Acute graft-versus-host disease in children

Outcomes of high-grade gastrointestinal graft-versus-host disease posthematopoietic stem cell transplantation in children

We explored the clinical course of acute high-grade gastrointestinal graft-versus-host disease in children in a single center. This was a retrospective analysis of 28 pediatric patients who presented with a clinical diagnosis of stage III and IV acute graft-versus-host disease (aGVHD) of the gastrointestinal system (GIS). Generally, skin involvement was the initial manifestation of aGVHD that began in the first 3 weeks of hematopoietic stem cell transplantation (HSCT); on the other hand, GIS involvement predominated after the second week of HSCT. Reported adult data show a survival rate of only 25%; however, our study showed more favorable outcomes in children with a survival rate of 55%. We monitored levels of albumin and immunoglobulin G and observed low levels overall during treatment of unresponsive patients, although only albumin levels were shown to be significantly different. We observed a significant increase in mortality with the use of antithymocyte globulin in GIS aGVHD, although antithymocyte globulin used for graft-versus-host disease prophylaxis had no demonstrable effect on GIS aGVHD mortality. Whether the significantly lower GIS aGVHD mortality among the children recruited in our study than among their historical adult counterparts is a primary result of the specific attributes of the pediatric GIS, or whether it originated from HSCT kinetics remains to be determined by future studies.

Graft-versus-host disease in paediatric solid organ transplantation: A review of the literature

GvHD is a rare and serious complication of organ transplantation. The literature is sparse following solid organ transplantation. The aim of this report was to review the literature of GvHD in paediatric solid organ transplantation. We searched PubMed for English-language full-text manuscripts between 1990 and 2015 for eligible studies. A total of 28 publications were found pertaining to paediatric GvHD following solid organ transplantation. GvHD had a mean incidence of 11% (range 8.3-13.4%) following SBTx and 1.5% following liver transplantation. Where described, the most common sites for presentation of GvHD were the skin (87%), the native GI tract (43%), the lungs (7%), the eyes (4%), HA (4%), and the kidneys (1%). Diagnosis was confirmed with biopsy (93%) and/or chimerism (41%). Treatments used include steroids (80%), of which 75% showed partial or complete resolution. Mortality was 33.3% (range 0-100%). Novel therapies include ECP and MSC therapy. GvHD is a rare but serious disease with high mortality. Novel therapies may offer hope in the future, but currently there is limited evidence for their efficacy in the context of intestinal or liver transplantation.

Unmanipulated haploidentical haematopoietic stem cell transplantation for children with severe aplastic anaemia

Haploidentical haematopoietic stem cell transplantation (haplo-HSCT) used to be a third-line treatment option for childhood severe aplastic anaemia (SAA). We conducted this retrospective study of 36 children (38 transplants) who received haplo-HSCT from human leucocyte antigen (HLA)-mismatched related donors between July 2002 and November 2013 at five HSCT centres in China, including 17 cases that were 5/6 HLA matched (Group 1) and 21 that were 4/6 or 3/6 HLA matched (Group 2). Although patients in Group 2 had a higher incidence of grade II-IV acute graft-versus-host disease (57·9% vs. 5·9%, P = 0·001), they had similar rates of graft failure (5·3% vs. 5·9%, P = 0·742) and overall survival (80·8% vs. 93·8%, P = 0·234) as Group 1. Unmanipulated haplo-HSCT is an effective treatment for SAA children with satisfactory outcome of this cohort, especially in the 5/6 HLA-matched group. For patients in critical situations, such as unresponsive to immunosuppressive therapy, refractory infection and failing first HSCT, to bring forward the timing of haplo-HSCT is a feasible salvage strategy with better and faster donor accessibility.

Risk Factors for Subtherapeutic Tacrolimus Levels after Conversion from Continuous Intravenous Infusion to Oral in Children after Allogeneic Hematopoietic Cell Transplantation

Tacrolimus (FK506) is a calcineurin inhibitor and is an essential component of many immunosuppressive regimens. The oral bioavailability of tacrolimus may be affected by many factors, including patient age and gender, as well as by drug-drug interactions or genetic polymorphisms in drug metabolism. The dosing recommendations for pediatric allogeneic hematopoietic cell transplantation (alloHCT) recipients have been derived from tacrolimus use in adult solid-organ transplantation patients. Data describing the impact of conversion of i.v. tacrolimus to oral on the incidence of acute graft-versus-host disease (aGVHD) are limited in children after alloHCT. In this study, we describe the incidence of grades II to IV aGVHD after conversion from i.v. tacrolimus to oral tacrolimus and study the clinical factors associated with delayed achievement of therapeutic blood levels. In this retrospective analysis, 68 pediatric patients (median age, 6.7 years; range, .25 to 22 years), underwent alloHCT for malignant and nonmalignant diseases and received tacrolimus and mycophenolate mofetil for aGVHD prophylaxis. Among all patients, the median number of days to achieve therapeutic tacrolimus trough concentration (10 ng/mL to 20 ng/mL) was 7 days (range, 0 to 37 days). Twenty-two patients developed grades II to IV aGVHD and the cumulative incidence of grades II to IV aGVHD in all patients was 32.4% (standard error, .06). On multivariate analysis ethnicity (white versus others: odds ratio [OR], -4.5; 95% confidence interval [95% CI], 1.091 to 18.91; P = .038) and ≥ 10 days of subtherapeutic tacrolimus levels in first 30 days on i.v. (OR, -3.8; 95% CI, 1.276 to 11.43; P = .017) were significantly associated with delay in achieving therapeutic tacrolimus trough concentration. The impact of race/ethnicity on therapeutic tacrolimus trough concentration in pediatric alloHCT recipients should be further studied prospectively so that individualized dosing plans can be developed.

