Allogeneic Peripheral Blood Progenitor Cell Research Articles

Effectiveness of single-dose 6 mg pegfilgrastim in mobilizing peripheral blood stem cells in allogeneic hematopoietic cell transplantation donors.

A single injection of 12 mg pegfilgrastim was used to mobilize peripheral blood progenitor cells (PBPCs) from healthy donors in some studies. The purpose of this study was to determine if 6 mg of pegfilgrastim was effective and safe for mobilizing CD34+ cells in donors for allogeneic hematopoietic stem cell transplantation. We conducted a retrospective case-matched design. A single dosage of 6 mg pegfilgrastim was used to mobilize PBPCs from 60 healthy donors. Granulocyte colony-stimulating factor (G-CSF, 10 μg/kg) was administered daily to the matched donors. Leukapheresis was scheduled to commence on day 4 of the mobilization regimen. The median yielded CD34+ cell in the pegfilgrastim group was higher than those in the G-CSF group, at 5.06 × 106/kg recipient weight. The 73.3% of donors mobilized with pegfilgrastim yielded >4 × 106 cells/kg CD34+ cells in a single apheresis procedure when compared to the 33.3% of donors mobilized with G-CSF (P < 0.001). The myeloid-derived suppressor cells (MDSC) proportion in the pegfilgrastim group was significantly higher than that in the G-CSF group (P < 0.001). The cumulative incidence of grade II-IV acute graft-versus-host disease (aGVHD) was higher in the G-CSF group than that in the pegfilgrastim group (26.7% vs. 11.7%), without statistical difference. In comparison to the G-CSF group, the pegfilgrastim group had a reduced median pain intensity numerical rating scale score (1 vs. 2). A single 6 mg dosage of pegfilgrastim is effective and safe for allogeneic PBPCs collection from healthy donors. Pegfilgrastim may decrease the incidence of aGVHD by boosting MDSCs, which need further investigation.

233 - Impact of the COVID-19 Pandemic on Unrelated Allogeneic Hematopoietic Peripheral Blood Progenitor Cell Collections in Canada

233 - Impact of the COVID-19 Pandemic on Unrelated Allogeneic Hematopoietic Peripheral Blood Progenitor Cell Collections in Canada

Feasibility and cost analysis of day 4 granulocyte colony-stimulating factor mobilized peripheral blood progenitor cell collection from HLA-matched sibling donors

BackgroundGuidelines recommend treatment with 4–5 days of granulocyte colony-stimulating factor (G-CSF) for optimal donor peripheral blood progenitor cell (PBPC) mobilization followed by day 5 collection. Given that some autologous transplant recipients achieve adequate collection by day 4 and the possibility that some allogeneic donors may maximally mobilize PBPC before day 5, a feasibility study was performed evaluating day 4 allogeneic PBPC collection. MethodsHLA-matched sibling donors underwent collection on day 4 of G-CSF for peripheral blood (PB) CD34+ counts ≥0.04 × 106/mL, otherwise they underwent collection on day 5. Those with inadequate collected CD34+ cells/kg recipient weight underwent repeat collection over 2 days. Transplant and PBPC characteristics and cost analysis were compared with a historical cohort collected on day 5 per our prior institutional algorithm. ResultsOf the 101 patient/donor pairs, 50 (49.5%) had adequate PBPC collection on day 4, with a median PB CD34+ cell count of 0.06 × 106/mL. Day 4 donors were more likely to develop bone pain and require analgesics. Median collected CD34+ count was significantly greater, whereas total nucleated, mononuclear and CD3+ cell counts were significantly lower, at time of transplant infusion for day 4 versus other collection cohorts. There were no significant differences in engraftment or graft-versus-host disease. Cost analysis revealed 6.7% direct cost savings for day 4 versus historical day 5 collection. DiscussionDay 4 PB CD34+ threshold of ≥0.04 × 106/mL identified donors with high likelihood of adequate PBPC collection. Day 4 may be the optimal day of collection for healthy donors, without adverse effect on recipient transplant outcomes and with expected cost savings.

Feasibility and Cost Analysis of Day 4 Granulocyte Colony-Stimulating Factor Mobilized Peripheral Blood Progenitor Cell Collection from HLA-Matched Sibling Donors

Feasibility and Cost Analysis of Day 4 Granulocyte Colony-Stimulating Factor Mobilized Peripheral Blood Progenitor Cell Collection from HLA-Matched Sibling Donors

Feasibility and Cost Analysis of Day 4 Granulocyte Colony-Stimulating Factor Mobilized Peripheral Blood Progenitor Cell Collection from HLA-Matched Sibling Donors

