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Myeloablative conditioning regimens decrease the risk of relapse in pediatric patients undergoing allogeneic hematopoietic stem cell transplant (HCT) for hematologic malignancies, but cause significant toxicities PROCEDURE: This prospective study evaluated the use of a reduced-toxicity, myeloablative regimen with dose-adjusted busulfan, fludarabine, antithymocyte globulin and 400 cGy of total body irradiation in 40 patients 21 years of age undergoing HCT for high-risk leukemias. Busulfan pharmacokinetics were measured to target 4000 μmol*min/day in the first 30 patients; this was increased to 5000 μmol*min/day in the subsequent 10 in efforts to further decrease relapse risk RESULTS: Overall survival at two- and five-years post-HCT was 67% and 51%, respectively. Relapse occurred in 11 patients (28%) at a median of seven months and was the leading cause of death. Transplant-related mortality was 8% and 13% at 100 days and one-year post-HCT, respectively. Trends toward improved survival were seen in patients transplanted for myeloid disease using bone marrow as stem cell source who achieved a busulfan AUC 4000 μmol*min/day with two-year relapse-free survival approaching 80% CONCLUSIONS: This conditioning regimen is safe and effective in patients with high-risk leukemias, particularly myeloid disease. Larger studies are needed to compare its safety and efficacy to other myeloablative regimens in this population.

We enrolled 150 patients in a prospective multi-center study of children with acute myeloid leukemia undergoing hematopoietic stem cell transplant (HSCT) comparing detection of measurable residual (MRD) disease by a “Difference from Normal” flow cytometry (ΔN) approach with assessment of Wilms tumor 1 (WT-1) gene expression without access to the diagnostic specimen. Prospective analysis of the specimens using this approach showed that 23% of patients being screened for HSCT had detectable residual disease by ΔN (0.04–53%). Of those patients who proceeded to transplant as being in morphologic remission, 10 had detectable disease (0.04–14%) by ΔN. The disease free survival of this group was 10% (0–35%), compared to 55% (46–64

Background: Acute graft versus host disease (aGVHD) affects approximately 30–60% of patients after allogeneic hematopoietic stem cell transplantation (HCT) and our ability to predict who develops this complication and their response to treatment is limited. Fecal calprotectin has recently gained popularity as an effective marker of GI inflammation in patients with Inflammatory Bowel Disease (IBD). Methods: Fecal calprotectin and albumin were evaluated as prognostic and predictive markers of aGVHD in 60 adult and pediatric HCT patients. Stool samples were sent for calprotectin quantification prior to starting conditioning, at day 14 post-HCT, at day 28 post-HCT, and at onset of aGVHD ± 2 days. Results: Fecal calprotectin did not differentiate patients with GI-GVHD and non-GI GVHD and did not vary based on severity. However, in patients with steroid-refractory GI aGVHD, significantly higher fecal calprotectin levels were noted. At onset of lower-GI symptoms, steroid refractory patients (n = 3) had a mean fecal calprotectin level of 449 ug/g (range 116–1111 ug/g) and a mean albumin of 1.93 g/dL (range 1.6–2.3 g/dL) compared with a mean fecal calprotectin of 24 ug/g (range 16–31 ug/g) and a mean albumin of 3.3 g/dL (range 2.3–3.9 g/dL) in steroid responsive patients (n = 9) (fecal calprotectin p = 0.032, albumin p = 0.027). Conclusion: Patients with steroid-refractory GI aGVHD had higher fecal calprotectin levels and lower albumin levels than patients with steroid-responsive disease. We recommend further studies to evaluate non-invasive tests with fecal calprotectin in combination with albumin in predicting steroid refractory disease at onset of symptoms to potentially identify patients that may benefit from upfront escalation in GVHD treatment. Keywords: GVHD, Calprotectin, Albumin

Wilms tumor (WT) treatment regimens are curative for more than 80% of patients, but those with relapsed or refractory disease continue to have poor outcomes. High-dose chemotherapy followed by autologous stem cell rescue is often utilized although outcomes remain variable. We report on HD-ASCR outcomes in 24 patients with relapsed or refractory Wilms tumor. Three-year disease free and overall survival are 46% and 60%, respectively, which is similar to those reported for conventional salvage therapies. These outcomes suggest that conventional salvage therapies should be employed for relapsed and refractory WT rather than HD-ASCR.

Current practice for selecting donor units for umbilical cord blood transplant (UCBT) involves matching at HLA-A and HLA-B by low-resolution typing and the HLA-DRB1 allele by high-resolution (HR) typing. We retrospectively studied the impact of HR allele matching at HLA-A, HLA-B, HLA-C, and HLA-DRB1 on transplant-related outcomes in 60 single-unit UCBTs in pediatric patients with malignant and nonmalignant conditions. Five-year overall survival of our cohort was 71% (95% confidence interval, 58-81); 27% experienced primary graft failure. Applying HR typing, donor-recipient mismatch variability increased ranging from 1/8 to 8/8, however, no impact on primary graft failure, graft-versus-host disease or posttransplant infection was observed. UCBTs with ≥6/8 HR matches did have a better overall survival (P=0.04) and decreased transplant-related mortality (P=0.02) compared with