Extracorporeal photopheresis versus standard treatment for acute graft-versus-host disease after haematopoietic stem cell transplantation in paediatric patients

BACKGROUND

Acute graft-versus-host disease (aGvHD) is a major cause of morbidity and mortality after haematopoietic stem cell transplantation (HSCT) occurring in 8% to 59% of the recipients. Currently, the therapeutic mainstay for aGvHD is corticosteroids. However, there is no established standard treatment for steroid-refractory aGvHD. Extracorporeal photopheresis (ECP) is a type of immunomodulatory method amongst different therapeutic options that involves ex vivo collection of peripheral mononuclear cells, exposure to the photoactive agent 8-methoxypsoralen and ultraviolet-A radiation, and re-infusion of these treated blood cells to the patient. The mechanisms of action of ECP are not completely understood. This is an updated version of a Cochrane review first published in 2014.

OBJECTIVES

To evaluate the effectiveness and safety of ECP for the management of aGvHD in children and adolescents after HSCT.

SEARCH METHODS

We searched the Cochrane Register of Controlled Trials (CENTRAL) (Issue 9, 2015), MEDLINE (PubMed) and EMBASE (Ovid) databases from their inception to 23 September 2015. We searched the reference lists of potentially relevant studies without any language restrictions. We searched eight trial registers and four conference proceedings on 29 September 2015.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing ECP with or without standard treatment versus standard treatment alone in paediatric patients with aGvHD after HSCT.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed the study selection. We resolved disagreement in the selection of trials by consultation with a third review author.

MAIN RESULTS

We identified no additional studies in the 2015 review update, in total leading to no studies meeting the criteria for inclusion in this review.

AUTHORS' CONCLUSIONS

The efficacy of ECP in the treatment of aGvHD in paediatric patients after HSCT is unknown and its use should be restricted within the context of RCTs. Such studies should address a comparison of ECP alone or in combination with standard treatment versus standard treatment alone. The 2015 review update brought about no additions to these conclusions.

The safety and feasibility of probiotics in children and adolescents undergoing hematopoietic cell transplantation

Hematopoietic cell transplantation (HCT) has become a standard treatment for many adult and pediatric conditions. Emerging evidence suggests that perturbations in the microbiota diversity increase recipients' susceptibilities to gut-mediated conditions such as diarrhea, infection and acute GvHD. Probiotics preserve the microbiota and may minimize the risk of developing a gut-mediated condition; however, their safety has not been evaluated in the setting of HCT. We evaluated the safety and feasibility of the probiotic, Lactobacillus plantarum (LBP), in children and adolescents undergoing allogeneic HCT. Participants received once-daily supplementation with LBP beginning on day -8 or -7 and continued until day +14. Outcomes were compliance with daily administration and incidence of LBP bacteremia. Administration of LBP was feasible with 97% (30/31, 95% confidence interval (CI) 83-100%) of children receiving at least 50% of the probiotic dose (median 97%; range 50-100%). We did not observe any case of LBP bacteremia (0% (0/30) with 95% CI 0-12%). There were not any unexpected adverse events related to LBP. Our study provides preliminary evidence that administration of LBP is safe and feasible in children and adolescents undergoing HCT. Future steps include the conduct of an approved randomized, controlled trial through Children's Oncology Group.

Single-Agent Post-Transplantation Cyclophosphamide as Graft-versus-Host Disease Prophylaxis after Human Leukocyte Antigen-Matched Related Bone Marrow Transplantation for Pediatric and Young Adult Patients with Hematologic Malignancies

High-dose cyclophosphamide given after HLA-matched related and unrelated allogeneic bone marrow transplantation (BMT) for patients with hematologic malignancies is effective single-agent graft-versus-host disease (GVHD) prophylaxis in adults. Data describing outcomes for pediatric and young adult patients have not been reported. Between the years 2007 and 2013, 29 pediatric and young adult patients ages ≤21 years of age treated at our institution for high-risk hematologic malignancies underwent myeloablative HLA-matched related T cell-replete BMT. Eleven patients received post-transplantation cyclophosphamide (PTCy) as single-agent GVHD prophylaxis and were followed prospectively. Eighteen patients received calcineurin inhibitor (CNI)-based standard GVHD prophylaxis and were studied retrospectively as a control group. No acute GVHD (aGVHD) developed in patients receiving PTCy, whereas patients receiving CNI-based GVHD prophylaxis had cumulative incidences of grades II to IV and grades III and IV aGVHD of 27% and 5%, respectively. No patients receiving PTCy developed chronic GHVD, compared to 1 in the control group. Two-year overall survival was similar between the 2 groups (54% PTCy versus 58% CNI-based prophylaxis), as was event-free survival (42% PTCy versus 47% CNI-based). The 5-year cumulative incidence of relapse was 58% for PTCy and 42% for CNI-based GVHD prophylaxis (P = .45). These results suggest that PTCy is a safe and efficacious method of GVHD prophylaxis after an HLA-matched related BMT in the pediatric and young adult population that affords patients to be off all post-transplantation immunosuppression on day +5.

Role of Pharmacogenetics in Hematopoietic Stem Cell Transplantation Outcome in Children

Hematopoietic stem cell transplantation (HSCT) is an established therapeutic procedure for several congenital and acquired disorders, both malignant and nonmalignant. Despite the great improvements in HSCT clinical practices over the last few decades, complications, such as graft vs. host disease (GVHD) and sinusoidal obstructive syndrome (SOS), are still largely unpredictable and remain the major causes of morbidity and mortality. Both donor and patient genetic background might influence the success of bone marrow transplantation and could at least partially explain the inter-individual variability in HSCT outcome. This review summarizes some of the recent studies on candidate gene polymorphisms in HSCT, with particular reference to pediatric cohorts. The interest is especially focused on pharmacogenetic variants affecting myeloablative and immunosuppressive drugs, although genetic traits involved in SOS susceptibility and transplant-related mortality are also reviewed.