Introduction: Published guidelines recommend mobilization of allogeneic peripheral blood progenitor cells (PBPC) with 4-5 days of granulocyte colony-stimulating factor (G-CSF) followed by PBPC collection on day 5. Given that some autologous transplant patients are adequately mobilized by day 4, and concern that a subset of allogeneic donors may be maximally mobilized before day 5 of G-CSF administration, we performed a feasibility study evaluating day 4 allogeneic PBPC collection.Methods: This single-center prospective study included adult patients with malignant diseases who received a first allogeneic hematopoietic stem cell transplant (HCT) at our center between 7/1/2013 - 6/30/2017. HLA-matched sibling donors received 10 μg/kg of G-CSF subcutaneously prior to PBPC collection. Donors were collected on day 4 of G-CSF if peripheral blood (PB) CD34+ counts were ≥0.04x106/ml. Donors with day 4 PB CD34+ counts <0.04x106/ml were collected on day 5, and those with inadequate collected CD34+ cells/kg recipient weight underwent repeat collection over two days. Patient and donor characteristics, PBPC product composition, transplant outcomes, and cost analysis of the PBPC collection procedure were compared to a historical cohort of donors collected on day 5 according to our prior algorithm.Results: One hundred and one patients/donors were eligible for inclusion on study, and 75 were included in the historical cohort. Of the 101 donors on study, 50 (49.5%) had adequate PBPC collection on day 4 of G-CSF, 26 (25.7%) were collected on day 5, and 25 (24.8%) required two-day collections on days 4 and 5. The median day 4 donor PB CD34+ cell count was 0.06 (range 0.03-0.13) x 106/ml among donors collecting on day 4, 0.03 (range 0.007-0.09) x 106/ml for donors collecting on day 5, and 0.019 (range 0.004-0.04) x 106/ml for donors collecting over two-days (p<0.001).The most common reported donor symptoms were bone pain, myalgia/malaise, headache, and circumoral tingling/electrolyte abnormalities. Compared to the historical cohort, donors with PBPC collection on day 4 were significantly more likely to develop bone pain, require narcotics, and take over-the-counter (OTC) medications, day 5 donors were significantly more likely to develop bone pain and take OTC medications, and two-day donors were significantly more likely to develop bone pain and circumoral tingling/electrolyte abnormalities.The median collected PBPC CD34+ cell count (7.25 x 106/kg recipient weight) and infused PBPC product CD34+ cell count (5.67 x 106/kg recipient weight) were significantly greater in products collected on day 4, compared to products collected on other days. In comparison, the infused PBPC product total nucleated cell (TNC) count (7.13 x 108/kg recipient weight), mononuclear cell (MNC) count (5.84 x 108/kg recipient weight), and CD3+ cell count (2.14 x 108/kg recipient weight) were significantly lower in products collected on day 4 compared to other collection cohorts (p<0.001, p<0.001, and p=0.002, respectively for day 5, two-day, and historical cohort).There were no significant differences in time to neutrophil or platelet engraftment, or in the incidence of acute or chronic graft-versus-host-disease, based on day of collection. There was a non-significant trend towards improved 1-year survival among patients transplanted with PBPC collected on day 4 (p=0.077). Cost analysis revealed a 6.7% savings in direct costs per collection procedure for the day 4 collection method versus historical cohort.Conclusions: Using a day 4 PB CD34+ threshold of ≥0.04x106/ml identifies donors with a high likelihood of adequate PBPC collection. While differences in PBPC product composition and donor symptoms were seen based on day of collection, we found no evidence of adverse post-HCT outcomes associated with day 4 PBPC collection. Day 4 may be the optimal day of stem cell collection for a population of healthy donors without adverse effect on transplant outcomes, and with an anticipated cost savings. Ongoing analyses include resource utilization review, matched cohort analysis of day 4 versus 5 collection and correlation with transplant outcomes, more detailed PBPC production composition analysis among the collection cohorts, and longer post-HCT follow-up and association with outcomes based on day of PBPC collection. These findings merit further analysis in larger HCT cohorts. [Display omitted] DisclosuresCook:Syros Pharmaceuticals: Consultancy. Maziarz:Incyte: Consultancy, Honoraria; Kite Therapeutics: Honoraria; Novartis Pharmaceuticals Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Athersys, Inc.: Patents & Royalties; Juno Therapeutics: Consultancy, Honoraria.

Plerixafor As a Salvage Regimen to Mobilize Allogeneic Stem Cells in Healthy Volunteers (NCT01954914)