Introduction Myeloablative conditioning (MAC) regimens decrease the risk of relapse in pediatric patients undergoing hematopoietic stem cell transplant (HCT) but cause significant toxicities: transplant-related mortality (TRM) and late effects. Therefore, a MAC regimen that decreases toxicity has the potential to improve overall survival (OS). Busulfan (Bu), fludarabine (Flu), anti-thymocyte globulin (ATG) and 400 cGy of total body irradiation (TBI), a reduced toxicity, MAC regimen was used in pediatric patients. Objectives To evaluate the safety and toxicity of this regimen. Secondary objectives included determining OS at 2 and 5 years, and incidence of relapse and GVHD. Methods We prospectively evaluated 40 patients ≤21 years of age undergoing HCT for high-risk leukemias who received dose-adjusted Bu, Flu, ATG and TBI. Bu pharmacokinetics were measured after a test dose and regimen dose 1 to target AUC of 4000-5000 uMol*min/day. Results Patients were treated between October 2008 and June 2018 (Table 1). OS was 67% and 51% at 2 and 5 years post-HCT, respectively. OS at 2 and 5 years was 70% and 55% for patients with myeloid disease versus 56% and 37% for patients with lymphoid disease, respectively (p=0.18) (Figure 1). Relapse occurred in 11 (28%) at a median of 7 months. TRM was 8% and 13% at 100 days and 1 year post-HCT, respectively. All patients engrafted. >Grade II acute GVHD was seen in 9 (23%); chronic GVHD was seen in 16 (40%). There was no significant impact of age, disease type, donor source or type on HCT outcomes. Long-term toxicities noted were ovarian insufficiency in 8, and short stature, hypothyroidism and learning disabilities in 2 each. Evaluation of Bu AUCs and multivariate analyses are still ongoing. Conclusions Reduced toxicity, MAC regimen was well tolerated with a low incidence of TRM. This regimen shows a trend toward better efficacy in patients with myeloid disease, however larger studies are needed.

Currently, effective pharmacologic treatment to reduce severe oral mucositis (OM) resulting from high-dose myeloablative cytotoxic therapy in the pediatric population is not available. Palifermin has been proven to decrease the incidence and duration of severe OM in adults with hematologic malignancies undergoing hematopoietic stem cell transplantation (HSCT). In the pediatric population, however, data on palifermin treatment are limited. A phase I dose-escalation study of palifermin in pediatric patients with acute leukemias undergoing myeloablative HSCT with total body irradiation, etoposide, and cyclophosphamide was performed to determine a safe and tolerable dose and to characterize the pharmacokinetic (PK) profile and efficacy of palifermin. Twenty-seven patients in 3 age groups (1 to 2, 3 to 11, and 12 to 16 years) and 3 dose levels (40, 60, and 80 μg/kg/day) were studied. There were no deaths, dose-limiting toxicities, or treatment-related serious adverse events. Long-term safety outcomes did not differ from what would be expected in this population. PK data showed no differences between the 3 age groups. Exposure did not increase with increase in dose. The maximum severity of OM (WHO grade 4) occurred in 6 patients (22%), none of whom was in the 80-μg/kg/day dosing group. This study showed that all doses were well tolerated and a good safety profile in all 3 pediatric age groups was seen.

Chronic myeloid leukemia (CML) is a rare malignancy in the pediatric population, accounting for less than 2% of pediatric leukemia.[1] Before the introduction of tyrosine kinase inhibitors (TKI), a...

Background Successful hematopoietic stem cell transplantation (HCT) is curative in primary immune deficiency (PID), but data on post HCT late effects are scarce. We describe outcomes and late effects in PID HCT survivors at 1 year post HCT. Methods Retrospective data analysis was conducted on consecutive PID HCT recipients from Sept 2007-2017 on IRB approved protocol 0707. Outcomes queried included engraftment, graft versus host disease (GVHD), and late effects in survivors. Data review at 2, 5, and 10 years post HCT including analysis of cognitive outcomes and immune reconstitution are ongoing; specifically impact of disease type, age at HCT, and graft source. Results Thirty-nine PID HCT patients received reduced intensity conditioning (RIC) HCT with 1-year overall survival (OS) of 82%. Median age at HCT was 0.5 years (range 0.08 – 17.4 years) and 72% (28/39) were males. Stem cell source was peripheral blood in 72% (19 unrelated, 9 related), umbilical cord blood in 25.5% (10 unrelated), and bone marrow in 2.5% (1 unrelated). Donors were 16 HLA matched and 23 mismatched. RIC regimen was Busulfan AUC 5000 mcmol/L*min x 2 days, Fludarabine 60 mg/m2 × 6 days, rabbit ATG 2mg/kg x 4 days ± Thiotepa 5mg/kg x 1 day. Incidence of > Grade 2 acute GVHD and limited chronic GVHD was 5% (2/39) and 5% (2/39), respectively. Seven patients died due to infection (4), veno-occlusive disease (1), Grade 4 acute GVHD (1), and intracranial hemorrhage (1). Graft failure (GF) rate was 5% (1 primary GF and 1 secondary GF with EBV infection). Donor chimerism (DC) including T cell, was >95% in 60% and those with mixed chimerism had full T cell DC at 1 year post HCT. In 32 survivors, no cardiac, liver, renal, pulmonary abnormalities, or secondary malignancies were noted. Growth was significantly impacted with median height z-scores of -3, with 69% being Conclusion Successful RIC HCT is curative with excellent 1 year OS of 82% with minimal organ toxicities in PID patients; however, significant growth impairment was observed in the majority with some endocrine abnormalities at 1 year post HCT. While further ongoing analysis is imperative, this emphasizes the need for standardized prospective medical surveillance in order to earlier identify post HCT problems systematically and intervene appropriately to improve outcomes in post HCT PID patients.