Approaches for the prevention of graft-versus-host disease following hematopoietic cell transplantation

Allogeneic hematopoietic cell transplantation (HCT) is an important therapeutic option for malignant and non-malignant diseases, but the more widespread application of the therapy remains limited by the occurrence of graft versus host disease (GVHD). GVHD results from immune-mediated injury by donor immune cells against tissues in the HCT recipient, and can be characterized as acute or chronic depending on the time of onset and site of organ involvement. The majority of efforts have focused on GVHD prevention. Calcineurin inhibitors are the most widely used agents and are included in almost all regimens. Despite current prophylaxis strategies, 40-70% of patients remain at risk for developing GVHD. Herein, we review standard and emerging therapies used in GVHD management.

The potential of cytotherapeutics in hematologic reconstitution and in the treatment and prophylaxis of graft-versus-host disease. Chapter I: current practice and remaining unmet medical needs

Hematopoietic stem cell transplantation is a life-saving treatment for inherited anemias, immunodeficiencies or hematologic malignancies. When using partially HLA-matched allografts, a major complication is graft-versus-host disease (GvHD). The ideal attributes of a transformational new GvHD treatment include improved survival, decreased corticosteroids, decreased antifungals, improved quality of life through decreased infections, reduced number of hospital stay days, reduced risks of developing chronic GvHD impact on lower GI tract and liver, prophylactic benefits and decreased GvHD relapses, but, in the case of cancer, without negatively impacting beneficial graft-versus-tumor effects. The current practice of hematopoietic stem cell transplantation, its incidence and its unmet medical needs are reviewed here and discussed.

Impact of inflammatory cytokine gene polymorphisms on developing acute graft-versus-host disease in children undergoing allogeneic hematopoietic stem cell transplantation

Single nucleotide polymorphisms (SNPs) in gene encoding pro- and anti-inflammatory factors have been associated with the occurrence of aGvHD. We retrospectively tested a wide panel of 38 polymorphisms in 19 immunoregulatory genes, aiming to first establish, in a pediatric HSCT setting, which SNPs were significantly associated with the development of aGvHD. A significant association was found between aGvHD grades II–IV and SNPs of donor IL10-1082GG, and Fas-670CC + CT and recipient IL18-607 TT + TG genotype. aGvHD grades III-IV resulted associated with donor IL10-1082GG, Fas-670CC + CT, and TLR4-3612TT as well as the use of peripheral CD34+ cells as stem cell source. The multivariate analysis confirmed the association between donor IL10-1082GG and Fas-670CC + CT and aGvHD grades II–IV and between donor IL10-1082GG and TLR4-3612TT and aGvHD grades III-IV. In conclusion we found an association between IL10, FAS, and TLR4 in the donor and IL18 in the recipient and an increased risk of developing aGvHD in transplanted children. Knowledge of the SNPs of cytokine genes associated with aGvHD represents a useful tool for an integrated pretransplantation risk assessment and could guide the physicians to an optimal and more accurate HSCT planning.

Hematopoietic cell transplantation and cellular therapeutics in the treatment of childhood malignancies

Hematopoietic cell transplantation (HCT) represents the most common and effective form of immunotherapy for childhood malignancies. The role of the graft-versus-leukemia effect in allogeneic HCT has been well established in childhood malignancies, but is also associated with short-term and long-term morbidity. HCT may be ineffective in some settings at obtaining control of the malignancy, and as such, cannot be used as a universal cancer immunotherapy. Novel therapies using dendritic cell vaccinations, tumor-infiltrating lymphocytes, and chimeric antigen receptor T cells are being evaluated as potential adjuvants to HCT.

Establishing Feasibility of Early Palliative Care Consultation in Pediatric Hematopoietic Stem Cell Transplantation

Children and adolescents undergoing hematopoietic stem cell transplantation (HSCT) encounter a number of distressing physical symptoms and existential distress but may not be afforded timely access to palliative care services to help ameliorate the distress. This feasibility study investigated the acceptability and outcomes of early palliative care consultation to promote comfort in this population. A longitudinal, descriptive cohort design examined both provider willingness to refer and willingness of families to receive palliative care interventions as well as satisfaction. Feasibility was demonstrated by 100% referral of eligible patients and 100% of patient and family recruitment (N = 12). Each family received 1 to 3 visits per week (ranging from 15 to 120 minutes) from the palliative care team. Interventions included supportive care counseling and integrative therapies. Families and providers reported high satisfaction with the nurse-led palliative care consultation. Outcomes included improvement or no significant change in comfort across the trajectory of HSCT, from the child and parental perspective. Early integration of palliative care in HSCT is feasible and acceptable to families and clinicians.

Recent advances in the management of graft-versus-host disease

Graft-versus-host disease (GvHD) remains a significant hurdle in overcoming the morbidity and mortality associated with haemopoietic stem cell transplantation in children. Better understanding of its pathobiology is facilitating the development of biomarkers for the severity of acute GvHD and treatment response, and has led to the introduction of a more prognostically relevant grading system for chronic GvHD. These enable stratification of appropriate prophylactic and treatment strategies according to the risk profiles of individual patients. Steroid-refractory acute GvHD has a poor prognosis, but early reports of the use of new immunosuppressive drugs and especially cellular treatments with extracorporeal photopheresis and mesenchymal stem cells suggest improved short-term outcomes and offer the promise of increased longer-term survival rates.

