Posttransplant Cyclophosphamide for HLA-haploidentical Transplantation in Patients With Mucopolysaccharidosis.

We successfully used a haploidentical transplantation protocol with posttransplant cyclophosphamide (CY) (50 mg/kg/d on days +3 and +4) for in vivo T-cell depletion in patients with mucopolysaccharidosis using reduced-intensive conditioning regimens, followed by a busulfan-based conditioning regimen, which included busulfan (12 to 16 mg/kg) and fludarabine(150 to 200 mg/m)+rabbit antihuman thymocyte globulin (7.5 to 10 mg/kg) as a conditioning regimen. Cyclosporine or tacrolimus, methotrexate, mycophenolate mofetil, and methylprednisolone were administered to prevent graft-versus-host disease (GVHD). After follow-up for a median period of 1.5 years, all 8 patients without preexisting severe comorbidities and early transplant referrals are alive, with 100% donor chimerism and excellent performance status. Only 1 patient developed chronic GVHD(II). We conclude that posttransplant CY is effective in vivo for T-cell depletion to promote full donor engraftment in patients with mucopolysaccharidosis. In addition, with posttransplant CY, the procedure reduced the rate of GVHD and the cost of transplant and improved the patients' quality of life.

Allogeneic Hematopoietic Stem Cell Transplantation in Thirty-Four Pediatric Cases of Mucopolysaccharidosis-A Ten-Year Report from the China Children Transplant Group.

We investigated the efficacy of allogeneic hematopoietic stem cell transplantation (alloHSCT) in pediatric patients with mucopolysaccharidosis (MPS). A retrospective analysis of transplantation data from 34 cases of MPS from the China Children Transplant Group, treated between December 2004 and September 2015, was conducted. Among the 34 cases, 12 cases were type I, 12 were type II, 4 were type IV, 4 were type VI, and 2 were of an unknown type. The median age at transplantation was 3.75 years (range, 1 to 7 years); the median follow-up time was 14 months (range, 2 to 119 months). Eleven patients underwent unrelated cord blood transplantation and 23 underwent peripheral blood stem cell transplantation (4 cases with an HLA-matched sibling donor, 2 cases with an HLA-mismatched related donor, and 17 cases with an unrelated donor). A busulfan-based myeloablative regimen was used as a conditioning regimen. The estimated overall survival at 3 years was 84.8% ± 6.3% and 91.2% of the patients (31 of 34) achieved full donor chimerism. Twenty-seven children were evaluable and all but 1 (carrier sibling donor; enzyme level improved but failed to reach normal) achieved normal enzyme level after transplantation. The incidence of grades II to IV acute graft-versus-host disease (aGVHD) was 41.1% (14 of 34), wherein the incidence of grades III and IV aGVHD was 11.8% (4 of 34). The incidence of moderate-to-severe chronic graft-versus-host disease was 5.9% (2 of 34). There was a significant difference in the survival rate between children who received transplantation before 2009 and those after 2009 (55.6% versus 95.7%, P = .002); the survival rate was lower in patients with pneumonia before transplantation than in those with no active infection before transplantation (66.7% versus 95.5%, P = .019), and no significant differences in survival rates were observed among children with different disease types, ages at transplantation, donor/graft source, and conditioning regimens. After transplantation, upper-airway obstruction, hepatosplenomegaly, and corneal clouding were significantly improved; hearing and motor function were improved to a certain extent; valvular heart disease was improved in some patients but progressed in others; and short stature and speech skills showed little improvement. AlloHSCT may save the lives of patients with MPS I, II, IV or VI and could improve quality of life. Pretransplantation pneumonia affects transplantation outcomes. Advances in transplantation protocols and techniques help to improve patient prognosis. Well-matched unrelated donors can also be an ideal donor source. Standardized follow-up and a multidisciplinary team contribute to accurate evaluation of long-term post-transplantation outcome and further improve the quality of life of MPS patients.

Hematopoietic cell transplantation for mucopolysaccharidosis patients is safe and effective: results after implementation of international guidelines.

