Initiation Of Enzyme Replacement Therapy Research Articles

#636 A phase 4, open label, multicenter prospective study of the safety and efficacy of agalsidase beta in Chinese patients with Fabry disease

Abstract Background and Aims Fabry disease (FD) is a rare inherited lysosomal storage disease caused by pathogenic GLA gene variants which result in a deficiency of the enzymatic activity of α-galactosidase A. Enzyme replacement therapy (ERT) is the mainstay of FD-specific treatment, but there are currently no reported clinical trials of ERT for FD in the Chinese population. This is the first phase 4 study to evaluate the safety and efficacy of ERT for FD in China since the approval of agalsidase beta in China in 2019. Method A 54-week, phase 4, open label, single arm, prospective, post-marketing surveillance (PMS) study of agalsidase beta (NCT05054387) was performed at 6 sites in China. Twenty-two Chinese ERT-naïve FD participants (≥8 years) with estimated glomerular filtration rate (eGFR) ≥30 mL/min/1.73 m2 were enrolled and received infusions of agalsidase beta (Fabrazyme®, Sanofi) at a dose of 1.0 mg/kg every 2 weeks for up to 48 weeks. The primary endpoint was safety and tolerability of agalsidase beta. The endpoints of clinical efficacy included the changes of plasma globotriaosylceramide (GL-3), globotriaosylsphingosine (Lyso-GL-3), FD symptoms (including angiokeratoma, hypohidrosis, anhidrosis, abdominal pain, headache, tinnitus, heat tolerance, and activity tolerance), and eGFR from baseline to week 48. A post-hoc subgroup analysis was conducted to explore the differences in ERT efficacy between two subgroups of different ages (<30 years and ≥30 years). Results All 22 patients completed the study intervention. There were 18 males (81.8%) and the mean age of ERT initiation was 29.0 ± 13.5 years. Treatment-related adverse events (AEs) and infusion-associated reactions (IARs) were reported in 8 participants (36.4%), which was less than ∼60% as previously reported for IARs. Most AEs were mild or moderate and no AE caused permanent treatment discontinuation or death. The mean plasma GL-3 and Lyso-GL-3 levels decreased remarkably at week 6 and remained stable throughout the trial, with the mean percentage reduction from baseline to week 6 through week 48 ranged from −34.6% ± 27.4% to ­41.9% ± 14.9% and −58.8% ± 20.2% to ­64.9% ± 12.7%, respectively (Fig. 1a and b). The reduction was more remarkable for the classic male patients (n = 18; GL-3: 7.99 ± 2.19 ug/mL at baseline and 4.31 ± 1.71 ug/mL at week 48, −46.0% ± 18.4%; Lyso-GL-3: 83.11 ± 25.69 ng/mL at baseline and 25.89 ± 13.43 ng/mL at week 48, −67.8% ± 17.6%). Thirteen (59.1%) participants experienced improved FD symptoms at week 48, with no cases of worsening symptoms. The mean eGFR was 115.6 ± 37.3 mL/min/1.73 m2 at baseline and 118.4 ± 42.9 mL/min/1.73 m2 at week 48, with a change of 0.0 ± 12.4 mL/min/1.73 m2 from baseline to week 48 (Fig. 1c). In the subgroup analysis, participants were divided into the younger group with age <30 years (n = 11) and the older group with age ≥30 years (n = 11) according to their age of ERT initiation. At week 48, the reduction of mean plasma GL-3 (−47.1% ± 23.6% vs −22.0% ± 26.0%) and Lyso-GL-3 levels (−72.4 ± 17.3% vs −48.2% ± 19.8%), the stabilization of renal function (the mean change of eGFR from baseline to week 48: 5.2 ± 7.9 mL/min/1.73 m2 vs −5.2 ± 14.1 mL/min/1.73 m2) and the percentage of symptom improvement (81.8% vs. 36.4%) were generally more remarkable in the younger group than in the older group (Table 1). Conclusion This first phase 4 study of ERT for Fabry disease in China demonstrates that agalsidase beta is safe and well tolerated with a relatively low IAR rate, and effective in reducing plasma GL-3 and Lyso-GL-3, improving symptoms, and stabilizing renal function in Chinese patients with FD. Furthermore, the present study implies that patients who initiate ERT at a younger age benefit more from the therapy. Funding: Commercial support - Sanofi Pharmaceuticals.