Risk for complications in patients with hemophagocytic lymphohistiocytosis who undergo hematopoietic stem cell transplantation: myeloablative versus reduced-intensity conditioning regimens

Allogeneic hematopoietic stem cell transplantation (HSCT) is the only curative option for patients with primary hemophagocytic lymphohistiocytosis (HLH) and for patients with secondary HLH who fail to respond to therapy. Advances in HSCT and supportive care measures have resulted in improved patient outcomes and decreased treatment-related mortality. Despite the overall improvement in outcome, HLH patients who undergo HSCT using myeloablative conditioning regimens are still at significant risk for complications. The HLH-94 study conducted by the Histiocyte Society reported a 30% TRM with increased pulmonary and hepatic complications. Recently, the use of reduced-intensity conditioning (RIC) regimens has shown favorable outcomes when compared to conventional HSCT and lower rate of acute complications. In this review we compare the potential complications of myeloablative and RIC regimens for HSCT in HLH patients.

Extracorporeal photopheresis versus standard treatment for acute graft-versus-host disease after haematopoietic stem cell transplantation in paediatric patients

BACKGROUND

Acute graft-versus host disease (aGvHD) is a major cause of morbidity and mortality after haematopoietic stem cell transplantation (HSCT) occurring in 8% to 59% of the recipients. Currently, the therapeutic mainstay for aGvHD is corticosteroids. However, there is no established standard treatment for steroid-refractory aGvHD. Extracorporeal photopheresis (ECP) is a type of immunomodulatory method amongst different therapeutic options that involves ex vivo collection of peripheral mononuclear cells, exposure to the photoactive agent 8-methoxypsoralen and ultraviolet-A radiation, and re-infusion of these treated blood cells to the patient. The mechanisms of action of ECP are not completely understood

OBJECTIVES

To evaluate the effectiveness and safety of ECP for the management of aGvHD in children and adolescents after HSCT.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (Issue 9, 2012), MEDLINE/PubMed and EMBASE (Ovid) databases from their inception to 12 September 2012. We searched the reference lists of potentially relevant studies without any language restriction. We searched eight trial registers and four conference proceedings. We also contacted an expert in the field to request information on unpublished study that involves ECP in aGvHD after HSCT.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing ECP with or without standard treatment versus standard treatment alone in paediatric patients with aGvHD after HSCT.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed the study selection. We resolved disagreement in the selection of trials by consultation with a third review author.

MAIN RESULTS

We found no studies meeting the criteria for inclusion in this review.

AUTHORS' CONCLUSIONS

The efficacy of ECP in the treatment of aGvHD in paediatric patients after HSCT is unknown and its use should be restricted within the context of RCTs. Such studies should address a comparison of ECP alone or in combination with standard treatment versus standard treatment alone. 

Risk factors for short term thyroid dysfunction after hematopoietic stem cell transplantation in children

Purpose

The purpose of this study was to evaluate short-term thyroid dysfunction and related risk factors in pediatric patients who underwent hematopoietic stem cell transplantation (HSCT) during childhood.

Methods

We studied 166 patients (100 boys and 66 girls) who underwent HSCT at the Catholic HSCT Center from January 2004 through December 2009. The mean age at HSCT was 10.0±4.8 years. Thyroid function of the patients was tested before and during 3 months of HSCT.

Results

Out of 166 patients, 165 (99.4%) underwent allotransplantation. Acute graft-versus-host disease (GVHD, grades II to IV) developed in 76 patients. Conditioning regimens before HSCT include total body irradiation (n=57), busulfan (n=80), and reduced intensity (n=29). Forty-five (27.1%) had thyroid dysfunction during 3 months after HSCT (29 euthyroid sick syndrome [ESS], 6 subclinical hyperthyroidism, 4 subclinical hypothyroidism, 3 hypothyroxinemia, 2 overt hyperthyroidism, and 1 high T₄ syndrome). In a univariate logistic regression analysis, age at HSCT (P=0.002) and acute GVHD (P=0.009) had statistically significant relationships with thyroid dysfunction during 3 months after HSCT. Also, in a univariate logistic regression analysis, ESS (P=0.014) showed a strong statistically significant association with mortality.

Conclusion

In our study 27.1% patients experienced thyroid dysfunction during 3 months after HSCT. Increase in age and acute GVHD may be risk factors for thyroid dysfunction during 3 months after HSCT. There was a significant association between ESS and mortality.

Advances in critical care of the pediatric hematopoietic stem cell transplant patient

Hematopoietic stem cell transplant (SCT) remains a curative option for a variety of malignant and non-malignant disorders in children. Following transplant a proportion of SCT recipients become critically ill and need intensive care. Critical illness may occur in the setting of transplant complications such as graft versus host disease (GVHD), idiopathic pneumonia syndrome (IPS), veno-occlusive disease (VOD) and transplant associated thrombotic microangiopathy (TA-TMA). Hence, familiarity with recent advances in the transplant process and complications is crucial for the intensivist. This article will highlight common complications encountered in the critically ill SCT recipient.

Mesenchymal stem cells as cellular immunotherapeutics in allogeneic hematopoietic stem cell transplantation

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a curative treatment option in hematopoietic disorders, immunodeficiencies and leukemia. To date graft-versus-host disease (GvHD) represents a life-threatening complication even if associated with beneficial antileukemic reactivity. GvHD is the clinical manifestation of donor cells reacting against host tissue. Because of their ability to facilitate endogenous repair and to attenuate inflammation, MSC have evolved as a highly attractive cellular therapeutic in allo-HSCT. Here we report on the clinical experience in the use of MSC to enhance engraftment and prevent and treat acute and chronic GvHD. In early clinical trials, MSC have shown considerable benefit in the setting of manifest GvHD. These encouraging results warrant further exploration.

