ABSTRACT
Abstract Data on Mucopolysaccharidosis type II (MPS II) in Latin America are scarce. This retrospective database study, using data from the Informatics Department of the Brazilian Health System (DATASUS), aimed to estimate the prevalence of MPSII in Brazil from 2008 to 2020 and to describe demographic and clinical profiles from patients under treatment. The study population was derived from DATASUS records of MPS II (ICD-10 E76.1) diagnosed in Brazil. Initially 455 patients were found, but only 181 patients who were receiving idursulfase treatment were included in this study. Among these cases, as expected in a X-linked disease, all were males and 40% of the cases were recorded in the Southeast region, and another 34% in the Northeast region. The biggest proportion of patients (39%) were diagnosed when they were 10-19 years old. There are 212 clinical conditions associated with MPS II, although the main comorbidities related to MPSII include: abdominal/inguinal hernia, respiratory complications, and carpal tunnel syndrome. Respiratory disorders were the fifth most frequent comorbidity recorded in these patients. The healthcare professionals in Brazil more involved in the diagnosis of MPS II were radiologists, followed by geneticists and cardiologists. Despite some limitations, DATASUS is a relevant database to provide information on rare diseases such as MPS II. Most cases were reported in southeast and northeast regions, respectively. This information is crucial to help design targeted public policies.
ABSTRACT
PURPOSE: Mucopolysaccharidosis II (MPS II) is a lysosomal storage disorder caused by a deficiency of iduronate-2 sulfatase (IdS), which is involved in the degradation of glycosaminoglycan (GAG). In this study, the frequency of fasting hypoglycemia in patients with MPS II was investigated and changes in accumulation of glycogen and GAG in the hepatocytes of IdS-knockout (KO) mice were evaluated before and after recombinant IdS enzyme replacement therapy (ERT). MATERIALS AND METHODS: Plasma glucose levels were evaluated after an 8-hour fast in 50 patients with MPS II. The IdS-KO mice were divided into three groups (group 2; saline, group 3; 0.15 mg/kg of IdS, and group 4; 0.5 mg/kg of IdS); wild-type mice were included as controls (group 1). ERT was initiated intravenously at four weeks of age, and continued every week until 20 weeks of age. RESULTS: The mean glucose level after an 8-hour fast was 94.1 +/- 23.7 mg/dL in the patients with MPS II. Two (4%) out of 50 patients had fasting hypoglycemia. For the mice, GAG in the lysosomes nearly disappeared and glycogen particles in the cytoplasm were restored to the normal range in group 4. CONCLUSION: Glucose metabolism in patients with MPS II appeared to function well despite hepatocytic GAG accumulation and hypothetical glycogen depletion. A higher dose of IdS infusion in MPS II mice led to disappearance of lysosomal GAG and restoration of glycogen to the cytoplasm of hepatocytes.