Clinical and economic justification of screening for mucopolysaccharidosis type I in children at groups of risks

Author(s):  
I. S. Krysanov ◽  
V. S. Krysanova ◽  
V. Yu. Ermakova

Background. Mucopolysaccharidosis Type I (MPS I) has clinical heterogeneity without specific symptoms leading to difficulties with diagnostic on time. In-depth screening for MPS I in children has aim of early detection and timely treatment with an enzyme replacement therapy. Aim. The purpose of this study was to conduct a clinical and economic assessment of the feasibility of screening for MPS I in children at group of risks. Materials and methods. Model for evaluation of the social-economic burden of MPS I with calculation of expenditures has been created. Costs of diagnosed and non-diagnosed patients in group of risks were identified, including direct medical costs (pharmacotherapy, out-patient cure, hospital admission, complications treatment, hematopoietic stem cell transplantation; direct non-medical (payments for disability); indirect (expenses related to the reduction or loss of the ability to work of one of the parents performing the duties of caring for a disabled child). Results. The weighted average cost per 1 diagnosed patient with mild forms of MPS I with selective screening, was 405,974.22 rubles, which is 184,421.85 rubles less vs average cost per 1 undiagnosed patient. The management and treatment of patients with mild forms of MPS I after selective screening will allow saving up to 17.7 million rubles/year, which would possible to additionally screen 705 patients. Taking into account the size of the population of patients with undiagnosed MPS I, currently the costs for this group amount to 56.7 million rubles, while the «overspend» of budget funds for untimely diagnosis of MPS I for this cohort of children is about 22.6 million rubles/year. Conclusion. Selective screening for MPS I in children at group of risks is economically proved and can lead to treatment on-time for disability and complications prevention.

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Augusto Magalhães ◽  
Ana Maria Cunha ◽  
Rodrigo Vilares-Morgado ◽  
Elisa Leão-Teles ◽  
Esmeralda Rodrigues ◽  
...  

Purpose. To describe retinal findings in a patient with mucopolysaccharidosis type I (MPS I) that underwent an early treatment with hematopoietic stem cell transplantation (HSCT) and enzyme replacement therapy (ERT). Case Report. We describe a case of a 12-year-old female with a biochemical and genetic diagnosis of MPS I. She underwent HSCT and ERT on the first year of life. The visual acuity was 5/10 in both eyes and she had bilateral grade 2 corneal haze. Spectral domain optical coherence tomography (SD-OCT) revealed thickening of the external limiting membrane (ELM) at the fovea. In the parafoveal and perifoveal regions, SD-OCT displayed a loss of the interdigitation, ellipsoid, and myoid zones and of the ELM accompanied by progressive thinning of the outer nuclear layer. Fundus infrared imaging revealed a hyperreflective ring centred on the fovea and hyporeflective areas in temporal parafoveal regions in both eyes. En face OCT imaging revealed two hyperreflective rings on the outer retinal level. Conclusion. This patient developed macular changes with foveal deposition of hyperreflective material and parafoveal thinning, despite early systemic treatment. Systemic therapies can provide an increase in life expectancy and stabilize visual acuity and corneal clouding, although their effect on retinal degeneration is unknown.


2020 ◽  
pp. archdischild-2020-319040 ◽  
Author(s):  
Roberto Giugliani ◽  
Nicole Muschol ◽  
Hillary A. Keenan ◽  
Mark Dant ◽  
Joseph Muenzer

ObjectiveEarly diagnosis and treatment initiation are important factors for successful treatment of mucopolysaccharidosis type I (MPS I). The purpose of this observational study was to assess whether age at diagnosis and time to first treatment for individuals with MPS I have improved over the last 15 years.Study designData from the MPS I Registry (NCT00144794) for individuals with attenuated or severe disease who initiated therapy with laronidase enzyme replacement therapy (ERT) and/or hematopoietic stem cell transplantation (HSCT) between 1 January 2003 and 31 December 2017 were included.ResultsData were available for 740 individuals with attenuated (n=291) or severe (n=424) MPS I (unknown n=25). Median age at diagnosis for attenuated disease did not change over time and ranged between 4.5 and 6 years of age while the median duration from diagnosis to first ERT decreased from 5.6 years before/during 2004 to 2.4 months in 2014–2017. For severe MPS I treated with HSCT, median age at diagnosis was less than 1 year and median time to first treatment was less than 3 months throughout the 15-year observation period.ConclusionsTimes to diagnosis and HSCT initiation for individuals with severe MPS I were consistent over time. For individuals with attenuated MPS I, the time to ERT initiation after diagnosis has improved substantially in the last 15 years, but median age at diagnosis has not improved. Efforts to improve early diagnosis in attenuated MPS I are needed to ensure that patients receive appropriate treatment at the optimal time.