Prediction of area under the cyclosporine concentration versus time curve in children undergoing hematopoietic stem cell transplantation

This prospective study aimed to validate a previously developed first-dose limited sampling strategy (LSS) to predict the area under the cyclosporine concentration-versus-time curve (AUC) and to develop and then validate an LSS to predict cyclosporine AUC at steady state. This two-center Canadian study included children (ages .4 to 17.2 years) undergoing myeloablative allogeneic hematopoietic stem cell transplantation receiving cyclosporine for acute graft-versus-host disease prophylaxis. There were three cohorts, each incorporating 24 AUC determinations: first-dose LSS validation, steady-state LSS development, and steady-state LSS validation. Patients contributing data to either of the development cohorts were excluded from the corresponding validation group. Cyclosporine was given every 12 hours as a 2-hour infusion. Cyclosporine AUC was determined after administration of the first cyclosporine dose (8 samples) and then once weekly (9 samples) until engraftment. Steady-state LSSs were developed using stepwise multiple linear regression. An LSS was considered to provide an acceptable estimate of AUC if the lower limit of the 95% confidence limit (CL) of the intraclass coefficient was .8 or higher and both bias and precision were 15% or less. Fifty-three children age .4 to 18 years participated. Cyclosporine concentrations drawn up to 4 hours from the start of the infusion correlated most strongly with AUC. The previously developed first-dose LSSs and three steady-state LSSs met criteria for acceptability. The intraclass coefficients of the three-point first-dose LSS validation cohort, three-point steady-state LSS development cohort, and three-point steady-state LSS validation cohort were .974 (95% CL: .941 to .988), .984 (95% CL: .965 to .993), and .993 (95% CL: .984 to .997), respectively. The three-point first-dose (2, 6, and 8 hours) and steady-state (2, 2.5, and 8 hours) LSSs are valid measures of cyclosporine AUC after intravenous administration over 2 hours. Their use in a prospective evaluation of the relationship between cyclosporine AUC and hematopoietic stem cell transplantation clinical outcomes in children is suggested.

Long-term follow-up of children treated with daclizumab for steroid-refractory gastrointestinal GvHD in a prospective study

Daclizumab, a humanized MoAB to IL-2Ra, has been found to be safe and effective in adults with refractory GvHD; however, data in children are limited. The aim of this prospective study was to evaluate the long-term safety and efficacy of daclizumab in children with steroid-refractory GI aGvHD. This study included 13 children who developed steroid-refractory GI GvHD between 2007 and 2009. When first-line treatment failed, daclizumab was given in a regimen of 1 mg/kg intravenously and then repeated on a 10- to 14-day interval for maximum five doses if necessary. Daclizumab was well tolerated, but infections were common. Ten patients responded to daclizumab completely, one patient responded partially, and two patients failed to respond. With a median follow-up of 630 days, 10 patients were alive and free of severe infections, but among them, four patients were suffering from cGvHD. Of the three remaining patients, one died because of bacterial meningitis, and the other two patients died because of severe refractory GI GvHD. This long-term evaluation showed that daclizumab could be an effective and relatively safe treatment in most of the pediatric patients with severe steroid-refractory GI GvHD.

Pretransplant conditioning with Campath-1H (alemtuzumab) in pediatric matched unrelated hematopoietic stem cell transplants: an institutional experience

Graft versus host disease (GVHD) remains a major cause of mortality and morbidity after matched unrelated hematopoietic stem cell transplantation (HSCT). Campath-1 H (alemtuzumab), a humanized monoclonal antibody to CD52 antigen, is thought to reduce GVHD incidence through in vivo T-cell depletion. Through the same mechanism it can potentially increase the risk of relapse by reducing the graft versus leukemia effect and possibly increase the risk of infection due to delayed immune recovery. A retrospective case analysis of 17 pediatric matched unrelated HSCTs done in our institution between January 2003 and June 2009 with Campath-1H as part of the pretransplant conditioning regimen was conducted. Grade I-II acute GVHD was noted in 29.4% of the HSCTs. No patient developed chronic GVHD. All but one patient with severe aplastic anemia engrafted. A relapse of primary disease was noted in 35.3% of the transplants. Three patient deaths were due to relapse and 1 due to disseminated varicella infection. Overall survival was 100% and 94% at 100 days and 1 year, respectively. Our experience suggests Campath-1H used as part of pretransplant conditioning regimen in pediatric unrelated HSCTs effectively reduces the risk of serious GVHD with no apparent increase in life-threatening infections or relapse compared with that reported with conventional regimens. Larger studies, with longer duration of follow-up, are required to further assess its role with regards to graft versus leukemia effect and to establish if the decreased incidence of GVHD and infectious complications is sustained in larger cohorts.

Osteonecrosis in children after allogeneic hematopoietic cell transplantation: study of prevalence, risk factors and longitudinal changes using MR imaging

Osteonecrosis after hematopoietic SCT (HCT) has seldom been addressed in pediatric populations. At our institution, since January 2002, children undergoing allogeneic HCT (alloHCT) receive yearly follow-up magnetic resonance imaging (MR) of hips and knees. To estimate the prevalence, longitudinal changes and associated risk factors for osteonecrosis after alloHCT, we reviewed MRs for children who underwent single alloHCT during the study period. We analyzed 149 of 344 patients who had post-HCT MR imaging performed (84 males; median age 11 years (range, 0.5-21 years)), median follow-up time was 32.6 months (range, 2.8-97.2 months). In all, 44 (29.5%) developed osteonecrosis of hips and/or knees; of those, 20 (45%) had at least 30% epiphyseal involvement. In 23 (52%), osteonecrosis lesions were identified in the first and in 43 (98%) by the third yearly scan. Knees were more frequently involved than hips; severity of osteonecrosis was greater in hips. Those who had pre-alloHCT osteonecrosis, two patients' hips and six patients' knees resolved completely; three patients' osteonecrosis lesions regressed after alloHCT. On risk factor analysis, age at time of alloHCT (P=0.051) and osteonecrosis identified by MRs before alloHCT (P=0.001) were the primary risk factors. This analysis shows that preventive strategies for osteonecrosis in this population should focus on measures to minimize risk factors before alloHCT.