THE GLA D313Y MUTATION IN FABRY DISEASE: DIAGNOSTIC DILEMMAS AND THERAPEUTIC CONSIDERATIONS

Abstract Fabry disease is a genetic disorder caused by mutations in the GLA gene, which encodes alpha–galactosidase A, leading to enzyme dysfunction and subsequent accumulation of glycosphingolipids. In the classical form, it occurs in childhood or early adolescence with renal, cardiac, and neurological involvement, resulting in a poor prognosis. The GLA D313Y is a missense mutation resulting in a significant reduction of enzyme activity in plasma, while leukocyte enzyme activity remains within normal limits, leading to a "pseudo–deficiency" of enzyme activity with uncertain pathogenicity. In literature, it has been observed that individuals with this mutation may present predominantly with central neurologic manifestations, characterized by multifocal white matter lesions. Historically they do not receive indications for initiating enzyme replacement or molecular chaperone therapies. We present the case of a man affected by arterial hypertension and history of chronic lower limb pain who experienced a lacunar stroke at the age of 35. The GLA D313Y mutation was identified and enzyme activity assay in plasma was within normal limits, precluding the initiation of enzyme replacement therapy. Over the following years, he suffered two additional ischemic strokes, a progressive decline in renal function to stage 3, and acute coronary syndrome. Transthoracic echocardiography revealed hypertrophic non–obstructive cardiomyopathy (SIVd 20 mm) with normal biventricular ejection fraction. Cardiac magnetic resonance showed late gadolinium enhancement of inferior junctional and inferior wall in middle segment (Fig.1). Considering the patient‘s clinical conditions involving multi–organ impairment, an enzymatic activity test was performed on leukocytes, revealing a reduced activity. This prompted the decision to initiate enzyme replacement therapy. This case report supports the hypothesis that the D313Y mutation may be associated with a later presentation and not only neurological involvement. In our experience, it’s mandatory to proceed with the determination of leukocyte enzyme activity in presence of normal enzyme activity in plasma. As an alternative, the detection of glycosphingolipids’ accumulation could be useful, but myocardial and renal biopsy poses a high bleeding risk, especially in anticoagulated or antiaggregated patients. The authors propose considering the initiation of therapy in patients with the D313Y mutation who exhibit significant organ involvement.

Patrones de seguimiento y manejo clínico multidisciplinario en pacientes con Mucopolisacaridosis tipo IVA en Colombia

Background: There is limited data on the follow-up and management of patients with mucopolysaccharidosis IVA (MPS-IVA) undergoing enzyme replacement therapy (ERT) in Colombia. Objective: We aim to assess the real-world data of patients with MPS-IVA undergoing ERT in Colombia to understand patient profiles, follow-up patterns, and treatment dynamics. Methods: A convenience sample of geneticists and pediatric neurologists were recruited from November-2020 to January-2021. The physicians responded to a questionnaire-based report for each patient under their care regarding the patient profiles, follow-up patterns, and treatment dynamics. Results: A total of 24 physicians (geneticists [92%] and pediatric neurologists [8%]) provided data on 107 patients with MPS-IVA. Patients were diagnosed through molecular (36%) and/or enzymatic assays (97%). The mean age of patients was 19.5 years and 51% were male. The average time from first symptom to diagnosis was 7.1 years. The mean age at first symptoms was 4 years and at diagnosis was 11 years, further, the mean age at first ERT was 15 years. There was an increase in assessments after ERT initiation; parameters most frequently evaluated were weight, height, and echocardiography; quality of life, 6MWT, and 3-minute stair-climb test were the least frequent. ERT interruptions >2 months were observed in 63% patients. Conclusions: Monitoring of MPS-IVA patients receiving ERT remains suboptimal in Colombia. Establishing national management guidelines and implementing centralized reference centers, where patients can receive comprehensive care are warranted for ensuring appropriate systems, services, and support as a priority, with a potential positive effect in the course of the disease.

Modern Approach to Fabry Disease Diagnosis and Management in Children

Fabry disease (FD), or Andersen-Fabry disease, is a rare hereditary lysosomal disease (sphingolipids storage disease) characterized by progressive multisystem involvement. The major symptoms among children are neuropathic pain / acroparesthesia, angiokeratomas, hypo- or anhidrosis, vortex keratopathy. Biochemical tests, molecular genetic testing, and family screening play crucial role in the diagnosis of the disease. Specific pathogenetic treatment of FD includes enzyme replacement therapy (ERT) with recombinant medications of the lysosomal enzyme -galactosidase A. ERT initiation before the development of severe organs and systems’ damage contributes to its higher efficacy. This article covers various aspects of pathogenesis, clinical picture features in childhood, modern methods of diagnosis and management of FD according to literature data.