Introduction: Insufficient yield of Peripheral Blood Progenitor Cells (PBPC) from healthy donors can result in higher mortality after allogeneic transplantation. Plerixafor (Mozobil®) is approved for the mobilization of PBPC in combination with G-CSF for collection and subsequent autologous transplantation in patients with non-Hodgkin lymphoma and multiple myeloma. Clinical data on G-CSF and Plerixafor in healthy donors are still limited. In a prospective single arm phase 2 trial we investigated the safety and efficacy of a single dose of Plerixafor as a salvage regimen in poor mobilizing allogeneic PBPC donors (NCT01954914).Methods: We enrolled healthy unrelated PBPC donors who had received G-CSF (Lenograstim) at a targed dose of 10 µg/kg bodyweight (bw) for five days but donated less than 2x 106 CD34+ cells/kg recipient bw during the 1st apheresis on day 5 of the mobilization regimen. Plerixafor was injected subcutaneously at a dose of 240µg/kg once on day 5 in the evening before the second leukapheresis. The target for the processed blood volume during each apheresis procedure was 3x donor blood volume +/- 25%. Mobilization success was defined by a donation of more than 4.5x 106CD34+ cells/kg recipient bw. Primary endpoint was the number of mobilization successes. The null hypothesis (success rate of less than 50%) was tested with an exact single sample binomial test at a one-sided significance level of 5%.Results: Between 1/2014 and 12/2015 37 allogeneic unrelated PBPC donors (54% women, 46% men, median age 34 years) were enrolled into the study. The median donor bw was 69 kg (IQR, 61 kg to 76 kg) and the median recipient bw was 85 kg (IQR, 74 kg to 102 kg). Application of Plerixafor was well tolerated in most donors with only moderate side effects such as nausea, diarrhea and occasional vomiting. The median CD34+ count in peripheral blood was 15.4/µl (IQR, 12.0-18.3) on day 5 after G-CSF alone and 44.0/µl (IQR, 38.0-60.5) on day 6 after G-CSF plus Plerixafor. The collected total nucleated cell count was 187 x 106 (IQR, 159.9-223.4) cells per ml volume of the apheresis product on day 5 and 289 x 106 (IQR, 248.0-348.0) cells per ml volume of the apheresis product on day 6. The yield of CD34+ cells in the apheresis products was 1.05 x 108 (range, 0.21-1.80) on day 5 and 2.8 x108(range, 0.93-5.26) on day 6. The percentage of CD3+ cells per TNC was 31% (IQR 27%-40%) and 31% (IQR, 23% - 35%) on days 5 and 6, respectively.In total, a median number of 5.16 x 106 CD34+ cells (IQR 3.06-6.10) per kg recipient weight were collected during both aphereses. Twenty-one out of 37 donors reached the target cell count (56.8%, 95% confidence interval (CI) 39.5% - 72.9%) by donating a CD34+ cell dose of >4.5x 106 CD34+ cells per kg recipient bw. Nine donors had donated ≤0.8 106 CD34+ cells per kg recipient bw during their first leukaphersis after stimulation with G-CSF alone. Notably, only one out of these nine very poor mobilizing donors failed to donate at least 2.0 x 106CD 34+ cells per kg recipient bw after salvage mobilization with Plerixafor. Nevertheless, the null hypothesis (H0: rate of mobilization success <50%) could not be rejected at the 5% level (p= 0.2557).Conclusions: In this trial in poor mobilizing healthy unrelated donors the rate of mobilization success (donation of >4.5x 106 CD34+ cells per kg recipient bw) was 56.8% (95%-CI 39.5% - 72.9%) after a single dose of Plerixafor on day 5 of G-CSF administration. After injection of Plerixafor the CD34+count in the peripheral blood and the yield of CD34+ cells in the leukapheresis product increased by more than factor 2. The application of G-CSF and Plerixafor was well tolerated by most of the donors. Like for autologous donors, the administration of Plerixafor appears promising to optimize PBPC mobilization in allogeneic poor mobilizing donors. DisclosuresHoelig:Janssen Cilag GmbH: Honoraria; Therakos: Honoraria, Research Funding; Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Schetelig:Sanofi: Honoraria.

Immune Reconstitution after Umbilical Cord Blood Versus Peripheral Blood Progenitor Cell Transplantation in Adults Following Myeloablative Conditioning

