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Transplantation of ex-vivo culture-expanded parental haploidentical mesenchymal stem cells to promote engraftment in pediatric recipients of unrelated donor umbilical cord blood: results of a phase I–II clinical trial

Suboptimal neutrophil and platelet recovery after unrelated donor umbilical cord blood transplantation (UCBT) may be due in part to an impaired microenvironment after intensive chemoradiotherapy. In an attempt to speed hematopoietic recovery, 15 pediatric patients with high-risk acute leukemia were enrolled on a single-institution phase I–II clinical trial in which ex-vivo culture-expanded MSCs from haploidentical parental donors were infused at the time of UCBT. Eight patients received MSCs on day 0, with three patients having a second dose infused on day 21. No serious adverse events were observed with any MSC infusion. All eight evaluable patients achieved neutrophil engraftment at a median of 19 days. Probability of platelet engraftment was 75%, at a median of 53 days. With a median follow-up of 6.8 years, five patients remain alive and disease free. The results of this pilot study show that infusion of ex-vivo culture-expanded haploidentical MSCs into unrelated pediatric UCBT recipients can be performed safely. This encouraging safety profile with haploidentical MSCs supports the investigation of unrelated ‘off the shelf’ allogeneic HLA-mismatched MSC products.

IL-2-based immunotherapy after autologous transplantation for lymphoma and breast cancer induces immune activation and cytokine release: a phase I/II trial

Summary:We determined the safety, immune activating effects, and potential efficacy of i.v. infusion of ex vivo interleukin-2 (IL-2) activated natural killer (NK) cells (part I) or IL-2 boluses (part II) during daily s.c. IL-2 administration following hematopoietic recovery from autologous transplantation. In all, 57 patients with relapsed lymphoma (n=29) or metastatic breast cancer (n=28) were enrolled. In part I of the study, 34 patients were enrolled at three dose levels of ex vivo IL-2-activated NK cells. Lymphaphereses were performed on days 28 and 42 of s.c. IL-2 administration. Following overnight ex vivo IL-2 activation of the pheresis product, the cells were reinfused the following day. In part II, 23 patients were enrolled at three dose levels of supplemental i.v. IL-2 bolus infusions, given on days 28 and 35 during s.c. IL-2 administration. Toxicities were generally mild, and no patient required hospitalization. Lytic function was markedly enhanced for fresh peripheral blood mononuclear cells (PBMNCs) obtained 1 day postinfusion of either IL-2-activated cells or IL-2 boluses. IL-2 boluses transiently increased the levels of IL-6, IFN-γ, TNF-α and IL1-β, with increases in IL-6 and IFN-γ being dose dependent. A total of 37 patients (19 patients with lymphoma, 18 with breast cancer) treated with an optimum dose of post-transplant immunotherapy (defined as having received 1.75 × 106 IU/m2/day of s.c. IL-2 plus at least one of the planned ex vivo IL-2-activated cell infusions/IL-2 boluses) could be matched with controls from the Autologous Blood and Marrow Transplant Registry database. The matched-pairs analysis demonstrated no improvement in disease outcomes of survival and relapse. We conclude that IL-2-activated cells/IL-2 boluses can be safely administered, generate PBMNCs with enhanced cytotoxicity against NK-resistant targets, and increase cytokine levels. With this dose and schedule of administration of IL-2, no improvement in patient disease outcomes was noted. Alternative strategies will be needed to exploit the immunotherapeutic potential of IL-2-activated NK cells.

A randomized trial comparing prednisone with antithymocyte globulin/prednisone as an initial systemic therapy for moderately severe acute graft-versus-host disease

Glucocorticoids remain the standard approach to initial systemic management of acute graft-versus-host disease (aGVHD). For patients refractory to steroids, antithymocyte globulin (ATG) is frequently used as salvage therapy. We decided to test whether the combination of corticosteroids and equine ATG would improve the outcome of initial management of aGVHD, especially in high-risk patients such as recipients of unrelated donor (URD) transplants. One hundred patients with grade II to IV aGVHD having undergone a related or URD marrow transplant were enrolled in the study. Of the patients, 46 were randomly assigned to therapy with prednisone (60 mg/m2 per day x 7 days) and 50 received ATG/prednisone (15 mg/kg ATG bid plus 20 mg/m2 prednisone bid x 5 days, each followed by an 8-week prednisone taper). An intent-to-treat analysis of the overall response at day 42 revealed equivalent complete plus partial response rates of 76% in both the prednisone and ATG/prednisone therapy groups (P > .80). In univariate analysis, patient age, donor type, site of involvement, or aGVHD stage did not influence overall response to therapy (all P > .2). When treatment arms were studied separately, no single clinical feature predicted outcome in either group. Complications were more frequent in the ATG/prednisone arm; patients experienced more infections with cytomegalovirus (44% versus 22%; P = .02) and more frequent pneumonitis, both infectious and noninfectious (50% versus 24%; P < .01). Epstein-Barr virus lymphoproliferative disease was uncommon (4 cases) and comparable in both arms (P = .35). There was no significant difference in survival at day 100, 6 months, and 2 years between the 2 treatment arms. The more intensive immunosuppressive combination of ATG/prednisone failed to improve control of aGVHD and may have affected survival by causing more infectious complications. Combination therapy with ATG should thus be reserved as second-line therapy in the management of aGVHD.