Idursulfase Beta (Hunterase) Therapeutic Experience in a Patient with Mucopolysaccharidosis Type II

Background. Mucopolysaccharidosis type II (MPS II, Hunter syndrome) is an X-linked recessive disease caused by lysosomal enzyme iduronate-2-sulfatase deficiency resulting in progressive glycosaminoglycans (GAG) accumulation in tissues (dermatan sulfate and heparan sulfate). GAG accumulation in cells leads to the development of progressive pathological disorders, malfunction of various organs and systems, early disability, and decrease in life expectancy. Enzyme replacement therapy (ERT) reduces the rate of life-threatening conditions development in patient. ERT would be more effective if it is prescribed early, especially at preclinical stage. This is the time when there are no severe irreversible changes in the cell, thus, pathogenetic therapy will decrease GAG accumulation in lysosomes, slow down the pathological process, and improve patient's condition. Clinical case description. Male patient diagnosed with MPS II was administrated with ERT idursulfase beta at the age of 6 months. It led to milder disease course compared to proband uncle who had similar mutation in the IDS gene, severe disease phenotype, and later initiation of ERT (at the age of 2.5 years). Conclusion. Early ERT initiation in patients with MPS II significantly slows down development of severe and life-threatening complications, increases the duration and improves the quality of life.

Multidisciplinary treatment in the long-term management of Fabry disease

Fabry disease is a rare X-linked hereditary condition caused by mutations in the α-galactosidase A (GLA) gene, resulting in decreased α-GAL A enzyme activity. The clinical manifestations of Fabry disease are diverse, which leads to delays in diagnosis and treatment, thereby increasing the disease burden for patients and their families. Given its characteristics, multidisciplinary treatment (MDT) is critical for the long-term management of Fabry disease, and should include nephrology departments, cardiovascular departments, neurology departments, and pediatric department, among others. This study focuses on early screening for Fabry disease, the indication for initiating enzyme replacement therapy, pre-treatment evaluation, and monitoring to provide practical guidance for Chinese clinicians.

Impact of kidney biopsy on deciding when to initiate enzyme replacement therapy in children with Fabry disease

BackgroundRecommendations on when to start enzyme replacement therapy (ERT) in children with Fabry disease (FD) differ between guidelines. In this study, kidney biopsies of a cohort of 14 untreated children and one treated child were analyzed for their morphologic changes to determine whether early initiation of ERT is indicated.MethodsAll pediatric FD patients (< 18 years old) diagnosed between 2003 and 2021 in our department who received a kidney biopsy were enrolled. Clinical symptoms; laboratory parameters regarding kidney function, such as eGFR, plasma urea, protein-creatinine, and albumin/creatinine ratio; and 14 kidney biopsies prior to ERT and one under treatment were retrospectively analyzed.ResultsA total of 14 patients were enrolled, including 9 male and 5 female children, aged 3–18 years (median age 11). Seven of the enrolled children were 10 years old or younger. Histological analysis of kidney biopsy samples revealed severe vacuolization and accumulation of inclusions in podocytes and renal tubules. The majority of cases had no FD-specific clinical or laboratory features independent of age, gender, or genotype. The youngest FD patient presenting with isolated abnormal kidney biopsy was 3 years old.ConclusionsWe demonstrate that histological lesions, typical for FD, can be observed in kidney biopsies at a very young age in patients without classical clinical symptoms or laboratory abnormalities. Thus, we recommend kidney biopsies as a possible tool for early diagnosis of renal involvement in FD. As a consequence of these early biopsy findings without a clinical correlate, an early initiation of ERT should be considered.Graphical abstractA higher resolution version of the Graphical abstract is available as Supplementary information

Clinical Profiles of Children with Hypophosphatasia prior to Treatment with Enzyme Replacement Therapy: An Observational Analysis from the Global HPP Registry

