Mucopolysaccharidosis type I (MPS I) is a rare lysosomal disorder caused by deficiency of alph-L-iduronidase. Few clinical trials have assessed the effect of enzyme replacement therapy (ERT) for this condition. We conducted an exploratory, open-label, non-randomized, multicenter cohort study of patients with MPS I. Data were collected from questionnaires completed by attending physicians at the time of diagnosis (T1; n = 34) and at a median time of 2.5 years later (T2; n = 24/34). The 24 patients for whom data were available at T2 were allocated into groups: A, no ERT (9 patients; median age at T1 = 36 months; 6 with severe phenotype); B, on ERT (15 patients; median age at T1 = 33 months; 4 with severe phenotype). For all variables in which there was no between-group difference at baseline, a delta of ;±20% was considered clinically relevant. The following clinically relevant differences were identified in group B in T2: lower rates of mortality and reported hospitalization for respiratory infection; lower frequency of hepatosplenomegaly; increased reported rates of obstructive sleep apnea syndrome and hearing loss; and stabilization of gibbus deformity. These changes could be due to the effect of ERT or of other therapies which have also been found more frequently in group B. Our findings suggest MPS I patients on ERT also receive a better overall care. ERT may have a positive effect on respiratory morbidity and overall mortality in patients with MPS I. Additional studies focusing on these outcomes and on other therapies should be performed.

A mucopolissacaridose tipo II (MPS II) é uma doença genética de amplo espectro clínico, caracterizada por deficiência da enzima iduronato-2sulfatase. Revisão sistemática avaliou a eficácia e segurança da terapia de reposição enzimática (TRE) com idursulfase (IDS) na MPS II. As bases de dados PubMed/MEDLINE, Embase, LILACS e Biblioteca Cochrane foram pesquisados até 30 de novembro de 2012. Apenas cinco estudos preencheram os critérios de inclusão (ensaios clínicos randomizados - ECRs, ECRs abertos ou séries de caso prospectivas, incluindo cinco ou mais pacientes e avaliando desfechos relevantes). Metanálise foi realizada para capacidade vital forçada (CVF; valores absolutos e em %) e para a distância percorrida no teste da caminhada dos seis minutos, com mudanças significativas em ambas as variáveis; também foi encontrado risco aumentado de reações leves relacionadas à infusão e de desenvolvimento de anticorpos IgG à IDS. Em face dos dados apresentados neste estudo, conclui-se que a TRE com IDS é segura e tem benefício potencial em MPS II, mas estudos adicionais são necessários.

Mucopolysaccharidosis type II (MPS II) is a genetic disease of broad clinical spectrum, characterized by a deficiency of the enzyme iduronate2-sulfatase. The aim of this study was to assess whether enzyme replacement therapy (ERT) with idursulfase (IDS) for MPS II is effective and safe. PubMed/MEDLINE, Embase, LILACS, and Cochrane Library were searched until November 30, 2012. Only five articles met the inclusion criteria (randomized controlled trials - RCTs, or open-label trials/prospective case series including > 5 patients and evaluating relevant outcomes). A meta-analysis was performed for forced vital capacity (FVC; absolute and %) and for distance walked on the 6-minute walking test (6MWT). There was a statistically significant increase, but not clinically relevant, in both variables; an increased risk for development of mild infusion-related reactions and IgG antibodies to IDS were also found. The data suggest that ERT with IDS is safe and has a potential benefit for MPS II patients, but further studies are required.