Allogeneic hematopoietic cell transplantation (HCT) is the only treatment able to prevent progressive neurodegenerative disease in a selected group of mucopolysaccharidosis (MPS) disorders. However, its use was historically limited by the high risk of graft failure and transplantation-related morbidity and mortality. Therefore, since 2005 new international HCT guidelines for MPS disorders were proposed. The survival and graft outcomes of MPS patients receiving HCT according to these guidelines in 2 European centers of expertise were evaluated. Two consecutive conditioning regimens were used, busulfan/cyclophosphamide or fludarabine/busulfan-based, both with exposure-targeted i.v. busulfan. A noncarrier matched sibling donor (MSD), matched unrelated cord blood (UCB), or matched unrelated donor (MUD) were considered to be preferred donors. If not available, a mismatched UCB donor was used. Participants were 62 MPS patients (56 MPS type I-Hurler, 2 MPS type II, 2 MPS type III, and 2 MPS type VI) receiving HCT at median age 13.5 months (range, 3 to 44). Forty-one patients received a UCB donor, 17 MSD, and 4 MUD. High overall survival (95.2%) and event-free survival (90.3%) were achieved with only low toxicity: 13.3% acute graft-versus-host disease aGVHD) grades II to IV and 14.8% chronic GVHD (1.9% extensive). A mismatched donor predicted for lower event-free survival (P = .04). A higher age at HCT was a predictor for both aGVHD (P = .001) and chronic GVHD (P = .01). The use of a mismatched donor was a predictor for aGVHD (P = .01). Higher rates of full-donor chimerism were achieved in successfully transplanted UCB recipients compared with MSD/MUD (P = .002). If complying with the international HCT guidelines, HCT in MPS patients results in high safety and efficacy. This allows extension of HCT to more attenuated MPS types. Because a younger age at HCT is associated with reduction of HCT-related toxicity, newborn screening may further increase safety.

Echocardiographic study of paediatric patients with mucopolysaccharidosis.

PRINCIPLE: Mucopolysaccharidosis is an inborn error of metabolism causing glucosaminoglycans tissue storage. Cardiovascular involvement is variable but contributes significantly towards the morbidity and mortality of the patients. OBJECTIVE: To characterise the echocardiographic abnormalities in children and adolescents with different types of mucopolysaccharidosis. METHOD: Echocardiograms and medical records of 28 patients aged 2-14 years, seen from 2003 to 2005, were revised. At that time, the enzymatic replacement therapy was still not available in our institution. RESULTS: Echocardiographic alterations were detected in 26 patients (93%), whereas 16 (57%) had abnormal auscultation, and only 6 (21%) presented with cardiovascular complaint. Mitral valve thickening with dysfunction (regurgitation, stenosis, or double lesion) was diagnosed in 60.8%, left ventricular hypertrophy in 43% and aortic valve thickening with regurgitation in 35.8% of the patients. There was no systolic dysfunction and mild left diastolic dysfunction was shown in 21.5% of the patients. Pulmonary hypertension was present in 36% of the patients, causing the only two deaths recorded. There was a strong association between the accumulation of dermatan sulphate and the presence of mitral valve dysfunction (p = 0.0003), aortic valve dysfunction (p = 0.006), and pulmonary hypertension (p = 0.006). Among individuals with two or more examinations, 82% had a worsening evolution. CONCLUSIONS: Echocardiographic alterations in children with Mucopolysaccharidosis are frequent and have a progressive character. Left valve lesions, ventricular hypertrophy, and pulmonary hypertension were the most common findings and there was an association between the accumulation of dermatan sulphate and cardiovascular involvement. Unlike in adults, pulmonary hypertension was the main cause of death, not left ventricle systolic dysfunction.

Transplant outcomes in mucopolysaccharidoses.

The mucopolysaccharidoses (MPSs) are inherited metabolic disorders (IMDs) caused by single-gene defects leading to progressive cellular accumulation of glycosaminoglycans (GAGs) and damage to multiple organs, including the central nervous, musculoskeletal, cardiorespiratory, and other systems. Hurler syndrome (MPS IH), the most severe form, is the prototypical model. Enzyme replacement therapy (ERT), available for MPS I, II, and VI, is beneficial in some patients. However, ERT does not improve neurocognitive function because of its inability to cross the blood-brain barrier. In contrast, allogeneic hematopoietic stem cell transplantation (HSCT) allows donor-derived, enzyme-producing cells to migrate to the brain and other organs to provide permanent enzyme therapy and thus help somatic organs, improve neurocognitive function and quality of life, and prolong survival, particularly when performed early in the course of the disease. Bone marrow has been the graft source in the past. However, in the last 5 years many patients have been treated with unrelated donor (URD) umbilical cord blood transplant (UCBT), allowing rapid and increased access to transplantation with favorable outcomes. This review describes published and our institutional clinical experiences, discusses the current status of the field, and provides therapy guidelines for patients with MPS.