IV pentamidine for Pneumocystis jiroveci pneumonia prophylaxis in pediatric allogeneic stem cell transplant patients

Hepatic veno-occlusive disease (VOD), also called sinusoidal obstruction syndrome (SOS), is a potentially life-threatening complication of hematopoietic stem cell transplantation (HSCT). Untreated hepatic VOD/SOS with multi-organ failure (MOF) is associated with >80% mortality. Defibrotide has shown promising efficacy treating hepatic VOD/SOS with MOF in phase 2 studies. This phase 3 study investigated safety and efficacy of defibrotide in patients with established hepatic VOD/SOS and advanced MOF. Patients (n = 102) given defibrotide 25 mg/kg per day were compared with 32 historical controls identified out of 6867 medical charts of HSCT patients by blinded independent reviewers. Baseline characteristics between groups were well balanced. The primary endpoint was survival at day +100 post-HSCT; observed rates equaled 38.2% in the defibrotide group and 25% in the controls (23% estimated difference; 95.1% confidence interval [CI], 5.2-40.8;P= .0109, using a propensity-adjusted analysis). Observed day +100 complete response (CR) rates equaled 25.5% for defibrotide and 12.5% for controls (19% difference using similar methodology; 95.1% CI, 3.5-34.6;P= .0160). Defibrotide was generally well tolerated with manageable toxicity. Related adverse events (AEs) included hemorrhage or hypotension; incidence of common hemorrhagic AEs (including pulmonary alveolar [11.8% and 15.6%] and gastrointestinal bleeding [7.8% and 9.4%]) was similar between the defibrotide and control groups, respectively. Defibrotide was associated with significant improvement in day +100 survival and CR rate. The historical-control methodology offers a novel, meaningful approach for phase 3 evaluation of orphan diseases associated with high mortality. This trial was registered at www.clinicaltrials.gov as #.

To determine whether in vivo T-cell depletion, which lowers GVHD, abrogates the antileukemic benefits of myeloablative total body irradiation–based conditioning and unrelated donor transplantation, in the present study, we analyzed 715 children with acute lymphoblastic leukemia. Patients were grouped for analysis according to whether conditioning included antithymocyte globulin (ATG; n = 191) or alemtuzumab (n = 132) and no in vivo T-cell depletion (n = 392). The median follow-up time was 3.5 years for the ATG group and 5 years for the alemtuzumab and T cell–replete groups. Using Cox regression analysis, we compared transplantation outcomes between groups. Compared with no T-cell depletion, grade 2-4 acute and chronic GVHD rates were significantly lower after in vivo T-cell depletion with ATG (relative risk [RR] = 0.66; P = .005 and RR = 0.55; P < .0001, respectively) or alemtuzumab (RR = 0.09; P < .003 and RR = 0.21; P < .0001, respectively). Despite lower GVHD rates after in vivo T-cell depletion, nonrelapse mortality, relapse, overall survival, and leukemia-free survival (LFS) did not differ significantly among the treatment groups. The 3-year probabilities of LFS after ATG-containing, alemtuzumab-containing, and T cell–replete transplantations were 43%, 49%, and 46%, respectively. These data suggest that in vivo T-cell depletion lowers GVHD without compromising LFS among children with acute lymphoblastic leukemia who are undergoing unrelated donor transplantation with myeloablative total body irradiation–based regimens.

The relationship of race/ethnicity with outcomes of umbilical cord blood transplantation (UCBT) is not well known. We analyzed the association between race/ethnicity and outcomes of unrelated single UCBT for leukemia and myelodysplastic syndromes. Our retrospective cohort study consisted of 885 adults and children (612 whites, 145 blacks, and 128 Hispanics) who received unrelated single UCBT for leukemia and myelodysplastic syndromes between 1995 and 2006 and were reported to the Center for International Blood and Marrow Transplant Research. A 5-6/6 HLA-matched unit with a total nucleated cell count infused of ≥2.5 × 10 7 /kg was given to 40% white and 42% Hispanic, but only 21% black patients. Overall survival at 2 years was 44% for whites, 34% for blacks, and 46% for Hispanics ( P = .008). In multivariate analysis adjusting for patient, disease, and treatment factors (including HLA match and cell dose), blacks had inferior overall survival (relative risk of death, 1.31; P = .02), whereas overall survival of Hispanics was similar (relative risk, 1.03; P = .81) to that of whites. For all patients, younger age, early-stage disease, use of units with higher cell dose, and performance status ≥80 were independent predictors of improved survival. Black patients and white patients infused with well-matched cords had comparable survival; similarly, black and white patients receiving units with adequate cell dose had similar survival. These results suggest that blacks have inferior survival to whites after single UCBT, but outcomes are improved when units with a higher cell dose are used.

We report 23 consecutive pediatric patients with MDS who received allogeneic HSCT on IRB approved protocols between 1992 and 2009 at Children's Memorial Hospital (Chicago, IL). Nine patients had de novo MDS, whereas 14 patients had treatment-related MDS. All patients had a documented cytogenetic abnormality, and monosomy 7/7q- was seen in 12 patients (52%). Fourteen of 23 patients received a myeloablative conditioning regimen; RIC regimens were used for the remaining nine. Five patients relapsed post-transplant, including four patients who received RIC transplant and four patients with treatment-related MDS. For the entire group, estimated five-yr RFS and OS were 47% and 50%, respectively. Treatment-related MDS was associated with decreased RFS in comparison with de novo MDS (33% vs. 70%, p = 0.05). Five-year OS rates reached 80% for those with de novo MDS. RIC regimens were associated with decreased three-yr RFS in comparison with myeloablative regimens (22% vs. 68%, p = 0.02). There was no correlation of survival with blast count at diagnosis, IPSS score, cytogenetic abnormality, donor type, or HLA match. Larger series are needed to confirm prognostic factors so that higher-risk patients can be targeted with novel approaches.