Diagnostics ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 161 ◽  
Author(s):  
Francyne Kubaski ◽  
Fabiano de Oliveira Poswar ◽  
Kristiane Michelin-Tirelli ◽  
Ursula da Silveira Matte ◽  
Dafne D. Horovitz ◽  
...  

Mucopolysaccharidosis type I (MPS I) is caused by the deficiency of α-l-iduronidase, leading to the storage of dermatan and heparan sulfate. There is a broad phenotypical spectrum with the presence or absence of neurological impairment. The classical form is known as Hurler syndrome, the intermediate form as Hurler–Scheie, and the most attenuated form is known as Scheie syndrome. Phenotype seems to be largely influenced by genotype. Patients usually develop several somatic symptoms such as abdominal hernias, extensive dermal melanocytosis, thoracolumbar kyphosis odontoid dysplasia, arthropathy, coxa valga and genu valgum, coarse facial features, respiratory and cardiac impairment. The diagnosis is based on the quantification of α-l-iduronidase coupled with glycosaminoglycan analysis and gene sequencing. Guidelines for treatment recommend hematopoietic stem cell transplantation for young Hurler patients (usually at less than 30 months of age). Intravenous enzyme replacement is approved and is the standard of care for attenuated—Hurler–Scheie and Scheie—forms (without cognitive impairment) and for the late-diagnosed severe—Hurler—cases. Intrathecal enzyme replacement therapy is under evaluation, but it seems to be safe and effective. Other therapeutic approaches such as gene therapy, gene editing, stop codon read through, and therapy with small molecules are under development. Newborn screening is now allowing the early identification of MPS I patients, who can then be treated within their first days of life, potentially leading to a dramatic change in the disease’s progression. Supportive care is very important to improve quality of life and might include several surgeries throughout the life course.


Biomolecules ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 189
Author(s):  
Christiane S. Hampe ◽  
Jacob Wesley ◽  
Troy C. Lund ◽  
Paul J. Orchard ◽  
Lynda E. Polgreen ◽  
...  

Mucopolysaccharidosis type I (MPS I) is a lysosomal disease, caused by a deficiency of the enzyme alpha-L-iduronidase (IDUA). IDUA catalyzes the degradation of the glycosaminoglycans dermatan and heparan sulfate (DS and HS, respectively). Lack of the enzyme leads to pathologic accumulation of undegraded HS and DS with subsequent disease manifestations in multiple organs. The disease can be divided into severe (Hurler syndrome) and attenuated (Hurler-Scheie, Scheie) forms. Currently approved treatments consist of enzyme replacement therapy (ERT) and/or hematopoietic stem cell transplantation (HSCT). Patients with attenuated disease are often treated with ERT alone, while the recommended therapy for patients with Hurler syndrome consists of HSCT. While these treatments significantly improve disease manifestations and prolong life, a considerable burden of disease remains. Notably, treatment can partially prevent, but not significantly improve, clinical manifestations, necessitating early diagnosis of disease and commencement of treatment. This review discusses these standard therapies and their impact on common disease manifestations in patients with MPS I. Where relevant, results of animal models of MPS I will be included. Finally, we highlight alternative and emerging treatments for the most common disease manifestations.


2020 ◽  
Vol 58 (12) ◽  
pp. 2063-2072 ◽  
Author(s):  
Giulia Polo ◽  
Daniela Gueraldi ◽  
Antonella Giuliani ◽  
Laura Rubert ◽  
Chiara Cazzorla ◽  
...  