La mucopolisacaridosis tipo II (MPS II) es una enfermedad genética de amplio espectro clínico, caracterizada por una deficiencia de la enzima iduronato-2-sulfatasa. El objetivo fue evaluar la seguridad y eficacia de la Terapia de Reemplazo Enzimático (TRE) con idursulfasa (IDS) en la MPS II. En las bases PubMed/MEDLINE, EMBASE, LILACS y Cochrane Library se inició la búsqueda hasta el 30 de noviembre de 2012. Sólo cinco estudios cumplieron los criterios de inclusión (ensayos controlados aleatorios -ECA, o ECA abiertos o series de casos prospectivo incluyendo > 5 pacientes y evaluación de los resultados pertinentes). El metaanálisis se realizó para la capacidad vital forzada (FVC; absoluta y %) y la distancia caminada en 6 minutos, con cambios significativos en ambas variables; el riesgo también se encuentra aumentado por reacciones leves y anticuerpos IgG, relacionados con la infusión con IDS. El TRE con IDS es seguro y tiene un beneficio potencial en la MPS II, pero se necesitan estudios adicionales.

A mucopolissacaridose tipo II (MPS II) é uma doença genética de amplo espectro clínico, caracterizada por deficiência da enzima iduronato-2sulfatase. Revisão sistemática avaliou a eficácia e segurança da terapia de reposição enzimática (TRE) com idursulfase (IDS) na MPS II. As bases de dados PubMed/MEDLINE, Embase, LILACS e Biblioteca Cochrane foram pesquisados até 30 de novembro de 2012. Apenas cinco estudos preencheram os critérios de inclusão (ensaios clínicos randomizados - ECRs, ECRs abertos ou séries de caso prospectivas, incluindo cinco ou mais pacientes e avaliando desfechos relevantes). Metanálise foi realizada para capacidade vital forçada (CVF; valores absolutos e em %) e para a distância percorrida no teste da caminhada dos seis minutos, com mudanças significativas em ambas as variáveis; também foi encontrado risco aumentado de reações leves relacionadas à infusão e de desenvolvimento de anticorpos IgG à IDS. Em face dos dados apresentados neste estudo, conclui-se que a TRE com IDS é segura e tem benefício potencial em MPS II, mas estudos adicionais são necessários.

Mucopolysaccharidosis type II (MPS II) is a genetic disease of broad clinical spectrum, characterized by a deficiency of the enzyme iduronate2-sulfatase. The aim of this study was to assess whether enzyme replacement therapy (ERT) with idursulfase (IDS) for MPS II is effective and safe. PubMed/MEDLINE, Embase, LILACS, and Cochrane Library were searched until November 30, 2012. Only five articles met the inclusion criteria (randomized controlled trials - RCTs, or open-label trials/prospective case series including > 5 patients and evaluating relevant outcomes). A meta-analysis was performed for forced vital capacity (FVC; absolute and %) and for distance walked on the 6-minute walking test (6MWT). There was a statistically significant increase, but not clinically relevant, in both variables; an increased risk for development of mild infusion-related reactions and IgG antibodies to IDS were also found. The data suggest that ERT with IDS is safe and has a potential benefit for MPS II patients, but further studies are required.

La mucopolisacaridosis tipo II (MPS II) es una enfermedad genética de amplio espectro clínico, caracterizada por una deficiencia de la enzima iduronato-2-sulfatasa. El objetivo fue evaluar la seguridad y eficacia de la Terapia de Reemplazo Enzimático (TRE) con idursulfasa (IDS) en la MPS II. En las bases PubMed/MEDLINE, EMBASE, LILACS y Cochrane Library se inició la búsqueda hasta el 30 de noviembre de 2012. Sólo cinco estudios cumplieron los criterios de inclusión (ensayos controlados aleatorios -ECA, o ECA abiertos o series de casos prospectivo incluyendo > 5 pacientes y evaluación de los resultados pertinentes). El metaanálisis se realizó para la capacidad vital forzada (FVC; absoluta y %) y la distancia caminada en 6 minutos, con cambios significativos en ambas variables; el riesgo también se encuentra aumentado por reacciones leves y anticuerpos IgG, relacionados con la infusión con IDS. El TRE con IDS es seguro y tiene un beneficio potencial en la MPS II, pero se necesitan estudios adicionales.