Introduction: The objective of this study was to better understand the clinical profiles of children with hypophosphatasia (HPP) prior to treatment with enzyme replacement therapy (ERT). Methods: Pretreatment demographics and medical histories of ERT-treated children (aged <18 years) enrolled in the Global HPP Registry (2015–2020) were analyzed overall, by age at first HPP manifestation (<6 months vs. 6 months to 18 years), and by geographic region (USA/Canada, Europe, and Japan). Results: Data from 151 children with HPP were analyzed. Sex distribution was balanced overall (52.3% female; 47.7% male) but differed in Japan (63.0% female; 37.0% male). Prior to ERT initiation, common manifestations were skeletal (67.5%) and extraskeletal, with the foremost types being muscular (48.3%), constitutional/metabolic (47.0%), and neurologic (39.7%). A high proportion of children who first presented at <6 months of age (perinatal/infantile period) had a history of bone deformity (59.3%) and respiratory failure (38.3%), while those aged 6 months to 18 years at first manifestation had a predominance of early loss of primary teeth (62.3%) and gross motor delay (41.0%). Those from Japan were reported to have a younger median age overall, the highest proportion of skeletal manifestations (80.4%) and growth impairment, while European data reported the highest proportion of muscular manifestations (70.7%). In the USA/Canada, skeletal and muscular manifestations were reported at the same frequency (57.4%). Conclusion: Prior to ERT, skeletal and extraskeletal manifestations were commonly reported in children with HPP, with differences by age at first HPP manifestation and geographical region. Comprehensive assessments of children with HPP are warranted prior to ERT initiation.

Effects of enzyme replacement therapy on bone density in late onset Pompe disease

Pompe disease is an autosomal recessive disorder caused by a deficiency of α-glucosidase, resulting in the accumulation of glycogen in smooth, cardiac, and skeletal muscles, leading to skeletal muscle dysfunction, proximal muscle weakness, and early respiratory insufficiency. Although many patients exhibit decreased bone mineral density (BMD) and increased fractures, there is currently no official protocol for surveillance and management of osteoporosis and osteopenia in late onset Pompe disease (LOPD). Enzyme replacement therapy (ERT) has therapeutic effects on muscle function; however, very few studies report on the effect of ERT on bone mineralization in LOPD patients. Our study included 15 Pompe patients from 25 to 76 years of age on ERT for variable durations. Progressive impact of ERT on BMD of the hips and spine, and the frequency of osteopenia or osteoporosis was studied using DEXA scanning, and correlations were made with age of initiation of ERT, duration of ERT and six-minute walk test. We found a significant positive correlation between the age of ERT initiation and age of the subject, with increases in the Z-scores for the femur and lumbar region. Females had a significantly higher risk for developing osteoporosis compared to males. These results highlight the significance of ERT on reducing progression of osteoporosis in LOPD patients.

Outcome of BCG Vaccination in ADA-SCID Patients: A 12-Patient Series.

Vaccination with Bacillus Calmette-Guérin (BCG) can be harmful to patients with combined primary immunodeficiencies. We report the outcome of BCG vaccination in a series of twelve patients affected by adenosine deaminase deficiency (ADA-SCID). BCG vaccination resulted in a very high incidence of complications due to uncontrolled replication of the mycobacterium. All patients who developed BCG-related disease were treated successfully and remained free from recurrence of disease. We recommend the prompt initiation of enzyme replacement therapy and secondary prophylaxis to reduce the risk of BCG-related complications in ADA-SCID patients.

Clinical features and enzyme replacement therapy in 10 children with Fabry disease.

To summarize the clinical features, diagnosis and enzyme replacement therapy(ERT) of Fabry disease (FD) in children. The clinical data, laboratory tests, genetic variations and treatment of 10 FD children diagnosed in Shandong Provincial Hospital from September 2020 to June 2022 were retrospectively analyzed. Among the 10 cases from 6 families, 7 patients were boys of 4 to 13 years of age, and 3 were girls of 12 to 15 years of age. There were 7 symptomatic patients, including 6 boys and 1 girl. All 7 patients presented with acral neuralgia. Five patients had little or no sweating. Five patients presented with cutaneous angiokeratoma. Two patients had abdominal pain. One patient developed joint symptoms. Four patients had corneal opacity. One patient had hearing loss; one patient had short stature. One patient had mild proteinuria and 1 patient had dysplasia of the right kidney with decreased eGFR (55.28 ml/min.1.73 m2). The left ventricular mass index was slightly elevated in 1 patient. Three patients had mild obstructive ventilatory dysfunction; a small amount of effusion in the intestinal space of the lower abdomen or mild fatty liver was found in 2 patients. Partial empty sella turcica in 1 patient. A total of 6 GLA gene variants were detected in 10 children, among which C.1059_1061delGAT (p.met353del) was a newly discovered mutation. Five children received ERT, of which 4 were treated with agalsidase beta and 1 was treated with agalsidase alpha. Only 1 patient had anaphylaxis. Lyso-GL-3 levels decreased significantly in the first 3 months of ERT initiation and remained relatively stable thereafter in 3 patients. The Lyso-GL-3 level was decreased, but renal impairment continued to progress in 1 patient treated with agalsidase alpha. The clinical manifestations of FD in childhood are diverse, and it is necessary to make a definite diagnosis by combining family history, enzyme activity, biomarkers, gene testing and other indicators. Pedigree screening and high-risk population screening are helpful for early identification, early diagnosis and early treatment. No serious adverse reactions were found during the short-term treatment with agalsidase alpha and beta.