AbstractObjectivesMucopolysaccharidosis type I (MPS I) was added to our expanded screening panel in 2015. Since then, 127,869 newborns were screened by measuring α-L-iduronidase (IDUA) enzyme activity with liquid chromatography tandem mass spectrometry (LC-MS/MS). High false positives due to frequent pseudodeficiency alleles prompted us to develop a second-tier test to quantify glycosaminoglycan (GAG) levels in dried blood spot (DBS).MethodsHeparan-sulfate (HS) and dermatan-sulfate (DS) were measured with LC-MS/MS after methanolysis. DBSs were incubated with methanolic-HCl 3 N at 65 °C for 45 min. Chromatographic separation used an amide column with a gradient of acetonitrile and water with 10 mM ammonium acetate in a 9-min run. The method was validated for specificity, linearity, lower limit of quantification (LOQ), accuracy and precision.ResultsIntra- and inter-day coefficients of variation were <15% for both metabolites. Reference values in 40 healthy newborns were: HS mean 1.0 mg/L, 0–3.2; DS mean 1.5 mg/L, 0.5–2.7). The two confirmed newborn MPS I patients had elevated HS (4.9–10.4 mg/L, n.v. <3.2) and DS (7.4–8.8 mg/L, n.v. <2.7). Since its introduction in February 2019, the second-tier test reduced the recall rate from 0.046% to 0.006%. Among 127,869 specimens screened, the incidence was 1:63,935 live births. Both patients started enzyme replacement therapy (ERT) within 15 days of birth and one of them received allogenic hematopoietic stem cell transplantation (HSCT) at ht age of 6 months.ConclusionsGAGs in DBS increased the specificity of newborn screening for MPS I by reducing false-positives due to heterozygosity or pseudodeficiency. Early diagnosis and therapeutical approach has improved the outcome of our patients with MPS I.


2021 ◽  
Vol 12 (3) ◽  
pp. 69-83
Author(s):  
Victoria N. Gorbunova ◽  
Natalia V. Buchinskaia

Mucopolysaccharidosis (MPS) are a genetically heterogeneous group of rare monogenic metabolic diseases associated with hereditary insufficiency of lysosomal enzymes involved in the catabolism of glycosaminoglycans, or mucopolysaccharides. The pathogenesis of MPS is due to the accumulation of non-cleaved glycosaminoglycans in lysosomes, which can destroy cells. All MPS are characterized by a polysystemic manifestation, the simultaneous involvement of many organs and tissues in the pathological process, first of all, connective tissues, bones and cartilaginous. This review presents the epidemiology, clinical, biochemical, and molecular genetic characteristics of MPS types I and II, caused by the recessive mutations in the alpha-L-iduronidase and iduronate-2-sulfatase genes, respectively, and by the accumulation of dermatan and heparan sulfate. Each of these diseases is characterized by clinical polymorphism, especially observed in MPS I, which often manifests in a severe form of Hurler syndrome, but can also occur in a milder form of Scheie syndrome. Currently, there is an increased interest in MPS in the world due to the identification of the spectrum and frequencies of mutations in theIDUAandIDSgenes in various populations, including in Russia, and the practical availability of methods for individual molecular diagnostics. The description of the existing experimental models, their role in the study of the biochemical basis of the pathogenesis of these severe hereditary diseases and the development of various therapeutic approaches are given. Discusses the possibility of early diagnosis of MPS I and II types based on neonatal screening in order to increase the effectiveness of their prevention and treatment, as well as the advantages and disadvantages of the main approaches to the treatment of these serious diseases, such as hematopoietic stem cell transplantation, enzyme replacement and substrate-reducing therapy. A clinical example of a combination therapy for a severe form of mucopolysaccharidosis type I Hurler syndrome is presented


2020 ◽  
Vol 6 (4) ◽  
pp. 85 ◽  
Author(s):  
Vincenza Gragnaniello ◽  
Daniela Gueraldi ◽  
Laura Rubert ◽  
Francesca Manzoni ◽  
Chiara Cazzorla ◽  
...  

Mucopolysaccharidosis type I (MPS I) is a progressive lysosomal storage disease, with neurological and visceral involvement, in which early diagnosis through newborn screening (NBS) and early treatment can improve outcomes. We present our first 5 years of experience with laboratory and clinical management of NBS for MPS I. Since 2015, we have screened 160,011 newborns by measuring α-L-iduronidase (IDUA) activity and, since 2019, glycosaminoglycans (GAGs) in dried blood spot (DBS) as a second-tier test. Positive screening patients were referred to our clinic for confirmatory clinical and molecular testing. We found two patients affected by MPS I (incidence of 1:80,005). Before the introduction of second-tier testing, we found a high rate of false-positives due to pseudodeficiency. With GAG analysis in DBS as a second-tier test, no false-positive newborns were referred to our clinic. The confirmed patients were early treated with enzyme replacement therapy and bone-marrow transplantation. For both, the clinical outcome of the disease is in the normal range. Our experience confirms that NBS for MPS I is feasible and effective, along with the need to include GAG assay as a second-tier test. Follow-up of the two positive cases identified confirms the importance of early diagnosis through NBS and early treatment to improve the outcome of these patients.


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