Reduced-intensity conditioning regimens have been used extensively in adults with hematologic malignancies. To address whether this is a feasible approach for children with acute lymphoblastic leukemia, we evaluated transplant outcomes in 38 recipients transplanted from 1995-2005 for whom this was their first transplant. The median age at transplant was 12 years, and 47% had performance scores

Summary WT1 gene expression has been proposed as a useful marker of minimal residual disease in leukaemia. Its utility in paediatric haematopoietic stem cell transplantation (HSCT) has not been studied. We studied the prognostic value of WT1 expression in peripheral blood prior to HSCT in 36 children with acute myeloid leukaemia (AML). Samples were obtained 2 weeks pre-transplant to determine the level of WT1 expression. WT1 expression was normalized using K562 cells as a control and a relative value of 0AE 5w as chosen as the cut-off point between high and low WT1 expression. The median level of pre-transplant WT1 expression in the 36 patients was 0AE09 (range 0AE0001–11AE0), with 11patients having WT1 ‡ 0AE5 and 25, WT1

We studied the pharmacokinetic (PK) profile of single daily dose i.v. BU in children who underwent reduced-intensity conditioning (RIC) transplantation. A cohort of 19 patientsor =4 years of age (group 1) and 33 patients4 years (group 2) was studied. Patients received a BU test dose for PK studies, followed by two treatment doses adjusted to target an area under the curve (AUC) of 4000 microM min per day. Patients in group 1 attained a lower AUC as compared to group 2 (3568 vs 4035 microM min). In group 1, 67% patients and in group 2, 84% patients achieved AUC within the targeted range. Stable donor chimerism was achieved in 56% patients in group 1 and 79% in group 2. Eight patients required a second transplantation because of graft failure. Because of the concern that a low AUC adversely affected outcomes, a second cohort of 23 patients followed a modified protocol with a targeted AUC of 5000 microM min. A higher AUC was attained (4825 microM min). Stable donor chimerism was achieved in 91% of patients. Our results show that RIC regimens using two single daily doses of i.v. BU are effective in children, but a targeted AUC of 5000 microM min is recommended.

Genetic mutations of proteins regulating nuclear factor of kappa-light polypeptide gene enhancer in B lymphocyte (NF-kappaB) activation result in heritable diseases of development and immunity. Hypomorphic, X-linked mutations in the IKBKG gene (NF-kappaB essential modulator (NEMO) protein), and hypermorphic, autosomal dominant mutations in the IKBA gene (inhibitor of NF-kappaB (IkappaB)-alpha protein), are associated with a phenotype of immune deficiency and often ectodermal dysplasia (ED-ID). ED-ID predisposes patients to recurrent and life-threatening infections and is typically fatal within the first few years of life. Allogeneic hematopoietic SCT (HSCT) may correct the immune deficiency associated with NEMO or IkappaBalpha mutations, but there is very little published data. We gathered clinical data on three ED-ID patients that had undergone HSCT. Conditioning regimens were variable, as were the stem cell sources. All three patients experienced engraftment difficulties as well as post transplant complications. These cases suggest that patients with immune deficiencies caused by NEMO or IkappaBalpha mutations may have intrinsic barriers to successful engraftment, which require further investigation.

Busulfan (Bu) is widely used in conditioning regimens for infants undergoing allogeneic hematopoietic progenitor cell transplantation (HPCT), but the best approach to administer Bu in this population is still unknown. Here, we report a single-center experience of the use of a test dose to guide dose adjustment of intravenous (i.v.) Bu therapy in infants. Between 2004 and 2013, 33 infants younger than 1 year with nonmalignant conditions received allogeneic peripheral blood or cord blood HPCT after a reduced-intensity conditioning (RIC) regimen consisting of fludarabine, antithymocyte globulin, and 2 single daily doses of i.v. Bu. Pharmacokinetic results of a test dose of i.v. Bu (.8 mg/kg) were used to determine the dose of 2 single daily i.v. Bu regimen doses, adjusted to target an area under the curve (AUC) of 4000 μMol*minute per day in a first cohort (n = 12) and 5000 μMol*minute in a second cohort (n = 21). The mean Bu clearance in our infant patients was found to be 3.67 ± 1.03 mL/minute/kg, and the test dose clearance was highly predictive of the regimen dose clearance. The mean AUC achieved after the first single daily regimen dose was 3951 ± 1239 in the AUC 4000 cohort and 4884 ± 766 for the AUC 5000 cohort. No patient in either cohort developed hepatic sinusoidal obstructive syndrome or seizures attributable to Bu. Primary graft failure occurred in 4 patients and secondary graft failure occurred in 3, predominantly in the AUC 4000 cohort (6 of 7). Among the engrafted patients (n = 28), 16 achieved full donor chimerism and 9 patients attained stable mixed chimerism. Overall survival of patients at 6 years after transplantation was 59.5% for the AUC 4000 cohort and 85.4% for the AUC 5000 cohort, with primary graft failure in the first cohort being a major contributor to morbidity. Logistic regression analysis showed that the risk of graft failure increased significantly if cord blood hematopoietic progenitor cells were used or if total Bu exposure was below 4000 μMol*minute per day for 2 days. The difference in clinical outcomes between the 2 cohorts supports the conclusion that targeting a higher Bu AUC of 5000 μMol*minute per day for 2 days improves donor engraftment in infants with nonmalignant conditions undergoing RIC HPCT without increasing toxicity. Measuring i.v. Bu pharmokinetics using a test dose allows timely adjustment of single daily regimen doses and optimization of total Bu exposure, resulting in an effective and safe regimen for these infants.

