B-cell depletion abrogates immune mediated cytopenia and rejection of cord blood transplantation in Hurler syndrome.

Umbilical cord blood is the preferred donor cell source for children with Inherited Metabolic disorders undergoing Hematopoietic Cell Transplant (HCT), and its use has been associated with improved "engrafted survival" and higher donor chimerism compared to other cell sources. However, as in other pediatric cord blood transplants for non-malignant disease, immune-mediated cytopenia and primary graft failure limit its use, and the latter remains the commonest cause of death following cord blood transplant for non-malignant disease. We have previously shown an association between immune-mediated cytopenia and graft failure in inherited metabolic diseases suggesting that both immune-mediated cytopenia and graft failure could be mediated by antibodies from the residual recipient B cells. Since rituximab is effective in depletion of B cells and management of refractory immune-mediated cytopenia following HCT, we have added rituximab to the conditioning regimen. We studied 57 patients in 2 centers who received myeloablative conditioning for cord blood transplant in Hurler syndrome, and report a significant improvement in event-free survival with reduced incidence of graft failure and without any evidence of immune-mediated cytopenia in those patients that had received rituximab.

Changes in the incidence, patterns and outcomes of graft failure following hematopoietic stem cell transplantation for Hurler syndrome.

Hematopoietic stem cell transplantation (HSCT) is the standard of care in children with Hurler syndrome (HS) as it is the only therapy that can arrest disease progression. We examined the incidence, patterns and outcomes of graft failure in all HS children undergoing first HSCT at the Royal Manchester Children's Hospital or the University of Minnesota Children's Hospital from 1983 to 2016. Implementation of busulfan pharmacokinetic monitoring started in 2004 in both institutions. Two hundred and forty HS children were included in this analysis (historical era (pre-2004), n=131; current era (post 2004), n=109). The proportion of patients with graft failure was significantly lower in the current era compared with the historical era (37.2% vs 10.1%, respectively). Of 49 patients with graft failure in the historical era, 1 had aplasia and 48 had autologous reconstitution. All the 11 graft failures of the current era occurred in recipients of cord blood transplants (7 aplasia and 4 autologous reconstitution). The outcomes of second transplant in these patients has improved, with 89% of such patients alive and engrafted in the current era compared with 58% in the historical era. The pattern of graft failure has changed from autologous reconstitution, likely secondary to inadequate myelosuppression in the historical era, to aplasia in the current era, likely due to imperfect immunosuppression.

In vivo T-cell depletion using alemtuzumab in family and unrelated donor transplantation for pediatric non-malignant disease achieves engraftment with low incidence of graft vs. host disease.

In vivo T-cell depletion, using alemtuzumab therapy prior to SCT, can reduce the incidence of GVHD. This treatment has a potential to delay immune reconstitution resulting in increased morbidity due to viral illnesses. We retrospectively analyzed data on all pediatric patients with non-malignant disorders who received alemtuzumab-based conditioning regimens in our center over the last 10 yr (n = 91). Our data show an OS of 91.2%. The incidence of acute (grade 2-4) GVHD was 18.7% and that of chronic GVHD 5.5%. Viremia due to adenovirus, EBV and CMV was seen in 19.8%, 64.8% and 39.6% patients, respectively, with only two deaths attributed to viral infection (adenovirus). Chimerism level at three month was predictive of graft outcome. Nine patients, who had graft failure after first SCT, were salvaged with a second SCT using RIC and same donor (if available). Based on these results, we conclude that the use of in vivo T-cell depletion is safe, achieves good chimerism and does not lead to increased morbidity and mortality due to viral infections. It is associated with a reduced incidence of chronic GVHD.

Extracorporeal photopheresis for treatment of adults and children with acute GVHD: UK consensus statement and review of published literature.

