Acute adverse events (all of them mild or moderate) were detected in 32.7% of patients, with no significant difference in children and adult groups (p = 1.0). CONCLUSIONS: UC-MSCs are a feasible alternative therapy for SR-aGVHD, especially in children. The safety profile is favorable.

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.

Large-volume leukapheresis for peripheral blood progenitor cell collection in low body weight pediatric patients: a single center experience.

Peripheral blood progenitor cells (PBPC) have became the preferred source of stem cells for autologous transplantation because of easier accessibility, rapid engraftment, and lower tumor cell contamination. In pediatric patients is very important to optimize peripheral blood stem cells (PBSC) harvesting to obtain a sufficient number of cells with a reduced number of leukapheresis. In this study we prospectively analyzed data on 43 large volume leukapheresis (LVL) from 20 consecutive low body weight pediatric patients with various malignancies. Patients' mean body weight was 16.6 kg (range, 8.9-32.0 kg), and the median age was 4 years (range, 1-10 y ears). Instead of saline, it was used irradiated and leukoreduced red blood cell (RBC) units to prime the machine in 15 patients weighting 25 kg or less. The median number of LVL was 2 (range, 1-4) and a mean of 5.2 patient's blood volume was processed per session lasting 165 min (range, 118-239). The mean number of CD34+ cells, one day before leukapheresis was 49 mm(-3) (range, 9-219). The PBPC collection yielded 24.7 x 10(8) total nucleated cells/kg (range, 6.2-74.0), 10.7 x 10(6) kg(-1) CD34+ cells (range, 3.6-53.7); 49.8 x 10(4) CFU-GM/kg (range, 6.4-198.1), and 65.6 x 10(4) BFU-E/kg (range, 7.6-198.1). The platelet count decreased significantly after each procedure 39.8 +/- 9.1 x 10(9) mm(-3) (range, 18.000-76.000) (p < 0.001). In conclusion, our data show that LVL for collection of PBPC in low weight pediatric patients is a safe and efficient procedure, but it may expose the patient to the risk of thrombocytopenia.

Use of amifostine in the therapy of osteosarcoma in children and adolescents.

Amifostine protects normal tissue from the cytotoxic damage induced by radiation and chemotherapy. In this study, 39 consecutive newly diagnosed children with osteosarcoma were assessed; 20 received amifostine and 19 did not. The chemotherapy regimen included an induction phase of three cycles of cisplatin (100 mg/m2), carboplatin (500 mg/m2), and doxorubicin (60 mg/m2), followed by surgery. Alternating cycles of cisplatin/ifosfamide (9 mg/m2), ifosfamide/doxorubicin, carboplatin/doxorubicin, and ifosfamide/carboplatin were administered every 3 weeks to complete 26 weeks of treatment. Amifostine was administered 15 minutes before the infusions of cisplatin and carboplatin in a total of 193 infusions. Side effects during infusions and renal, hearing, and bone marrow toxicities were evaluated and compared between the two groups. Hypotension was observed in 28 (14.5%) infusions. No patient required discontinuation of therapy. Fewer than two episodes of vomiting occurred in 130 (71%) infusions and two to five episodes occurred in 51 (28%) infusions, and no patient had grade 4 toxicity. There was no difference between the two groups regarding renal toxicity (creatinine clearance). Neutropenia and leukopenia were significantly less frequent in the amifostine group. No difference was observed in platelet and hearing toxicities. Amifostine was well tolerated in doses of 740 mg/m2 in children and adolescents, and myelotoxicity was less severe in the amifostine group. This was a pilot study for further evaluation in a larger randomized trial.