Immune Reconstitution After Umbilical Cord Blood Versus Peripheral Blood Progenitor Cell Transplantation In Adults Following Myeloablative ConditioningIntroduction: We report on the tempo of immune reconstitution after myeloablative umbilical cord blood transplantation (UCBT, n=61) compared with allogeneic peripheral blood progenitor cells transplantation (PBPCT, n=59).Methods: All patients 18 years or older who underwent first allogeneic transplantation after myeloablative conditioning for hematological malignancies between Jan, 2004 and Dec, 2013 and were alive at 1-year post transplant were included. Patients who received T-cell depletion or antithymocyte globulin were excluded.Results: Overall, the most common diagnosis was acute (83.6% vs 61%) or chronic (3.3% vs. 10.2%) leukemia in UCBT and PBPCT groups, respectively, p=0.07. Median age of UCBT group was 37.2 years vs. 45 years in PBPCT group, p<0.01. The majority of UCBT group (92%) received two units. Almost all patients in PBPCT group (97%) had 6/6- or 8/8-HLA matched sibling donor. More than half of recipients of either UCBT (54%) or PBPCT (51%) were cytomegalovirus (CMV) seropositive. About 97% in both groups received total body irradiation (TBI) for conditioning. Graft-versus-host disease (GVHD) prophylaxis was provided with cyclosporine plus either mycophenolate (UCBT) or methotrexate (PBPCT).The median time to neutrophil engraftment was notably faster in the PBPCT group (15 days, range 10-31) compared with the UCBT group (24 days, range 6-39), p<0.001. All subsets of cells analyzed were significantly lower in the UCBT group for at least first month post-transplant compared with PBPCT group [Figures 1-3]. Natural killer (NK) cells were the first cells to reconstitute in the UCBT group, especially the CD56bright subset, the absolute numbers of which were significantly higher in UCBT than in the PBPCT group from 2 months until at least one year. Similarly, although CD19+ B cells were lower in UCBT group for first month post- transplant, they reached comparable levels to that of PBPCT group at 2-3 months post-HCT and then surpassed the PBPCT group with UCB having significantly higher numbers at 6 and 12-months post-HCT (p<0.05). The absolute numbers of total T cells (CD3+CD56-), CD4+ and CD8+ T cells remain significantly lower in the UCBT group until 3 months, but were then comparable to that of PBPCT group at 6 and 12 months. "NKT" cells (CD3+CD56+) and the naïve T cells (CD4+CD45RO-CD27+) remain significantly lower in UCBT group at all time points tested. The numbers of effector memory (CD4+CD45RO+CD27-) and central memory T cells (CD4+CD45RO+CD27+) were lower for the first three months after transplant, but were then comparable to the PBPCT group thereafter. Regulatory T cells (Tregs; CD4+CD25brightCD127-) were lower in UCBT group for the first 6 months and then comparable to PBPCT group at 12 months.Clinical correlates: Infection density at 1 year (number of infection events/1000 patient days at risk) of bacterial (6.3 vs. 3.7, p<0.01) and viral (5.4 vs 2.2, p<0.01), but not fungal infections (0.27 vs. 0.34, p=0.69) was significantly higher in the UCBT group than in the PBPCT group, respectively. UCBT group had a significantly higher incidence of acute grade II-IV GVHD (75%, 95% confidence interval (CI) 61- 90%, versus 51%, 95% CI 37-65%, p<0.01) and grade III-IV GVHD (33%, 95% CI 21-45%, versus 17%, 95% 7-26%, p=0.03) than PBPCT group respectively. Incidence of chronic GVHD at 2 years was similar in two groups. In univariate analysis, risk of relapse at 3-years was significantly lower in UCBT (19%, 95% CI 9-28%) than PBPCT group (35%, 95% CI 22-48%), p=0.05. There was no difference in overall survival at 3 years (72% vs 66%, respectively, p=0.34).Conclusion: After myeloablative conditioning, UCBT group has significantly delayed neutrophil engraftment and reconstitution of all T cell subsets and NKT cells, compared to that of PBPCT group, which along with a higher incidence of acute GVHD explains higher infection density in the UCBT group. Conversely, rapid recovery of NK and B cells may partly explain lower risk of relapse in the UCBT group. Despite significantly lower numbers of Tregs in UCBT group, risk of chronic GVHD was similar to that of PBPCT group. Ongoing multivariate analysis of the impact of CMV serostatus and other cell subsets on clinical outcomes will provide further answers. [Display omitted] [Display omitted] [Display omitted] DisclosuresMiller:Oxis Biotech Scientific Advisory Board: Membership on an entity's Board of Directors or advisory committees.

Immunotherapy following relapse of acute leukaemia after T‐cell‐replete allogeneic peripheral blood progenitor cell transplantation: importance of new onset chronic graft‐versus‐host disease

To further define the relative impact of immunotherapy and subsequent development of graft-versus-host disease (GVHD) on survival in patients with relapsed acute leukaemia postallogeneic hematopoietic stem cell transplant (SCT), we performed a single-centre retrospective analysis of 32 actively treated patients between 2003 and 2011. A total of 13 patients were identified who were treated actively with cessation of immunosuppression ± Fludarabine, Cytarabine, G-CSF (FLAG) induction, but no donor leucocyte infusion (DLI) (non-DLI group) and 19 patients received the same step-wise therapy plus G-CSF mobilized DLI (G-DLI group). Groups were not statistically different with regards to baseline characteristics; however, the G-DLI group contained more sibling donors as opposed to unrelated donors than the non-DLI group. With a median follow-up of 47months, the median overall survival (OS) of the non-DLI and G-DLI groups was not statistically different (8months vs. 9months, respectively, P=0.5). Survival at 3years was <10% in both groups. Univariate analysis identified response to FLAG, and new onset chronic GVHD as the only factors associated with improved OS. Second donor stem cell infusions are unwarranted in the treatment of relapse after allogeneic SCT and therapeutic strategies should focus on cytoreduction followed by immune modulation with the aim of invoking chronic GVHD.

Rapid donor T‐cell engraftment increases the risk of chronic graft‐versus‐host disease following salvage allogeneic peripheral blood hematopoietic cell transplantation for bone marrow failure syndromes

The risk of graft-rejection after allogeneic hematopoietic cell transplantation using conventional cyclophosphamide-based conditioning is increased in patients with bone marrow failure syndromes (BMFS) who are heavily transfused and often HLA-alloimmunized. Fifty-six patients with BMFS underwent fludarabine-based reduced-intensity conditioning and allogeneic peripheral blood progenitor cell (PBPC) transplantation at a single institution. The conditioning regimen consisted of intravenous cyclophosphamide, fludarabine, and equine antithymocyte globulin. Graft-versus-host disease (GVHD) prophylaxis included cyclosporine A alone or in combination with either mycophenolate mofetil or methotrexate. To reduce the risk of graft-rejection/failure, unmanipulated G-CSF mobilized PBPCs obtained from an HLA-identical or single HLA-antigen mismatched relative were transplanted rather than donor bone marrow. Despite a high prevalence of pretransplant HLA-alloimmunization (41%) and a heavy prior transfusion burden, graft-failure did not occur with all patients having sustained donor lympho-hematopoietic engraftment. The cumulative incidence of grade II-IV acute-GVHD and chronic-GVHD was 51.8% and 72%, respectively; with 87.1% surviving at a median follow-up of 4.5 years. A multivariate analysis showed pretransplant alloimmunization and rapid donor T-cell engraftment (≥95% donor by day 30) were both significantly (P < 0.05) associated with the development of chronic-GVHD (adjusted HR 2.13 and 2.99, respectively). These data show fludarabine-based PBPC transplantation overcomes the risk of graft-failure in patients with BMFS, although rapid donor T-cell engraftment associated with this approach appears to increase the risk of chronic-GVHD. (Clinicaltrials.gov identifier: NCT00003838).