Intra-BM injection to enhance engraftment after myeloablative umbilical cord blood transplantation with two partially HLA-matched units.

The time to neutrophil engraftment for adult patients after myeloablative double unit umbilical cord blood (UCB) transplantation is 23 days when the two units are given i.v. We hypothesized that the intra-BM injection (IBMI) of one of the two UCB units would reduce systemic loss of hematopoietic progenitors and shorten time to neutrophil recovery after myeloablation. Ten patients with a median age of 35 years were transplanted. The unit to be given by IBMI was randomly assigned; the other unit was given i.v. The median infused graft total nucleated cell dose was 3.7 × 107/kg with no difference between i.v. and IBMI units. All patients tolerated the procedure well, and there was no severe adverse event related to IBMI. The median time to neutrophil engraftment and plt recovery >50 000/μl was 21 and 69 days, respectively. In all, 9 of 10 patients engrafted, 5 with the i.v. unit and 4 with the IBMI unit; 7 of 8 evaluable patients developed acute GVHD and 5 of 10 patients died from treatment-related causes. Survival was 47% at 1 year. Despite safety of administration, IBMI of one of two UCB units did not shorten the time to neutrophil engraftment and offers no advantage over conventional double unit transplantation.

New classification of chronic GVHD: added clarity from the consensus diagnoses

The Diagnosis and Staging Working Group of the NIH Consensus Development Project on Criteria for Clinical Trials in chronic GVHD (CGVHD) recently proposed criteria for diagnosis and assessment of overall CGVHD severity. We retrospectively reviewed 54 consecutive patients diagnosed with CGVHD between January 2002 and December 2005 after sibling donor transplant to assess the applicability of the new criteria in prognosticating survival and transplant-related mortality (TRM). A total of 8 patients (15%) were reclassified as late onset/persistent or recurrent acute GVHD (late aGVHD), 15 (28%) had overlap syndrome and 31 (57%) had classic CGVHD. Three-year overall survival was worse in patients with late aGVHD (3-year probability 25% (95% CI 4–56%)) followed by overlap syndrome (3-year probability 87% (95% CI 56–96%)) and CGVHD (3-year probability 75% (95% CI 54–87%)); P=0.001. Among patients with overlap syndrome and CGVHD, a trend towards worse survival was seen in patients with severe disease (3-year probability 57.3% (95% CI 21–82%)) as compared to mild+moderate disease (3-year probability 85.1% (95% CI 68–94)); P=0.1. This analysis, undertaken in a contemporary cohort of related donor recipients, indicates that the consensus guidelines are applicable to this population of CGVHD patients.

Outcome of second hematopoietic cell transplantation in Hurler syndrome

Hurler syndrome (HS) is an autosomal recessive, inherited metabolic storage disorder due to deficiency of lysosomal alpha-L-iduronidase (IDU) enzyme activity. Untreated patients develop progressive mental retardation and multisystem morbidity with a median life expectancy of 5 years. Allogeneic hematopoietic cell transplantation (HCT) can achieve stabilization and even improvement of intellect, with long-term survival. However, children with HS have an increased incidence of graft failure, usually with concomitant autologous marrow reconstitution. Between 1983 and 2000, 71 Hurler children underwent HCT at the University of Minnesota. Of these 71, 19 (27%) experienced graft failure. We report HCT outcomes in all 11 Hurler patients receiving a second HCT at the University of Minnesota. Median age at second HCT was 25 months (range, 16 to 45 months); median time from first HCT was 8 months (range, 4 to 18.5 months). The conditioning regimen consisted of cyclophosphamide/TBI/ATG (n = 8) or busulfan/cyclophosphamide/ATG (n = 3). The source of bone marrow was an unrelated donor in six, matched sibling in four, and mismatched related in one. Five of the 11 grafts were T cell depleted prior to infusion. Overall, 10 of 11 patients showed donor-derived engraftment, of whom three developed grade 3 to 4 acute GVHD. Five of 11 patients are surviving a median of 25 months (range, 2 months to 12 years) with an overall actuarial survival of 50% (95% CI, 27% to 93%) at 4 years. All five show sustained donor engraftment with normalization of IDU activity levels. Three of five evaluable patients demonstrated stabilization of neuropsychological function after second HCT. Currently, allogeneic donor-derived hematopoiesis provides the only chance for long-term survival and improved quality of life in Hurler patients. While graft failure in Hurler patients requires further investigation, a timely second HCT can be well-tolerated and beneficial.Bone Marrow Transplantation (2002) 29, 491–496. doi:10.1038/sj.bmt.1703395

Delayed platelet recovery after allogeneic transplantation: a predictor of increased treatment-related mortality and poorer survival