We studied 30 pediatric patients with malignant (n = 16) or nonmalignant (n = 14) conditions. The preparative regimen consisted of fludarabine, intravenous (IV) busulfan (Bu) for 2 daily doses, and antithymocyte globulin before stem cell transplantation. A test dose of IV Bu (0.8 mg/kg), anticipated to target an area under the concentration-time curve (AUC) of 800 to 1200 micromol.min, was followed later by 2 daily doses adjusted according to the pharmacokinetics (PK) to target an AUC of 3200 to 4800 micromol.min. The median test dose AUC was 953 micromol.min (range, 439-1315 micromol.min). The median AUC of single daily doses was 3798 micromol.min (range, 1511-7254 micromol.min). PK-based dose modification was required in 20 patients: 12 were adjusted to a higher dose, and in 8 the dose was decreased. Nausea and vomiting were noted in 15 patients. No patient developed hepatic veno-occlusive disease or seizures. Full donor chimerism was attained in 20 patients (mean of 24.5 days), 3 achieved partial chimerism, 5 did not engraft, and in 2 it is too early to assess chimerism. Acute graft-versus-host disease developed in 11 patients, grades I to II developed in 10 patients, and grade III developed in 1. Four patients died of infection and 5 of progressive disease. Thus, PK of a test dose of IV Bu provided information to adjust subsequent daily doses of IV Bu: this resulted in a regimen that was feasible, safe, and convenient for administration to children.

We describe the experience with reduced intensity transplants (RIT) in pediatric patients and review the basis for this approach using adult examples and series of patients. We report the experience with RIT in two pediatric studies.

Infants with acute lymphoblastic leukemia (ALL) have a poor prognosis when treated with standard chemotherapy. A subset of these infants, particularly those with mixed-lineage leukemia (MLL) rearrangements, has a high likelihood of relapse. Hematopoietic stem cell transplantation (HSCT) performed early in first remission may improve outcome. We present the results of 16 patients with infant ALL who were treated with HSCT in first remission. Six patients were ≤6 months of age at diagnosis, 11 had an initial white blood cell count of >50000/μL, and all patients with determinable cytogenetics had a high-risk karyotype [t(4:11) abnormality or other MLL rearrangement]. All patients received 150 cGy of total body irradiation for 8 doses (1200 cGy). Fifteen of 16 patients received etoposide at 1000 mg/m2 as a continuous infusion over 24 hours and cyclophosphamide at 60 mg/kg/d for 3 days. Eight patients received HSCT from an HLA-identical sibling, and 8, from unrelated cord blood. Twelve (75%) patients remain long-term survivors (median follow-up, 4.7 years). Two patients, 1 of whom had minimal residual disease at HSCT, died after relapse following HSCT. Two patients died of transplant-related causes. The HSCT was well tolerated; 15 patients achieved neutrophil engraftment at a median of 16 days. Acute and chronic graft-versus-host disease were minimal in these patients. These results support the use of HSCT in the treatment of infant ALL, especially when used as consolidation in first remission. The risk of relapse seems to be decreased with this approach. Further work is being performed to determine the long-term effects from this therapy.

Wilms' tumor 1 (WT1) gene expression is seen in a significant number of cases of human neoplasia; however, the mechanism of action remains to be clarified. We hypothesized that WT1 gene is a surrogate marker of proliferation in normal hematopoietic cells and leukemias. While we and others have recognized its value as a tool for the detection of minimal residual disease (MRD), the objective of this study was to confirm our hypothesis regarding normal.Samples from healthy donors (n=16) and UC blood (n=9) were cultured in Methocult for 21 days. Colonies were analyzed on days 7, 14 and 21 by RT-PCR for WT1 gene expression. Our positive controls were samples from patients with leukemia (n=91). Negative controls were from normal volunteers without stimulation (n=26).Results showed a statistically significant difference (P0.0001) between cultured groups, with the highest level of WT1 gene expression in the positive controls and on day 14, when cells are at their maximal proliferation.In conclusion, WT1 gene expression in the proliferating colonies was highest on day 14, although less than in leukemia samples, confirming our hypothesis that WT1 gene is a surrogate marker of proliferation, not only in leukemogenesis but also, to a lesser degree, in normal cell proliferation.