Higher Doses of CD34+ PBPC are Associated With a Rapid Acquisition of Full Donor Chimerism and Lower Risk of Relapse After Allogeneic Transplantation in Pediatric Patients With Hematological Malignancies

We conducted a retrospective study assessing the predictive value of early full donor chimerism status for relapse after allogeneic peripheral blood progenitor cell transplantation in 40 children aged between 1 and 16 years (median 8) with leukemia. The only variable that had a significant influence on chimerism status in either univariate or multivariate analysis was the number of CD34 cells infused. We found that the patients who were in complete donor chimerism by day +30 had a lower probability of relapse than those who were not (14% ± 6% versus 54% ± 15%; HR, 5.24; 95% confidence interval, 2.10-43.63; P = 0.003). Mixed chimerism by day +30, absence of chronic GvHD, and advanced disease at transplantation were significant risk factors for relapse in our patients. Children who presented early complete chimerism had a probability of developing chronic graft versus host disease significantly higher than patients with mixed chimerism (P = 0.04). Therefore, the analysis of chimerism kinetic in children undergoing peripheral blood progenitor cell transplantation would permit an early identification of patients at risk of relapse and patients with high risk of developing chronic graft versus host disease.

Stem cell harvesting and transplantation

Allogeneic haematopoietic stem cell transplantation is an accepted treatment for a variety of malignant and non‐malignant diseases. Today, peripheral blood progenitor cells (PBPC) are increasingly used instead of bone marrow (BM) as stem cell source. Additionally, umbilical cord blood (UCB) has been established as an alternative source of donor cells. Many differences between the distinct stem cell sources do exist. PBPC contain a higher amount of CD34 + cells compared with BM and UCB, leading to more rapid engraftment with the disadvantage of a higher incidence of chronic graft‐versus‐host disease. In contrast to adults, children seem to have a better outcome after BM than PBPC transplantation. Therefore, especially patients with non‐malignant diseases and children should be transplated with BM. The disadvantage of the significantly lower CD34 + cells count in UCB products can be overcome by transplantation of two different units. The risk for allogeneic BM and PBPC donors is considered negligible. Lethal and serious side‐effects because of the harvest procedure are rarely reported with an incidence of 1/10 000 and 7·25/10 000, respectively. Granulocyte colony‐stimulating factor (G‐CSF) is widely administered to PBPC donors, but questions have been raised about its safety in respect of development of haematologic malignancies. To evaluate this concern, more long‐term safety data from larger prospective studies are needed. In the therapy with adult stem cells, a genotypic human leucocyte antigen (HLA) class I and class II identity between donor and recipient for the loci HLA‐A, HLA‐B, HLA‐C, HLA‐DR and HLA‐DQ is optimal; for UCB, HLA matching seems to be less important because of the relative low number of mature T cells in cord blood. The influence of other HLA‐linked or not HLA‐linked loci in stem cell transplantation (HLA‐DP, killer cell immunoglobulin receptor, …) is under investigation.

Peripheral blood progenitor cell product contains Th1-biased noninvariant CD1d-reactive natural killer T cells: Implications for posttransplant survival

Bone marrow (BM) Th1 populations can contribute to graft-vs-leukemia responses. Granulocyte/granulocyte macrophage colony-stimulating factor (CSF)-mobilized peripheral blood progenitor cells (PBPC) have become widely accepted alternatives to BM transplantation. T cells coexpressing natural killer cell proteins (NKT) include a CD1d-reactive subset that influences immunity by rapidly producing large amounts of Th1 and/or Th2 cytokines dependent upon microenvironment and disease. There are two types of CD1d-reactive NKT. iNKT express a semi-invariant T-cell receptor-alpha. Other noninvariant CD1d-reactive NKT from BM and liver produce large amounts of interleukin-4 or interferon-gamma, respectively, and within the intestine can be biased in either direction. Recent data suggests that NKT might contribute to clinical benefits of PBPC. To address these issues, we phenotypically and functionally studied PBPC NKT. Similarly to BM, NKT-like cells were common in allogeneic and autologous PBPC, there were relatively few classical iNKT, but high CD1d-reactivity concentrated in NKT fractions. Significantly, PBPC CD1d-reactive cells were relatively Th1-biased and their presence was associated with better prognosis. Granulocyte CSF treatment of BM to yield PBPC in vivo as well as in vitro Th2-polarizes conventional T cells and iNKT. However, granulocyte CSF treatment of BM in vitro produced Th1-biased NKT, providing a mechanism for opposite polarization of NKT from BM vs PBPC. These results suggest distinct Th1 CD1d-reactive NKT cells could stimulate anti-tumor responses from those previously described, which can suppress graft-vs-host disease.

