Long-term restoration of alpha-L-iduronidase activity in fibroblasts from patients with mucopolysaccharidosis type I after non-viral gene transfer

Mucopolysaccharidosis type I (MPS I) is a lysosomal storage disorder caused by deficiency of alpha-L-iduronidase (IDUA). Limitations such as the need for weekly injections, high morbidity and mortality, and high cost of current treatments show that new approaches to treat this disease are required. In this study, we aimed to correct fibroblasts from a patient with MPS I using non-viral gene therapy. Using a plasmid encoding the human IDUA cDNA, we achieved stable high IDUA levels in transfected fibroblasts up to 6 months of treatment. These results serve as proof of concept that a non-viral approach can correct the enzyme deficiency in cells of patients with lysosomal storage disorders, which can be used as a research tool for a series of disease aspects. Future studies should focus on showing if this approach can be useful in small animals and clinical trials (AU)

Gene Therapy for Lysosomal Storage Disorders: Recent Advances and Limitations

Abstract Lysosomal storage disorders (LSDs) are a group of diseases with multisystemic features. Current treatments have limitations and gene therapy arises as a promising treatment option. Here, we discuss some of the most recent studies for gene therapy in LSD, vectors used, and outcomes. In particular, the approaches used in animal models aiming to correct the central nervous system, the eye, and the bones are highlighted. Finally, we discuss the recent reports of clinical trials using this technology for these diseases. We conclude that gene therapy for LSD has gathered a substantial amount of evidence from animal models to know its potential and limitations. First evidences from clinical trials using both adeno-associated and lentiviral vectors show that this approach is safe and efficient and therefore could provide an effective treatment for several LSD in the near future.

Enzyme Replacement Therapy With Elosulfase Alfa Decreases Storage of Glycosaminoglycan in White Blood Cells of Patients With Morquio A Syndrome

Abstract Mucopolysaccharidosis IVA (MPS IVA; Morquio A syndrome) is a lysosomal storage disorder caused by a deficient N-acetylgalactosamine-6-sulfate sulfatase activity, leading to cellular storage of undegraded keratan sulfate. Recently enzyme replacement therapy (ERT) was approved for MPS IVA, but some of ERT effects are still unknown. In the present study, we aimed to evaluate the efficacy of elosulfase alfa upon glycosaminoglycan (GAG) storage in peripheral blood white blood cells of patients with MPS IVA treated for 6 months, comparing samples from patients who received weekly infusions of enzyme (ERT-W) versus infusions every other week (ERT-EOW) versus placebo. A significant reduction in GAG storage was observed in both ERT-treated groups, with weekly ERT showing slightly better performance than ERT-EOW.

Estimativa do custo de tratar o pé diabético, como prevenir e economizar recursos / Estimate of cost for diabetic foot treatment; how to prevent it and save funds

Neste trabalho estimamos o custo do tratamento hospitalar do pé diabético e discutimos a literatura referente à profilaxia destas lesões. Para isto revisamos os prontuários dos pacien tes submetidos a tratamento cirúrgico num período de 16 meses em um hospital público e revisamos os métodos de prevenção do pé diabético. Foram 44 internações com duração média de 11,93 dias (± 6,34), 61 procedimentos cirúrgicos, com amputações em 65% dos casos. Encontramos um custo médio de R$ 4.367,05 (± 9.249,01) e um custo total de R$ 192.150,40 para estes tratamentos hospitalares. O tratamento do pé diabético teve um alto custo e exigiu amputações na maioria dos casos. A revisão da literatura evidenciou diversos modelos possíveis de serem adotados para atuar na profilaxia de lesões associadas ao pé diabético, os quais podem evitar amputações e economizar recursos.

In this work the cost of hospital treatment for diabetic foot wounds was estimated and the literature regarding prophylaxis for these lesions was examined. For this purpose, the records of all patients with diabetic foot symptoms submitted to surgical treatment over a period of 16 months in a public hospital were reviewed. There were 44 admissions with an average hospitalization period of 11.93 days, (± 6.34), 61 surgical procedures, with amputations in 65% of the cases. An average cost of R$ 4,367.05 (± 9249.01) and a total cost of R$ 192,150.40 was calculated for the hospital treatment involved. Treatment of diabetic foot symptoms had a high cost and required amputation in the majority of cases. A review of the literature revealed many possible models to be adopted for action in the prophylaxis of wounds associated with the diabetic foot, which can avoid amputations and save funds.

An effective device for generating alginate microcapsules

An alternative approach to somatic gene therapy is to deliver the therapeutic protein by implanting genetically modified cells that could overexpress the gene of interest. Microencapsulation devices were designed to protect cells from host rejection and prevent the foreign cells from spreading while allowing protein secretion. Alginate microcapsules form a semi-permeable structure that is suitable for in vivo injection. In this study, we report an effective laboratory protocol for producing calcium alginate microcapsules, following optimization of uniformly shaped and sized particles containing viable cells. Encapsulation of baby hamster kidney (BHK) cells in alginate microcapsules was performed using a simple device consisting of a cylinder of compressed air and a peristaltic pump. A cell suspension flow of 100 mL h-1 and an air jet flow of 10 L min-1 produced the best uniformity of microcapsule size and shape. Cells maintained viability in culture for 4 weeks without any signs of necrosis, and protein diffusion was observed during this period. Our results clearly demonstrated that microisolation of BHK cells in alginate using a simple assembly device could provide an environment that is capable of preserving live cells. In addition, encapsulated cells under the conditions described were able to secrete an active enzyme even after four weeks, thus becoming potentially compatible with therapeutic protein delivery.

Prevalence of the serpin peptidase inhibitor (alpha-1-antitrypsin) PI*S and PI*Z alleles in Brazilian children with liver disease

Serpin peptidase inhibitor, clade A (alpha-1 antiproteinase, antitrypsin), member 1 (SERPINA1) deficiency is one of the main genetic causes related to liver disease in children. In SERPINA1 deficiency the most frequent SERPINA1 alleles found are the PI*S and PI*Z alleles. We used the polymerase chain reaction and the amplification created restriction site (ACRS) technique to investigate the prevalence of the PI*S and PI*Z alleles in a group of Brazilian children (n = 200) with liver disease and established the general frequency of the PI*S allele in our population. We found a significant association of the PI*Z allele and liver disease, but no such relationship was found for the PI*S allele. Our results show that SERPINA1 deficiency due to the PI*Z allele, even when heterozygous, is a frequent cause of liver disease in our group of Brazilian children but that the PI*S allele does not confer an increased risk of hepatic disorders in our group of Brazilian children.

Frequência de ovos de Toxocara spp. em três parques públicos da cidade de Porto Alegre, Rio Grande do Sul, Brasil / Frequency of Toxocara spp in three public parks of Porto Alegre city-Brazil

Com o objetivo de realizar um monitoramento mensal para verificar a presença e a frequência de ovos de Toxacara spp, foram coletadas, entre fevereiro de 2002 e janeiro de 2003, 216 amostras de areia em 18 caixas, de praças de recreação localizadas em três parques públicos da cidade de Porto Alegre, Rio Grande do Sul, Brasil. As amostras foram processadas em laboratório pela técnica de Faust modificada, sendo que os resultados mostraram ema frequência de ovos de Toxocara spp em 77,7 por cento das caixas examinadas. Esses dados indicam a necessidade da implantação de medidas sanitárias e educativas visando à prevenção do risco de contaminação da população, especialmente a infantil, por parasitos causadores da larva migrans visceral.