Mucopolysaccharidosis type 4 (Morquio syndrome): A case report

Abstract Introduction Mucopolysaccharidosis (MPS) IVA (Morquio syndrome) is a rare lysosomal storage disease, that is caused by a deficiency in the enzyme N-acetylgalactosamine-6-sulfatase (GALNS) due to an autosomal recessive mutation in the GALNS gene. Herein, we present a MPS IVA case without regular follow-up, whose enzyme replacement was planned to start at age 30 for the first time, so as to attract attention to this rare disease. Clinical Case A 30-year-old female patient diagnosed with MPS IVA, that was evaluated due to corneal clouding referred to the Marmara University endocrinology outpatient clinic for enzyme replacement. On admission, she complains of impaired vision, hearing loss, hypoglycemic symptoms and numbness of hands and feet. While she was normal for about 2 years after birth, she was noticed for delays in crawling and walking from 2–3 year of age. However, she had definitive diagnosis of MPS-IVA at the age of 9 years, with low enzymatic analysis and genetic mutation in the GALNS gene located on chromosome 16q24.3. She operated on for bilateral glaucoma and cerebellar mass when she was 17. Her parents were third degree consanguineous, and she had one healthy younger brother. On physical examination, blood pressure: 99/67 mmHg, pulse: 72/min, temperature: 36°C, SpO2:99. She was in a wheelchair. Her height was 92 cm, weight was 30 kg, BMI: 25.6 kg/m2. Disproportionate short stature, coarse facial features, hypertelorism, genu valgum, pectus carinatum, kyphoscoliosis, were detected. Her neuromotor development was normal. Laboratory findings were unremarkable except for vitamin D hypovitaminosis. Radiographic findings were dysostosis multiplex, include abnormally shaped vertebral bodies with anterior beaking, posterior scalloping, platyspondyly and dens hypoplasia, thoracolumbar kyphosis, short, broad metacarpals, acetabular dysplasia, genu valgum, pectus carinatum, paddle-shaped ribs and short, and thick clavicles (Fig 1). Bone densitometry results were in osteoporotic range BMD at the femoral neck was 0.491 g/cm2, Z score was -2.8 and at the lumbar spine was 0.707 g/cm2, Z score was -3.6. She continued the 6-min walk test with the help of a walker and knee pad for 2.37 minutes and walked 3.4 meters. Echocardiography demonstrated that ejection fraction was 65%, normal left ventricular systolic function, no ventricular segmental wall motion defect, aortic 3 cusps, mild to moderate aortic valvular regurgitation, mild mitral valvular regurgitation. Pectus carinatum was detected on thorax CT imaging, whereas a restrictive disease pattern was not observed in PFT and DLCO. Bilateral severe mixed hearing loss was detected. Recombinant human GALNS (elosulfase alfa), 2.0 mg/kg/week, was planned to administer IV in 4 hr. Conclusion Because of the progressive nature of MPS- IVA, early diagnosis and early initiation of enzyme replacement therapy are critical to prevent cumulative systemic manifestations of the patient, especially the skeletal system.