Osteonecrosis in children after allogeneic hematopoietic cell transplantation: study of prevalence, risk factors and longitudinal changes using MR imaging

Osteonecrosis after hematopoietic stem cell transplantation (HCT) has seldom been addressed in pediatric populations. At our institution, since January 2002, children undergoing allogeneic HCT (alloHCT) receive yearly follow-up magnetic resonance imaging (MR) of hips and knees. To estimate the prevalence, longitudinal changes and associated risk factors for osteonecrosis after alloHCT, we reviewed MRs for children who underwent single alloHCT during the study period. We analyzed 149 of 344 patients who had post HCT MRI imaging performed [84 males; median age11 years (range, 0.5–21years)], median follow-up time was 32.6 months (range, 2.8–97.2 months). Forty-four (29.5%) developed osteonecrosis of hips and/or knees; of those, 20 (45%) had at least 30% epiphyseal involvement. In 23 (52%) osteonecrosis lesions were identified in the first, and 43 (98%) by the third yearly scan. Knees were more frequently involved than hips; severity of osteonecrosis was greater in hips. Those who had pre-alloHCT osteonecrosis, two patients’ hips and six patients’ knees resolved completely; three patients’ osteonecrosis lesions regressed after alloHCT. On risk factor analysis, age at time of alloHCT (p=0.051) and osteonecrosis identified by MRs before alloHCT (p=0.001) were the primary risk factors. This analysis shows that preventive strategies for osteonecrosis in this population should focus on measures to minimize risk factors before alloHCT.

Update on the mechanism of action and on clinical efficacy of extracorporeal photopheresis in the treatment of acute and chronic graft versus host disease in children

Extracorporeal photopheresis (ECP) has been used for treatment of steroid-refractory graft versus host disease (GVHD) with encouraging results. Although its exact mechanism of action is not fully understood, photoapheresed cells seem to induce a selective immune response directed against alloreactive T cell populations without causing generalized immunosuppression. Current pediatric experience with ECP for GVHD is available in the form of a few retrospective small studies concerning children with steroid refractory GVHD. Reviewing these data we conclude that ECP is a safe procedure, well tolerated even in low-weight pediatric patients, which warrants further evaluation in well-designed, prospective, controlled studies.

Mesenchymal stromal cells for treatment of steroid-refractory GvHD: a review of the literature and two pediatric cases

Severe acute graft versus host disease (GvHD) is a life-threatening complication after allogeneic hematopoietic stem cell transplantation. Human mesenchymal stromal cells (MSCs) play an important role in endogenous tissue repair and possess strong immune-modulatory properties making them a promising tool for the treatment of steroid-refractory GvHD. To date, a few reports exist on the use of MSCs in treatment of GvHD in children indicating that children tend to respond better than adults, albeit with heterogeneous results.

We here present a review of the literature and the clinical course of two instructive pediatric patients with acute steroid-refractory GvHD after haploidentical stem cell transplantation, which exemplify the beneficial effects of third-party transplanted MSCs in treatment of acute steroid-refractory GvHD. Moreover, we provide a meta-analysis of clinical studies addressing the outcome of patients with steroid-refractory GvHD and treatment with MSCs in adults and in children (n = 183; 122 adults, 61 children). Our meta-analysis demonstrates that the overall response-rate is high (73.8%) and confirms, for the first time, that children indeed respond better to treatment of GvHD with MSCs than adults (complete response 57.4% vs. 45.1%, respectively).

These data emphasize the significance of this therapeutic approach especially in children and indicate that future prospective studies are needed to assess the reasons for the observed differential response-rates in pediatric and adult patients.

Higher CD34(+) and CD3(+) cell doses in the graft promote long-term survival, and have no impact on the incidence of severe acute or chronic graft-versus-host disease after in vivo T cell-depleted unrelated donor hematopoietic stem cell transplantation in children

The aim of our study was to compare the results of unrelated donor (UD) peripheral blood stem cell transplantation versus UD bone marrow transplantation and to analyze the impact of infused CD34(+) and CD3(+) cell doses on survival and incidence of severe graft-versus-host disease (GVHD) in 187 children who underwent UD hematopoietic cell transplantation with the use of in vivo T cell depletion (antithymocyte globulin or CAMPATH-1H). HLA typing was performed at the "high-resolution" level. Patients receiving > or =10 x 10(6) CD34(+) cells/kg and > or =4 x 10(8) CD3(+) cells/kg had better overall and disease-free survival. Multivariate analysis has shown that both infused CD34(+) cell dose <10 x 10(6)/kg and CD3(+) cell dose <4 x 10(8)/kg were independent risk factors for mortality (relative risk [RR] 1.8 and 1.71, P = .009 and .016, respectively). Regarding disease-free survival, multivariate analysis has revealed another independent risk factor for poor outcome apart from the 2 earlier-mentioned cell doses, which was the use of donors mismatched at 2 HLA antigens or 3 HLA allele/antigens (RR 2.5, P = .004). In age groups 0-10 years and 10-20 years, CD34(+) cell doses higher than the age-adjusted median dose clearly favored survival. Higher infused doses of CD34(+) and CD3(+) cells did not result in an increased rate of severe GVHD. The use of mismatched donors was the only independent risk factor for the incidence of severe acute GVHD (RR 2.2, P = .046). The report demonstrates for the first time in a pediatric cohort, that higher doses of transplanted CD34(+) and CD3(+) cells lead to an improved survival without an increased risk of severe GVHD. The study findings may be limited to the population of patients receiving in vivo T cell depletion, which is now broadly used in unrelated donor setting in Europe.

