A reduced-toxicity regimen is associated with durable engraftment and clinical cure of nonmalignant genetic diseases among children undergoing blood and marrow transplantation with an HLA-matched related donor.

Blood and marrow transplantation (BMT) is a standard curative therapy for patients with nonmalignant genetic diseases. Myeloablative conditioning has been associated with significant regimen-related toxicity (RRT), whereas reduced-intensity conditioning regimens have been associated with graft failure. In this prospective pilot trial conducted at 2 centers between 2006 and 2013, we report the outcome of 22 patients with nonmalignant genetic diseases who were conditioned with a novel reduced-toxicity regimen: i.v. busulfan (16 mg/kg), alemtuzumab (52 mg/m(2)), fludarabine (140 mg/m(2)), and cyclophosphamide (105 mg/kg). The median age of the study population was 3.5 years (range, 5 months to 26 years). No cases of sinusoidal obstruction syndrome, severe or chronic graft-versus-host disease (GVHD), or primary graft failure were reported. Median time to neutrophil engraftment (>500 cells/µL) and platelet engraftment (>20K cells/µL) were 19 (range, 12 to 50) and 23.5 (range, 14 to 134) days, respectively. The median length of follow-up was 3 years (range, .2 to 6.3). The overall survival rates were 95% at 100 days (95% confidence interval, .72 to .99) and 90% at 6 years (95% confidence interval, .68 to .98). RRT and chronic GVHD are significant barriers to BMT for patients with nonmalignant genetic diseases. This alemtuzumab-based reduced-toxicity regimen appears to be promising with durable engraftment, effective cure of clinical disease, low rates of RRT, and no observed chronic GVHD.

Cytokine and chemokine patterns across 100 days after hematopoietic stem cell transplantation in children.

We mapped the cytokine response to hematopoietic stem cell transplantation (HSCT) by assaying 51 cytokines and chemokines each week for 100 days in 51 children receiving allogeneic (n = 44) or autologous HSCT (n = 7). Assay values were reported as mean fluorescence intensity (MFI). Log transformation converted MFI to clinically relevant measures (ie, pg/mL). We searched for potential markers of transplant complications by using mixed treatment by subject analysis of variance. Global cytokine secretion in HSCT recipients was significantly lower than in concurrent control patients (n = 11). Coincident with the nadir in WBC count, the concentration of many cytokines declined further by the second and third week. All analytes (except monokine induced by gamma interferon [MIG]) subsequently rebounded by week 4 (coincident with engraftment and recovery of WBC count) but often still remained well below control levels. Concurrent with the collective nadir of multiple cytokines, monocyte chemoattractant protein 1 (MCP-1), growth-regulated oncogene alpha (GRO-a), and leptin surged during weeks 2 to 4. High levels of leptin persisted throughout the 100 post-transplant days. Also during weeks 2 to 4, hepatocyte growth factor (HGF) and IL-6 surged in children with complications but not in those without complications. The peak in HGF was more pronounced in veno-occlusive disease (VOD). HGF and IL-6 secretion rose at least 2 weeks before the clinical diagnosis of VOD or graft-versus-host disease (GVHD). From week 4 onward in all groups, the MFI of the cytokine resistin increased to 5 to 15 times above concurrent control. HGF has now emerged in 3 or more biomarker discovery efforts for GVHD (and in our population for VOD as well). HGF (with or without IL-6) should be investigated as a potential predictive biomarker of VOD or GVHD. Alternatively, the hyperinflammatory "signature" provided by a multicytokine assay may be predictive.

Progressive declines in neurocognitive function among survivors of hematopoietic stem cell transplantation for pediatric hematologic malignancies.

Neurocognitive function of pediatric patients is of great concern after hematopoietic stem cell transplantation (HSCT). We evaluated the neurocognitive function of pediatric patients pre-HSCT, 1, 3, and 5 years post-HSCT. All patients had a hematologic malignancy and received therapy to their central nervous system. Healthy siblings were tested as a comparison group. Pediatric patients with a hematologic malignancy did not have a significant decrease in their cognitive function before HSCT compared with their siblings except in areas of academic achievement. Our study population had significant declines in visual motor skills and memory test scores within the first year post-HSCT. By 3 years post-HSCT, there was an improvement in the visual motor development scores and memory scores, but there were new deficits in verbal skills. By 5 years post-HSCT, there were progressive declines in verbal skills (P=0.005), performance skills (0.04), and new deficits seen in long-term verbal memory scores (0.04). On the basis of the raw scores, most of these tests showed that patients had an inability to acquire new skills at a rate comparable to their age-matched healthy peers. However, long-term memory scores showed definite declines. The greatest decline in neurocognitive function occurred in those patients who received cranial irradiation either as part of their initial therapy or as part of their HSCT conditioning. Pediatric patients who received HSCT for hematologic malignancies have neurocognitive deficiencies that are both acute and chronic. Although some patients have acute deficits that appear and improve over time, other patients have progressive declines in neurocognitive function that are chronic.

The effects of Campath 1H upon graft-versus-host disease, infection, relapse, and immune reconstitution in recipients of pediatric unrelated transplants.

Graft-versus-host disease (GVHD) is a cause of serious morbidity and mortality in >50% of recipients of unrelated hematopoietic stem cell transplantation (HSCT). We performed a trial using Campath 1 H pre- and post-HSCT in an attempt to decrease the incidence of GVHD without increasing the risk of infection or relapse. Patients were retrospectively compared to a population of patients who received antithymocyte globulin (ATG) pre- and post-HSCT. Twenty-seven patients were evaluated for this study. Fourteen patients received Campath 1H and 13 patients received ATG. Demographics of patients who received Campath 1H consisted of 9 males and 5 females, with a median age of 13 years (3-17.8 years). Thirteen patients received unrelated bone marrow and 1 patient received unrelated PBSC. Demographics of patients receiving ATG consisted of 9 males, 4 females with a median age of 7.4 years (21 months-19 years). Twelve patients received unrelated bone marrow and 1 patient received unrelated PBSC. Diagnoses were similar between the 2 groups. Patients who received Campath1H received a total dose of 52 mg/m(2) pre-HSCT and 20 mg/m(2) post-HSCT. Patients who received ATG received a total dose of 60 mg/kg pre-HSCT and 100 mg/kg post-HSCT. GVHD prophylaxis and supportive care measures were similar in both groups, including aggressive antimicrobial therapy. There was a significant difference in the incidence of severe (grade III and grade IV) GVHD between the 2 groups (Campath [0 of 14] versus ATG [6 of 13], P = .006). Among the patients who were transplanted for leukemia, there was no significant difference between the 2 groups in terms of relapse (Campath [2 of 14] versus ATG [4 of 9], P = 0.16). The 100-day survival between the 2 groups was not significantly different. Patients receiving Campath 1H had the presence of CD3(+) T cells (>30 cells/mL) in their peripheral blood later than in those who received ATG (64.5 days [Campath 1H] versus 27days [ATG], P = .001). The median time to the development of a normal PHA response occurred later in the Campath 1H arm (283 days[(Campath 1H] versus 88 days [ATG], P = .0001). The median time to an antigen specific response also occurred later in those receiving Campath 1H (365 days [Campath 1H] versus 150 days [ATG], P = .004). There was no significant difference between the 2 groups in terms of fungal or viral infections. Campath 1H is effective in decreasing the incidence of GVHD without increasing the risk of relapse. Although there is a significant delay in immune reconstitution, there was no increase in infectious complications or relapse in recipients of Campath 1H. Further studies are warranted to assess if a lack of difference in infection rates are still demonstrated in larger cohorts.