Clinical Characteristics of a Patient with Mucopolysaccharidosis Type IVA (Morquio Syndrome)

Mucopolysaccharidosis (MPS) type IVA (Morquio syndrome) is a hereditary lysosomal storage disease caused by deficiency of N-acetylglucosamine-6-sulfate sulfatase. This enzyme deficiency leads to specific glycosaminoglycans (keratan sulfate and chondroitin-6sulfate) accumulation mainly in the bone and cartilage tissues, as well as in the cardiovascular, respiratory systems, and visual systems. Patients with MPS IVA look healthy at birth, however, they develop typical spine deformities (kyphoscoliosis), pectus carinatum, wrists hypermobility with decreased muscle strength and loss of fine motor skills, valgus deformation of lower limbs during the first years of life. Pathological changes in cardiovascular and respiratory systems, visual and acoustic analyzers can be revealed. Early diagnosis of the disease is crucial for timely initiation of enzyme replacement therapy. Thus, low incidence of the disease and its heterogeneous clinical picture complicates diagnosis. Consequently, patients with MAS IVA often become severely disabled as early as adolescence. Patients with severe form and without treatment die before the age of 30 due to complications of respiratory system diseases, valvular heart apparatus involvement, and cervical myelopathy.

Airway Findings in Patients with Hunter Syndrome Treated with Intravenous Idursulfase.

People with Hunter syndrome are known to be affected by a variety of airway pathologies. Treatment of Hunter syndrome with the enzyme replacement therapy (ERT) idursulfase is now the standard of care. However, it is not known how ERT changes the progression of airway involvement. To evaluate this, we performed a retrospective analysis of bronchoscopies performed on children with Hunter syndrome who were part of intrathecal ERT trials. Findings for airway pathology were extracted from bronchoscopy reports and analyses were performed for cross-sectional and longitudinal changes in airway disease. One-hundred and thirty bronchoscopies from 23 subjects were analyzed. Upper airway disease (adenoid hypertrophy and/or pharyngomalacia) was reported in 93% and 87% of bronchoscopies, respectively. Laryngeal abnormalities were recognized in 46% of cases. There were lower airway (tracheal and or bronchial) findings in 64% of all bronchoscopies and prevalence increased with age. Evaluations over time adjusted for repeat evaluations showed that increasing airway involvement was associated with older age (p = 0.0007) despite ongoing ERT. No association was discovered between age of intravenous ERT initiation and progression of airway disease. Individuals with Hunter syndrome who are receiving intravenous enzyme replacement therapy showed the progression of airways disease supporting the need for regular airway monitoring and intervention.

Left atrial strain correlates with severity of cardiac involvement in Anderson-Fabry disease

ObjectivesCardiac involvement in Anderson-Fabry disease (AFD) results in myocardial lipid depositions. An early diagnosis can maximize therapeutic benefit. Thus, this study aims to investigate the potential of cardiac MRI (CMR) based parameters of left atrial (LA) function and strain to detect early stages of AFD.MethodsPatients (n = 58, age 40 (29–51) years, 31 female) with genetically proven AFD had undergone CMR including left ventricular (LV) volumetry, mass index (LVMi), T1, and late gadolinium enhancement, complemented by LA and LV strain measurements and atrial emptying fractions. Patients were stratified into three disease phases and compared to age and sex-matched healthy controls (HC, n = 58, age 41 [26–56] years, 31 female).ResultsA total of 19 early-, 20 intermediate-, and 19 advanced-phase patients were included. LV and LA reservoir strain was significantly impaired in all AFD phases, including early disease (both p < 0.001). In contrast, LA volumetry, T1, and LVMi showed no significant differences between the early phase and HC (p > 0.05). In the intermediate phase, LVMi and T1 demonstrated significant differences. In advanced phase, all parameters except active emptying fractions differed significantly from HC. ROC curve analyses of early disease phases revealed superior diagnostic confidence for the LA reservoir strain (AUC 0.88, sensitivity 89%, specificity 75%) over the LV strain (AUC 0.82).ConclusionsLA reservoir strain showed impairment in early AFD and significantly correlated with disease severity. The novel approach performed better in identifying early disease than the established approach using LVMi and T1. Further studies are needed to evaluate whether these results justify earlier initiation of therapy and help minimize cardiac complications.Key Points• Parameters of left atrial function and deformation showed impairments in the early stages of Anderson-Fabry disease and correlated significantly with the severity of Anderson-Fabry disease.• Left atrial reservoir strain performed superior to ventricular strain in detecting early myocardial involvement in Anderson-Fabry disease and improved diagnostic accuracies of approaches already using ventricular strain.• Further studies are needed to evaluate whether earlier initiation of enzyme replacement therapy based on these results can help minimize cardiac complications from Anderson-Fabry disease.