NanoLC-MS/MS analyses of urinary desmosine, hydroxylysylpyridinoline and lysylpyridinoline as biomarkers for chronic graft-versus-host disease

Chronic graft-versus-host disease (cGVHD) is a common and potentially lethal complication of allogeneic hematopoietic stem cell transplantation (HSCT). cGVHD as well as the transplant procedure itself (chemotherapy with or without radiotherapy) can lead to the degradation of connective tissue components such as elastin and collagen. The catabolism of these structural proteins releases desmosine (DES), lysylpyridinoline (LP), hydroxylysylpyridonoline (HP), and related pyridinium-based cross-linkers analogues that could represent potential biomarkers for cGVHD. This study reports the development of a sensitive liquid chromatography/tandem mass spectrometry method for the simultaneous analysis of N-propyl derivatives of DES, HP, and LP. The concentrations of free and total forms of urinary DES, HP, and LP were determined using synthetic deuterated internal standards. This method enabled accurate quantitation of these pyridinium-based cross-linkers from as little as 100 microL of urine with detection limits of 0.03-0.10 ng/mL. These compounds were analyzed in urine samples from three groups of patients: (1) Healthy volunteers, (2) Autologous HSCT recipients (who cannot develop cGVHD), and (3) Allogeneic HSCT recipients at onset of cGHVD. These analyses revealed that the urinary concentrations of DES, HP, and LP in the autologous recipients were greater or equal to the cGVHD group although both groups showed marked increase in the levels of these compounds compared to healthy individuals. These results suggest that the chemotherapy treatment has significant effects on the turnover of elastin and collagen, and that these biomarkers could be effective during prospective analyses to determine the onset of cGVHD.

Advancement of pediatric blood and marrow transplantation research in North America: priorities of the Pediatric Blood and Marrow Transplant Consortium

Advances in pediatric bone marrow transplantation (BMT) are slowed by the small number of patients with a given disease who undergo transplantation, a lack of sufficient infrastructure to run early-phase oncology protocols and studies of rare nonmalignant disorders, and challenges associated with funding multi-institutional trials. Leadership of the Pediatric Blood and Marrow Transplant Consortium (PBMTC), a large pediatric BMT clinical trials network representing 77 active and 45 affiliated centers worldwide, met in April 2009 to develop strategic plans to address these issues. Key barriers, including infrastructure development and funding, along with scientific initiatives in malignant and nonmalignant disorders, cellular therapeutics, graft-versus-host disease, and supportive care were discussed. The PBMTC's agenda for approaching these issues will result in infrastructure and trials specific to pediatrics that will run through the PBMTC or its partners, the Blood and Marrow Transplant Clinical Trials Network and the Children's Oncology Group.

Regenerative stromal cell therapy in allogeneic hematopoietic stem cell transplantation: current impact and future directions

Regenerative stromal cell therapy (RSCT) has the potential to become a novel therapy for preventing and treating acute graft-versus-host disease (GVHD) in the allogeneic hematopoietic stem cell transplant (HSCT) recipient. However, enthusiasm for using RSCT in allogeneic HSCT has been tempered by limited clinical data and poorly defined in vivo mechanisms of action. As a result, the full clinical potential of RSCT in supporting hematopoietic reconstitution and as treatment for GVHD remains to be determined. This manuscript reviews the immunomodulatory activity of regenerative stromal cells in preclinical models of allogeneic HSCT, and emphasizes an emerging literature suggesting that microenvironment influences RSC activation and function. Understanding this key finding may ultimately define the proper niche for RSCT in allogeneic HSCT. In particular, mechanistic studies are needed to delineate the in vivo effects of RSCT in response to inflammation and injury associated with allogeneic HSCT, and to define the relevant sites of RSC interaction with immune cells in the transplant recipient. Furthermore, development of in vivo imaging technology to correlate biodistribution patterns, desired RSC effect, and clinical outcome will be crucial to establishing dose-response effects and minimal biologic dose thresholds needed to advance translational treatment strategies for complications like GVHD.

Cost-effectiveness of private umbilical cord blood banking

OBJECTIVE

To investigate the cost-effectiveness of private umbilical cord blood banking.

METHODS

A decision-analytic model was designed comparing private umbilical cord blood banking with no umbilical cord blood banking. Baseline assumptions included a cost of $3,620 for umbilical cord blood banking and storage for 20 years, a 0.04% chance of requiring an autologous stem cell transplant, a 0.07% chance of a sibling requiring an allogenic stem cell transplant, and a 50% reduction in risk of graft-versus-host disease if a sibling uses banked umbilical cord blood.

RESULTS

Private cord blood banking is not cost-effective because it cost an additional $1,374,246 per life-year gained. In sensitivity analysis, if the cost of umbilical cord blood banking is less than $262 or the likelihood of a child needing a stem cell transplant is greater than 1 in 110, private umbilical cord blood banking becomes cost-effective.

CONCLUSION

Currently, private umbilical cord blood banking is cost-effective only for children with a very high likelihood of needing a stem cell transplant. Patients considering private blood banking should be informed of the remote likelihood that a unit will be used for a child or another family member.

LEVEL OF EVIDENCE

III.