Incidence of the mucopolysaccharidoses in Northern Ireland.

An epidemiological study of the mucopolysaccharidoses (MPS) in Northern Ireland using multiple ascertainment sources was carried out and the incidence rate for the period 1958-1985 was estimated. An incidence of approximately 1 in 76,000 live births was obtained for MPS 1H (Hurler phenotype); 1 in 280,000 for MPS 1 H/S (Hurler/Scheie phenotype); 1 in 140,000 live births (1 in 72,000 male live births) for MPS II (Hunter syndrome); 1 in 280,000 for MPS III (Sanfilippo syndrome) and 1 in 76,000 for MPS IV A (Morquio syndrome type A). No cases of MPS IS (Scheie phenotype), MPS IV B (Morquio syndrome type B) or MPS VI (Maroteaux-Lamy syndrome) were ascertained during the study period. Three cases of non-immune hydrops fetalis born to consanguineous parents were thought to be due to beta-glucuronidase deficiency (MPS VII) on the basis of placental histology and enzyme studies on both parents but no living cases of MPS VII were ascertained. The overall incidence for all types of mucopolysaccharidosis was approximately 1 in 25,000 live births. A comparison is made with incidence estimates obtained from other published studies.

Children with mucopolysaccharidosis: perioperative care, morbidity, mortality, and new findings.

The perioperative care, morbidity, and mortality in 30 patients with mucopolysaccharidosis (MPS) are presented. They underwent a detailed preoperative assessment and were anesthetized 141 times. An intravenous induction technique was used in most patients. It was easier to see the vocal cords, during laryngoscopy, in children with Hurler syndrome (HS) when they were younger (23 v 41 months, P < or = .01) and smaller (12 v 15 kg, P < or = .05). Preoperative obstructive breathing was associated with a significantly higher incidence of postextubation obstruction (P < or = .05). A total of 28 children underwent bone marrow transplantation (BMT); this reversed upper airway obstruction and also reversed intracranial hypertension. In children with HS, the incidence of odontoid dysplasia was 94%; 38% demonstrated anterior C1-C2 subluxation. Head and neck manipulation was limited in children with cervical spine defects. None of the 30 patients experienced spinal cord morbidity. One child suffered an intraoperative stroke; another, pulmonary edema. Severe and extensive coronary obstruction was responsible for 2 intraoperative deaths. Coronary angiography underestimated coronary artery disease.

A survey of signs, symptoms and symptom control in 30 terminally ill children.

The notes of 30 terminally ill children with various diagnoses were searched for reports of symptoms that had occurred during their last month of life. All had stayed at Helen House, a hospice for children, for part or all of that time. The results were analysed for symptom frequency and resistance to treatment. Over four-fifths of the children were recorded as having pain in the last month of life. In a smaller number, symptoms such as muscle spasm and excessive secretions proved particularly difficult to control. The identification of symptoms in brain-damaged and young children, and the control of some of the more resistant symptoms, are discussed.

Respiratory complications of mucopolysaccharide storage disorders.

Twenty-one patients with the diagnosis of mucopolysaccharidosis or mucolipidosis and a history of respiratory complaints or thorough respiratory evaluation were studied retrospectively. Anatomic factors affecting respiratory status included: (i) upper airway narrowing by hypertrophied tongue, tonsils, adenoids, and mucous membranes; (ii) lower airway narrowing by glycosaminoglycan deposition within the tracheobronchial mucosa; (iii) decreased thoracic dimensions due to scoliosis and thoracic hyperkyphosis; and (iv) decreased abdominal dimensions due to lumbar hyperlordosis, gibbus formation and hepatosplenomegaly. Cardiac and neurologic involvement, while present, did not play primary roles in the development of respiratory disease. The functional consequences of these findings included increased risk of developing: (i) respiratory tract infections; (ii) airway compromise during or after anesthesia or sedation; (iii) dyspnea on exertion; (iv) obstructive lung disease; (v) obstructive sleep apnea; and (vi) cor pulmonale. A management approach is presented which can reduce the morbidity and mortality experienced by these patients.