Clinical phenotype and long-term outcome of patients with Anderson-Fabry disease followed at a multidisciplinary cardiomyopathy centre

Abstract Background Anderson-Fabry disease (AFD) is a rare genetic lysosomal storage disorder which often goes unnoticed until symptom onset requires aggressive treatment. Prompt diagnosis remains crucial. Dedicated multidisciplinary centres are a remarkable opportunity to develop early detection strategies and appropriate management. Purpose To describe the long-term outcomes of patients diagnosed with AFD followed at a Cardiomyopathy Referral Centre according to baseline phenotype (clinical involvement vs sub-clinical involvement). Methods All consecutive patients with AFD visited at our Cardiomyopathy Unit from 1989 to 2020 with &amp;gt;1-year follow-up were retrospectively reviewed. Clinical involvement was defined by one among left ventricular hypertrophy (LVH)&amp;gt;15mm, presence of conduction blocks or cardiac implantable electronic devices (CIED), atrial fibrillation, kidney disease (CKD), stroke or transient ischemic attack (TIA). The primary outcome was disease progression, defined as de novo CIED implantation, increased or de novo LVH, de novo Stroke/TIA, or progression of CKD. Of 110 patients diagnosed with AFD, 86 (78%) with &amp;gt;1-year follow-up were selected. Results Clinical involvement was present in 60 (70%) patients. Age at diagnosis was similar between patients with clinical and subclinical phenotype (42+17 vs 39+15, p=0.277). Patients with clinical involvement were more frequently men (N=25 [42%] vs 4 [15%], p=0.025) and probands (p=0.01). Overall, 1-organ involvement was present in 31 (52%) patients, 2-organ involvement in 24 (40%) patients and 3-organ in 5 (8%). A total of 46 (77%) patients were referred to enzyme replacement therapy (ERT): 52% received agalsidase α, 26% agalsidase β, and 22% migalastat. Among those with a clinical involvement not on ERT, 9 (15%) were scheduled for ERT initiation, 3 (5%) were considered old for ERT, 1 (1.5%) refused ERT and 1 (1.5%) had an allergic reaction to ERT. At 7 [3–12] years follow up, both study cohorts manifested signs and symptoms of disease progression: N=28 (47%) vs N=4 (15%), p=0.01, in patients with vs. without baseline clinical involvement, respectively. The main causes for diseases progression were increase (28%) or de novo LVH (13%), CKD (7%) and CIED implantation (5%). At Cox multivariable analysis, however, after adjustment for age at diagnosis, late onset phenotype and gender, the impact of clinical vs subliclinical involvement on disease progression was lost (Hazard Ratio 0.92, 95% C.I. 0.30–2.81). Conclusion Clinical involvement in AFD is frequent, irrespective of age at diagnosis, being present in more than 1-in-2 patients at baseline. Prompt referral to dedicated centres is warranted for appropriate care as the disease may progress in both patients with and without initial overt clinical phenotype despite optimal medical management. Funding Acknowledgement Type of funding sources: None.

Long-term outcomes of very early treated infantile-onset Pompe disease with short-term steroid premedication: experiences from a nationwide newborn screening programme

BackgroundStarting enzyme replacement therapy (ERT) before severe irreversible muscular damage occurs is important in infantile-onset Pompe disease (IOPD). This long-term follow-up study demonstrates our diagnostic and treatment strategies for IOPD...

Impact of the Timing of Enzyme Replacement Therapy Initiation and Cognitive Impairment Status on Outcomes for Patients with Mucopolysaccharidosis II (MPS II) in the United States: A Retrospective Chart Review.

Background: Mucopolysaccharidosis II (MPS II; Hunter syndrome; OMIM 309900) is a rare, X-linked, lysosomal storage disease caused by deficient iduronate-2-sulfatase activity. Accumulation of glycosaminoglycans results in multisystemic disease manifestations, which may include central nervous system involvement and cognitive impairment (CI). Patients with MPS II experience a high disease burden, leading to extensive healthcare resource utilization (HRU) and reduced quality of life.Objectives: This study aimed to assess the impact of timing of enzyme replacement therapy (ERT) initiation and CI status on the clinical characteristics and HRU of patients with MPS II.Methods: A retrospective medical chart review of 140 male patients who received a diagnosis of MPS II between 1997 and 2017 was performed at 19 US sites; data on disease manifestations and HRU stratified by age at ERT initiation or CI status were analyzed for the full study population and a subgroup of patients who received a diagnosis of MPS II before the age of 6 years.Results: In patients initiating ERT before 3 years of age, there was a trend toward lower symptom burden and HRU compared with patients who initiated ERT at an older age. Evaluation of developmental and behavioral signs and symptoms in the full study population showed that communication delay (70.0% of patients), cognitive delay (62.1%), behavioral problems (52.9%), and toileting delay (50.0%) were particularly common; earliest documented signs and symptoms were motor delay (median [range] age at first documentation: 4.2 [0.9-18.7] years) and behavioral problems (4.4 [0.6-13.7] years). Patients with CI generally experienced greater symptom burden and higher HRU than those without CI, with the most notable differences documented for communication and toileting delays. Formal cognitive testing was documented in <30% of cognitively impaired patients diagnosed with MPS II before the age of 6 years.Conclusions: Our findings reinforce previous recommendations for ERT to be initiated early to maximally benefit patients with MPS II, especially those younger than 3 years old. Cognitively impaired patients experience a particularly high disease burden and HRU. Patient care could be improved with early cognitive assessments and the development of treatments that address cognitive decline.