Delayed platelet recovery (DPR) is common after allo-SCT. Insufficient data on risk factors and association with OS and TRM are available. We conducted a retrospective analysis of all allografts at the University of Minnesota between 2000 and 2005 to characterize the frequency of DPR (platelets <50 000/μL by day 60), risk factors and related complications. A total of 850 patients with hematological malignancies and benign disorders were included. Myeloablative (MA) conditioning was used in 65% of the patients and 45% received umbilical cord blood (UCB) grafts. The 60-day cumulative incidence of platelet recovery was 40% in UCB, 57% in unrelated donor (URD) and 74% in sibling donor. Multivariate analysis confirmed that the variables associated with DPR were MA (versus reduced intensity) conditioning, graft source other than sibling donor, ABO major mismatch, recipient CMV-positive serostatus, the presence of grade II–IV acute GVHD and slower neutrophil recovery. These data demonstrate that DPR is frequent after allogeneic hematopoietic cell transplantation, especially after UCB. DPR is a significant independent risk factor for increased TRM and poorer OS along with HLA-mismatched URD, but not UCB, grade II–IV acute GVHD, old age and advanced disease stage.

Matched-pair analysis of peripheral blood stem cells compared to marrow for allogeneic transplantation

We performed a case-control analysis of 42 patients with advanced leukemia or MDS comparing peripheral blood stem cell (PBSC) with marrow grafts (BMT) from HLA-matched sibling donors. PBSC were mobilized with G-CSF (7.5 μg/kg/day) and yielded a median of 6.7 × 106 CD34+ cells/kg (range, 1.6–15.0) and 2.7 × 108 CD3+ cells/kg (range, 1.1–7.1) vs marrow grafts with a median of 2.0 × 108 nucleated cells/kg (range, 1.8–2.2). Recovery was significantly faster after PBSCT compared to BMT, with a median of 17 (range, 12–26) vs 26 (range, 16–36) days, respectively, to neutrophils >0.5 × 109/l (P < 0.01), and 22 (range, 12–>60) vs 42 (range, 18–>60) days, for platelet recovery (P < 0.01). transplantation of ⩾7 × 106 CD34+ cells/kg accelerated recovery to >20 × 109 l platelets; median 17 days (range, 12–19) vs 23 days (range, 17–36) for those receiving <7 × 106/kg (P = 0.01). PBSC and marrow recipients had similar risks of grades II–IV or III–IV acute GVHD or extensive chronic GVHD (all P > 0.3). At 1 year after PBSCT and BMT, the risk of relapse was 41% and 32%, respectively (P = 0.47), and the probability of survival was 46% and 48%, respectively (P = 0.70). HLA-matched sibling PBSCT resulted in faster neutrophil and platelet engraftment compared to BMT, with no subsequent differences in acute or chronic GVHD, relapse or survival. A minimum of 7 × 106CD34+ cells/kg in PBSC grafts may be required for very rapid platelet engraftment. Bone Marrow Transplantation (2000) 26, 723–728.

Pre-transplant risk factors affecting outcome in Hurler syndrome

Allogeneic transplantation remains the standard of care for patients with Hurler syndrome. As enzyme replacement therapy (ERT) has become available, controversy has emerged in regards to whether the use of enzyme in the peri-transplant period is appropriate. An analysis was performed on 74 patients with Hurler syndrome transplanted at the University of Minnesota between 1990 and 2003, before our use of ERT associated with transplant, with the intention of determining if patients at higher risk during the transplant can be identified based on evaluations and events before transplantation. Age, the presence of hydrocephalus, a history of cardiovascular issues or upper airway obstruction before transplant was not associated with significant differences in survival. In contrast, patients who had a history of lower airway disease, including reactive airway disease or bronchiolitis, or a history of pneumonia, had a significantly inferior outcome based on OS. The risk for serious respiratory complications was also assessed by evaluating the incidence of intubation. Overall, 31% of these patients were intubated. The risk of intubation was higher in older patients and in those with a history of lower airway disease. These findings have implications for the care of patients with high-risk features.

Characterization and management of hypercalcemia following transplantation for osteopetrosis

Autosomal recessive osteopetrosis (OP) is characterized by insufficient osteoclast activity resulting in defective bone resorption and marked increase in skeletal mass and density. OP has been successfully treated with hematopoietic cell transplantation (HCT), secondary to engraftment of donor-derived functioning osteoclasts resulting in remodeling of bone and establishment of normal hematopoiesis. Although hypercalcemia is a common presenting feature of OP, it may be observed following HCT due to engraftment of osteoclasts differentiated from the hematopoietic precursors. To characterize hypercalcemia after HCT—who is at risk, onset, duration and response to treatment—we evaluated 15 patients with OP treated at the University of Minnesota from 2000 to 2009. Hypercalcemia, defined as any single calcium >11.0 mg/100 ml after the first transplant, was found in 40% of patients. Median onset of hypercalcemia was 23 days and the duration was 2–24 days. Hypercalcemia was more common in patients older than 2 years of age at the time of HCT. Treatment with hydration, furosemide and s.c. calcitonin resolved hypercalcemia and resulted in no severe adverse events. In conclusion, hypercalcemia is common in patients with OP within the first 4 weeks after HCT, and more likely in older patients. Isotonic saline, furosemide and s.c. calcitonin were well-tolerated and effective treatments in our study population.