The use of peripheral blood stem cells (PBSC) for allogeneic transplants in adults has greatly increased. This trend is reflected in pediatrics, where healthy children increasingly are donating PBSC or donor lymphocyte infusion (DLI) via apheresis for use by ill siblings. There is a potential concern that the risks of PBSC collection may differ for pediatric donors. However, no large studies have assessed safety issues in this population. To address this need, we reviewed 218 (213 PBSC, five DLI) collections in 201 normal pediatric donors (8 months to 17 years, median 11.8 years) at 22 institutions in the Pediatric Blood and Marrow Transplant Consortium. Donors received a median of 4 days of growth factor, and mean collection yield was 9.1 x 10(6) CD34+ cells/kg recipient weight. Younger age, days of apheresis, and male gender predicted increased yield of CD34+ cells/kg donor weight. Growth factor-induced pain was mild and reported in less than 15% of patients. Most donors

Purpose To investigate whether high-dose therapy with hematopoietic stem-cell rescue (HSCR) will improve survival for patients with relapsed Wilms’ tumor. Patients and Methods Thirteen children with relapsed Wilms’ tumor were treated with one or two cycles of high-dose chemotherapy (HDT) followed by autologous HSCR. Twelve of 13 patients received reinduction chemotherapy before HDT and HSCR. The median age at diagnosis was 4.8 years, and the median time to relapse was 12 months. The histology was favorable in 12 of 13 patients. The ablative regimens included: (1) thiotepa (TT)/cyclophosphamide (CTX)/carboplatin (CP; n = 2); (2) TT/CTX (n = 5); (3) TT/etoposide (ETP; n = 1); and (4) CP/ETP/CTX (n = 1). Four patients received two cycles of HDT and HSCR. Cycle 1 consisted of CP/ETP/CTX, and melphalan/CTX were used in cycle 2. Results Seven of 13 patients are alive without evidence of disease, with a median follow-up of 30 months. The 4-year estimated event-free survival (EFS) rate is 60% (95% CI, 0.40 to 6.88), and the overall survival (OS) at 4 years is 73% (95% CI, 0.40 to 6.86). There was no transplant-related mortality. All patients engrafted to an absolute neutrophil count 500/μL at a median of 13 days (range, 8 to 62 days) and had an unsustained platelet count > 20.0μ at a median of 16 days (range, 10 to 202 days). Conclusion Our results suggest that HDT with HSCR is an effective treatment for patients with Wilms’ tumor who experience relapse.

Patients with acute myeloid leukemia (AML) who relapse after hematopoietic stem cell transplantation (HCT) have dismal outcomes. Our ability to predict those at risk for relapse is limited. We examined chimerism trends post-HCT in 63 children who underwent HCT for AML or myelodysplastic syndrome (MDS). Mixed T-cell chimerism at engraftment and absence of chronic graft versus host disease (cGVHD) were associated with relapse (P = 0.04 and P = 0.02, respectively). Mixed T-cell chimerism at engraftment was predictive in patients without cGVHD (P = 0.03). Patients with engraftment mixed T-cell chimerism may warrant closer disease monitoring and consideration for early intervention.

Unrelated donor marrow transplantation is associated with an increased incidence of graft-versus-host disease (GVHD) compared with sibling donor transplants. Forty-one patients undergoing unrelated donor transplants were treated with a GVHD prophylaxis regimen that consisted of continuous infusion cyclosporine from day -1 to 100 days post transplant along with nifedipine, glucocorticoids and short-course methotrexate. The regimen was well-tolerated in this cohort with mostly high risk disease. Fifty-one percent of patients developed acute GVHD, which was grade III-IV in 22% of patients. Six of 22 patients at risk for chronic GVHD developed extensive chronic GVHD, five of whom were adults. In patients18 years of age, there was a40% chance of 2 year disease-free survival. Use of continuous infusion cyclosporine with nifedipine as an immunosuppressant and protectant against cyclosporine-induced toxicities in unrelated donor transplants is well-tolerated, and results in acute GVHD incidence favorable to that reported with bolus cyclosporine.

The role of tandem high-dose chemotherapy (HDC) with autologous peripheral hematopoietic progenitor cell rescue (APHPCR) in patients with Ewing Family Tumors (EFT) is controversial. We initiated treatment for eight consecutive patients with high-risk EFT with HDC and APHPCR from 1992 to 2003. There were no treatment related deaths. Four patients remain in complete remission, including three who did not undergo local therapy to bone at either the primary or metastatic sites. Our experience has shown that treatment of EFT patients with tandem HDC with APHPCR may benefit a subgroup of high-risk patients in whom optimal local therapy is not possible. Pediatr Blood Cancer 2007;49:196–198. © 2007 Wiley-Liss, Inc.

One hundred and thirty-six patients autografted for relapsed or refractory non-Hodgkin's lymphoma (NHL) were evaluated to assess long-term event-free survival and to identify important prognostic factors. High-dose therapy consisted primarily of carmustine (BCNU), etoposide, cytarabine, and cyclophosphamide (BEAC) followed by unpurged autologous stem cell rescue. The 5-year Kaplan-Meier event-free survival (EFS) for the entire cohort was 34% (95% confidence interval: 24-44%) with a median follow-up of approximately 3 years (range 0-7.5 years). For patients entering with minimal disease (defined as all areas < or = 2 cm), the 5-year EFS was 40 vs 26% for those entering with bulky disease (P = 0.0004). In the multivariate analysis, minimal disease on entry and administration of involved-field XRT post-transplant were significantly associated with improved EFS; the latter association was observed mainly in the cohort of patients with bulky disease. The overall 100-day treatment-related mortality rate was 4.4% (3% for the last 71 patients). New strategies are needed to reduce the high rate of relapse (50-60%) following auto-transplantation for relapsed or refractory NHL.