An age-dependent pharmacokinetic study of intravenous and oral mycophenolate mofetil in combination with tacrolimus for GVHD prophylaxis in pediatric allogeneic stem cell transplantation recipients

Acute graft-versus-host disease (aGVHD) still remains a major limiting factor following allogeneic stem cell transplantation (AlloSCT) in pediatric recipients. Mycophenolate mofetil (MMF), an uncompetitive selective inhibitor of inosine monophosphate dehydrogenase, is a new immunosuppressant agent without major mucosal, hepatic, or renal toxicity compared to other prophylactic aGVHD immunosuppressant drugs. Although there has been an extensive pharmacokinetic (PK) experience with MMF administration following solid organ transplantation in children, there is a paucity of PK data following its use in pediatric AlloSCT recipients. We investigated the safety and PK of MMF as GVHD prophylaxis following intravenous (i.v.) and oral (p.o.) administration (900 mg/m(2) every 6 hours) in conjunction with tacrolimus, after myeloablative (MA) and nonmyeloablative (NMA) conditioning and AlloSCT in 3 distinct age groups of pediatric AlloSCT recipients (0-6 years, 6-12 years, and 12-16 years). Mycophenolic acid (MPA) in plasma samples was measured either by high-performance liquid chromatography (HPLC) or liquid chromatography/mass spectrometry (LC/MS/MS) as we have previously described. Plasma samples were obtained at baseline and at 0.5, 1, 2, 3, 4, and 6 hours after i.v. dosing on days +1, +7, +14, and at 2 time points between day +45 and +100 after p.o. administration post AlloSCT. MPA PK analysis included AUC (0-6 hours), C(max), T(max), C(ss), V(ss), C trough (C(0)), CL, and T((1/2).) Thirty-eight patients, with a median age of 8 years (0.33-16 years), 20/18 M:F ratio, 21/17 malignant/nonmalignant disease, 17/21 MA: NMA conditioning, 16 of 22 related/unrelated allografts. Median time to myeloid and platelet engraftment was 18 and 31 days, respectively. Mean donor chimerism on day +60 and +100 was 83% and 90%, respectively. Probability of developing aGVHD grade II-IV and extensive chronic GVHD (cGVHD) was 54% and 34%, respectively. There was significant intra- and interpatient MMF PK variability. There was a significant increase in i.v. MPA area under the curve (AUC)(0-6 hour) and C(max) (P < .0003) and a significant decrease in CL(ss) (P < .002) and V(ss) (P < .001) on day +14 versus day +7. Children <12 years of age had a significant increase in i.v. MPA T(max) (P = .01), V(ss) (P = .028), and CL(ss) (P < .001) compared to the older age group. There was a trend in increased i.v. MPA CL(ss) following MA versus NMA conditioning (P < .054); i.v. and p.o. MMF administration (900 mg/m(2) every 6 hours) in combination with tacrolimus was well tolerated in pediatric AlloSCT recipients. There was a significant increase in MPA exposure on day +14 versus day +7, suggesting improved enterohepatic recirculation at day +14 post-AlloSCT. Children <12 years of age appear to have a significantly different MPA PK profile compared to older children and adolescents and may require more frequent dosing.

Bone marrow transplantation: new approaches to immunosuppression and management of acute graft-versus-host disease

PURPOSE OF REVIEW

Acute graft-versus-host disease (GVHD) significantly limits the application and the success of allogeneic hematopoietic stem cell transplantation (HSCT). Novel therapies that target the aberrant immune response underlying GVHD are reviewed with particular emphasis on immunomodulatory agents currently incorporated into clinical trials. In addition, regenerative stromal cellular therapy (RSCT) is discussed as an emerging form of novel GVHD therapy.

RECENT FINDINGS

Knowledge for transplant immunology, particularly as it relates to underlying pathophysiology of GVHD, has dramatically increased over the last decade. As a result, new immunomodulatory therapies have been used to treat steroid-refractory GVHD. However, their success has been limited by their lack of clinical experience during HSCT as well as by their associated toxicity profiles. RSCT uniquely offers the potential to enhance donor-derived hematopoiesis and immunity and to ameliorate adverse sequelae associated with GVHD.

SUMMARY

An exciting era incorporating the use of cellular therapeutics during HSCT has arrived. As the experience and understanding for cellular therapies, in general, and RSCT, in particular, increases, so too will their success in benefiting the HSCT recipient beyond limitations of current pharmaceutical agents.

Acute graft-versus-host disease: differing risk with differing graft sources and conditioning intensity

Acute graft-versus-host disease (aGVHD) is a constant component of allogeneic hematopoietic cell transplantation (HCT), with variations in incidence and severity affected by the graft source, human leukocyte antigen (HLA) compatibility, and the preparative regimen. The graft source - related versus unrelated donors, bone marrow (BM) versus peripheral blood (PB), umbilical cord blood (UCB) versus unrelated donor BM - are discussed in this review, as well as myeloablative versus reduced-intensity (RI) preparative regimens. Recent comparisons of matched related versus matched unrelated donor HCT support a minimal difference in aGVHD between these two donor sources. The use of BM versus mobilized PB in the matched related donor (MRD) setting has been compared in randomized as well as phase-II comparative clinical trials which support a slight increase in aGVHD in the adult population. Similar results have been seen in the unrelated donor (URD) setting, although based on minimal comparative data to date. Preliminary comparisons of UCB versus URD BM have shown a decreased incidence of aGVHD with UCB, despite increased HLA mismatching. Haploidentical HCT has continued to be explored, with limitations due to delayed immune reconstitution and disease relapse. Many reduced-intensity preparative regimens have been published, with a reduced or minimal difference in incidence of aGVHD when historically compared to myleoablative preparative regimens. More formal comparisons of the different graft sources as well as preparative regimen intensities will be required to determine a more accurate picture of the differences between these transplantation alternatives.