317: Impact of Prophylactic Red Blood Cell Exchange for Prevention of Severe Immune Hemolysis in Pediatric Minor ABO-Mismatched Allogeneic Peripheral Blood Progenitor Cell Transplantation

The presence of minor ABO incompatibility between donor and recipient is common in allogeneic hematopoietic stem cell transplantation (allo-HSCT). Delayed severe immune hemolysis due to donor-derived passenger lymphocytes has been reported in minor and/or bidirectional ABO-mismatched transplants. To evaluate the impact of RBC exchange procedure in pediatric patients on the morbidity and outcome we analyzed 29 pediatric cases undergoing minor ABO-incompatible allo-HSCT from January 2000 to January 2007. First group (RBC exchange) included sixteen patients who underwent prophylactic red cell exchange. Six patients received grafts from HLA identical siblings, ten patients – from HLA matched unrelated donors. Eleven patients received bone marrow transplant (BMT), five patients received peripheral stem cell transplant (PBSC). Patient's age was 10 ± 5.3 years old.Second group (No – RBC exchange) included thirteen patients who did not undergo prophylactic red cell exchange, but the stem cell product was plasma depleted according to the institutional guidelines. Six patients received grafts from HLA identical siblings, three patients from HLA matched unrelated donors, and four patients form unrelated cord blood. Four patients received BMT, five patients received PBSC, four patients received cord blood transplant. Patient's age was 7.6 ± 5.4 years old.No incidence of immune mediated hemolysis was documented in both groups. No patients developed pure red cell aplasia. RBC engraftment was not different in both groups (23.2 ± 4.2 vs. 22 ± 4.2 days). Neutrophil engraftment was similar in both groups (21.0 ± 5.4 vs. 21.02 ± 4.0 days). No significant difference was found among the groups in the incidence of acute graft vs. host disease (GVHD). The incidence of chronic GVHD was insignificantly higher in patients with no RBC exchange (72% vs. 60%). The relapse rate and overall outcome were not influence.In conclusion these results suggest that RBC exchange does not have a significant impact in pediatric patients. Further investigations are required to identify the best clinical transfusion practice in pediatric patients with minor ABO incompatibility. The presence of minor ABO incompatibility between donor and recipient is common in allogeneic hematopoietic stem cell transplantation (allo-HSCT). Delayed severe immune hemolysis due to donor-derived passenger lymphocytes has been reported in minor and/or bidirectional ABO-mismatched transplants. To evaluate the impact of RBC exchange procedure in pediatric patients on the morbidity and outcome we analyzed 29 pediatric cases undergoing minor ABO-incompatible allo-HSCT from January 2000 to January 2007. First group (RBC exchange) included sixteen patients who underwent prophylactic red cell exchange. Six patients received grafts from HLA identical siblings, ten patients – from HLA matched unrelated donors. Eleven patients received bone marrow transplant (BMT), five patients received peripheral stem cell transplant (PBSC). Patient's age was 10 ± 5.3 years old. Second group (No – RBC exchange) included thirteen patients who did not undergo prophylactic red cell exchange, but the stem cell product was plasma depleted according to the institutional guidelines. Six patients received grafts from HLA identical siblings, three patients from HLA matched unrelated donors, and four patients form unrelated cord blood. Four patients received BMT, five patients received PBSC, four patients received cord blood transplant. Patient's age was 7.6 ± 5.4 years old. No incidence of immune mediated hemolysis was documented in both groups. No patients developed pure red cell aplasia. RBC engraftment was not different in both groups (23.2 ± 4.2 vs. 22 ± 4.2 days). Neutrophil engraftment was similar in both groups (21.0 ± 5.4 vs. 21.02 ± 4.0 days). No significant difference was found among the groups in the incidence of acute graft vs. host disease (GVHD). The incidence of chronic GVHD was insignificantly higher in patients with no RBC exchange (72% vs. 60%). The relapse rate and overall outcome were not influence. In conclusion these results suggest that RBC exchange does not have a significant impact in pediatric patients. Further investigations are required to identify the best clinical transfusion practice in pediatric patients with minor ABO incompatibility.

Clinical predictors of alloimmunization after red blood cell transfusion

Development of new red blood cell (RBC) alloantibodies (alloimmunization) is one of the most frequent adverse reactions after an RBC transfusion. Few studies have investigated clinical risk factors for alloimmunization. In this case-control study, the characteristics of all patients in whom alloimmunization occurred for the first time after an RBC transfusion in two hospitals between January 1, 2003, and May 5, 2005, were examined and compared to a randomly selected control group who received RBC transfusions in the same hospitals during the same period without alloimmunization. Odds ratios (ORs) for the association between these characteristics and alloimmunization were calculated and analyzed with a logistic regression model. Eighty-seven cases were found, and 101 controls were selected. Female sex (OR, 1.89; 95% confidence interval [CI], 1.05-3.38), diabetes mellitus (OR, 2.15; 95% CI, 0.91-5.05), solid malignancy (OR, 2.07; 95% CI, 1.00-4.30), and previous allogeneic hematopoietic peripheral blood progenitor cell (PBPC) transplantation (OR, 2.24; 95% CI, 0.64-7.81) were associated most strongly with alloimmunization, whereas lymphoproliferative disorders (OR, 0.33; 95% CI, 0.13-0.81) and symptomatic atherosclerosis (OR, 0.52; 95% CI, 0.25-1.08) were associated with the absence of alloimmunization. All of these associations except for female sex became stronger after adjustment for possible confounders. Female sex, diabetes mellitus, solid malignancy, and previous allogeneic PBPC transplantation seem to be risk factors for alloimmunization, whereas lymphoproliferative disorders and symptomatic atherosclerosis seem to protect against it. Further studies are needed to confirm these associations and investigate underlying mechanisms.