We report 23 consecutive pediatric patients with MDS who received allogeneic HSCT on IRB approved protocols between 1992 and 2009 at Children's Memorial Hospital (Chicago, IL). Nine patients had de novo MDS, whereas 14 patients had treatment-related MDS. All patients had a documented cytogenetic abnormality, and monosomy 7/7q- was seen in 12 patients (52%). Fourteen of 23 patients received a myeloablative conditioning regimen; RIC regimens were used for the remaining nine. Five patients relapsed post-transplant, including four patients who received RIC transplant and four patients with treatment-related MDS. For the entire group, estimated five-yr RFS and OS were 47% and 50%, respectively. Treatment-related MDS was associated with decreased RFS in comparison with de novo MDS (33% vs. 70%, p = 0.05). Five-year OS rates reached 80% for those with de novo MDS. RIC regimens were associated with decreased three-yr RFS in comparison with myeloablative regimens (22% vs. 68%, p = 0.02). There was no correlation of survival with blast count at diagnosis, IPSS score, cytogenetic abnormality, donor type, or HLA match. Larger series are needed to confirm prognostic factors so that higher-risk patients can be targeted with novel approaches.

Purpose To determine the response, toxicity, and survival for children with progressive or recurrent medulloblastoma and germinoma using a single myeloablative course of chemotherapy supported by autologous hematopoietic stem cells. Patients and Methods Subjects were in second remission or had minimal residual disease at the time of study entry. The conditioning regimen consisted of cyclophosphamide 6,000 mg/m2 plus melphalan 180 mg/m2. Results Twenty-nine evaluable pediatric patients were accrued. The most frequent major toxicities were myelosuppression, infections, and stomatitis, but no toxic deaths were recorded. Best responses were: CR = 6, CCR = 13, PR = 6, SD = 2, and PD = 2. There were 6 medulloblastoma and 3 germinoma survivors with a median follow-up of 7.5 years (range = 2.8–10). Two germinoma survivors received radiotherapy after autografting for presumptive progressive disease. Conclusion Myeloablative chemotherapy consisting of cyclophosphamide and melphalan was tolerable in the relapsed brain tumor setting with 19/29 cases achieving CR or CCR status and 9/29 becoming long-term survivors. Pediatr Blood Cancer 2008;51:675–678. © 2008 Wiley-Liss, Inc.

High risk/recurrent CNS tumors have a poor prognosis. We studied tandem high dose chemotherapy (HDC) with hematopoietic progenitor stem cell rescues (HPCR) as potentially curative therapy. Twenty-four patients (mean age 6.8 years) were enrolled, 19 underwent HDC/HPCR. Diagnoses were medulloblastoma (n = 9), germ cell tumor (n = 4), high grade astrocytoma (n = 2), supratentorial PNET (n = 1), pineoblastoma (n = 2), or papillary meningioma (n = 1). Cytoreduction regimen #1 consisted of carboplatin (500 mg/m(2)) x 3 days, etoposide (250 mg/m(2)) x 3 days, and thiotepa (300 mg/m(2)) x 3 days. Patients without progression or excessive toxicity (n = 11), received regimen #2 with melphalan (60 mg/m(2)) x 3 days and cyclophosphamide (1,500 mg/m(2)) x 4 days. Projected overall/event-free survival for the 19 patients was 51/37% and 34/28% at 1 and 5 years, respectively. Toxicity was significant with six treatment related deaths including four with veno-occlusive disease. This regimen of sequential HDC/HPCR in high risk/recurrent CNS tumor patients is not feasible due to toxicity.

Stevens-Johnson syndrome (SJS) is not typically reported following hematopoietic stem cell transplant (HSCT). The most severe form of SJS, which is toxic epidermal necrolysis (TEN) has been reported following HSCT, albeit very rarely. We describe a case of Mycoplasma-associated SJS following HSCT. While this association is commonly reported in previously healthy children, it has not been reported in patients following HSCT.

The authors have studied the sequential events in the process of vertebral metastasis that result in spinal cord compression. Different tumor cell lines were injected into the systemic arterial circulation of syngeneic or nude mice, and they were killed at timed intervals after injection or when they became paraplegic. The following observations were made. The tumor cells lodged and grew in the hematopoietic bone marrow of the vertebrae. Cancer cells in the vertebral marrow cavity invaded into the spinal canal through the foramina of the vertebral veins rather than destroying the cortical bone. Tumor cell lines that grew in an infiltrative fashion migrated toward a posterior location in the spinal canal, and compressed the spinal cord from a posterior direction. Tumor cell lines that grew as compact tumors formed a tumor mass at the same location from which the cells emerged from the vertebra, and compressed the cord predominantly from an anterior direction. Radiographic evidence of vertebral metastasis was a late event, and commonly associated with significant compression of the cord and extraosseous tumor. These experimental findings may help to establish better diagnostic and treatment strategies for patients with metastatic disease of the spine.

Weight loss and malnutrition are major problems in patients with chronic graft-versus-host disease (GVHD). In adults, low body mass index (BMI) is a predictor for mortality; however, weight loss and BMI have not been studied in pediatric chronic GVHD. A retrospective study on 18 children with extensive chronic GVHD was completed. Median age at SCT was 12.3 (range 0.6-23) years; age at chronic GVHD diagnosis was 12.5 (1-23) years. Patients with multiorgan involvement had a mean maximal decrease in BMI of 20.9% and most dropped below 10th percentile in expected weight-for-age. This change in BMI not only indicates a significant decrease in weight but often a plateau in stature. In contrast, patients with one organ system involved had a mean maximal decrease in BMI of 5% and did not fall below 10th percentile. All patients with multiorgan involvement required salvage therapy beyond steroids and CSA. Three patients died due to complications of chronic GVHD. Weight loss and malnutrition (as reflected by a decrease in BMI) are clinically significant issues in children with multisystem chronic GVHD. Weight loss is likely another systemic manifestation of the disease and may contribute, along with other factors such as increased immunosuppression and infection, to increased mortality in this group.