Growth in individuals with attenuated mucopolysaccharidosis type I during untreated and treated periods: Data from the MPS I registry.

Mucopolysaccharidosis Type I (MPS I) is caused by deficiency of α‐L‐iduronidase. Short stature and growth deceleration are common in individuals with the attenuated MPS I phenotype. Study objectives were to assess growth in individuals with attenuated MPS I enrolled in The MPS I Registry while untreated and after initiation of enzyme replacement therapy (ERT) with laronidase (recombinant human iduronidase). Individuals in the MPS I Registry with at least one observation for height and assigned attenuated MPS I phenotype as of September 2020 were included. The cohort included 142 males and 153 females 2–18 years of age. Age and sex adjusted standardized height‐for‐age z‐scores during the natural history and ERT‐treatment periods were assessed using linear mixed model repeated measures analyses. Growth curves were estimated during both periods and compared to standard growth charts from the Center for Disease Control (CDC). There was a significantly slower decline in height z‐scores with age during the ERT‐treated period compared to the natural history period. Estimated average height z‐scores in the ERT‐treatment versus the natural history period at age 10 were −2.4 versus −3.3 in females and −1.4 versus −2.9 in males (females first treated 3 year; males <4.1 year). While median height remained below CDC standards during both the natural history and ERT‐treated periods for individuals with attenuated MPS I, laronidase ERT was associated with slower declines in height z‐scores.

Newborn Screening Program for Mucopolysaccharidosis Type II and Long-Term Follow-Up of the Screen-Positive Subjects in Taiwan.

Background: Mucopolysaccharidosis II (MPS II) is an X-linked disorder resulting from a deficiency in lysosomal enzyme iduronate-2-sulfatase (IDS), which causes the accumulation of glycosaminoglycans (GAGs) in the lysosomes of many tissues and organs, leading to progressive cellular dysfunction. An MPS II newborn screening program has been available in Taiwan since 2015. The aim of the current study was to collect and analyze the long-term follow-up data of the screen-positive subjects in this program. Methods: From August 2015 to April 2022, 548,624 newborns were screened for MPS II by dried blood spots using tandem mass spectrometry, of which 202 suspected infants were referred to our hospital for confirmation. The diagnosis of MPS II was confirmed by IDS enzyme activity assay in leukocytes, quantitative determination of urinary GAGs by mass spectrometry, and identification of the IDS gene variant. Results: Among the 202 referred infants, 10 (5%) with seven IDS gene variants were diagnosed with confirmed MPS II (Group 1), 151 (75%) with nine IDS gene variants were classified as having suspected MPS II or pseudodeficiency (Group 2), and 41 (20%) with five IDS gene variants were classified as not having MPS II (Group 3). Long-term follow-up every 6 months was arranged for the infants in Group 1 and Group 2. Intravenous enzyme replacement therapy (ERT) was started in four patients at 1, 0.5, 0.4, and 0.5 years of age, respectively. Three patients also received hematopoietic stem cell transplantation (HSCT) at 1.5, 0.9, and 0.6 years of age, respectively. After ERT and/or HSCT, IDS enzyme activity and the quantity of urinary GAGs significantly improved in all of these patients compared with the baseline data. Conclusions: Because of the progressive nature of MPS II, early diagnosis via a newborn screening program and timely initiation of ERT and/or HSCT before the occurrence of irreversible organ damage may lead to better clinical outcomes. The findings of the current study could serve as baseline data for the analysis of the long-term effects of ERT and HSCT in these patients.