Prophylactic red blood cell exchange for prevention of severe immune hemolysis in minor ABO‐mismatched allogeneic peripheral blood progenitor cell transplantation after reduced‐intensity conditioning

Delayed severe immune hemolysis due to donor-derived passenger lymphocytes is observed in minor and/or bidirectional ABO-mismatched transplants, especially after reduced-intensity conditioning (RIC). The incidence is reported in up to 30 percent of patients and can result in multiorgan failure (MOF) and death. A first group of 32 patients (historical control) underwent RIC followed by allogeneic hematopoietic peripheral blood progenitor cell transplantation at our institution. In 5 of 10 patients with a minor and/or bidirectional ABO-mismatched graft, severe immune hemolysis was observed, leading to death in 3 of them. Therefore, we initiated a protocol with prophylactic red blood cell (RBC) exchange in minor and/or bidirectional ABO mismatch of a second group of patients (study group) and investigated the incidence of hemolysis, transplant-related mortality (TRM), and overall survival (OS) and compared these data with the historical control group. Twenty-two of 80 patients in the study group had a minor and/or bidirectional ABO-mismatched donor. In 20 patients, a prophylactic RBC exchange was performed. Three patients showed mild to moderate citrate reactions, and in 1 patient the procedure had to be stopped because of hypotension. Eighteen of 20 patients engrafted uneventfully, 1 patient rejected his graft, and another 1 showed signs of mild hemolysis. In the minor and/or bidirectional ABO-mismatched setting patients in the study group had a lower risk for TRM at 1 year compared to patients in the historical control group (16% vs. 53%, p < 0.05) and a better 1-year OS (65% vs. 40%, p < 0.05). RBC exchange is a safe procedure, reducing the incidence of delayed severe immune hemolysis and thus the risk of TRM in minor and/or bidirectional ABO-mismatched cases.

Automated programs for collection of mononuclear cells and progenitor cells by two separators for peripheral blood progenitor cell transplantation: comparison by a randomized crossover study

Although automated programs have been increasingly used to collect peripheral blood (PB) progenitor cells (PBPCs), differences among them remain unclear. The automated programs of Amicus (Baxter Healthcare) and Spectra (software Version 6.1, Gambro BCT) apheresis machines were compared in a crossover study. The patients for autologous and donors for allogeneic PBPC transplantation mobilized with granulocyte-colony-stimulating factor were randomly assigned into two groups. PBPCs were collected by the Amicus on the first day and the Spectra on the second of 2 consecutive days in Group I, and the reverse order was used in Group II. Of 39 patients or donors enrolled, 17 reached their collection goal with only one procedure and did not participate in the paired study. Thus, 44 paired procedures of the remaining 22 subjects were evaluated. The product yields of white blood cells (WBCs; p < 0.005), mononuclear cells (MNCs; p < 0.02), and CD34+ PBPCs (p < 0.0002) from patients or donors were higher in the Amicus collections than those in the Spectra collections. The collection efficiencies of WBCs (p < 0.03), MNCs (p < 0.02), and CD34+ PBPCs (p < 0.03) were higher in the Amicus collections. The numbers of contaminating platelets (PLTs) in the Amicus collections were lower than those in the Spectra collections (p < 0.05) with a greater decrease in PB PLT counts after apheresis with the Spectra (p < 0.01). The Amicus had a longer running time than the Spectra for processing similar volumes (p < 0.005). The automated program of the Amicus may be better than that of the Spectra for collecting MNCs and CD34+ PBPCs and avoiding apheresis-induced thrombocytopenia.

Clinical side effects during peripheral blood progenitor cell infusion

There are several side effects which have been reported during the infusion of peripheral blood progenitor cells (PBPCs) either due to the infusion or the content of the infusate. We have evaluated the side effects detected during PBPCs infusion in 194 autologous and 25 allogeneic transplantations. In autologous cryopreserved PBPCs infusion, we detected a total of forty-nine (25.25%) side effect events during and after the infusion period. Forty-six (23.71%) of these side effects were detected during the infusion period including fifteen (7.73%) cardiac side effects, which required stopping the infusion, and thirty-one (15.97%) non-cardiac side effects, which did not require cessation of the infusion. Sinus bradycardia after a minimum of 45 min after completing the infusion was seen in three (1.54%) patients. The median volume, dimethyl sulfoxide (DMSO) and total nucleated cell (TNC) content of the product were found to be significantly higher in patients with side effects compared to the group without any side effects ( P < 0.05). The median volume and DMSO content were found to be significantly higher in patients with cardiac side effects compared to non-cardiac side effects ( P < 0.05). There was no cardiac side effects in patients treated with an infusate containing 100 × 10 9 L −1 leukocytes. We did not observe any infusion-related side effects in patients given allogeneic non-cryopreserved PBPCs. We have concluded that the volume, DMSO and TNC content of autologous cryopreserved PBPCs product are directly related to clinical side effects.