Background: The incidence of venous thromboembolism (VTE) is rising in critically ill children. It is one of the most common hospital acquired complications and the use of thromboprophylaxis remains controversial. Exposure to risk factors including central venous lines, infection/inflammation and prolonged immobilization increases the risk of VTE while underlying coagulopathy, thrombocytopenia, requirement of invasive procedures, organ failure or medications increase the risk of bleeding. Therefore, understanding these risk factors in various subsets of critically ill children is vital to develop VTE prevention strategies. Since Hematopoietic Stem Cell Transplant (HSCT) recipients comprise a subset of patients at high risk of developing VTE due to exposure to the risk factors above, we explored the trends and risk factors for VTE in children undergoing HSCT using a national administrative database during the past decade. Methods: ThePediatric Health Information System (PHIS) database was queried using the ICD-9-CM codes to identify children

Hematopoietic stem cell transplantation (HSCT) is a potentially curative therapy for severe primary immunodeficiency diseases (PID), but it is still unclear what is the optimal transplant approach. To help answer this question, the stem cell transplant team at Ann & Robert H. Lurie Children's Hospital of Chicago (formerly Children's Memorial Hospital) evaluated the risks and benefits of a reduced-intensity conditioning (RIC) transplant approach for treatment of severe PID. Between 2000 and 2013, 42 children with severe PID were treated with allogeneic HSCT following a RIC regimen consisting of fludarabine (30mg/m2/day x 6), rabbit anti-thymocyte globulin (once daily x 4), and intravenous busulfan (once daily x 2). Total busulfan exposure, as measured by the plasma concentration-time area-under-the-curve (AUC), was targeted individually for each patient at 4000 µM*min/day in an earlier cohort (n=14), and 5000 in a later cohort (n=28). Patients were treated in an ambulatory setting and were hospitalized only for specific medical or social reasons. There were 31 male and 11 female patients. The median age at the time of transplant was 8.2 months (range 1 month-17.4 years). The median weight was 7.6 kg (range 2.5-81.5 kg). Patients were diagnosed with severe combined immunodeficiency (n=17), Wiscott-Aldrich syndrome (n=7), hyper-IgM syndrome (n=5), major histocompatibility complex II deficiency (n=3), X-linked lymphoproliferative disease (n=3), NEMO syndrome (n=2), Omenn syndrome, reticular dysgenesis, Chediak-Higashi syndrome, IPEX (immune dysregulation, polyendocrinopathy, enteropathy, X-linked) syndrome, and IPEX-like syndrome (n=1 each). Fourteen patients had related donors and 28 had unrelated donors. Twenty-eight patients received peripheral blood HSC, 12 received cord blood, and 2 received bone marrow as the source of HSC. All patients tolerated the conditioning regimen with minimal nausea, vomiting, or pain. No severe mucositis, sinusoidal occlusion syndrome, seizure, grade III/IV acute GVHD or extensive chronic GVHD were seen. In most patients, the engraftment was rapid, with ANC ≥ 500 at a median of +15 days post-transplant, following a nadir at day +10 with a median ANC nadir of 60. In the AUC 4000 cohort, 2 patients (14%) developed primary graft failure and 2 patients (14%) developed immune-mediated secondary graft failure; in the AUC 5000 cohort, 2 patient (7%) developed primary graft failure and 1 patient developed secondary graft failure after primary EBV infection. Two patients died from complications associated with primary graft failure, 2 from complications caused by EBV infections, and 2 from complications related to their underlying diseases in the early post-transplant period. Kaplan–Meier analysis shows overall and event-free survival rates of 81.9% and 73.6%, respectively, at a median follow-up of 4.3 years. Most engrafted patients have stable donor chimerism over time. At a mean of 3.5 years post-transplant, the median donor chimerism in total white blood cells was 97% and the first and third quartiles were 77% and 99%, respectively. Engrafted patients demonstrated robust immune reconstitution with B and T cell counts normalized by 3 months and 9 months post-transplant, and CD45RA+ naive T cells by 1 year. Between 1 to 4 years post-transplant, the median absolute CD4+, CD8+ and CD19+ cell counts were 1388, 976 and 720 per mm3, respectively, percentage of CD45RA+ naive CD4 and CD8 cells were 68% and 81%, and endogenous IgG and IgM levels were 840 and 97 mg/dL. T cells showed regular responses to antigen and mitogen stimulation and exhibited normal TCRVβ repertoires. Endogenous IgG levels returned to normal by day +100, and no intravenous immunoglobulin infusion was required after day +100 in all but 1 patients. Positive vaccine-specific antibody responses were seen in patients after reimmunization at 12-24 months post-transplant. Clinically, patients have normal growth and development and do not exhibit increased susceptibility to infection. Our data showed that HSCT after RIC offers an optimal treatment for severe PID by providing robust post-transplant immune reconstitution while minimizing side effects. To reduce the risk of graft failure, we recommend a targeted busulfan AUC of 5000 µM*min/day for 2 days. Disclosures No relevant conflicts of interest to declare.