Extracorporeal photopheresis (ECP) has been used for over 20 years to treat acute GVHD (aGVHD) and chronic GVHD. Evidence on the efficacy of response in aGVHD has continued to accrue and data suggest that there is a good response and prolonged survival in both children and adults with grade II-IV aGVHD. Unlike chronic GVHD where treatment schedules are typically one or two times monthly for 12-18 months, patients with aGVHD respond rapidly to an intense weekly treatment schedule for 8 weeks, typically allowing steroids to be discontinued without flare-ups of aGVHD. Maintenance ECP therapy is generally not required. Many centres across Europe and United States treat aGVHD with ECP as second-line therapy and responses are excellent in a subset of patients. Unlike other second-line therapies, ECP is not immunosuppressive and has no reported drug interactions. Importantly, ECP does not have a negative impact on the graft-versus-malignancy effect of the transplant. This statement aims to select those patients most likely to respond to treatment and summarises treatment and monitoring schedules for the management of aGVHD in adult and paediatric patients to ensure the correct patients are treated with the optimal protocol for efficacy.

Chronic norovirus infection in pediatric hematopoietic stem cell transplant recipients: a cause of prolonged intestinal failure requiring intensive nutritional support.

Norovirus infection is a major cause of nonbacterial gastroenteritis. In immunocompetent individuals the illness caused by norovirus is mostly self limiting. Excretion of norovirus has been reported to be prolonged in the immunocompromised including adult HSCT recipients. We report a case series of 13 children who received HSCT and required prolonged parenteral and enteral nutrition due to severe gut dysfunction accompanying protracted norovirus excretion that was monitored by RT-PCR. The median duration of viral excretion was 150 days (range 60-380) and the eventual clearance of norovirus from feces was closely associated with donor T cell recovery in the peripheral blood. There was no disease manifestation beyond the gut but the severity and length of norovirus associated illness suggests that HSCT should be delayed where possible in patients excreting the virus prior to conditioning therapy.

CD34 progenitor cell subset analyses in normal human bone marrow and marrow harvested after intermediate-dose chemotherapy.

Previous attempts to characterize harvested marrow and peripheral blood stem cell (PBSC) in order to predict time to and quality of engraftment post autologous bone marrow transplant (autoBMT) have included use of in vitro colony forming unit (CFU) assays. These assays are hampered by interlaboratory variability and are not uniformly predictive. CD34 quantification by flow cytometric technique has also been used to assess the quality of harvested marrow and PBSC. However, a lack of standardization has hampered direct comparison of published reports. We sought to characterize these early lineage-committed CD34+ progenitor cells from non-ficolled harvested marrow with six progenitor cell (PC) panels containing CD34 antibody plus two additional early lineage markers, using multiparameter flow cytometry. The specific gating technique including simultaneous CD34-PE vs. side scatter and forward vs. side scatter, was verified using morphologic analyses of sorted CD34+ cells. An ungated file was initially acquired to assess total CD34+ content. A second file using a CD34 threshold was then acquired to resolve lineage-committed subsets. The % CD34+ cells as well as cells/microliter of bone marrow was calculated using cell counts at the time of marrow harvest. Bone marrow (mean total cell dose = 3.8 x 10(5)/kg), obtained from 42 normal donors for allogeneic transplantation was first analyzed. CD34+ cells comprised a mean 1.3% of non-ficolled marrow, with 328 CD34+ cells/microliter, and mean CD34+ cells collected was 4.8 x 10(6)/kg. While no significant differences in total cells harvested nor proportion of CD34+ cells was found, a significant decrease in CD34 cells/microliter (= 233, P = .0012) was found in cancer patients. The percentage of CD19+ and CD38+ progenitor cells was significantly increased, while CD5+ and CD71+ cells were decreased. The proportions of all other early lineage-committed CD34 subsets were not different. Measurement of lineage-committed CD34 progenitor cells is a useful technique to characterize harvested marrow and PBSC, and may be applied to predict time and quality of engraftment post ablative conditioning regimens.

[Could a contest encourage smokers from an unfavorable environment to abstain from smoking for at least six weeks?]. / Un concours peut-il inciter des fumeurs d'un milieu défavorisé à s'abstenir de fumer pendant six semaines?

A contest to encourage smokers to quit and to remain nonsmokers for at least six weeks was held in a low income neighbourhood in Montreal. The contest was one of many activities for a multifactorial community-based heart health promotion program. The objective of this article is to describe the intervention and its evaluation and to reflect on its relative successes. Thirty-one persons registered for the contest, seven stopped smoking during the six-week contest, and six persons remained abstinent two weeks after the end of it. Concrete recommendations regarding the contest and implementation of a smoking cessation program are discussed.