A study of the agreement between patient self‐assessment and study personnel assessment of bleeding symptoms

Clinical trials investigating new platelet transfusion therapies frequently require the assessment of bleeding for the study outcome. These assessments are commonly performed by study personnel and can be time-consuming. The purpose of this study was to assess whether patients were able to reliably assess their bleeding status on a daily basis. Patients admitted to hospital to receive chemotherapy for acute leukemia or to undergo allogeneic peripheral blood progenitor cell transplant were included. Patients were given an introduction to a form for documenting the occurrence of 16 bleeding symptoms. Patients completed this form and were examined daily by a study assessor. A weekly health record review was also performed by a study assessor. The agreement between raters was determined by calculating the raw agreement, chance-corrected agreement, and chance-independent agreement. Thirty-five patients completed 458 assessment forms that were paired with 559 forms completed by a study assessor with 450 matched forms available for analysis (mean, 12.86 per patient). Agreement for most individual bleeding symptoms was high. Thirteen items had agreement greater than 90 percent and all items had agreement greater than 77 percent. The lowest agreement was seen for skin symptoms: petechiae (89.2%), purpura (80.9%), and ecchymosis (77.6%). The negative predictive value of patient self-assessment was high (range, 71.1%-100%) whereas the positive predictive value was lower (range, 0%-86.5%). The reliability was very good between patients and study assessors with the patients reporting excellent negative predictive value and variable positive predictive value.

The effect of hematopoietic progenitor cells’ temperature on cardiac arrhythmias in patients given peripheral blood progenitor cells

Background Infusion of cryopreserved and non-cryopreserved hematopoietic progenitor cells (HPC) is associated with a broad variety of symptoms. In this study, we have investigated infusion-related toxicity regarding temperature of cryopreserved autologous peripheral blood progenitor cells (PBPCs) transplanted in 31 and allogeneic non-cryopreserved PBPCs in 4 patients receiving high dose chemotherapy and stem cells transplantation for hematological malignancies. Study design and method A 24 h ECG-Holter recording system was used to obtain cardiac arrhythmias. Two milliliters HPC were collected from entrance site of venous access to evaluate the temperature of infused HPC. Results We have detected arrhythmias in 17 (48.58%) of our patients before, during and after infusion. Median temperature of the infusat was 21 °C (18–28.2). Arrhythmias during infusion were detected in 8 (22.85%) patients. The temperatures of infused HPCs were not statistically different in group with and without arrhythmias as 22 °C and 21 °C, respectively ( P > 0.05). And also, volume, contents [dimethylsulphoxide (DMSO), red blood cells (RBC), platelet (PLT), and total nucleated cell (TNC)] of product, and rate of infusion speed did not have any effect on arrhythmias. Conclusion As a result of this study, we have concluded that the temperature of HPC does not cause any systemic hypothermia and does not have any relation to arrhythmias detected during infusion.

Granulocyte–colony‐stimulating factor–mobilized prophylactic granulocyte transfusions given after allogeneic peripheral blood progenitor cell transplantation result in a modest reduction of febrile days and intravenous antibiotic usage

It was hypothesized that transfusion of two granulocyte-colony-stimulating factor (G-CSF)-mobilized prophylactic granulocyte components into allogeneic peripheral blood progenitor cell (PBPC) transplant patients during the regimen-related neutropenic interval would result in clinical benefit. HLA-matched sibling PBPC donors (n=151) were biologically randomized based on ABO mismatch to donate granulocyte components (Cohort G) or not donate granulocytes (control group, Cohort C). ABO-matched donors who did not meet other study-specific criteria were reassigned to Cohort C. Feasibility, defined as the proportion of ABO-matched donors who underwent granulocyte collections, was 42 percent (53 of 125). The percentage of patients who developed fever during the initial hospitalization was greater in Cohort C versus Cohort G (82.7% vs. 64.2%; p=0.03). In the interval from when granulocyte transfusions were initially given in Cohort G (Day +3 or Day +5) until neutrophil engraftment, the number of febrile days was less in Cohort G versus Cohort C (median, 0 vs. 1; Mann-Whitney p=0.003). The median number of days of intravenous antibiotics given during the initial hospitalization was less in Cohort G versus Cohort C (9 vs. 11; Mann-Whitney p=0.03), a difference accounted for in the interval from Day +3 or Day +5 to neutrophil recovery. There was no significant difference in length of the initial hospital stay, acute graft-versus-host disease rates, or 100-day survival between the two cohorts. This prospective study demonstrates a modest, but significant, benefit of G-CSF-mobilized HLA-matched prophylactic granulocyte transfusions in neutropenic allogeneic PBPC recipients.